Microorganism Removal in Permeable Pavement Parking Lots ...
Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.
DOT National Transportation Integrated Search
2013-05-01
University of New Hampshire Stormwater Center (UNHSC) completed a two year field verification study of a permeable interlocking concrete pavement (PICP) stormwater management system. The purpose of this study was to evaluate the cold climate function...
Pervious Pavement System Evaluation-Poster
Pervious pavement is a low impact development stormwater control. The Environmental Protection Agency's Urban Watershed Management Branch is evaluating interlocking concrete pavingstone pervious pavement systems. The pavingstones themselves are impermeable, but the spaces between...
Refining the maintenance techniques for Interlocking Concrete Paver GIs
Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. The clogging rate is a function of pavement type, traffic loading, surrounding physical environment and maintenance treatments. ...
Refining the maintenance techniques for Interlocking Concrete Paver GIs - abstract
Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. Determining the correct methods for remedial maintenances is crucial to recovering and maintaining efficient ICP performance. T...
Pervious Pavement System Evaluation
Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, grade...
The Utilisation of Shredded PET as Aggregate Replacement for Interlocking Concrete Block
NASA Astrophysics Data System (ADS)
Mokhtar, M.; Kaamin, M.; Sahat, S.; Hamid, N. B.
2018-03-01
The consumption of plastic has grown substantially all over the world in recent years and this has created huge quantities of plastic-based waste. Plastic waste is now a serious environmental threat to the modern way of living, although steps were taken to reduce its consumption. This creates substantial garbage every day, which is much unhealthy. Plastic bottles such as Polyethylene terephthalate (PET) was use as the partially component in this making of interlocking blocks concrete. This project investigates the strength and workability of the interlocking block concrete by replacing course aggregate with % PET. The suitability of recycled plastics (PET) as course aggregate in interlocking block concrete and its advantages are discussed here. Moreover, there were more benefits when using interlocking block than using conventional block such as it easy for construction because they are aligning, easy to place, high speed stacking and they offer more resistance to shear and buildings would be even stronger. Based on the test perform, the failure parameter were discussed .From the compressive strength test result, it shows that the strength of concrete block decreased with increased of PET used. From the results, it shows that higher compressive strength was found with 5% natural course aggregate replaced with PET compared to other percentages.
Pervious Pavement System Evaluation- Abstract
Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...
Pervious Pavement System Evaluation- Abstract 1
Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...
Pervious Pavement System Evaluation-Paper
The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...
Friction evaluation of concrete paver blocks for airport pavement applications
NASA Technical Reports Server (NTRS)
Yager, Thomas J.
1992-01-01
The development and use of concrete paver blocks is reviewed and some general specifications for application of this type of pavement surface at airport facilities are given. Two different shapes of interlocking concrete paver blocks installed in the track surface at NASA Langley's Aircraft Landing Dynamics Facility (ALDF) are described. Preliminary cornering performance results from testing of 40 x 14 radial-belted and bias-ply aircraft tires are reviewed. These tire tests are part of a larger, ongoing joint NASA/FAA/Industry Surface Traction and Radial Tire (START) Program involving several different tire sizes. Both dry and wet surface conditions were evaluated on the two concrete paver block test surfaces and a conventional, nongrooved Portland cement concrete surface. Future test plans involving evaluation of other concrete paver block designs at the ALDF are indicated.
Evaluating load transfer restoration, districts 1 and 3
DOT National Transportation Integrated Search
2002-07-01
Since 1950, concrete pavements in California have been constructed without dowel bars in the transverse joints, Consequently, aggregate interlock has been the primary mechanism for load transfer across adjacent slabs. As the pavements age, the aggreg...
Effects of Interlocking and Supporting Conditions on Concrete Block Pavements
NASA Astrophysics Data System (ADS)
Mahapatra, Geetimukta; Kalita, Kuldeep
2018-02-01
Concrete Block Paving (CBP) is widely used as wearing course in flexible pavements, preferably under light and medium vehicular loadings. Construction of CBP at site is quick and easy in quality control. Usually, flexible pavement design philosophy is followed in CBP construction, though it is structurally different in terms of small block elements with high strength concrete and their interlocking aspects, frequent joints and discontinuity, restrained edge etc. Analytical solution for such group action of concrete blocks under loading in a three dimensional multilayer structure is complex and thus, the need of conducting experimental studies is necessitated for extensive understanding of the load—deformation characteristics and behavior of concrete blocks in pavement. The present paper focuses on the experimental studies for load transfer characteristics of CBP under different interlocking and supporting conditions. It is observed that both interlocking and supporting conditions affect significantly on the load transfer behavior in CBP structures. Coro-lock block exhibits better performance in terms of load carrying capacity and distortion behavior under static loads. Plate load tests are performed over subgrade, granular sub-base (GSB), CBP with and without GSB using different block shapes. For an example case, the comparison of CBP with conventional flexible pavement section is also presented and it is found that CBP provides considerable benefit in terms of construction cost of the road structure.
Selvakumar, Ariamalar; O'Connor, Thomas P
2018-01-01
Three types of permeable pavements were monitored at the Edison Environmental Center in Edison, New Jersey, for indicator organisms such as fecal coliform, enterococci, and Escherichia coli. Results showed that porous asphalt had a much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers; concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard and actually had limited detection. Fecal coliform and enterococci exceeded bathing water quality standards more than 72 and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Concentration reductions greater than 90% were observed for all three indicator organisms for porous asphalt and fecal coliform and E. coli for pervious concrete when compared to runoff values, while permeable interlocking concrete pavers only had a modest (39%) observable reduction for E. coli only. The near absence of indicator organisms observed in the porous asphalt infiltrate may be due to the high pH potentially due to asphalt processing. Neither rain intensity nor temperature was demonstrated to have an observable effect in both concentrations of organisms and performance of permeable pavement; but this may due to the limitations of the dataset consisting of 16 events over an 8-month period.
Long-term infiltration capacity of different types of permeable pavements.
DOT National Transportation Integrated Search
2017-08-01
Permeable pavements such as porous asphalt, pervious concrete and permeable interlocking concrete pavers are relatively novel alternatives to conventional pavement that allow rain and snowmelt to infiltrate, thereby reducing runoff, flooding and nonp...
Repair of earthquake-damaged bridge columns with interlocking spirals and fractured bars.
DOT National Transportation Integrated Search
2014-07-01
During earthquakes, reinforced concrete (RC) bridge columns may experience different levels of damage such as cracking, spalling, or crushing of concrete and yielding, buckling, or fracture of reinforcing bars. Although several repair options exist f...
Detection of semi-volatile organic compounds in permeable pavement infiltrate
Abstract The Edison Environmental Center (EEC) has a research and demonstration permeable parking lot comprised of three different permeable systems: permeable asphalt, porous concrete and interlocking concrete permeable pavers. Water quality and quantity analysis has been ongoin...
Permeable Pavement Research - Edison, New Jersey
This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...
Long-term Metal Performance of Three Permeable Pavements
EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected...
Nitrogen Transformations in Three Types of Permeable Pavement
In 2009, USEPA constructed a 0.4-ha (1-ac) parking lot at the Edison Environmental Center in Edison, NJ, that incorporated three different permeable pavement types - permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). The driving lanes...
Performances of Metal Concentrations from Three Permeable Pavement Infiltrates
The U.S. Environmental Protection Agency designed and constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements: permeable interlocking concrete pavers, pervious concrete, and porous asphalt. Water sampling was con...
Microorganism Removal in Permeable Pavement Parking Lots in Edison Environmental Center, New Jersey
Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed tha...
This project will provide a scientifically defensible estimate of the performance of the three permeable surfaces: porous concrete, porous asphalt, and interlocking concrete pavers. The U.S. Environmental Protection Agency (EPA) can provide the results to municipalities enabling...
Performances of Metal Concentrations from Three Permeable Pavement Infiltrates
The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...
Correlation of Water Quality Parameters with Metal Concentrations in Permeable Pavement Infiltrate
EPA constructed a 4,000-m2 parking lot for research and demonstration of three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)] at the Edison Environmental Center in Edison, NJ in 2009. Infiltrate samples from e...
EPA constructed a 4,000-m2 parking lot for research and demonstration of three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)] at the Edison Environmental Center in Edison, NJ in 2009. Infiltrate samples from e...
NASA Astrophysics Data System (ADS)
Malahayati, Nurul; Hayati, Yulia; Nursaniah, Cut; Firsa, T.; Fachrurrazi; Munandar, Aris
2018-05-01
Red brick and interlocking brick are the building materials that are often used for wall installation work on houses construction. In the development of building materials technology and cost savings, interlocking brick can be alternative to replace red bricks. In Aceh Province, the use of interlocking bricks is less popular compared to other big cities in Indonesia. Interlocking brick is made from a mixture of clay, concrete sand and compacted cement and one of the environmentally friendly materials because it does not burn the process like red brick material. It is named interlocking brick because the installation method is locked together and it serves as a structural and partition wall of residential buildings. The aims of this study are to compare the cost of building a house in Banda Aceh City using red brick and interlock brick building materials. The data were obtained from interviews and questionnaires distributed to respondents who had built houses in Banda Aceh City. The results concluded that the house construction cost using interlock brick offer lower construction cost at comparable quality rather than using red brick.
The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...
Koontz, Alicia M; Cooper, Rory A; Boninger, Michael L; Yang, Yusheng; Impink, Bradley G; van der Woude, Lucas H V
2005-01-01
The objective of this study was to conduct a kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces. Eleven manual wheelchairs were fitted with a SMART(Wheel) and their users were asked to push on a course consisting of high- and low-pile carpet, indoor tile, interlocking concrete pavers, smooth level concrete, grass, hardwood flooring, and a sidewalk with a 5-degree grade. Peak resultant force, wheel torque, mechanical effective force, and maximum resultant force rate of rise were analyzed during start-up for each surface and normalized relative to their steady-state values on the smooth level concrete. Additional variables included peak velocity, distance traveled, and number of strokes in the first 5 s of the trial. We compared biomechanical data between surfaces using repeated-measures mixed models and paired comparisons with a Bonferroni adjustment. Applied resultant force (p = 0.0154), wheel torque (p < 0.0001), and mechanical effective force (p = 0.0047) were significantly different between surfaces. The kinetic values for grass, interlocking pavers, and ramp ascent were typically higher compared with tile, wood, smooth level concrete, and high- and low-pile carpet. Users were found to travel shorter distances up the ramp and across grass (p < 0.0025) and had a higher stroke count on the ramp (p = 0.0124). While peak velocity was not statistically different, average velocity was slower for the ramp and grass, which indicates greater wheelchair/user deceleration between strokes. The differences noted between surfaces highlight the importance of evaluating wheelchair propulsion ability over a range of surfaces.
The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...
In 2009, the U.S. Environmental Protection Agency constructed a 0.4-ha (1-ac) parking lot surfaced with three different permeable pavement types (interlocking concrete pavers, porous concrete, and porous asphalt) and six bioinfiltration areas with three different drainage area to...
Long-term Metal Performance of Three Permeable Pavements ...
EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected for six years beginning in January 2010 and analyzed for twenty-two metals. Although the infiltrate metals concentrations varied by surface, metal concentrations in more than 99% of the permeable pavement infiltrate samples met both the groundwater effluent limitations and maximum contaminant levels in national primary drinking water regulations for barium, chromium, copper, manganese, nickel and zinc. Arsenic, cadmium, lead and antimony met those standards in 60% to 98% of the samples with no measurable difference found among pavements. Aluminum and iron in pervious concrete and porous asphalt infiltrates met standards at more than 90%, however permeable interlocking concrete paver infiltrates have 50% and 93% samples exceeds standards, respectively. Concentrations of arsenic, iron, potassium, lithium, magnesium, antimony, tin, manganese, and zinc in all permeable pavement infiltrates decreased with time, whereas, aluminum, barium, calcium, chromium and strontium in porous asphalt infiltrates increased. Most metal concentrations in permeable pavement infiltrates either exhibited no significant difference between snow/no-snow seasons or showed statistically larger concentrations
Preliminary study of tin slag concrete mixture
NASA Astrophysics Data System (ADS)
Hashim, Mohd Jamil; Mansor, Ishak; Pauzi Ismail, Mohamad; Sani, Suhairy; Azmi, Azhar; Sayuti, Shaharudin; Zaidi Ibrahim, Mohd; Adli Anuar, Abul; Rahim, Abdul Adha Abdul
2018-01-01
The study focuses on practices to facilitate tin smelting industry to reduce radioactive waste product (Tin Slag) by diluting its radioactivity to a safe level and turning it to a safer infrastructural building product. In the process the concrete mix which include Portland cement, sand, tin slag, water and plasticizer are used to produce interlocking brick pavements, piles and other infrastructural products. The mixing method follows DOE (UK) standard method of mixing targeted at in selected compressive strength suitable for its function and durability. A batching machine is used in the mixing and six test cubes are produced for the test. The testing equipment used are a compressional machine, ultrasonic measurement and a Geiger Muller counter to evaluate of the concrete mix to find the lowest emission of radiation surface dose without compromising the strength of concrete mix. The result obtained indicated the radioactivity of tin slag in the mixing process has reduced to background level that is 0.5μSv/h while the strength and workability of the concrete has not been severely affected. In conclusion, the concrete mix with tin slag has shown the potential it can be turned into a safe beneficial infrastructural product with good strength.
Update to permeable pavement research at the Edison Environmental Center - slides
Abstract: The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable paver...
Update to Permeable Pavement Research at the Edison Environmental Center - abstract
Abstract The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable pavers...
Kim, Kyeongjin; Park, Sangmin; Jeong, Yoseok; Lee, Jaeha
2017-01-01
With the recent development of 3D printing technology, concrete materials are sometimes used in 3D printing. Concrete structures based on 3D printing have been characterized to have the form of multiple layer build-up. Unlike general concrete structures, therefore, the 3D-printed concrete can be regarded as an orthotropic material. The material property of the 3D-printed concrete’s interface between layers is expected to be far different from that of general concrete bodies since there are no aggregate interlocks and weak chemical bonding. Such a difference finally affects the structural performance of concrete structures even though the interfaces are formed before initial setting of the concrete. The current study mainly reviewed the changes in fracture energy (toughness) with respect to various environmental conditions of such interface. Changes in fracture energies of interfaces between concrete layers were measured using low-speed Crack Mouth Opening Displacement (CMOD) closed loop concrete fracture test. The experimental results indicated reduction in fracture energy as well as tensile strengths. To improve the tensile strength of interfaces, the use of bridging materials is suggested. Since it was assumed that reduction in fracture energy could be a cause of shear strength, to evaluate the reduced structural performance of concrete structure constructed with multiple interfaces by 3D printing technology, the shear strength of RC beam by 3D printing technology was predicted and compared with that of plain RC beam. Based on the fracture energy measured in this study, Modified Compression Field Theory (MCFT) theory-applied Vector 2 program was employed to predict the degree of reduction in shear strength without considering stirrups. Reduction factors were presented based on the obtained results to predict the reduction in shear strength due to interfaces before initial setting of the concrete.
A review on past and present development on the interlocking loadbearing hollow block (ILHB) system
NASA Astrophysics Data System (ADS)
Bosro, M. Z. M.; Samad, A. A. A.; Mohamad, N.; Goh, W. I.; Tambichik, M. A.; Iman, M. A.
2018-04-01
Massive migration and increasing population in Malaysia has contributed to the increasing demand of quality and affordable housing. Over the past 50 years, the Malaysian housing industry has seen the growth of using conventional construction system such as reinforced concrete frame structures and bricks. The conventional system, as agreed by many researchers, causes delays and other disadvantages in some of the construction projects. Thus, the utilization of interlocking loadbearing hollow block (ILHB) system is needed to address these issues. This system has been identified as an alternative and sustainable building system for the construction industry in Malaysia which the PUTRA block system is the latest example of the ILHB developed. The system offers various advantages in terms of speed and cost in construction, strength, environmentally friendly and aesthetic qualities. Despite these advantages, this system has not been practically applied and develop in Malaysia. Therefore, this paper aims to review the past and present development of the interlocking loadbearing hollow block (ILHB) system that available locally and globally.
Evaluation of state ignition interlock programs : interlock use analyses from 28 states, 2006–2011.
DOT National Transportation Integrated Search
2015-05-01
In 2010, the Centers for Disease Control and Prevention (CDC) and NHTSA began collaborating on a project to evaluate ignition interlock programs in selected States. The purpose of the evaluation was to provide information and best practices to States...
Effects of climate and corrosion on concrete behaviour
NASA Astrophysics Data System (ADS)
Ismail, Mohammad; Egba, Ernest Ituma
2017-11-01
Corrosion of steel is a damaging agent that reduces the functional and structural responsibilities of reinforced concrete structures. Accordingly, reinforced concrete members in the environments that are prone to concrete carbonation or chloride attack coupled with high temperature and relative humidity suffer from accelerated corrosion of reinforcing material. Also, literature proves that climate influences corrosion of concrete, and suggests investigation of impact of corrosion on concrete based on climate zone. Therefore, this paper presents the effects of climate and corrosion on concrete behavior, using bond strength of concrete as a case study. Concrete specimens were prepared form concrete mix that was infested with 3.5 kgm-3 of sodium chloride to accelerate corrosion. The specimens were cured sodium chloride solution 3.5% by weight of water for 28 days before placing them in the exposure conditions. Pull-out tests were conducted at time intervals for one year to measure the impact of exposure condition and corrosion on bond strength of concrete. The results show reduction of bond strength of concrete by 32%, 28% and 8% after one year of subjection of the specimens to the unsheltered natural climate, sheltered natural climate, and laboratory ambient environment respectively. The findings indicate that the climate influences corrosion, which reduces the interlocking bond between the reinforcing bar and the adjacent concrete.
Evaluation of the New Mexico ignition interlock program.
DOT National Transportation Integrated Search
2010-11-01
This Evaluation of the New Mexico Ignition Interlock Program begins by summarizing the development of : alcohol ignition interlock devices, laws, and programs during the past 22 years. It then reviews the laws that : were written in New Mexico from 1...
SU-E-T-243: Design of a Novel Testing Port for Radiation Protection and Shielding Measurements
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tanny, S; Parsai, E; Harrell, D
2015-06-15
Purpose: The majority of radiation shielding research utilizes Monte Carlo simulation because of the difficulty in eliminating secondary radiations from measurements. We have designed a test port into a primary barrier of our newest vault to allow for shielding measurements while ensuring adequate protection to the public and staff during normal machine operation. This port allows for measurement of attenuation values of shielding materials, differential dose albedos, and radiation scatter fractions. Methods: The vault design utilized the maze as part of a compound primary barrier. The test port is contained within the maze and is centered along isocenter. The innermore » 30 cm has a 20×20 cm{sup 2} opening, while the remaining length has a 30×30 cm{sup 2} opening. The block that contains the port has a density of 200 pcf to minimize internal scatter. The 30×30 cm{sup 2} opening is occupied by removable 215 pcf concrete blocks. The innermost and outermost blocks activate an interlock wired into the beam-enable loop. This disallows beam-on in treatment mode if the interlock isn’t closed. The interlock can be overridden in service mode, or by-passed via an override switch in case of circuit failure. Results: The test port was installed in August. The beam is disabled when the interlock is tripped. Measurements taken when the primary beam is not incident on the port are indistinguishable from background. Ambient dose levels surrounding the vault with the designed shielding blocks in place are all within allowable limits for occupational workers. Conclusions: We have designed and installed a unique testing port for radiation protection and shielding measurements. This port is appropriately interlocked and designed to mitigate any risks of incidental exposure to staff or members of the public. The test port design allows measurements with “good geometry” and efficient removal of contaminating sources of radiation present in many shielding measurements. Daniel Harrell and Jim Noller are employees of Shielding Construction Solutions, Inc, the shielding construction company that built the vault discussed in this abstract. Manjit Chopra is an employee of Universal Minerals International, Inc, the company that provided the aggregates for the high density concretes used in the vault construction.« less
NASA Astrophysics Data System (ADS)
Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam
2017-08-01
Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.
Effect of rubber flooring on claw health in lactating dairy cows housed in free-stall barns.
Vanegas, J; Overton, M; Berry, S L; Sischo, W M
2006-11-01
Multiparous dairy cows between 10 to 30 d in milk (DIM) were enrolled in a clinical trial to evaluate the effects of rubber flooring on the development of claw lesions, locomotion scores, clinical lameness, and rates of hoof growth and wear. Two groups of cows were housed in identical free-stall facilities, except that 1 pen (rubber, n = 84) had rubber alley mats covering the entire concrete floor of the pen, whereas cows in the second pen were exposed to concrete flooring (concrete, n = 82) without rubber alley mats. All cows were evaluated 3 times between 10 and 30, 74 and 94, and 110 and 130 DIM for 1) the presence of claw lesions on their rear feet, 2) the occurrence of clinical lameness based on a locomotion score, and 3) rates of claw growth and wear as observed on the dorsal wall of the right lateral claw. No differences between flooring groups at the time of enrollment were detected for lactation number, mean DIM at first examination, body condition score, and proportion of cows with claw lesions at the first examination. Odds of developing claw lesions between examinations were not different for cows exposed to the rubber surface compared with those exposed to concrete. Cows on concrete, however, had greater odds of developing or exacerbating existing heel erosion than cows on rubber flooring. Regardless of the flooring surface, the lateral claw was more likely to develop lesions than the medial claw. Odds of becoming lame by the third examination and the proportion of cows requiring therapeutic hoof trimming because of lameness were greater for concrete-exposed cows than those on rubber. Cows on rubber flooring had decreased claw growth and wear between the first and last examination compared with cows on concrete. Regardless of flooring surface, second-lactation cows had greater wear rates than those in third or greater parities. Results of our study suggest that a soft flooring surface, such as interlocking rubber, is beneficial for hoof health.
Update to permeable pavement research at the Edison ...
Abstract: The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable pavers; porous concrete; and permeable asphalt. The parking lot is instrumented with water content reflectometers and thermistors for continuous monitoring and has four lined sections for each surface to capture permeable pavement infiltrate for water quality analyses.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, and infiltration and evaporation rates. Thispresentation summarizes past findings and addresses current water quality efforts. This presentation summarizes past findings and addresses current water quality efforts.
Economic aspects of interlocking hollow brick system designed for industrialized building system
NASA Astrophysics Data System (ADS)
Tahir, Mahmood Md.; Saggaff, Anis; Ngian, Shek Poi; Sulaiman, Arizu
2017-11-01
Construction industry has moved forward into a technology driven where a transition is in progress from conventional method to a more advanced and mechanised system known as the Industrialised Building System (IBS). However, the need to implement the IBS should be well understood by all construction players such as designer, architect, contraction, erectors and construction workers. Therefore, there is a need to educate all these construction players which should be spearheaded by authorities such as Construction Industrial Development Board where enforcement trough building by laws as well as initiative to those that adopt the IBS in their construction. This paper reports on economic aspects of using interlocking hollow brick system in construction as an alternative method offered for Industrialized Building System. The main objective is to address the economic aspects of using interlocking block system in terms of time, costs, and utilization of manpower and to present some of the experimental tests results related to Interlocking Hollow Brick System (IHBS). Example of savings from the use of IHBS is presented in this paper by comparing the construction of two storey terrace house with build-up area of about 200 square meter with conventional construction method of typical reinforced concrete construction (RCC) compared to IHBS. The comparison shows that the implementation of IHBS can reduce construction time, cost, and utilization of man power up to 26.6% compared to the conventional method. Moreover, the construction time using IHBS can also be reduced by up to 50% as compared to the conventional construction.
Marques, Paul R; Tippetts, A Scott; Yegles, Michel
2014-01-01
This study focuses on the predictive and comparative significance of ethyl glucuronide measured in head hair (hEtG) for estimating risks associated with alcohol-impaired driving offenders. Earlier work compared different alcohol biomarkers for estimating rates of failed blood alcohol concentration (BAC) tests logged during 8 months of interlock participation. These analyses evaluate the comparative performance of several alcohol markers including hEtG and other markers, past driver records, and psychometric assessment predictors for the detection of 4 criteria: new driving under the influence (DUI) recidivism, alcohol dependence, and interlock record variables including fail rates and maximal interlock BACs logged. Drivers charged with alcohol impairment (DUI) in Alberta, Canada (n = 534; 64% first offenders, 36% multiple offenders) installed ignition interlock devices and consented to participate in research to evaluate blood-, hair-, and urine-derived alcohol biomarkers; sit for interviews; take psychometric assessments; and permit analyses of driving records and interlock log files. Subject variables included demographics, alcohol dependence at program entry, preprogram prior DUI convictions, postenrollment new DUI convictions, self-reported drinking assessments, morning and overall rates of failed interlock BAC tests, and maximal interlock BAC readings. Recidivism, dependence, high BAC, and combined fail rates were set as criteria; other variables were set as predictors. Area under the receiver operating characteristics (ROC) curve (A') estimates of sensitivity and specificity were calculated. Additional analyses were conducted on baseline hEtG levels. Driver performance and drinking indicators were evaluated against the standard hEtG cutoff for excessive drinking at (30 pg/mg) and a higher criterion of 50 pg/mg. HEtG splits were evaluated with the Mann-Whitney rank statistic. HEtG emerged as a top overall predictor for discriminating new recidivism events that occur after interlock installation, for entry alcohol dependence, and for the highest interlock BACs recorded. Together, hEtG and phosphatidylethanol (PEth) were the top predictors of all criterion measures. By contrast, the hair-derived alcohol biomarkers hEtG and hFAEE (fatty acid ethyl esters) were poorer than other alcohol biomarkers as detectors of interlock BAC test fail rates. This study showed that hEtG, an objective alternative to often unreliable self-reported past representation of drinking levels, yields crucial insight into driver alcohol-related risks early in an interlock program and is a top predictor of new recidivist events. Together with PEth, these markers would be excellent anchors in a panel for detecting alcohol consumption.
Administrative Reinstatement Interlock Programs: Florida, a 10-Year Study
Voas, Robert B.; Tippetts, A. Scott; Grosz, Milton
2013-01-01
Background Interlocks reduce driving-under-the-influence (DUI) recidivism by 64%, but offenders resist installing them, preferring to risk driving while their driver’s licenses are revoked. One method of motivating offenders to install an interlock is require it for reinstatement of their driver’s license. This report updates an earlier evaluation of the administrative reinstatement interlock program (ARIP) procedure implemented in Florida in 2002. Method Driver records and interlock program records covering 120,000 DUI offenders were followed over 10 years. The flow through the sanction system—conviction, reinstatement, interlock program, and postinterlock period—is described. Logistical regression was used to identify the characteristics of offenders who installed interlocks, and survival analysis was used to evaluate the recidivism of offenders in the various stages in the ARIP. Results At any given time, approximately one third of the convicted offenders were serving their license-revocation periods. Half of the offenders who completed their revocation periods remain unqualified for reinstatement because they do not fulfill other requirements. ARIP offenders who do qualify for reinstatement and install interlocks have lower recidivism rates while the devices are on their vehicles. Conclusions After 10 years, Florida’s ARIP is a mature system that succeeds in forcing all offenders in the program who qualify for reinstatement to install an interlock for at least 6 months. However, half of all offenders who complete their mandatory revocation period are either unable to, or choose not to, qualify for reinstatement. PMID:23442206
Laboratory evaluation of alcohol safety interlock systems. Volume 1 : summary report
DOT National Transportation Integrated Search
1974-01-01
The report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were developed...
An evaluation of Nova Scotia's alcohol ignition interlock program.
Vanlaar, Ward G M; Mainegra Hing, Marisela; Robertson, Robyn D
2017-03-01
Alcohol ignition interlock programs for offenders aim to reduce recidivism among convicted drink drivers. This study presents an evaluation of Nova Scotia's interlock program implemented in 2008 in order to assess its effectiveness to reduce impaired driving and to help identify areas for improvement. Data used include conviction and crash records of individual participants; provincial monthly counts of alcohol-related charges, convictions and fatal and serious crashes; and interlock logged events. Methods used include descriptive statistics, survival analysis, time series and logistic regression analysis. With respect to specific deterrence (i.e., preventing recidivism) there was a 90% reduction in recidivism among voluntary participants since participation in the interlock program and a 79% reduction after these participants exited from the program. With respect to general deterrence (i.e., referring to a preventative effect on the entire population of drivers in Nova Scotia) there were temporary decreases in the numbers of alcohol-related charges (13.32%) and convictions (9.93%) and a small significant decrease in the number of fatal and serious injury alcohol-related crashes, following the implementation of the program. The evidence suggests the interlock program was better at preventing harm due to alcohol-impaired driving than the alternative of not using the interlock program. Recommendations were formulated supporting the continuation of the interlock program in Nova Scotia. Copyright © 2017 Elsevier Ltd. All rights reserved.
Summary and evaluation of responses received on the alcohol safety interlock system
DOT National Transportation Integrated Search
1971-05-01
This report summarizes and evaluates devices and suggestions provided by respondents to the DOT Prospectus entitled "Some Considerations Related to the Development of an Alcohol Safety Interlock System (ASIS)". The responses are categorized into: (1)...
DOT National Transportation Integrated Search
1974-01-01
The report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were developed...
DOT National Transportation Integrated Search
1974-01-01
This report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were develope...
New Approach to Road Construction in Oil-Producing Regions of Western Siberia
NASA Astrophysics Data System (ADS)
Piirainen, V. Y.; Estrin, Y.
2017-10-01
This article presents, as a polemic exercise, a new approach to road construction in marshland areas of oil and gas producing regions of Western Siberia. The approach is based on the use of novel modular elements that can be assembled into an integral structure by means of topological interlocking. The use of modern superlight concrete in conjunction with the new design systems based on the modular principle opens up new avenues to solving problems of road construction in regions with unstable, boggy soils.
Strength Calculation of Inclined Sections of Reinforced Concrete Elements under Transverse Bending
NASA Astrophysics Data System (ADS)
Filatov, V. B.
2017-11-01
The authors propose a design model to determine the strength of inclined sections of bent reinforced concrete elements without shear reinforcement for the action of transverse force taking into account the aggregate interlock forces in the inclined crack. The calculated dependences to find out the components of forces acting in an inclined section are presented. The calculated dependences are obtained from the consideration of equilibrium conditions of the block over the inclined crack. A comparative analysis of the experimental values of the failure loads of the inclined section and the theoretical values obtained for the proposed dependencies and normative calculation methods is performed. It is shown that the proposed design model makes it possible to take into account the effect the longitudinal reinforcement percentage has on the inclined section strength, the element cross section height without the introduction of empirical coefficients which contributes to an increase in the structural safety of design solutions including the safety of high-strength concrete elements.
Voas, Robert B.; Tippetts, S. Scott; Fisher, Deborah; Grosz, Milton
2015-01-01
Aims To evaluate a new method being used by some states for motivating interlock installation by requiring it as a prerequisite to reinstatement of the driver’s license. Design The driving records of Florida DWI offenders convicted between July 2002 and June 2008 were analyzed to determine the proportion of offenders subject to the interlock requirement who installed interlocks. Setting Most driving-while-impaired (DWI) offenders succeed in avoiding state laws requiring the installation of a vehicle alcohol interlock. Participants A total of 82 318 Florida DWI offenders. Findings Due to long periods of complete suspension when no driving was permitted and the failure to complete all the requirements imposed by the court, only 21 377 of the 82 318 offenders studied qualified for reinstatement, but 93% of those who qualified did install interlocks to be reinstated. Conclusions Because of the lengthy license suspensions and other barriers that the offenders face in qualifying for reinstatement, it is not clear that requiring a period on the interlock as a prerequisite to reinstating will greatly increase the current installment rate. PMID:20528811
NASA Astrophysics Data System (ADS)
Umi, N. N.; Norazman, M. N.; Daud, N. M.; Yusof, M. A.; Yahya, M. A.; Othman, M.
2018-04-01
Green building technology and sustainability development is current focus in the world nowadays. In Malaysia and most tropical countries the maximum temperature recorded typically at 35°C. Air-conditioning system has become a necessity in occupied buildings, thereby increasing the cost of electric consumption. The aim of this study is to find out the solution in minimizing heat transfer from the external environment and intentions towards going green. In this study, the experimental work includes testing three types of concrete wall panels. The main heat intervention material in this research is 2 inch diameter Polyvinyl Chloride (PVC) pipe embedded at the center of the concrete wall panel, while the EPS foam beads were added to the cement content in the concrete mix forming the outer layer of the wall panel. Water from the rainwater harvesting system is regulated in the PVC pipe to intervene with the heat conductivity through the wall panel. Results from the experimental works show that the internal surface temperature of these heat resistance wall panels is to 3□C lower than control wall panel from plain interlocking bricks.
Experimental evaluation of second-generation alcohol safety-interlock systems
DOT National Transportation Integrated Search
1978-01-01
Author's absract: This report documents the results of laboratory testing of four "second-generation" alcohol safety-interlock systems. As a group, these systems were found to produce appreciable discrimination between sober and intoxicated subjects.
Evaluation of the New Mexico ignition interlock program : traffic tech.
DOT National Transportation Integrated Search
2010-11-01
Impaired driving is a major factor in vehicle crashes and traffic : fatalities. The use of ignition interlocks is growing as a : countermeasure to combat the high rate of offender recidivism : for driving while intoxicated (DWI). New Mexico currently...
Ma, Tracey; Byrne, Patrick A; Bhatti, Junaid A; Elzohairy, Yoassry
2016-10-01
Drinking and driving is a major risk factor for traffic injuries. Although ignition interlocks reduce drinking and driving while installed, several issues undermine their implementation including delayed eligibility for installation, low installation once eligible, and a return to previous risk levels after de-installation. The Canadian province of Ontario introduced a "Reduced Suspension with Ignition Interlock Conduct Review" Program, significantly changing pre-existing interlock policy. The Program incentivizes interlock installation and an "early" guilty plea. It also attempts to reduce long-term recidivism through behavioural feedback and compliance-based removal. This evaluation is the first in assessing Program impact. Ontario drivers with a first time alcohol-impaired driving conviction between July 1, 2005 and November 25, 2014 comprised the study cohort. Longitudinal analyses, using interrupted time series and Cox regression, were conducted in which exposure was the Program and the outcomes were ignition interlock installation (N=30,200), pre-trial elapsed time (N=30,200), and post-interlock recidivism (N=9326). After Program implementation, installation rates increased by 54% and pre-trial elapsed time decreased by 146 days. Results suggest no effect on post-interlock recidivism. Through an incentive-based design, this Program was effective at addressing two commonly cited barriers to interlock implementation- delayed eligibility for installation and low installation once eligible. Results reveal that installation rates are responsive not only to incentivization but also to other external factors, thus presenting an opportunity for policy makers to find unique ways to influence interlock uptake, and thereby, to extend their deterrent effects to a larger subset of the population. This study is one of the few that do not rely on proxy measures of installation rate. Copyright © 2016 Crown. Published by Elsevier Ltd.. All rights reserved.
Li, Hui; Kayhanian, Masoud; Harvey, John T
2013-03-30
Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.
Sañudo-Fontaneda, Luis A; Charlesworth, Susanne M; Castro-Fresno, Daniel; Andres-Valeri, Valerio C A; Rodriguez-Hernandez, Jorge
2014-01-01
Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the 'Laboratorio Caminos Santander' permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance.
Evaluation and application of a fast module in a PLC based interlock and control system
NASA Astrophysics Data System (ADS)
Zaera-Sanz, M.
2009-08-01
The LHC Beam Interlock system requires a controller performing a simple matrix function to collect the different beam dump requests. To satisfy the expected safety level of the Interlock, the system should be robust and reliable. The PLC is a promising candidate to fulfil both aspects but too slow to meet the expected response time which is of the order of μseconds. Siemens has introduced a ``so called'' fast module (FM352-5 Boolean Processor). It provides independent and extremely fast control of a process within a larger control system using an onboard processor, a Field Programmable Gate Array (FPGA), to execute code in parallel which results in extremely fast scan times. It is interesting to investigate its features and to evaluate it as a possible candidate for the beam interlock system. This paper publishes the results of this study. As well, this paper could be useful for other applications requiring fast processing using a PLC.
DOT National Transportation Integrated Search
1990-01-01
This project was initiated at the request of the Department of Motor Vehicles as a response to House Joint Resolution 378 (1989). The resolution requested an evaluation of research studies on ignition interlocks and a determination of possible benefi...
Kidd, David G; Singer, Jeremiah; Huey, Richard; Kerfoot, Laura
2018-06-01
Seat belts reduce the risk of fatal injury in a crash, yet in 2015, nearly 10,000 people killed in passenger vehicles were unrestrained. Enhanced seat belt reminders increase belt use, but a gearshift interlock that prevents the vehicle from being placed into gear unless the seat belt is used may prove more effective. Thirty-two people with a recent seat belt citation and who admitted to not always using a seat belt as a driver were recruited as part-time belt users and asked to evaluate two new vehicles. Sixteen drove two vehicles with an enhanced reminder for one week each, and 16 drove a vehicle with an enhanced reminder for one week and a vehicle with a gearshift interlock the following week. Sixteen full-time belt users who reported always using a seat belt drove a vehicle with a gearshift interlock for one week to evaluate acceptance. Relative to the enhanced reminder, the gearshift interlock significantly increased the likelihood that a part-time belt user used a belt during travel time in a trip by 21%, and increased the rate of belt use by 16%; this effect approached significance. Although every full-time belt user experienced the gearshift interlock, their acceptance of the technology reported in a post-study survey was fairly positive and not significantly different from part-time belt users. Six part-time belt users circumvented the gearshift interlock by sitting on a seat belt, waiting for the system to deactivate, or unbuckling during travel. The gearshift interlock increased the likelihood that part-time belt users buckled up and the rate of belt use during travel relative to the enhanced reminder but could be more effective if it prevented circumvention. An estimated 718-942 lives could be saved annually if the belt use of unbuckled drivers and front passengers increased 16-21%. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.
In-Plane Behaviour of a Reinforcement Concrete Frame with a Dry Stack Masonry Panel
Lin, Kun; Totoev, Yuri Zarevich; Liu, Hongjun; Guo, Tianyou
2016-01-01
In order to improve the energy dissipation of the masonry infilled frame structure while decreasing the stiffening and strengthening effects of the infill panels, a new dry stacked panel (DSP) semi-interlocking masonry (SIM) infill panel has been developed. In this paper, the material properties of DSP and a traditional unreinforced masonry (URM) panel have been evaluated experimentally. A series of cyclic tests were performed to investigate the cyclic behaviour of the reinforcement concrete (RC) frame with different infill panels. The failure modes, damage evolution, hysteretic behaviour, stiffness degradation and energy dissipation were compared and analysed. We concluded that DSP is capable of significantly improving the seismic energy dissipation due to its hysteretic behaviour when the frame is in elastic stage without increasing the stiffness of the frame. Therefore, DSP or SIM panels can be considered as frictional dampers. Based on the experimental results, the influence of DSP was examined. Using the parallel model, the hysteretic loops of DSP subjected to different load cases were achieved. The typical full hysteretic loop for DSP could be divided into three distinct stages of behaviour: packing stage, constant friction stage and equivalent strut stage. The connection between the panel and the frame had a great effect on the transferring of different mechanical stages. The constant friction stage was verified to provide substantial energy dissipation and benefits to the ductility of the structure, which, therefore, is suggested to be prolonged in reality. PMID:28787906
In-Plane Behaviour of a Reinforcement Concrete Frame with a Dry Stack Masonry Panel.
Lin, Kun; Totoev, Yuri Zarevich; Liu, Hongjun; Guo, Tianyou
2016-02-11
In order to improve the energy dissipation of the masonry infilled frame structure while decreasing the stiffening and strengthening effects of the infill panels, a new dry stacked panel (DSP) semi-interlocking masonry (SIM) infill panel has been developed. In this paper, the material properties of DSP and a traditional unreinforced masonry (URM) panel have been evaluated experimentally. A series of cyclic tests were performed to investigate the cyclic behaviour of the reinforcement concrete (RC) frame with different infill panels. The failure modes, damage evolution, hysteretic behaviour, stiffness degradation and energy dissipation were compared and analysed. We concluded that DSP is capable of significantly improving the seismic energy dissipation due to its hysteretic behaviour when the frame is in elastic stage without increasing the stiffness of the frame. Therefore, DSP or SIM panels can be considered as frictional dampers. Based on the experimental results, the influence of DSP was examined. Using the parallel model, the hysteretic loops of DSP subjected to different load cases were achieved. The typical full hysteretic loop for DSP could be divided into three distinct stages of behaviour: packing stage, constant friction stage and equivalent strut stage. The connection between the panel and the frame had a great effect on the transferring of different mechanical stages. The constant friction stage was verified to provide substantial energy dissipation and benefits to the ductility of the structure, which, therefore, is suggested to be prolonged in reality.
Winston, Ryan J; Al-Rubaei, Ahmed M; Blecken, Godecke T; Viklander, Maria; Hunt, William F
2016-03-15
The surface infiltration rates (SIR) of permeable pavements decline with time as sediment and debris clog pore spaces. Effective maintenance techniques are needed to ensure the hydraulic functionality and water quality benefits of this stormwater control. Eight different small-scale and full-scale maintenance techniques aimed at recovering pavement permeability were evaluated at ten different permeable pavement sites in the USA and Sweden. Maintenance techniques included manual removal of the upper 2 cm of fill material, mechanical street sweeping, regenerative-air street sweeping, vacuum street sweeping, hand-held vacuuming, high pressure washing, and milling of porous asphalt. The removal of the upper 2 cm of clogging material did not significantly improve the SIR of concrete grid paves (CGP) and permeable interlocking concrete pavers (PICP) due to the inclusion of fines in the joint and bedding stone during construction, suggesting routine maintenance cannot overcome improper construction. For porous asphalt maintenance, industrial hand-held vacuum cleaning, pressure washing, and milling were increasingly successful at recovering the SIR. Milling to a depth of 2.5 cm nearly restored the SIR for a 21-year old porous asphalt pavement to like-new conditions. For PICP, street sweepers employing suction were shown to be preferable to mechanical sweepers; additionally, maintenance efforts may become more intensive over time to maintain a threshold SIR, as maintenance was not 100% effective at removing clogging material. Copyright © 2015 Elsevier Ltd. All rights reserved.
49 CFR 236.820 - Switch, interlocked.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, interlocked. 236.820 Section 236.820 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, interlocked. A switch within the interlocking limits the control of which is interlocked with...
49 CFR 236.820 - Switch, interlocked.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Switch, interlocked. 236.820 Section 236.820 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, interlocked. A switch within the interlocking limits the control of which is interlocked with...
49 CFR 236.820 - Switch, interlocked.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Switch, interlocked. 236.820 Section 236.820 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, interlocked. A switch within the interlocking limits the control of which is interlocked with...
49 CFR 236.820 - Switch, interlocked.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Switch, interlocked. 236.820 Section 236.820 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, interlocked. A switch within the interlocking limits the control of which is interlocked with...
49 CFR 236.820 - Switch, interlocked.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Switch, interlocked. 236.820 Section 236.820 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, interlocked. A switch within the interlocking limits the control of which is interlocked with...
Effect of geometric nonlinearity on acoustic modulation
NASA Astrophysics Data System (ADS)
Warnemuende, Kraig; Wu, Hwai-Chung
2005-05-01
Non-linear nondestructive testing is different from linear acoustic in that it correlates the presence and characteristics of a defect with acoustical signals whose frequencies differ from the frequencies of the emitted probe signal. The difference in frequencies between the probe signal and the resulting frequencies is due to a nonlinear transformation of the probe signal as it passes through a defect. Under acoustic interrogation due to longitudinal waves, as the compression phase passes the defect the two sides of the interface are in direct contact and the contact area increases. Similarly, the tensile phase passes through the defect, the two sides separate and the contact area decreases, thereby modulating the signal amplitude. The contact area depends on the roughness of the surface and on the magnitude of the cohesive forces that arise from the small crack openings. Such cohesive forces may be attributed to aggregate interlock (in plain concrete), fiber bridging (in fiber reinforced concrete) or both. In this paper, the frequency shifts of the probe elastic wave will be analytically related to the roughness and varying cohesive forces of the crack-like defect.
2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING ...
2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING BUILDING, AND POWER SUBSTATION - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD
Interlock system for machine protection of the KOMAC 100-MeV proton linac
NASA Astrophysics Data System (ADS)
Song, Young-Gi
2015-02-01
The 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC) has been developed. The beam service started this year after performing the beam commissioning. If the very sensitive and essential equipment is to be protected during machine operation, a machine interlock system is required, and the interlock system has been implemented. The purpose of the interlock system is to shut off the beam when the radio-frequency (RF) and ion source are unstable or a beam loss occurs. The interlock signal of the KOMAC linac includes a variety of sources, such as the beam loss, RF and high-voltage converter modulator faults, and fast closing valves of the vacuum window at the beam lines and so on. This system consists of a hardware-based interlock system using analog circuits and a software-based interlock system using an industrial programmable logic controller (PLC). The hardware-based interlock system has been fabricated, and the requirement has been satisfied with the results being within 10 µs. The software logic interlock system using the PLC has been connected to the framework of with the experimental physics and industrial control system (EPICS) to integrate a variety of interlock signals and to control the machine components when an interlock occurs. This paper will describe the design and the construction of the machine interlock system for the KOMAC 100-MeV linac.
Downs, Jonathan; Shults, Ruth; West, Bethany
2017-12-01
Ignition interlocks are effective in reducing alcohol-impaired driving recidivism for all offenders, including first-time offenders. Despite their effectiveness, interlock use among persons convicted of driving while intoxicated from alcohol (DWI) remains low. This cross-sectional survey of U.S. adults assessed public support for requiring ignition interlocks for all convicted DWI offenders including first-time offenders. The goal was to update results from a similar 2010 survey in light of new state requirements and increased interlock installations. Questions were included in the Porter Novelli FallStyles survey, which was fielded from September 28 to October 16, 2015. Participants were the 3,536 individuals who provided an opinion toward requiring ignition interlocks for all offenders. For analyses, opinion toward requiring interlocks for all offenders was dichotomized into 'agree' and 'neutral/disagree.' To handle missing data, 10 imputed datasets were created and pooled using fully conditional specification (FCS). Fifty-nine percent of adults supported requiring interlocks for all DWI offenders. Multivariate analysis revealed that persons who did not report alcohol-impaired driving (AID) were 60% more likely to support requiring interlocks than those who reported AID. Having heard of interlocks also increased support. Support was generally consistent across demographic subgroups. Interlocks for all offenders have majority support nationwide in the current survey, consistent with previous reports. Support is lowest among those who have reported alcohol-impaired driving in the past 30days. These results suggest that communities with higher levels of alcohol-impaired driving may be more resistant to requiring ignition interlocks for all convicted DWI offenders. Future studies should examine this association further. Practical applications: These results indicate that the majority of adults recognize DWI as a problem and support requiring interlocks for all offenders. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.
49 CFR 236.807 - Signal, interlocking.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, interlocking. 236.807 Section 236.807..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.807 Signal, interlocking. A roadway signal which governs movements into or within interlocking limits. ...
49 CFR 236.807 - Signal, interlocking.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Signal, interlocking. 236.807 Section 236.807..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.807 Signal, interlocking. A roadway signal which governs movements into or within interlocking limits. ...
49 CFR 236.807 - Signal, interlocking.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Signal, interlocking. 236.807 Section 236.807..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.807 Signal, interlocking. A roadway signal which governs movements into or within interlocking limits. ...
49 CFR 236.807 - Signal, interlocking.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Signal, interlocking. 236.807 Section 236.807..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.807 Signal, interlocking. A roadway signal which governs movements into or within interlocking limits. ...
49 CFR 236.807 - Signal, interlocking.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Signal, interlocking. 236.807 Section 236.807..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.807 Signal, interlocking. A roadway signal which governs movements into or within interlocking limits. ...
21 CFR 876.4590 - Interlocking urethral sound.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...
21 CFR 876.4590 - Interlocking urethral sound.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...
21 CFR 876.4590 - Interlocking urethral sound.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...
21 CFR 876.4590 - Interlocking urethral sound.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...
21 CFR 876.4590 - Interlocking urethral sound.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...
FRICTION STIR LAP WELDING OF ALUMINUM - POLYMER USING SCRIBE TECHNOLOGY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Upadhyay, Piyush; Hovanski, Yuri; Fifield, Leonard S.
2015-02-16
Friction Stir Scribe (FSS) technology is a relatively new variant of Friction Stir Welding (FSW) which enables lap joining of dissimilar material with very different melting points and different high temperature flow behaviors. The cutter scribe attached at the tip of FSW tool pin effectively cuts the high melting point material such that a mechanically interlocking feature is created between the dissimilar materials. The geometric shape of this interlocking feature determines the shear strength attained by the lap joint. This work presents first use of scribe technology in joining polymers to aluminum alloy. Details of the several runs of scribemore » welding performed in lap joining of ~3.175mm thick polymers including HDPE, filled and unfilled Nylon 66 to 2mm thick AA5182 are presented. The effect of scribe geometry and length on weld interlocking features is presented along with lap shear strength evaluations.« less
Replacement of Fine Aggregate by using Recyclable Materials in Paving Blocks
NASA Astrophysics Data System (ADS)
Koganti, Shyam Prakash; Hemanthraja, Kommineni; Sajja, Satish
2017-08-01
Cement concrete paving blocks are precast hard products complete out of cement concrete. The product is made in various sizes and shapes like square, round and rectangular blocks of different dimensions with designs for interlocking of adjacent tiles blocks. Several Research Works have been carried out in the past to study the possibility of utilizing waste materials and industrial byproducts in the manufacturing of paver blocks. Various industrial waste materials like quarry dust, glass powder, ceramic dust and coal dust are used as partial replacement of fine aggregate and assessed the strength parameters and compared the profit percentages after replacement with waste materials. Quarry dust can be replaced by 20% and beyond that the difference in strength is not much higher but considering cost we can replace upto 40% so that we can get a profit of almost 10%. Similarly we can replace glass powder and ceramic dust by 20% only beyond that there is decrement in strength and even with 20% replacement we can get 1.34 % and 2.42% of profit. Coal dust is not suitable for alternative material as fine aggregate as it reduces the strength.
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of signal...
49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of signal...
12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Interlocking relationships between bank and its... Section 32 of the Glass-Steagall Act § 250.410 Interlocking relationships between bank and its commingled... Banking Act of 1933 in view of the interlocking relationships that would exist between the bank and...
12 CFR 303.249 - Management official interlocks.
Code of Federal Regulations, 2012 CFR
2012-01-01
... interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Management official interlocks. 303.249 Section...
12 CFR 303.249 - Management official interlocks.
Code of Federal Regulations, 2013 CFR
2013-01-01
... interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Management official interlocks. 303.249 Section...
12 CFR 303.249 - Management official interlocks.
Code of Federal Regulations, 2011 CFR
2011-01-01
... interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Management official interlocks. 303.249 Section...
12 CFR 303.249 - Management official interlocks.
Code of Federal Regulations, 2010 CFR
2010-01-01
... interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Management official interlocks. 303.249 Section...
12 CFR 303.249 - Management official interlocks.
Code of Federal Regulations, 2014 CFR
2014-01-01
... interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Management official interlocks. 303.249 Section...
12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Interlocking relationships between bank and its... Interpretations of Section 32 of the Glass-Steagall Act § 250.410 Interlocking relationships between bank and its... section 32 of the Banking Act of 1933 in view of the interlocking relationships that would exist between...
12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Interlocking relationships between bank and its... Section 32 of the Glass-Steagall Act § 250.410 Interlocking relationships between bank and its commingled... Banking Act of 1933 in view of the interlocking relationships that would exist between the bank and...
12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Interlocking relationships between bank and its... Interpretations of Section 32 of the Glass-Steagall Act § 250.410 Interlocking relationships between bank and its... section 32 of the Banking Act of 1933 in view of the interlocking relationships that would exist between...
12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Interlocking relationships between bank and its... Interpretations of Section 32 of the Glass-Steagall Act § 250.410 Interlocking relationships between bank and its... section 32 of the Banking Act of 1933 in view of the interlocking relationships that would exist between...
Fan, Ke-Jie; Chen, Ke; Ma, Wen-Long; Tian, Ke-Wei; Ye, Ye; Chen, Hong-Gan; Tang, Yan-Feng; Cai, Hong-Min
2018-05-25
To investigate the effect of minimally invasive mini-incision and instrumented reduction combined with interlocking intramedullary nailing in the treatment of patients with multi-segment fracture of complex femoral shaft. From January 2013 to January 2016, 32 patients with multiple fractures segments of femoral shaft were treated with instrumentation-assisted reduction combined with interlocking intramedullary nailing, including 22 males and 10 females with an average age of 45 years old ranging 17 to 68 years old. The time from injured to operation was 5 to 10 days with an average of 7 days. After admission, routine tibial tubercle or supracondylar bone traction was performed. The patient's general condition was evaluated, the operation time and intraoperative blood loss were recorded. According to Thorsen femoral fracture morphology evaluation criteria and Hohl knee function evaluation of postoperative efficacy, postoperative fracture healing, complications and postoperative recovery of limb function were observed. All patients were followed up for 6 to 24 months with an average of 12 months. The operative time ranged from 48 to 76 minutes with an average of 67 min. The intraoperative blood loss was 150 to 400 ml with an average of 220 ml. The surgical incisions all achieved grade A healing. The fractures reached the clinical standard of healing. The fracture healing time ranged from 4.2 to 10.8 months with an average of 5.7 months. There were no nonunion, incision infection and internal fixation fracture, failure and other complications. According to Thorsen femoral fracture morphology evaluation criteria, the result was excellent in 28 cases, good in 3 cases, fair in 1 case. According to Hohl knee function evaluation criteria, the result was excellent in 30 cases, good in 2 cases. Instrument-assisted reduction combined with interlocking intramedullary nail fixation is a safe and effective method for the treatment of complex femoral shaft fractures. It has advantages of small trauma, fixed fixation, quick recovery, early postoperative functional exercise. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.
Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru
2005-02-08
An advanced containment system for containing buried waste and associated leachate. The advanced containment system comprises a plurality of casing sections with each casing section interlocked to an adjacent casing section. Each casing section includes a complementary interlocking structure that interlocks with the complementary interlocking structure on an adjacent casing section. A barrier filler substantially fills the casing sections and may substantially fill the spaces of the complementary interlocking structure to form a substantially impermeable barrier. Some of the casing sections may include sensors so that the casing sections and the zone of interest may be remotely monitored after the casing sections are emplaced in the ground.
Coastal protection using topological interlocking blocks
NASA Astrophysics Data System (ADS)
Pasternak, Elena; Dyskin, Arcady; Pattiaratchi, Charitha; Pelinovsky, Efim
2013-04-01
The coastal protection systems mainly rely on the self-weight of armour blocks to ensure its stability. We propose a system of interlocking armour blocks, which form plate-shape assemblies. The shape and the position of the blocks are chosen in such a way as to impose kinematic constraints that prevent the blocks from being removed from the assembly. The topological interlocking shapes include simple convex blocks such as platonic solids, the most practical being tetrahedra, cubes and octahedra. Another class of topological interlocking blocks is so-called osteomorphic blocks, which form plate-like assemblies tolerant to random block removal (almost 25% of blocks need to be removed for the assembly to loose integrity). Both classes require peripheral constraint, which can be provided either by the weight of the blocks or post-tensioned internal cables. The interlocking assemblies provide increased stability because lifting one block involves lifting (and bending) the whole assembly. We model the effect of interlocking by introducing an equivalent additional self-weight of the armour blocks. This additional self-weight is proportional to the critical pressure needed to cause bending of the interlocking assembly when it loses stability. Using beam approximation we find an equivalent stability coefficient for interlocking. It is found to be greater than the stability coefficient of a structure with similar blocks without interlocking. In the case when the peripheral constraint is provided by the weight of the blocks and for the slope angle of 45o, the effective stability coefficient for a structure of 100 blocks is 33% higher than the one for a similar structure without interlocking. Further increase in the stability coefficient can be reached by a specially constructed peripheral constraint system, for instance by using post-tension cables.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Qi; Yu, Chao; Long, Hai
2015-05-08
Highly stable permanently interlocked aryleneethynylene molecular cages were synthesized from simple triyne monomers using dynamic alkyne metathesis. The interlocked complexes are predominantly formed in the reaction solution in the absence of any recognition motif and were isolated in a pure form using column chromatography. This study is the first example of the thermodynamically controlled solution-phase synthesis of interlocked organic cages with high stability.
Method of installing subsurface barrier
Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.
2007-10-09
Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.
Subsurface materials management and containment system
Nickelson, Reva A.; Richardson, John G.; Kosteinik, Kevin M.; Sloan, Paul A.
2004-07-06
Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.
Subsurface materials management and containment system
Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.
2006-10-17
Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.
Weninger, Patrick; Schueller, Michael; Jamek, Michael; Stanzl-Tschegg, Stefanie; Redl, Heinz; Tschegg, Elmar K
2009-05-01
Unreamed tibia nails with small diameters are increasingly used for fracture fixation. However, little is known about the fatigue strength of proximal and distal interlocking screws in those nails. To date, no data are available reporting on mechanical differences of solid compared to cannulated tibial nails. The aim of this study was to assess the fatigue strength of proximal and distal interlocking screws of solid and cannulated small diameter tibia nails. We created a distal tibia fracture model (AO/OTA 43 A3) using 16 Sawbones. After fracture stabilization with one of four different nail types (Expert Tibial Nail, VersaNail, T2 Tibial Nailing System, Connex), mechanical testing was performed in three loading series (40,000 cycles each) with incremental loads. Timing and type of interlocking screw failure were assessed. Interlocking screw failure was observed significantly earlier (after a mean interval of 57,042 cycles) in cannulated tibial nails (VersaNail, T2) compared to solid nails (after a mean interval of 88,415 cycles; P < 0.001). Proximal interlocking screw failure was recorded if oblique screws were used proximally (VersaNail, T2, Connex). No distal interlocking screw failure was recorded in the Connex nail. Two- and three-part fractures of proximal or distal interlocking screws were observed in all specimen. Proximal and distal interlocking screw failure has to be considered in small diameter nails in case of delayed fracture healing. To support our results, further experimental studies and clinical series are necessary.
8. VIEW, LOOKING NORTH, OF INTERLOCKING MACHINE WITH ORIGINAL MODEL ...
8. VIEW, LOOKING NORTH, OF INTERLOCKING MACHINE WITH ORIGINAL MODEL BOARD IN CENTER AND MODEL SEMAPHORE SIGNALS (AT TOP OF PHOTOGRAPH), THIRD FLOOR - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA
Temporal evolution modeling of hydraulic and water quality performance of permeable pavements
NASA Astrophysics Data System (ADS)
Huang, Jian; He, Jianxun; Valeo, Caterina; Chu, Angus
2016-02-01
A mathematical model for predicting hydraulic and water quality performance in both the short- and long-term is proposed based on field measurements for three types of permeable pavements: porous asphalt (PA), porous concrete (PC), and permeable inter-locking concrete pavers (PICP). The model was applied to three field-scale test sites in Calgary, Alberta, Canada. The model performance was assessed in terms of hydraulic parameters including time to peak, peak flow and water balance and a water quality variable (the removal rate of total suspended solids). A total of 20 simulated storm events were used for model calibration and verification processes. The proposed model can simulate the outflow hydrographs with a coefficient of determination (R2) ranging from 0.762 to 0.907, and normalized root-mean-square deviation (NRMSD) ranging from 13.78% to 17.83%. Comparison of the time to peak flow, peak flow, runoff volume and TSS removal rates between the measured and modeled values in model verification phase had a maximum difference of 11%. The results demonstrate that the proposed model is capable of capturing the temporal dynamics of the pavement performance. Therefore, the model has great potential as a practical modeling tool for permeable pavement design and performance assessment.
Permeable pavement study (Edison)
While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable interlocking concrete pavement (PICP), pervious concrete (PC), and porous asphalt (PA). Each permeable pavement type has four, 54.9-m2, lined sections that direct all infiltrate into 5.7-m3 tanks enabling complete volume collection and sampling. This paper highlights the results from a 12-month period when samples were collected from 13 rainfall/runoff events and analyzed for nitrogen species, orthophosphate, and organic carbon. Differences in infiltrate concentrations among the three permeable pavement types were assessed and compared with concentrations in rainwater samples and impervious asphalt runoff samples, which were collected as controls. Contrary to expectations based on the literature, the PA infiltrate had significantly larger total nitrogen (TN) concentrations than runoff and infiltrate from the other two permeable pavement types, indicating that nitrogen leached from materials in the PA strata. There was no significant difference in TN concentration between runoff and infiltrate from either PICP or PC, but TN in runoff was significantly larger than in the rainwater, suggesting meaningful inter-event dry de
Detection of semi-volatile organic compounds in permeable ...
Abstract The Edison Environmental Center (EEC) has a research and demonstration permeable parking lot comprised of three different permeable systems: permeable asphalt, porous concrete and interlocking concrete permeable pavers. Water quality and quantity analysis has been ongoing since January, 2010. This paper describes a subset of the water quality analysis, analysis of semivolatile organic compounds (SVOCs) to determine if hydrocarbons were in water infiltrated through the permeable surfaces. SVOCs were analyzed in samples collected from 11 dates over a 3 year period, from 2/8/2010 to 4/1/2013.Results are broadly divided into three categories: 42 chemicals were never detected; 12 chemicals (11 chemical test) were detected at a rate of less than 10% or less; and 22 chemicals were detected at a frequency of 10% or greater (ranging from 10% to 66.5% detections). Fundamental and exploratory statistical analyses were performed on these latter analyses results by grouping results by surface type. The statistical analyses were limited due to low frequency of detections and dilutions of samples which impacted detection limits. The infiltrate data through three permeable surfaces were analyzed as non-parametric data by the Kaplan-Meier estimation method for fundamental statistics; there were some statistically observable difference in concentration between pavement types when using Tarone-Ware Comparison Hypothesis Test. Additionally Spearman Rank order non-parame
Update to Permeable Pavement Research at the Edison ...
The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, pervious concrete, and porous asphalt. The permeable pavements are limited to parking spaces while adjacent driving lanes are impermeable and drain to the permeable surfaces. The parking lot is instrumented for continuous monitoring with thermistors and water content reflectometers that measure moisture as infiltrate passes through the storage gallery beneath the permeable pavements into the underlying native soil. Each permeable surface of the parking lot has four lined sections that capture infiltrate in tanks for water quality analyses; these tanks are capable of holding volumes up to 4.1 m3, which represents up to 38 mm (1.5 in.) for direct rainfall on the porous pavement and runoff from adjacent driving lanes that drain into the permeable surface.Previous technical releases concerning the demonstration site focused on monitoring techniques, observed chloride and nutrient concentrations, surface hydrology, and infiltration and evaporation rates. This presentation summarizes these past findings and addresses current water quality efforts including pH, solids analysis, total organic carbon, and chemical oxygen demand. Stormwater runoff continues to be a major cause of water pollution in
Zhu, Hai-Bing; Wu, Li-Guo; Fang, Zhi-Song; Luo, Cong-Feng; Wang, Qing-Feng; Ma, Yi-Ping; Gao, Hong; Fu, Guo-Hai; Hu, Cheng-Ting
2012-07-01
To introduce the clinical method of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nails. From June 2006 to March 2011, 26 patients with distal tibial fracture were treated with interlocking intramedullary nails using blocking screws and rooting technique, included 18 males and 8 females with an average age of 46.2 years old ranging from 24 to 64 years. According to AO classification: 10 cases of type A1, 4 cases of type A2, 8 cases of type B1, 4 cases of type B2. The average distance of the fractures end to the ankle joint was 85 mm ranging from 55 to 125 mm, the mean time between injured and operation was 4.5 days. The patients were evaluated with pain, range of motion, walking. All cases were followed-up for 6 to 22 months (averaged 15 months). According to Iowa ankle joint grading system,the score was improved from preoperative (66.8 +/- 8.2) to postoperative (94.6 +/- 4.8). All fractures had united, and got satisfactory reduction and stable fixation with no complications had happen such as breakage of screw. Fixation with interlocking intramedullary nail using blocking screws and rooting technique in treating distal tibial fracture, is a safe and effective technique for the improvement of stability.
Method of sealing casings of subsurface materials management system
Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.
2007-02-06
Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.
Analysis of interlocking performances on non-oriented electrical steels
NASA Astrophysics Data System (ADS)
Liu, Li-Hsiang; Liu, Lee-Cheng
2018-05-01
In order to reduce energy loss in motor, applications of high-efficiency non-oriented electrical steel sheets and optimal laminating process are both important elements. The motor core loss deterioration is influenced by a number of factors, such as flux distribution, stress and strain, space harmonics, temperature, and short circuits between lamination. In conventional clamping method, steel sheets are laminated via interlocking or welding in general manner. The measured energy loss by welding was much larger than that by interlocking. Therefore, interlocking is well known and usually employed with benefit of easy conducting. The protuberance shapes affected the fastening strength. Generally, the intensity of rectangular type is stronger than the circular counterparts. However, the circular interlocking has better magnetic characteristics. To clarify the method effectiveness, interlocking performances regarding fastened strength and magnetic deterioration by lamination were investigated. The key parameters of protuberance shape and forming depth were designed. Precisely manufacturing operation was applied to avoid interlocking failure. Magnetic properties largely influenced by clamping method are crucial to minimizing the magnetic deterioration during laminating procedure. Several experiments for various processing conditions were undertaken, and the quantification results showed the rectangular interlocking had better fastened strength but worsened iron loss comparing with the circular arrangement. To acquire the comprehensive mechanical and electrical identities for electrical steel lamination, deliberate producing conditions regarding minimizing the magnetic deterioration should be adopted prudently.
1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER ...
1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER SUBSTATIONS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD
49 CFR 236.772 - Machine, interlocking.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Machine, interlocking. An assemblage of manually operated levers or other devices for the control of...
49 CFR 236.772 - Machine, interlocking.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Machine, interlocking. An assemblage of manually operated levers or other devices for the control of...
Impact of State Ignition Interlock Laws on Alcohol-Involved Crash Deaths in the United States.
Kaufman, Elinore J; Wiebe, Douglas J
2016-05-01
To investigate the impact on alcohol-involved crash deaths of universal ignition interlock requirements, which aim to prevent people convicted of driving under the influence of alcohol from driving while intoxicated. We used data from the National Highway Traffic Safety Administration for 1999 to 2013. From 2004 to 2013, 18 states made interlocks mandatory for all drunk-driving convictions. We compared alcohol-involved crash deaths between 18 states with and 32 states without universal interlock requirements, accounting for state and year effects, and for clustering within states. Policy impact was apparent 3 years after implementation. The adjusted rate of alcohol-involved crash deaths was 4.7 (95% confidence interval [CI] = 4.0, 5.4) per 100,000 in states with the universal interlock requirement, compared with 5.5 (95% CI = 5.48, 5.53) in states without, an absolute reduction of 0.8 (95% CI = 0.1, 1.5) deaths per 100,000 per year. Requiring ignition interlocks for all drunk-driving convictions was associated with 15% fewer alcohol-involved crash deaths, compared with states with less-stringent requirements. Interlocks are a life-saving technology that merit wider use.
9. VIEW, LOOKING SOUTH, OF INTERLOCKING MACHINE, WITH ORIGINAL MODEL ...
9. VIEW, LOOKING SOUTH, OF INTERLOCKING MACHINE, WITH ORIGINAL MODEL BOARD IN CENTER, NEW MODEL BOARD AT LEFT AND MODEL SEMAPHORES AT TOP OF PHOTOGRAPH, THIRD FLOOR - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA
Ignition interlocks reduce re-arrest rates of alcohol offenders
DOT National Transportation Integrated Search
2000-01-15
In a recent study of repeat offenders in Maryland, ignition interlocks reduced the risk of alcohol traffic violations by 64% during the first year they were required. In the second year, when interlocks could be removed, 3.5% of the remaining interlo...
Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.
2006-04-18
Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.
The effects of closer monitoring on driver compliance with interlock restrictions.
Zador, Paul L; Ahlin, Eileen M; Rauch, William J; Howard, Jan M; Duncan, G Doug
2011-11-01
This randomized controlled trial of 2168 DWI multiple offenders assigned to a state-wide ignition interlock program in Maryland compared non-compliance with interlock requirements among drivers who were closely monitored (by Westat staff) and drivers who received standard monitoring (by the Motor Vehicle Administration). Compliance comparisons relied on datalogger data from MVA's interlock providers plus driver records that contained demographic information, prior alcohol-related traffic violations, their dispositions, and interlock duration. Measures for quantifying non-compliance included rates per 1000 engine starts for initial breath test failures at varying BAC levels and time periods, retest failures, retest refusals, interlock disconnects, startup violations, and summation measures. Regression analysis estimated the effects of closer monitoring on non-compliance, using linear mixed models that included random driver effects and fixed effects for study-group assignment, prior alcohol-related traffic violations, and months of continuous datalogger data with a quadratic function that assessed changes and rates of change in interlock non-compliance over time. All the separate non-compliance rates and summary measures derived from them were lower for closer monitored than control drivers for continuous data series of at least 6, 12, or 24 months. The differences for initial test failures and the two summary measures were statistically significant. Most measures of non-compliance decreased significantly as continuous time on the interlock increased. Parallel trends in each study group indicated that drivers learned to improve their compliance over time. Thus, this study convincingly demonstrates that closer monitoring substantially enhanced compliance with requirements of the ignition interlock and that regardless of group assignment, compliance increased over time. Copyright © 2011 Elsevier Ltd. All rights reserved.
Otter, Carl A; Patty, Philipus J; Williams, Martin A K; Waterland, Mark R; Telfer, Shane G
2011-03-01
We have employed the toolbox of metallosupramolecular chemistry to mechanically interlock gold and silver nanoparticles. A specifically designed PEGthiol-functionalized bis(phenanthroline)copper(I) complex acts to 'catenate' the nanoparticles. The interlocked assemblies were characterised by three complementary techniques: DLS, SERS and TEM.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Electromechanical interlocking machine; locking between electrical and mechanical levers. 236.340 Section 236.340 Transportation Other Regulations... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Electromechanical interlocking machine; locking between electrical and mechanical levers. 236.340 Section 236.340 Transportation Other Regulations... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Electromechanical interlocking machine; locking between electrical and mechanical levers. 236.340 Section 236.340 Transportation Other Regulations... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Electromechanical interlocking machine; locking between electrical and mechanical levers. 236.340 Section 236.340 Transportation Other Regulations... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical...
Code of Federal Regulations, 2010 CFR
2010-10-01
... between electrical and mechanical levers. 236.340 Section 236.340 Transportation Other Regulations... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that mechanical...
Enhancing the Use of Vehicle Alcohol Interlocks With Emerging Technology.
Voas, Robert B
2014-01-01
Among the earliest applications of health technologies to a safety program was the development of blood alcohol content (BAC) tests for use in impaired-driving enforcement. This led to the development of miniature, highly accurate devices that officers could carry in their pockets. A natural extension of this technology was the vehicle alcohol interlock, which is used to reduce recidivism among drivers convicted of driving under the influence (DUI) by requiring them to install the devices (which will not allow someone with a positive BAC to drive) on their vehicles. While on the vehicle, interlocks have been shown to reduce recidivism by two-thirds. Use of these devices has been growing at the rate of 10 to 15 percent a year, and there currently are more than 300,000 units in use. This expansion in the application of interlocks has benefited from the integration of other emerging technologies into interlock systems. Such technologies include data systems that record both driver actions and vehicle responses, miniature cameras and face recognition to identify the user, Wi-Fi systems to provide rapid reporting on offender performance and any attempt to circumvent the device, GPS tracking of the vehicle, and more rapid means for monitoring the integrity of the interlock system. This article describes how these health technologies are being applied in interlock programs and the outlook for new technologies and new court sanctioning programs that may influence the growth in the use of interlocks in the future.
30 CFR 18.41 - Plug and receptacle-type connectors.
Code of Federal Regulations, 2014 CFR
2014-07-01
... electrically interlocked with an automatic circuit-interrupting device. (i) Mechanically interlocked connectors... shall be removed before the plug can be withdrawn and the electrical energy in the interlocking pilot.... (d) Molded-elastomer connectors will be acceptable provided: (1) Any free space within the plug or...
30 CFR 18.41 - Plug and receptacle-type connectors.
Code of Federal Regulations, 2010 CFR
2010-07-01
... electrically interlocked with an automatic circuit-interrupting device. (i) Mechanically interlocked connectors... shall be removed before the plug can be withdrawn and the electrical energy in the interlocking pilot.... (d) Molded-elastomer connectors will be acceptable provided: (1) Any free space within the plug or...
30 CFR 18.41 - Plug and receptacle-type connectors.
Code of Federal Regulations, 2013 CFR
2013-07-01
... electrically interlocked with an automatic circuit-interrupting device. (i) Mechanically interlocked connectors... shall be removed before the plug can be withdrawn and the electrical energy in the interlocking pilot.... (d) Molded-elastomer connectors will be acceptable provided: (1) Any free space within the plug or...
30 CFR 18.41 - Plug and receptacle-type connectors.
Code of Federal Regulations, 2012 CFR
2012-07-01
... electrically interlocked with an automatic circuit-interrupting device. (i) Mechanically interlocked connectors... shall be removed before the plug can be withdrawn and the electrical energy in the interlocking pilot.... (d) Molded-elastomer connectors will be acceptable provided: (1) Any free space within the plug or...
30 CFR 18.41 - Plug and receptacle-type connectors.
Code of Federal Regulations, 2011 CFR
2011-07-01
... electrically interlocked with an automatic circuit-interrupting device. (i) Mechanically interlocked connectors... shall be removed before the plug can be withdrawn and the electrical energy in the interlocking pilot.... (d) Molded-elastomer connectors will be acceptable provided: (1) Any free space within the plug or...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-30
... credit unions. The Interlocks Act generally prohibits financial institution management officials from... federally insured credit unions having a common management official with another type financial institution... comply with the Depository Institution Management Interlocks Act (Interlocks Act) and to determine...
46 CFR 111.91-1 - Power, control, and interlock circuits.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 111.91-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters § 111.91-1 Power, control, and interlock circuits. Each electric power, control, and interlock circuit of an elevator or dumbwaiter must meet ASME...
46 CFR 111.91-1 - Power, control, and interlock circuits.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 111.91-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters § 111.91-1 Power, control, and interlock circuits. Each electric power, control, and interlock circuit of an elevator or dumbwaiter must meet ASME...
46 CFR 111.91-1 - Power, control, and interlock circuits.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 111.91-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters § 111.91-1 Power, control, and interlock circuits. Each electric power, control, and interlock circuit of an elevator or dumbwaiter must meet ASME...
46 CFR 111.91-1 - Power, control, and interlock circuits.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 111.91-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters § 111.91-1 Power, control, and interlock circuits. Each electric power, control, and interlock circuit of an elevator or dumbwaiter must meet ASME...
46 CFR 111.91-1 - Power, control, and interlock circuits.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 111.91-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters § 111.91-1 Power, control, and interlock circuits. Each electric power, control, and interlock circuit of an elevator or dumbwaiter must meet ASME...
30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Motor-starter enclosures; barriers and...-Voltage Distribution High-Voltage Longwalls § 75.819 Motor-starter enclosures; barriers and interlocks. Compartment separation and cover interlock switches for motor-starter enclosures must be maintained in...
Code of Federal Regulations, 2014 CFR
2014-10-01
... drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). 1242.58 Section 1242.58... Operating signals and interlockers, operating drawbridges, highway crossing protection (accounts XX-51-59..., interlockers, drawbridges and highway crossings are located. ...
Code of Federal Regulations, 2011 CFR
2011-10-01
... drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). 1242.58 Section 1242.58... Operating signals and interlockers, operating drawbridges, highway crossing protection (accounts XX-51-59..., interlockers, drawbridges and highway crossings are located. ...
Code of Federal Regulations, 2012 CFR
2012-10-01
... drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). 1242.58 Section 1242.58... Operating signals and interlockers, operating drawbridges, highway crossing protection (accounts XX-51-59..., interlockers, drawbridges and highway crossings are located. ...
Code of Federal Regulations, 2013 CFR
2013-10-01
... drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). 1242.58 Section 1242.58... Operating signals and interlockers, operating drawbridges, highway crossing protection (accounts XX-51-59..., interlockers, drawbridges and highway crossings are located. ...
Evaluation of recycled concrete as aggregate in new concrete pavements.
DOT National Transportation Integrated Search
2014-04-01
This study evaluated the use of recycled concrete as coarse aggregate in new concrete pavements. : Recycled concrete aggregate (RCA) produced from demolished pavements in three geographically dispersed locations in Washington state were used to perfo...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations... block signal system and interlocking standards applicable to traffic control systems. The standards...
Interlocking oil: big oil ties with other corporations
DOE Office of Scientific and Technical Information (OSTI.GOV)
McDonald, A.; Fritsch, A.J.
1974-01-01
There are 460 interlocking directorates and advisory committee connections of eighteen large oil companies with well-known large corporations. There are 132 interlocks with banks; 31 with insurance; 12 with utility companies; 15 with transportation corporations; 46 affiliations with educational institutions; and 224 with manufacturing and distribution corporations. (MCW)
18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.
Code of Federal Regulations, 2013 CFR
2013-04-01
... FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY APPROVED FORMS, FEDERAL POWER ACT AND PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 FORMS § 131.31 FERC Form No. 561, Annual report of interlocking... the Federal Energy Regulatory Commission's staff for the review and oversight of interlocking...
18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.
Code of Federal Regulations, 2012 CFR
2012-04-01
... FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY APPROVED FORMS, FEDERAL POWER ACT AND PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 FORMS § 131.31 FERC Form No. 561, Annual report of interlocking... the Federal Energy Regulatory Commission's staff for the review and oversight of interlocking...
18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.
Code of Federal Regulations, 2014 CFR
2014-04-01
... FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY APPROVED FORMS, FEDERAL POWER ACT AND PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 FORMS § 131.31 FERC Form No. 561, Annual report of interlocking... the Federal Energy Regulatory Commission's staff for the review and oversight of interlocking...
18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.
Code of Federal Regulations, 2011 CFR
2011-04-01
... FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY APPROVED FORMS, FEDERAL POWER ACT AND PUBLIC UTILITY REGULATORY POLICIES ACT OF 1978 FORMS § 131.31 FERC Form No. 561, Annual report of interlocking... the Federal Energy Regulatory Commission's staff for the review and oversight of interlocking...
Impact of State Ignition Interlock Laws on Alcohol-Involved Crash Deaths in the United States
Wiebe, Douglas J.
2016-01-01
Objectives. To investigate the impact on alcohol-involved crash deaths of universal ignition interlock requirements, which aim to prevent people convicted of driving under the influence of alcohol from driving while intoxicated. Methods. We used data from the National Highway Traffic Safety Administration for 1999 to 2013. From 2004 to 2013, 18 states made interlocks mandatory for all drunk-driving convictions. We compared alcohol-involved crash deaths between 18 states with and 32 states without universal interlock requirements, accounting for state and year effects, and for clustering within states. Results. Policy impact was apparent 3 years after implementation. The adjusted rate of alcohol-involved crash deaths was 4.7 (95% confidence interval [CI] = 4.0, 5.4) per 100 000 in states with the universal interlock requirement, compared with 5.5 (95% CI = 5.48, 5.53) in states without, an absolute reduction of 0.8 (95% CI = 0.1, 1.5) deaths per 100 000 per year. Conclusions. Requiring ignition interlocks for all drunk-driving convictions was associated with 15% fewer alcohol-involved crash deaths, compared with states with less-stringent requirements. Interlocks are a life-saving technology that merit wider use. PMID:26985604
Roth, Richard; Marques, Paul R.; Voas, Robert B.
2009-01-01
Problem The effectiveness of ignition interlocks at reducing drunk driving has been limited by the ability of driving-while-intoxicated (DWI) offenders to avoid court orders to install the devices. Methods In a pilot program in New Mexico, four Santa Fe County judges imposed home confinement (via electronic monitoring bracelets) on offenders who claimed to have no car or no intention to drive. Interlock installation rates for Santa Fe County were compared with all other counties in New Mexico over a 2-year program and 2-year post-program period. Results During the two program years, 70% of the drivers convicted of DWI in Santa Fe County installed interlocks, compared to only 17% in the other counties, but when the program was terminated, the Santa Fe installation rate fell by 18.8 percentage points. Summary Mandating the alternative sanction of house arrest led to the highest reported interlock installation rate for DWI offenders. Impact on Industry Impaired driving is a substantial expense to employers, particularly when it bars driving that interferes with employment. Interlocks provide a method of protecting the public while permitting the offender to drive sober. This study was directed at increasing interlock use by DWI offenders. PMID:19945556
Somerson, Jeremy S; Rowley, David; Kennedy, Chad; Buttacavoli, Frank; Agarwal, Animesh
2014-07-01
To compare the time required for proximal locking screw placement between a standard freehand technique and the navigated technique, and to quantify the reduction in ionizing radiation exposure. A fresh frozen cadaver model was used for 48 proximal interlocking screw procedures. Each procedure consisted of insertion of 2 anteroposterior locking screws. Standard fluoroscopic technique was used for 24 procedures, and an electromagnetic navigation system was used for the remaining 24 procedures. Procedure duration was recorded using an electronic timer and radiation doses were documented. Mean total insertion time for both proximal interlocking screws was 405 ± 165.7 seconds with the freehand technique and 311 ± 78.3 seconds in the navigation group (P = 0.002). All procedures resulted in successful locking screw placement. Mean ionizing radiation exposure time for proximal locking was 29.5 ± 12.8 seconds. Proximal locking screw insertion using the navigation technique evaluated in this work was significantly faster than the standard fluoroscopic method. The navigated technique is effective and has the potential to prevent ionizing radiation exposure.
Evaluation of ilmenite serpentine concrete and ordinary concrete as nuclear reactor shielding
NASA Astrophysics Data System (ADS)
Abulfaraj, Waleed H.; Kamal, Salah M.
1994-07-01
The present study involves adapting a formal decision methodology to the selection of alternative nuclear reactor concretes shielding. Multiattribute utility theory is selected to accommodate decision makers' preferences. Multiattribute utility theory (MAU) is here employed to evaluate two appropriate nuclear reactor shielding concretes in terms of effectiveness to determine the optimal choice in order to meet the radiation protection regulations. These concretes are Ordinary concrete (O.C.) and Ilmenite Serpentile concrete (I.S.C.). These are normal weight concrete and heavy heat resistive concrete, respectively. The effectiveness objective of the nuclear reactor shielding is defined and structured into definite attributes and subattributes to evaluate the best alternative. Factors affecting the decision are dose received by reactor's workers, the material properties as well as cost of concrete shield. A computer program is employed to assist in performing utility analysis. Based upon data, the result shows the superiority of Ordinary concrete over Ilmenite Serpentine concrete.
High-power fiber optic cable with integrated active sensors for live process monitoring
NASA Astrophysics Data System (ADS)
Blomster, Ola; Blomqvist, Mats; Bergstrand, Hans; Pålsson, Magnus
2012-03-01
In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.
DOT National Transportation Integrated Search
1987-01-01
The report presents comparisons of initial evaluations of several concrete sealers and multiple layer polymer concrete overlays. The sealers evaluated included a solvent-dlspersed epoxy, a water-dlspersed epoxy, a silane, and a high molecular weight ...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-22
... credit unions. The Interlocks Act generally prohibits financial institution management officials from... comply with the Depository Institution Management Interlocks Act (Interlocks Act) and to determine... types of financial institutions, not between two or more credit unions. 12 U.S.C. 3204(3). NCUA last...
21. Historic view looking northeast from tracks of Shell Interlocking ...
21. Historic view looking northeast from tracks of Shell Interlocking Tower after construction, 1909. Photographic copy of photograph published in Railway Age Gazette, February 4, 1910. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY
Defining the safe current limit for opening ID photon shutter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seletskiy, S.
The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope (AIE). The beamlines (BL) and beamline frontends (FE) are designed under assumption that the electron beam is interlocked within the AIE. For historic reasons the AIS engages the ID active interlock (AI-ID) at any non-zero beam current whenever the ID photon shutter (IDPS) is getting opened. Such arrangement creates major inconveniences for BLs commissioning. Apparently theremore » is some IDPS safe current limit (SCL) under which the IDPS can be opened without interlocking the e-beam. The goal of this paper is to find such limit.« less
Communities detection as a tool to assess a reform of the Italian interlocking directorship network
NASA Astrophysics Data System (ADS)
Drago, Carlo; Ricciuti, Roberto
2017-01-01
Interlocking directorships are important communication channels among companies and may have anticompetitive effect. A corporate governance reform was introduced in 2011 to prevent interlocking directorships in the financial sector. We apply community detection techniques to the analysis of the networks in 2009 and 2012 to ascertain the effect of such reform on the Italian directorship network. We find that, although the number of interlocking directorships decreases in 2012, the reduction takes place mainly at the periphery of the network. The network core is stable, allowing the most connected companies to keep their strategic position.
McCartt, Anne T; Leaf, William A; Farmer, Charles M; Eichelberger, Angela H
2013-01-01
To examine the effects of changes to Washington State's ignition interlock laws: moving issuance of interlock orders from courts to the driver licensing department in July 2003 and extending the interlock order requirement to first-time offenders with blood alcohol concentrations (BACs) below 0.15 percent ("first simple driving under the influence [DUI]") in June 2004. Trends in conviction types, interlock installation rates, and 2-year cumulative recidivism rates were examined for first-time convictions (simple, high-BAC, test refusal DUI; deferred prosecution; alcohol-related negligent driving) stemming from DUI arrests between January 1999 and June 2006. Regression analyses examined recidivism effects of the law changes and interlock installation rates. To examine general deterrent effects, trends in single-vehicle late-night crashes in Washington were compared with trends in California and Oregon. After the 2004 law change, the proportion of simple DUIs declined somewhat, though the proportion of negligent driving convictions (no interlock order requirement) continued an upward trend. Interlock installation rates for first simple DUIs were 3 to 6 percent in the year before the law change and one third after. Recidivism declined by an estimated 12 percent (e.g., expected 10.6% without law change vs. 9.3% among offenders arrested between April and June 2006, the last study quarter) among first simple DUI offenders and an estimated 11 percent (expected 10.2% vs. 9.1%) among all first-time offenders. There was an estimated 0.06 percentage point decrease in the recidivism rate for each percentage point increase in the proportion of first simple DUI offenders with interlocks. If installation rates had been 100 vs. 34 percent for first simple DUI offenders arrested between April and June 2006, and if the linear relationship between rates of recidivism and installations continued, recidivism could have been reduced from 9.3 to 5.3 percent. With installation rates of 100 vs. 24 percent for all first offenders, their recidivism rate could have fallen from 9.1 to 3.2 percent. Although installation rates increased somewhat after the 2003 law change, recidivism rates were not significantly affected, perhaps due to the short follow-up period before the 2004 law change. The 2004 law change was associated with an 8.3 percent reduction in single-vehicle late-night crash risk. Mandating interlock orders for all first DUI convictions was associated with reductions in recidivism, even with low interlock use rates, and reductions in crashes. Additional gains are likely achievable with higher rates. Jurisdictions should seek to increase use rates and reconsider permitting reductions in DUI charges to other traffic offenses without interlock order requirements.
DOT National Transportation Integrated Search
1991-07-01
Proposed research on this project included five main objectives: 1) To test and evaluate the physical characteristics of flyash concrete in comparions to non-flyash concrete. Tests will be conducted to see if flyash concrete meets OSHD specifications...
Cyclic Behavior of Mortarless Brick Joints with Different Interlocking Shapes
Liu, Hongjun; Liu, Peng; Lin, Kun; Zhao, Sai
2016-01-01
The framed structure infilled with a mortarless brick (MB) panel exhibits considerable in-plane energy dissipation because of the relative sliding between bricks and good out-of-plane stability resulting from the use of interlocking mechanisms. The cyclic behaviors of MB are investigated experimentally in this study. Two different types of bricks, namely non-interlocking mortarless brick (N-IMB) and interlocking mortarless brick (IMB), are examined experimentally. The cyclic behavior of all of the joints (N-IMB and IMB) are investigated in consideration of the effects of interlocking shapes, loading compression stress levels and loading cycles. The hysteretic loops of N-IMB and IMB joints are obtained, according to which a mechanical model is developed. The Mohr–Coulomb failure criterion is employed to describe the shear failure modes of all of the investigated joints. A typical frictional behavior is observed for the N-IMB joints, and a significant stiffening effect is observed for the IMB joints during their sliding stage. The friction coefficients of all of the researched joints increase with the augmentation of the compression stress level and improvement of the smoothness of the interlocking surfaces. An increase in the loading cycle results in a decrease in the friction coefficients of all of the joints. The degradation rate (DR) of the friction coefficients increases with the reduction in the smoothness of the interlocking surface. PMID:28773291
Ignition Interlock Laws: Effects on Fatal Motor Vehicle Crashes, 1982-2013.
McGinty, Emma E; Tung, Gregory; Shulman-Laniel, Juliana; Hardy, Rose; Rutkow, Lainie; Frattaroli, Shannon; Vernick, Jon S
2017-04-01
Alcohol-involved motor vehicle crashes are a major cause of preventable mortality in the U.S., leading to more than 10,000 fatalities in 2013. Ignition interlocks, or alcohol-sensing devices connected to a vehicle's ignition to prevent it from starting if a driver has a predetermined blood alcohol content (BAC) level, are a promising avenue for preventing alcohol-involved driving. This study sought to assess the effects of laws requiring ignition interlocks for some or all drunk driving offenders on alcohol-involved fatal crashes. A multilevel modeling approach assessed the effects of state interlock laws on alcohol-involved fatal crashes in the U.S. from 1982 to 2013. Monthly data on alcohol-involved crashes in each of the 50 states was collected in 2014 from the National Highway Traffic Safety Administration Fatality Analysis Reporting System. Random-intercept models accounted for between-state variation in alcohol-involved fatal crash rates and autocorrelation of within-state crash rates over time. Analysis was conducted in 2015. State laws requiring interlocks for all drunk driving offenders were associated with a 7% decrease in the rate of BAC >0.08 fatal crashes and an 8% decrease in the rate of BAC ≥0.15 fatal crashes, translating into an estimated 1,250 prevented BAC >0.08 fatal crashes. Laws requiring interlocks for segments of high-risk drunk driving offenders, such as repeat offenders, may reduce alcohol-involved fatal crashes after 2 years of implementation. Ignition interlock laws reduce alcohol-involved fatal crashes. Increasing the spread of interlock laws that are mandatory for all offenders would have significant public health benefit. Copyright © 2016 American Journal of Preventive Medicine. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Woodruff, Steven D; Mcintyre, Dustin L
2015-01-13
A method and device for providing a laser interlock having a first optical source, a first beam splitter, a second optical source, a detector, an interlock control system, and a means for producing dangerous optical energy. The first beam splitter is optically connected to the first optical source, the first detector and the second optical source. The detector is connected to the interlock control system. The interlock control system is connected to the means for producing dangerous optical energy and configured to terminate its optical energy production upon the detection of optical energy at the detector from the second opticalmore » source below a predetermined detector threshold. The second optical source produces an optical energy in response to optical energy from the first optical source. The optical energy from the second optical source has a different wavelength, polarization, modulation or combination thereof from the optical energy of the first optical source.« less
Performances of metal concentrations from three permeable pavement infiltrates.
Liu, Jiayu; Borst, Michael
2018-06-01
The U.S. Environmental Protection Agency constructed a 4000-m 2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each permeable pavement infiltrate, surface runoff from traditional asphalt, and rainwater were analyzed in duplicate for 22 metals (total and dissolved) for 6 years. In more than 99% of the samples, the concentration of barium, chromium, copper, manganese, nickel and zinc, and in 60%-90% of the samples, the concentration of arsenic, cadmium, lead, and antimony in infiltrates from all three permeable pavements met both the groundwater effluent limitations (GEL) and maximum contaminant levels (MCL). The concentration of aluminum (50%) and iron (93%) in PICP infiltrates samples exceed the GELs; however, the concentration in more than 90% samples PA and PC infiltrates met the GELs. No measurable difference in metal concentrations was found from the five sources for arsenic, cadmium, lead, antimony, and tin. Large concentrations of eleven metals, including manganese, copper, aluminum, iron, calcium, magnesium, sodium, potassium, silica, strontium and vanadium, were detected in surface runoff than the rainwater. Chromium, copper, manganese, nickel, aluminum, zinc, iron and magnesium concentrations in PICP infiltrates; calcium, barium, and strontium concentrations in PA infiltrates; sodium, potassium and vanadium concentrations in PC infiltrates were statistically larger than the other two permeable pavement infiltrates. Published by Elsevier Ltd.
Quantifying Evaporation in a Permeable Pavement System ...
Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. The U.S. Environmental Protection Agency (USEPA) constructed a 0.4-ha parking lot in Edison, NJ, that incorporated three different permeable pavement types in the parking lanes – permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). An impermeable liner installed 0.4 m below the driving surface in four 11.6-m by 4.74-m sections per each pavement type captures all infiltrating water and routes it to collection tanks that can contain events up to 38 mm. Each section has a design impervious area to permeable pavement area ratio of 0.66:1. Pressure transducers installed in the underdrain collection tanks measured water level for 24 months. Level was converted to volume using depth-to-volume ratios for individual collection tanks. Using a water balance approach, the measured infiltrate volume was compared to rainfall volume on an event-basis to determine the rainfall retained in the pavement strata and underlying aggregate. Evaporation since the previous event created additional storage in the pavement and aggregate layers. Events were divided into three groups based on antecedent dry period (ADP) and three, four-month categories of potential e
Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions
NASA Astrophysics Data System (ADS)
Lefebvre, M.; Boussu, F.; Coutellier, D.; Vallee, D.
2012-08-01
The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices) may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP) impact. During this research, several parameters has being studied as the influence of the yarns insertions [1-4], the degradation of the yarns during the weaving process [5-7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two processes. The first is a classical vacuum resin infusion; the second used a press in order to reach a resin ratio near to the existing protection. The existing protection is a prepreg structure with a fibre content of 88%. It has been revealed that a resin rate less than 35% inside the warp interlocks composite material leads to have equivalent ballistics performances than existing protection.
49 CFR 1242.17 - Signals and interlockers (accounts XX-17-19 and XX-18-19).
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 9 2010-10-01 2010-10-01 false Signals and interlockers (accounts XX-17-19 and XX... RAILROADS 1 Operating Expenses-Way and Structures § 1242.17 Signals and interlockers (accounts XX-17-19 and XX-18-19). Separate common expenses on the basis of the total train-hours in running service, and/or...
A Handbook for Automatic Data Processing Equipment Acquisition.
1981-12-01
Navy ADPE Procurement Policies (Automatic Data Processing Equipment (ADPE) procurement by federal agencies is governed by an interlocking network of...ADPE) procurement by federal agencies is governed by an interlocking network of policies and directives issued by federal agencies, the Department...SECNAVINST) and local procedures governing the acquisition of ADPE. Obtaining and understanding this interlocking network of policies is often difficult
Interlocking wettable ceramic tiles
Tabereaux, Jr., Alton T.; Fredrickson, Guy L.; Groat, Eric; Mroz, Thomas; Ulicny, Alan; Walker, Mark F.
2005-03-08
An electrolytic cell for the reduction of aluminum having a layer of interlocking cathode tiles positioned on a cathode block. Each tile includes a main body and a vertical restraining member to prevent movement of the tiles away from the cathode block during operation of the cell. The anode of the electrolytic cell may be positioned about 1 inch from the interlocking cathode tiles.
Vokey, F J; Guard, C L; Erb, H N; Galton, D M
2001-12-01
A 15-wk 2 x 3 factorial trial in a university dairy herd compared the effects of two alley surfaces and three free-stall beds on indices of lameness. Alley surfaces were grooved concrete (Ct) or 1.9-cm-thick interlocking rubber mats (R). Stalls were deep sand (S), rubber mattresses (M), or concrete (C). Mattress and concrete stalls were bedded with sawdust. At wk 1 and 15, the hind claws and hocks of 120 primi- (n = 69) and multiparous (n = 51) cows were scored for lesions and three claw measurements (dorsal wall length, heel depth, and toe angle) were recorded. Rates of lateral and medial claw growth and wear were calculated by measuring the migration of a reference mark away from the coronet. Digital photographs of claw surfaces were used to rescore claw lesions. Clinical lameness was evaluated by assigning a locomotion score from 1 to 4 to each cow during wk 1, 5, 10, and 14. Digital dermatitis (present/not present) and interdigital dermatitis (mild, moderate, or severe) were recorded at wk 15. The number of days that cows spent in a hospital barn was recorded. Before assignment, cows were professionally foot trimmed, sorted by initial claw lesion score, and then randomized in consecutive blocks of three to stall treatments. Photograph scores were highly repeatable. Nonparametric statistical techniques were used for analyses of rank data. Claw lesion score increased significantly for all treatment groups except RC and RS; however, when early lactation cows were excluded, no differences were found between treatment groups. Hock scores increased significantly more for cows in CtC than in CtS or RS. Significantly more animals from RC spent more than 10 d in the hospital pen compared with RM and RS. Groups did not significantly differ for clinical lameness. Cows in RS and RC had significantly lower rates for lateral claw net growth than those in CtM. Having moderate or severe interdigital dermatitis at wk 15 was associated with greater increases in claw lesion score and more treatments for digital dermatitis. All claw measurements were correlated; however, toe angle was most strongly correlated with the other two. In this experiment, stall and alley configurations did not lead to significant differences in several indices of lameness.
Reinhardt, Sophia; Martin, Heiner; Ulmar, Benjamin; Döbele, Stefan; Zwipp, Hans; Rammelt, Stefan; Richter, Martinus; Pompach, Martin; Mittlmeier, Thomas
2016-08-01
Open reduction and internal fixation with a plate is deemed to represent the gold standard of surgical treatment for displaced intra-articular calcaneal fractures. Standard plate fixation is usually placed through an extended lateral approach with high risk for wound complications. Minimally invasive techniques might avoid wound complications but provide limited construct stability. Therefore, 2 different types of locking nails were developed to allow for minimally invasive technique with sufficient stability. The aim of this study was to quantify primary stability of minimally invasive calcaneal interlocking nail systems in comparison to a variable-angle interlocking plate. After quantitative CT analysis, a standardized Sanders type IIB fracture model was created in 21 fresh-frozen cadavers. For osteosynthesis, 2 different interlocking nail systems (C-Nail; Medin, Nov. Město n. Moravě, Czech Republic; Calcanail; FH Orthopedics SAS; Heimsbrunn, France) as well as a polyaxial interlocking plate (Rimbus; Intercus GmbH; Rudolstadt, Germany) were used. Biomechanical testing consisted of a dynamic load sequence (preload 20 N, 1000 N up to 2500 N, stepwise increase of 100 N every 100 cycles, 0.5 mm/s) and a load to failure sequence (max. load 5000 N, 0.5 mm/s). Interfragmentary movement was detected via a 3-D optical measurement system. Boehler angle was measured after osteosynthesis and after failure occurred. No significant difference regarding load to failure, stiffness, Boehler angle, or interfragmentary motion was found between the different fixation systems. A significant difference was found with the dynamic failure testing sequence where 87.5% of the Calcanail implants failed in contrast to 14% of the C-Nail group (P < .01) and 66% of the Rimbus plate. The highest load to failure was observed for the C-Nail. Boehler angle showed physiologic range with all implants before and after the biomechanical tests. Both minimally invasive interlocking nail systems displayed a high primary stability that was not inferior to an interlocking plate. Based on our results, both interlocking nails appear to represent a viable option for treating displaced intra-articular calcaneal fractures. © The Author(s) 2016.
Ferrocene-containing non-interlocked molecular machines.
Scottwell, Synøve Ø; Crowley, James D
2016-02-11
Ferrocene is the prototypical organometallic sandwich complex and despite over 60 years passing since the discovery and elucidation of ferrocene's structure, research into ferrocene-containing compounds continues to grow as potential new applications in catalysis, biology and the material sciences are found. Ferrocene is chemically robust and readily functionalized which enables its facile incorporation into more complex molecular systems. This coupled with ferrocene's reversible redox properties and ability function as a "molecular ball bearing" has led to the use of ferrocene as a component in wide range of interlocked and non-interlocked synthetic molecular machine systems. This review will focus on the exploitation of ferrocene (and related sandwich complexes) for the development of non-interlocked synthetic molecular machines.
Jiao, Junrong; Zhang, Feilong; Jiao, Tian; Gu, Zhen
2018-01-01
Abstract Velcro, the most typical hook‐loop interlocker, often suffers from undesirable deformation, breaking, and noise because of the structure of the hook. Inspired by the arrester system of dragonfly, a new mechanical interlocker with a nylon pestle instead of the traditional hook is developed. The pestle‐loop mechanical interlocker shows a tunable peeling force from 0.4 ± 0.14 to 6.5 ± 0.72 N and the shear adhesion force of pestle‐loop mechanical interlocker is about twice as much as that of velcro. The pestle tape can be separated and fastened with the loop tape up to 30 000 cycles while keeping the original adhesive force and the pestle structure. In comparison, only after 4000 cycles most hooks of the commercial velcro are deformed and even broken, completely losing their adhesive function and their hook structure. These experimental results are further supported by finite element simulitions—the base of pestle mainly bears the separation‐caused strain while the middle of hook does. Notably, the sound volume during the separation of pestle‐loop mechanical interlocker is merely 49 ± 7.4 dB, much lower than 70 ± 3.5 dB produced by the velcro. PMID:29721425
Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture.
Khan, Irfanullah; Javed, Shahzad; Khan, Gauhar Nawaz; Aziz, Amer
2013-03-01
To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Case series. Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function.
DOT National Transportation Integrated Search
2005-02-01
This report presents the research undertaken within two areas of study of thin asphalt concrete (AC) overlays to rehabilitate : continuously reinforced concrete pavements (CRCP). The first one is the development of a decision tree for the project : s...
Evaluation of thin epoxy system overlays for concrete bridge decks : final report.
DOT National Transportation Integrated Search
1991-12-01
Four overlay systems were applied to concrete bridge decks in north Louisiana in May 1995 to evaluate their performance as friction surface and also as concrete sealers. Dural Flexolith, Poly-Carb Flexogrid, and Con/Chem Con/Crete were placed on thre...
Monitoring the corrosion process of reinforced concrete using BOTDA and FBG sensors.
Mao, Jianghong; Chen, Jiayun; Cui, Lei; Jin, Weiliang; Xu, Chen; He, Yong
2015-04-15
Expansion and cracking induced by the corrosion of reinforcement concrete is the major factor in the failure of concrete durability. Therefore, monitoring of concrete cracking is critical for evaluating the safety of concrete structures. In this paper, we introduce a novel monitoring method combining Brillouin optical time domain analysis (BOTDA) and fiber Bragg grating (FBG), based on mechanical principles of concrete expansion cracking. BOTDA monitors concrete expansion and crack width, while FBG identifies the time and position of cracking. A water-pressure loading simulation test was carried out to determine the relationship between fiber strain, concrete expansion and crack width. An electrical accelerated corrosion test was also conducted to evaluate the ability of this novel sensor to monitor concrete cracking under practical conditions.
Evaluation of Glass Fiber Reinforced Concrete Panels for Use in Military Construction.
1984-06-01
AD-A158 134 UNCLASSIFIED EVALUATION OF GLASS FIBER REINFORCED CONCRETE PANELS FOR USE IN MILITARY. . (U) CONSTRUCTION ENGINEERING RESEARCH LAB...Construction Engineering Research Laboratory i=h-C=iU. TECHNICAL REPORT M-85/15 June 1985 AD-A158 134 0~- 8 Evaluation of Glass Fiber ...Reinforced Concrete Panels for Use in Military Construction by Gilbert R. Williamson Glass fiber reinforced concrete (GFRC) materials are investigated
Dynamic Impact Analyses and Tests of Concrete Overpacks - 13638
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Sanghoon; Cho, Sang-Soon; Kim, Ki-Young
Concrete cask is an option for spent nuclear fuel interim storage which is prevailingly used in US. A concrete cask usually consists of metallic canister which confines the spent nuclear fuel and concrete overpack. When the overpack undergoes a severe missile impact which might be caused by a tornado or an aircraft crash, it should sustain acceptable level of structural integrity so that its radiation shielding capability and the retrievability of canister are maintained. Missile impact against a concrete overpack involves two damage modes, local damage and global damage. Local damage of concrete is usually evaluated by empirical formulas whilemore » the global damage is evaluated by finite element analysis. In many cases, those two damage modes are evaluated separately. In this research, a series of numerical simulations are performed using finite element analysis to evaluate the global damage of concrete overpack as well as its local damage under high speed missile impact. We consider two types of concrete overpack, one with steel in-cased concrete without reinforcement and the other with partially-confined reinforced concrete. The numerical simulation results are compared with test results and it is shown that appropriate modeling of material failure is crucial in this analysis and the results are highly dependent on the choice of failure parameters. (authors)« less
An evaluation of the Swedish ignition interlock program.
Bjerre, Bo
2003-01-01
The Swedish alcohol ignition interlock program for driving while intoxicated (DWI) offenders, both first-time as well as multiple offenders, was launched as a pilot project in 1999. It is a volunteer program and differs in some respects from other programs: It covers a period of 2 years, it includes very strict medical regulations entailing regular checkups by a physician, it does not require a prior period of hard suspension, and it focuses strongly on changes in alcohol habits. Records from the 5 years prior to the offence showed that DWI offenders are generally in a high-risk category long before their offense, with a four to five times higher accident rate (road accidents reported by the police) and a three to four times higher rate of hospitalization due to a road accident. Only 12% of the eligible DWI offenders took part in the program and, of these, 60% could be diagnosed as alcohol dependent or alcohol abusers. During the program, alcohol consumption is monitored through self-esteem questionnaires (AUDIT) and five different biological markers. Our data show a noticeable reduction in alcohol consumption among the interlock users. This, combined with the high rate of compliance with the regulations, probably accounts for the fact that there was no case of recidivism during the program. Preliminary findings also suggest a reduction in the annual accident rate for interlock users while in the program. It still is too early to draw any conclusions concerning the rate of recidivism after completion of the program due to an insufficient amount of data for analysis. Nevertheless, the preliminary results are so promising that the program will now be expanded to cover all of Sweden as well as to include all driver's license categories.
Daolagupu, Arup K; Mudgal, Ashwani; Agarwala, Vikash; Dutta, Kaushik K
2017-01-01
Extraarticular distal tibial fractures are among the most challenging fractures encountered by an orthopedician for treatment because of its subcutaneous location, poor blood supply and decreased muscular cover anteriorly, complications such as delayed union, nonunion, wound infection, and wound dehiscence are often seen as a great challenge to the surgeon. Minimally invasive plate osteosynthesis (MIPO) and intramedullary interlocking nail (IMLN) are two well-accepted and effective methods, but each has been historically related to complications. This study compares clinical and radiological outcome in extraarticular distal tibia fractures treated by intramedullary interlocking nail (IMLN) and minimally invasive plate osteosynthesis (MIPO). 42 patients included in this study, 21 underwent IMLN and 21 were treated with MIPO who met the inclusion criteria and operated between June 2014 and May 2015. Patients were followed up for clinical and radiological evaluation. In IMLN group, average union time was 18.26 weeks compared to 21.70 weeks in plating group which was significant ( P < 0.0001). Average time required for partial and full weight bearing in the nailing group was 4.95 weeks and 10.09 weeks respectively which was significantly less ( P < 0.0001) as compared to 6.90 weeks and 13.38 weeks in the plating group. Lesser complications in terms of implant irritation, ankle stiffness, and infection, were seen in interlocking group as compared to plating group. Average functional outcome according to American Orthopedic Foot and Ankle Society score was measured which came out to be 96.67. IMLN group was associated with lesser duration of surgery, earlier weight bearing and union rate, lesser incidence of infection and implant irritation which makes it a preferable choice for fixation of extra-articular distal tibial fractures. However, larger randomized controlled trials are required for confirming the results.
Cyndari, Karen I; Goodheart, Jacklyn R; Miller, Mark A; Oest, Megan E; Damron, Timothy A; Mann, Kenneth A
2017-07-01
Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock. Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock. The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm 2 (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE. PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors. Copyright © 2017 Elsevier Inc. All rights reserved.
Bawden, Gerald W.; Bond, Sandra; Podoski, J. H.; Kreylos, O.; Kellogg, L. H.
2012-01-01
We used ground-based Tripod LiDAR (T-LiDAR) to assess the stability of two engineered structures: a bridge spanning the San Andreas fault following the M6.0 Parkfield earthquake in Central California and a newly built coastal breakwater located at the Kaumālapa`u Harbor Lana'i, Hawaii. In the 10 weeks following the earthquake, we found that the surface under the bridge shifted 7.1 cm with an additional 2.6 cm of motion in the subsequent 13 weeks, which deflected the bridge's northern I-beam support 4.3 cm and 2.1 respectively; the bridge integrity remained intact. T-LiDAR imagery was collected after the completion of armored breakwater with 817 35-ton interlocking concrete armor units, Core-Locs®, in the summers of 2007, 2008 and 2010. We found a wide range of motion of individual Core-Locs, from a few centimeters to >110 cm along the ocean side of the breakwater, with lesser movement along the harbor side.
Interlocking egg-crate type grid assembly
Kast, Steven J.
1987-01-01
Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120.degree. at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking and interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.
Interlocking egg-crate type grid assembly
Kast, S.J.
1985-03-15
Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120/sup 0/ at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.
Wang, Xiao-Yong
2017-01-26
Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. First, the hydration model analyzes the dilution effect and the nucleation effect of limestone during the hydration of cement. The degree of cement hydration is calculated by considering concrete mixing proportions, binder properties, and curing conditions. Second, by using the gel-space ratio, the compressive strength of PLC concrete is evaluated. The interactions among water-to-binder ratio, limestone replacement ratio, and strength development are highlighted. Third, the carbonate material contents and porosity are calculated from the hydration model and are used as input parameters for the carbonation model. By considering concrete microstructures and environmental conditions, the carbon dioxide diffusivity and carbonation depth of PLC concrete are evaluated. The proposed model has been determined to be valid for concrete with various water-to-binder ratios, limestone contents, and curing periods.
Wang, Xiao-Yong
2017-01-01
Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. First, the hydration model analyzes the dilution effect and the nucleation effect of limestone during the hydration of cement. The degree of cement hydration is calculated by considering concrete mixing proportions, binder properties, and curing conditions. Second, by using the gel–space ratio, the compressive strength of PLC concrete is evaluated. The interactions among water-to-binder ratio, limestone replacement ratio, and strength development are highlighted. Third, the carbonate material contents and porosity are calculated from the hydration model and are used as input parameters for the carbonation model. By considering concrete microstructures and environmental conditions, the carbon dioxide diffusivity and carbonation depth of PLC concrete are evaluated. The proposed model has been determined to be valid for concrete with various water-to-binder ratios, limestone contents, and curing periods. PMID:28772472
Evaluation of consolidation in concrete pavements.
DOT National Transportation Integrated Search
1994-01-01
Petrographic examinations of specimens from two recently constructed concrete pavements suggested that complete consolidation of the concrete may not have been achieved. Consequently, a quantitative evaluation of the degree of consolidation in these ...
Yang, Linlin; Jing, Xu; An, Bowen; He, Cheng; Yang, Yang; Duan, Chunying
2018-01-28
By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system.
Experimental Investigation About Stamping Behaviour of 3D Warp Interlock Composite Preforms
NASA Astrophysics Data System (ADS)
Dufour, Clément; Wang, Peng; Boussu, François; Soulat, Damien
2014-10-01
Forming of continuous fibre reinforcements and thermoplastic resin commingled prepregs can be performed at room temperature due to its similar textile structure. The "cool" forming stage is better controlled and more economical. The increase of temperature and the resin consolidation phases after the forming can be carried out under the isothermal condition thanks to a closed system. It can avoid the manufacturing defects easily experienced in the non-isothermal thermoforming, in particular the wrinkling [1]. Glass/Polypropylene commingled yarns have been woven inside different three-dimensional (3D) warp interlock fabrics and then formed using a double-curved shape stamping tool. The present study investigates the in-plane and through-thickness behaviour of the 3D warp interlock fibrous reinforcements during forming with a hemispherical punch. Experimental data allow analysing the forming behaviour in the warp and weft directions and on the influence of warp interlock architectures. The results point out that the layer to layer warp interlock preform has a better stamping behaviour, in particular no forming defects and good homogeneity in thickness.
Development of Interlocking Masonry Bricks and its’ Structural Behaviour: A Review Paper
NASA Astrophysics Data System (ADS)
Al-Fakih, Amin; Mohammed, Bashar S.; Nuruddin, Fadhil; Nikbakht, Ehsan
2018-04-01
Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today’s construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.
Estimating Durability of Reinforced Concrete
NASA Astrophysics Data System (ADS)
Varlamov, A. A.; Shapovalov, E. L.; Gavrilov, V. B.
2017-11-01
In this article we propose to use the methods of fracture mechanics to evaluate concrete durability. To evaluate concrete crack resistance characteristics of concrete directly in the structure in order to implement the methods of fracture mechanics, we have developed special methods. Various experimental studies have been carried out to determine the crack resistance characteristics and the concrete modulus of elasticity during its operating. A comparison was carried out for the results obtained with the use of the proposed methods and those obtained with the standard methods for determining the concrete crack resistance characteristics.
Monitoring the Corrosion Process of Reinforced Concrete Using BOTDA and FBG Sensors
Mao, Jianghong; Chen, Jiayun; Cui, Lei; Jin, Weiliang; Xu, Chen; He, Yong
2015-01-01
Expansion and cracking induced by the corrosion of reinforcement concrete is the major factor in the failure of concrete durability. Therefore, monitoring of concrete cracking is critical for evaluating the safety of concrete structures. In this paper, we introduce a novel monitoring method combining Brillouin optical time domain analysis (BOTDA) and fiber Bragg grating (FBG), based on mechanical principles of concrete expansion cracking. BOTDA monitors concrete expansion and crack width, while FBG identifies the time and position of cracking. A water-pressure loading simulation test was carried out to determine the relationship between fiber strain, concrete expansion and crack width. An electrical accelerated corrosion test was also conducted to evaluate the ability of this novel sensor to monitor concrete cracking under practical conditions. PMID:25884790
NASA Astrophysics Data System (ADS)
Zamer, M. M.; Irwan, J. M.; Othman, N.; Faisal, S. K.; Anneza, L. H.; Alshalif, A. F.; Teddy, T.
2017-11-01
Interlocking compressed earth blocks (ICEB) are soil based blocks that allows for mortarless construction. The addition of many alternative materials into interlocking block in order to improve the durability has been reported. However there are currently lack of report and evidence on the application of biocalcification or microbiologically induced calcite precipitation (MICP) in improving the engineering properties of ICEB. This paper evaluate the effect of UB in improving the water absorption properties of ICEB. This paper also provide the results on SEM analysis of addition of 1%, 3% and 5% UB in ICEB. The bacteria were added as partial replacement of limestone water in ICEB. The results showed the reduction of 14.72% with 5% UB on initial water absorption followed by the results for water absorption by 24-hour soaking which also indicates reduction of 14.68% with 5% UB on 28th days of testing compared to control specimen. It was expected that the reduction of water absorption was due to the plugging of pores by the bacterial calcite which prevent ingression of water in ICEB samples. Therefore this study hopes that the positive results from the UB as improving in water absorption of ICEB will lead to improve others ICEB properties and others construction materials.
Evaluation of concrete patching materials : final report.
DOT National Transportation Integrated Search
1985-01-01
The project evaluated numerous repairs on portland cement concrete pavements and bridge decks made with a number of laboratory accepted, proprietary patching materials and portland cement concrete mixtures of different designs. It was ascertained tha...
Zhao, Hewei; Yue, Yonghai; Guo, Lin; Wu, Juntao; Zhang, Youwei; Li, Xiaodong; Mao, Shengcheng; Han, Xiaodong
2016-07-01
Ceramic/polymer composite equipped with 3D interlocking skeleton (3D IL) is developed through a simple freeze-casting method, exhibiting exceptionally light weight, high strength, toughness, and shock resistance. Long-range crack energy dissipation enabled by 3D interlocking structure is considered as the primary reinforcing mechanism for such superior properties. The smart composite design strategy should hold a place in developing future structural engineering materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Probabilistic design of fibre concrete structures
NASA Astrophysics Data System (ADS)
Pukl, R.; Novák, D.; Sajdlová, T.; Lehký, D.; Červenka, J.; Červenka, V.
2017-09-01
Advanced computer simulation is recently well-established methodology for evaluation of resistance of concrete engineering structures. The nonlinear finite element analysis enables to realistically predict structural damage, peak load, failure, post-peak response, development of cracks in concrete, yielding of reinforcement, concrete crushing or shear failure. The nonlinear material models can cover various types of concrete and reinforced concrete: ordinary concrete, plain or reinforced, without or with prestressing, fibre concrete, (ultra) high performance concrete, lightweight concrete, etc. Advanced material models taking into account fibre concrete properties such as shape of tensile softening branch, high toughness and ductility are described in the paper. Since the variability of the fibre concrete material properties is rather high, the probabilistic analysis seems to be the most appropriate format for structural design and evaluation of structural performance, reliability and safety. The presented combination of the nonlinear analysis with advanced probabilistic methods allows evaluation of structural safety characterized by failure probability or by reliability index respectively. Authors offer a methodology and computer tools for realistic safety assessment of concrete structures; the utilized approach is based on randomization of the nonlinear finite element analysis of the structural model. Uncertainty of the material properties or their randomness obtained from material tests are accounted in the random distribution. Furthermore, degradation of the reinforced concrete materials such as carbonation of concrete, corrosion of reinforcement, etc. can be accounted in order to analyze life-cycle structural performance and to enable prediction of the structural reliability and safety in time development. The results can serve as a rational basis for design of fibre concrete engineering structures based on advanced nonlinear computer analysis. The presented methodology is illustrated on results from two probabilistic studies with different types of concrete structures related to practical applications and made from various materials (with the parameters obtained from real material tests).
Bond characteristics of reinforcing steel embedded in geopolymer concrete
NASA Astrophysics Data System (ADS)
Kathirvel, Parthiban; Thangavelu, Manju; Gopalan, Rashmi; Raja Mohan Kaliyaperumal, Saravana
2017-07-01
The force transferring between reinforcing steel and the surrounding concrete in reinforced concrete is influenced by several factors. Whereas, the study on bond behaviour of geopolymer concrete (GPC) is lagging. In this paper, an experimental attempt has been made to evaluate the geopolymer concrete bond with reinforcing steel of different diameter and embedded length using standard pull out test. The geopolymer concrete is made of ground granulated blast furnace slag (GGBFS) as geopolymer source material (GSM). The tests were conducted to evaluate the development of bond between steel and concrete of grade M40 and M50 with 12 and 16 mm diameter reinforcing steel for geopolymer and cement concrete mixes and to develop a relation between bond strength and compressive strength. From the experimental results, it has been observed that the bond strength of the geopolymer concrete mixes was more compared to the cement concrete mixes and increases with the reduction in the diameter of the bar.
Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors.
Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo
2017-08-07
Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals.
Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors
Yoon, Hyejin; Kim, Young Jin; Kim, Hee Seok; Kang, Jun Won; Koh, Hyun-Moo
2017-01-01
Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal time and reducing construction time and costs. In this paper, the feasibility of using surface wave velocities to predict the strength of in situ concrete inside the form at a very early stage was evaluated. Ultrasonic sensors were used to measure a series of surface waves for concrete inside a form in the first 24 h after placement. A continuous wavelet transform was used to compute the travel time of the propagating surface waves. The cylindrical compressive strength and penetration resistance tests were also performed during the test period. Four mixtures and five curing temperatures were used for the specimens. The surface wave velocity was confirmed to be applicable to estimating the concrete strength at a very early age in wall-like elements. An empirical formula is proposed for evaluating the early-age compressive strength of concrete considering the 95% prediction intervals. PMID:28783128
Evaluating performance-based test and specifications for sulfate resistance in concrete
DOT National Transportation Integrated Search
2000-12-01
This research project involved an experimental evaluation of the sulfate resistance of various concretes and mortars for the purpose of establishing performance-based specifications for the durability of concrete against sulfate attack. The research ...
Nondestructive Measurements Using Mechanical Waves in Reinforced Concrete Structures.
DOT National Transportation Integrated Search
2014-02-01
"This study evaluated various techniques that use mechanical waves for the evaluation of critical concrete properties, : such as proper consolidation of the concrete during placement and strength development; changes in modulus; and the detection : o...
Evaluation of shrinkage and cracking in concrete of ring test by acoustic emission method
NASA Astrophysics Data System (ADS)
Watanabe, Takeshi; Hashimoto, Chikanori
2015-03-01
Drying shrinkage of concrete is one of the typical problems related to reduce durability and defilation of concrete structures. Lime stone, expansive additive and low-heat Portland cement are used to reduce drying shrinkage in Japan. Drying shrinkage is commonly evaluated by methods of measurement for length change of mortar and concrete. In these methods, there is detected strain due to drying shrinkage of free body, although visible cracking does not occur. In this study, the ring test was employed to detect strain and age cracking of concrete. The acoustic emission (AE) method was adopted to detect micro cracking due to shrinkage. It was recognized that in concrete using lime stone, expansive additive and low-heat Portland cement are effective to decrease drying shrinkage and visible cracking. Micro cracking due to shrinkage of this concrete was detected and evaluated by the AE method.
Poly[n]catenanes: Synthesis of molecular interlocked chains
NASA Astrophysics Data System (ADS)
Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong; Wojtecki, Rudy J.; de Pablo, Juan J.; Hore, Michael J. A.; Rowan, Stuart J.
2017-12-01
As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (~75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass ~21.4 kilograms per mole) to a mixture of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.
Fire resistant PV shingle assembly
Lenox, Carl J.
2012-10-02
A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.
Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru
2004-10-12
An advanced containment system for containing buried waste and associated leachate. A trench is dug on either side of the zone of interest containing the buried waste so as to accommodate a micro tunnel boring machine. A series of small diameter tunnels are serially excavated underneath the buried waste. The tunnels are excavated by the micro tunnel boring machine at a consistent depth and are substantially parallel to each other. As tunneling progresses, steel casing sections are connected end to end in the excavated portion of the tunnel so that a steel tube is formed. Each casing section has complementary interlocking structure running its length that interlocks with complementary interlocking structure on the adjacent casing section. Thus, once the first tube is emplaced, placement of subsequent tubes is facilitated by the complementary interlocking structure on the adjacent, previously placed, casing sections.
Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru
2005-05-24
An advanced containment system for containing buried waste and associated leachate. A trench is dug on either side of the zone of interest containing the buried waste so as to accommodate a micro tunnel boring machine. A series of small diameter tunnels are serially excavated underneath the buried waste. The tunnels are excavated by the micro tunnel boring machine at a consistent depth and are substantially parallel to each other. As tunneling progresses, steel casing sections are connected end to end in the excavated portion of the tunnel so that a steel tube is formed. Each casing section has complementary interlocking structure running its length that interlocks with complementary interlocking structure on the adjacent casing section. Thus, once the first tube is emplaced, placement of subsequent tubes is facilitated by the complementary interlocking structure on the adjacent, previously placed, casing sections.
Evaluation of various coarse aggregate concretes : final report.
DOT National Transportation Integrated Search
1983-10-01
This study was initiated to determine the properties of concrete using three types of coarse aggregate. The coarse aggregates evaluated in this study included silicious gravel, the standard aggregate for concrete in the state, with sandstone and lime...
Report of concrete pavement evaluation : project 105 C-4181-01 Donahoo Road, Wyandotte County.
DOT National Transportation Integrated Search
2013-12-01
The physical properties of hardened concrete cores and fresh concrete test results were compared with aggregate : gradation workability differences. The concrete cores were taken from a rural two-lane concrete road in northeastern Kansas : constructe...
Djumas, Lee; Molotnikov, Andrey; Simon, George P; Estrin, Yuri
2016-05-24
Structural composites inspired by nacre have emerged as prime exemplars for guiding materials design of fracture-resistant, rigid hybrid materials. The intricate microstructure of nacre, which combines a hard majority phase with a small fraction of a soft phase, achieves superior mechanical properties compared to its constituents and has generated much interest. However, replicating the hierarchical microstructure of nacre is very challenging, not to mention improving it. In this article, we propose to alter the geometry of the hard building blocks by introducing the concept of topological interlocking. This design principle has previously been shown to provide an inherently brittle material with a remarkable flexural compliance. We now demonstrate that by combining the basic architecture of nacre with topological interlocking of discrete hard building blocks, hybrid materials of a new type can be produced. By adding a soft phase at the interfaces between topologically interlocked blocks in a single-build additive manufacturing process, further improvement of mechanical properties is achieved. The design of these fabricated hybrid structures has been guided by computational work elucidating the effect of various geometries. To our knowledge, this is the first reported study that combines the advantages of nacre-inspired structures with the benefits of topological interlocking.
DOT National Transportation Integrated Search
2002-09-01
This report presents the results of an evaluation of concrete slab fracturing techniques as a means of arresting or retarding reflective cracking through asphalt overlays placed on severely distressed portland cement concrete pavement. The study invo...
Laboratory testing of alcohol safety interlock systems employing divided attention tests
DOT National Transportation Integrated Search
1975-12-01
Author's abstract: Prototype Alcohol Safety Interlock Systems employing measurements of tracking ability, reaction time, and response accuracy to discern alcohol impairment were submitted to laboratory testing. These systems were modified versions of...
Alcohol ignition interlock service support
DOT National Transportation Integrated Search
1992-12-01
Author's abstract: This Technical Report was produced under Contract No. DTNH22-89-C-07009 for the National Highway Traffic Safety Administration. Under that same contract, a draft set of model specifications for Breath Alcohol Ignition Interlock Dev...
DOT National Transportation Integrated Search
2009-03-01
The research described here has resulted in the development of a simplistic and innovative interlocking : glulam bridge deck panel for use in temporary bridge deck applications. The key feature of this panel : system is the interlocking tongue and gr...
DOT National Transportation Integrated Search
2017-08-01
The objectives of this exploratory study were to determine (a) how ignition interlock data is used for DWI offender monitoring and offender-related programs, such as screening, assessments, and treatment for alcohol abuse problems; and (b) if the int...
Jumbo Cutter for Removal of A Bent Femoral Interlocking Nail: A Cost Effective Method
Dhanda, Manjeet Singh; Sharma, Sansar C; Ali, Nadeem; Bhat, Abedullah
2015-01-01
Closed diaphyseal femoral shaft fractures can be treated with multiple surgical options. It is more challenging to remove a bent nail than a broken one because it is difficult to retrieve the bent nail through the intramedullary canal. Various authors have published their techniques for removal of bent femoral interlocking nail. This article describes a simple technique using Jumbo cutter for sectioning and removal of bent interlocking nail. This technique will help orthopaedic surgeons to remove bent nail without using any specialised metal cutting instruments. PMID:26266173
Evaluation of Optional and/or Replacement Concrete Sealers
DOT National Transportation Integrated Search
2018-02-01
This is an In-House evaluation of products performed by ODOTs Office of Materials Management. ODOT Spends about $8M per year on coating concrete for esthetic purposes. Built into the coating is sealing capability to help protect the concrete and t...
DOT National Transportation Integrated Search
2013-12-01
The physical properties of hardened concrete cores and fresh concrete test results were compared with aggregate gradation workability differences. The concrete cores were taken from a rural two-lane concrete road in northeastern Kansas constructed in...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nesvijski, E.; Nesvijski, T.
1996-12-31
Concrete as one of the main construction materials, which is used for building of industrial and civil structures, highways, bridges, etc. requires periodical evaluation of its properties by different nondestructive methods. Application of acoustic emission (AE) for these purposes occupies a modest place among other nondestructive methods. But the AE methods proved to be very effective for testing of concrete and reinforced concrete elements and structures under load. This work is devoted to an important, from methodological point of view, problem connected with two opposite effects: of Kaiser and of Felicity, and their application for evaluation of concrete by themore » AE method.« less
23. Looking N up corridor from Chick Interlocking Tower. Boston, ...
23. Looking N up corridor from Chick Interlocking Tower. Boston, Suffolk Co., MA. Sec. 4116, MP 227.09. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA
Interlock Data Utilization : Traffic Tech
DOT National Transportation Integrated Search
2017-06-01
Driving-while-impaired (DWI) offenders present a high risk to traffic safety. Alcohol ignition interlocks are now widely used for DWI offenders and can significantly reduce DWI recidivism while on the offenders vehicle. In a typical year an interl...
NASA Astrophysics Data System (ADS)
Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong
2017-09-01
This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.
Mechanical interlocking of cotton fibers on slightly textured surfaces of metallic cylinders
Zhang, Youqiang; Tian, Yu; Meng, Yonggang
2016-01-01
Mechanical interlocking is widely applied in industry and general lives of human beings. In this work, we realized the control of locking or sliding states of cotton fibers on the metal surfaces with slightly different textures through traditional machining. Three types of sliding states, i.e., locking, one-way sliding, and two-way sliding have been achieved. It is found that the locking or sliding of the cotton fibers on the metallic cylinder depends on the friction coefficient and the ratio of cotton fiber diameter, 2r, to the height of the rough peaks, h, of metal surfaces. When the critical ratio h/r exceeds 1, the cotton fibers could tightly attach to the metallic surface through mechanical interlocking. This work provided a convenient and universal method for the control of interlocking or sliding of fiber-based materials on textured surfaces. PMID:27156720
Shults, Ruth A; Bergen, Gwen
2017-01-01
Ignition interlocks are effective in reducing recidivism among driving while intoxicated (DWI) offenders while installed on their vehicles. However, the devices are not widely used in the USA. This survey gauged public support for requiring ignition interlocks for all convicted DWI offenders including first-time offenders. 69% of respondents supported such a policy. Support was lowest (38%) among persons who reported drinking and driving in the past 30 days. Multivariate regression analysis indicated that support varied little by region, community size or most measured individual characteristics. Persons who did not drink and drive were 80% more likely to support the requirement than those who drink and drive. These findings suggest that laws requiring ignition interlocks for all convicted DWI offenders may face the most opposition in communities with high levels of drinking and driving. PMID:22773020
DOT National Transportation Integrated Search
2011-07-01
This report details results from testing that was conducted to determine the bond and time-dependent : characteristics of two lightweight concrete mixes. The lightweight mixes were evaluated to possibly : provide a more cost-effective solution to rep...
DOT National Transportation Integrated Search
1998-06-01
We used a simulated concrete pore water solution to evaluate the corrosion protection performance of concrete corrosion-inhibiting admixtures and epoxy-coated reinforcing bars (ECR). We evaluated three commercial corrosion inhibitors, ECR from three ...
Evaluation of thin epoxy system overlays for concrete bridge decks : interim report No. 1.
DOT National Transportation Integrated Search
1986-05-01
Four epoxy overlay systems were applied to concrete bridge decks in north Louisiana to evaluate their performance as skid resistant surfaces primarily and also as concrete sealers. Dural Flexolith, Poly-Carb Flexogrid, and Con/Chem Cono/Crete were pl...
Durability of saw-cut joints in plain cement concrete pavements : [technical summary].
DOT National Transportation Integrated Search
2011-01-01
The main objective of this study was to evaluate factors influencing the durability of the joints in portland cement concrete pavement in the state of Indiana. : The scope of the research included the evaluation of the absorption of water in concrete...
Corrosion protection performance evaluation of low permeable concretes in exposure specimens.
DOT National Transportation Integrated Search
1999-01-01
The application of a mineral admixture or a combination of a mineral admixture with corrosion inhibitor are the methods used for the corrosion protection for reinforced concrete bridges. The results of a 1.5-year study on evaluation of three concrete...
Evaluation of bridge deck with shrinkage-compensating concrete.
DOT National Transportation Integrated Search
2016-04-01
Concrete bridge decks are susceptible to premature cracking and to corrosion of reinforcing steel. Low-permeability : concrete does not always ensure durability if the concrete has excessive cracks that facilitate the intrusion of aggressive solution...
Ignition interlock : an investigation into rural Arizona judges’ perceptions.
DOT National Transportation Integrated Search
2014-05-01
This study sought to answer several questions regarding 2007 Arizona legislation requiring ignition interlock for all offenders convicted of Driving-Under-the-Influence (DUI), including first time DUI offenders. At the time the law was passed, Arizon...
Interlocked molecules: Moving into another dimension
NASA Astrophysics Data System (ADS)
Fournel-Marotte, Karine; Coutrot, Frédéric
2017-02-01
Molecular daisy-chain structures are typically made up of two interlocked components and can exhibit muscle-like contraction and extension in one dimension. Zinc-based multicomponent systems that can operate in two and three dimensions have now been designed and synthesized.
Ignition interlock: an investigation into rural Arizona judges' perceptions : traffic tech.
DOT National Transportation Integrated Search
2014-05-01
This study sought to answer several questions regarding 2007 : Arizona legislation requiring ignition interlock for all offenders : convicted of driving under the influence (DUI), including : first-time DUI offenders. At the time the law was passed, ...
Evaluation of concrete recycling system efficiency for ready-mix concrete plants.
Vieira, Luiz de Brito Prado; Figueiredo, Antonio Domingues de
2016-10-01
The volume of waste generated annually in concrete plants is quite large and has important environmental and economic consequences. The use of fresh concrete recyclers is an interesting way for the reuse of aggregates and water in new concrete production. This paper presents a study carried out for over one year by one of the largest ready-mix concrete producers in Brazil. This study focused on the evaluation of two recyclers with distinct material separation systems, herein referred to as drum-type and rotary sieve-type equipment. They were evaluated through characterization and monitoring test programs to verify the behaviour of recovered materials (aggregates, water, and slurry). The applicability of the recovered materials (water and aggregates) was also evaluated in the laboratory and at an industrial scale. The results obtained with the two types of recyclers used were equivalent and showed no significant differences. The only exception was in terms of workability. The drum-type recycler generated fewer cases that required increased pumping pressure. The analysis concluded that the use of untreated slurry is unfeasible because of its intense negative effects on the strength and workability of concrete. The reclaimed water, pre-treated to ensure that its density is less than 1.03g/cm(3), can be used on an industrial scale without causing any harm to the concrete. The use of recovered aggregates consequently induces an increase in water demand and cement consumption to ensure the workability conditions of concrete that is proportional to the concrete strength level. Therefore, the viability of their use is restricted to concretes with characteristic strengths lower than 25MPa. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOT National Transportation Integrated Search
2012-10-01
Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete concrete with at least ...
Evaluation of a nuclear gage for controlling the consolidation of fresh concrete : final report.
DOT National Transportation Integrated Search
1981-01-01
Evaluated was an approach to controlling the consolidation of in-place portland cement concrete on the basis of densities obtained with a Troxler 3411 nuclear gage. The gage was used in the backscatter mode on low-slump concrete bridge deck overlays ...
An evaluation of the performance of epoxy-coated reinforcing steel in concrete exposure specimens.
DOT National Transportation Integrated Search
1998-01-01
The application of a mineral admixture or a combination of a mineral admixture with corrosion inhibitor are the methods used for the corrosion protection for reinforced concrete bridges. The results of a 1.5-year study on evaluation of three concrete...
Metacarpophalangeal joint of the thumb arthrodesis using intramedullary interlocking screws XMCP™.
Novoa-Parra, C N; Montaner-Alonso, D; Morales-Rodríguez, J
2017-09-04
The study objective was to assess the results of a thumb metacarpophalangeal joint (MCPJ) arthrodesis using intramedullary interlocking screws at 25°, XMCP ™ (Extremity Medical, Parsippany, NJ). Radiographs evaluated the angle of arthrodesis, time of fusion and fixation of the implant. Clinical and functional outcomes were assessed using the DASH questionnaire and the VAS scale. Any complications found during surgery or the follow-up period were noted. We studied 9 patients. The mean follow-up was 27.6 months. Patients showed clinical and radiological evidence of fusion in an average of 8 weeks, the angle of fusion was 25°. There were no complications and no implant had to be removed. The XMCP™ system provides a reliable method for MCPJ arthrodesis for several indications and can be used with other procedures in the complex hand. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.
Evaluation of the shrinkage and creep of medium strength self compacting concrete
NASA Astrophysics Data System (ADS)
De La Cruz, C. J.; Ramos, G.; Hurtado, W. A.
2017-02-01
The difference between self compacting concrete (SCC) and conventional concrete (CC) is in fresh state, is the high fluidity at first and the need for vibration at second, but in hardened state, both concretes must comply with the resistance specified, in addition to securing the safety and functionality for which it was designed. This article describes the tests and results for shrinkage and creep at some medium strength Self Compacting Concrete with added sand (SCC-MSs) and two types of cement. The research was conducted at the Laboratorio de Tecnología de Estructuras (LTE) of the Universitat Politécnica de Catalunya (UPC), in dosages of 200 liters; with the idea of evaluating the effectiveness of implementation of these new concretes at elements designed with conventional concrete (CCs).
Use of improved materials systems in marine piling : final report.
DOT National Transportation Integrated Search
1982-12-01
This report contains the results of a study to evaluate the feasibility of manufacturing precast, prestressed marine pile from polymer concrete, polymer impregnated concrete, internally sealed concrete and latex modified concrete. Included in the rep...
Evaluation of models for predicting (total) creep of prestressed concrete mixtures.
DOT National Transportation Integrated Search
2001-01-01
Concrete experiences volume changes throughout its service life. When loaded, concrete experiences an instantaneous recoverable elastic deformation and a slow inelastic deformation called creep. Creep of concrete is composed of two components, basic ...
Crack classification in concrete beams using AE parameters
NASA Astrophysics Data System (ADS)
Bahari, N. A. A. S.; Shahidan, S.; Abdullah, S. R.; Ali, N.; Zuki, S. S. Mohd; Ibrahim, M. H. W.; Rahim, M. A.
2017-11-01
The acoustic emission (AE) technique is an effective tool for the evaluation of crack growth. The aim of this study is to evaluate crack classification in reinforced concrete beams using statistical analysis. AE has been applied for the early monitoring of reinforced concrete structures using AE parameters such as average frequency, rise time, amplitude counts and duration. This experimental study focuses on the utilisation of this method in evaluating reinforced concrete beams. Beam specimens measuring 150 mm × 250 mm × 1200 mm were tested using a three-point load flexural test using Universal Testing Machines (UTM) together with an AE monitoring system. The results indicated that RA value can be used to determine the relationship between tensile crack and shear movement in reinforced concrete beams.
Examining the feasibility of alcohol ignition interlocks for motorcycles : traffic tech.
DOT National Transportation Integrated Search
2017-05-01
Impaired driving is a major factor in vehicle crashes and traffic : fatalities. The use of alcohol ignition interlocks is growing as a : countermeasure to combat the high rate of offender recidivism : for Driving While Intoxicated (DWI); however, whi...
49 CFR 236.751 - Interlocking, manual.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Interlocking, manual. 236.751 Section 236.751 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... so interconnected by means of mechanical and/or electric locking that their movements must succeed...
49 CFR 236.750 - Interlocking, automatic.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... manually, and which are so interconnected by means of electric circuits that their movements must succeed...
Innovative monitoring of 3D warp interlock fabric during forming process
NASA Astrophysics Data System (ADS)
Dufour, C.; Jerkovic, I.; Wang, P.; Boussu, F.; Koncar, V.; Soulat, D.; Grancaric, A. M.; Pineau, P.
2017-10-01
The final geometry of 3D warp interlock fabric needs to be check during the 3D forming step to ensure the right locations of warp and weft yarns inside the final structure. Thus, a new monitoring approach has been proposed based on sensor yarns located in the fabric thickness. To ensure the accuracy of measurements, the observation of the surface deformation of the 3D warp interlock fabric has been joined to the sensor yarns measurements. At the end, it has been revealed a good correlation between strain measurement done globally by camera and locally performed by sensor yarns.
Djumas, Lee; Molotnikov, Andrey; Simon, George P.; Estrin, Yuri
2016-01-01
Structural composites inspired by nacre have emerged as prime exemplars for guiding materials design of fracture-resistant, rigid hybrid materials. The intricate microstructure of nacre, which combines a hard majority phase with a small fraction of a soft phase, achieves superior mechanical properties compared to its constituents and has generated much interest. However, replicating the hierarchical microstructure of nacre is very challenging, not to mention improving it. In this article, we propose to alter the geometry of the hard building blocks by introducing the concept of topological interlocking. This design principle has previously been shown to provide an inherently brittle material with a remarkable flexural compliance. We now demonstrate that by combining the basic architecture of nacre with topological interlocking of discrete hard building blocks, hybrid materials of a new type can be produced. By adding a soft phase at the interfaces between topologically interlocked blocks in a single-build additive manufacturing process, further improvement of mechanical properties is achieved. The design of these fabricated hybrid structures has been guided by computational work elucidating the effect of various geometries. To our knowledge, this is the first reported study that combines the advantages of nacre-inspired structures with the benefits of topological interlocking. PMID:27216277
On Critical States, Rupture States and Interlocking Strength of Granular Materials.
Szalwinski, Chris M
2017-07-27
The Mohr-Coulomb theory of strength identifies cohesion and internal friction as the two principal contributions to the shear strength of a granular material. The contribution of cohesion in over-compacted granular materials has been challenged and replacing cohesion with interlocking has been proposed. A theory of rupture strength that includes interlocking is derived herein. The physics-chemistry concept of critical state is elaborated to accommodate granular materials, based on empirical definitions established in the fields of soil mechanics and bulk solids' flow. A surface in state space, called the critical compaction surface, separates over-compacted states from lightly compacted states. The intersection of this surface with the Mohr-Coulomb envelope forms the critical state surface for a granular material. The rupture strength of an over-compacted granular material is expressed as the sum of cohesion, internal friction and interlocking strength. Interlocking strength is the shear strength contribution due to over-compaction and vanishes at critical state. The theory allows migrations from one critical state to another. Changes in specific volume during such migrations are related to changes in mean-normal effective stress and uncoupled from changes in shearing strain. The theory is reviewed with respect to two established research programs and underlying assumptions are identified.
DOT National Transportation Integrated Search
2014-06-01
The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP : composite piles for load-bearing in bridges. This report covers Task 3, FRP Composite Pile Flexural Testing. : Hollow and concrete filled...
DOT National Transportation Integrated Search
2015-06-01
For years, the Kansas Department of Transportation (KDOT) and concrete producers in the state have used a : Rapid Chloride Test for concrete cylinders, AASHTO T277. This test has been thought of as an appropriate quality : control test to evaluate pe...
Mechanical Properties and Eco-Efficiency of Steel Fiber Reinforced Alkali-Activated Slag Concrete.
Kim, Sun-Woo; Jang, Seok-Joon; Kang, Dae-Hyun; Ahn, Kyung-Lim; Yun, Hyun-Do
2015-10-30
Conventional concrete production that uses ordinary Portland cement (OPC) as a binder seems unsustainable due to its high energy consumption, natural resource exhaustion and huge carbon dioxide (CO₂) emissions. To transform the conventional process of concrete production to a more sustainable process, the replacement of high energy-consumptive PC with new binders such as fly ash and alkali-activated slag (AAS) from available industrial by-products has been recognized as an alternative. This paper investigates the effect of curing conditions and steel fiber inclusion on the compressive and flexural performance of AAS concrete with a specified compressive strength of 40 MPa to evaluate the feasibility of AAS concrete as an alternative to normal concrete for CO₂ emission reduction in the concrete industry. Their performances are compared with reference concrete produced using OPC. The eco-efficiency of AAS use for concrete production was also evaluated by binder intensity and CO₂ intensity based on the test results and literature data. Test results show that it is possible to produce AAS concrete with compressive and flexural performances comparable to conventional concrete. Wet-curing and steel fiber inclusion improve the mechanical performance of AAS concrete. Also, the utilization of AAS as a sustainable binder can lead to significant CO₂ emissions reduction and resources and energy conservation in the concrete industry.
Use of improved structural materials systems in marine piling : interim report.
DOT National Transportation Integrated Search
1982-09-01
This report contains the results of a study to evaluate the feasibility of manufacturing precast, prestressed marine pile from polymer concrete, polymer impregnated concrete, internally sealed concrete and latex modified concrete. Included in the rep...
Laboratory and field evaluation of concrete paving curing effectiveness.
DOT National Transportation Integrated Search
2009-12-01
Ensuring that sufficient water is available in hydrating concrete is of great importance to produce durable : concrete and achieve both short- and long-term performance of concrete pavement. Excessive early-age : evaporation from the surface of concr...
Evaluation of bridge deck with shrinkage-compensating concrete : VCTIR report detail.
DOT National Transportation Integrated Search
2016-01-01
Concrete bridge decks are susceptible to premature cracking and to corrosion of reinforcing steel. Low-permeability concrete does not always ensure durability if the concrete has excessive cracks that facilitate the intrusion of aggressive solutions....
DOT National Transportation Integrated Search
2012-10-01
The main objective of this study was to determine the effect on bond performance : of high-volume fly ash (HVFA) concrete. The HVFA concrete test program consisted of : comparing the bond performance of two concrete mix designs with 70% cement : repl...
DOT National Transportation Integrated Search
2006-08-01
Two types of concrete overlays silica fume concrete (SFC) and latex-modified Type III portland cement concrete (LMC-III) were installed ant tested as part of the Strategic Highway Research Program (SHRP) Project C-206: Optimization of Highway Concret...
Rotaxane and catenane host structures for sensing charged guest species.
Langton, Matthew J; Beer, Paul D
2014-07-15
CONSPECTUS: The promise of mechanically interlocked architectures, such as rotaxanes and catenanes, as prototypical molecular switches and shuttles for nanotechnological applications, has stimulated an ever increasing interest in their synthesis and function. The elaborate host cavities of interlocked structures, however, can also offer a novel approach toward molecular recognition: this Account describes the use of rotaxane and catenane host systems for binding charged guest species, and for providing sensing capability through an integrated optical or electrochemical reporter group. Particular attention is drawn to the exploitation of the unusual dynamic properties of interlocked molecules, such as guest-induced shuttling or conformational switching, as a sophisticated means of achieving a selective and functional sensor response. We initially survey interlocked host systems capable of sensing cationic guests, before focusing on our accomplishments in synthesizing rotaxanes and catenanes designed for the more challenging task of selective anion sensing. In our group, we have developed the use of discrete anionic templation to prepare mechanically interlocked structures for anion recognition applications. Removal of the anion template reveals an interlocked host system, possessing a unique three-dimensional geometrically restrained binding cavity formed between the interlocked components, which exhibits impressive selectivity toward complementary anionic guest species. By incorporating reporter groups within such systems, we have developed both electrochemical and optical anion sensors which can achieve highly selective sensing of anionic guests. Transition metals, lanthanides, and organic fluorophores integrated within the mechanically bonded structural framework of the receptor are perturbed by the binding of the guest, with a concomitant change in the emission profile. We have also exploited the unique dynamics of interlocked hosts by demonstrating that an anion-induced conformational change can be used as a means of signal transduction. Electrochemical sensing has been realized by integration of the redox-active ferrocene functionality within a range of rotaxane and catenanes; binding of an anion perturbs the metallocene, leading to a cathodic shift in the ferrocene/ferrocenium redox couple. In order to obtain practical sensors for target charged guest species, confinement of receptors at a surface is necessary in order to develop robust, reuseable devices. Surface confinement also offers advantages over solution based receptors, including amplification of signal, enhanced guest binding thermodynamics and the negation of solubility problems. We have fabricated anion-templated rotaxanes and catenanes on gold electrode surfaces and demonstrated that the resulting mechanically bonded self-assembled monolayers are electrochemically responsive to the binding of anions, a crucial first step toward the advancement of sophisticated, highly selective, anion sensory devices. Rotaxane and catenane host molecules may be engineered to offer a superior level of molecular recognition, and the incorporation of optical or electrochemical reporter groups within these interlocked frameworks can allow for guest sensing. Advances in synthetic templation strategies has facilitated the synthesis of interlocked architectures and widened their interest as prototype molecular machines. However, their unique host-guest properties are only now beginning to be exploited as a sophisticated approach to chemical sensing. The development of functional host-guest sensory systems such as these is of great interest to the interdisciplinary field of supramolecular chemistry.
Examination of the feasibility of alcohol interlocks for motorcycles.
DOT National Transportation Integrated Search
2017-06-01
In 2011 some 30 percent of the 4,612 motorcycle operators involved in fatal crashes had blood alcohol concentrations : (BACs) of .08 g/dL or higher. Although alcohol ignition interlocks are a common sanction to deter impaired driving, : they are not ...
Laboratory evaluation of recycled concrete as aggregate in new concrete pavements.
DOT National Transportation Integrated Search
2014-09-01
The Washington State Department of Transportation (WSDOT) has initiated a research project to investigate the use of recycled concrete as : aggregates (RCA) in Portland (hydraulic) cement concrete pavements (PCCP). The planned source for the RCA in t...
Evaluation of consolidation problems in thicker Portland cement concrete pavements
DOT National Transportation Integrated Search
2003-08-01
Minimizing the amount of entrapped air in concrete is necessary to produce quality concrete with a longer pavement performance life, lower maintenance costs and fewer delays to the roadway users. Good quality concrete with low entrapped air content w...
Aquaporin-0 Targets Interlocking Domains to Control the Integrity and Transparency of the Eye Lens
Lo, Woo-Kuen; Biswas, Sondip K.; Brako, Lawrence; Shiels, Alan; Gu, Sumin; Jiang, Jean X.
2014-01-01
Purpose. Lens fiber cell membranes contain aquaporin-0 (AQP0), which constitutes approximately 50% of the total fiber cell membrane proteins and has a dual function as a water channel protein and an adhesion molecule. Fiber cell membranes also develop an elaborate interlocking system that is required for maintaining structural order, stability, and lens transparency. Herein, we used an AQP0-deficient mouse model to investigate an unconventional adhesion role of AQP0 in maintaining a normal structure of lens interlocking protrusions. Methods. The loss of AQP0 in AQP0−/− lens fibers was verified by Western blot and immunofluorescence analyses. Changes in membrane surface structures of wild-type and AQP0−/− lenses at age 3 to 12 weeks were examined with scanning electron microscopy. Preferential distribution of AQP0 in wild-type fiber cell membranes was analyzed with immunofluorescence and immunogold labeling using freeze-fracturing transmission electron microscopy. Results. Interlocking protrusions in young differentiating fiber cells developed normally but showed minor abnormalities at approximately 50 μm deep in the absence of AQP0 in all ages studied. Strikingly, protrusions in maturing fiber cells specifically underwent uncontrolled elongation, deformation, and fragmentation, while cells still retained their overall shape. Later in the process, these changes eventually resulted in fiber cell separation, breakdown, and cataract formation in the lens core. Immunolabeling at the light microscopy and transmission electron microscopy levels demonstrated that AQP0 was particularly enriched in interlocking protrusions in wild-type lenses. Conclusions. This study suggests that AQP0 exerts its primary adhesion or suppression role specifically to maintain the normal structure of interlocking protrusions that is critical to the integrity and transparency of the lens. PMID:24458158
Numerical Investigations On The Seismic Behaviour Of Confined Masonry Walls
DOE Office of Scientific and Technical Information (OSTI.GOV)
Calderini, Chiara; Cattari, Serena; Lagomarsino, Sergio
2008-07-08
In the last century, severe earthquakes highlighted the seismic vulnerability of unreinforced masonry buildings. Many technological innovations have been introduced in time in order to improve resistance, ductility, and dissipation properties of this type of constructions. The most widely diffused are reinforced masonry and confined masonry. Damage observation of recent earthquakes demonstrated the effectiveness of the response of confined masonry structures to seismic actions. In general, in this type of structures, reinforced concrete beams and columns are not main structural elements, however, they have the following functions: to confine masonry in order to increase its ductility; to bear tensile stressesmore » derived from bending; to contrast the out-of-plane overturning of masonry panels. It is well evident that these functions are as much effectively performed as the connection between masonry and reinforced concrete elements is good (for example by mean of local interlocking or reinforcements). Confined masonry structures have been extensively studied in the last decades both from a theoretical point of view and by experimental tests Aims of this paper is to give a contribution to the understanding of the seismic behaviour of confined masonry walls by means of numerical parametrical analyses. There latter are performed by mean of the finite element method; a nonlinear anisotropic constitutive law recently developed for masonry is adopted. Comparison with available experimental results are carried out in order to validate the results. A comparison between the resistance obtained from the numerical analyses and the prevision provided by simplified resistance criteria proposed in literature and in codes is finally provided.« less
A Study on the Reuse of Plastic Concrete Using Extended Set-Retarding Admixtures.
Lobo, Colin; Guthrie, William F; Kacker, Raghu
1995-01-01
The disposal of ready mixed concrete truck wash water and returned plastic concrete is a growing concern for the ready mixed concrete industry. Recently, extended set-retarding admixtures, or stabilizers, which slow or stop the hydration of portland cement have been introduced to the market. Treating truck wash-water or returned plastic concrete with stabilizing admixtures delays its setting and hardening, thereby facilitating the incorporation of these typically wasted materials in subsequent concrete batches. In a statistically designed experiment, the properties of blended concrete containing stabilized plastic concrete were evaluated. The variables in the study included (1) concrete age when stabilized, (2) stabilizer dosage, (3) holding period of the treated (stabilized) concrete prior to blending with fresh ingredients, and (4) amount of treated concrete in the blended batch. The setting time, strength, and drying shrinkage of the blended concretes were evaluated. For the conditions tested, batching 5 % treated concrete with fresh material did not have a significant effect on the setting time, strength, or drying shrinkage of the resulting blended concrete. Batching 50 % treated concrete with fresh materials had a significant effect on the setting characteristics of the blended cocnrete, which in turn affected the water demand to maintain slump. The data suggests that for a known set of conditions, the stabilizer dosage can be optimized within a relatively narrow range to produce desired setting characteristics. The strength and drying shrinkage of the blended concretes were essentially a function of the water content at different sampling ages and the relationship followed the general trend of control concrete.
A Study on the Reuse of Plastic Concrete Using Extended Set-Retarding Admixtures
Lobo, Colin; Guthrie, William F.; Kacker, Raghu
1995-01-01
The disposal of ready mixed concrete truck wash water and returned plastic concrete is a growing concern for the ready mixed concrete industry. Recently, extended set-retarding admixtures, or stabilizers, which slow or stop the hydration of portland cement have been introduced to the market. Treating truck wash-water or returned plastic concrete with stabilizing admixtures delays its setting and hardening, thereby facilitating the incorporation of these typically wasted materials in subsequent concrete batches. In a statistically designed experiment, the properties of blended concrete containing stabilized plastic concrete were evaluated. The variables in the study included (1) concrete age when stabilized, (2) stabilizer dosage, (3) holding period of the treated (stabilized) concrete prior to blending with fresh ingredients, and (4) amount of treated concrete in the blended batch. The setting time, strength, and drying shrinkage of the blended concretes were evaluated. For the conditions tested, batching 5 % treated concrete with fresh material did not have a significant effect on the setting time, strength, or drying shrinkage of the resulting blended concrete. Batching 50 % treated concrete with fresh materials had a significant effect on the setting characteristics of the blended cocnrete, which in turn affected the water demand to maintain slump. The data suggests that for a known set of conditions, the stabilizer dosage can be optimized within a relatively narrow range to produce desired setting characteristics. The strength and drying shrinkage of the blended concretes were essentially a function of the water content at different sampling ages and the relationship followed the general trend of control concrete. PMID:29151762
DOT National Transportation Integrated Search
2015-06-01
For years, the Kansas Department of Transportation (KDOT) and concrete producers in : the state have used a Rapid Chloride Test for concrete cylinders, AASHTO T277. This : test has been thought of as an appropriate quality control test to evaluate pe...
DOT National Transportation Integrated Search
1999-06-01
Four bridge decks were overlayed and patched and one bridge pier was patched using concrete with and without corrosion inhibiting admixtures. Some concrete surfaces received topically applied corrosion-inhibiting treatments prior to placement of the ...
Evaluation of Durability Parameters of Concrete with Manufacture Sand and River Sand
NASA Astrophysics Data System (ADS)
Sangoju, Bhaskar; Ramesh, G.; Bharatkumar, B. H.; Ramanjaneyulu, K.
2017-09-01
Most of the states in our country have banned sand quarrying from the river beds, causing a scarcity of natural river sand for the construction sector. Manufacture sand (M-sand) is one of the alternate solutions to replace the river sand (R-sand) in concrete. The main aim of the present study is to evaluate the durability parameters of concrete with M-sand when compared to that of concrete with R-sand. Corrosion of reinforcement is one of the main deteriorating mechanisms of reinforced concrete due to the ingress of chloride ions or carbon-di-oxide. For comparative evaluation of durability parameters, accelerated tests such as Rapid Chloride Permeability Test, Rapid Chloride Migration Test and accelerated carbonation test were carried out on specimens of R-sand and M-sand. All tests were carried out after 90 days of casting. Test results reveal that the durability parameters of the concrete with M-sand in chloride induced environment is relatively better than that of concrete with R-sand and hence is recommended to use M-sand as a replacement to R-sand.
12 CFR 238.91 - Authority, purpose, and scope.
Code of Federal Regulations, 2013 CFR
2013-01-01
... SYSTEM (CONTINUED) SAVINGS AND LOAN HOLDING COMPANIES (REGULATION LL) Management Official Interlocks... situations where the management interlock likely would have an anticompetitive effect. (c) Scope. This... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Authority, purpose, and scope. 238.91 Section...
A Modular Approach for Interlocking Enzymes in Whatman Paper.
Riccardi, Caterina; Kumar, Challa; Kasi, Rajeswari; McCormick, Shelby
2018-06-13
We report a potentially universal approach for enzyme attachment to cellulose that significantly enhances enzyme stability while retaining high activity, and involves no chemical functionalization of cellulose. In our design, bovine serum albumin (BSA) was interlocked in cellulose to form a protein-friendly surface (named BSA-Paper), while also providing COOH and NH2 groups for subsequent attachment of enzymes. The desired enzyme is then mixed with additional BSA and interlocked on BSA-Paper. The 2nd layer dilutes and crosslinks the enzyme for improved stability. Laccase was tested as a model enzyme for interlocking on BSA-Paper, and was found to retain over 100% activity and was 240 times more stable at 25 °C (half life = 180 d) than laccase. This new approach was also tested with a few other enzymes with encouraging results, thus providing a potentially universal method for stabilization of enzymes on cellulose with retention of high activities. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Variable stiffness sandwich panels using electrostatic interlocking core
NASA Astrophysics Data System (ADS)
Heath, Callum J. C.; Bond, Ian P.; Potter, Kevin D.
2016-04-01
Structural topology has a large impact on the flexural stiffness of a beam structure. Reversible attachment between discrete substructures allows for control of shear stress transfer between structural elements, thus stiffness modulation. Electrostatic adhesion has shown promise for providing a reversible latching mechanism for controllable internal connectivity. Building on previous research, a thin film copper polyimide laminate has been used to incorporate high voltage electrodes to Fibre Reinforced Polymer (FRP) sandwich structures. The level of electrostatic holding force across the electrode interface is key to the achievable level of stiffness modulation. The use of non-flat interlocking core structures can allow for a significant increase in electrode contact area for a given core geometry, thus a greater electrostatic holding force. Interlocking core geometries based on cosine waves can be Computer Numerical Control (CNC) machined from Rohacell IGF 110 Foam core. These Interlocking Core structures could allow for enhanced variable stiffness functionality compared to basic planar electrodes. This novel concept could open up potential new applications for electrostatically induced variable stiffness structures.
Evaluation of concrete bridge mix designs for control of cracking, phase I.
DOT National Transportation Integrated Search
2014-11-01
Cracking of concrete is a common problem with concrete structures such as bridge decks, pavements and bridge : rail. The Agency of Transportation (VTrans) has recently invested in higher performing concrete mixes that are : more impervious and has hi...
Evaluating the Effect of Slab Curling on IRI for South Carolina Concrete Pavements
DOT National Transportation Integrated Search
2010-10-01
Concrete pavements are known to curl due to a temperature gradient within the concrete caused by both daily : and seasonal temperature variations. This research project measured the magnitude of concrete pavement slab : curling of two newly construct...
DOT National Transportation Integrated Search
2009-01-01
Part 1Pavement Condition Evaluation, Impact, and Durability; Part 2Concrete Pavement Preservation, Repair, and Rehabilitation; Part 3Concrete Pavement Repair Techniques and Experiences; Part 4Concrete Pavement Surface Texture; Part 5Emergin...
Using recycled concrete as aggregate in concrete pavements to reduce materials cost.
DOT National Transportation Integrated Search
2013-08-01
The main objective of this project was to evaluate the effects of using aggregate produced from crushed concrete pavement as a replacement for natural (virgin) coarse aggregate in pavement mixtures. A total of ten different concrete mixtures containi...
Raj, Manish; Kumar, Sunil; Singh, Pulkesh; Kumar, Dinesh; Singh, Jasveer; Deep, Akash
2016-01-01
Introduction Management of compound grade III fractures of both bone leg includes external stabilization for long period, followed by various soft tissue coverage procedures. Primary interlocking of tibia had been also done with variable results. External fixation for long time without any bone loss often leads to infected nonunion, loss of reduction, pin tract infection and failure of fixation, primary interlocking in compound grade III fractures had shown high medullary infection rate. We managed all cases of compound grade III A/B fractures with primary external fixation, simultaneous wound management using vacuum assisted closure (VAC) followed by early conversion to interlocking within 2 weeks of fixator application. Aim To determine the effectiveness of vacuum assisted closure (VAC) for the early conversion of external fixator to definitive interlocking in open fractures of the both bone leg. Materials and Methods In current study we selected 84 cases of compound grade IIIA/B diaphyseal fractures of both bone leg during period of May 2010 to September 2013. We managed these cases by immediate debridement and application of external fixation followed by repeated debridement, application of vacuum assisted closure (VAC) and conversion to interlocking within two weeks. Results Out of 84 cases union was achieved in 80(95%) of cases with definitive tibial interlocking. Excellent to good result were obtained in 77(91.8%) of cases and fair to poor result seen in rest of 7(8.2%) of cases according to modified Ketenjian’s criteria. 5 out of these 7 poor result group cases were from Compound Grade III B group to start with. Deep infection rate in our series were 7% i.e. total 6 cases and 4 out of these were from compound Grade III B group to start with. Conclusion Vacuum assisted closure (VAC) give a good help for rapid closure of the wound and help in early conversion to definitive intramedullary nailing. Reamed nail could well be used in compound grade IIIA/B fractures without increasing the risk of infection. It gives better stability to fracture site and lessen the risk of implant failure. PMID:27042541
Mechanical Properties and Eco-Efficiency of Steel Fiber Reinforced Alkali-Activated Slag Concrete
Kim, Sun-Woo; Jang, Seok-Joon; Kang, Dae-Hyun; Ahn, Kyung-Lim; Yun, Hyun-Do
2015-01-01
Conventional concrete production that uses ordinary Portland cement (OPC) as a binder seems unsustainable due to its high energy consumption, natural resource exhaustion and huge carbon dioxide (CO2) emissions. To transform the conventional process of concrete production to a more sustainable process, the replacement of high energy-consumptive PC with new binders such as fly ash and alkali-activated slag (AAS) from available industrial by-products has been recognized as an alternative. This paper investigates the effect of curing conditions and steel fiber inclusion on the compressive and flexural performance of AAS concrete with a specified compressive strength of 40 MPa to evaluate the feasibility of AAS concrete as an alternative to normal concrete for CO2 emission reduction in the concrete industry. Their performances are compared with reference concrete produced using OPC. The eco-efficiency of AAS use for concrete production was also evaluated by binder intensity and CO2 intensity based on the test results and literature data. Test results show that it is possible to produce AAS concrete with compressive and flexural performances comparable to conventional concrete. Wet-curing and steel fiber inclusion improve the mechanical performance of AAS concrete. Also, the utilization of AAS as a sustainable binder can lead to significant CO2 emissions reduction and resources and energy conservation in the concrete industry. PMID:28793639
Fan, Wei-Jie; Wang, Xiao-Yong; Park, Ki-Bong
2015-01-01
High-calcium fly ash (FH) is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concrete industry, this paper presents a theoretical model to systematically evaluate the property developments of FH blended concrete. The proposed model analyzes the cement hydration, the reaction of free CaO in FH, and the reaction of phases in FH other than free CaO. The mutual interactions among cement hydration, the reaction of free CaO in FH, and the reaction of other phases in FH are also considered through the calcium hydroxide contents and the capillary water contents. Using the hydration degree of cement, the reaction degree of free CaO in FH, and the reaction degree of other phases in FH, the proposed model evaluates the calcium hydroxide contents, the reaction degree of FH, chemically bound water, porosity, and the compressive strength of hardening concrete with different water to binder ratios and FH replacement ratios. The evaluated results are compared to experimental results, and good consistencies are found. PMID:28793543
DOT National Transportation Integrated Search
2004-12-01
This study evaluates the rehabilitation method utilizing the injection of Uretek (polyurethane) into the pavement structures on continuously reinforced concrete pavement (CRCP), jointed concrete pavement (JCP), and bridge approach slabs. The polyuret...
Laboratory comparison of several tests for evaluating the transport properties of concrete.
DOT National Transportation Integrated Search
2006-01-01
The transport properties of concrete are a primary element in determining the durability of concrete. In this study, several new test methods that directly measure aspects of fluid and ionic transport in concrete were examined. ASTM C 1543 and ASTM C...
Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard
This page contains documents related to the evaluation of coal combustion residual beneficial use of fly ash concrete and FGD gypsum wallboard including the evaluation itself and the accompanying appendices
NASA Astrophysics Data System (ADS)
Ruiko, Watanabe; Toshiaki, Mizobuchi
2017-04-01
Rapid aging of many concrete structures, which have been developed during rapid economic growth period in Japan, has become a serious problem for us these days. And thus, there is an urgent need to prolong their service life expectancies. For this purpose, the deterioration of reinforcing bars in the concrete structures should be detected quickly and correctly at the early stages. Nevertheless, conventional testing methods such as destructive and nondestructive testing have disadvantages: partial damages on concrete structures; difficulty with quantitative evaluation, etc. Many preceding studies have examined to estimate the deterioration of reinforcing bars based on the temperature of the concrete specimen surfaces. According to those papers, the differences in corrosion degree of reinforcing bars have a certain effect on the temperature of concrete specimen surfaces. In this study, firstly, the quantitative evaluation of the corrosion degree was conducted with 3D scanner which could measure the volume, coverage area and cross-sectional area. Secondly, the surface of the concrete specimen was cooled down with liquid nitrogen, and thirdly, thermographic change was observed up until the air temperature. Finally, the surface of the concrete specimen was detected clearly by the thermal images. As a result, this study shows that the corrosion thickness tends to get bigger, following the uprising temperature of the concrete specimen surfaces. The same kind of tendency can be observed by the thermal images, too.
30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motor-starter enclosures; barriers and interlocks. 75.819 Section 75.819 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High...
12 CFR 711.5 - Small market share exemption.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Small market share exemption. 711.5 Section 711.5 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.5 Small market share exemption. (a) Exemption. A management interlock...
Durability of coconut shell powder (CSP) concrete
NASA Astrophysics Data System (ADS)
Leman, A. S.; Shahidan, S.; Senin, M. S.; Shamsuddin, S. M.; Anak Guntor, N. A.; Zuki, S. S. Mohd; Khalid, F. S.; Azhar, A. T. S.; Razak, N. H. S.
2017-11-01
The rising cost of construction in developing countries like Malaysia has led concrete experts to explore alternative materials such as coconut shells which are renewable and possess high potential to be used as construction material. Coconut shell powder in varying percentages of1%, 3% and 5% was used as filler material in concrete grade 30 and evaluated after a curing period of 7 days and 28days respectively. Compressive strength, water absorption and carbonation tests were conducted to evaluate the strength and durability of CSP concrete in comparison with normal concrete. The test results revealed that 1%, 3% and 5% of CSP concrete achieved a compressive strength of 47.65 MPa, 45.6 MPa and 40.55% respectively. The rate of water absorption of CSP concrete was recorded as 3.21%, 2.47%, and 2.73% for 1%, 3% and 5% of CSP concrete respectively. Although CSP contained a carbon composition of 47%, the carbonation test showed that CSP no signs of carbon were detected inside the concrete. To conclude, CSP offers great prospects as it demonstrated relatively high durability as a construction material.
I-SonReb: an improved NDT method to evaluate the in situ strength of carbonated concrete
NASA Astrophysics Data System (ADS)
Breccolotti, Marco; Bonfigli, Massimo F.
2015-10-01
Concrete strength evaluated in situ by means of the conventional SonReb method can be highly overestimated in presence of carbonation. This latter, in fact, is responsible for the physical and chemical alteration of the outer layer of concrete. As most of the existing concrete structures are subjected to carbonation, it is of high importance to overcome this problem. In this paper, an Improved SonReb method (I-SonReb) for carbonated concretes is proposed. It relies on the definition of a correction coefficient of the measured Rebound index as a function of the carbonated concrete cover thickness, an additional parameter to be measured during in situ testing campaigns. The usefulness of the method has been validated showing the improvement in the accuracy of concrete strength estimation from two sets of NDT experimental data collected from investigations on real structures.
DOT National Transportation Integrated Search
2012-11-01
Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...
Yang, Linlin; Jing, Xu; An, Bowen; Yang, Yang
2017-01-01
By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system. PMID:29675152
Witherby, Amber E; Tauber, Sarah K
2017-05-01
Researchers have often determined how cues influence judgments of learning (JOLs; e.g., concrete words are assigned higher JOLs than are abstract words), and recently there has been an emphasis in understanding why cues influence JOLs (i.e., the mechanisms that underlie cue effects on JOLs). The analytic-processing (AP) theory posits that JOLs are constructed in accordance with participants' beliefs of how a cue will influence memory. Even so, some evidence suggests that fluency is also important to cue effects on JOLs. In the present experiments, we investigated the contributions of participants' beliefs and processing fluency to the concreteness effect on JOLs. To evaluate beliefs, participants estimated memory performance in a hypothetical experiment (Experiment 1), and studied concrete and abstract words and made a pre-study JOL for each (Experiments 2 and 3). Participants' predictions demonstrated the belief that concrete words are more likely to be remembered than are abstract words, consistent with the AP theory. To evaluate fluency, response latencies were measured during lexical decision (Experiment 4), self-paced study (Experiment 5), and mental imagery (Experiment 7). Number of trials to acquisition was also evaluated (Experiment 6). Fluency did not differ between concrete and abstract words in Experiments 5 and 6, and it did not mediate the concreteness effect on JOLs in Experiments 4 and 7. Taken together, these results demonstrate that beliefs are a primary mechanism driving the concreteness effect on JOLs.
DOT National Transportation Integrated Search
2015-10-01
Diamond grinding is a concrete pavement restoration technique that corrects irregularities : such as faulting and roughness on old concrete pavements and extends the life of pavement. : Cooling water used during the diamond grinding of concrete pavem...
46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.
Code of Federal Regulations, 2011 CFR
2011-10-01
... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...
46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.
Code of Federal Regulations, 2014 CFR
2014-10-01
... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...
46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.
Code of Federal Regulations, 2013 CFR
2013-10-01
... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...
46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.
Code of Federal Regulations, 2012 CFR
2012-10-01
... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...
46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.
Code of Federal Regulations, 2010 CFR
2010-10-01
... difference in potential between the external conductors, overcurrent protection need only be at the supply of... to start. (c) Source of potential. The potential for a control, interlock, or indicator circuit must... disconnected from all sources of potential by a disconnect device independent of the motor and controller...
12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Federal Deposit Insurance Corporation pursuant to section 13(k)(1)(A)(v) of the Federal Deposit Insurance Act, as amended (12 U.S.C. 1823(k)(1)(A)(v)). ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Interlocking relationships permitted pursuant...
12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Federal Deposit Insurance Corporation pursuant to section 13(k)(1)(A)(v) of the Federal Deposit Insurance Act, as amended (12 U.S.C. 1823(k)(1)(A)(v)). ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Interlocking relationships permitted pursuant...
12 CFR 212.5 - Small market share exemption.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Small market share exemption. 212.5 Section 212.5 Banks and Banking FEDERAL RESERVE SYSTEM BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.5 Small market share exemption. (a) Exemption. A management interlock...
Thomas L. Eberhardt; Karen G. Reed
2006-01-01
Southern yellow pine bark was obtained from an industrial source and subjected to grinding and classification operations to ultimately afford finely ground bark fractions for evaluation as plywood adhesive mix fillers. Specifically, by grinding in a laboratory blender, we were able to generate a bark fraction rich in periderm tissue with its interlocking spiculate...
A field investigation of a concrete overlay containing silica fume on Route 50 over Opequon Creek.
DOT National Transportation Integrated Search
1993-01-01
This study evaluated concretes containing silica fume for use in overlays as a suitable alternative to the widely used latex-modified concrete (LMC). A two-lane, four-span bridge deck was overlaid with concrete containing silica fume at 7 percent or ...
DOT National Transportation Integrated Search
2012-10-01
The main objective of this study was to determine the effect on shrinkage, creep, : and abrasion resistance of high-volume fly ash (HVFA) concrete. The HVFA concrete : test program consisted of comparing the shrinkage, creep, and abrasion performance...
Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures
NASA Technical Reports Server (NTRS)
Jones, Justin S.; Polis, Daniel L.; Segal, Kenneth N.
2011-01-01
The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to traditionally manufactured barrel segments. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the z-fiber weave to a fully interlocked weave with comparable fiber bias, the z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.
The evaluation of pavement patching materials in Oregon : final report.
DOT National Transportation Integrated Search
1980-11-01
This report describes the installation and evaluation of trial pavement patching materials in Oregon. The patches were placed in Portland cement concrete and bituminous concrete pavements and evaluated for periods ranging from four to twelve months. ...
Tam, Vivian W Y; Tam, Leona; Le, Khoa N
2010-02-01
Waste management is pressing very hard with alarming signals in construction industry. Concrete waste constituents major proportions of construction and demolition waste of 81% in Australia. To minimize concrete waste generated from construction activities, recycling concrete waste is one of the best methods to conserve the environment. This paper investigates concrete recycling implementation in construction. Japan is a leading country in recycling concrete waste, which has been implementing 98% recycling and using it for structural concrete applications. Hong Kong is developing concrete recycling programs for high-grade applications. Australia is making relatively slow progress in implementing concrete recycling in construction. Therefore, empirical studies in Australia, Hong Kong, and Japan were selected in this paper. A questionnaire survey and structured interviews were conducted. Power spectrum was used for analysis. It was found that "increasing overall business competitiveness and strategic business opportunities" was considered as the major benefit for concrete recycling from Hong Kong and Japanese respondents, while "rising concrete recycling awareness such as selecting suitable resources, techniques and training and compliance with regulations" was considered as the major benefit from Australian respondents. However, "lack of clients' support", "increase in management cost" and "increase in documentation workload, such as working documents, procedures and tools" were the major difficulties encountered from Australian, Hong Kong, and Japanese respondents, respectively. To improve the existing implementation, "inclusion of concrete recycling evaluation in tender appraisal" and "defining clear legal evaluation of concrete recycling" were major recommendations for Australian and Hong Kong, and Japanese respondents, respectively.
Evaluation of Blast Resistance of Fiber Reinforced Composite Specimens under Contact Blast Load
NASA Astrophysics Data System (ADS)
Janota, O.; Foglar, M.
2017-09-01
This paper presents results of experimental programme which took place in 2014, 2015 and 2016. Experiments were focused on the resistance of full scale concrete panels subjected to contact blast loading. Specimens were loaded by contact blast by plastic explosive. All specimens were reinforced concrete slabs made of fiber concrete. Basalt mesh and textile sheets were added to some of the experiments for creating more heterogeneous material to achieve better resistance of the specimens. Evaluation of experiments was mainly focused on the damaged area on the contact side and soffit of the specimens. Dependency of the final damage of concrete panels on the weight of explosive and concrete strength was assessed.
NASA Astrophysics Data System (ADS)
Gholamhoseini, Alireza
2018-03-01
Composite one-way concrete slabs with profiled steel decking as permanent formwork are commonly used in the construction industry. The steel decking supports the wet concrete of a cast in situ reinforced or post-tensioned concrete slab and, after the concrete sets, acts as external reinforcement. In this type of slab, longitudinal shear failure between the concrete and the steel decking is the most common type of failure at the ultimate load stage. Design codes require the experimental evaluation of the ultimate load capacity and longitudinal shear strength of each type of steel decking using full-scale tests on simple-span slabs. There is also no procedure in current design codes to evaluate the ultimate load capacity and longitudinal shear strength of continuous composite slabs and this is often assessed experimentally by full-scale tests. This paper presents the results of three full-scale tests up to failure on continuous composite concrete slabs cast with trapezoidal steel decking profile (KF70) that is widely used in Australia. Slab specimens were tested in four-point bending at each span with shear spans of span/4. The longitudinal shear failure of each slab is evaluated and the measured mid-span deflection, the end slip and the mid-span steel and concrete strains are also presented and discussed. Redistribution of bending moment in each slab is presented and discussed. A finite element model is proposed and verified by experimental data using interface element to model the bond properties between steel decking and concrete slab and investigate the ultimate strength of continuous composite concrete slabs.
Interlocking intramedullary nailing in distal tibial fractures.
Tyllianakis, M; Megas, P; Giannikas, D; Lambiris, E
2000-08-01
This retrospective study examined the results of non-pilon fractures of the distal part of the tibia treated with interlocking intramedullary nailing. Seventy-three patients with equal numbers of fractures treated surgically between 1990 and 1998 were reviewed. Mean patient age was 39.8 years, and follow-up averaged 34.2 months. The AO fracture classification system was used. Concomitant fractures of the lateral malleolus were fixed. All but three fractures achieved union within 4.2 months on average. Satisfactory or excellent results were obtained in 86.3% of patients. These results indicate interlocking intramedullary nailing is a reliable method of treatment for these fractures and is characterized by high rates of union and a low incidence of complications.
Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements
Hufenbach, Werner; Adam, Frank; Heber, Thomas; Weckend, Nico; Bach, Friedrich-Wilhelm; Hassel, Thomas; Zaremba, David
2011-01-01
Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair. PMID:28824134
Manifold seal structure for fuel cell stack
Collins, William P.
1988-01-01
The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.
Concrete probe-strength study : final report.
DOT National Transportation Integrated Search
1969-12-01
The Windsor probe - test system was evaluated for determining compressive strength of concrete by comparing probe strengths against cylinder and core strengths from both laboratory and field-poured concrete. Advantages and disadvantages of this syste...
Evaluating Pavement Design Features: Five Year Performance Evaluation of FA 401 and FA 409
DOT National Transportation Integrated Search
1993-02-01
In the summer of 1986, the Illinois Department of Transportation began the construction of four demonstration projects which focused on evaluating proposed mechanistically-based asphalt concrete (AC) and Portland cement concrete (PCC) pavement design...
Evaluation of Geosynthetics in Asphalt Overlays of Jointed Concrete Pavements
DOT National Transportation Integrated Search
2000-06-01
This report presents the findings and recommendations based on the Evaluation of Geosynthetics in Asphalt Overlays of Jointed Concrete Pavements. This project evaluated Linq Tac-711N and Strata Grid-200's ability to ease distress and reflective crack...
DOT National Transportation Integrated Search
2011-01-01
The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...
Code of Federal Regulations, 2011 CFR
2011-10-01
... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic... 49 Transportation 4 2011-10-01 2011-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations...
ERIC Educational Resources Information Center
Llamazares, Ivan
2005-01-01
This article explores how the interlocking of formal and informal political institutions has affected the dynamics and performance of the Argentine democracy. Key institutional features of the Argentine political system have been a competitive form of federalism, loosely structured and political parties that are not ideologically unified,…
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical locking removed or disarranged... § 236.326 Mechanical locking removed or disarranged; requirement for permitting train movements through interlocking. When mechanical locking of interlocking machine is being changed or is removed from the machine...
DOT National Transportation Integrated Search
2011-01-01
The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...
Code of Federal Regulations, 2010 CFR
2010-10-01
... automatic interlocking. (a) The control circuits for aspects with indications more favorable than “proceed... 49 Transportation 4 2010-10-01 2010-10-01 false Signal control circuits, selection through track... automatic interlocking. 236.311 Section 236.311 Transportation Other Regulations Relating to Transportation...
12 CFR 26.5 - Small market share exemption.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Small market share exemption. 26.5 Section 26.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.5 Small market share exemption. (a) Exemption. A management interlock that is prohibited by § 26.3...
12 CFR 563f.5 - Small market share exemption.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Small market share exemption. 563f.5 Section 563f.5 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 563f.5 Small market share exemption. (a) Exemption. A management interlock that is prohibited by...
Reviewed approach to defining the Active Interlock Envelope for Front End ray tracing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seletskiy, S.; Shaftan, T.
To protect the NSLS-II Storage Ring (SR) components from damage from synchrotron radiation produced by insertion devices (IDs) the Active Interlock (AI) keeps electron beam within some safe envelope (a.k.a Active Interlock Envelope or AIE) in the transverse phase space. The beamline Front Ends (FEs) are designed under assumption that above certain beam current (typically 2 mA) the ID synchrotron radiation (IDSR) fan is produced by the interlocked e-beam. These assumptions also define how the ray tracing for FE is done. To simplify the FE ray tracing for typical uncanted ID it was decided to provide the Mechanical Engineering groupmore » with a single set of numbers (x,x’,y,y’) for the AIE at the center of the long (or short) ID straight section. Such unified approach to the design of the beamline Front Ends will accelerate the design process and save valuable human resources. In this paper we describe our new approach to defining the AI envelope and provide the resulting numbers required for design of the typical Front End.« less
DOT National Transportation Integrated Search
2001-07-01
This work pertains to preparation of concrete drying shrinkage data for proposed concrete mixtures during normal concrete : trial batch verification. Selected concrete mixtures will include PennDOT Classes AAA and AA and will also include the use of ...
Evaluating the strength of concrete structure on terrace houses
NASA Astrophysics Data System (ADS)
Hasbullah, Mohd. Amran; Yusof, Rohana; Rahman, Mohd Nazaruddin Yusoff @ Abdul
2016-08-01
The concrete structure is the main component to support the structure of the building, but when concrete has been used for an extended period hence, it needs to be evaluated to determine the current strength, durability and how long it can last. The poor quality of concrete structures will cause discomfort to the user and, the safety will be affected due to lack of concrete strength. If these issues are not monitored or not precisely known performance, and no further action done then, the concrete structure will fail and eventually it will collapse. Five units of terrace houses that are built less than 10 years old with extension or renovations and have cracks at Taman Samar Indah, Samarahan, Sarawak have been selected for this study. The instrument used in this research is Ultrasonic Pulse Velocity (UPV), with the objective to determine the current strength and investigate the velocity of a pulse at the concrete cracks. The data showed that the average velocity of the pulse is less than 3.0 km/s and has shown that the quality of the concrete in the houses too weak scale / doubt in the strength of concrete. It also indicates that these houses need to have an immediate repair in order to remain secure other concrete structures.
Recycling of rubble from building demolition for low-shrinkage concretes.
Corinaldesi, Valeria; Moriconi, Giacomo
2010-04-01
In this project concrete mixtures were prepared that were characterized by low ductility due to desiccation by using debris from building demolition, which after a suitable treatment was used as aggregate for partial replacement of natural aggregates. The recycled aggregate used came from a recycling plant, in which rubble from building demolition was selected, crushed, cleaned, sieved, and graded. Such aggregates are known to be more porous as indicated by the Saturated Surface Dry (SSD) moisture content. The recycled concrete used as aggregates were added to the concrete mixture in order to study their influence on the fresh and hardened concrete properties. They were added either after water pre-soaking or in dry condition, in order to evaluate the influence of moisture in aggregates on the performance of concrete containing recycled aggregate. In particular, the effect of internal curing, due to the use of such aggregates, was studied. Concrete behavior due to desiccation under dehydration was studied by means of both drying shrinkage test and German angle test, through which shrinkage under the restrained condition of early age concrete can be evaluated. Copyright 2009 Elsevier Ltd. All rights reserved.
Type A polymer concrete overlay field trials : final report.
DOT National Transportation Integrated Search
1984-12-01
This report describes placement and subsequent performance of two methyl methacrylate polymer concrete overlays. Performance is evaluated as to: 1) the mixing and placement characteristics of the methyl methacrylate polymer concretes as overlay mater...
Tests for early acceptance of concrete.
DOT National Transportation Integrated Search
1985-01-01
A literature survey and limited study of laboratory concretes were conducted to evaluate various methods for predicting concrete strengths at 28 days based on procedures for accelerated strength development or measurement of strength of normally cure...
Roller compacted concrete : field evaluation and mixture optimization.
DOT National Transportation Integrated Search
2014-08-01
Roller Compacted Concrete (RCC) as an economical, fast construction and sustainable materials has attracted increasing attention for pavement construction. The growth of roller-compacted concrete pavement used in different regions is impeded by conce...
A corrosion monitoring system for existing reinforced concrete structures.
DOT National Transportation Integrated Search
2015-05-01
This study evaluated a multi-parameter corrosion monitoring system for existing reinforced concrete structures in chloride-laden service environments. The system was fabricated based on a prototype concrete corrosion measurement system that : had bee...
Utilizing Coal Fly Ash and Recycled Glass in Developing Green Concrete Materials
DOT National Transportation Integrated Search
2012-06-01
The environmental impact of Portland cement concrete production has motivated researchers and the construction industry to evaluate alternative technologies for incorporating recycled cementing materials and recycled aggregates in concrete. One such ...
Evaluation of rubblization project in Ohio : executive summary report.
DOT National Transportation Integrated Search
2011-03-01
Concrete pavements are highly susceptible to variations in temperature. During summer months, the concrete pavements expand and, contract during winter months. Such movements, particularly at the joints in concrete pavements during winter months, exe...
DOT National Transportation Integrated Search
2000-01-01
Three nondestructive evaluation (NDE) methods for concrete pavements - surface ultrasonic pulse velocity measurements (UPV), the impact-echo (IE) method, and the use of a seismic pavement analyzer (SPA) - were tested on six sections of two continuous...
A case study evaluation of the use of video technology in concrete pavement evaluation.
DOT National Transportation Integrated Search
2000-01-01
This report presents the results of an evaluation of video technology as a possible solution to the problem of safely collecting objective condition data for prioritizing concrete pavement rehabilitation needs in Virginia. The study involved the eval...
NASA Astrophysics Data System (ADS)
Su, Yu-Min; Hou, Tsung-Chin; Chen, Guan-Ying; Hou, Ping-Ni
2017-04-01
The research objective was to evaluate Ordinary Portland Cement concrete subject to various elevated temperatures. Single OPC concrete mixture with water to cementitious (w/c) equal to 0.45 was proportioned. Concrete specimens were cast and placed in the curing tank in which water was saturated with calcium hydroxide. After ninety days of moist-cure, three elevated temperatures, namely 300, 600, and 900-°C, were carried out upon hardened concrete specimens. Furthermore, two post-damaged curing conditions were executed to recover damaged concrete specimens: one was to recure under 23°C with 50% humidity in a controlled environmental chamber and the other was to recure in the same curing tank. Acoustic emission apparatus coupled with the splitting tensile test was utilized and found able to assess damaged concrete. Before concrete subject to elevated temperatures, the development of indirect tensile strength versus displacement diagram fit well with the tendency of AE energy release. It was found there was a large amount of AE energy released when stress and displacement diagram developed about 40-50%. As such could be identified as the onset of first fracture and the plain concrete generally exhibited a quasi-brittle fracture with two major series of AE energy dissipations; however when concrete specimens were subject to elevated temperatures, the damaged concrete specimens displayed neither fracture pattern nor the "double-hump" AE energy dissipation in comparison with those of plain concrete.
Nanoarmoring of Enzymes by Interlocking in Cellulose Fibers With Poly(Acrylic Acid).
Riccardi, Caterina M; Kasi, Rajeswari M; Kumar, Challa V
2017-01-01
A simple method for interlocking glucose oxidase (GOx) and horseradish peroxidase (HRP) in cellulose fibers using poly(acrylic acid) (PAA) as an armor around the enzyme, without any need for activation of the cellulose support, is reported here. The resulting enzyme paper is an inexpensive, stable, simple, wearable, and washable biosensor. PAA functions as a multifunctional tether to interlock the enzyme molecules around the paper fibers so that the enzymes are protected against thermal/chemical denaturation and not released from the paper when washed with a detergent. The decreased conformational entropy of the interlocked enzyme protected by the nanoarmor is likely responsible for increased enzyme stability to heat and chemical denaturants (retained ≥70 percent enzyme activity after washing with urea or SDS for 30min), and the polymer protects the enzyme against inactivation by proteases, bacteria, inhibitors, etc. The kinetics of the interlocked enzyme were similar to that of the enzyme in solution. The V max was 6(±0.5)mM per minute before washing, then increased slightly to 9(±1.4)mM per minute after washing with water. The K m was 22(±6.4mM), which was slightly higher compared to GOx in solution (25-27mM). Because the surface area of the paper does not limit the enzyme loading, about 20% of enzyme was successfully loaded onto the paper (0.2g enzyme per gram of paper), and ≥95% of the enzyme was retained after washing. Interlocking works with other enzymes such as laccase, where ≥60% of the enzyme activity is retained. This novel methodology provides a low cost, simple, modular approach of achieving high enzyme loadings in ordinary filter paper, not limited by cellulose surface area, and there has been no need for complex methods of enzyme engineering or toxic methods of activation of the solid support to prepare highly active biocatalysts. © 2017 Elsevier Inc. All rights reserved.
Thick Concrete Specimen Construction, Testing, and Preliminary Analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clayton, Dwight A.; Hoegh, Kyle; Khazanovich, Lev
The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the variousmore » nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations. A preliminary report detailed some of the challenges associated with thick reinforced concrete sections and prioritized conceptual designs of specimens that could be fabricated to represent NPP concrete structures for using in NDE evaluation comparisons. This led to the construction of the concrete specimen presented in this report, which has sufficient reinforcement density and cross-sectional size to represent an NPP containment wall. Details on how a suitably thick concrete specimen was constructed are presented, including the construction materials, final nominal design schematic, as well as formwork and rigging required to safely meet the desired dimensions of the concrete structure. The report also details the type and methods of forming the concrete specimen as well as information on how the rebar and simulated defects were embedded. Details on how the resulting specimen was transported, safely anchored, and marked to allow access for systematic comparative NDE testing of defects in a representative NPP containment wall concrete specimen are also given. Data collection using the MIRA Ultrasonic NDE equipment and initial results are also presented along with a discussion of the preliminary findings. Comparative NDE of various defects in reinforced concrete specimens is a key component in identifying the most promising techniques and directing the research and development efforts needed to characterize concrete degradation in commercial NPPs. This requires access to the specimens for data collection using state-of-the-art technology. The construction of the specimen detailed in this report allows for an evaluation of how different NDE techniques may interact with the size and complexities of NPP concrete structures. These factors were taken into account when determining specimen size and features to ensure a realistic design. The lateral dimensions of the specimen were also chosen to mitigate unrealistic boundary effects that would not affect the results of field NPP concrete testing. Preliminary results show that, while the current methods are able to identify some of the deeper defects, improvements in data processing or hardware are necessary to be able to achieve the precision and reliability achieved in evaluating thinner and less heavily reinforced concrete structures.« less
Time dependent variation of carrying capacity of prestressed precast beam
NASA Astrophysics Data System (ADS)
Le, Tuan D.; Konečný, Petr; Matečková, Pavlína
2018-04-01
The article deals with the evaluation of the precast concrete element time dependent carrying capacity. The variation of the resistance is inherited property of laboratory as well as in-situ members. Thus the specification of highest, yet possible, laboratory sample resistance is important with respect to evaluation of laboratory experiments based on the test machine loading capabilities. The ultimate capacity is evaluated through the bending moment resistance of a simply supported prestressed concrete beam. The probabilistic assessment is applied. Scatter of random variables of compressive strength of concrete and effective height of the cross section is considered. Monte Carlo simulation technique is used to investigate the performance of the cross section of the beam with changes of tendons’ positions and compressive strength of concrete.
1994-02-01
ash, silica-fume, polymer -modified, polymer , and fiber - reinforced concretes. For some nonstructural repairs, unbonded overlays have been employed in an...which silica fume was included; polymer -modified concrete overlay, one in which a polymer admixture had been included; and fiber - reinforced concrete...of pumps. However, a determination has not been made for the source of leakage. 56 Chapter 6 Polymer -Modified Concrete Overlays 7 Fiber - Reinforced
Systems Study of Precast Concrete Tunnel Liners
DOT National Transportation Integrated Search
1975-03-01
The study addresses precast concrete lining systems. Existing precast concrete systems designed or constructed in Europe, Japan, and the United States are evaluated. With these as a point of departure, designs for lining systems applicable to the spe...
Internally cured concrete for pavement and bridge deck applications.
DOT National Transportation Integrated Search
2015-07-01
A laboratory and field testing program was conducted to evaluate the performance and usability of internally : cured concrete (ICC) using lightweight aggregates for bridge decks and concrete pavement slabs under Florida : conditions. The laboratory t...
Evaluation of a thin-bonded Portland cement concrete pavement overlay.
DOT National Transportation Integrated Search
1996-01-01
This report discusses the performance of the Virginia Department of Transportation's first modern rehabilitation project involving a thin-bonded portland cement concrete overlay of an existing jointed concrete pavement. The performance of the rigid o...
Portland-cement concrete rheology and workability : final report.
DOT National Transportation Integrated Search
2011-04-01
Methods for determining the workability of freshly mixed Portland-cement concrete with : slumps less than 5 1 mm (2 in) were investigated. Four potential methods to determine the : workability of concrete were proposed for evaluation and development....
Diagnostic evaluation and repair of deteriorated concrete bridges.
DOT National Transportation Integrated Search
2004-12-01
Concrete bridge deck degradation has been observed in several bridges located in north Mississippi. In this study a : survey was conducted to collect and document instances of deterioration in concrete bridges located throughout the State. The : main...
Investigation of concrete sealer products to extend concrete pavement life : phase 1.
DOT National Transportation Integrated Search
2011-12-01
Five surface applied concrete sealer treatments were evaluated in the laboratory for water vapor transmission, saltwater absorption, alkali resistance, depth of penetration, UV exposure and cyclic saltwater ponding, chloride content, and freeze-thaw ...
APPLICATION OF FLOW SIMULATION FOR EVALUATION OF FILLING-ABILITY OF SELF-COMPACTING CONCRETE
NASA Astrophysics Data System (ADS)
Urano, Shinji; Nemoto, Hiroshi; Sakihara, Kohei
In this paper, MPS method was applied to fluid an alysis of self-compacting concrete. MPS method is one of the particle method, and it is suitable for the simulation of moving boundary or free surface problems and large deformation problems. The constitutive equation of self-compacting concrete is assumed as bingham model. In order to investigate flow Stoppage and flow speed of self-compacting concrete, numerical analysis examples of slump flow and L-flow test were performed. In addition, to evaluate verification of compactability of self-compacting concrete, numerical analys is examples of compaction at the part of CFT diaphragm were performed. As a result, it was found that the MPS method was suitable for the simulation of compaction of self-compacting concrete, and a just appraisal was obtained by setting shear strain rate of flow-limit πc and limitation point of segregation.
Material Concerns: Evaluating Sulfur Concrete for use in the Lunar Environment
NASA Technical Reports Server (NTRS)
Grugel, Richard N.; Toutanji, Houssam
2006-01-01
On Earth sulfur "concrete" is an established construction material that has good mechanical properties, generally better than Portland cement, and can be used in corrosive environments. Troilite (FeS) has been found on the moon and raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. Troilite reduction to elemental sulfur and using it to make concrete in a lunar setting has been previously discussed. However, little has been experimentally done to evaluate its performance in the extreme lunar environment. This study subjected sets of sulfur concrete samples, prepared using JSC-1 lunar simulant, to I ) extended periods of high vacuum and 2) extreme temperature cycles. Here an overview of sulfur concrete and experimentally assessed properties, put in context of the lunar environment, is presented and discussed.
A technical report on structural evaluation of the Meade County reinforced concrete bridge.
DOT National Transportation Integrated Search
2009-01-01
This is a technical report on the first phase of the evaluation of the Meade County reinforced concrete bridge. : The first three chapters introduce the main problem and provide a general review of the existing evaluation : methods and the procedures...
1991-03-01
Vicksburg, MS 39180-6199 REMR-GT-15 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10 . SPONSORINGIMONITORING AGENCY REPORT NUMBER US Army Corps...6 PART II: LITERATURE REVIEW ............................................. 10 General Observations of Recent...Plastic Concrete Research ......... 10 Major Plastic Concrete Research Programs ............................ 13 Plastic Concrete Cutoff Wall Field Case
ERIC Educational Resources Information Center
Melaku, Samuel; Schreck, James O.; Griffin, Kameron; Dabke, Rajeev B.
2016-01-01
Interlocking toy building blocks (e.g., Lego) as chemistry learning modules for blind and visually impaired (BVI) students in high school and undergraduate introductory or general chemistry courses are presented. Building blocks were assembled on a baseplate to depict the relative changes in the periodic properties of elements. Modules depicting…
Code of Federal Regulations, 2010 CFR
2010-10-01
... drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). 1242.58 Section 1242.58... Operating signals and interlockers, operating drawbridges, highway crossing protection (accounts XX-51-59, XX-51-60 and XX-51-61). Separate common expenses on the basis of total train hours (including train...
Using Interlocking Toy Building Blocks to Assess Conceptual Understanding in Chemistry
ERIC Educational Resources Information Center
Geyer, Michael J.
2017-01-01
A current emphasis on teaching conceptual chemistry via the particulate nature of matter has led to the need for new, effective ways to assess students' conceptual understanding of this view of chemistry. This article provides a simple, inexpensive way to use interlocking toy building blocks (e.g., LEGOs) in both formative and summative…
12 CFR 348.4 - Interlocking relationships permitted by statute.
Code of Federal Regulations, 2014 CFR
2014-01-01
... authorized on an emergency basis in accordance with section 13(k) of the Federal Deposit Insurance Act (12 U... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Interlocking relationships permitted by statute... function; (b) A corporation operating under section 25 or section 25A of the Federal Reserve Act (12 U.S.C...
12 CFR 348.4 - Interlocking relationships permitted by statute.
Code of Federal Regulations, 2013 CFR
2013-01-01
... authorized on an emergency basis in accordance with section 13(k) of the Federal Deposit Insurance Act (12 U... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Interlocking relationships permitted by statute... function; (b) A corporation operating under section 25 or section 25A of the Federal Reserve Act (12 U.S.C...
12 CFR 348.4 - Interlocking relationships permitted by statute.
Code of Federal Regulations, 2012 CFR
2012-01-01
... authorized on an emergency basis in accordance with section 13(k) of the Federal Deposit Insurance Act (12 U... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Interlocking relationships permitted by statute... function; (b) A corporation operating under section 25 or section 25A of the Federal Reserve Act (12 U.S.C...
12 CFR 348.4 - Interlocking relationships permitted by statute.
Code of Federal Regulations, 2011 CFR
2011-01-01
... authorized on an emergency basis in accordance with section 13(k) of the Federal Deposit Insurance Act (12 U... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Interlocking relationships permitted by statute... function; (b) A corporation operating under section 25 or section 25A of the Federal Reserve Act (12 U.S.C...
10. General view of site showing south side of Shell ...
10. General view of site showing south side of Shell Interlocking Tower and slope of railroad bed. View to north from unpaved service road extending from Bartels Place. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY
Code of Federal Regulations, 2010 CFR
2010-04-01
... the appropriate TTB officer. Applications for such permission to take office must be prepared and... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Application for approval... Beer § 70.416 Application for approval of interlocking directors and officers under section 8 of the...
Quick-Change Optical-Filter Holder
NASA Technical Reports Server (NTRS)
Leone, Peter
1988-01-01
Dark slide and interlock protect against ambient light. Quick-change filter holder contains interlocking mechanism preventing simultaneous removal of both dark slide and filter drawer. Designed for use with Band pass optical filters in 10 channels leading to photomultiplier tubes in water-vapor lidar/ozone instrument, mechanism can be modified to operate in other optical systems requiring optical change in filters.
Premature deterioration of jointed plain concrete pavements.
DOT National Transportation Integrated Search
2011-04-29
Six sections of jointed plain concrete pavements (JPCP)s throughout the state were selected as candidates for the evaluation of premature deterioration. The data used in performing the evaluation included manual and historic automated distress survey...
Premature deterioration of jointed plain concrete pavements.
DOT National Transportation Integrated Search
2011-04-29
Six sections of jointed plain concrete pavements (JPCP)s throughout the state were selected as : candidates for the evaluation of premature deterioration. The data used in performing the evaluation included manual : and historic automated distress su...
Evaluation of resistivity meters for concrete quality assurance : [research summary].
DOT National Transportation Integrated Search
2015-07-01
This research evaluated a series of MoDOT : concrete mixtures to verify existing : relationships between surface resistivity (SR), : rapid chloride permeability (RCP), chloride ion : diffusion, and the AASHTO penetrability : classes. The research als...
Evaluation of resistivity meters for concrete quality assurance.
DOT National Transportation Integrated Search
2015-06-01
This research evaluated a series of MoDOT concrete mixtures to verify existing relationships between surface resistivity (SR), rapid : chloride permeability (RCP), chloride ion diffusion, and the AASHTO penetrability classes. The research also perfor...
Drake, Jennifer; Bradford, Andrea; Van Seters, Tim
2014-06-15
This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. Copyright © 2014 Elsevier Ltd. All rights reserved.
Development of a device to evaluate the cracking potential of concrete mixtures.
DOT National Transportation Integrated Search
2011-08-01
Developments in material technology during past decades, including the introduction of a wide range of : concrete mixtures, ingredients, and combinations, led to the development of high-performance concrete : (HPC). However, despite advances in techn...
Performance of the first structure built with high performance concrete in Virginia.
DOT National Transportation Integrated Search
2001-08-01
This study evaluated the preparation and placement operations, concrete properties, cost-effectiveness, and performance over 5 years of the first bridge containing high performance concrete built by the Virginia Department of Transportation. High per...
Laboratory fatigue evaluation of continuously fiber-reinforced concrete pavement.
DOT National Transportation Integrated Search
2013-09-01
Portland cement concrete (PCC) is the worlds most versatile construction material. PCC has : been in use in the United States for over 100 years. PCC pavement is generally constructed as : either continually reinforced concrete pavement (CRCP) or ...
Diagnostic evaluation and repair of deteriorated concrete bridges
DOT National Transportation Integrated Search
2004-12-01
Concrete bridge deck degradation has been observed in several bridges located in north Mississippi. In this study a survey was conducted to collect and document instances of deterioration in concrete bridges located throughout the State. The main cau...
Application of self-consolidating concrete in bridge structures : final report.
DOT National Transportation Integrated Search
2011-05-01
The objectives of this research were to evaluate the feasibility and performance of self-consolidating concrete (SCC) made with local aggregates for use in cast-in-place and precast concrete applications and to develop draft specifications, acceptanc...
Fly ash in concrete : final report.
DOT National Transportation Integrated Search
1990-08-01
This study was initiated to develop information regarding the use of fly ash in portland cement concrete for state construction projects. : Concrete mixes containing 10%, 20%, 30%, 40% and 60% fly ash were evaluated in the laboratory in combination w...
Coatings, sealants and filters to address bridge concrete deterioration and aesthetics : Phase I.
DOT National Transportation Integrated Search
2006-06-01
The study addresses experimental evaluation and testing of concrete coatings for maintenance purposes on structural (steel reinforced) concrete. The test methods employed are intended to identify coatings and sealers for eventual incorporation into a...
Design and evaluation of high-volume fly ash (HVFA) concrete mixes.
DOT National Transportation Integrated Search
2012-10-01
Concrete is the worlds most consumed man-made material. Unfortunately, the production of portland cement, the active ingredient in concrete, generates a significant amount of carbon dioxide. For each pound of cement produced, approximately one pou...
DOT National Transportation Integrated Search
2013-06-01
The proposed study involves investigating long carbon fiber reinforced concrete as a method of mitigating earthquake damage to : bridges and other infrastructure components. Long carbon fiber reinforced concrete has demonstrated significant resistanc...
Investigation of concrete containing slag : Hampton River Bridge.
DOT National Transportation Integrated Search
1986-01-01
The study evaluated the properties of concretes containing slag in a 50% replacement of the portland cement to assess their suitability as an alternative to the portland cement concretes normally used in the construction of bridge substructures. For ...
Design and evaluation of high-volume fly ash (HVFA) concrete mixes.
DOT National Transportation Integrated Search
2012-10-01
Concrete is the worlds most consumed man-made material. Unfortunately, the production of portland cement, the active : ingredient in concrete, generates a significant amount of carbon dioxide. For each pound of cement produced, approximately one :...
DOT National Transportation Integrated Search
2006-01-01
This study evaluated two half-cell mapping methods for nondestructive evaluation of epoxy-coated rebar (ECR) in concrete: the semi-fixed bi-electrode and the moving bi-electrode methods. These methods were expected to provide early detection of corro...
Evaluation of fiber reinforced concrete : final report.
DOT National Transportation Integrated Search
1991-05-01
This study was conducted to evaluate the physical properties of plastic and hardened fiber reinforced concrete using three basic types of fibers: steel, fiberglass and polypropylene. Fibers have been shown to increase flexural and tensile strength, d...
Premixed polymer concrete overlays.
DOT National Transportation Integrated Search
1990-01-01
The results of a study undertaken to evaluate premixed polymer concrete overlays (PMPCO) over a 3-year period are presented. The PMPCO evaluated were constructed with polyester amide para resin and silica sand 1;. polyester styrene resin 1 and silica...
Evaluation of performance based concrete for bridge decks.
DOT National Transportation Integrated Search
2015-06-01
The Washington State Department of Transportation (WSDOT) revised the concrete : specification for bridge decks in 2011 to be more performance based with the desired effect of : having less early-age shrinkage cracking. This report evaluates a sample...
Evaluation of static resistance of deep foundations.
DOT National Transportation Integrated Search
2017-05-01
The focus of this research was to evaluate and improve Florida Department of Transportation (FDOT) FB-Deep software prediction of nominal resistance of H-piles, prestressed concrete piles in limestone, large diameter (> 36) open steel and concrete...
Evaluation of concrete pavements with materials-related distress : appendix G.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavement patching techniques.
DOT National Transportation Integrated Search
1989-01-01
This final report presents the results of a study undertaken to improve in concrete pavement patching techniques. Activities included an evaluation of the suitability of the impact hammer and maturity calculations for determining when a patch is read...
Evaluation of concrete pavements with materials-related distress : final report.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors : contributing to pavement distress observed in the field were determined, including expansive : alkali-silica reactivity and freeze-thaw deterioration related to poor ...
Evaluation of concrete pavements with materials-related distress : appendix F.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavements with materials-related distress : appendix E.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavements with materials-related distress : appendix D.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavements with materials-related distress : appendix B.
DOT National Transportation Integrated Search
2010-02-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of new asphalt concrete density specification.
DOT National Transportation Integrated Search
1988-01-01
The purpose of this investigation was to evaluate a new asphalt concrete density specification that utilizes a nuclear gauge and a control strip technique. The specification was studied on two field projects, and recommendations were made to improve ...
Evaluation of continuously reinforced concrete pavement : final report.
DOT National Transportation Integrated Search
1975-02-01
This report provides a review of the performance and structural characteristic exhibited on five continuously reinforced concrete pavement projects in the State of Louisiana. The performance characteristics were evaluated by means of the Mays Ride Me...
Evaluation of concrete pavements with materials-related distress : appendix C.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Sherzer, Gili; Gao, Peng; Schlangen, Erik; Ye, Guang; Gal, Erez
2017-02-28
Modeling the complex behavior of concrete for a specific mixture is a challenging task, as it requires bridging the cement scale and the concrete scale. We describe a multiscale analysis procedure for the modeling of concrete structures, in which material properties at the macro scale are evaluated based on lower scales. Concrete may be viewed over a range of scale sizes, from the atomic scale (10 -10 m), which is characterized by the behavior of crystalline particles of hydrated Portland cement, to the macroscopic scale (10 m). The proposed multiscale framework is based on several models, including chemical analysis at the cement paste scale, a mechanical lattice model at the cement and mortar scales, geometrical aggregate distribution models at the mortar scale, and the Lattice Discrete Particle Model (LDPM) at the concrete scale. The analysis procedure starts from a known chemical and mechanical set of parameters of the cement paste, which are then used to evaluate the mechanical properties of the LDPM concrete parameters for the fracture, shear, and elastic responses of the concrete. Although a macroscopic validation study of this procedure is presented, future research should include a comparison to additional experiments in each scale.
Sherzer, Gili; Gao, Peng; Schlangen, Erik; Ye, Guang; Gal, Erez
2017-01-01
Modeling the complex behavior of concrete for a specific mixture is a challenging task, as it requires bridging the cement scale and the concrete scale. We describe a multiscale analysis procedure for the modeling of concrete structures, in which material properties at the macro scale are evaluated based on lower scales. Concrete may be viewed over a range of scale sizes, from the atomic scale (10−10 m), which is characterized by the behavior of crystalline particles of hydrated Portland cement, to the macroscopic scale (10 m). The proposed multiscale framework is based on several models, including chemical analysis at the cement paste scale, a mechanical lattice model at the cement and mortar scales, geometrical aggregate distribution models at the mortar scale, and the Lattice Discrete Particle Model (LDPM) at the concrete scale. The analysis procedure starts from a known chemical and mechanical set of parameters of the cement paste, which are then used to evaluate the mechanical properties of the LDPM concrete parameters for the fracture, shear, and elastic responses of the concrete. Although a macroscopic validation study of this procedure is presented, future research should include a comparison to additional experiments in each scale. PMID:28772605
Leung Tang, Pik; Alqassim, Mohammad; Nic Daéid, Niamh; Berlouis, Leonard; Seelenbinder, John
2016-05-01
Concrete is by far the world's most common construction material. Modern concrete is a mixture of industrial pozzolanic cement formulations and aggregate fillers. The former acts as the glue or binder in the final inorganic composite; however, when exposed to a fire the degree of concrete damage is often difficult to evaluate nondestructively. Fourier transform infrared (FT-IR) spectroscopy through techniques such as transmission, attenuated total reflectance, and diffuse reflectance have been rarely used to evaluate thermally damaged concrete. In this paper, we report on a study assessing the thermal damage of concrete via the use of a nondestructive handheld FT-IR with a diffuse reflectance sample interface. In situ measurements can be made on actual damaged areas, without the need for sample preparation. Separate multivariate models were developed to determine the equivalent maximal temperature endured for three common industrial concrete formulations. The concrete mixtures were successfully modeled displaying high predictive power as well as good specificity. This has potential uses in forensic investigation and remediation services particularly for fires in buildings. © The Author(s) 2016.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nixon, R.
The deterioration of concrete structures due to chloride induced reinforcing steel corrosion such as in elevated concrete floor slabs, columns, and beams in bleach plants is a constant and growing problem within the pulp and paper industry. In general, the condition analysis methods used for assessing the extent of bleach plant concrete degradation include physical testing of drilled concrete core samples, chloride ion concentration testing, half-cell potential measurements, and physical sounding of concrete surfaces, i.e. chain drag for topside surfaces and hammer sounding of soffit surfaces. While this paper does not promote any vastly different evaluative methods, it does sharemore » learnings relative to interpreting the data provided by these typical test methods. It further offers some recommendations on how to improve the use of these typical evaluation techniques and offers some other test methods which should be considered as valuable additions for such evaluations. One of the most common methods which has been used in the past for large scale bleach plant concrete restoration has been the application of site dry mixed shotcrete for rebuilding the soffits of floor slabs and the faces of columns and beams. More often than not, bulk mixed dry shotcrete repairs have not been cost-effective because they prematurely failed due to excessive hydration related shrinkage cracking, lack of sufficient adhesion to the parent concrete substrate or other problems related to poor durability or construction practice.« less
Understanding and mitigating effects of chloride deicer exposure on concrete.
DOT National Transportation Integrated Search
2014-09-01
Field and laboratory investigations were conducted to examine the effects of chloride deicers on concrete : bridge decks and to identify and evaluate best practices and products to mitigate such effects. The concrete bridge decks : exposed to KAc or ...
DOT National Transportation Integrated Search
2015-09-01
Kentucky's bridges continue to age and experience distress. The intrusion of chlorides into : concrete remains the primary mechanism for deterioration. It leads to reinforcing steel corrosion : that damages the adjoining concrete structure. This stud...
Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavements.
DOT National Transportation Integrated Search
2013-11-01
This research effort was focused on evaluating the feasibility of using minimally processed reclaimed : asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated : that concretes with up to 50 percent of the fi...
Investigation of optimized graded concrete for Oklahoma.
DOT National Transportation Integrated Search
2013-07-01
This report presents the results of several novel test methods to investigate concrete for slip formed paving. These tests include the Box Test, a novel test to evaluate the response of concrete to vibration, the AIMS2, an automated test for aggregat...
Evaluate the use of reclaimed concrete aggregate in french drain applications.
DOT National Transportation Integrated Search
2014-02-01
Recycled concrete aggregate (RCA) is often used as a replacement of virgin aggregate in road : foundations (base course), embankments, hot-mix asphalt, and Portland cement concrete; however, the : use of RCA in exfiltration drainage systems, such as ...
Recycled concrete aggregate : field implementation at the Stan Musial Veterans Memorial Bridge.
DOT National Transportation Integrated Search
2014-08-01
The main objective of this research is to evaluate the feasibility of using RCA for concrete production in rigid pavement applications. : The experimental program was undertaken to investigate the performance of different concrete made with different...
Evaluate the use of reclaimed concrete aggregate in french drain applications : [summary].
DOT National Transportation Integrated Search
2014-02-01
Recycled concrete aggregate (RCA) is often used : as a replacement of virgin aggregate in road : foundations (base course), embankments, hot-mix : asphalt, and Portland cement concrete. However, : the use of RCA in exfiltration drainage systems, : su...
Alkali silica reaction (ASR) in cement free alkali activated sustainable concrete.
DOT National Transportation Integrated Search
2016-12-19
This report summarizes the findings of an experimental evaluation into alkali silica : reaction (ASR) in cement free alkali-activated slag and fly ash binder concrete. The : susceptibility of alkali-activated fly ash and slag concrete binders to dele...
Use of reclaimed asphalt pavement in concrete pavement slabs.
DOT National Transportation Integrated Search
2012-10-01
This study evaluated the feasibiltiy of using RAP as aggregate replacement in concrete for use in pavement. Four different RAPs from FDOT approved RAP sources were used. Concrete mixtures with 0%, 20%, 40%, 70%, and 100% aggregate replacement by RAP ...
Economics of Concrete and Wood Tie Track Structures
DOT National Transportation Integrated Search
1978-08-01
This report presents results from an evaluation of the economic benefits of concrete- versus wood-tie track. The analysis includes the life-cycle capital, maintenance, and renewal costs for concrete- and wood-tie track for four specific test cases an...
Statistical methods for the quality control of steam cured concrete : final report.
DOT National Transportation Integrated Search
1971-01-01
Concrete strength test results from three prestressing plants utilizing steam curing were evaluated statistically in terms of the concrete as received and the effectiveness of the plants' steaming procedures. Control charts were prepared to show tren...
1988-11-01
TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP Breakwater REMR (Repair, Evaluation, Concrete armor units...Maintenance, and Rehabilitation) Jetty Rubble-mound structures 19. ABSTRACT (Continue on reverse if necessary and identify by block number) :-This...have been repaired since construction. Other construction materials that have been used include steel, dolosse, concrete cap, concrete block , and
2013-01-08
This re- search ignores effects on long-term durability, trafficability, temperature rebar corrosion , and other concerns that are of minimal... concrete because it can cause corrosion of steel reinforcement. However, the corrosion problem develops slowly with time; therefore, this problem has a...ER D C/ CR RE L TR -1 3- 1 Laboratory Evaluation of Expedient Low- Temperature Concrete Admixtures for Repairing Blast Holes in Cold
NASA Astrophysics Data System (ADS)
Daukšys, M.; Klovas, A.; Venčkauskas, L.
2017-09-01
This study mainly lays emphasis on examining the influence of concrete mixture rheological properties on the quality of formed concrete surfaces. Mixture’s fine aggregate change was taken into the consideration. Over the course of concrete mixture preparation the inner ratio of fine aggregate (sand: fraction of 0/1 and 0/4) was changed. The idea was to increase the quantity of fine particles in the total aggregate’s volume therefore quantity of sand (fraction 0/1) was increased. Six different concrete mixture’s compositions were designed as well as three specimens (concrete piles of 1m2 surface area) were casted. Rheological properties of concrete mixtures were analytically obtained and the quality of formed concrete surfaces was evaluated using image analysis method “BetonGUY 2.0”. As can be obtained from the dependence between concrete mixture rheological properties and its formed surface quality, the increase of concrete mixture’s yield stress and plastic viscosity reduces the quantity of air pores on formed concrete surfaces.
Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures
NASA Technical Reports Server (NTRS)
Jones, Justin S.; Polis, Daniel L.; Rowles, Russell R.; Segal, Kenneth N.
2011-01-01
The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to segmented barrel structures needed for autoclave cured barrel segments due to autoclave size constraints. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (Z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the Z-fiber weave to a fully interlocked weave with comparable fiber bias, the Z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.
Chai, Hwa Kian; Liu, Kit Fook; Behnia, Arash; Yoshikazu, Kobayashi; Shiotani, Tomoki
2016-04-16
Concrete is the most ubiquitous construction material. Apart from the fresh and early age properties of concrete material, its condition during the structure life span affects the overall structural performance. Therefore, development of techniques such as non-destructive testing which enable the investigation of the material condition, are in great demand. Tomography technique has become an increasingly popular non-destructive evaluation technique for civil engineers to assess the condition of concrete structures. In the present study, this technique is investigated by developing reconstruction procedures utilizing different parameters of elastic waves, namely the travel time, wave amplitude, wave frequency, and Q-value. In the development of algorithms, a ray tracing feature was adopted to take into account the actual non-linear propagation of elastic waves in concrete containing defects. Numerical simulation accompanied by experimental verifications of wave motion were conducted to obtain wave propagation profiles in concrete containing honeycomb as a defect and in assessing the tendon duct filling of pre-stressed concrete (PC) elements. The detection of defects by the developed tomography reconstruction procedures was evaluated and discussed.
Alternative carbohydrate reserves used in the daily cycle of crassulacean acid metabolism
C.C. Black; J.-Q. Chen; R.L. Doong; M.N. Angelov; Shi-Jean S. Sung
1996-01-01
Each day a massive interlocked biochemical cycle occurs in the green tissues of crassulacean acid metabolism plants.The function of this interlocked cycle, in its simplest context, is to furnish most of the CO2 for CAM plant photosynthesis.In this unified presentation our aims are (1) to divide CAM plants into two metabolic groups, (2) to...
Modelling the evolution of a bi-partite network Peer referral in interlocking directorates*
Edling, Christofer
2010-01-01
A central part of relational ties between social actors are constituted by shared affiliations and events. The action of joint participation reinforces personal ties between social actors as well as mutually shared values and norms that in turn perpetuate the patterns of social action that define groups. Therefore the study of bipartite networks is central to social science. Furthermore, the dynamics of these processes suggests that bipartite networks should not be considered static structures but rather be studied over time. In order to model the evolution of bipartite networks empirically we introduce a class of models and a Bayesian inference scheme that extends previous stochastic actor-oriented models for unimodal graphs. Contemporary research on interlocking directorates provides an area of research in which it seems reasonable to apply the model. Specifically, we address the question of how tie formation, i.e. director recruitment, contributes to the structural properties of the interlocking directorate network. For boards of directors on the Stockholm stock exchange we propose that a prolific mechanism in tie formation is that of peer referral. The results indicate that such a mechanism is present, generating multiple interlocks between boards. PMID:24944435
Freeze-thaw durability of concrete: Ice formation process in pores
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cai, H.; Liu, X.
1998-09-01
Freeze-thaw durability of concrete is of great importance to hydraulic structures in cold areas. Study of ice formation process in concrete pores is necessary to evaluate the damages in concrete caused by freezing. In this paper, freezing of pore solution in concrete exposed to a freeze-thaw cycle is studied by following the change of concrete electrical conductivity with freezing temperatures. Concretes were subjected to freeze-thaw cycles with temperature varying between {minus}0 C and {minus}20 C. In the freezing process, the changing rate of concrete electrical conductivity obviously decreases at about {minus}10 C, indicating that more pore solution in concrete freezesmore » above {minus}10 C than below {minus}10C. According to Powers` static hydraulic pressure hypothesis, it is thought that frost damage mainly occurs between 0 C and {minus}100 C. To ordinary concrete, frost damages below {minus}10 C are negligible.« less
Evaluation of a concrete pavement restoration project in Virginia.
DOT National Transportation Integrated Search
1994-01-01
The purpose of this Federal Highway Administration Demonstration Project was to evaluate the installation and performance of a section of I-81 in Botetourt County, Virginia, that was rehabilitated by concrete pavement restoration (CPR) methods. The s...
DOT National Transportation Integrated Search
2017-08-01
In continuation of a previously completed project entitled Evaluate Presawn Transverse Thermal Cracks for Asphalt Concrete Pavement, this project was a further effort to understand important variables in the thermal cracking process through continued...
Evaluation of synthetic fabrics for the reduction of reflective cracking : final report.
DOT National Transportation Integrated Search
1975-04-01
This research was undertaken to evaluate the effectiveness of two synthetic fabrics in relieving stress and reducing or eliminating reflection cracking in the asphaltic concrete overlay of existing distressed concrete pavements. : The polypropylene f...
Evaluation of narrow transverse contraction joints in jointed plain concrete pavements.
DOT National Transportation Integrated Search
2006-03-01
This report presents the results of a research project conducted at the Louisiana Transportation Research Center (LTRC) to evaluate the performance of narrow transverse contraction joints to control cracking in jointed plain concrete pavements. In ad...
Bottom ash as aggregate replacement in concrete.
DOT National Transportation Integrated Search
2013-06-01
The objective of the proposed study is to evaluate bottom ash as a partial or total replacement of the fine and coarse aggregate in : concrete. This program will characterize and evaluate available bottom ash sources as potential replacement of both ...
Evaluation of microcracking and chemical deterioration in concrete pavements.
DOT National Transportation Integrated Search
1995-10-31
The major objective of this research project was to investigate the : chemistry and morphology of portland cement concrete pavements in : Iowa. The integrity of the various pavements was evaluated qualitatively, : based on the presence or absence of ...
Evaluation of concrete pavements with materials-related distress : appendix A, part 1.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavements with materials-related distress : appendix A, part 3.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of concrete pavements with materials-related distress : appendix A, part 2.
DOT National Transportation Integrated Search
2010-03-02
An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...
Evaluation of full depth asphaltic concrete pavements : final report.
DOT National Transportation Integrated Search
1982-10-01
the aim of this study was to evaluate the full depth asphaltic concrete pavement design concept by observing the performance characteristics of two 13-inch pavements constructed in 1970. Pavement performance measurements, over an 11-year period, incl...
DOT National Transportation Integrated Search
1995-07-01
The objectives of this work were to examine placement strategies for reference electrodes and to evaluate the suitability of graphite reference electrodes as imbedded reference electrodes in reinforced concrete structures that are cathodically protec...
Evaluation of the in-service safety performance of safety-shape and vertical concrete barriers.
DOT National Transportation Integrated Search
2011-12-16
Roadside concrete barriers have been widely used to protect errant motorists from hitting : roadside hazards or obstacles. Two concrete barrier profiles, vertical and safety-shape, have been used : for this purpose. The safety-shape profile has been ...
Evaluate the Use of Mineral Admixtures in Concrete to Mitigate Alkali-Silica Reactivity.
DOT National Transportation Integrated Search
1996-12-01
The increased use of mineral admixtures in portland cement concrete demands a better understanding of their properties and effects on hardened concrete. One of several beneficial advantages of mineral admixtures like flyash and silica fume is their p...
High-performance continuously reinforced concrete pavements in Richmond and Lynchburg, Virginia.
DOT National Transportation Integrated Search
2007-01-01
This study evaluated the properties of two high performance concrete (HPC) paving projects in Virginia. These continuously reinforced concrete pavements were placed on State Route 288 near Richmond and on the U.S. 29 Madison Heights Bypass in Lynchbu...
DOT National Transportation Integrated Search
2012-09-01
Properties of concrete embodying materials typically used in Wisconsin paving projects were evaluated in support of future : implementation of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG). The primary concrete : properties studied w...
DOT National Transportation Integrated Search
2012-09-01
Properties of concrete embodying materials typically used in Wisconsin paving projects were evaluated in support of future : implementation of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG). The primary concrete : properties studied w...
Evaluation of Portland cement concrete with internal curing capabilities : tech summary.
DOT National Transportation Integrated Search
2016-09-01
Proper curing is the key to durable and sustainable concrete structures. When a concrete mixture is : designed, delivered, poured, and consolidated, curing is the last and the most critical part for a quality final : product. Insufficient curing of c...
DOT National Transportation Integrated Search
2014-09-01
Corrosion of steel-reinforced concrete bridges is a serious problem facing the WVDOT. This : paper provides an overview of techniques for evaluating the condition of reinforced concrete : bridge elements; methods for modeling the remaining service li...
Evaluation of mix designs and test procedures for pervious concrete.
DOT National Transportation Integrated Search
2014-10-01
Pervious concrete is mixture of cement, aggregate, and water that provide a level of porosity which allows : water to percolate into the sub-grade. It differs from the conventional concrete since it usually contains a : smaller amount of fine aggrega...
Evaluation of CDOT specifications for class H and HT crack resistant concrete.
DOT National Transportation Integrated Search
2010-06-01
This study examined the performance of concrete mixtures designed to increase cracking resistance for Colorado bridge decks. The : current CDOT Class H and HT concrete mixtures and nine other mixtures were investigated to aid in the development of a ...
Evaluation of sprayed-on metalizing for precast prestressed concrete I-beams
DOT National Transportation Integrated Search
2002-04-01
Cathodic protection has been used as an effective means of arresting corrosion in reinforced concrete. A galvanic system typically consists of a sacrificial anode, some form of adhesive or fastening system to secure the anode to the concrete, and an ...
Garcia, Anthony R.; Johnston, Roger G.
2003-07-08
The present invention provides an apparatus and method whereby the reliability and tamper-resistance of tamper indicators can be improved. A flexible connector may be routed through a latch for an enclosure such as a door or container, and the free ends of the flexible connector may be passed through a first locking member and firmly attached to an insert through the use of one or more attachment members such as set screws. A second locking member may then be assembled in interlocking relation with the first locking member to form an interlocked assembly around the insert. The insert may have one or more sharp projections extending toward the first or second locking member so that any compressive force applied in an attempt to disassemble the interlocked assembly results in permanent, visible damage to the first or second locking member.
Thermal static bending of deployable interlocked booms
NASA Technical Reports Server (NTRS)
Staugaitis, C. L.; Predmore, R. E.
1973-01-01
Metal ribbons processed with a heat-forming treatment are enabled to form tubelike structures when deployed from a roll. Deployable booms of this have been utilized for gravity-gradient stabilization on the RAE, ATS, and Nimbus D satellites. An experimental thermal-mechanics test apparatus was developed to measure the thermal static bending and twist of booms up to 3 meters long. The apparatus was calibrated by using the correlation between calculated and observed thermal bending of a seamless tube. Thermal static bending values of 16 interlocked deployable booms were observed to be within a factor of 2.5 of the values calculated from seamless-tube theory. Out-of-Sun-plane thermal bending was caused by complex heat transfer across the interlocked seam. Significant thermal static twisting was not observed.
Simplified equation for Young's modulus of CNT reinforced concrete
NASA Astrophysics Data System (ADS)
Chandran, RameshBabu; Gifty Honeyta A, Maria
2017-12-01
This research investigation focuses on finite element modeling of carbon nanotube (CNT) reinforced concrete matrix for three grades of concrete namely M40, M60 and M120. Representative volume element (RVE) was adopted and one-eighth model depicting the CNT reinforced concrete matrix was simulated using FEA software ANSYS17.2. Adopting random orientation of CNTs, with nine fibre volume fractions from 0.1% to 0.9%, finite element modeling simulations replicated exactly the CNT reinforced concrete matrix. Upon evaluations of the model, the longitudinal and transverse Young's modulus of elasticity of the CNT reinforced concrete was arrived. The graphical plots between various fibre volume fractions and the concrete grade revealed simplified equation for estimating the young's modulus. It also exploited the fact that the concrete grade does not have significant impact in CNT reinforced concrete matrix.
Sustainability and durability analysis of reinforced concrete structures
NASA Astrophysics Data System (ADS)
Horáková, A.; Broukalová, I.; Kohoutková, A.; Vašková, J.
2017-09-01
The article describes an assessment of reinforced concrete structures in terms of durability and sustainable development. There is a short summary of findings from the literature on evaluation methods for environmental impacts and also about corrosive influences acting on the reinforced concrete structure, about factors influencing the durability of these structures and mathematical models describing the corrosion impacts. Variant design of reinforced concrete structure and assessment of these variants in terms of durability and sustainability was performed. The analysed structure was a concrete ceiling structure of a parking house for cars. The variants differ in strength class of concrete and thickness of concrete slab. It was found that in terms of durability and sustainable development it is significantly preferable to use higher class of concrete. There are significant differences in results of concrete structures durability for different mathematical models of corrosive influences.
Development of acoustic emission evaluation method for repaired prestressed concrete bridge girders.
DOT National Transportation Integrated Search
2011-06-01
Acoustic emission (AE) monitoring has proven to be a useful nondestructive testing tool in ordinary reinforced concrete beams. Over the past decade, however, the technique has also been used to test other concrete structures. It has been seen that ac...
Evaluation of concrete inlay for continuously reinforced concrete pavement rehabilitation.
DOT National Transportation Integrated Search
2010-06-01
In 1996, WisDOT constructed a concrete inlay test section on I43 in Manitowoc County. The existing pavement was CRCP constructed in 1978 and was badly deteriorated with punchouts. In the area of the 2777foot test section, the existing paveme...
CRASH TEST AND EVALUATION OF RESTRAINED SAFETY-SHAPE CONCRETE BARRIERS ON CONCRETE BRIDGE DECK
DOT National Transportation Integrated Search
2018-01-01
This research designed and tested a new portable concrete barrier that meets the performance of MASH TL-4 and can be used in temporary and permanent applications on bridge decks. Additionally, this new barrier system will minimize deflection, allowin...
Flyash in continuous reinforced PCC pavement and lean concrete base : interim report.
DOT National Transportation Integrated Search
1986-08-01
The objectives of this test section were: 1) To test and evaluate the physical characteristics of flyash concrete in comparison to non-flyash concrete. Tests will be conducted to see if flyash strength, and if the current specifications for flyash ca...
An evaluation of new inhibitors for rebar corrosion in concrete.
DOT National Transportation Integrated Search
2003-01-01
The corrosion of reinforcing steel in concrete is estimated to affect more than 50% of the 575,000 bridges in the United States. One approach to mitigating this problem is to use corrosion-inhibitive compounds admixed into the concrete paste. This st...
Evaluation of a highway bridge constructed using high strength lightweight concrete bridge girders.
DOT National Transportation Integrated Search
2011-04-01
The use of high performance concretes to provide longer bridge spans has been limited due to the capacity of existing infrastructure to handle the load of the girders during transportation. The use of High Strength Lightweight Concrete (HSLW) can pro...
DOT National Transportation Integrated Search
2015-03-01
Due to the low workability of slipform concrete mixtures, the science of rheology is not strictly applicable for such concrete. However, : the concept of rheological behavior may still be considered useful. A novel workability test method (Vibrating ...
Evaluation of Portland Cement Concrete with Internal Curing Capabilities : Research Project Capsule
DOT National Transportation Integrated Search
2012-09-01
Proper curing is the key to durable and sustainable concrete structures. When a concrete mixture : is designed, delivered, poured, and consolidated, curing is the last and the most critical part for : a fi nal product of great quality. Insuffi cient ...
Effect of calcium nitrite on the properties of concrete used in prestressed piles and beams.
DOT National Transportation Integrated Search
1992-01-01
This study evaluates the concretes in steam-cured prestressed piles and beams containing calcium nitrite as protection against chloride-induced corrosion of the steel strands and assesses their field performance over a 3-year period. Concretes contai...
DOT National Transportation Integrated Search
2015-10-01
This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as : aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent : o...
Assessing a Reclaimed Concrete Up-Cycling Scheme through Life-Cycle Analysis
NASA Astrophysics Data System (ADS)
Guignot, Sylvain; Bru, Kathy; Touzé, Solène; Ménard, Yannick
The present study evaluates the environmental impacts of a recycling scheme for gravels from building concretes wastes, in which the liberated aggregates are reused in structural concretes while the residual mortar fines are sent to the raw mill of a clinker kiln.
Evaluation of portland cement concrete pavement with high slag content cement.
DOT National Transportation Integrated Search
2013-10-01
The performance of a section of concrete pavement built with 30 percent Ground Granulated Blast Furnace Slag (GGBFS) is compared to a control section of concrete pavement built with 25 percent GGBFS to determine if the higher slag content pavement is...
DOT National Transportation Integrated Search
2016-10-01
Water permeability of concrete is one of the key factors concerning : many concrete deterioration problems. It is often evaluated indirectly by : measuring the volume of permeable voids through the KT-73 (2012) testing : procedures. These procedures ...
Evaluation of hydraulic cement concrete overlays placed on three pavements in Virginia.
DOT National Transportation Integrated Search
2000-08-01
Three hydraulic cement concrete pavement overlays were placed in the summer of 1995 at three locations in Virginia. Two of the overlays were placed on continuously reinforced concrete pavement to prevent spalling caused by a shy cover over the reinfo...
Evaluation of treatment options for ASR-affected concrete : final report, December 11, 2009.
DOT National Transportation Integrated Search
2009-12-11
This research project was undertaken to evaluate the potential of using surface treatments including lithium nitrate, : sodium tartarate, siloxanes, silane, and boiled linseed oil to mitigate or slow the rate of concrete deterioration : associated wi...
Performance evaluation of corrosion inhibitors and galvanized steel in concrete exposure specimens.
DOT National Transportation Integrated Search
1999-01-01
Corrosion inhibitor admixtures (CIA) and galvanized reinforcing steel (GS) are used for the corrosion protection for reinforced concrete bridges. The results of a 3.5-year evaluation of exposure specimens containing CIA from three different manufactu...
Evaluation of bent caps in reinforced concrete deck girder bridges : part 2.
DOT National Transportation Integrated Search
2008-09-01
This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...
Evaluation of bent caps in reinforced concrete deck girder bridges : part 1.
DOT National Transportation Integrated Search
2008-09-01
This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...
Durability of saw-cut joints in plain cement concrete pavements.
DOT National Transportation Integrated Search
2011-01-01
The objective of this project was to evaluate factors influencing the durability of the joints in portland cement concrete : pavement in the state of Indiana. Specifically this work evaluated the absorption of water, the absorption of deicing solutio...
Evaluation of hydraulic cement concretes containing slag added at the mixer.
DOT National Transportation Integrated Search
1985-01-01
The study evaluated the effect of ground, granulated, iron slags on the properties of hydraulic cement concretes such as normally used in highway construction. Two cements with different alkali contents and two slags with different activity indices, ...
Technology evaluation of characterization of the air void system in concrete.
DOT National Transportation Integrated Search
2009-09-01
The objective of this project was to evaluate current technologies that have the capability of characterizing the air void system in concrete within the first several hours of placement. This objective was met by developing a comprehensive technology...
Technology evaluation on characterization of the air void system in concrete.
DOT National Transportation Integrated Search
2009-09-17
The objective of this project was to evaluate current technologies that have the capability of characterizing the air void system in concrete within the first several hours of placement. This objective was met by developing a comprehensive technology...
Evaluation of microsilica admixture for production of high strength concrete.
DOT National Transportation Integrated Search
1990-08-01
This study consisted of a laboratory evaluation of the effect of microsilica on the physical properties of both plastic and hardened portland cement concrete. Microsilica (silica fume) is a by-product of the industrial manufacture of ferro silicon an...
DOT National Transportation Integrated Search
2014-05-01
The overall objective of this research study is to evaluate the structural performance and loadcarrying : capacity of bonded concrete overlay pavement structures through accelerated pavement : testing and document the experience of mix design and con...
DOT National Transportation Integrated Search
2017-11-01
This report documents the evaluation of cement replacement with mekaolin and slag materials supplied by multiple vendors by measuring compressive strength, tensile strength, modulus of rupture, modulus of elasticity, sulfate expansion, alkali-silica ...
Evaluation of concrete cover by surface wave technique: Identification procedure
NASA Astrophysics Data System (ADS)
Piwakowski, Bogdan; Kaczmarek, Mariusz; Safinowski, Paweł
2012-05-01
Concrete cover degradation is induced by aggressive agents in ambiance, such as moisture, chemicals or temperature variations. Due to degradation usually a thin (a few millimeters thick) surface layer has porosity slightly higher than the deeper sound material. The non destructive evaluation of concrete cover is vital to monitor the integrity of concrete structures and prevent their irreversible damage. In this paper the methodology applied by the classical technique used for ground structure recovery called Multichanel Analysis of Surface Waves is discussed as the NDT tool in civil engineering domain to characterize the concrete cover. In order to obtain the velocity as a function of sample depth the dispersion of surface waves is used as an input for solving inverse problem. The paper describes the inversion procedure and provides the practical example of use of developed system.
ERIC Educational Resources Information Center
Slaughter, Sheila; Thomas, Scott L.; Johnson, David R.; Barringer, Sondra N.
2014-01-01
We examined the potential for institutional conflict of interest between the 26 private universities belonging to the Association of American Universities and the corporations to which they are tied through their boards of trustees. We were interested in the degree to which interlocks may have tightened over three points across an 11-year period…
Investigation of porous asphalt microstructure using optical and electron microscopy.
Poulikakos, L D; Partl, M N
2010-11-01
Direct observations of porous asphalt concrete samples in their natural state using optical and electron microscopy techniques led to useful information regarding the microstructure of two mixes and indicated a relationship between microstructure and in situ performance. This paper presents evidence that suboptimal microstructure can lead to premature failure thus making a first step in defining well or suboptimal performing pavements with a bottom-up approach (microstructure). Laboratory and field compaction produce different samples in terms of the microstructure. Laboratory compaction using the gyratory method has produced more microcracks in mineral aggregates after the binder had cooled. Well-performing mixes used polymer-modified binders, had a more homogeneous void structure with fewer elongated voids and better interlocking of the aggregates. Furthermore, well-performing mixes showed better distribution of the mastic and better coverage of the aggregates with bitumen. Low vacuum scanning electron microscopy showed that styrene butadiene styrene polymer modification in binder exists in the form of discontinuous globules and not continuous networks. A reduction in the polymer phase was observed as a result of aging and in-service use. © 2010 The Authors Journal compilation © 2010 The Royal Microscopical Society.
Detection of cracks on concrete surfaces by hyperspectral image processing
NASA Astrophysics Data System (ADS)
Santos, Bruno O.; Valença, Jonatas; Júlio, Eduardo
2017-06-01
All large infrastructures worldwide must have a suitable monitoring and maintenance plan, aiming to evaluate their behaviour and predict timely interventions. In the particular case of concrete infrastructures, the detection and characterization of crack patterns is a major indicator of their structural response. In this scope, methods based on image processing have been applied and presented. Usually, methods focus on image binarization followed by applications of mathematical morphology to identify cracks on concrete surface. In most cases, publications are focused on restricted areas of concrete surfaces and in a single crack. On-site, the methods and algorithms have to deal with several factors that interfere with the results, namely dirt and biological colonization. Thus, the automation of a procedure for on-site characterization of crack patterns is of great interest. This advance may result in an effective tool to support maintenance strategies and interventions planning. This paper presents a research based on the analysis and processing of hyper-spectral images for detection and classification of cracks on concrete structures. The objective of the study is to evaluate the applicability of several wavelengths of the electromagnetic spectrum for classification of cracks in concrete surfaces. An image survey considering highly discretized wavelengths between 425 nm and 950 nm was performed on concrete specimens, with bandwidths of 25 nm. The concrete specimens were produced with a crack pattern induced by applying a load with displacement control. The tests were conducted to simulate usual on-site drawbacks. In this context, the surface of the specimen was subjected to biological colonization (leaves and moss). To evaluate the results and enhance crack patterns a clustering method, namely k-means algorithm, is being applied. The research conducted allows to define the suitability of using clustering k-means algorithm combined with hyper-spectral images highly discretized for crack detection on concrete surfaces, considering cracking combined with the most usual concrete anomalies, namely biological colonization.
DOT National Transportation Integrated Search
2014-08-01
The evaluation of the curing process of a fresh concrete is critical to its construction process and monitoring. Traditionally stress : sensor and compressive wave sensor were often used to measure concrete properties. Bender element (BE) test, a non...
Evaluation of Canadian unconfined aggregate freeze-thaw tests for identifying nondurable aggregates.
DOT National Transportation Integrated Search
2012-06-01
Concrete is the most widely used material in construction. Aggregates contribute 60% to 75% of the total volume : of concrete. The aggregates play a key role in concrete durability. The U.S. Midwest has many aggregates that can : show distress in the...
Rapid test methods for the evaluation of concrete properties.
DOT National Transportation Integrated Search
1982-01-01
The objective of the project was to place a CERL/Kelly-Vail testing unit and a microwave oven in the field to perform tests of plastic concrete on construction projects. : The CERL/K-V tests were to determine water and cement content of the concrete ...
DOT National Transportation Integrated Search
2011-04-01
The use of high performance concretes to provide longer bridge spans has been limited due to the capacity of existing infrastructure to handle the load of the girders during transportation. The use of High Strength Lightweight Concrete (HSLW) can pro...
A field investigation of concrete overlays containing latex, silica fume, or Pyrament cement.
DOT National Transportation Integrated Search
1996-01-01
This study evaluated latex-modified concretes (LMC) and concretes containing silica fume (SFC) or Pyrament-blended cement (PBCC) in bridge deck overlays in the field. The condition of the overlays was monitored for 4 years. LMC and SFC were placed in...
DOT National Transportation Integrated Search
1982-01-01
A study of the installation and three-year performance evaluation of a fabric-reinforced bituminous concrete overlay of a jointed concrete pavement is reported. The fabric, a polypropylene in an asphaltic mastic, was shown to act as a significant det...
DOT National Transportation Integrated Search
2016-10-01
Water permeability of concrete is one of the key factors concerning many concrete deterioration : problems. It is often evaluated indirectly by measuring the volume of permeable voids through the KT-73 : (2012) testing procedures. These procedures in...
1989-04-01
corrosion of rebar Spalling of concrete surface IIl Detect hidden and beginning Location of rebar damage Beginning corrosion of rebar ...honeycombs MD Moderate defects: spalling of concrete minor corrosion of exposed rebar rust stains along rebar with or without visible cracking softening of...velocity. . Replenishment of the attacking chemical hgents. h. Higher temperatures. i. Corrosion of reinforcing steel. 46. Note that concrete which
Evaluation of corrosion inhibitors for concrete bridge deck patches and overlays.
DOT National Transportation Integrated Search
2003-01-01
This report presents the results to date of a national pooled fund study initiated in August 1996 to evaluate the long-term performance of bridges and outdoor exposure slabs damaged by chloride-induced corrosion that have concrete containing corrosio...
Laboratory Evaluation of Concrete Ties and Fastenings for Transit Use
DOT National Transportation Integrated Search
1979-03-01
This report was prepared as part of an ongoing research effort by the Urban Mass Transportation Administration (UMTA) to develop standard concrete ties for rapid transit use. The overall objective of this contract was to fabricate and evaluate, by la...
DOT National Transportation Integrated Search
1966-12-01
The primary objective of this study was to evaluate the gyratory kneading compactor and to investigate the possibilities and capabilities of this type of equipment. : Curves were developed for six different asphaltic concrete mixes with varying compa...
Evaluation of bent caps in reinforced concrete deck girder bridges, part 2 : final report.
DOT National Transportation Integrated Search
2008-09-01
This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...
Evaluation of bent caps in reinforced concrete deck girder bridges, part 1 : final report.
DOT National Transportation Integrated Search
2008-09-01
This report describes research conducted to enable evaluation of existing vintage bent cap beams in reinforced concrete : deck girder bridges. The report is organized into two parts: 1) flexural anchorage capacity response and prediction of : reduced...
Evaluation of ground granulated iron blast-furnace slag : grade-100.
DOT National Transportation Integrated Search
2002-09-01
Currently, the use of grade-120 Granulated Ground Blast Furnace Slag (GGBFS) is incorporated into the specifications of LA DOTD concrete mixes. This study evaluates grade-100 GGBFS and its effect on the properties of hydraulic cement concretes used i...
Evaluation of a highway bridge constructed using high strength lightweight concrete bridge girders.
DOT National Transportation Integrated Search
2011-04-01
The purpose of this research was to characterize the performance of High Strength Lightweight Concrete (HSLW) in precast, prestressed bridge girders and to evaluate their performance in a highway bridge. The mechanical properties and long-term time-d...
Nondestructive evaluation of the complex modulus master curve of asphalt concrete specimens
NASA Astrophysics Data System (ADS)
Gudmarsson, A.; Ryden, N.; Birgisson, B.
2013-01-01
The dynamic Young's modulus of asphalt concrete is directly related to pavement quality and is used in thickness design of pavements. There is a need for a nondestructive laboratory method to evaluate the complex modulus, which can be linked to nondestructive field measurements. This study applies seismic measurements to an asphalt concrete beam where resonant acoustic spectroscopy and optimization of frequency response functions are used to estimate the complex moduli. A good estimation of the master curve is obtained.
Evaluation of super-water reducers for highway applications
NASA Astrophysics Data System (ADS)
Whiting, D.
1981-03-01
Super-water reducers were characterized and evaluated as potential candidates for production of low water to cement ratio, high strength concretes for highway construction applications. Admixtures were composed of either naphthalene or melamine sulfonated formaldehyde condensates. A mini-slump procedure was used to assess dosage requirements and behavior of workability with time of cement pastes. Required dosage was found to be a function of tricalcium aluminate content, alkali content, and fineness of the cement. Concretes exhibited high rates of slump loss when super-water reducers were used. The most promising area of application of these products appears to be in production of dense, high cement content concrete using mobile concrete mixer/transporters.
Experimental and numerical analysis of interlocking rib formation at sheet metal blanking
NASA Astrophysics Data System (ADS)
Bolka, Špela; Bratuš, Vitoslav; Starman, Bojan; Mole, Nikolaj
2018-05-01
Cores for electrical motors are typically produced by blanking of laminations and then stacking them together, with, for instance, interlocking ribs or welding. Strict geometrical tolerances, both on the lamination and on the stack, combined with complex part geometry and harder steel strip material, call for use of predictive methods to optimize the process before actual blanking to reduce the costs and speed up the process. One of the major influences on the final stack geometry is the quality of the interlocking ribs. A rib is formed in one step and joined with the rib of the preceding lamination in the next. The quality of the joint determines the firmness of the stack and also influences its. The geometrical and positional accuracy is thus crucial in rib formation process. In this study, a complex experimental and numerical analysis of interlocking rib formation has been performed. The aim of the analysis is to numerically predict the shape of the rib in order to perform a numerical simulation of the stack formation in the next step of the process. A detailed experimental research has been performed in order to characterize influential parameters on the rib formation and the geometry of the ribs itself, using classical and 3D laser microscopy. The formation of the interlocking rib is then simulated using Abaqus Explicit. The Hilll 48 constitutive material model is based on extensive and novel material characterization process, combining data from in-plane and out-of-plane material tests to perform a 3D analysis of both, rib formation and rib joining. The study shows good correlation between the experimental and numerical results.
DOT National Transportation Integrated Search
2016-04-01
Concrete pavement design is currently centered on steel reinforcement, whether that reinforcement be in the : form of dowel bars, as is the case in jointed plain concrete pavement (JPCP), or in the form of continuous rebar : reinforcement, continuous...
DOT National Transportation Integrated Search
1986-01-01
The multiple-layer polymer concrete overlay on the Big Swan Creek Bridge was soundly bonded to the base concrete and providing excellent protection against the infiltration of chloride ions after 2 years in service. Evaluations of this and PC overlay...
DOT National Transportation Integrated Search
2014-01-01
Construction of a new prestressed bridge with Self-Consolidating Concrete (SCC) provided the opportunity to further study the time-dependent properties of SCC mix and its long-term performance; considering the results and recommendations of previous ...
DOT National Transportation Integrated Search
2014-01-01
Construction of a new prestressed bridge with Self-Consolidating Concrete (SCC) : provided the opportunity to further study the time-dependent properties of SCC mix and : its long-term performance; considering the results and recommendations of previ...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-15
... Inspection Protocol for Reinforced Concrete Highway Barriers and Bridge Railings. Background: Highway... separations. Most bridge railings are made of reinforced concrete. Despite the important role that they play... Federal Highway Administration concerning Non- Destructive Evaluation of concrete bridge railings. One of...
DOT National Transportation Integrated Search
2006-05-01
This research study, sponsored by the Federal Highway Administration, summarizes the field performance of eight high-early-strength (HES) : concrete patches between 1994 and 1998. The patches were constructed under the Strategic Highway Research Prog...
DOT National Transportation Integrated Search
1965-01-01
In this study, critical mechanical properties of structural lightweight concrete were determined and utilized in the evaluation of a design of concrete pavements. Also presented are the critical mechanical properties resulting from unrestrained and r...
DOT National Transportation Integrated Search
1979-01-01
The objective of this study was to investigate the resistance of field concretes containing fly ash to damage from cycles of freezing and thawing as evidenced by scaling, based upon a reevaluation of a field project. In 1955 and 1956 an experimental ...
Evaluation of continuously reinforced hydraulic cement concrete pavement at Virginia's Smart Road.
DOT National Transportation Integrated Search
2004-01-01
A two-lane continuously reinforced concrete pavement was built in Blacksburg, Virginia, as a part of Virginia's Smart Road. One of the lanes is 12 ft wide, and the other is 14 ft wide. The additional 2 ft was part of the shoulder. Below the concrete ...
Konan, Sujith; Rayan, Faizal; Manketelow, Andrew R J; Haddad, Fares S
2011-12-01
Infected periprosthetic fractures around total hip arthroplasties are an extremely challenging problem. We describe our experience of managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants. The Cannulock (Orthodesign, Christchurch, United Kingdom) uncoated stem was used in 12 cases, and the Kent hip prosthesis (Biomet Merck, Bridgend, United Kingdom), in 5 cases. Satisfactory outcome was noted in all cases, and in 11 cases, revision to a definitive stem has been undertaken after successful control of infection and fracture union. The use of interlocking stems offers a relatively appealing solution for a complex problem and avoids the complications that would be associated with resection of the entire femur or the use of large quantities of bone cement. Copyright © 2011 Elsevier Inc. All rights reserved.
Turbine component casting core with high resolution region
Kamel, Ahmed; Merrill, Gary B.
2014-08-26
A hollow turbine engine component with complex internal features can include a first region and a second, high resolution region. The first region can be defined by a first ceramic core piece formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement that once subjected to an intermediate thermal heat treatment process thermally deform to form a three dimensional interlocking joint between the first and second core pieces by allowing thermal creep to irreversibly interlock the first and second core pieces together such that the joint becomes physically locked together providing joint stability through thermal processing.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong
As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (similar to 75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass similar to 21.4 kilograms per mole) to a mixturemore » of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.« less