Science.gov

Sample records for concrete runway materials

  1. Test of LOX compatibility for asphalt and concrete runway materials

    NASA Technical Reports Server (NTRS)

    Moyers, C. V.; Bryan, C. J.; Lockhart, B. J.

    1973-01-01

    A literature survey and a telephone canvass of producers and users of LOX is reported which yielded one report of an accident resulting from a LOX spill on asphalt, one discussion of hazardous conditions, and an unreferenced mention of an incident. Laboratory tests using standard LOX impact apparatus yielded reactions with both old and new alphalt, but none with concrete. In the final test, using a larger sample of asphalt, the reaction caused extensive damage to equipment. Initial field experiments using 2-meter square asphalt slabs covered with LOX, conducted during rainy weather, achieved no reaction with plummets, and limited reaction with a blasting cap as a reaction initiator. In a final plummet-initiated test on a dry slab, a violent reaction, which appeared to have propagated over the entire slab surface, destroyed the plummet fixture and threw fragments as far as 48 meters.

  2. Tests of highly loaded skids on a concrete runway

    NASA Technical Reports Server (NTRS)

    Stubbs, Sandy M.; Daugherty, Robert H.

    1994-01-01

    Skids have been used at various times for aircraft landing gear ever since the Wright Flyer appeared in the early 1900's. Typically, skids have been employed as aircraft landing gear either at low speeds or at low bearing pressures. Tests were conducted to examine the friction and wear characteristics of various metals sliding on a rough, grooved concrete runway. The metals represented potential materials for an overload protection skid for the Space Shuttle orbiter. Data from tests of six skid specimens conducted at higher speeds and bearing pressures than those of previous tests in the open literature are presented. Skids constructed of tungsten with embedded carbide chips exhibited the lowest wear, whereas a skid constructed of Inconel 718 exhibited high wear rates. Friction coefficients for all the skid specimens were moderate and would provide adequate stopping performance on a long runway. Because of its low wear rate, a skid constructed of tungsten with embedded carbide chips is considered to be a likely candidate for an aircraft skid or overload protection skid.

  3. STS-40 Columbia, OV-102, lands on concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-40 Columbia's, Orbiter Vehicle (OV) 102's, main landing gear (MLG) touches down on concrete runway 22 at Edwards Air Force Base (EAFB), California at 8:29:11 am (Pacific Daylight Time (PDT)). OV-102's starboard side is captured in this profile view as its nose landing gear (NLG) glides above the runway before touch down and wheel stop.

  4. STS-33 Discovery, OV-103, MLG touches down on EAFB concrete runway 04

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Discovery, Orbiter Vehicle (OV) 103, main landing gear (MLG) touchdown is documented at Edwards Air Force Base (EAFB), California, on concrete runway 04. Views look forward from the space shuttle main engines (SSMEs) to the crew compartment as OV-103 glides down the runway. The landing occurred at 16:31:02 pm Pacific Standard Time (PST).

  5. STS-33 Discovery, OV-103, MLG touches down on concrete runway 04 at EAFB

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Discovery, Orbiter Vehicle (OV) 103, main landing gear (MLG) touches down on concrete runway 04 at Edwards Air Force Base (EAFB), California, at 16:31:02 pm Pacific Standard Time (PST). This view captures OV-103's profile (port side) as it glides down the runway.

  6. STS-29 Discovery, OV-103, lands on Edwards AFB concrete runway 22

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, main landing gear (MLG) touches down at a speed of approximately 205 knots (235 miles per hour) on concrete runway 22 at Edwards Air Force Base (AFB), California. Nose landing gear (NLG) is deployed and rides above runway surface prior touchdown. Mojave desert scrub brush appears in the foreground with mountain range appearing in the background.

  7. STS-40 Columbia, OV-102, lands on concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-40 Columbia's, Orbiter Vehicle (OV) 102's, main landing gear (MLG) touches down on concrete runway 22 at Edwards Air Force Base (EAFB), California at 8:29:11 am (Pacific Daylight Time (PDT)). OV-102's port side is captured in this profile view as its nose landing gear (NLG) glides above the runway before touch down and wheel stop.

  8. STS-41 Discovery, OV-103, glides over concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed, glides over concrete runway 22 at Edwards Air Force Base (EAFB), California, prior to touchdown.

  9. STS-31 Discovery, Orbiter Vehicle (OV) 103, lands on EAFB concrete runway 22

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The main landing gear (MLG) of Discovery, Orbiter Vehicle (OV) 103, rides along concrete runway 22 at Edwards Air Force Base (EAFB), California, bringing mission STS-31 to an end. The nose landing gear (NLG) is suspended above the runway prior to touchdown and wheel stop which occurred at 6:51:00 am (Pacific Daylight Time (PDT)). View shows OV-103's starboard side and deployed rudder/speedbrake. EAFB facilities are seen in the distance.

  10. STS-49 Endeavour, OV-105, landing on concrete runway 22 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, glides above concrete runway 22 at Edwards Air Force Base (EAFB), California, just before main landing gear (MLG) touchdown. Nose landing gear (NLG) is also deployed during the landing sequence. Landing occurred at 1:36:38 pm (Pacific Daylight Time (PDT)).

  11. STS-29 Discovery, OV-103, lands on Edwards AFB concrete runway 22

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, main landing gear (MLG) touches down at a speed of approximately 205 knots (235 miles per hour) on concrete runway 22 at Edwards Air Force Base (AFB), California. Nose landing gear (NLG) is deployed and rides above runway surface prior touchdown. Rear view captures OV-103 as it glides past photographer to wheel stop showing the tail section (speedbrake/rudder) and three space shuttle main engines (SSMEs). Mojave desert scrub brush appears in the foreground with aircraft hangar appearing in the background.

  12. STS-41 crew poses in front of OV-103 on concrete runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 crewmembers pose in front of Discovery, Orbiter Vehicle (OV) 103, parked on concrete runway 22 at Edwards Air Force Base (EAFB), California. Having just completed their mission, the crewmembers are still wearing their launch and entry suits (LESs). From left to right are Mission Specialist (MS) Thomas D. Akers, Pilot Robert D. Cabana, Commander Richard N. Richards, MS Bruce E. Melnick, and MS William M. Shepherd.

  13. Plastic (wire-combed) grooving of a slip-formed concrete runway overlay at Patrick Henry Airport: An initial evaluation

    NASA Technical Reports Server (NTRS)

    Marlin, E. C.; Horne, W. B.

    1977-01-01

    A wire-comb technique is described for transversely grooving the surface of a freshly laid (plastic state) slip-formed concrete overlay installed at Patrick Henry Airport. This method of surface texturing yields better water drainage and pavement skid resistance than that obtained with an older conventional burlap drag concrete surface treatment installed on an adjacent portion of the runway.

  14. STS-31 Discovery, Orbiter Vehicle (OV) 103, lands on EAFB concrete runway 22

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-31 Discovery, Orbiter Vehicle (OV) 103, rolls along concrete runway 22 at Edwards Air Force Base (EAFB), California, after nose landing gear (NLG) and main landing gear (MLG) touchdown. This view looks down OV-103's port side from the space shuttle main engines (SSMEs) to the nose section. The SSMEs are gimbaled to their descent position and the rudder/speedbrake is deployed on the vertical stabilizer. Wheel stop occurred at 6:51 am (Pacific Daylight Time (PDT)). In the distance EAFB facilities are visible.

  15. STS-41 crew poses in front of OV-103 on concrete runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 crewmembers give 'thumbs up' signal while standing in front of Discovery, Orbiter Vehicle (OV) 103, parked on concrete runway 22 at Edwards Air Force Base (EAFB), California. Having just completed their mission, the crewmembers are still wearing their launch and entry suits (LESs). From left to right are Mission Specialist (MS) Thomas D. Akers, Pilot Robert D. Cabana, Commander Richard N. Richards, MS Bruce E. Melnick, and MS William M. Shepherd. Set up at OV-103's side hatch is a mobile stairway which the crew uses to egress the vehicle and which technicians use when safing the vehicle during postflight operations.

  16. STS-31 crew poses on EAFB concrete runway after egressing OV-103

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-31 crewmembers, wearing their launch and entry suits (LESs), pose for an informal portrait on Edwards Air Force Base (EAFB) concrete runway 22 after egressing Discovery, Orbiter Vehicle (OV) 103. Left to right are Mission Specialist (MS) Steven A. Hawley, Pilot Charles F. Bolden, MS Kathryn D. Sullivan, Commander Loren J. Shriver, and MS Bruce McCandless II. A service vehicle and OV-103's main landing gear (MLG) are visible in the background. The highly successful five-day mission concluded at EAFB with wheel stop at 6:51:00 am (Pacific Daylight Time (PDT)).

  17. Concrete Materials and Structures

    SciTech Connect

    Wilby, C.B.

    1991-12-31

    Concrete Materials and Structures provides one of the most comprehensive treatments on the topic of concrete engineering. The author covers a gamut of concrete subjects ranging from concrete mix design, basic reinforced concrete theory, prestressed concrete, shell roofs, and two-way slabs-including a through presentation of Hillerborg`s strip method. Prior to Wilby`s book, the scope of these topics would require at least four separate books to cover. With this new book he has succeeded, quite remarkably, in condensing a fairly complete knowledge of concrete engineering into one single easy-to-carry volume.

  18. STS-33 Discovery, OV-103, approaches concrete runway 04 at EAFB, California

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Discovery, Orbiter Vehicle (OV) 103, approaches runway 04 at Edwards Air Force Base (EAFB), California. OV-103 with landing gear deployed is silhouetted against the orange sky of a sunset as it glides over the mountains. The landing occurred at 16:31:02 pm Pacific Standard Time (PST).

  19. Technical Note: Outlays on Construction of Airport Runways with Prestressed and Dowelled Pavements

    NASA Astrophysics Data System (ADS)

    Więckowski, Andrzej; Sznurawa, Alicja

    2015-09-01

    For two variants of runways with abrasive concrete pavements in the prestressed and dowelled technologies, analyses have been presented regarding labour, materials, use of machinery, and financial outlays, together with the necessary technological-organisational analyses and assessment of work execution cycles, by the example of construction of a runway at the Katowice Airport.

  20. Nuclear Concrete Materials Database Phase I Development

    SciTech Connect

    Ren, Weiju; Naus, Dan J

    2012-05-01

    The FY 2011 accomplishments in Phase I development of the Nuclear Concrete Materials Database to support the Light Water Reactor Sustainability Program are summarized. The database has been developed using the ORNL materials database infrastructure established for the Gen IV Materials Handbook to achieve cost reduction and development efficiency. In this Phase I development, the database has been successfully designed and constructed to manage documents in the Portable Document Format generated from the Structural Materials Handbook that contains nuclear concrete materials data and related information. The completion of the Phase I database has established a solid foundation for Phase II development, in which a digital database will be designed and constructed to manage nuclear concrete materials data in various digitized formats to facilitate electronic and mathematical processing for analysis, modeling, and design applications.

  1. Concrete: Potential material for Space Station

    NASA Technical Reports Server (NTRS)

    Lin, T. D.

    1992-01-01

    To build a permanent orbiting space station in the next decade is NASA's most challenging and exciting undertaking. The space station will serve as a center for a vast number of scientific products. As a potential material for the space station, reinforced concrete was studied, which has many material and structural merits for the proposed space station. Its cost-effectiveness depends on the availability of lunar materials. With such materials, only 1 percent or less of the mass of a concrete space structure would have to be transported from earth.

  2. STS-53 Discovery, Orbiter Vehicle (OV) 103, lands on runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-53 Discovery, Orbiter Vehicle (OV) 103, touches down at 12:43:17 pm (Pacific Standard Time (PST)) on concrete runway 22 at Edwards Air Force Base (EAFB), California. A small cloud of dust is produced as the main landing gear (MLG) wheels hit the runway. The nose landing gear (NLG) rides above the runway surface. Desert scrub brush and the runway light fixtures appear in the foreground. Mountains and low-lying clouds are seen in the background.

  3. Status of runway slipperiness research

    NASA Technical Reports Server (NTRS)

    Horne, W. B.

    1976-01-01

    Runway slipperiness research performed in the United States and Europe since 1968 is reviewed. Topics discussed include: (1) runway flooding during rainstorms; (2) hydroplaning; (3) identification of slippery runways including the results from ground vehicle friction measurements and attempts to correlate these measurements with aircraft stopping performance; (4) progress and problems associated with the development of antihydroplaning runway surface treatments such as pavement grooving and porous friction course (PFC); and (5) runway rubber deposits and their removal.

  4. Frost resistance of concrete surfaces coated with waterproofing materials

    NASA Astrophysics Data System (ADS)

    Klovas, A.; Dauksys, M.; Ciuprovaite, G.

    2015-03-01

    Present research lays emphasis on the problem of concrete surface exposed to aggressive surrounding quality. The test was conducted with concrete surfaces coated with different waterproofing materials exposed in solution of 3 % of sodium sulphate. Research was performed according to LST EN 1338:2003 standard requirements. Technological properties of concrete mixture as well as physical-mechanical properties of formed concrete specimens were established. The resistance of concrete to freezing - thawing cycles was prognosticated according to the porosity parameters established by the kinetic of water absorption. Five different waterproofing materials (coatings) such as liquid bitumen-rubber based, elastic fiber-strengthened, silane-siloxane based emulsion, mineral binder based and liquid rubber (caoutchouc) based coatings were used. Losses by mass of coating materials and specimens surface fractures were calculated based on the results of frost resistance test. Open code program "ImageJ" was used for visual analysis of concrete specimens. Based on the results, aggressive surrounding did not influence specimens coated with elastic, fibre-strengthened, mineral materials. On the other hand, specimens coated with liquid rubber (caoutchouc) based material were greatly influenced by aggressive surrounding. The biggest losses of specimen surface concrete (fractures) were obtained with silane-siloxane based emulsion coating. Generally, specimens coated with waterproofing materials were less influenced by aggressive surrounding compared with those without.

  5. STS-53 Discovery, Orbiter Vehicle (OV) 103, lands on runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-53 Discovery, Orbiter Vehicle (OV) 103, lands on concrete runway 22 at Edwards Air Force Base (EAFB), California. Main landing gear (MLG) touchdown occurred at 12:43:17 pm (Pacific Standard Time (PST)). This profile view shows OV-103's starboard side with MLG wheels on the runway and nose landing gear (NLG) riding above the runway. Desert scrub brush appears in the foreground. EAFB hangars and mountains are seen in the background.

  6. STS-48 Discovery, OV-103, lands at night on lit Edwards AFB runway 22

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Spotlights illuminate the approach of STS-48 Discovery, Orbiter Vehicle (OV) 103, above concrete runway 22 at Edwards Air Force Base (EAFB) during its night landing sequence. With nose landing gear (NLG) and main landing gear (MLG) deployed, OV-103 nears touchdown which occurred at 12:38:38 am (Pacific Daylight Time (PDT)). Runway marker '2' is visible in the foreground. OV-103's starboard side glows in the runway lights while the rest of the orbiter blends into the shadowy darkness.

  7. STS-42 Discovery, Orbiter Vehicle (OV) 103, lands on runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-42 Discovery, Orbiter Vehicle (OV) 103, with nose landing gear (NLG) and main landing gear (MLG) deployed glides over concrete runway 22 at Edwards Air Force Base (EAFB), California. Runway lights appear in the foreground and by-standers (observers) and mountains appear in the background.

  8. Use of selected waste materials in concrete mixes

    SciTech Connect

    Batayneh, Malek Marie, Iqbal; Asi, Ibrahim

    2007-07-01

    A modern lifestyle, alongside the advancement of technology has led to an increase in the amount and type of waste being generated, leading to a waste disposal crisis. This study tackles the problem of the waste that is generated from construction fields, such as demolished concrete, glass, and plastic. In order to dispose of or at least reduce the accumulation of certain kinds of waste, it has been suggested to reuse some of these waste materials to substitute a percentage of the primary materials used in the ordinary portland cement concrete (OPC). The waste materials considered to be recycled in this study consist of glass, plastics, and demolished concrete. Such recycling not only helps conserve natural resources, but also helps solve a growing waste disposal crisis. Ground plastics and glass were used to replace up to 20% of fine aggregates in concrete mixes, while crushed concrete was used to replace up to 20% of coarse aggregates. To evaluate these replacements on the properties of the OPC mixes, a number of laboratory tests were carried out. These tests included workability, unit weight, compressive strength, flexural strength, and indirect tensile strength (splitting). The main findings of this investigation revealed that the three types of waste materials could be reused successfully as partial substitutes for sand or coarse aggregates in concrete mixtures.

  9. Strength and failure models for epoxy mortar polymer concrete materials

    SciTech Connect

    Salami, M.R.; Zhao, S.

    1995-06-01

    Since the polymer concrete materials are used in construction, there is a need for developing a fundamental failure and constitutive model for predicting material behavior. The present research is undertaken as an initial step toward developing a fundamental failure and constitutive model for polymer concrete materials, as well as providing benchmark data on the strength and failure characteristics of material specimens for future work. The failure model will be developed based on introducing a failure function. This model will predict the changes in constitutive properties and resistance values in aggressive environments.

  10. Leachability of dissolved chromium in asphalt and concrete surfacing materials.

    PubMed

    Kayhanian, Masoud; Vichare, Akshay; Green, Peter G; Harvey, John

    2009-08-01

    Leachate metal pollutant concentrations produced from different asphalt and concrete pavement surfacing materials were measured under controlled laboratory conditions. The results showed that, in general, the concentrations of most metal pollutants were below the reporting limits. However, dissolved chromium was detected in leachate from concrete (but not asphalt) specimens and more strongly in the early-time leachate samples. As the leaching continued, the concentration of Cr decreased to below or close to the reporting limit. The source of the chromium in concrete pavement was found to be cement. The concentration of total Cr produced from leachate of different cement coming from different sources that was purchased from retail distributors ranged from 124 to 641mug/L. This result indicates that the potential leachability of dissolved Cr from concrete pavement materials can be reduced through source control. The results also showed that the leachability of dissolved Cr in hardened pavement materials was substantially reduced. For example, the concentration of dissolved Cr measured in actual highway runoff was found to be much lower than the Cr concentration produced from leachate of both open and dense graded concrete pavement specimens under controlled laboratory study. It was concluded that pavement materials are not the source of pollutants of concern in roadway runoff; rather most pollutants in roadway surface runoff are generated from other road-use or land-use sources, or from (wet or dry) atmospheric deposition. PMID:19604624

  11. Volcano-related materials in concretes: a comprehensive review.

    PubMed

    Cai, Gaochuang; Noguchi, Takafumi; Degée, Hervé; Zhao, Jun; Kitagaki, Ryoma

    2016-04-01

    Massive volcano-related materials (VRMs) erupted from volcanoes bring the impacts to natural environment and humanity health worldwide, which include generally volcanic ash (VA), volcanic pumice (VP), volcanic tuff (VT), etc. Considering the pozzolanic activities and mechanical characters of these materials, civil engineers propose to use them in low carbon/cement and environment-friendly concrete industries as supplementary cementitious materials (SCMs) or artificial/natural aggregates. The utilization of VRMs in concretes has attracted increasing and pressing attentions from research community. Through a literature review, this paper presents comprehensively the properties of VRMs and VRM concretes (VRMCs), including the physical and chemical properties of raw VRMs and VRMCs, and the fresh, microstructural and mechanical properties of VRMCs. Besides, considering environmental impacts and the development of long-term properties, the durability and stability properties of VRMCs also are summarized in this paper. The former focuses on the resistance properties of VRMCs when subjected to aggressive environmental impacts such as chloride, sulfate, seawater, and freezing-thawing. The latter mainly includes the fatigue, creep, heat-insulating, and expansion properties of VRMCs. This study will be helpful to promote the sustainability in concrete industries, protect natural environment, and reduce the impacts of volcano disaster. Based on this review, some main conclusions are discussed and important recommendations regarding future research on the application of VRMs in concrete industries are provided. PMID:26865491

  12. 14 CFR 151.79 - Runway paving: Second runway; wind conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Runway paving: Second runway; wind...: Second runway; wind conditions. (a) All airports. Paving a second runway on the basis of wind conditions... second runway is oriented with the existing paved runway to achieve the maximum wind coverage, with...

  13. 14 CFR 151.79 - Runway paving: Second runway; wind conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Runway paving: Second runway; wind...: Second runway; wind conditions. (a) All airports. Paving a second runway on the basis of wind conditions... second runway is oriented with the existing paved runway to achieve the maximum wind coverage, with...

  14. 14 CFR 151.79 - Runway paving: Second runway; wind conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Runway paving: Second runway; wind...: Second runway; wind conditions. (a) All airports. Paving a second runway on the basis of wind conditions... second runway is oriented with the existing paved runway to achieve the maximum wind coverage, with...

  15. 14 CFR 151.79 - Runway paving: Second runway; wind conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Runway paving: Second runway; wind...: Second runway; wind conditions. (a) All airports. Paving a second runway on the basis of wind conditions... second runway is oriented with the existing paved runway to achieve the maximum wind coverage, with...

  16. Progress Toward Future Runway Management

    NASA Technical Reports Server (NTRS)

    Lohr, Gary W.; Brown, Sherilyn A.; Atkins, Stephen; Eisenhawer, Stephen W.; Bott, Terrance F.; Long, Dou; Hasan, Shahab

    2011-01-01

    The runway is universally acknowledged as a constraining factor to capacity in the National Airspace System (NAS). It follows that investigation of the effective use of runways, both in terms of selection and assignment, is paramount to the efficiency of future NAS operations. The need to address runway management is not a new idea; however, as the complexities of factors affecting runway selection and usage increase, the need for effective research in this area correspondingly increases. Under the National Aeronautics and Space Administration s Airspace Systems Program, runway management is a key research area. To address a future NAS which promises to be a complex landscape of factors and competing interests among users and operators, effective runway management strategies and capabilities are required. This effort has evolved from an assessment of current practices, an understanding of research activities addressing surface and airspace operations, traffic flow management enhancements, among others. This work has yielded significant progress. Systems analysis work indicates that the value of System Oriented Runway Management tools is significantly increased in the metroplex environment over that of the single airport case. Algorithms have been developed to provide runway configuration recommendations for a single airport with multiple runways. A benefits analysis has been conducted that indicates the SORM benefits include supporting traffic growth, cost reduction as a result of system efficiency, NAS optimization from metroplex operations, fairness in aircraft operations, and rational decision making.

  17. Characterization of gas concrete materials used in buildings of Turkey.

    PubMed

    Damla, N; Cevik, U; Kobya, A I; Celik, A; Van Grieken, R; Kobya, Y

    2009-09-15

    The activity concentration of (226)Ra, (232)Th and (40)K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg(-1), equivalent to a gamma-dose of 1.5 mSv y(-1). Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated. PMID:19297097

  18. Evaluation of high pressure water blast with rotating spray bar for removing paint and rubber deposits from airport runways, and review of runway slipperiness problems created by rubber contamination

    NASA Technical Reports Server (NTRS)

    Horne, W. B.; Griswold, G. D.

    1975-01-01

    A high pressure water blast with rotating spray bar treatment for removing paint and rubber deposits from airport runways is studied. The results of the evaluation suggest that the treatment is very effective in removing above surface paint and rubber deposits to the point that pavement skid resistance is restored to trafficked but uncontaminated runway surface skid resistance levels. Aircraft operating problems created by runway slipperiness are reviewed along with an assessment of the contributions that pavement surface treatments, surface weathering, traffic polishing, and rubber deposits make in creating or alleviating runway slipperiness. The results suggest that conventional surface treatments for both portland cement and asphaltic concrete runways are extremely vulnerable to rubber deposit accretions which can produce runway slipperiness conditions for aircraft operations as or more slippery than many snow and ice-covered runway conditions. Pavement grooving surface treatments are shown to be the least vulnerable to rubber deposits accretion and traffic polishing of the surface treatments examined.

  19. Fundamentals of Concrete and Cement Masonry. Instructional Materials.

    ERIC Educational Resources Information Center

    Hendrix, Laborn J.

    This curriculum guide provides materials for a course of instruction designed for training concrete masons who will make their careers in construction. It contains 4 sections and 18 instructional units in a standard format. Eight basic components that form a unit of instruction are performance objectives, suggested activities for the teacher,…

  20. Bridge deck repairs with polymer concrete patching materials

    NASA Astrophysics Data System (ADS)

    Edgecomb, W. C., Jr.

    1983-01-01

    The FHWA polymer concrete as formulated at Brookhaven National laboratory (BNL) was mixed, placed into spalls and finished on grade with steel trowels on more than a dozen bridges. This polymer concrete was a two-component system consisting of a liquid monomer component comprised of methyl methacrylate base, which contained a cross linking agent with promoters and an inhibitor, and a powder component which contained reactive polymers, blend of silica sands, initiator, and color pigments. These formed an impregnable material of approximately 8000 psi. Cure time for this project's cold weather formulation to obtain this strength was approximately 2 hours at 40 F.

  1. HTGR Base Technology Program. Task 2: concrete properties in nuclear environment. A review of concrete material systems for application to prestressed concrete pressure vessels

    SciTech Connect

    Naus, D.J.

    1981-05-01

    Prestressed concrete pressure vessels (PCPVs) are designed to serve as primary pressure containment structures. The safety of these structures depends on a correct assessment of the loadings and proper design of the vessels to accept these loadings. Proper vessel design requires a knowledge of the component (material) properties. Because concrete is one of the primary constituents of PCPVs, knowledge of its behavior is required to produce optimum PCPV designs. Concrete material systems are reviewed with respect to constituents, mix design, placing, curing, and strength evaluations, and typical concrete property data are presented. Effects of extreme loadings (elevated temperature, multiaxial, irradiation) on concrete behavior are described. Finally, specialty concrete material systems (high strength, fibrous, polymer, lightweight, refractory) are reviewed. 235 references.

  2. Recent Studies of Runway Roughness

    NASA Technical Reports Server (NTRS)

    Morris, Garland; Hall, Albert W.

    1965-01-01

    Recent studies of NASA research related to aircraft operating problems on rough runways are presented. Some of these investigations were conducted cooperatively with the airport operators, with the Federal Aviation Agency, and with the U.S. Air Force. The studies show that criteria based on power spectral levels of runway-profile data are not sufficient to define acceptable levels of runway roughness from the piloting viewpoint. Because of the large variation in response characteristics between various types of aircraft, a runway may be acceptable for some aircraft and unacceptable for others. A criterion for roughness, therefore, should be expressed in terms of aircraft response - preferably, cockpit acceleration. A criterion suggested is that the maximum vertical acceleration in the cockpit should not exceed +/- 0.4 g for sections of the runway where precise aircraft control is required.

  3. Durability of concrete materials in high-magnesium brine

    SciTech Connect

    Wakeley, L.D.; Poole, T.S.; Burkes, J.P.

    1994-03-01

    Cement pastes and mortars representing 11 combinations of candidate concrete materials were cast in the laboratory and monitored for susceptibility to chemical deterioration in high-magnesium brine. Mixtures were selected to include materials included in the current leading candidate concrete for seals at the Waste Isolation Pilot Plant (WIPP). Some materials were included in the experimental matrix to answer questions that had arisen during study of the concrete used for construction of the liner of the WIPP waste-handling shaft. Mixture combinations compared Class C and Class F fly ashes, presence or absence of an expansive component, and presence or absence of salt as a mixture component. Experimental conditions exposed the pastes and mortars to extreme conditions, those being very high levels of Mg ion and an effectively unlimited supply of brine. All pastes and mortars showed deterioration with brine exposure. In general, mortars deteriorated more extensively than the corresponding pastes. Two-inch cube specimens of mortar were not uniformly deteriorated, but showed obvious zoning even after a year in the brine, with a relatively unreacted zone remaining at the center of each cube. Loss of calcium from the calcium hydroxide of paste/aggregate interfaces caused measurable strength loss in the reacted zone comprising the outer portion of every mortar specimen. The current candidate mass concrete for WIPP seals includes salt as an initial component, and has a relatively closed initial microstructure. Both of these features contribute to its suitability for use in large placements within the Salado Formation.

  4. Use of concrete polymer materials in the transportation industry

    SciTech Connect

    Fontana, J J; Bartholomew, J

    1980-01-01

    Under contract to the FHWA, Brookhaven National Laboratory has developed a polymer concrete patching material that combines the premix characteristics of PCC with strength and durability properties that are higher than PCC. PC overlays have been shown to be highly impermeable to water and chlorides. Laydown techniques have been developed to allow bridge maintenance crews to place the overlays with little or no problems. Today several manufacturers are marketing PC materials, and their acceptance is becoming widespread.

  5. Crushed cement concrete substitution for construction aggregates; a materials flow analysis

    USGS Publications Warehouse

    Kelly, Thomas

    1998-01-01

    An analysis of the substitution of crushed cement concrete for natural construction aggregates is performed by using a materials flow diagram that tracks all material flows into and out of the cement concrete portion of the products made with cement concrete: highways, roads, and buildings. Crushed cement concrete is only one of the materials flowing into these products, and the amount of crushed cement concrete substituted influences the amount of other materials in the flow. Factors such as availability and transportation costs, as well as physical properties, that can affect stability and finishability, influence whether crushed cement concrete or construction aggregates should be used or predominate for a particular end use.

  6. Runway configuration improvement programming model.

    NASA Technical Reports Server (NTRS)

    Yu, J. C.; Gibson, D. R.

    1973-01-01

    The basic objectives of the study were to subject a set of runway configurations to cost analysis and to develop a dynamic programming model which would enable an airport to economically match the ground capacity to its air traffic demand. Quantitative differences in the capacity of runway configurations result from the various aircraft/aircraft and aircraft/air-system interactions. A problem formulation and solution procedure is presented which is intended to be a meaningful technique for the long-range planning of runway expansion programs.

  7. Shuttle landing runway modification to improve tire spin-up wear performance

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Yager, Thomas J.; Stubbs, Sandy M.

    1988-01-01

    This paper presents the results of a series of tire spin-up wear tests on a simulated Kennedy Space Center (KSC) runway that were carried out to investigate the tire wear problem for Space Shuttle landings on the KSC runway and to test several modifications of the runway surface designed to alleviate the problem. It was found that the runway surface produced by a concrete smoothing machine using cutters spaced one and three-quarters blades per centimeter provided adequate wet cornering while limiting spin-up wear. Based on the test results, the KSC runway was smoothed for about 1066 m at each end, leaving the original high friction surface, for better wet steering and braking, in the 2438-m central section.

  8. Runway Safety Monitor Algorithm for Runway Incursion Detection and Alerting

    NASA Technical Reports Server (NTRS)

    Green, David F., Jr.; Jones, Denise R. (Technical Monitor)

    2002-01-01

    The Runway Safety Monitor (RSM) is an algorithm for runway incursion detection and alerting that was developed in support of NASA's Runway Incursion Prevention System (RIPS) research conducted under the NASA Aviation Safety Program's Synthetic Vision System element. The RSM algorithm provides pilots with enhanced situational awareness and warnings of runway incursions in sufficient time to take evasive action and avoid accidents during landings, takeoffs, or taxiing on the runway. The RSM currently runs as a component of the NASA Integrated Display System, an experimental avionics software system for terminal area and surface operations. However, the RSM algorithm can be implemented as a separate program to run on any aircraft with traffic data link capability. The report documents the RSM software and describes in detail how RSM performs runway incursion detection and alerting functions for NASA RIPS. The report also describes the RIPS flight tests conducted at the Dallas-Ft Worth International Airport (DFW) during September and October of 2000, and the RSM performance results and lessons learned from those flight tests.

  9. Characterization of concrete materials by using stress wave NDE techniques

    NASA Astrophysics Data System (ADS)

    Sadri, Afshin; deWalle, Brian

    1999-12-01

    A new instrument for monitoring the quality of concrete materials has been developed by Andec Mfg. Ltd. This new instrument, the AndeScope, can be used to evaluate concrete materials by measuring the stress wave velocity, dynamic elastic constant, quality factor (Q-factor), signal frequency, and decay coefficient. The AndeScope can be used to estimate the strength gain at the setting time, or it can be used to diagnose problems such as Alkali-Silica Reaction (ASR) or micro fracturing. The three stress wave propagation techniques are used in combination for this evaluation: ultrasonic through-transmission, pulse-echo and impact-echo. The ultrasonic through-transmission technique uses a direct arrangement between the transmitting and receiving transducers, while the pulse-echo and impact-echo technique are used to monitor concrete materials and structures from a single available face. The AndeScope's three stress wave modes can also be used to detect flaws, delamination, thickness, honeycombing, and crack depth measurements. In this paper, the principles of the three stress wave techniques and actual functions of the instrument are described. The advantages and disadvantages of each technique and new methodologies are discussed.

  10. The use of waste materials in asphalt concrete mixtures.

    PubMed

    Tuncan, Mustafa; Tuncan, Ahmet; Cetin, Altan

    2003-04-01

    The purpose of this study was to investigate (a) the effects of rubber and plastic concentrations and rubber particle sizes on properties of asphalt cement, (b) on properties of asphalt concrete specimens and (c) the effects of fly ash, marble powder, rubber powder and petroleum contaminated soil as filler materials instead of stone powder in the asphalt concrete specimens. One type of limestone aggregate and one penetration-graded asphalt cement (75-100) were used. Three concentrations of rubber and plastic (i.e. 5%, 10% and 20% of the total weight of asphalt cement), three rubber particle sizes (i.e. No. 4 [4.75mm] - 20 [0.85 mm], No. 20 [0.85mm] - 200 [0.075mm] and No. 4 [4.75mm] - 200 [0.075mm]) and one plastic particle size (i.e. No. 4 [4.75mm] - 10 [2.00mm]) were also used. It was found that while the addition of plastic significantly increased the strength of specimens, the addition of rubber decreased it. No. 4 [4.75mm] - 200 [0.075mm] rubber particles showed the best results with respect to the indirect tensile test. The Marshall stability and indirect tensile strength properties of plastic modified specimens increased. Marble powder and fly ash could be used as filler materials instead of stone powder in the asphalt concrete pavement specimens. PMID:12739723

  11. The Effect of Elevated Temperature on Concrete Materials and Structures - a Literature Review.

    SciTech Connect

    Naus, Dan J

    2006-03-01

    The objective of this limited study was to provide an overview of the effects of elevated temperature on the behavior of concrete materials and structures. In meeting this objective the effects of elevated temperatures on the properties of ordinary Portland cement concrete constituent materials and concretes are summarized. The effects of elevated temperature on high-strength concrete materials are noted and their performance compared to normal strength concretes. A review of concrete materials for elevated-temperature service is presented. Nuclear power plant and general civil engineering design codes are described. Design considerations and analytical techniques for evaluating the response of reinforced concrete structures to elevated-temperature conditions are presented. Pertinent studies in which reinforced concrete structural elements were subjected to elevated temperatures are described.

  12. Alternate anode materials for cathodic protection of steel reinforced concrete

    SciTech Connect

    Russell, James H.; Bullard, Sophie J.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Cryer, Curtis B.

    2001-01-01

    Consumable and non-consumable anodes were evaluated in the laboratory for use in cathodic protection (CP) systems for steel reinforced concrete bridges in coastal environments and in areas where deicing salts are employed. The anode materials included Zn-hydrogel and thermal-sprayed Zn, Zn-15Al, Al-12Zn-0.2In, and cobalt-sprayed Ti. These anodes were evaluated for service in both galvanic (GCP) and impressed current (ICCP) cathodic protection systems. Impressed current CP anodes were electrochemically aged at a current density 15 times as great as that used by the Oregon Department of Transportation in typical coastal ICCP systems (2.2 mA/m2 based on anode area). Increasing moisture at the anode-concrete interface reduced the operating voltage of all the anodes. Bond strength between the anodes and concrete decreased with electrochemical aging. The Zn-15Al and Al-12Zn-0.2In anodes provided adequate protection in GCP but their life was too short in the accelerated ICCP tests. Zinc had an adequate life in ICCP tests but was inadequate as a galvanic anode. Zinc-hydrogel performed well in both tests when the hydrogel was kept moist. Titanium was an excellent anode for ICCP, but is not suitable for GCP.

  13. Tire and runway surface research

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1986-01-01

    The condition of aircraft tires and runway surfaces can be crucial in meeting the stringent demands of aircraft ground operations, particularly under adverse weather conditions. Gaining a better understanding of the factors influencing the tire/pavement interface is the aim of several ongoing NASA Langley research programs which are described in this paper. Results from several studies conducted at the Langley Aircraft Landing Dynamics Facility, tests with instrumented ground vehicles and aircraft, and some recent aircraft accident investigations are summarized to indicate effects of different tire and runway properties. The Joint FAA/NASA Runway Friction Program is described together with some preliminary test findings. The scope of future NASA Langley research directed towards solving aircraft ground operational problems related to the tire/pavement interface is given.

  14. Runway drainage characteristics related to tire friction performance

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1991-01-01

    The capability of a runway pavement to rapidly drain water buildup during periods of precipitation is crucial to minimize tire hydroplaning potential and maintain adequate aircraft ground operational safety. Test results from instrumented aircraft, ground friction measuring vehicles, and NASA Langley's Aircraft Landing Dynamics Facility (ALDF) track have been summarized to indicate the adverse effects of pavement wetness conditions on tire friction performance. Water drainage measurements under a range of rainfall rates have been evaluated for several different runway surface treatments including the transversely grooved and longitudinally grinded concrete surfaces at the Space Shuttle Landing Facility (SLF) runway at NASA Kennedy Space Center in Florida. The major parameters influencing drainage rates and extent of flooding/drying conditions are identified. Existing drainage test data are compared to a previously derived empirical relationship and the need for some modification is indicated. The scope of future NASA Langley research directed toward improving empirical relationships to properly define runway drainage capability and consequently, enhance aircraft ground operational safety, is given.

  15. 14 CFR 151.80 - Runway paving: Additional runway; other conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Runway paving: Additional runway; other conditions. 151.80 Section 151.80 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.80 Runway paving: Additional runway; other...

  16. A failure criterion for polymer concrete material considering the effect of temperature

    SciTech Connect

    Zhao, S.; Salami, M.R.

    1995-06-01

    Knowledge of the basic constitutive properties of the concrete materials is needed to analyze service load characteristics, design and evaluate strengths. In this study, a constitutive model which considers the effect of temperature will be proposed for polymer concrete materials. The genetic algorithm is used to find some material constants. The results are verified by back-prediction.

  17. Aerial view of Runway 33 at SLF

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This aerial view shows the approach on Runway 33 at the KSC Shuttle Landing Facility. The runway is 15,000 feet long, with 1,000-foot paved overruns at each end; 300 feet wide (about length of football field), with 50-foot asphalt shoulders each side; 16 inches thick in the center, and 15 inches thick on sides. It has a slope of 24 inches from the center line to the edge for drainage. The single landing strip is considered two runways, depending on approach -- Runway 15 from northwest, Runway 33 from southeast.

  18. Applying Grounded Coordination Challenges to Concrete Learning Materials: A Study of Number Line Estimation

    ERIC Educational Resources Information Center

    Vitale, Jonathan M.; Black, John B.; Swart, Michael I.

    2014-01-01

    Do concrete learning materials promote strong learning outcomes, or do they simply make learning tasks more initially accessible? Although concrete materials may offer an intuitive foothold on a topic, research on desirable difficulties suggests that more challenging tasks facilitate greater retention and transfer. In the approach introduced here,…

  19. Concrete material characterization reinforced concrete tank structure Multi-Function Waste Tank Facility

    NASA Astrophysics Data System (ADS)

    Winkel, B. V.

    1995-03-01

    The purpose of this report is to document the Multi-Function Waste Tank Facility (MWTF) Project position on the concrete mechanical properties needed to perform design/analysis calculations for the MWTF secondary concrete structure. This report provides a position on MWTF concrete properties for the Title 1 and Title 2 calculations. The scope of the report is limited to mechanical properties and does not include the thermophysical properties of concrete needed to perform heat transfer calculations. In the 1970's, a comprehensive series of tests were performed at Construction Technology Laboratories (CTL) on two different Hanford concrete mix designs. Statistical correlations of the CTL data were later generated by Pacific Northwest Laboratories (PNL). These test results and property correlations have been utilized in various design/analysis efforts of Hanford waste tanks. However, due to changes in the concrete design mix and the lower range of MWTF operating temperatures, plus uncertainties in the CTL data and PNL correlations, it was prudent to evaluate the CTL data base and PNL correlations, relative to the MWTF application, and develop a defendable position. The CTL test program for Hanford concrete involved two different mix designs: a 3 kip/sq in mix and a 4.5 kip/sq in mix. The proposed 28-day design strength for the MWTF tanks is 5 kip/sq in. In addition to this design strength difference, there are also differences between the CTL and MWTF mix design details. Also of interest, are the appropriate application of the MWTF concrete properties in performing calculations demonstrating ACI Code compliance. Mix design details and ACI Code issues are addressed in Sections 3.0 and 5.0, respectively. The CTL test program and PNL data correlations focused on a temperature range of 250 to 450 F. The temperature range of interest for the MWTF tank concrete application is 70 to 200 F.

  20. Concrete material characterization reinforced concrete tank structure Multi-Function Waste Tank Facility

    SciTech Connect

    Winkel, B.V.

    1995-03-03

    The purpose of this report is to document the Multi-Function Waste Tank Facility (MWTF) Project position on the concrete mechanical properties needed to perform design/analysis calculations for the MWTF secondary concrete structure. This report provides a position on MWTF concrete properties for the Title 1 and Title 2 calculations. The scope of the report is limited to mechanical properties and does not include the thermophysical properties of concrete needed to perform heat transfer calculations. In the 1970`s, a comprehensive series of tests were performed at Construction Technology Laboratories (CTL) on two different Hanford concrete mix designs. Statistical correlations of the CTL data were later generated by Pacific Northwest Laboratories (PNL). These test results and property correlations have been utilized in various design/analysis efforts of Hanford waste tanks. However, due to changes in the concrete design mix and the lower range of MWTF operating temperatures, plus uncertainties in the CTL data and PNL correlations, it was prudent to evaluate the CTL data base and PNL correlations, relative to the MWTF application, and develop a defendable position. The CTL test program for Hanford concrete involved two different mix designs: a 3 kip/in{sup 2} mix and a 4.5 kip/in{sup 2} mix. The proposed 28-day design strength for the MWTF tanks is 5 kip/in{sup 2}. In addition to this design strength difference, there are also differences between the CTL and MWTF mix design details. Also of interest, are the appropriate application of the MWTF concrete properties in performing calculations demonstrating ACI Code compliance. Mix design details and ACI Code issues are addressed in Sections 3.0 and 5.0, respectively. The CTL test program and PNL data correlations focused on a temperature range of 250 to 450 F. The temperature range of interest for the MWTF tank concrete application is 70 to 200 F.

  1. NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

    NASA Technical Reports Server (NTRS)

    Horne, W. B.

    1977-01-01

    Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

  2. Tire/runway friction interface

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1990-01-01

    An overview is given of NASA Langley's tire/runway pavement interface studies. The National Tire Modeling Program, evaluation of new tire and landing gear designs, tire wear and friction tests, and tire hydroplaning studies are examined. The Aircraft Landing Dynamics Facility is described along with some ground friction measuring vehicles. The major goals and scope of several joint FAA/NASA programs are identified together with current status and plans.

  3. Effect of different supplementary cementitious materials on mechanical properties of high performance concrete

    SciTech Connect

    Khatri, R.P.; Sirivivatnanon, V. . Div. of Building, Construction and Engineering); Gross, W. . Readymix Group)

    1995-01-01

    High performance concrete prepared from general purpose (GP) portland cement and various supplementary cementitious materials are increasingly finding their use in construction worldwide. This study was undertaken to compare mechanical properties as well as fresh concrete properties of concretes containing silica fume, ground granulated blast furnace slag (slag), fly ash and GP portland cement. The aim of the study was to enable evaluation of the suitability of a particular binder system for an application based on fresh concrete properties and mechanical properties. Concrete mixes were prepared with GP portland cement, high slag cement and slag cement, and also mixes were prepared with the addition of silica fume and fly ash. The work focused on concrete mixes having a fixed water/binder ratio of 0.35 and a constant total binder content of 430 kg/m[sup 3]. Apart from measuring fresh concrete properties, the mechanical properties evaluated were development of compressive strength, flexural strength, elastic modulus, and strain due to creep and drying shrinkage. Results indicated that the addition of silica fume to GP portland cement concrete marginally decreased the workability of the concrete but significantly improved the mechanical properties. However, the effect of addition of silica fume to high slag cement concrete was less pronounced.

  4. Pilot Evaluations of Runway Status Light System

    NASA Technical Reports Server (NTRS)

    Young, Steven D.; Wills, Robert W.; Smith, R. Marshall

    1996-01-01

    This study focuses on use of the Transport Systems Research Vehicle (TSRV) Simulator at the Langley Research Center to obtain pilot opinion and input on the Federal Aviation Administration's Runway Status Light System (RWSL) prior to installation in an operational airport environment. The RWSL has been designed to reduce the likelihood of runway incursions by visually alerting pilots when a runway is occupied. Demonstrations of the RWSL in the TSRV Simulator allowed pilots to evaluate the system in a realistic cockpit environment.

  5. 14 CFR 151.79 - Runway paving: Second runway; wind conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Runway paving: Second runway; wind conditions. 151.79 Section 151.79 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.79 Runway...

  6. 14 CFR 151.80 - Runway paving: Additional runway; other conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Runway paving: Additional runway; other conditions. 151.80 Section 151.80 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.80 Runway...

  7. 14 CFR 151.80 - Runway paving: Additional runway; other conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Runway paving: Additional runway; other conditions. 151.80 Section 151.80 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.80 Runway...

  8. 14 CFR 151.80 - Runway paving: Additional runway; other conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Runway paving: Additional runway; other conditions. 151.80 Section 151.80 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.80 Runway...

  9. 14 CFR 151.80 - Runway paving: Additional runway; other conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Runway paving: Additional runway; other conditions. 151.80 Section 151.80 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.80 Runway...

  10. 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.

  11. Analysis of Runway Incursion Data

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.

    2013-01-01

    A statistical analysis of runway incursion (RI) events was conducted to ascertain relevance to the top ten challenges of the National Aeronautics and Space Administration Aviation Safety Program (AvSP). The information contained in the RI database was found to contain data that may be relevant to several of the AvSP top ten challenges. When combined with other data from the FAA documenting air traffic volume from calendar year 2000 through 2011, the structure of a predictive model emerges that can be used to forecast the frequency of RI events at various airports for various classes of aircraft and under various environmental conditions.

  12. Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

    NASA Astrophysics Data System (ADS)

    Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie

    2014-04-01

    Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.

  13. Current Practices in Runway Configuration Management (RCM) and Arrival/Departure Runway Balancing (ADRB)

    NASA Technical Reports Server (NTRS)

    Lohr, Gary W.; Williams, Daniel M.

    2008-01-01

    Significant air traffic increases are anticipated for the future of the National Airspace System (NAS). To cope with future traffic increases, fundamental changes are required in many aspects of the air traffic management process including the planning and use of NAS resources. Two critical elements of this process are the selection of airport runway configurations, and the effective management of active runways. Two specific research areas in NASA's Airspace Systems Program (ASP) have been identified to address efficient runway management: Runway Configuration Management (RCM) and Arrival/Departure Runway Balancing (ADRB). This report documents efforts in assessing past as well as current work in these two areas.

  14. STS-57 Endeavour, OV-105, glides above KSC SLF runway 33 prior to landing

    NASA Technical Reports Server (NTRS)

    1993-01-01

    With main landing gear (MLG) and nose landing gear (NLG) deployed, Endeavour, Orbiter Vehicle (OV) 105, is captured just before touchdown on concrete runway 33 at the Kennedy Space Center's (KSC's) Shuttle Landing Facility (SLF). The shuttle trainer aircraft (STA) monitors the STS-57 landing as it flies overhead. Moments after this picture was taken, MLG touched down at 8:52:16am (Eastern Daylight Time (EDT)). In the foreground are a waterway, grasses, and runway lights and markers. The view looks down OV-105's port side.

  15. STS-53 Discovery, Orbiter Vehicle (OV) 103, lands on runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-53 Discovery, Orbiter Vehicle (OV) 103, is slowed by a red, white, and blue drag chute during its landing on concrete runway 22 at Edwards Air Force Base (EAFB), California. Main landing gear (MLG) touchdown occurred at 12:43:17 pm (Pacific Standard Time (PST)). This aft view of OV-103 shows the drag chute deployed from its compartment at the base of the vertical tail, the speedbrake/rudder flaps open, and the space shuttle main engines (SSMEs). Both MLG and nose landing gear (NLG) ride along the runway surface. Desert scrub brush appears in the foreground and mountains are seen in the background.

  16. STS-53 Discovery, Orbiter Vehicle (OV) 103, lands on runway 22 at EAFB, Calif

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-53 Discovery, Orbiter Vehicle (OV) 103, rides along concrete runway 22 at Edwards Air Force Base (EAFB), California, as the red, white, and blue drag chute unfurls behind it. Nose landing gear (NLG) wheels are inches above the runway surface as the main landing gear (MLG) wheels roll along it. MLG touchdown occurred at 12:43:17 pm (Pacific Standard Time (PST)).This head-on view looks down OV-103's port side. The speedbrake/rudder flaps are deployed as the drag chute opens behind the vehicle. Desert scrub brush appears in the foreground and mountains are seen in the background.

  17. Wet runways. [aircraft landing and directional control

    NASA Technical Reports Server (NTRS)

    Horne, W. B.

    1975-01-01

    Aircraft stopping and directional control performance on wet runways is discussed. The major elements affecting tire/ground traction developed by jet transport aircraft are identified and described in terms of atmospheric, pavement, tire, aircraft system and pilot performance factors or parameters. Research results are summarized, and means for improving or restoring tire traction/aircraft performance on wet runways are discussed.

  18. Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction

    SciTech Connect

    Ostowari, Ken; Nosson, Ali

    2000-09-30

    The project developed high-recycled-content concrete material with balanced structural and thermal attributes for use in energy-efficient building construction. Recycled plastics, tire, wool, steel and concrete were used as replacement for coarse aggregates in concrete and masonry production. With recycled materials the specific heat and thermal conductivity of concrete could be tailored to enhance the energy-efficiency of concrete buildings. A comprehensive field project was implemented which confirmed the benefits of high-recycled-content concrete for energy-efficient building construction.

  19. Spot and Runway Departure Advisor

    NASA Technical Reports Server (NTRS)

    Jung, Yoon Chul

    2013-01-01

    The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

  20. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  1. Utility of Wastage Material as Steel Fibre in Concrete Mix M-20

    NASA Astrophysics Data System (ADS)

    Parashar, Ashish Kumar; Parashar, Rinku

    2012-10-01

    Fiber Reinforced Concrete (FRC) is a composite material consisting of cement based matrix with an ordered or random distribution of fiber which can be steel, nylon, polythene etc. The addition of steel fibre increases the properties of concrete, viz., flexural strength, impact strength and shrinkage properties to name a few. A number of papers have already been published on the use of steel fibres in concrete and a considerable amount of research has been directed towards studying the various properties of concrete as well as reinforced concrete due to the addition of steel fibres. Hence, an attempt has been made in the present investigations to study the influence of addition of Lathe Machines wastematerial as fibers at a dosage of 5% to 30% by weight of cement. The properties studied include compressive strength. The studies were conducted on a M20 mix and tests have been carried out. The results are compared and conclusions are made.

  2. Evaluation of Sulfur 'Concrete' for Use as a Construction Material on the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.

    2008-01-01

    Combining molten sulfur with any number of aggregate materials forms, when solid, a mixture having attributes similar, if not better, to conventional water-based concrete. As a result the use of sulfur "concrete" on Earth is well established, particularly in corrosive environments. Consequently, discovery of troilite (FeS) on the lunar surface prompted numerous scenarios about its reduction to elemental sulfur for use, in combination with lunar regolith, as a potential construction material; not requiring water, a precious resource, for its manufacture is an obvious advantage. However, little is known about the viability of sulfur concrete in an environment typified by extreme temperatures and essentially no atmosphere. The experimental work presented here evaluates the response of pure sulfur and sulfur concrete subjected to laboratory conditions that approach those expected on the lunar surface, the results suggesting a narrow window of application.

  3. System Oriented Runway Management: A Research Update

    NASA Technical Reports Server (NTRS)

    Lohr, Gary W.; Brown, Sherilyn A.; Stough, Harry P., III; Eisenhawer, Steve; Atkins, Stephen; Long, Dou

    2011-01-01

    The runway configuration used by an airport has significant implications with respect to its capacity and ability to effectively manage surface and airborne traffic. Aircraft operators rely on runway configuration information because it can significantly affect an airline's operations and planning of their resources. Current practices in runway management are limited by a relatively short time horizon for reliable weather information and little assistance from automation. Wind velocity is the primary consideration when selecting a runway configuration; however when winds are below a defined threshold, discretion may be used to determine the configuration. Other considerations relevant to runway configuration selection include airport operator constraints, weather conditions (other than winds) traffic demand, user preferences, surface congestion, and navigational system outages. The future offers an increasingly complex landscape for the runway management process. Concepts and technologies that hold the potential for capacity and efficiency increases for both operations on the airport surface and in terminal and enroute airspace are currently under investigation. Complementary advances in runway management are required if capacity and efficiency increases in those areas are to be realized. The System Oriented Runway Management (SORM) concept has been developed to address this critical part of the traffic flow process. The SORM concept was developed to address all aspects of runway management for airports of varying sizes and to accommodate a myriad of traffic mixes. SORM, to date, addresses the single airport environment; however, the longer term vision is to incorporate capabilities for multiple airport (Metroplex) operations as well as to accommodate advances in capabilities resulting from ongoing research. This paper provides an update of research supporting the SORM concept including the following: a concept of overview, results of a TRCM simulation, single

  4. Runway Incursion Prevention for General Aviation Operations

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Prinzel, Lawrence J., III

    2006-01-01

    A Runway Incursion Prevention System (RIPS) and additional incursion detection algorithm were adapted for general aviation operations and evaluated in a simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) in the fall of 2005. RIPS has been designed to enhance surface situation awareness and provide cockpit alerts of potential runway conflicts in order to prevent runway incidents while also improving operational capability. The purpose of the study was to evaluate the airborne incursion detection algorithms and associated alerting and airport surface display concepts for general aviation operations. This paper gives an overview of the system, simulation study, and test results.

  5. Electronic System for Preventing Airport Runway Incursions

    NASA Technical Reports Server (NTRS)

    Dabney, Richard; Elrod, Susan

    2009-01-01

    A proposed system of portable illuminated signs, electronic monitoring equipment, and radio-communication equipment for preventing (or taking corrective action in response to) improper entry of aircraft, pedestrians, or ground vehicles onto active airport runways is described. The main overall functions of the proposed system would be to automatically monitor aircraft ground traffic on or approaching runways and to generate visible and/or audible warnings to affected pilots, ground-vehicle drivers, and control-tower personnel when runway incursions take place.

  6. 14 CFR 151.11 - Runway clear zones; requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... zone areas (in connection with initial land acquisition) for all eligible runways or landing strips... runways or landing strips are developed, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas for each runway and landing strip to be developed or...

  7. 14 CFR 151.11 - Runway clear zones; requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... zone areas (in connection with initial land acquisition) for all eligible runways or landing strips... runways or landing strips are developed, the sponsor must own, acquire, or agree to acquire adequate property interests in runway clear zone areas for each runway and landing strip to be developed or...

  8. Performance of Styrene Butadiene Rubber as a Concrete Repair Material in tropical climate

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, R.; Prakash, V. Syam; Thampan, C. K.; Varma, Prasad

    2012-11-01

    Deterioration of Concrete due to variety of reasons like corrosion of steel, inferior quality of materials as well as workmanship and exposure to aggressive environment like thermal cycling affect the performance or damage a number of Reinforced cement concrete structures. In order to repair these structures for enhancing the service life, number of methods and materials are available. But the degree of success of any repair in concrete depends mainly on the correct choice and the method of application of repair materials. This paper discusses the details of an experimental investigation on the performance of Styrene ñ Butadiene Rubber (SBR) as a concrete repair material in tropical climatic conditions. Resistance to water penetration and tensile cracking are two important performance criteria for any repair material. Cement mortar cubes of mix proportion 1:3 with SBR added at the rate of 20% of the weight of cement, and control specimens without SBR were made. Compressive strength and sorptivity values of the cubes were determined. Shear Bond strength (by slant shear test) and splitting tensile strength of the repaired cylinder specimens of standard dimensions, in which SBR used as a bonding agent were determined. These values were compared with the values obtained for the similar specimens, in which the bonding agent applied was conventional cement slurry. The influence of thermal cycling on the properties of repaired concrete specimens were also studied. A comparison has also been made with the values required to meet the standard specifications of a repair material.

  9. Runway Safety Monitor Algorithm for Single and Crossing Runway Incursion Detection and Alerting

    NASA Technical Reports Server (NTRS)

    Green, David F., Jr.

    2006-01-01

    The Runway Safety Monitor (RSM) is an aircraft based algorithm for runway incursion detection and alerting that was developed in support of NASA's Runway Incursion Prevention System (RIPS) research conducted under the NASA Aviation Safety and Security Program's Synthetic Vision System project. The RSM algorithm provides warnings of runway incursions in sufficient time for pilots to take evasive action and avoid accidents during landings, takeoffs or when taxiing on the runway. The report documents the RSM software and describes in detail how RSM performs runway incursion detection and alerting functions for NASA RIPS. The report also describes the RIPS flight tests conducted at the Reno/Tahoe International Airport (RNO) and the Wallops Flight Facility (WAL) during July and August of 2004, and the RSM performance results and lessons learned from those flight tests.

  10. Spot and Runway Departure Advisor (SARDA)

    NASA Technical Reports Server (NTRS)

    Jung, Yoon

    2016-01-01

    Spot and Runway Departure Advisor (SARDA) is a decision support tool to assist airline ramp controllers and ATC tower controllers to manage traffic on the airport surface to significantly improve efficiency and predictability in surface operations. The core function of the tool is the runway scheduler which generates an optimal solution for runway sequence and schedule of departure aircraft, which would minimize system delay and maximize runway throughput. The presentation also discusses the latest status of NASA's current surface research through a collaboration with an airline partner, where a tool is developed for airline ramp operators to assist departure pushback operations. The presentation describes the concept of the SARDA tool and results from human-in-the-loop simulations conducted in 2012 for Dallas-Ft. Worth International Airport and 2014 for Charlotte airport ramp tower.

  11. Effect of Uncertainty on Deterministic Runway Scheduling

    NASA Technical Reports Server (NTRS)

    Gupta, Gautam; Malik, Waqar; Jung, Yoon C.

    2012-01-01

    Active runway scheduling involves scheduling departures for takeoffs and arrivals for runway crossing subject to numerous constraints. This paper evaluates the effect of uncertainty on a deterministic runway scheduler. The evaluation is done against a first-come- first-serve scheme. In particular, the sequence from a deterministic scheduler is frozen and the times adjusted to satisfy all separation criteria; this approach is tested against FCFS. The comparison is done for both system performance (throughput and system delay) and predictability, and varying levels of congestion are considered. The modeling of uncertainty is done in two ways: as equal uncertainty in availability at the runway as for all aircraft, and as increasing uncertainty for later aircraft. Results indicate that the deterministic approach consistently performs better than first-come-first-serve in both system performance and predictability.

  12. TRIZ Tool for Optimization of Airport Runway

    NASA Astrophysics Data System (ADS)

    Rao, K. Venkata; Selladurai, V.; Saravanan, R.

    TRIZ tool is used for conceptual design and layout of the novel ascending and descending runway model for the effective utilization of short length airports. Handling bigger aircrafts at smaller airports become the necessity for economic consideration and for the benefit of vast airliners and the aspiring air travelers of the region. The authors’ proposal of ascending and descending runway would enable the operational need of wide body aircrafts such as Boeing 747 and Airbus A380-800. Negotiating take-off and landing of bigger aircrafts at less than 10000 feet runway is an optimization solution. This conceptual model and the theoretical design with its layout is dealt in this paper as Part - I. The computer-aided design and analysis using MATLAB with Simulink tool box to confirm the adequacy of the runway length for the bigger aircrafts at smaller airports is however dealt in subsequent papers.

  13. BUILDING MATERIAL CHARACTERIZATION USING A CONCRETE FLOOR AND WALL CONTAMINATION PROFILING TECHNOLOGY

    SciTech Connect

    Aggarwal, Dr. S.,; Charters, G.; Thacker, Dr. D.

    2003-02-27

    Certain radioisotopes can penetrate concrete and contaminate the concrete well below the surface. The challenge is to determine the extent and magnitude of the contamination problem in real-time. The concrete profiling technology, TRUPROSM in conjunction with portable radiometric instrumentation produces a profile of radiological or chemical contamination through the material being studied. The data quality, quantity, and representativeness may be used to produce an activity profile from the hot spot surface into the material being sampled. This activity profile may then be expanded to ultimately characterize the facility and expedite waste segregation and facility closure at a reduced cost and risk. Performing a volumetric concrete or metal characterization safer and faster (without lab intervention) is the objective of this characterization technology. This way of determining contamination can save considerable time and money. Currently, concrete core bores are shipped to certified laboratories where the concrete residue is run through a battery of tests to determine the contaminants. The existing core boring operation volatilizes or washes out some of the contaminants (like tritium) and oftentimes cross-contaminates the area around the core bore site. The volatilization of the contaminants can lead to airborne problems in the immediate vicinity of the core bore. Cross-contamination can increase the contamination area and thereby increase the amount of waste generated. The goal is to avoid those field activities that could cause this type of release.

  14. Photocatalytic activity of titanium dioxide modified concrete materials - influence of utilizing recycled glass cullets as aggregates.

    PubMed

    Chen, Jun; Poon, Chi-Sun

    2009-08-01

    Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material - Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing. PMID:19540649

  15. Joint Winter Runway Friction Program Accomplishments

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Wambold, James C.; Henry, John J.; Andresen, Arild; Bastian, Matthew

    2002-01-01

    The major program objectives are: (1) harmonize ground vehicle friction measurements to report consistent friction value or index for similar contaminated runway conditions, for example, compacted snow, and (2) establish reliable correlation between ground vehicle friction measurements and aircraft braking performance. Accomplishing these objectives would give airport operators better procedures for evaluating runway friction and maintaining acceptable operating conditions, providing pilots information to base go/no go decisions, and would contribute to reducing traction-related aircraft accidents.

  16. Triaxial testing of polymer concrete materials under different temperature

    SciTech Connect

    Salami, M.R.; Zhao, S.

    1995-06-01

    Since polymer mortar materials are used in construction, there is a need for an accurate material model to predict the behavior of the materials under various loading conditions. To make use of a material failure model, it is necessary to determine the material constants by conducting laboratory tests on material specimens. To find the constants for a failure model the material will be subjected to static load testing at different temperatures and loading rates.

  17. FINAL REPORT: REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    EPA Science Inventory

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. To improve current practice in identifying ha...

  18. REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    EPA Science Inventory

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. Current practice to identify hazardous asbe...

  19. Prevention of runway incursions due to closed runways or unsuitable runway choices by enhanced crew situational awareness and alerting

    NASA Astrophysics Data System (ADS)

    Vernaleken, Christoph; Urvoy, Carole; Klingauf, Uwe

    2007-04-01

    Of all incidents on the aerodrome surface, Runway Incursions, i.e. the incorrect presence of an aircraft on a runway, are the by far most safety-critical, resulting in many fatalities if they lead to an accident. A lack of flight crew situational awareness is almost always a causal factor in these occurrences, and like any Runway Incursion, the special case of choosing a closed or unsuitable runway - including mistaking a taxiway for a runway - may have catastrophic consequences, as the Singapore Airlines Flight SQ006 accident at Taipei in 2000 and, most recently, Comair Flight 5191, tragically show. In other incidents, such as UPS Flight 896 at Denver in 2001 departing from a closed runway or China Airlines Flight 11 taking off from a taxiway at Anchorage in 2002, a disaster was only avoided by mere luck. This paper describes how the concept for an onboard Surface Movement Awareness and Alerting System (SMAAS) can be applied to this special case and might help to prevent flight crews from taking off or landing on closed runways, unsuitable runways or taxiways, and presents initial evaluation results. An airport moving map based on an ED-99A/DO- 272A compliant Aerodrome Mapping Database (AMDB) is used to visualize runway closures and other applicable airport restrictions, based on NOTAM and D-ATIS data, to provide the crew with enhanced situational awareness in terms of position and operational environment. If this is not sufficient to prevent a hazardous situation, e.g. in case the crew is distracted, a tailored alerting concept consisting of both visual and aural alerts consistent with existing warning systems catches the crew's attention. For runway closures and restrictions, particularly those of temporary nature, the key issue for both extended situational awareness and alerting is how to get the corresponding data to the aircraft's avionics. Therefore, this paper also develops the concept of a machine-readable electronic Pre-flight Information Bulletin (e

  20. Material property assessment and crack identification of recycled concrete with embedded smart cement modules

    NASA Astrophysics Data System (ADS)

    Qiao, Pizhong; Fan, Wei; Chen, Fangliang

    2011-04-01

    In this paper, the material property assessment and crack identification of concrete using embedded smart cement modules are presented. Both the concrete samples with recycled aggregates (RA) and natural aggregates (NA) were prepared. The smart cement modules were fabricated and embedded in concrete beams to serve as either the actuators or sensors, and the elastic wave propagation-based technique was developed to detect the damage (crack) in the recycled aggregate concrete (RAC) beams and monitor the material degradation of RAC beams due to the freeze/thaw (F/T) conditioning cycles. The damage detection results and elastic modulus reduction monitoring data demonstrate that the proposed smart cement modules and associated damage detection and monitoring techniques are capable of identifying crack-type damage and monitoring material degradation of the RAC beams. Both the RAC and natural aggregate concrete (NAC) beams degrade with the increased F/T conditioning cycles. Though the RAC shows a lower reduction percentage of the modulus of elasticity from both the dynamic modulus and wave propagation tests at the given maximum F/T conditioning cycle (i.e., 300 in this study), the RAC tends to degrade faster after the 180 F/T cycles. As observed in this study, the material properties and degradation rate of RAC are comparable to those of NAC, thus making the RAC suitable for transportation construction. The findings in development of damage detection and health monitoring techniques using embedded smart cement modules resulted from this study promote the widespread application of recycled concrete in transportation construction and provide viable and effective health monitoring techniques for concrete structures in general.

  1. Runway Scheduling Using Generalized Dynamic Programming

    NASA Technical Reports Server (NTRS)

    Montoya, Justin; Wood, Zachary; Rathinam, Sivakumar

    2011-01-01

    A generalized dynamic programming method for finding a set of pareto optimal solutions for a runway scheduling problem is introduced. The algorithm generates a set of runway fight sequences that are optimal for both runway throughput and delay. Realistic time-based operational constraints are considered, including miles-in-trail separation, runway crossings, and wake vortex separation. The authors also model divergent runway takeoff operations to allow for reduced wake vortex separation. A modeled Dallas/Fort Worth International airport and three baseline heuristics are used to illustrate preliminary benefits of using the generalized dynamic programming method. Simulated traffic levels ranged from 10 aircraft to 30 aircraft with each test case spanning 15 minutes. The optimal solution shows a 40-70 percent decrease in the expected delay per aircraft over the baseline schedulers. Computational results suggest that the algorithm is promising for real-time application with an average computation time of 4.5 seconds. For even faster computation times, two heuristics are developed. As compared to the optimal, the heuristics are within 5% of the expected delay per aircraft and 1% of the expected number of runway operations per hour ad can be 100x faster.

  2. Microwave processing of cement and concrete materials – towards an industrial reality?

    SciTech Connect

    Buttress, Adam Jones, Aled; Kingman, Sam

    2015-02-15

    Each year a substantial body of literature is published on the use of microwave to process cement and concrete materials. Yet to date, very few if any have lead the realisation of a commercial scale industrial system and is the context under which this review has been undertaken. The state-of the–art is evaluated for opportunities, and the key barriers to the development of new microwave-based processing techniques to enhance production, processing and recycling of cement and concrete materials. Applications reviewed include pyro-processing of cement clinker; accelerated curing, non-destructive testing and evaluation (NDT&E), and end-of-life processing including radionuclide decontamination.

  3. Feasibility of Using Phase Change Materials to Control the Heat of Hydration in Massive Concrete Structures

    PubMed Central

    Choi, Won-Chang; Khil, Bae-Soo; Chae, Young-Seok; Liang, Qi-Bo; Yun, Hyun-Do

    2014-01-01

    This paper presents experimental results that can be applied to select a possible phase change material (PCM), such as a latent heat material (LHM), to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests) were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH)2·8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete. PMID:25133259

  4. Feasibility of using phase change materials to control the heat of hydration in massive concrete structures.

    PubMed

    Choi, Won-Chang; Khil, Bae-Soo; Chae, Young-Seok; Liang, Qi-Bo; Yun, Hyun-Do

    2014-01-01

    This paper presents experimental results that can be applied to select a possible phase change material (PCM), such as a latent heat material (LHM), to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests) were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH)2 · 8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete. PMID:25133259

  5. Studies of ancient concrete as analogs of cementitious sealing materials for a repository in tuff

    SciTech Connect

    Roy, D.M.; Langton, C.A.

    1989-03-01

    The durability of ancient cementitious materials has been investigated to provide data applicable to determining the resistance to weathering of concrete materials for sealing a repository for storage of high-level radioactive waste. Because tuff and volcanic ash are used in the concretes in the vicinity of Rome, the results are especially applicable to a waste repository in tuff. Ancient mortars, plasters, and concretes collected from Rome, Ostia, and Cosa dating to the third century BC show remarkable durability. The aggregates used in the mortars, plasters, and concretes included basic volcanic and pyroclastic rocks (including tuff), terra-cotta, carbonates, sands, and volcanic ash. The matrices of ancient cementitious materials have been characterized and classified into four categories: (1) hydraulic hydrated lime and hydrated lime cements, (2) hydraulic aluminous and ferruginous hydrated lime cements ({plus_minus} siliceous components), (3) pozzolana/hydrated lime cements, and (4) gypsum cements. Most of the materials investigated are in category (3). The materials were characterized to elucidate aspects of the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical, mineralogical, and microstructural factors. Their durability was found to be affected by the matrix mineralogy, particle size, and porosity; aggregate type, grading and proportioning; and the methodology of placement. 30 refs.

  6. Crushed concrete as a phosphate binding material: a potential new management tool.

    PubMed

    Egemose, Sara; Sønderup, Melanie J; Beinthin, Malde V; Reitzel, Kasper; Hoffmann, Carl Christian; Flindt, Mogens R

    2012-01-01

    To avoid eutrophication of receiving waters, effective methods to remove P in urban and agricultural runoff are needed. Crushed concrete may be an effective filter material to remove dissolved and particulate P. Five types of crushed concrete were tested in the laboratory to evaluate the retention capacity of dissolved P. All types removed P very effectively (5.1-19.6 g P kg(-1) concrete), while the possible release of bound P varied between 0.4 and 4.6%. The retention rate was positively related to a decreasing concrete grain size due to an increasing surface area for binding. The P retention was also related to a marked increase in pH (up to pH 12), and the highest retention was observed when pH was high. Under these circumstances, column experiments showed outlet P concentrations <0.0075 mg P L(-1). Furthermore, experiments revealed that release of heavy metals is of no importance for the treated water. We demonstrate that crushed concrete can be an effective tool to remove P in urban and agricultural runoff as filter material in sedimentation/infiltration ponds provided that pH in the treated water is neutralized or the water is diluted before outlet to avoid undesired effects caused by the high pH. PMID:22565246

  7. Balanced improvement of high performance concrete material properties with modified graphite nanomaterials

    NASA Astrophysics Data System (ADS)

    Peyvandi, Amirpasha

    Graphite nanomaterials offer distinct features for effective reinforcement of cementitious matrices in the pre-crack and post-crack ranges of behavior. Thoroughly dispersed and well-bonded nanomaterials provide for effective control of the size and propagation of defects (microcracks) in matrix, and also act as closely spaced barriers against diffusion of moisture and aggressive solutions into concrete. Modified graphite nanomaterials can play multi-faceted roles towards enhancing the mechanical, physical and functional attributes of concrete materials. Graphite nanoplatelets (GP) and carbon nanofibers (CNF) were chosen for use in cementitious materials. Experimental results highlighted the balanced gains in diverse engineering properties of high-performance concrete realized by introduction of graphite nanomaterials. Nuclear Magnetic Resonance (NMR) spectroscopy was used in order to gain further insight into the effects of nanomaterials on the hydration process and structure of cement hydrates. NMR exploits the magnetic properties of certain atomic nuclei, and the sensitivity of these properties to local environments to generate data which enables determination of the internal structure, reaction state, and chemical environment of molecules and bulk materials. 27 Al and 29Si NMR spectroscopy techniques were employed in order to evaluate the effects of graphite nanoplatelets on the structure of cement hydrates, and their resistance to alkali-silica reaction (ASR), chloride ion diffusion, and sulfate attack. Results of 29Si NMR spectroscopy indicated that the percent condensation of C-S-H in cementitious paste was lowered in the presence of nanoplatelets at the same age. The extent of chloride diffusion was assessed indirectly by detecting Friedel's salt as a reaction product of chloride ions with aluminum-bearing cement hydrates. Graphite nanoplatelets were found to significantly reduce the concentration of Friedel's salt at different depths after various periods

  8. Runway hazard detection in poor visibility conditions

    NASA Astrophysics Data System (ADS)

    Jiang, Bo; Rahman, Zia-ur

    2012-01-01

    More recently, research on enhancing the situational awareness of pilots, especially in poor visibility flight conditions, gains more and more interests. Since pilots may not be able to spot the runway clearly in poor visibility conditions, such as fog, smoke, haze or dim lighting conditions, aviation landing problem can occur due to the (unexpected) presence of objects on the runway. Complicated and trivial instruments, switches, bottoms, plus sudden happenings are enough for the pilots to take care of during landing approach. Therefore, an automatic hazard detection approach that combines non-linear Multi-scale Retinex (MSR) image enhancement, edge detection with basic edge pattern analysis, and image analysis is investigated. The effect of applying the enhancement method is to make the image of the runway almost independent from the poor atmospheric conditions. The following smart edge detection process extracts edge information, which can also reduce the storing space, the comparison and retrieval time, and the effect of sensor noise. After analyzing the features existing in the edge differences occurring in the runway area by digital image processing techniques, the existing potential hazard will be localized and labeled. Experimental results show that the proposed approach is effective in runway hazard detection in poor visibility conditions.

  9. Runway Incursion Prevention: A Technology Solution

    NASA Technical Reports Server (NTRS)

    Young, Steven D.; Jones, Denise R.

    2001-01-01

    A runway incursion occurs any time an airplane, vehicle, person or object on the ground creates a collision hazard with an airplane that is taking off or landing at an airport under the supervision of Air Traffic Control (ATC). Despite the best efforts of the Federal Aviation Administration (FAA), runway incursions continue to occur more frequently. The number of incursions reported in the U.S. rose from 186 in 1993 to 431 in 2000, an increase of 132 percent. Recently, the National Transportation Safety Board (NTSB) has made specific recommendations for reducing runway incursions including a recommendation that the FAA require, at all airports with scheduled passenger service, a ground movement safety system that will prevent runway incursions; the system should provide a direct warning capability to flight crews. To this end, NASA and its industry partners have developed an advanced surface movement guidance and control system (A-SMGCS) architecture and operational concept that are designed to prevent runway incursions while also improving operational capability. This operational concept and system design have been tested in both full-mission simulation and operational flight test experiments at major airport facilities. Anecdotal, qualitative, and specific quantitative results will be presented along with an assessment of technology readiness with respect to equipage.

  10. Terminal Area Procedures for Paired Runways

    NASA Technical Reports Server (NTRS)

    Lozito, Sandy

    2011-01-01

    Parallel Runway operations have been found to increase capacity within the National Airspace (NAS) however, poor visibility conditions reduce this capacity [1]. Much research has been conducted to examine the concepts and procedures related to parallel runways however, there has been no investigation of the procedures associated with the strategic and tactical pairing of aircraft for these operations. This study developed and examined the pilot and controller procedures and information requirements for creating aircraft pairs for parallel runway operations. The goal was to achieve aircraft pairing with a temporal separation of 15s(+/- 10s error) at a coupling point that is about 12 nmi from the runway threshold. Two variables were explored for the pilot participants: Two levels of flight deck automation (current-day flight deck automation, and a prototype future automation) as well as two flight deck displays that assisted in pilot conformance monitoring. The controllers were also provided with automation to help create and maintain aircraft pairs. Data showed that the operations in this study were found to be acceptable and safe. Workload when using the pairing procedures and tools was generally low for both controllers and pilots, and situation awareness (SA) was typically moderate to high. There were some differences based upon the display and automation conditions for the pilots. Future research should consider the refinement of the concepts and tools for pilot and controller displays and automation for parallel runway concepts.

  11. Runway Incursion Prevention System Simulation Evaluation

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.

    2002-01-01

    A Runway Incursion Prevention System (RIPS) was evaluated in a full mission simulation study at the NASA Langley Research center in March 2002. RIPS integrates airborne and ground-based technologies to provide (1) enhanced surface situational awareness to avoid blunders and (2) alerts of runway conflicts in order to prevent runway incidents while also improving operational capability. A series of test runs was conducted in a high fidelity simulator. The purpose of the study was to evaluate the RIPS airborne incursion detection algorithms and associated alerting and airport surface display concepts. Eight commercial airline crews participated as test subjects completing 467 test runs. This paper gives an overview of the RIPS, simulation study, and test results.

  12. Diffusion of Iodine and Rhenium in Category 3 Waste Encasement Concrete and Soil Fill Material

    SciTech Connect

    Wellman, Dawn M.; Mattigod, Shas V.; Whyatt, Greg A.; Powers, Laura; Parker, Kent E.; Wood, Marcus I.

    2006-12-15

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e. sorption or precipitation). This understanding will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. A set of diffusion experiments using carbonated and non-carbonated concrete-soil half cells was conducted under unsaturated conditions (4% and 7% by wt moisture content). Spiked concrete half-cell specimens were prepared with and without colloidal metallic iron addition and were carbonated using supercritical carbon dioxide. Spikes of I and Re were added to achieve measurable diffusion profile in the soil part of the half-cell. In addition, properties of concrete materials likely to influence radionuclide migration such as carbonation were evaluated in an effort to correlate these properties with the release of iodine and rhenium.

  13. 1. VIEW OF ALTERNATE RUNWAY (TAXIWAY J) LOOKING NORTHWEST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF ALTERNATE RUNWAY (TAXIWAY J) LOOKING NORTHWEST FROM SOUTH RUNWAY OBSERVATION BUILDING TOWARD BUILDING 8250 (ARCH HANGAR) AND FLIGHTLINE BUILDINGS. - Loring Air Force Base, Airfield, Central portion of base, Limestone, Aroostook County, ME

  14. NASA tire/runway friction projects

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1995-01-01

    The paper reviews several aspects of NASA Langley Research Center's tire/runway friction evaluations directed towards improving the safety and economy of aircraft ground operations. The facilities and test equipment used in implementing different aircraft tire friction studies and other related aircraft ground performance investigations are described together with recent workshop activities at NASA Wallops Flight Facility. An overview of the pending Joint NASA/Transport Canada/FM Winter Runway Friction Program is given. Other NASA ongoing studies and on-site field tests are discussed including tire wear performance and new surface treatments. The paper concludes with a description of future research plans.

  15. Probabilistic computer model of optimal runway turnoffs

    NASA Technical Reports Server (NTRS)

    Schoen, M. L.; Preston, O. W.; Summers, L. G.; Nelson, B. A.; Vanderlinden, L.; Mcreynolds, M. C.

    1985-01-01

    Landing delays are currently a problem at major air carrier airports and many forecasters agree that airport congestion will get worse by the end of the century. It is anticipated that some types of delays can be reduced by an efficient optimal runway exist system allowing increased approach volumes necessary at congested airports. A computerized Probabilistic Runway Turnoff Model which locates exits and defines path geometry for a selected maximum occupancy time appropriate for each TERPS aircraft category is defined. The model includes an algorithm for lateral ride comfort limits.

  16. Concrete crushing and sampling, a methodology and technology for the unconditional release of concrete material from decommissioning

    SciTech Connect

    Gills, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R.

    2007-07-01

    Belgoprocess started the industrial decommissioning of the main process building of the former Eurochemic reprocessing plant in 1990, after completion of a pilot project. Two small storage buildings for final products from reprocessing were dismantled to verify the assumptions made in a previous paper study on decommissioning, to demonstrate and develop dismantling techniques and to train personnel. Both buildings were emptied and decontaminated to background levels. They were demolished and the remaining concrete debris was disposed of as industrial waste and green field conditions restored. Currently, the decommissioning operations carried out at the main building have made substantial progress. They are executed on an industrial scale. In view of the final demolition of the building, foreseen to start in the middle of 2008, a clearance methodology for the concrete from the cells into the Eurochemic building has been developed. It considers at least one complete measurement of all concrete structures and the removal of all detected residual radionuclides. This monitoring sequence is followed by a controlled demolition of the concrete structures and crushing of the resulting concrete parts to smaller particles. During the crushing operations, metal parts are separated from the concrete and representative concrete samples are taken. The frequency of sampling meets the prevailing standards. In a further step, the concrete samples are milled, homogenised, and a smaller fraction is sent to the laboratory for analyses. The paper describes the developed concrete crushing and sampling methodology. (authors)

  17. Development of construction materials like concrete from lunar soils without water

    NASA Technical Reports Server (NTRS)

    Desai, Chandra S.; Saadatmanesh, H.; Frantziskonis, G.

    1989-01-01

    The development of construction materials such as concrete from lunar soils without the use of water requires a different methodology than that used for conventional terrestrial concrete. A unique approach is attempted that utilizes factors such as initial vacuum and then cyclic loading to enhance the mechanical properties of dry materials similar to those available on the moon. The application of such factors is expected to allow reorientation, and coming together, of particles of the materials toward the maximum theoretical density. If such a density can provide deformation and strength properties for even a limited type of construction, the approach can have significant application potential, although other factors such as heat and chemicals may be needed for specific construction objectives.

  18. Evaluation of near surface material degradation in concrete using nonlinear Rayleigh surface waves

    NASA Astrophysics Data System (ADS)

    Gross, J.; Kim, J.-Y.; Jacobs, L. J.; Kurtis, K. E.; Qu, J.

    2013-01-01

    Comparative studies of nondestructive evaluation methods have shown that nonlinear ultrasonic techniques are more sensitive than conventional linear methods to changes in material microstructure and the associated small-scale damage. Many of the material degradation processes such as carbonation in concrete, corrosion in metals, etc., initiate at the surface. In such cases, ultrasonic Rayleigh surface waves are especially appropriate for detection and characterization of damage since their energy is concentrated in the top layer of the test object. For the civil engineering infrastructure, only a limited number of field applicable nonlinear ultrasonic techniques have been introduced. In this paper a nonlinear ultrasonic measurement technique based on the use of Rayleigh waves is developed and used to characterize carbonation in concrete samples. This work develops a collinear mixing technique for concrete structures. Wedge transducer is used for the generation and an accelerometer for the detection of the fundamental and nonlinearity modulated ultrasonic signal components. The measurements are made by varying the input voltage and along the propagation distance. The slope of the normalized modulation amplitudes is taken as the nonlinearity parameter. Concrete samples with two different levels of damage are examined, and the difference of the two fundamental frequencies is used to quantify damage state.

  19. Health monitoring and rehabilitation of a concrete structure using intelligent materials

    NASA Astrophysics Data System (ADS)

    Song, G.; Mo, Y. L.; Otero, K.; Gu, H.

    2006-04-01

    This paper presents the concept of an intelligent reinforced concrete structure (IRCS) and its application in structural health monitoring and rehabilitation. The IRCS has multiple functions which include self-rehabilitation, self-vibration damping, and self-structural health monitoring. These functions are enabled by two types of intelligent (smart) materials: shape memory alloys (SMAs) and piezoceramics. In this research, Nitinol type SMA and PZT (lead zirconate titanate) type piezoceramics are used. The proposed concrete structure is reinforced by martensite Nitinol cables using the method of post-tensioning. The martensite SMA significantly increases the concrete's damping property and its ability to handle large impact. In the presence of cracks due to explosions or earthquakes, by electrically heating the SMA cables, the SMA cables contract and close up the cracks. In this research, PZT patches are embedded in the concrete structure to detect possible cracks inside the concrete structure. The wavelet packet analysis method is then applied as a signal-processing tool to analyze the sensor signals. A damage index is defined to describe the damage severity for health monitoring purposes. In addition, by monitoring the electric resistance change of the SMA cables, the crack width can be estimated. To demonstrate this concept, a concrete beam specimen with reinforced SMA cables and with embedded PZT patches is fabricated. Experiments demonstrate that the IRC has the ability of self-sensing and self-rehabilitation. Three-point bending tests were conducted. During the loading process, a crack opens up to 0.47 inches. Upon removal of the load and heating the SMA cables, the crack closes up. The damage index formed by wavelet packet analysis of the PZT sensor data predicts and confirms the onset and severity of the crack during the loading. Also during the loading, the electrical resistance value of the SMA cable changes by up to 27% and this phenomenon is used to

  20. Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

    NASA Technical Reports Server (NTRS)

    Byrdsong, T. A.

    1973-01-01

    An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

  1. Evaluation of Scheduling Methods for Multiple Runways

    NASA Technical Reports Server (NTRS)

    Bolender, Michael A.; Slater, G. L.

    1996-01-01

    Several scheduling strategies are analyzed in order to determine the most efficient means of scheduling aircraft when multiple runways are operational and the airport is operating at different utilization rates. The study compares simulation data for two and three runway scenarios to results from queuing theory for an M/D/n queue. The direction taken, however, is not to do a steady-state, or equilibrium, analysis since this is not the case during a rush period at a typical airport. Instead, a transient analysis of the delay per aircraft is performed. It is shown that the scheduling strategy that reduces the delay depends upon the density of the arrival traffic. For light traffic, scheduling aircraft to their preferred runways is sufficient; however, as the arrival rate increases, it becomes more important to separate traffic by weight class. Significant delay reduction is realized when aircraft that belong to the heavy and small weight classes are sent to separate runways with large aircraft put into the 'best' landing slot.

  2. Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1990-01-01

    Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

  3. Perseus B Landing on Runway

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Perseus B high-altitude, remotely piloted research vehicle touches down on the runway at Edwards AFB, adjacent to NASA's Dryden Flight Research Center, after a test flight in September 1999. The Perseus B was the third version of the Perseus design developed by Aurora Flight Sciences under the Dryden-managed Environmental Research Aircraft and Sensor Technology (ERAST) program. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third

  4. Runway Operations Planning: A Two-Stage Solution Methodology

    NASA Technical Reports Server (NTRS)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. Thus, Runway Operations Planning (ROP) is a critical component of airport operations planning in general and surface operations planning in particular. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, may be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. Generating optimal runway operations plans was approached in with a 'one-stage' optimization routine that considered all the desired objectives and constraints, and the characteristics of each aircraft (weight class, destination, Air Traffic Control (ATC) constraints) at the same time. Since, however, at any given point in time, there is less uncertainty in the predicted demand for departure resources in terms of weight class than in terms of specific aircraft, the ROP problem can be parsed into two stages. In the context of the Departure Planner (OP) research project, this paper introduces Runway Operations Planning (ROP) as part of the wider Surface Operations Optimization (SOO) and describes a proposed 'two stage' heuristic algorithm for solving the Runway Operations Planning (ROP) problem. Focus is specifically given on including runway crossings in the planning process of runway operations. In the first stage, sequences of departure class slots and runwy crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the

  5. High-strength fibrous concrete of Russian Far East natural materials

    NASA Astrophysics Data System (ADS)

    Fediuk, R.

    2016-02-01

    Fiber-reinforced concrete is designed on composite binder. At 1.6% of reinforcing steel anchoring fiber maximum physical and mechanical properties (Rcompr = 100.9 MPa) can be obtained. It was found that the combined effect of mechanical and chemical activation (the presence of limestone particles) increases the pozzolanic activity of acidic ashes. It has a catalytic effect on the reaction activity of the surface of ash and sand during machining in vario-planetary mill. Furthermore, the addition of limestone increases the alkalinity of the concrete, which leads to the formation of greater hydration products of cement per unit of time. Theoretical and experimental results can be recommended for expanded implementation of the construction in various regions of the Russian Federation, taking into account the availability of raw materials.

  6. Flexural behavior of reinforced concrete beams strengthened with advanced composite materials

    SciTech Connect

    Shahawy, M.A.; Beitelman, T.

    1996-12-31

    This paper presents the results of a feasibility study to investigate the flexural behavior of structurally damaged reinforced and prestressed concrete members retrofitted with bonded carbon fiber materials. The effect of CFRP laminates, bonded to the soffit of precracked reinforced concrete rectangular and tee beams, is investigated in terms of flexural strength, deflections, cracking behavior and failure modes. The results indicate that strengthening of significantly cracked structural members by bonding Carbon laminates is structurally efficient and that the retrofitted members are restored to stiffness and strength values nearly equal to or greater than those of the original. The results indicate that the retrofitted members maintained adequate structural integrity and composite action at all stages of testing up to failure.

  7. Optimum runway orientation relative to crosswinds

    NASA Technical Reports Server (NTRS)

    Falls, L. W.; Brown, S. C.

    1972-01-01

    Specific magnitudes of crosswinds may exist that could be constraints to the success of an aircraft mission such as the landing of the proposed space shuttle. A method is required to determine the orientation or azimuth of the proposed runway which will minimize the probability of certain critical crosswinds. Two procedures for obtaining the optimum runway orientation relative to minimizing a specified crosswind speed are described and illustrated with examples. The empirical procedure requires only hand calculations on an ordinary wind rose. The theoretical method utilizes wind statistics computed after the bivariate normal elliptical distribution is applied to a data sample of component winds. This method requires only the assumption that the wind components are bivariate normally distributed. This assumption seems to be reasonable. Studies are currently in progress for testing wind components for bivariate normality for various stations. The close agreement between the theoretical and empirical results for the example chosen substantiates the bivariate normal assumption.

  8. Runway Operations Planning: A Two-Stage Heuristic Algorithm

    NASA Technical Reports Server (NTRS)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, can also be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. This paper introduces a two stage heuristic algorithm for solving the Runway Operations Planning (ROP) problem. In the first stage, sequences of departure class slots and runway crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the departure class slots are populated with specific flights from the pool of available aircraft, by solving an integer program with a Branch & Bound algorithm implementation. Preliminary results from this implementation of the two-stage algorithm on real-world traffic data are presented.

  9. Reliable classification of moving waste materials with LIBS in concrete recycling.

    PubMed

    Xia, Han; Bakker, M C M

    2014-03-01

    Effective discrimination between different waste materials is of paramount importance for inline quality inspection of recycle concrete aggregates from demolished buildings. The moving targeted materials in the concrete waste stream are wood, PVC, gypsum block, glass, brick, steel rebar, aggregate and cement paste. For each material, up to three different types were considered, while thirty particles of each material were selected. Proposed is a reliable classification methodology based on integration of the LIBS spectral emissions in a fixed time window, starting from the deployment of the laser shot. PLS-DA (multi class) and the hybrid combination PCA-Adaboost (binary class) were investigated as efficient classifiers. In addition, mean centre and auto scaling approaches were compared for both classifiers. Using 72 training spectra and 18 test spectra per material, each averaged by ten shots, only PLS-DA achieved full discrimination, and the mean centre approach made it slightly more robust. Continuing with PLS-DA, the relation between data averaging and convergence to 0.3% average error was investigated using 9-fold cross-validations. Single-shot PLS-DA presented the highest challenge and most desirable methodology, which converged with 59 PC. The degree of success in practical testing will depend on the quality of the training set and the implications of the possibly remaining false positives. PMID:24468365

  10. REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

    SciTech Connect

    XU, X. George; Zhang, X.C.

    2002-05-10

    Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. To improve current practice in identifying hazardous materials and in characterizing radioactive contamination, an interdisciplinary team from Rensselaer has conducted research in two aspects: (1) to develop terahertz time-domain spectroscopy and imaging system that can be used to analyze environmental samples such as asbestos in the field, and (2) to develop algorithms for characterizing the radioactive contamination depth profiles in real-time in the field using gamma spectroscopy. The basic research focused on the following: (1) mechanism of generating of broadband pulsed radiation in terahertz region, (2) optimal free-space electro-optic sampling for asbestos, (3) absorption and transmission mechanisms of asbestos in THz region, (4) the role of asbestos sample conditions on the temporal and spectral distributions, (5) real-time identification and mapping of asbestos using THz imaging, (7) Monte Carlo modeling of distributed contamination from diffusion of radioactive materials into porous concrete and asbestos materials, (8) development of unfolding algorithms for gamma spectroscopy, and (9) portable and integrated spectroscopy systems for field testing in DOE. Final results of the project show that the combination of these innovative approaches has the potential to bring significant improvement in future risk reduction and cost/time saving in DOE's D and D activities.

  11. Formal Verification of the Runway Safety Monitor

    NASA Technical Reports Server (NTRS)

    Siminiceanu, Radu; Ciardo, Gianfranco

    2006-01-01

    The Runway Safety Monitor (RSM) designed by Lockheed Martin is part of NASA's effort to reduce runway accidents. We developed a Petri net model of the RSM protocol and used the model checking functions of our tool SMART to investigate a number of safety properties in RSM. To mitigate the impact of state-space explosion, we built a highly discretized model of the system, obtained by partitioning the monitored runway zone into a grid of smaller volumes and by considering scenarios involving only two aircraft. The model also assumes that there are no communication failures, such as bad input from radar or lack of incoming data, thus it relies on a consistent view of reality by all participants. In spite of these simplifications, we were able to expose potential problems in the RSM conceptual design. Our findings were forwarded to the design engineers, who undertook corrective action. Additionally, the results stress the efficiency attained by the new model checking algorithms implemented in SMART, and demonstrate their applicability to real-world systems.

  12. Non-linear finite element-based material constitutive law for zero slump steel fiber reinforced concrete pipe structures

    NASA Astrophysics Data System (ADS)

    Mikhaylova, Alena

    This study presents a comprehensive investigation of performance and behavior of steel-fiber reinforced concrete pipes (SFRCP). The main goal of this study is to develop the material constitutive model for steel fiber reinforced concrete used in dry-cast application. To accomplish this goal a range of pipe sizes varying from 15 in. (400 mm) to 48 in. (1200 mm) in diameter and fiber content of 0.17%, 0.25%, 0.33%, 0.5%, 0.67% and 83% by volume were produced. The pipes were tested in three-edge bearing condition to obtain the load-deformation response and overall performance of the pipe. The pipes were also subjected to hydrostatic joint and joint shear tests to evaluate the performance of the fiber-pipe joints for water tightness and under differential displacements, respectively. In addition, testing on hardened concrete was performed to obtain the basic mechanical material properties. High variation in the test results for material testing was identified as a part of experimental investigation. A three-dimensional non-linear finite element model of the pipe under the three edge bearing condition was developed to identify the constitutive material relations of fiber-concrete composite. A constitutive model of concrete implementing the concrete plasticity and continuum fracture mechanics was considered for defining the complex non-linear behavior of fiber-concrete. Three main concrete damage algorithms were examined: concrete brittle cracking, concrete damaged plasticity with adaptive meshing technique and concrete damaged plasticity with visco-plastic regularization. The latter was identified as the most robust and efficient to model the post-cracking behavior of fiber reinforced concrete and was used in the subsequent studies. The tension stiffening material constitutive law for composite concrete was determined by converging the FEM solution of load-deformation response with the results of experimental testing. This was achieved by iteratively modifying the non

  13. Comparison of performance of partial prestressed beam-column subassemblages made of reactive powder concrete and normal concrete materials using finite element models

    NASA Astrophysics Data System (ADS)

    Nurjannah, S. A.; Budiono, B.; Imran, I.; Sugiri, S.

    2016-04-01

    Research on concrete material continues in several countries and had produced a concrete type of Ultra High Performance Concrete (UHPC) which has a better compressive strength, tensile strength, flexural strength, modulus of elasticity, and durability than normal concrete (NC) namely Reactive Powder Concrete (RPC). Researches on structures using RPC material showed that the RPC structures had a better performance than the NC structures in resisting gravity and lateral cyclic loads. In this study, an experiment was conducted to apply combination of constant axial and lateral cyclic loads to a prototype of RPC interior partial prestressed beam-column subassemblage (prototype of BCS-RPC) with a value of Partial Prestressed Ratio (PPR) of 31.72% on the beam. The test results were compared with finite element model of beam-column subassemblage made of RPC by PPR of 31.72% (BCS-RPC-31.72). Furthermore, there was BCS-RPC modeling with PPR of 21.39% (BCS-RPC-21.39) and beam-column subassemblages made of NC materials modeling with a value of PPR at 21.09% (BCS-NC-21.09) and 32.02% (BCS-NC-32.02). The purpose of this study was to determine the performance of the BCS-RPC models compared to the performance of the BCS-NC models with PPR values below and above 25%, which is the maximum limit of permitted PPR. The results showed that all models of BCS-RPC had a better performance than all models of BCS-NC and the BCS-RPC model with PPR above 25% still behaved ductile and was able to dissipate energy well.

  14. Novel selective dyeing method for chrysotile asbestos detection in concrete materials.

    PubMed

    Oke, Yoshihiko; Yamasaki, Nakamichi; Amamoto, Go Y; Sasaki, Kazuhiro; Maeta, Naomi; Fujimaki, Hirokazu; Hashida, Toshiyuki

    2008-03-01

    There are a tremendous number of asbestos-containing buildings without any surveys on the presence of asbestos because of the difficulty to detect asbestos in building materials simply and quickly, although a great deal of worldwide effort was put into removing asbestos of which inhalation causes serious diseases. In this study, we newly developed a simple dyeing method to detect chrysotile asbestos, the most commonly used type of asbestos, in asbestos-cement composite materials using magnesium-chelating organic dyes. As an essential process for selective dyeing of chrysotile asbestos, special pretreatment with a calcium-chelating agent was developed to prevent the dyes from reacting with calcium, which is the major component of concrete materials. Our developed selective dyeing method was shown to possess sufficient sensitivity for detecting chrysotile asbestos in an amount greater than 0.1 mass% in concrete specimens, and there was an approximately linear relationship between the area fraction of dyed spots and the mass fraction of chrysotile asbestos. Our results may provide a basis for further development of a simple on-site detection method for chrysotile asbestos in building materials and may facilitate the progress of control and removal of asbestos in the environment. PMID:18441814

  15. Discrimination of high-Z materials in concrete-filled containers using muon scattering tomography

    NASA Astrophysics Data System (ADS)

    Frazão, L.; Velthuis, J.; Thomay, C.; Steer, C.

    2016-07-01

    An analysis method of identifying materials using muon scattering tomography is presented, which uses previous knowledge of the position of high-Z objects inside a container and distinguishes them from similar materials. In particular, simulations were performed in order to distinguish a block of Uranium from blocks of Lead and Tungsten of the same size, inside a concrete-filled drum. The results show that, knowing the shape and position from previous analysis, it is possible to distinguish 5 × 5 × 5 cm3 blocks of these materials with about 4h of muon exposure, down to 2 × 2 × 2 cm3 blocks with 70h of data using multivariate analysis (MVA). MVA uses several variables, but it does not benefit the discrimination over a simpler method using only the scatter angles. This indicates that the majority of discrimination is provided by the angular information. Momentum information is shown to provide no benefits in material discrimination.

  16. Cockpit Technology for Prevention of General Aviation Runway Incursions

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Jones, Denise R.

    2007-01-01

    General aviation accounted for 74 percent of runway incursions but only 57 percent of the operations during the four-year period from fiscal year (FY) 2001 through FY2004. Elements of the NASA Runway Incursion Prevention System were adapted and tested for general aviation aircraft. Sixteen General Aviation pilots, of varying levels of certification and amount of experience, participated in a piloted simulation study to evaluate the system for prevention of general aviation runway incursions compared to existing moving map displays. Pilots flew numerous complex, high workload approaches under varying weather and visibility conditions. A rare-event runway incursion scenario was presented, unbeknownst to the pilots, which represented a typical runway incursion situation. The results validated the efficacy and safety need for a runway incursion prevention system for general aviation aircraft.

  17. Lunar concrete: Prospects and challenges

    NASA Astrophysics Data System (ADS)

    Khitab, Anwar; Anwar, Waqas; Mehmood, Imran; Kazmi, Syed Minhaj Saleem; Munir, Muhammad Junaid

    2016-02-01

    The possibility of using concrete as a construction material at the Moon surface is considered. Dissimilarities between the Earth and the Moon and their possible effects on concrete are also emphasized. Availability of constituent materials for concrete at lunar surface is addressed. An emphasis is given to two types of materials, namely, hydraulic concrete and sulfur concrete. Hydraulic concrete necessitates the use of water and sulfur concrete makes use of molten sulfur in lieu of cement and water.

  18. Polymer concrete patching manual

    NASA Astrophysics Data System (ADS)

    Fontana, J. J.; Bartholomew, J.

    1982-06-01

    The practicality of using polymer concrete to repair deteriorated portland cement concrete bridge decks and pavements was demonstrated. This manual outlines the procedures for using polymer concrete as a rapid patching material to repair deteriorated concrete. The process technology, materials, equipment, and safety provisions used in manufacturing and placing polymer concrete are discussed. Potential users are informed of the various steps necessary to insure successful field applications of the material.

  19. Real-Time Identification and Characterization of Asbestos and Concrete Materials with Radioactive Contamination

    SciTech Connect

    Xu, George; Zhang, Xi-Cheng

    1999-06-01

    Concrete and asbestos-containing materials were widely used in U.S. Department of Energy (DOE) building construction in the 1940s and 1950s. Over the years, many of these porous building materials have been contaminated with radioactive sources, on and below the surface. This intractable radioactive-and-hazardous- asbestos mixed-waste-stream has created a tremendous challenge to DOE decontamination and decommissioning (D&D) project managers. The current practice to identify asbestos and to characterize radioactive contamination depth profiles involve bore sampling, and is inefficient, costly, and unsafe. A three-year research project was started on 10/1/98 at Rensselaer with the following ultimate goals: (1) development of novel non-destructive methods for identifying the hazardous asbestos in real-time and in-situ, and (2) development of new algorithms and apparatus for characterizing the radioactive contamination depth profile in real-time and in-situ.

  20. Real-Time Identification and Characterization of Asbestos and Concrete Materials with Radioactive Contamination

    SciTech Connect

    Xu, George; Zhang, Xi-Cheng

    2000-06-01

    Concrete and asbestos-containing materials were widely used in U.S. Department of Energy (DOE) building construction in the 1940s and 1950s. Over the years, many of these porous building materials have been contaminated with radioactive sources, on and below the surface. This intractable radioactive-and-hazardous-asbestos mixed-waste stream has created a tremendous challenge to DOE decontamination and decommissioning (D&D) project managers. The current practice to identify asbestos and to characterize radioactive contamination depth profiles in based solely on bore sampling, which is inefficient, costly, and unsafe. A three-year research project was started 1998 at Rensselaer with the following ultimate goals: (1) development of novel non-destructive methods for identifying the hazardous asbestos in real-time and in-situ, and (2) development of new algorithms and apparatus for characterizing the radioactive contamination depth profile in real-time and in-situ.

  1. Nuclear Technology. Course 29: Civil/Structural Inspection. Module 29-6, Pre-Stressed Concrete Materials, Fabrication and Inspection.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This sixth in a series of six modules for a course titled Civil/Structural Inspection describes inspection activities associated with pre-stressed concrete such as reviewing material certifications and test reports, inspecting construction operations, performing materials testing, and preparing records and reports of inspection and testing…

  2. 14 CFR 151.9 - Runway clear zones: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Runway clear zones: General. 151.9 Section 151.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... above the elevation of the runway or 50 feet above the terrain at the outer extremity of the clear...

  3. 14 CFR 151.9 - Runway clear zones: General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Runway clear zones: General. 151.9 Section 151.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... above the elevation of the runway or 50 feet above the terrain at the outer extremity of the clear...

  4. 14 CFR 151.9 - Runway clear zones: General.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Runway clear zones: General. 151.9 Section 151.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... above the elevation of the runway or 50 feet above the terrain at the outer extremity of the clear...

  5. 14 CFR 151.9 - Runway clear zones: General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Runway clear zones: General. 151.9 Section 151.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... above the elevation of the runway or 50 feet above the terrain at the outer extremity of the clear...

  6. 14 CFR 151.9 - Runway clear zones: General.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Runway clear zones: General. 151.9 Section 151.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... above the elevation of the runway or 50 feet above the terrain at the outer extremity of the clear...

  7. 14 CFR 151.77 - Runway paving: General rules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... project include pavement construction and reconstruction, and include runway grooving to improve skid... course to correct major irregularities in the pavement. Runway resealing or refilling joints as an... Specification P-609) on a pavement the current surface of which consists of that kind of a bituminous...

  8. 32 CFR 256.6 - Runway classification by aircraft type.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Runway classification by aircraft type. 256.6 Section 256.6 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS AIR INSTALLATIONS COMPATIBLE USE ZONES § 256.6 Runway classification by...

  9. 14 CFR 151.77 - Runway paving: General rules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Runway paving: General rules. 151.77 Section 151.77 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.77 Runway paving:...

  10. 14 CFR 151.77 - Runway paving: General rules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.77 Runway paving: General... treatment. (c) On new pavement construction, the applying of a bituminous seal coat on plant hot-mix... entire runway may be sealed. (e) Appendix C to this part sets forth typical eligible and ineligible...

  11. 14 CFR 151.77 - Runway paving: General rules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.77 Runway paving: General... treatment. (c) On new pavement construction, the applying of a bituminous seal coat on plant hot-mix... entire runway may be sealed. (e) Appendix C to this part sets forth typical eligible and ineligible...

  12. 14 CFR 151.77 - Runway paving: General rules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Runway paving: General rules. 151.77 Section 151.77 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.77 Runway paving: General rules. (a) On any airport, paving of...

  13. View from the center of the 1922 Seaplane Runway, with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from the center of the 1922 Seaplane Runway, with the 1930s Seaplane Beach angling off to the right - U.S. Naval Base, Pearl Harbor, Seaplane Runway, Southern tip of Ford Island, near Lexington Boulevard, Pearl City, Honolulu County, HI

  14. Improving the damping ability by the addition of Nano SiO2 to the concrete materials

    NASA Astrophysics Data System (ADS)

    Zou, Dujian; Liu, Tiejun; Teng, Jun

    2009-07-01

    Damping in structures is commonly provided by viscoelastic nonstructural materials. Due to the large volume of structural materials in a structure, the contribution of a structural material to damping can be substantial. In this paper, the experimental investigation on damping ability of concrete materials and its members with Nana SiO2 was carried out by the method of 3-point bending beam damping measurement and cantilever beam free vibration respectively. The microstructure of concrete mix with Nano SiO2 was observed by XRD and SEM, then damping mechanism was discussed. The experimental results show that the damping reinforced effect achieved best with the 4% mixture ratio of Nana SiO2, but the optimal adulteration quantity of Nano SiO2 was 3% of cement weight by the comprehensive consideration of cost, workability, strength and dynamic properties. Nano materials as a mixture increase interfaces, and the non-uniform stress distribution under external force improves frictional damping energy consumption ability of concrete. The experimental results on the damping ratio and the loss tangent of the concrete materials with Nano materials are consistent.

  15. Performance based seismic qualification of reinforced concrete nuclear materials processing facilities

    SciTech Connect

    Mertz, G.E.; Loceff, F.; Houston, T.; Rauls, G.; Mulliken, J.

    1997-09-01

    A seismic qualification of a reinforced concrete nuclear materials processing facility using performance based acceptance criteria is presented. Performance goals are defined in terms of a minimum annual seismic failure frequency. Pushover analyses are used to determine the building`s ultimate capacity and relate the capacity to roof drift and joint rotation. Nonlinear dynamic analyses are used to quantify the building`s drift using a suite of ground motion intensities representing varying soil conditions and levels of seismic hazard. A correlation between joint rotation and building drift to damage state is developed from experimental data. The damage state and seismic hazard are convolved to determine annual seismic failure frequency. The results of this rigorous approach is compared to those using equivalent force methods and pushover techniques recommended by ATC-19 and FEMA-273.

  16. Development of polymer concrete for dike insulation at LNG facilities: Phase 4, Low cost materials

    SciTech Connect

    Kukacka, L.E.

    1991-01-01

    Earlier GRI-sponsored work at Brookhaven National Laboratory has resulted in the development and utilization of insulating polymer concrete composites (IPC) as a means of reducing the evaporation rate of liquified natural gas in the event of a spill into a containment dike, thereby improving the safety at these sites. Although all of the required properties can be attained with the IPC, it was estimated that a low-cost replacement for the expensive organic binder would be necessary before use of the material would be cost-effective. In the current program, several latex modified cement formulations were evaluated and the most promising one identified. A mixture of two carboxylated styrene-butadiene latexes was selected for use in detailed laboratory property characterizations and a subsequent field evaluation. When compared to the properties of IPC, the latex-modified insulating materials display somewhat higher thermal conductivities, greater permeability to water, and reduced strength. However, these properties still meet most of the performance criteria, and the unit cost of the material is less than one-fifth that of IPC made with epoxy binders. When installed as a 0.75-in. thick overlay, material costs are estimated to be $1.00/ft{sup 2}.

  17. Nano-modified cement composites and its applicability as concrete repair material

    NASA Astrophysics Data System (ADS)

    Manzur, Tanvir

    Nanotechnology or Nano-science, considered the forth industrial revolution, has received considerable attention in the past decade. The physical properties of a nano-scaled material are entirely different than that of bulk materials. With the emerging nanotechnology, one can build material block atom by atom. Therefore, through nanotechnology it is possible to enhance and control the physical properties of materials to a great extent. Composites such as concrete materials have very high strength and Young's modulus but relatively low toughness and ductility due to their covalent bonding between atoms and lacking of slip systems in the crystal structures. However, the strength and life of concrete structures are determined by the microstructure and mass transfer at nano scale. Cementitious composites are amenable to manipulation through nanotechnology due to the physical behavior and size of hydration products. Carbon nanotubes (CNT) are nearly ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. So there is a great potential to utilize CNT in producing new cement based composite materials. It is evident from the review of past literature that mechanical properties of nanotubes reinforced cementitious composites have been highly variable. Some researches yielded improvement in performance of CNT-cement composites as compared to plain cement samples, while other resulted in inconsequential changes in mechanical properties. Even in some cases considerable less strengths and modulus were obtained. Another major difficulty of producing CNT reinforced cementitious composites is the attainment of homogeneous dispersion of nanotubes into cement but no standard procedures to mix CNT within the cement is available. CNT attract more water to adhere to their surface due to their high aspect ratio which eventually results in less workability of the cement mix. Therefore, it is extremely important to develop a suitable mixing technique and an

  18. Throughput Benefit Assessment for Tactical Runway Configuration Management (TRCM)

    NASA Technical Reports Server (NTRS)

    Phojanamongkolkij, Nipa; Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Fenbert, James W.

    2014-01-01

    The System-Oriented Runway Management (SORM) concept is a collection of needed capabilities focused on a more efficient use of runways while considering all of the factors that affect runway use. Tactical Runway Configuration Management (TRCM), one of the SORM capabilities, provides runway configuration and runway usage recommendations, monitoring the active runway configuration for suitability given existing factors, based on a 90 minute planning horizon. This study evaluates the throughput benefits using a representative sample of today's traffic volumes at three airports: Memphis International Airport (MEM), Dallas-Fort Worth International Airport (DFW), and John F. Kennedy International Airport (JFK). Based on this initial assessment, there are statistical throughput benefits for both arrivals and departures at MEM with an average of 4% for arrivals, and 6% for departures. For DFW, there is a statistical benefit for arrivals with an average of 3%. Although there is an average of 1% benefit observed for departures, it is not statistically significant. For JFK, there is a 12% benefit for arrivals, but a 2% penalty for departures. The results obtained are for current traffic volumes and should show greater benefit for increased future demand. This paper also proposes some potential TRCM algorithm improvements for future research. A continued research plan is being worked to implement these improvements and to re-assess the throughput benefit for today and future projected traffic volumes.

  19. Runway Incursion Prevention System for General Aviation Operations

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Prinzel III, Lawrence J.

    2006-01-01

    A Runway Incursion Prevention System (RIPS) and additional incursion detection algorithm were adapted for general aviation operations and evaluated in a simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) in the fall of 2005. RIPS has been designed to enhance surface situation awareness and provide cockpit alerts of potential runway conflicts in order to prevent runway incidents while also improving operational capability. The purpose of the study was to evaluate the airborne incursion detection algorithms and associated alerting and airport surface display concepts for general aviation operations. This paper gives an overview of the system, simulation study, and test results.

  20. Evaluation of a tritium runway-lighting system. Technical note

    SciTech Connect

    Katz, E.S.

    1992-04-01

    A tritium powered runway lighting system was installed and evaluated at the Federal Aviation Administration (FAA) Technical Center. The purpose of this evaluation was to determine if the tritium runway lighting system would safely support Federal Aviation Regulations (FAR) Part 135 commercial operations, during nighttime visual flight rules (VFR) conditions at remote airports. Subject pilots having flight experience levels appropriate for pilots conducting FAR Part 135 air taxi operations were afforded the opportunity of flight testing the system. Results of the evaluation indicate that the tritium runway lighting system does not meet all of the minimum criteria necessary for FAA approval and, therefore, would not guarantee an acceptable level of safety. Tritium Runway Lighting System, Remote Airports.

  1. 3. VIEW OF PARKING APRON LOOKING SOUTHWEST FROM SOUTH RUNWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF PARKING APRON LOOKING SOUTHWEST FROM SOUTH RUNWAY OBSERVATION BUILDING TOWARD BUILDING 8280 (DOUBLE CANTILEVER HANGAR). - Loring Air Force Base, Airfield, Central portion of base, Limestone, Aroostook County, ME

  2. Runway Incursion Prevention System Testing at the Wallops Flight Facility

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.

    2005-01-01

    A Runway Incursion Prevention System (RIPS) integrated with a Synthetic Vision System concept (SVS) was tested at the Reno/Tahoe International Airport (RNO) and Wallops Flight Facility (WAL) in the summer of 2004. RIPS provides enhanced surface situational awareness and alerts of runway conflicts in order to prevent runway incidents while also improving operational capability. A series of test runs was conducted using a Gulfstream-V (G-V) aircraft as the test platform and a NASA test aircraft and a NASA test van as incurring traffic. The purpose of the study, from the RIPS perspective, was to evaluate the RIPS airborne incursion detection algorithms and associated alerting and airport surface display concepts, focusing on crossing runway incursion scenarios. This paper gives an overview of the RIPS, WAL flight test activities, and WAL test results.

  3. 14 CFR 151.11 - Runway clear zones; requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... sponsor or other public agency shows that it is legally able to prevent the future erection or creation of obstructions in the runway clear zone area, and adopts protective measures to prohibit their future erection...

  4. Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

    NASA Astrophysics Data System (ADS)

    Patibandla, Varun chowdary

    The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not

  5. Differential Context Effects in the Comprehension of Abstract and Concrete Verbal Materials.

    ERIC Educational Resources Information Center

    Schwanenflugel, Paula J.; Shoben, Edward J.

    1983-01-01

    Three experiments tested contrasting predictions of a dual-representation theory and a context availability model of concreteness effects in verbal processing. Without context, reading times/lexical decision times for abstract sentences/words were longer than for concrete sentences/words. Rated context availability was a good predictor of reaction…

  6. STS-70 Discovery approaches Runway 33

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Space Shuttle orbiter Discovery approaches KSC's Runway 33, with the Vehicle Assembly Building in the background, marking a successful conclusion to the STS-70 mission. Discovery landed on orbit 143, during the second opportunity of the day. Main gear touchdown was unofficially listed at 8:02 a.m. EDT on July 22, 1995. The orbiter traveled some 3.7 million statute miles during the nearly nine-day flight, which included a one-day extension because of fog and low visibility conditions at the KSC Shuttle Landing Facility. STS-70 was the 24th Shuttle landing at KSC and the 70th Space Shuttle mission. The five-member crew deployed the NASA Tracking and Data Relay Satellite-G (TDRS-G). Crew members were Commander Terence 'Tom' Henricks, Pilot Kevin R. Kregel, and Mission Specialists Nancy Jane Currie, Donald A. Thomas and Mary Ellen Weber. STS-70 also was the maiden flight of the new Block 1 orbiter main engine, which flew in the number one position. The other two engines were of the existing Phase II design.

  7. Aircraft and ground vehicle friction correlation test results obtained under winter runway conditions during joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1988-01-01

    Aircraft and ground vehicle friction data collected during the Joint FAA/NASA Runway Friction Program under winter runway conditions are discussed and test results are summarized. The relationship between the different ground vehicle friction measurements obtained on compacted snow- and ice-covered conditions is defined together with the correlation to aircraft tire friction performance under similar runway conditions.

  8. STS-94 Columbia Landing at KSC (South Runway)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Space Shuttle orbiter Columbia touches down on Runway 33 at KSCs Shuttle Landing Facility at 6:46:34 a.m. EDT with Mission Commander James D. Halsell Jr. and Pilot Susan L. Still at the controls to complete the STS-94 mission. Also on board are Mission Specialist Donald A. Thomas, Mission Specialist Michael L. Gernhardt, Payload Commander Janice Voss, and Payload Specialists Roger K. Crouch and Gregory T. Linteris. During the Microgravity Science Laboratory-1 (MSL-1) mission, the Spacelab module was used to test some of the hardware, facilities and procedures that are planned for use on the International Space Station while the flight crew conducted combustion, protein crystal growth and materials processing experiments. This mission was a reflight of the STS-83 mission that lifted off from KSC in April of this year. That space flight was cut short due to indications of a faulty fuel cell. This was Columbias 11th landing at KSC and the 38th landing at the space center in the history of the Shuttle program.

  9. How Concrete Is Concrete?

    ERIC Educational Resources Information Center

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  10. Diffusion and Leaching Behavior of Radionuclides in Category 3 Waste Encasement Concrete and Soil Fill Material – Summary Report

    SciTech Connect

    Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.; Parker, Kent E.; Clayton, Libby N.; Powers, Laura; Recknagle, Kurtis P.; Wood, Marcus I.

    2011-08-31

    One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Such concrete encasement would contain and isolate the waste packages from the hydrologic environment and would act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expected to have a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed, and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion and move into the surrounding subsurface environment. Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. The retardation factors for radionuclides contained in the waste packages can be determined from measurements of diffusion coefficients for these contaminants through concrete and fill material. Some of the mobilization scenarios include (1) potential leaching of waste form before permanent closure cover is installed; (2) after the cover installation, long-term diffusion of radionuclides from concrete waste form into surrounding fill material; (3) diffusion of radionuclides from contaminated soils into adjoining concrete encasement and clean fill material. Additionally, the rate of

  11. Human risk factors associated with pilots in runway excursions.

    PubMed

    Chang, Yu-Hern; Yang, Hui-Hua; Hsiao, Yu-Jung

    2016-09-01

    A breakdown analysis of civil aviation accidents worldwide indicates that the occurrence of runway excursions represents the largest portion among all aviation occurrence categories. This study examines the human risk factors associated with pilots in runway excursions, by applying a SHELLO model to categorize the human risk factors and to evaluate the importance based on the opinions of 145 airline pilots. This study integrates aviation management level expert opinions on relative weighting and improvement-achievability in order to develop four kinds of priority risk management strategies for airline pilots to reduce runway excursions. The empirical study based on experts' evaluation suggests that the most important dimension is the liveware/pilot's core ability. From the perspective of front-line pilots, the most important risk factors are the environment, wet/containment runways, and weather issues like rain/thunderstorms. Finally, this study develops practical strategies for helping management authorities to improve major operational and managerial weaknesses so as to reduce the human risks related to runway excursions. PMID:27344128

  12. Feasibility Tests on Concrete with Very-High-Volume Supplementary Cementitious Materials

    PubMed Central

    Yang, Keun-Hyeok; Jeon, Yong-Su

    2014-01-01

    The objective of this study is to examine the compressive strength and durability of very high-volume SCM concrete. The prepared 36 concrete specimens were classified into two groups according to their designed 28-day compressive strength. For the high-volume SCM, the FA level was fixed at a weight ratio of 0.4 and the GGBS level varied between the weight ratio of 0.3 and 0.5, which resulted in 70–90% replacement of OPC. To enhance the compressive strength of very high-volume SCM concrete at an early age, the unit water content was controlled to be less than 150 kg/m3, and a specially modified polycarboxylate-based water-reducing agent was added. Test results showed that as SCM ratio (RSCM) increased, the strength gain ratio at an early age relative to the 28-day strength tended to decrease, whereas that at a long-term age increased up to RSCM of 0.8, beyond which it decreased. In addition, the beneficial effect of SCMs on the freezing-and-thawing and chloride resistances of the concrete decreased at RSCM of 0.9. Hence, it is recommended that RSCM needs to be restricted to less than 0.8–0.85 in order to obtain a consistent positive influence on the compressive strength and durability of SCM concrete. PMID:25162049

  13. Feasibility tests on concrete with very-high-volume supplementary cementitious materials.

    PubMed

    Yang, Keun-Hyeok; Jeon, Yong-Su

    2014-01-01

    The objective of this study is to examine the compressive strength and durability of very high-volume SCM concrete. The prepared 36 concrete specimens were classified into two groups according to their designed 28-day compressive strength. For the high-volume SCM, the FA level was fixed at a weight ratio of 0.4 and the GGBS level varied between the weight ratio of 0.3 and 0.5, which resulted in 70-90% replacement of OPC. To enhance the compressive strength of very high-volume SCM concrete at an early age, the unit water content was controlled to be less than 150 kg/m(3), and a specially modified polycarboxylate-based water-reducing agent was added. Test results showed that as SCM ratio (R SCM) increased, the strength gain ratio at an early age relative to the 28-day strength tended to decrease, whereas that at a long-term age increased up to R SCM of 0.8, beyond which it decreased. In addition, the beneficial effect of SCMs on the freezing-and-thawing and chloride resistances of the concrete decreased at R SCM of 0.9. Hence, it is recommended that R SCM needs to be restricted to less than 0.8-0.85 in order to obtain a consistent positive influence on the compressive strength and durability of SCM concrete. PMID:25162049

  14. A Runway Surface Monitor using Internet of Things

    NASA Astrophysics Data System (ADS)

    Troiano, Amedeo; Pasero, Eros

    2014-05-01

    The monitoring of runway surfaces, for the detection of ice formation or presence of water, is an important issue for reducing maintenance costs and improving traffic safety. An innovative sensor was developed to detect the presence of ice or water on its surface, and its repeatability, stability and reliability were assessed in different simulations and experiments, performed both in laboratory and in the field. Three sensors were embedded in the runway of the Turin-Caselle airport, in the north-west of Italy, to check the state of its surface. Each sensor was connected to a GPRS modem to send the collected data to a common database. The entire system was installed about three years ago, and up to now it shows correct work and automatic reactivation after malfunctions without any external help. The state of the runway surface is virtual represented in an internet website, using the Internet of Things features and opening new scenarios.

  15. Aircraft and Ground Vehicle Winter Runway Friction Assessment

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1999-01-01

    Some background information is given together with the scope and objectives of a 5-year, Joint Winter Runway Friction Measurement Program between the National Aeronautics & Space Administration (NASA), Transport Canada (TC), and the Federal Aviation Administration (FAA). The primary objective of this effort is to perform instrumented aircraft and ground vehicle tests aimed at identifying a common number that all the different ground vehicle devices would report. This number, denoted the International Runway Friction Index (IRFI), will be related to all types of aircraft stopping performance. The range of test equipment, the test sites, test results and accomplishments, the extent of the substantial friction database compiled, and future test plans will be described. Several related studies have also been implemented including the effects of contaminant type on aircraft impingement drag, and the effectiveness of various runway and aircraft de-icing chemical types, and application rates.

  16. Black Box Testing: Experiments with Runway Incursion Advisory Alerting System

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi

    2005-01-01

    This report summarizes our research findings on the Black box testing of Runway Incursion Advisory Alerting System (RIAAS) and Runway Safety Monitor (RSM) system. Developing automated testing software for such systems has been a problem because of the extensive information that has to be processed. Customized software solutions have been proposed. However, they are time consuming to develop. Here, we present a less expensive, and a more general test platform that is capable of performing complete black box testing. The technique is based on the classification of the anomalies that arise during Monte Carlo simulations. In addition, we also discuss a generalized testing tool (prototype) that we have developed.

  17. Aluminum runway surface as possible aid to aircraft braking

    NASA Technical Reports Server (NTRS)

    Miller, C. D.; Pinkel, I. I.

    1973-01-01

    Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

  18. Nondestructive identification of material properties of fibre concrete: A stationary magnetic field

    NASA Astrophysics Data System (ADS)

    Hobst, L.; Bílek, P.

    2016-06-01

    Mechanical properties of fibre concrete are determined by volume fraction and orientation of metal fibres in a cementitious matrix, thus nondestructive or (at least) low-invasive experimental testing and computational identification approaches are needed. This paper demonstrates the approach relying on the different magnetic permeability of fibres and a matrix, utilizing the Hall probe, as an alternative of results based image processing.

  19. RECYCLED MATERIALS FOR REPAIR AND REHABILITATION OF AGING CONCRETE STRUCTURES - PHASE I

    EPA Science Inventory

    Exterior wrapping of concrete columns initially was developed for seismic reinforcement in high-risk areas such as California. As the technology has gained acceptance, it is being considered for use in extending column life, reducing corrosion, and preventing spalling. All ...

  20. College Readers' Mental Imagery, Comprehension and Attitude with Abstract and Concrete Expository Materials.

    ERIC Educational Resources Information Center

    Irwin, Judith W.; Witte, Pauline L.

    1980-01-01

    A study was made of the relationships between the number and clarity of mental images reported by college readers and their reported interest, perceived reading ease, and comprehension scores. Imagery ratings were not significantly related to comprehension scores, but for concrete passages they were significantly related to attitude and reading…

  1. Nondestructive identification of material properties of fibre concrete: A time-harmonic electromagnetic field

    NASA Astrophysics Data System (ADS)

    Hobst, L.; Bílek, P.

    2016-06-01

    The magnetic approach to the identification of mechanical properties of fibre concrete, using permanent magnets, has its electromagnetic alternative, more suitable to the nondestructive detection of orientation of fibres, in addition to the evaluation of their volume fraction. This paper sketches related approaches to both experimental settings and computational simulations.

  2. The durability of concrete containing a high-level of fly ash or a ternary blend of supplementary cementing materials

    NASA Astrophysics Data System (ADS)

    Gilbert, Christine M.

    The research for this study was conducted in two distinct phases as follows: Phase 1: The objective was to determine the effect of fly ash on the carbonation of concrete. The specimens made for this phase of the study were larger in size than those normally used in carbonation studies and were are meant to more accurately reflect real field conditions. The results from early age carbonation testing indicate that the larger size specimens do not have a measured depth of carbonation as great as that of the smaller specimens typically used in carbonation studies at the same age and under the same conditions. Phase 2: The objective was to evaluate the performance of ternary concrete mixes containing a ternary cement blend consisting of Portland cement, slag and Type C fly ash. It was found that concrete mixtures containing the fly ash with the lower calcium (CaO) content (in binary or ternary blends) provided superior durability performance and resistance to ASR compared to that of the fly ash with the higher CaO content. Ternary blends (regardless of the CaO content of the fly ash) provided better overall durability performance than binary blends of cementing materials or the control.

  3. Measures to increase airfield capacity by changing aircraft runway occupancy characteristics

    NASA Technical Reports Server (NTRS)

    Gosling, G. D.; Kanafani, A.; Rockaday, S. L. M.

    1981-01-01

    Airfield capacity and aircraft runway occupancy characteristics were studied. Factors that caused runway congestion and airfield crowding were identified. Several innovations designed to alleviate the congestion are discussed. Integrated landing management, the concept that the operation of the final approach and runway should be considered in concert, was identified as underlying all of the innovations.

  4. 76 FR 67018 - Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather Information Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ... Federal Aviation Administration Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather... of In-Pavement Stationary Runway Weather Information Systems. SUMMARY: Projects funded under the... Active or Passive In- Pavement Stationary Runway Weather Information Systems that meet the...

  5. Parallel runway requirement analysis study. Volume 2: Simulation manual

    NASA Technical Reports Server (NTRS)

    Ebrahimi, Yaghoob S.; Chun, Ken S.

    1993-01-01

    This document is a user manual for operating the PLAND_BLUNDER (PLB) simulation program. This simulation is based on two aircraft approaching parallel runways independently and using parallel Instrument Landing System (ILS) equipment during Instrument Meteorological Conditions (IMC). If an aircraft should deviate from its assigned localizer course toward the opposite runway, this constitutes a blunder which could endanger the aircraft on the adjacent path. The worst case scenario would be if the blundering aircraft were unable to recover and continue toward the adjacent runway. PLAND_BLUNDER is a Monte Carlo-type simulation which employs the events and aircraft positioning during such a blunder situation. The model simulates two aircraft performing parallel ILS approaches using Instrument Flight Rules (IFR) or visual procedures. PLB uses a simple movement model and control law in three dimensions (X, Y, Z). The parameters of the simulation inputs and outputs are defined in this document along with a sample of the statistical analysis. This document is the second volume of a two volume set. Volume 1 is a description of the application of the PLB to the analysis of close parallel runway operations.

  6. General view of runway 33 at the Kennedy Space Center ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of runway 33 at the Kennedy Space Center looking at the ground support equipment and the aft and starboard side of the Orbiter Discovery as the orbiter is undergoing post flight processing and preparations to be towed to the Orbiter Processing Facility. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  7. General view of runway 33 at the Kennedy Space Center ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of runway 33 at the Kennedy Space Center looking at the ground support equipment and the aft and port side of the Orbiter Discovery as the orbiter is undergoing post flight processing and preparations to be towed to the Orbiter Processing Facility. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  8. General view of the Orbiter Discovery on runway 33 at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of the Orbiter Discovery on runway 33 at Kennedy Space Center shortly after landing. The orbiter is processed and prepared for being towed to the Orbiter Processing Facility for continued post flight processing and pre flight preparations for its next mission. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. General view of runway 33 at the Kennedy Space Center ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of runway 33 at the Kennedy Space Center looking at the ground support equipment and the port side of the Orbiter Discovery as the orbiter is undergoing post flight processing and preparations to be towed to the Orbiter Processing Facility. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  10. System-Oriented Runway Management Concept of Operations

    NASA Technical Reports Server (NTRS)

    Lohr, Gary W.; Atkins, Stephen

    2015-01-01

    This document describes a concept for runway management that maximizes the overall efficiency of arrival and departure operations at an airport or group of airports. Specifically, by planning airport runway configurations/usage, it focuses on the efficiency with which arrival flights reach their parking gates from their arrival fixes and departure flights exit the terminal airspace from their parking gates. In the future, the concept could be expanded to include the management of other limited airport resources. While most easily described in the context of a single airport, the concept applies equally well to a group of airports that comprise a metroplex (i.e., airports in close proximity that share resources such that operations at the airports are at least partially dependent) by including the coordination of runway usage decisions between the airports. In fact, the potential benefit of the concept is expected to be larger in future metroplex environments due to the increasing need to coordinate the operations at proximate airports to more efficiently share limited airspace resources. This concept, called System-Oriented Runway Management (SORM), is further broken down into a set of airport traffic management functions that share the principle that operational performance must be measured over the complete surface and airborne trajectories of the airport's arrivals and departures. The "system-oriented" term derives from the belief that the traffic management objective must consider the efficiency of operations over a wide range of aircraft movements and National Airspace System (NAS) dynamics. The SORM concept is comprised of three primary elements: strategic airport capacity planning, airport configuration management, and combined arrival/departure runway planning. Some aspects of the SORM concept, such as using airport configuration management1 as a mechanism for improving aircraft efficiency, are novel. Other elements (e.g., runway scheduling, which is a part

  11. Production of high strength concrete

    SciTech Connect

    Peterman, M.B.; Carrasquillo, R.L.

    1986-01-01

    The criteria for selection of concrete materials and their proportions to producer uniform, economical, high strength concrete are presented in this book. The recommendations provided are based on a study of the interactions among components of plain concrete and mix proportions, and of their contribution to the compressive strength of high strength concrete. These recommendations will serve as guidelines to practicing engineers, in the selection of materials and their proportions for the production of high strength concrete. Increasing demands for improved efficiency and reduced construction costs have resulted in engineers beginning to design large structures using higher strength concrete at higher stress levels. There are definite advantages, both technical and economical, in using high strength concrete. For example, for a given cross section, prestresses concrete bridge girders can carry greater service loads across longer spans if made using high strength concrete. In addition, cost comparisons have shown that the savings obtained are significantly greater than the added cost of the higher quality concrete.

  12. STS-31 on Runway 22 at Edwards with Recovery Personnel

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Personnel and equipment converge on the orbiter Discovery to begin servicing the spacecraft following its landing April 29, 1990, at NASA's then Ames-Dryden Flight Research Facility, Edwards, California. Post-landing servicing by the recovery convoy is carried out after each Space Shuttle landing and includes safety checks for flammable and toxic gases escaping from systems aboard the orbiters, hooking up engine fuel purge and equipment coolant lines, and inspecting the brakes before the vehicle is towed from the runway to the shuttle facility at Dryden where it is prepared for the ferry flight back to the Kennedy Space Center in Florida. Up to 24 vehicles and scores of personnel make up the landing recovery convoys at Dryden. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain

  13. Quantitative linear and nonlinear resonance inspection techniques and analysis for material characterization: application to concrete thermal damage.

    PubMed

    Payan, C; Ulrich, T J; Le Bas, P Y; Saleh, T; Guimaraes, M

    2014-08-01

    Developed in the late 1980s, Nonlinear Resonant Ultrasound Spectroscopy (NRUS) has been widely employed in the field of material characterization. Most of the studies assume the measured amplitude to be proportional to the strain amplitude which drives nonlinear phenomena. In 1D resonant bar experiments, the configuration for which NRUS was initially developed, this assumption holds. However, it is not true for samples of general shape which exhibit several resonance mode shapes. This paper proposes a methodology based on linear resonant ultrasound spectroscopy, numerical simulations and nonlinear resonant ultrasound spectroscopy to provide quantitative values of nonlinear elastic moduli taking into account the 3D nature of the samples. In the context of license renewal in the field of nuclear energy, this study aims at providing some quantitative information related to the degree of micro-cracking of concrete and cement based materials in the presence of thermal damage. The resonance based method is validated as regard with concrete microstructure evolution during thermal exposure. PMID:25096088

  14. E-Area Vault Concrete Material Property And Vault Durability/Degradation Projection Recommendations

    SciTech Connect

    Phifer, M. A.

    2014-03-11

    Subsequent to the 2008 E-Area Low-Level Waste Facility (ELLWF) Performance Assessment (PA) (WSRC 2008), two additional E-Area vault concrete property testing programs have been conducted (Dixon and Phifer 2010 and SIMCO 2011a) and two additional E-Area vault concrete durability modeling projections have been made (Langton 2009 and SIMCO 2012). All the information/data from these reports has been evaluated and consolidated herein by the Savannah River National Laboratory (SRNL) at the request of Solid Waste Management (SWM) to produce E-Area vault concrete hydraulic and physical property data and vault durability/degradation projection recommendations that are adequately justified for use within associated Special Analyses (SAs) and future PA updates. The Low Activity Waste (LAW) and Intermediate Level (IL) Vaults structural degradation predictions produced by Carey 2006 and Peregoy 2006, respectively, which were used as the basis for the 2008 ELLWF PA, remain valid based upon the results of the E-Area vault concrete durability simulations reported by Langton 2009 and those reported by SIMCO 2012. Therefore revised structural degradation predictions are not required so long as the mean thickness of the closure cap overlying the vaults is no greater than that assumed within Carey 2006 and Peregoy 2006. For the LAW Vault structural degradation prediction (Carey 2006), the mean thickness of the overlying closure cap was taken as nine feet. For the IL Vault structural degradation prediction (Peregoy 2006), the mean thickness of the overlying closure cap was taken as eight feet. The mean closure cap thicknesses as described here for both E-Area Vaults will be included as a key input and assumption (I&A) in the next revision to the closure plan for the ELLWF (Phifer et al. 2009). In addition, it has been identified as new input to the PA model to be assessed in the ongoing update to the new PA Information UDQE (Flach 2013). Once the UDQE is approved, the SWM Key I

  15. Uncertainty Analysis for the Evaluation of a Passive Runway Arresting System

    NASA Technical Reports Server (NTRS)

    Deloach, Richard; Marlowe, Jill M.; Yager, Thomas J.

    2009-01-01

    This paper considers the stopping distance of an aircraft involved in a runway overrun incident when the runway has been provided with an extension comprised of a material engineered to induce high levels of rolling friction and drag. A formula for stopping distance is derived that is shown to be the product of a known formula for the case of friction without drag, and a dimensionless constant between 0 and 1 that quantifies the further reduction in stopping distance when drag is introduced. This additional quantity, identified as the Drag Reduction Factor, D, is shown to depend on the ratio of drag force to friction force experienced by the aircraft as it enters the overrun area. The specific functional form of D is shown to depend on how drag varies with speed. A detailed uncertainty analysis is presented which reveals how the uncertainty in estimates of stopping distance are influenced by experimental error in the force measurements that are acquired in a typical evaluation experiment conducted to assess candidate overrun materials.

  16. Field site leaching from recycled concrete aggregates applied as sub-base material in road construction.

    PubMed

    Engelsen, Christian J; Wibetoe, Grethe; van der Sloot, Hans A; Lund, Walter; Petkovic, Gordana

    2012-06-15

    The release of major and trace elements from recycled concrete aggregates used in an asphalt covered road sub-base has been monitored for more than 4 years. A similar test field without an asphalt cover, directly exposed to air and rain, and an asphalt covered reference field with natural aggregates in the sub-base were also included in the study. It was found that the pH of the infiltration water from the road sub-base with asphalt covered concrete aggregates decreased from 12.6 to below pH 10 after 2.5 years of exposure, whereas this pH was reached within only one year for the uncovered field. Vertical temperature profiles established for the sub-base, could explain the measured infiltration during parts of the winter season. When the release of major and trace elements as function of field pH was compared with pH dependent release data measured in the laboratory, some similar pH trends were found. The field concentrations of Cd, Ni, Pb and Zn were found to be low throughout the monitoring period. During two of the winter seasons, a concentration increase of Cr and Mo was observed, possibly due to the use of de-icing salt. The concentrations of the trace constituents did not exceed Norwegian acceptance criteria for ground water and surface water Class II. PMID:22554532

  17. Advance Organizers: Concret Versus Abstract.

    ERIC Educational Resources Information Center

    Corkill, Alice J.; And Others

    1988-01-01

    Two experiments examined the relative effects of concrete and abstract advance organizers on students' memory for subsequent prose. Results of the experiments are discussed in terms of the memorability, familiarity, and visualizability of concrete and abstract verbal materials. (JD)

  18. Enhanced detection of LED runway/approach lights for EVS

    NASA Astrophysics Data System (ADS)

    Kerr, J. Richard

    2008-04-01

    The acquisition of approach and runway lights by an imager is critical to landing-credit operations with EVS. Using a GPS clock, LED sources are pulsed at one-half the EVS video rate of 60 Hz or more. The camera then uses synchronous (lock-in) detection to store the imaged lights in alternate frames, with digital subtraction of the background for each respective frame-pair. Range and weather penetration, limited only by detector background shot-noise (or camera system noise at night), substantially exceed that of the human eye. An alternative is the use of short-wave infrared cameras with eyesafe laser diode emitters. Also, runway identification may be encoded on the pulses. With standardized cameras and emitters, an "instrument qualified visual range" may be established. The concept extends to portable beacons at austere airfields, and to see-and-avoid sensing of other aircraft including UAVs.

  19. NASA Research For Instrument Approaches To Closely Spaced Parallel Runways

    NASA Technical Reports Server (NTRS)

    Elliott, Dawn M.; Perry, R. Brad

    2000-01-01

    Within the NASA Aviation Systems Capacity Program, the Terminal Area Productivity (TAP) Project is addressing airport capacity enhancements during instrument meteorological condition (IMC). The Airborne Information for Lateral Spacing (AILS) research within TAP has focused on an airborne centered approach for independent instrument approaches to closely spaced parallel runways using Differential Global Positioning System (DGPS) and Automatic Dependent Surveillance-Broadcast (ADS-B) technologies. NASA Langley Research Center (LaRC), working in partnership with Honeywell, Inc., completed in AILS simulation study, flight test, and demonstration in 1999 examining normal approaches and potential collision scenarios to runways with separation distances of 3,400 and 2,500 feet. The results of the flight test and demonstration validate the simulation study.

  20. Development of a Bayesian Belief Network Runway Incursion Model

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.

    2014-01-01

    In a previous paper, a statistical analysis of runway incursion (RI) events was conducted to ascertain their relevance to the top ten Technical Challenges (TC) of the National Aeronautics and Space Administration (NASA) Aviation Safety Program (AvSP). The study revealed connections to perhaps several of the AvSP top ten TC. That data also identified several primary causes and contributing factors for RI events that served as the basis for developing a system-level Bayesian Belief Network (BBN) model for RI events. The system-level BBN model will allow NASA to generically model the causes of RI events and to assess the effectiveness of technology products being developed under NASA funding. These products are intended to reduce the frequency of RI events in particular, and to improve runway safety in general. The development, structure and assessment of that BBN for RI events by a Subject Matter Expert panel are documented in this paper.

  1. Runway Exit Designs for Capacity Improvement Demonstrations. Phase 1: Algorithm Development

    NASA Technical Reports Server (NTRS)

    Trani, A. A.; Hobeika, A. G.; Sherali, H.; Kim, B. J.; Sadam, C. K.

    1990-01-01

    A description and results are presented of a study to locate and design rapid runway exits under realistic airport conditions. The study developed a PC-based computer simulation-optimization program called REDIM (runway exit design interactive model) to help future airport designers and planners to locate optimal exits under various airport conditions. The model addresses three sets of problems typically arising during runway exit design evaluations. These are the evaluations of existing runway configurations, addition of new rapid runway turnoffs, and the design of new runway facilities. The model is highly interactive and allows a quick estimation of the expected value of runway occupancy time. Aircraft populations and airport environmental conditions are among the multiple inputs to the model to execute a viable runway location and geometric design solution. The results presented suggest that possible reductions on runway occupancy time (ROT) can be achieved with the use of optimally tailored rapid runway designs for a given aircraft population. Reductions of up to 9 to 6 seconds are possible with the implementation of 30 m/sec variable geometry exits.

  2. The noise impact of proposed runway alternatives at Craig Airport

    NASA Technical Reports Server (NTRS)

    Deloach, R.

    1982-01-01

    Four proposed runway expansion alternatives at Craig Airport in Jacksonville, Florida have been assessed with respect to their forecasted noise impact in the year 2005. The assessment accounts for population distributions around the airport and human subjective response to noise, as well as the distribution of noise levels in the surrounding community (footprints). The impact analysis was performed using the Airport-noise Levels and Annoyance Model (ALAMO), an airport community response model recently developd at Langley Research Center.

  3. Benefits Assessment for Tactical Runway Configuration Management Tool

    NASA Technical Reports Server (NTRS)

    Oseguera-Lohr, Rosa; Phojanamongkolkij, Nipa; Lohr, Gary; Fenbert, James W.

    2013-01-01

    The Tactical Runway Configuration Management (TRCM) software tool was developed to provide air traffic flow managers and supervisors with recommendations for airport configuration changes and runway usage. The objective for this study is to conduct a benefits assessment at Memphis (MEM), Dallas Fort-Worth (DFW) and New York's John F. Kennedy (JFK) airports using the TRCM tool. Results from simulations using the TRCM-generated runway configuration schedule are compared with results using historical schedules. For the 12 days of data used in this analysis, the transit time (arrival fix to spot on airport movement area for arrivals, or spot to departure fix for departures) for MEM departures is greater (7%) than for arrivals (3%); for JFK, there is a benefit for arrivals (9%) but not for departures (-2%); for DFW, arrivals show a slight benefit (1%), but this is offset by departures (-2%). Departure queue length benefits show fewer aircraft in queue for JFK (29%) and MEM (11%), but not for DFW (-13%). Fuel savings for surface operations at MEM are seen for both arrivals and departures. At JFK there are fuel savings for arrivals, but these are offset by increased fuel use for departures. In this study, no surface fuel benefits resulted for DFW. Results suggest that the TRCM algorithm requires modifications for complex surface traffic operations that can cause taxi delays. For all three airports, the average number of changes in flow direction (runway configuration) recommended by TRCM was many times greater than the historical data; TRCM would need to be adapted to a particular airport's needs, to limit the number of changes to acceptable levels. The results from this analysis indicate the TRCM tool can provide benefits at some high-capacity airports. The magnitude of these benefits depends on many airport-specific factors and would require adaptation of the TRCM tool; a detailed assessment is needed prior to determining suitability for a particular airport.

  4. ELWIRA "Plants, wood, steel, concrete - a lifecycle as construction materials": University meets school - science meets high school education

    NASA Astrophysics Data System (ADS)

    Strauss-Sieberth, Alexandra; Strauss, Alfred; Kalny, Gerda; Rauch, Hans Peter; Loiskandl, Willibald

    2016-04-01

    The research project "Plants, wood, steel, concrete - a lifecycle as construction materials" (ELWIRA) is in the framework of the Sparkling Science programme performed by the University of Natural Resources and Life Sciences together with the Billroth Gymnasium in Vienna. The targets of a Sparkling Science project are twofold (a) research and scientific activities should already be transferred in the education methods of schools in order to fascinate high school students for scientific methods and to spark young people's interest in research, and (b) exciting research questions not solved and innovative findings should be addressed. The high school students work together with the scientists on their existing research questions improve the school's profile and the high school student knowledge in the investigated Sparkling Science topic and can lead to a more diverse viewing by the involvement of the high school students. In the project ELWIRA scientists collaborate with the school to quantify and evaluate the properties of classical building materials like concrete and natural materials like plants and woodlogs in terms of their life cycle through the use of different laboratory and field methods. The collaboration with the high school students is structured in workshops, laboratory work and fieldworks. For an efficient coordination/communication, learning and research progress new advanced electronic media like "Moodle classes/courses" have been used and utilized by the high school students with great interest. The Moodle classes are of high importance in the knowledge transfer in the dialogue with the high school students. The research project is structured into four main areas associated with the efficiencies of building materials: (a) the aesthetic feeling of people in terms of the appearance of materials and associated structures will be evaluated by means of jointly developed and collected questionnaires. The analysis, interpretation and evaluation are carried

  5. Aircraft and Ground Vehicle Winter Runway Friction Assessment

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1999-01-01

    Some background information is given together with the scope and objectives of a 5-year, Joint Winter Runway Friction Measurement Program between the National Aeronautics & Space Administration (NASA), Transport Canada (TC), and the Federal Aviation Administration (FAA). Participants recently completed the fourth winter season of testing. The primary objective of this effort is to perform instrumented aircraft and ground vehicle tests aimed at identifying a common number that all the different ground vehicle devices would report. This number, denoted the International Runway Friction Index (IRFI) will be related to all types of aircraft stopping performance. The range of test equipment, the test sites, test results and accomplishments, the extent of the substantial friction database compiled, and future test plans will be described. Several related studies have also been implemented including the effects of contaminant type on aircraft impingement drag and the effectiveness of various runway and aircraft de-icing chemical types and application rates. New equipment and techniques to measure surface frictional properties are also described. The status of an international friction index calibration device for use in ensuring accuracy of ground vehicle friction measurements will also be discussed. NASA considers the success of this joint program critical in terms of ensuring adequate ground handling capability in adverse weather conditions for future aircraft being designed and developed as well as improving the safety of current aircraft ground operations.

  6. Some considerations in the evaluation of concrete as a structural material for alternative LLW (low-level radioactive waste) disposal technologies

    SciTech Connect

    MacKenzie, D.R.; Siskind, B.; Bowerman, B.S.; Piciulo, P.L.

    1987-01-01

    The objective of this study was to develop information needed to evaluate the long-term performance of concrete and reinforced concrete as a structural material for alternative LLW disposal methods. The capability to carry out such an evaluation is required for licensing a site which employs one of these alternative methods. The basis for achieving the study objective was the review and analysis of the literature on concrete and its properties, particularly its durability. In carrying out this program characteristics of concrete useful in evaluating its performance and factors that can affect its performance were identified. The factors are both intrinsic, i.e., associated with composition of the concrete (and thus controllable), and extrinsic, i.e., due to external environmental forces such as climatic conditions and aggressive chemicals in the soil. The testing of concrete, using both accelerated tests and long-term non-accelerated tests, is discussed with special reference to its application to modeling of long-term performance prediction. On the basis of the study's results, conditions for acceptance are recommended as an aid in the licensing of disposal sites which make use of alternative methods.

  7. Parallel runway requirement analysis study. Volume 1: The analysis

    NASA Technical Reports Server (NTRS)

    Ebrahimi, Yaghoob S.

    1993-01-01

    The correlation of increased flight delays with the level of aviation activity is well recognized. A main contributor to these flight delays has been the capacity of airports. Though new airport and runway construction would significantly increase airport capacity, few programs of this type are currently underway, let alone planned, because of the high cost associated with such endeavors. Therefore, it is necessary to achieve the most efficient and cost effective use of existing fixed airport resources through better planning and control of traffic flows. In fact, during the past few years the FAA has initiated such an airport capacity program designed to provide additional capacity at existing airports. Some of the improvements that that program has generated thus far have been based on new Air Traffic Control procedures, terminal automation, additional Instrument Landing Systems, improved controller display aids, and improved utilization of multiple runways/Instrument Meteorological Conditions (IMC) approach procedures. A useful element to understanding potential operational capacity enhancements at high demand airports has been the development and use of an analysis tool called The PLAND_BLUNDER (PLB) Simulation Model. The objective for building this simulation was to develop a parametric model that could be used for analysis in determining the minimum safety level of parallel runway operations for various parameters representing the airplane, navigation, surveillance, and ATC system performance. This simulation is useful as: a quick and economical evaluation of existing environments that are experiencing IMC delays, an efficient way to study and validate proposed procedure modifications, an aid in evaluating requirements for new airports or new runways in old airports, a simple, parametric investigation of a wide range of issues and approaches, an ability to tradeoff air and ground technology and procedures contributions, and a way of considering probable

  8. Applications for concrete offshore

    SciTech Connect

    Not Available

    1982-01-01

    The report collects and summarizes the various proposals for development offshore which have in common the use of concrete as the main structural material, and where possible, indicates their relative feasibility. A study encompassing such diverse schemes as offshore windmills, concrete LNG carriers, hydrocarbon production platforms and floating airports cannot be completely exhaustive on each subject, so references to sources of further information have been given wherever possible. Details of individual projects and proposals are included for Power plants, Hydrocarbon production platforms, Concrete ships, Storage systems and industrial plants, Subsea systems, Offshore islands, Coastal works and Other concrete structures.

  9. Process for impregnating a concrete or cement body with a polymeric material

    DOEpatents

    Mattus, A.J.; Spence, R.D.

    1988-05-04

    A process for impregnating cementitious solids with polymeric materials by blending polymeric materials in a grout, allowing the grout to cure, and contacting the resulting solidified grout containing the polymeric materials with an organic mixture containing a monomer, a cross-linking agent and a catalyst. The mixture dissolves the polymerized particles and forms a channel for distributing the monomer throughout the network formed by the polymeric particles. The organic components are then cured to form a substantially water-impermeable mass.

  10. Process for impregnating a concrete or cement body with a polymeric material

    DOEpatents

    Mattus, Alfred J.; Spence, Roger D.

    1989-01-01

    A process for impregnating cementitious solids with polymeric materials by blending polymeric materials in a grout, allowing the grout to cure, and contacting the resulting solidified grout containing the polymeric materials with an organic mixture containing a monomer, a cross-linking agent and a catalyst. The mixture dissolves the polymerized particles and forms a channel for distributing the monomer throughout the network formed by the polymeric particles. The organic components are then cured to form a substantially water-impermeable mass.

  11. Determination of some radionucluides and heavy elements concentrations in concrete raw materials

    NASA Astrophysics Data System (ADS)

    ElFaham, Mohamed M.; Khalil, Osama M.; Elhassan, Asmaa; Salama, S.

    2015-08-01

    The presence of natural radionuclides in raw materials used in cement manufacturing was determined by using analytical methods. The used Raw materials are limestone, clay, slag, and gypsum, which be used with different concentrations in cement production. Different analytical techniques such as Laser Induced Breakdown Spectroscopy (LIBS) technique, Gamma spectroscopy, Inductively Coupled Plasma (ICP) spectroscopy, X-ray fluorescence spectroscopy (XRF), in addition to X-Ray Diffraction (XRD) for phase identification of a crystalline material. The obtained data show that there is no significant radiological hazards arising from using the present cement components in the different applications. XRD data shows that there is no crystalline structures in the raw materials.

  12. Benefit Assessment for Metroplex Tactical Runway Configuration Management (mTRCM) in a Simulated Environment

    NASA Technical Reports Server (NTRS)

    Phojanamongkolkij, Nipa; Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Robbins, Steven W.; Fenbert, James W.; Hartman, Christopher L.

    2015-01-01

    The System-Oriented Runway Management (SORM) concept is a collection of capabilities focused on a more efficient use of runways while considering all of the factors that affect runway use. Tactical Runway Configuration Management (TRCM), one of the SORM capabilities, provides runway configuration and runway usage recommendations, and monitoring the active runway configuration for suitability given existing factors. This report focuses on the metroplex environment, with two or more proximate airports having arrival and departure operations that are highly interdependent. The myriad of factors that affect metroplex opeations require consideration in arriving at runway configurations that collectively best serve the system as a whole. To assess the metroplex TRCM (mTRCM) benefit, the performance metrics must be compared with the actual historical operations. The historical configuration schedules can be viewed as the schedules produced by subject matter experts (SMEs), and therefore are referred to as the SMEs' schedules. These schedules were obtained from the FAA's Aviation System Performance Metrics (ASPM) database; this is the most representative information regarding runway configuration selection by SMEs. This report focused on a benefit assessment of total delay, transit time, and throughput efficiency (TE) benefits using the mTRCM algorithm at representative volumes for today's traffic at the New York metroplex (N90).

  13. The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching of Constituents from Cements and Concretes

    EPA Science Inventory

    The objective of this report is to compare the leaching of portland cement-based materials that have been prepared with and without coal combustion fly ash to illustrate whether there is evidence that the use of fly ash in cement and concrete products may result in increased leac...

  14. STS-36 on Edwards Runway with Recovery Personnel

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Personnel and equipment converge on the orbiter Atlantis to begin servicing the spacecraft following its landing 4 March 1990, at NASA's then Ames-Dryden Flight Research Facility, Edwards, California. Mission elapsed time for the Department of Defense mission was 4 days, 10 hours, 19 minutes and 15 seconds. Actual landing time was 10:08 a.m. Post-landing servicing by the recovery convoy is carried out after each Space Shuttle landing and includes safety checks for flammable and toxic gases escaping from systems aboard the orbiters, hooking up engine fuel purge and equipment coolant lines, and inspecting the brakes before the vehicle is towed from the runway to the shuttle facility at Dryden where it is prepared for the ferry flight back to the Kennedy Space Center in Florida. Up to 24 vehicles and scores of personnel make up the landing recovery convoys at Dryden. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed

  15. STS-31 on Runway 22 at Edwards with Recovery Personnel

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Personnel and equipment converge on the orbiter Discovery to begin servicing the spacecraft following its landing April 29, 1990, at NASA's then Ames-Dryden Flight Research Facility, Edwards, California. Post-landing servicing by the recovery convoy is carried out after each Space Shuttle landing and includes safety checks for flammable and toxic gases escaping from systems aboard the orbiters, hooking up engine fuel purge and equipment coolant lines, and inspecting the brakes before the vehicle is towed from the runway to the shuttle facility at Dryden where it is prepared for the ferry flight back to the Kennedy Space Center in Florida. Up to 24 vehicles and scores of personnel make up the landing recovery convoys at Dryden. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain

  16. STS-36 on Edwards Runway with Recovery Personnel

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Personnel and equipment converge on the orbiter Atlantis to begin servicing the spacecraft following its landing 4 March 1990, at NASA's then Ames-Dryden Flight Research Facility, Edwards, California. Mission elapsed time for the Department of Defense mission was 4 days, 10 hours, 19 minutes and 15 seconds. Actual landing time was 10:08 a.m. Post-landing servicing by the recovery convoy is carried out after each Space Shuttle landing and includes safety checks for flammable and toxic gases escaping from systems aboard the orbiters, hooking up engine fuel purge and equipment coolant lines, and inspecting the brakes before the vehicle is towed from the runway to the shuttle facility at Dryden where it is prepared for the ferry flight back to the Kennedy Space Center in Florida. Up to 24 vehicles and scores of personnel make up the landing recovery convoys at Dryden. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed

  17. Factors that determine depth perception of trapezoids, windsurfers, runways

    PubMed Central

    Tseng, Chia-Huei; Gobell, Joetta L.; Sperling, George

    2015-01-01

    We report here a windsurfer1 illusion, a naturally occurring trapezoidal illusion in which the small end of the sail viewed at a distance appears to be pointed away from the observer even when it is closer. This naturally occurring illusion is so compelling that observers are unaware of their gross perceptual misinterpretation of the scene. Four laboratory experiment of this kind of trapezoidal illusion investigated the joint effects of retinal orientation, head position, relative motion, and the relative direction of gravity on automatic depth perception. Observers viewed two adjacent white trapezoids outlined on a black background rotating back and forth ± 20° on a vertical axis much like the sails of two adjacent windsurfers. Observers reported which side of the trapezoids (long or short) appeared to be closer to them (i.e., in front). The longer edge of the trapezoid was reported in front 76 ± 2% of trials (“windsurfer effect”) whether it was on the left or on the right. When the display was rotated 90°to produce a runway configuration, there was a striking asymmetry: the long edge was perceived to be in front 97% when it was on the bottom but only 43% when it was on top (“runway effect”). The runway effect persisted when the head was tilted 90° or when displays on the ceiling were viewed from the floor. Ninety-five percent of the variance of the variance in the strikingly different 3D perceptions produced by the same 2D trapezoid image was quantitatively explained by a model that assumes there are just three additive bias factors that account for perceiving an edge as closer: Implicit linear perspective, lower position on the retina (based on an automatic assumption of viewing from above), and being lower in world coordinates. PMID:26029073

  18. The Joint Winter Runway Friction Measurement Program: NASA Perspective

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1996-01-01

    Some background information is given together with the scope and objectives of the 5-year, Joint National Aeronautics & Space Administration (NASA)/Transport Canada (TC)/Federal Aviation Administration (FAA) Winter Runway Friction Measurement Program. The range of the test equipment, the selected test sites and a tentative test program schedule are described. NASA considers the success of this program critical in terms of insuring adequate ground handling performance capability in adverse weather conditions for future aircraft being designed and developed as well as improving the safety of current aircraft ground operations.

  19. 32 CFR 256.6 - Runway classification by aircraft type.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... type. Class A runways S-2, VC-6, C-1, C-2, TC-4C, U-10, U-11, LU-16, TU-16, HU-16, C-7, C-8, C-12, C-47, C-117, U-21, QU-22, E-1, E-2, O-1, U-1, U-3, U-6, U-8, U-9, O-2, OV-1, OV-10, T-28, T-34, T-41, T-42...-130, A-7, A-38, AV-8, P-2, P-3, T-29, T-33, T-37, T-39, T-1, HC-130B, C-131, C-140, C-5A, KC-97,...

  20. Developing an Innovative Field Expedient Fracture Toughness Testing Protocol for Concrete Materials

    SciTech Connect

    Wang, Jy-An John; Liu, Ken C; Naus, Dan J

    2008-09-01

    The Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to determine the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45 pitch. KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments. Application of the method to metallic, ceramic, and graphite materials has been demonstrated. One important characteristic of SNTT is that neither a fatigue precrack or a deep notch are required for the evaluation of brittle materials, which significantly reduces the sample size requirement. In this paper we report results for a Portland cement-based mortar to demonstrate applicability of the SNTT method to cementitious materials. The estimated KIC of the tested mortar samples with compressive strength of 34.45 MPa was found to be 0.19 MPa m.

  1. Innovative hyperspectral imaging (HSI) based techniques applied to end-of-life concrete drill core characterization for optimal dismantling and materials recovery

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Picone, Nicoletta; Serranti, Silvia

    2015-02-01

    The reduction of EOL concrete disposal in landfills, together with a lower exploitation of primary raw materials, generates a strong interest to develop, set-up and apply innovative technologies to maximize Construction and Demolition Waste (C&DW) conversion into useful secondary raw materials. Such a goal can be reached starting from a punctual in-situ efficient characterization of the objects to dismantle in order to develop demolition actions aimed to set up innovative mechanical-physical processes to recover the different materials and products to recycle. In this paper an innovative recycling-oriented characterization strategy based on HyperSpectral Imaging (HSI) is described in order to identify aggregates and mortar in drill core samples from end-of-life concrete. To reach this goal, concrete drill cores from a demolition site were systematically investigated by HSI in the short wave infrared field (1000-2500 nm). Results obtained by the adoption of the HSI approach showed as this technology can be successfully applied to analyze quality and characteristics of C&DW before dismantling and as final product to reutilise after demolition-milling-classification actions. The proposed technique and the related recognition logics, through the spectral signature detection of finite physical domains (i.e. concrete slice and/or particle) of different nature and composition, allows; i) to develop characterization procedures able to quantitatively assess end-of-life concrete compositional/textural characteristics and ii) to set up innovative sorting strategies to qualify the different materials constituting drill core samples.

  2. STS-68 on Runway with 747 SCA - Columbia Ferry Flyby

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor's landing 12 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the

  3. Graphical User Interface Development and Design to Support Airport Runway Configuration Management

    NASA Technical Reports Server (NTRS)

    Jones, Debra G.; Lenox, Michelle; Onal, Emrah; Latorella, Kara A.; Lohr, Gary W.; Le Vie, Lisa

    2015-01-01

    The objective of this effort was to develop a graphical user interface (GUI) for the National Aeronautics and Space Administration's (NASA) System Oriented Runway Management (SORM) decision support tool to support runway management. This tool is expected to be used by traffic flow managers and supervisors in the Airport Traffic Control Tower (ATCT) and Terminal Radar Approach Control (TRACON) facilities.

  4. 76 FR 21938 - Potential Environmental Impacts of the Proposed Runway 13 Extension and Associated Actions for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... Federal Aviation Administration Potential Environmental Impacts of the Proposed Runway 13 Extension and... Administration (FAA), Department of Transportation (DOT). ACTION: Notice of availability of a final EA and FONSI/ROD for the evaluation of the potential environmental impacts associated with the proposed Runway...

  5. Concrete density estimation by rebound hammer method

    NASA Astrophysics Data System (ADS)

    Ismail, Mohamad Pauzi bin; Jefri, Muhamad Hafizie Bin; Abdullah, Mahadzir Bin; Masenwat, Noor Azreen bin; Sani, Suhairy bin; Mohd, Shukri; Isa, Nasharuddin bin; Mahmud, Mohamad Haniza bin

    2016-01-01

    Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X- and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containing crushed granite.

  6. The Concrete and Pavement Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  7. Comparison of Procedures for Dual and Triple Closely Spaced Parallel Runways

    NASA Technical Reports Server (NTRS)

    Verma, Savita; Ballinger, Deborah; Subramanian Shobana; Kozon, Thomas

    2012-01-01

    A human-in-the-loop high fidelity flight simulation experiment was conducted, which investigated and compared breakout procedures for Very Closely Spaced Parallel Approaches (VCSPA) with two and three runways. To understand the feasibility, usability and human factors of two and three runway VCSPA, data were collected and analyzed on the dependent variables of breakout cross track error and pilot workload. Independent variables included number of runways, cause of breakout and location of breakout. Results indicated larger cross track error and higher workload using three runways as compared to 2-runway operations. Significant interaction effects involving breakout cause and breakout location were also observed. Across all conditions, cross track error values showed high levels of breakout trajectory accuracy and pilot workload remained manageable. Results suggest possible avenues of future adaptation for adopting these procedures (e.g., pilot training), while also showing potential promise of the concept.

  8. Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

    PubMed

    Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

    2003-01-01

    The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters. PMID:14522190

  9. Exploration of the Theoretical Physical Capacity of the John F. Kennedy International Airport Runway System

    NASA Technical Reports Server (NTRS)

    Neitzke, Kurt W.; Guerreiro, Nelson M.

    2014-01-01

    A design study was completed to explore the theoretical physical capacity (TPC) of the John F. Kennedy International Airport (KJFK) runway system for a northflow configuration assuming impedance-free (to throughput) air traffic control functionality. Individual runways were modeled using an agent-based, airspace simulation tool, the Airspace Concept Evaluation System (ACES), with all runways conducting both departures and arrivals on a first-come first-served (FCFS) scheduling basis. A realistic future flight schedule was expanded to 3.5 times the traffic level of a selected baseline day, September 26, 2006, to provide a steady overdemand state for KJFK runways. Rules constraining departure and arrival operations were defined to reflect physical limits beyond which safe operations could no longer be assumed. Safety buffers to account for all sources of operational variability were not included in the TPC estimate. Visual approaches were assumed for all arrivals to minimize inter-arrival spacing. Parallel runway operations were assumed to be independent based on lateral spacing distances. Resulting time intervals between successive airport operations were primarily constrained by same-runway and then by intersecting-runway spacing requirements. The resulting physical runway capacity approximates a theoretical limit that cannot be exceeded without modifying runway interaction assumptions. Comparison with current KJFK operational limits for a north-flow runway configuration indicates a substantial throughput gap of approximately 48%. This gap may be further analyzed to determine which part may be feasibly bridged through the deployment of advanced systems and procedures, and which part cannot, because it is either impossible or not cost-effective to control. Advanced systems for bridging the throughput gap may be conceptualized and simulated using this same experimental setup to estimate the level of gap closure achieved.

  10. Performance of Waterless Concrete

    NASA Technical Reports Server (NTRS)

    Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

    2010-01-01

    The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

  11. Measurement of tritium penetration through concrete material covered by various paints coating

    SciTech Connect

    Edao, Y.; Kawamura, Y.; Kurata, R.; Hayashi, T.; Yamanishi, T.; Fukada, S.; Takeishi, T.

    2015-03-15

    The present study aims at obtaining fundamental data on tritium migration in porous materials, which include soaking effect, interaction between tritium and cement paste coated with paints and transient tritium sorption in porous cement. The amounts of tritium penetrated into or released from cement paste with epoxy and urethane paint coatings were measured. The tritium penetration amounts were increased with the HTO (tritiated water) exposure time. Time to achieve a saturated value of tritium sorption was more than 60 days for cement paste coated with epoxy paint and with urethane paint, while that for cement paste without any paint coating took 2 days to achieve it. The effect of tritium permeation reduction by the epoxy paint was higher than that of the urethane. Although their paint coatings were effective for reduction of tritium penetration through the cement paste which was exposed to HTO for a short period, it was found that the amount of tritium trapped in the paints became large for a long period. Tritium penetration rates were estimated by an analysis of one-dimensional diffusion in the axial direction of a thickness of a sample. Obtained data were helpful for evaluation of tritium contamination and decontamination. (authors)

  12. Refractory concretes

    DOEpatents

    Holcombe, Jr., Cressie E.

    1979-01-01

    Novel concrete compositions comprise particles of aggregate material embedded in a cement matrix, said cement matrix produced by contacting an oxide selected from the group of Y.sub.2 O.sub.3, La.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Eu.sub.2 O.sub.3 and Gd.sub.2 O.sub.3 with an aqueous solution of a salt selected from the group of NH.sub.4 NO.sub.3, NH.sub.4 Cl, YCl.sub.3 and Mg(NO.sub.3).sub.2 to form a fluid mixture; and allowing the fluid mixture to harden.

  13. Effects of fertilizer and pesticides on concrete

    SciTech Connect

    Broder, M.F.; Nguyen, D.T.; Harner, A.L.

    1994-12-31

    Concrete is the most common material of construction for secondary containment of fertilizers and pesticides because of its relative low cost and structural properties. Concrete, however, is porous to some products it is designed to contain and is subject to corrosion. In this paper, concrete deterioration mechanisms and corrosion resistant concrete formulation are discussed, as well as exposure tests of various concrete mixes to some common liquid fertilizers and herbicides.

  14. Remote sensing over North Merritt Island. [space shuttle runway

    NASA Technical Reports Server (NTRS)

    Poonai, P. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. For monitoring the surface environment of North Merritt Island, two methods are studied, namely, color infrared photography and machine processing of LANDSAT multispectral scanner data. C.I.R. photos made at a height of about 12,000 ft were found to define the borders of ground features around the space shuttle runway with a nonsignificant mean error of 0.138 meters but a wide range, which can be reduced with photos taken at about 6,000 ft. LANDSAT multispectral scanner data, transformed by use of the function f(g) = g1 + g2 -g3 -g4 where g1, g2, g3, and g4 represent reflectance or grey levels of multispectral channels 1,2,3, and 4, gave values which are classifiable into a relatively small number of categories.

  15. KSC off-runway contingency operation - Mode 7

    NASA Technical Reports Server (NTRS)

    Maples, Arthur; Doerr, Donald

    1991-01-01

    The possibility of a mishap during a space shuttle landing at Kennedy Space Center (KSC) dictates the need for plans to rescue astronauts from areas other than the Shuttle Landing Facility (SLF). All shuttle landings are unpowered, gliding flight maneuvers, and a deviation from the planned flight profile could result in a shuttle landing or crashing somewhere other than the SLF runway. The geography of the Kennedy Space Center makes helicopter airlifting the only universal means of transportation for the rescue crew. This rescue crew is composed of KSC contractor fire-rescuemen who would ride to the crash scene on USAF HH-3 helicopters. These crews are provided with personal protective suits and training in shallow water, swamp, and dry land rescues. They aid the egress of the crew to a safe area for helicopter pickup and subsequent triage and medevac.

  16. Incorporating Active Runway Crossings in Airport Departure Scheduling

    NASA Technical Reports Server (NTRS)

    Gupta, Gautam; Malik, Waqar; Jung, Yoon C.

    2010-01-01

    A mixed integer linear program is presented for deterministically scheduling departure and ar rival aircraft at airport runways. This method addresses different schemes of managing the departure queuing area by treating it as first-in-first-out queues or as a simple par king area where any available aircraft can take-off ir respective of its relative sequence with others. In addition, this method explicitly considers separation criteria between successive aircraft and also incorporates an optional prioritization scheme using time windows. Multiple objectives pertaining to throughput and system delay are used independently. Results indicate improvement over a basic first-come-first-serve rule in both system delay and throughput. Minimizing system delay results in small deviations from optimal throughput, whereas minimizing throughput results in large deviations in system delay. Enhancements for computational efficiency are also presented in the form of reformulating certain constraints and defining additional inequalities for better bounds.

  17. NASA Runway Incursion Prevention System (RIPS) Dallas-Fort Worth Demonstration Performance Analysis

    NASA Technical Reports Server (NTRS)

    Cassell, Rick; Evers, Carl; Esche, Jeff; Sleep, Benjamin; Jones, Denise R. (Technical Monitor)

    2002-01-01

    NASA's Aviation Safety Program Synthetic Vision System project conducted a Runway Incursion Prevention System (RIPS) flight test at the Dallas-Fort Worth International Airport in October 2000. The RIPS research system includes advanced displays, airport surveillance system, data links, positioning system, and alerting algorithms to provide pilots with enhanced situational awareness, supplemental guidance cues, a real-time display of traffic information, and warnings of runway incursions. This report describes the aircraft and ground based runway incursion alerting systems and traffic positioning systems (Automatic Dependent Surveillance - Broadcast (ADS-B) and Traffic Information Service - Broadcast (TIS-B)). A performance analysis of these systems is also presented.

  18. Wake Encounter Analysis for a Closely Spaced Parallel Runway Paired Approach Simulation

    NASA Technical Reports Server (NTRS)

    Mckissick,Burnell T.; Rico-Cusi, Fernando J.; Murdoch, Jennifer; Oseguera-Lohr, Rosa M.; Stough, Harry P, III; O'Connor, Cornelius J.; Syed, Hazari I.

    2009-01-01

    A Monte Carlo simulation of simultaneous approaches performed by two transport category aircraft from the final approach fix to a pair of closely spaced parallel runways was conducted to explore the aft boundary of the safe zone in which separation assurance and wake avoidance are provided. The simulation included variations in runway centerline separation, initial longitudinal spacing of the aircraft, crosswind speed, and aircraft speed during the approach. The data from the simulation showed that the majority of the wake encounters occurred near or over the runway and the aft boundaries of the safe zones were identified for all simulation conditions.

  19. Prolong the life of concrete

    SciTech Connect

    Ilaria, J.E.

    1995-07-01

    The most widely used construction materials are concrete and related cement-based products, such as common building block. The excellent reputation of concrete as a durable material of construction has been questioned i modern times. The expanded use of Portland cement concrete, the increase in corrosive environments, and lack of understanding of the composition of concrete all indicate a need for methods to increase life expectancy. Chemical and mechanical factors can shorten service life. Understanding these properties will lead to the proper application of protective coatings.

  20. STS-68 on Runway with 747 SCA - Columbia Ferry Flyby

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor's landing 12 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the

  1. Concrete production floating platforms

    SciTech Connect

    Letourneur, O.; Falcimaigne, J.

    1981-01-01

    The floating production platforms operating in the North Sea are adapted from drilling semisubmersibles which allow only a limited payload capacity. Experience of concrete production platforms constructed for the North Sea has led Sea Tank Co. to propose a floating platform which offers large payload and oil storage capacities similar to those of existing fixed platforms. Sea Tank Co. and Institut Francais du Petrole joined forces in early 1976 to study the feasibility of a concrete floating production platform incorporating the structure and the production riser together. The results of this 3-yr program show that the concrete floating structure is economically attractive for permanent utilization on a production site. Furthermore, concrete has definite advantages over other materials, in its long term behavior.

  2. Effects of various runway lighting parameters upon the relation between runway visual range and visual range of centerline and edge lights in fog

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1973-01-01

    Thirty six students and 54 commercial airline pilots were tested in the fog chamber to determine the effect of runway edge and centerline light intensity and spacing, fog density, ambient luminance level, and lateral and vertical offset distance of the subject from the runway's centerline upon horizontal visual range. These data were obtained to evaluate the adequacy of a balanced lighting system to provide maximum visual range in fog viewing both centerline and runway edge lights. The daytime system was compared against two other candidate lighting systems; the nighttime system was compared against other candidate lighting systems. The second objective was to determine if visual range is affected by lights between the subject and the farthestmost light visible through the fog. The third objective was to determine if college student subjects differ from commercial airline pilots in their horizontal visual range through fog. Two studies were conducted.

  3. 31. CRANE RUNWAY FOR 5TON PUSH TYPE CRANE, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. CRANE RUNWAY FOR 5-TON PUSH TYPE CRANE, SANTA ANA RIVER NO. 3, SEPT. 4, 1945. SCE drawing no. 523856-2. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

  4. Three-track runway and taxiway profiles measured at international airports I and J

    NASA Technical Reports Server (NTRS)

    Hall, A. W.

    1972-01-01

    Three-track runway and taxiway profiles are presented for use in studies of airplane response to ground roughness. Tabulated and plotted data for two international airports, (designated I and J), are included.

  5. Three-track runway and taxiway profiles measured at international airports G and H

    NASA Technical Reports Server (NTRS)

    Hall, A. W.

    1972-01-01

    Three-track runway and taxiway profiles are presented for use in studies of airplane response to ground roughness. This report presents the tabulated and plotted data for two international airports (designated airports G and H).

  6. Three-track runway and taxiway profiles measured at International Airports E and F

    NASA Technical Reports Server (NTRS)

    Hall, A. W.

    1971-01-01

    Three-track runway and taxiway profiles are presented for use in studies of airplane response to ground roughness. This report presents the tabulated and plotted data for two international airports (designed airports E and F).

  7. White Sands Space Harbor Area 1, Runway 17/35, Extending 35,000 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    White Sands Space Harbor Area 1, Runway 17/35, Extending 35,000 feet north from Range Road 10, beginning approximately 4.2 miles northeast of intersection with Range Road 7, White Sands, Dona Ana County, NM

  8. Development and Execution of the RUNSAFE Runway Safety Bayesian Belief Network Model

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.

    2015-01-01

    One focus area of the National Aeronautics and Space Administration (NASA) is to improve aviation safety. Runway safety is one such thrust of investigation and research. The two primary components of this runway safety research are in runway incursion (RI) and runway excursion (RE) events. These are adverse ground-based aviation incidents that endanger crew, passengers, aircraft and perhaps other nearby people or property. A runway incursion is the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take-off of aircraft; one class of RI events simultaneously involves two aircraft, such as one aircraft incorrectly landing on a runway while another aircraft is taking off from the same runway. A runway excursion is an incident involving only a single aircraft defined as a veer-off or overrun off the runway surface. Within the scope of this effort at NASA Langley Research Center (LaRC), generic RI, RE and combined (RI plus RE, or RUNSAFE) event models have each been developed and implemented as a Bayesian Belief Network (BBN). Descriptions of runway safety issues from the literature searches have been used to develop the BBN models. Numerous considerations surrounding the process of developing the event models have been documented in this report. The event models were then thoroughly reviewed by a Subject Matter Expert (SME) panel through multiple knowledge elicitation sessions. Numerous improvements to the model structure (definitions, node names, node states and the connecting link topology) were made by the SME panel. Sample executions of the final RUNSAFE model have been presented herein for baseline and worst-case scenarios. Finally, a parameter sensitivity analysis for a given scenario was performed to show the risk drivers. The NASA and LaRC research in runway safety event modeling through the use of BBN technology is important for several reasons. These include: 1) providing a means to clearly

  9. Marine concrete

    SciTech Connect

    Marshall, A.L.

    1990-01-01

    This book examines how the chemical and physical properties of the oceans affect the durability, fatigue, and corrosion of structures. Structure types addressed include oil platforms, arctic structures, and sea walls. Reviews qualities of plain, reinforced, prestressed, and floating concrete. Discusses the inspection, maintenance, and repair of concrete structures.

  10. Determination of optimal trajectories for an aircraft returning to the runway following a complete loss of thrust after takeoff

    NASA Astrophysics Data System (ADS)

    Gordon, Craig A.

    This thesis examines the ability of a small, single-engine airplane to return to the runway following an engine failure shortly after takeoff. Two sets of trajectories are examined. One set of trajectories has the airplane fly a straight climb on the runway heading until engine failure. The other set of trajectories has the airplane perform a 90° turn at an altitude of 500 feet and continue until engine failure. Various combinations of wind speed, wind direction, and engine failure times are examined. The runway length required to complete the entire flight from the beginning of the takeoff roll to wheels stop following the return to the runway after engine failure is calculated for each case. The optimal trajectories following engine failure consist of three distinct segments: a turn back toward the runway using a large bank angle and angle of attack; a straight glide; and a reversal turn to align the airplane with the runway. The 90° turn results in much shorter required runway lengths at lower headwind speeds. At higher headwind speeds, both sets of trajectories are limited by the length of runway required for the landing rollout, but the straight climb cases generally require a lower angle of attack to complete the flight. The glide back to the runway is performed at an airspeed below the best glide speed of the airplane due to the need to conserve potential energy after the completion of the turn back toward the runway. The results are highly dependent on the rate of climb of the airplane during powered flight. The results of this study can aid the pilot in determining whether or not a return to the runway could be performed in the event of an engine failure given the specific wind conditions and runway length at the time of takeoff. The results can also guide the pilot in determining the takeoff profile that would offer the greatest advantage in returning to the runway.