Abstract:
This report documents the moldeling strategy and associated verification which permits analysis of multiple PCC plain jointed slabs. Several subbase/soil layers below the slabs and separation of the slab and base layer are considered. Load effects include those associated with both multiple tire and linear temperature gradients. A technique for modeling aggregate interlock shear transfer across PCC pavement joints is developed and verified. The overall development is contained in the computer program EverFE. The computer program uses a graphical user interface which aids its use.

Authors:
Davids,W. G., Turkiyyah,G. M., Mahoney,J. P.

Keywords:
aggregate, aggregate interlock, analysis, base, computer, computer program, developed, development, EverFE, finite element, Finite elements, ITS, Joints, joints load transfer, modeling, pavement, pavements, PCC, permits, program, rigid pavement, temperature, tire

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Abstract:
This report documents the construction of two experimental test sections of asphalt concrete pavement containing polymer and ground rubber additives. The two sections are located on I-5 south of Olympia, Washington and were constructed in the summer of 1992.The test sections were paved with an open-graded using PBA-6 and asphalt cement binders. PBA-6 is a performance based asphalt cement with a polymer additive. is a performance based asphalt cement but with ground tires as the additive. The is a for a new product developed by the U.S. Oil and Refining Company of Tacoma, Washington. The completed test sections are performing well, although the PBA-6GR section is flushing due to too high of an initial asphalt content. The sections will be monitored of 10 years to determine long-term performance.

Authors:
Livingston,J., Anderson,K. W.

Keywords:
additive, asphalt, asphalt concrete, Asphalt Concrete pavement, Asphalt content, asphalt pavement, concrete, construction, counties, crumb-rubber, developed, experimental, line, open-graded, pavement, pavements, performance, performance based specifications, polymer, rubber, tire, tires, Washington

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Abstract:
This study investigated the noise produced by a single passenger vehicle tire heard at the roadside. This report presents the study's equipment and the development of the data reduction techniques. To choose test sites, selection criteria were applied that would provide extraneous artifacts from influencing the results of the study. Special care was taken to minimize microphone wind noise caused by the high speed turbulent flow of the measurement process. Measurements were taken on both old and new Class B asphalt, Class D asphalt, and portland cement concrete pavement. The results are presented in graphical form. The results indicated that the Class D asphalt surfaces measured in this study did not produce lower roadside noise, and these surfaces were no more acoustically absorbent than the other road surfaces.

Authors:
Chalupnik,J. D., Anderson,D.

Keywords:
noise, traffic noise, tire noise, roadway noise, tire, surface interaction

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Abstract:
Noise mitigation strategies involving both noise reduction at the source of transportation noise and at the receiver of transportation noise are reviewed. The following major sources of noise within a motor vehicle considered: engine, intake, exhaust, cooling fan, transmission, and tire noise. Current research intended to address methods of reducing noise far each of these sources is discussed. It was found that vehicle manufacturer efforts in the U.S. to reduce vehicle noise is currently being motivated marketplace for quiet vehicles. In addition to the potentialnoise reduction from specific components of the vehicle, it was found that the type of roadway pavement can have a significant effect on noise. A key strategy for reducing transportation noise at the receiver of the noise is land use compatibility planning. local agencies who have successfully implemented and use compatibility planning programs were interviewed. These programs fall into two broad The first category is land use compatibility brought about by zoning. this category, land uses that are inherently with transportation noise sources are adjacent to the sources. The second category, referred to as proponent mi involves a process of mitigation needed to make the use with transportation noise through mitigation efforts funded by the proponent of the development. It was found that noise and land use compatibility programs were most beneficial to communities in the earlier stages of development whereas the use of a local noise ordinance was found to be more beneficial to communities that are more fully developed.

Authors:
Herman,L. A., Bowlby,W.

Keywords:
agencies, developed, development, land use, land use compatibility, land-use, methods, mitigation, noise, noise abatement, noise barriers, noise reduction, pavement, planning, program, research, roadway, tire, tire noise, traffic noise, transportation, vehicle noise, zoning

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Abstract:
Noise mitigation strategies involving both noise reduction at the source of transportation noise at the receiver of transportation noise are reviewed. The following major sources of noise within a motor vehicle were considered: engine, intake, exhaust, cooling fan, transmission, and tire noise. Current research intended to address methods of reducing noise far each of these sources is discussed. It was found that vehicle manufacturer efforts in the U.S. to reduce vehicle noise is currently being motivated marketplace for quiet vehicles. In addition to the potential noise reduction from specific components of the vehicle, it was found that the type of roadway pavement can have a significant effect on noise. A key strategy for reducing transportation noise at the receiver of the noise is land use compatibility planning. Local agencies who have successfully implemented and use compatibility planning programs were interviewed. These programs fall into two broad categories. The first category is land use compatibility brought about by zoning. In this category, land uses that are inherently with transportation noise sources are adjacent to the sources. The second category, referred to as proponent mitigation, involves a process of mitigation needed to make the use with transportation noise through mitigation efforts funded by the proponent of the development. It was found that noise and land use compatibility programs were most beneficial to communities in the earlier stages of development whereas the use of a local noise ordinance was found to be more beneficial to communities that are more fully developed.

Authors:
Herman,L. A., Bowlby,W.

Keywords:
agencies, developed, development, land use, land use compatibility, land-use, methods, mitigation, noise, noise abatement, noise barriers, noise reduction, pavement, planning, program, research, roadway, tire, tire noise, traffic noise, transportation, vehicle noise, zoning

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Abstract:
The major objectives of this study were to examine: (1) the types of recycled materials that are appropriate and feasible as alternative paving materials such as glass and tires; and (2) the types of recycled materials, such as mixed-plastics and compost, that can be utilized in all types of transportation applications other than pavements. Seven key products are investigated: tires; glass; asphalt concrete fly ash; compost; mixed plastics; and sign stock. Performance and cost data for pavements is documented for both in-state and nationwide applications. The national experience \'with the use of waste glass as an additive to asphalt concrete and its use in unbound base material is so highlighted. Programs for experimental use of recycled material are outlined. Recommendations for staffing and program changes to deal with recycling are also discussed.

Authors:
Swearigen,D. L., Jackson,N. C.

Keywords:
additive, Alternative, applications, asphalt, asphalt concrete, base, base materials, concrete, construction, cost, data, experimental, fly ash, Glasphalt, highway, highway construction, ITS, materials, objectives, pavement, pavements, performance, program, recycled ACP, recycling, Rubber-asphalt, tire, tires, transportation

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Abstract:
This is the final report of a study of the way in which tire/road noise changes as the pavement ages and wears. Measurements of the levels of noise generated at the tire/road-surface interface were made on sections of a variety of asphaltic and concrete compositions ranging in age from newly laid to 29 years. Data from these measurements are presented in graphical form showing levels and trends of levels with time. While measurements made in this study do not portray the noise levels at the roadside, they do rank order the source noise levels of the various surfaces devoid of the noise absorption characteristics of the surface. An interpretation of the data is provided to assist highway planners, designers, or environmental engineers. As an add-on to the main study, a comparison of the noise from studded tires and non-studded tires of the same tread design was made for a variety of roadway surface types.

Authors:
Chalupnik,J. D., Anderson,D.

Keywords:
traffic noise, noise, tire noise, tire, road noise, noise measurements, trailers, roadway aging, roadway wear, studded tires

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Abstract:
This project studies the ways is which tire noise changes as the pavement on which they run ages and wears. Initial measurements of the levels and spectral distribution of noise generated at the tire-road surface interface have been made on a number of road surfaces of a variety of asphaltic and concrete compositions. In all, noise characteristics from thirty-one road-way sections are under biannual study. All of these sections were freshly completed within six months of the initiation of the study. Data from the first four biannual sessions are presented in graphical form.

Authors:
Chalupnik,J. D., Anderson,D.

Keywords:
environmental, tire noise, tire, road noise, roadway noise, roadway aging

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Abstract:
This report describes a survey of current practice as well as analysis performed to develop guidelines for agencies which need load restrictions during spring thaw periods. The results show for a range of locations in the US and Canada that the average load restriction applied is about 44 percent. The analysis performed in the study tends to confirm that level of load restriction. Further, it was found for the assumed conditions that a minimum load restriction(if any load restriction is needed) is about 20 percent. Load restrictions greater than 60 percent are generally not warranted for the range of cases studied. An air temperature based criterion (Thawing index) was developed which can be used to estimate when to apply and remove load restrictions.

Authors:
Mahoney,J. P., Rutherford,G. S., Hicks,R. G., Rwebangira,T.

Keywords:
pavement management, load restrictions, frost, thaw, tire, axle, spring thaw, thaw weakening, research

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Abstract:
This report describes a survey of current practice as well as analysis performed to develop guidelines for agencies which need load restrictions during spring thaw periods. The results show for a range of locations in the US and Canada that the average load restriction applied is about 44 percent. The analysis performed in the study tends to confirm that level of load restriction. Further, it was found for the assumed conditions that a minimum load restriction(if any load restriction is needed) is about 20 percent. Load restrictions greater than 60 percent are generally not warranted for the range of cases studied. An air temperature based criterion (Thawing index) was developed which can be used to estimate when to apply and remove load restrictions.

Authors:
Mahoney,J. P.

Keywords:
pavement management, load restrictions, frost, thaw, tire, axle, spring thaw, thaw weakening

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Abstract:
This report describes the techniques used to evaluate the effects of various axle configurations with dual and single tires on pavement performance and the current State of Washington Regulation RCW 46.44.042. Equivalent wheel load factors were developed for various widths of single tires on both rigid and flexible pavements. Single tires with widths 10 to 18 inches were analyzed and it was found that by equivalent axle loads the predicted damage to pavements was greater for axles with single tires that those with dual tires. To verify the theoretical analyses, two field experiments were conducted. First, extensometers were placed in the outer wheel path of the pavement ramp at the Fife I-5 weigh station. Truck induced pavement surface deflections were measured after the vehicles were weighed on the scale. A comparison of measured and calculated deflections revealed good agreement thus in part verifying the theoretically based calculations. Second, a field site near Edmondton, Alberta was also used in the verification process by use of the WSDOT Falling Weight Deflectometer. Again the theoretical approach was further verified.

Authors:
Mahoney,J. P., Sharma,J.

Keywords:
pavement management, transport, weight, evaluation, regulation, tire

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Abstract:
The project goal was to evaluate different methods of cutting recessed skip stripe grooves, and to evaluate various pavement marking materials placed into the recesses. The project objective was to find a marking system for our mountain pass highways that would tolerate snowplowing and sanding operations, studded tires, and chain wear.Three methods of pavement grooving and three types of making material were evaluated over a four-year period. The grooving methods were evaluated with regard to production rate, the quality of the finished groove, and cost. The marking materials were checked for ease of installation, cost durability, and visibility.Only one method of grooving was found that produced the desired recess shape at a reasonable cost and in a timely manner. All three of the making materials were durable enough to survive for three years, but none produced the desired wet-daytime or wet-night visibility needed for adequate lane delineation. This loss of visibility under wet conditions was due to the lack of retroreflectance from the marking materials.

Authors:
Anderson,K. W.

Keywords:
chains, condition, cost, delineation, durability, grooves, grooving, highway, highway delineation, Highways, lane lines, materials, methods, night visibility, pavement, project, quality, rainfall, retroreflectance, snowplows, striping, studded tire, studded tires, System, tire, tires, Traffic markings

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Abstract:
Evaluation of pavement patching materials was accomplished by simulating potholes in the surface, repairing the holes and subjecting them to traffic loadings. Loadings were applied utilizing the Pavement Test Facility, which applies truck simultaneously. Measurements of strength resulted in a comparative evaluation. tires was determined. Tire and various passenger car tire .types s skidding potential and pavement performance. Tread wear and protrusion of studs in the tires was determined.

Authors:
Cook,John C.

Keywords:
evaluation, facilities, materials, pavement, Pavement Patching Material, Polishing, Skidding Potential, Studded Tires, Garnet Impregnated Tires, pavement performance, performance, strength, studs, test track, tire, tires, traffic, truck

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Abstract:
There are indications that many trucks now have front axle loads approaching the maximum allowable for single axles which increases the potential for pavement damage. This report is intended to be a State-Of-The-Art approach to answer several pertinent questions from a theoretical study based on hypothetical pavements and loads, but based on reasonable material characteristics and pavement behavior from previous research. The results are a series of relationships based on pavement life which can be used to determine any number of "equivalencies." These equivalencies can be used to compare the destructive effects of various sizes of single and dual tires, axle loads , pavement thicknesses , speed and temperatures. The general nature of this report provides a wide range of conditions for comparison.on a relative basis.

Authors:
Terrel,R., Rimsritong,S.

Keywords:
asphalt pavement, axle, behavior, condition, damage, dual tires, equivalencies, loads, pavement, pavement damage, pavement life, pavements, research, single axle, speed, speed and temperature, state-of-the-art, temperature, tire, tire contact pressure, tires, truck, trucks, wheel load

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Abstract:
This study was conducted to collect data on the operational characteristics of highway, snow, and studded snow tires and other winter traction aids. The objective of the study was to perform various vehicle maneuvers to evaluate the tire characteristics on wet and dry pavement surfaces. Tests took place on the Washington State Patrol Driver Training Course at Sanderson Field, located west of Shelton, Washington. The testing was done with the cooperation of the Washington State Patrol who furnished personnel and equipment to assist in this research effort.This test maneuvers evaluated during the study are as follows:Test No. 1 Maneuvering (Serpentine Course)Test No. 2 Hairpin CurveTest No. 3 High Speed Lane ChangeTest No. 4 Locked-Wheel StopIn addition to the three types described above, other new traction type products and tires were evaluated. These consisted of studded snow tires with "Norfin" studs, and Garnet impregnated snow tires. Studded tires on all four wheels were also evaluated, at the request of the Washington State Patrol. This combination is used by Troopers assigned to mountain highway passes and areas where there is a large buildup of snow and ice during the winter. This report consists of two areas of evaluation. One involves tire combinations (front and rear) and the other is the evaluation of individual tire types. In addition to these two areas, a separate section is devoted to the tire and vehicle characteristics of Washington State Patrol's vehicle when compared with a Department of Highway's Motor Pool Vehicle. Included also is the test vehicles' description.

Authors:
Toney,Carl A.

Keywords:
data, equipment, evaluation, highway, No Keywords found in report, pavement, pavement surface, research, snow, speed, studded tire, studded tires, studs, tests, tire, tires, traction, training, Washington, Washington state, winter

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Abstract:
This report presents results obtained from the analyses of data which were collected during the performance of Phase I and Phase of this project. The data were at the A. Riedesel Pavement Testing Facility which is operated by Washington State University and is located in Pullman, Washington. Regression analyses were formed in order to relate various factors to each other. The factors used in the analyses included stud type, stud protrusion, speed, air temperature, pavement temperature, environmental conditions, stud hardness and tread depth. The purpose was to evaluate the relative importance of these factors pavement wear. It was found that the type of overlay, the type of stud and the protrusion length were the most important factors affecting pavement wear under Test conditions. The other factors could not be sufficiently isolated to determine their relative importance. Average wear rates were calculated for the different types of pavements and by the different stud types. A formula was developed which can be used to calculate pavement life under certain conditions. The results obtained for Phase I and Phase were compared and the difference in these results is discussed. Some of the difference was due to the different between the two phases A comparison with other associated research was madeA striping paint study was made and the results are in this report.

Authors:
Sorensen,H.

Keywords:
condition, data, developed, environmental, facilities, overlay, pavement, Pavement Durability, life & performance, asphalt pavement, portland cement concretes, overlays, surface textures, studded tires, skid resistance, pavement life, pavement temperature, pavements, performance, project, regression, repair, research, speed, striping, striping paints, Studded, studded tire, Study, temperature, tire, Washington, Washington state

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Abstract:
This report presents some data obtained from testing twenty-two different types of overlays on three concentric tracks at the G.A. Riedesel Pavement Testing Facility at Washington State University. Six different passenger winter tires were tested, including unstudded, a garnet dust snow retread, and four different types of studs. The data represents a testing period from November 20, 1972 to February 20, 1973 and a total 300,000 revolutions, that is 900,000 wheel applications on the inside track and 300,000 wheel applications on the outside track.The results reveal that the different polymer, concretes show the least wear, and that rubber additives improved the performance of some of the asphalt concrete overlays. The type #2 stud continually showed less wear than the other types of studs. Comparisons with the previous ring reveals that the present ring overlays showed less wear, and that stud protrusions are much less. A comparison and discussion of the results from both rings a t this wheel application range is presented. The results from the present data are also discussed. The results are tentative and may change as the present test continues.

Authors:
Krukar,M., Cook,J. C.

Keywords:
applications, asphalt, asphalt concrete, concrete, concrete overlays, data, effects, facilities, Interim, overlay, overlays, pavement, Pavement overlays, performance, Phase II, polymer, rubber, snow, Studded, studded tire, studs, tire, tires, Washington, Washington state, winter

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Abstract:
Four different types of pavement marking materials were tested in Ring #6; three brands of striping paints and one thermoplastic stripping tape. These striping materials were applied on two sections, the ploymer ranked on the basis of appearance, wear, and whiteness.The thermoplastic striping material consistently outperformed the three paints. The materials wore more rapidly on the polymer cement concrete that on the asphalt concrete and the ranking order for the paints was different for the two sections. The Type #3 stud seemed to have worn the paints more rapidly than either #4, #2, GST, US and UST studs and tires in that order respectively. The superiority of the ethermoplastic striping tape was due to its thickness and its construction. Last year Kennametal, Inc. sent the Transportation Systems Section four different types of traffic paint and a thermoplastic striping tape. Time did not permit the testing of these materials in Ring #5, so these materials were tested in Ring # 6.

Authors:
Krukar,M.

Keywords:
asphalt, asphalt concrete, concrete, construction, effects, ITS, materials, pavement, Phase II, polymer, striping, striping paints, stripping, Studded, studded tire, studded tires, studs, System, systems, tire, tires, traffic, transportation

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Abstract:
This report presents results obtained from testing at the G. A. Riedesel Pavement Testing Facility at Washington State University during the period from February 11 to May 4, 1972. The purpose of this project was fourfold: 1) to determine pavement wear caused by studded tires ; 2) to evaluate the resistance of different pavement materials and textures used in the states of Washington and Idaho to wear caused by tire studs; 3) to test pavement materials and overlays to reduce tire stud damage; and, 4) to study the effect of studded truck tires on pavements. Ring #5 consisted of three concentric tracks on which 16 tires travelled in eight wheel paths. Three studded types and unstudded passenger tires , three studded and unstudded truck tires, and 46 sections of various types of pavement materials surface overlays and surface textures were tested. The results are based on wear in terms of rate of wear, area removed, maximum and average rut depth using the WSU Profilometer, and the camera wire shadow apparatus, and are valid only under WSU testing conditions. The findings indicate that some pavement materials are more resistant to the effect of studded tires than others. All types of studded tires tested caused some pavement wear and this affected the skid resistance values. The new types of studs reduced wear of various pavement materials. Studded truck tire wear was less than expected due to equipment problems.

Authors:
Krukar,M., Cook,J. C.

Keywords:
camera, condition, damage, equipment, facilities, materials, overlay, overlays, pavement, Pavement Durability, life & performance, asphalt pavement, portland cement concretes, overlays, surface textures, studded tires, skid resistance, pavements, project, repair, resistance, skid resistance, studded tire, studded tires, studs, Study, tire, tires, truck, Washington, Washington state

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Abstract:
This preliminary report presents data obtained from testing at the L A Riedesel Pavement Testing Facility during the period from February 11 t o May 4, 1972. The purpose of this project was four fold: (1) to determine pavement wear caused by studded tires; (2) to evaluate the resistance of different pavement materials and textures used in the states o f Washington and Idaho to wear caused by tire studs; (3) t o test pavement materials and overlays to reduce tire stud damage; and, (4) to study the effect of studded truck tires on pavements.This preliminary report presents data obtained from testing at the G. A. Riedesel Pavement Testing Facility, during the period from February 11 to May 4, 1972.

Authors:
Krukar,M., Cook,J. C.

Keywords:
damage, data, facilities, materials, overlay, overlays, pavement, Pavement Durability, life & performance, asphalt pavement, portland cement concretes, overlays, surface textures, studded tires, skid resistance, project, resistance, studded tire, studded tires, studs, Study, tire, tires, truck, Washington

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Abstract:
This report presents results obtained from testing at the A. Riedesel Pavement Testing Facility at Washington State University during the period of November 20, 1972 to May 1973. The purpose of this project was three-fold: (1 to determine pavement wear caused by studded tires; 2) to evaluate the resistance of different pavement overlays used in the states of Washington and Idaho to wear caused by studs; and 3) to test pavement materials and overlays to reduce tire stud damage. Ring and Phase of this project consisted of three concentric tracks on which 16 tires traveled in eight wheel paths. Four types of studs in passenger snow two types of passenger tires, and unstudded truck tires, and 22 sections of various types of pavement overlays and surfacings were tested. Four different stripes were also tested. The results are based on wear in terms of rate of wear, area removed, maximum and average rut depths using the WSU profilometer and the camera wire shadow box apparatus. Skid resistance values were measured using the California Skid Tester and the English Portable Skid Tester. The results are valid only under WSU testing conditions. The findings indicate that some pavement overlays are resistant to the effect of studded tires than others. All types of studded tires tested caused some pavement wear and this affected skid resistance values. Some of the newer types of studs reduced wear of various pavement overlays. The pavements having the most wear resistance had the skid resistance retention characteristics. Additives to asphalt skid resistance helped wear resistance characteristics but lowered skid resistance on characteristics.

Authors:
Krukar,M., Cook,J. C.

Keywords:
asphalt, California, camera, condition, damage, facilities, materials, overlay, overlays, pavement, Pavement Durability, life & performance, asphalt pavement, portland cement concretes, overlays, surface textures, studded tires, skid resistance, pavements, project, repair, resistance, skid resistance, snow, studded tire, studded tires, studs, tire, tires, truck, Washington, Washington state

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Abstract:
The purpose of this study was to investigate the acoustic effects of two topping materials used on bridges in the Seattle area. One material was applied to the bridge on Interstate-5 which crosses the Duwamish River. It is an English product called Sprag-Grip which is supposed to have very good anti-skid properties, as well as the ability to stick to the road in thin layers thus making it suitable for the repair of worn surfaces. The other material is an epoxy -asphalt mixture which was applied to some sections of the Evergreen Point Floating Bridge over Lake Washington, particularly over sections where worn grating was causing excessive noise. Hopefully, this substance will be capable of long-term sticking in relatively thin layers. Of the two materials, it was found that the epoxy-asphalt topping on the Evergreen Point Floating Bridge was by far the quieter, and, at least as newly applied, proved to be very quiet at the road/tire interface. It is likely that this good acoustic performance is due to the smoothness of the surface rather than directly to the fact that the material contains epoxy. The role of the epoxy would be as an adhesive and to resist wear so that its original acoustic performance could be maintained for a considerable length of time. Spray-Grip, on the other hand, although slightly quieter than the rutted, worn roadway, was not as quiet as the original unworn road surface. Experimental Procedures The primary contribution of a road surface to the noise 'radiating from a vehicle is in the noise emitted at the road/tire interface; therefore, the major thrust of this effort was directed toward measuring this effect. There also were some measurements of community noise levels before and after the resurfacing of the bridges. The tire noise tests were taken on the right rear wheel of a Laboratory station wagon upon which a new tire was mounted (a Pennsylvania Patrol Special, size 8. 55-15). (The tread design and depth of this tire are shown on page 2. ) This tire was mounted on a wheel and used on the vehicle only daring tests. Between tests it was stored so that unnecessary wear would not change its acoustic character-teristics. The noise pickup device was a specially baffled microphone located about 7 inches from the road/tire interface by a bracket holding it on the outside of the tire. One of the major problems in making noise measurements of this type is to have a microphone that will pick up only tire noise and be baffled from wind noise. This problem has been solved by a microphone baffling system especially designed by this Laboratory.

Authors:
Foss,Rene N.

Keywords:
asphalt, bridge, bridges, community noise, design, Epoxy, experimental, floating bridge, highway, ITS, materials, mixture, noise, Noise Levels, noise measurements, performance, repair, roadway, seattle, Study, System, tests, tire, tire noise, Washington, wind, Wind Noise

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Abstract:
Three different kinds of base material of varying base thicknesses were tested at the Washington State University Test Track on Ring #3 during the fall of 1967 and the spring of 1968. Twelve 18-foot test sections consisting of 4.5, 7.0, 9.5 and 12 inches of untreated crushed rock surfacing top course base; 3.0, 5.0, and 7.0 and 9.0 inches of emulsion treated crushed surfacing top course base; and 0.0, 2.0, 3.5 and 5.0 inches of special non-fractured screened aggregate asphalt treated base, covered by a uniform 3.0-inch thick Class "B" asphalt concrete wearing course were tested during this period. This pavement structure was built on a clay-silt subgrade soil.Instrumentation consisted of moisture tensiometers, strain gages, pressure cells, LVDT gages and thermocouples for measuring moisture, strain, stress, dynamic deflections and temperatures. Benkleman beam readings were taken.The testing period revealed that the fall failure modes were different from the spring failures. The fall failure patter started from transverse cracks in the thin sections which developed into alligator cracking patterns. These cracks appeared after a period of cold weather and heavy rains followed by a warming period. It seems that thermal and mechanical loads were responsible for the fall failures on the thin sections. The spring failures were very rapid and sudden and were due to environmental factors which led to saturated subgrade, thus resulting in poor bearing capacity. Punching shear was the failure mode. The thickest sections survived without cracks but developed severe rutting. Examination revealed that these ruts extended into the subgrade and that fatigue cracking was developing on the bottom of the bases.Comparison of the results with those obtained from Ring# 2, which was similar in base materials and thickness, show that they were similar in many respects. This indicates that the test track is capable of replicating results and is a reliable research instrument.Equivalencies were developed for the different materials. On this basis the special aggregate asphalt treated base was superior to the emulsion treated and untreated crushed rock bases in that order. These results were comparable to those obtained from test Ring #2.Maximum values for static and dynamic deflections, strains and stresses for different times and temperatures were developed. The lateral position of the dual tires with respect to the gage severely affected the strain, stresses and deflection values. Temperature also caused variations in the measurements. Spring instrument readings for static and dynamic deflections, strain and stress show increased values by as much as 2 to 4 times of those obtained in the fall. Spring subgrade conditions probably are responsible for these differences.Ring #3 series operational time was twice that of Ring #2 and sustained four times the wheel load applications. Construction and testing environmental conditions were superior to those for Ring #2 and hence contributed to the longer test period. This points out that environmental factors are very important in pavement life.

Authors:
Krukar,M.

Keywords:
aggregate, Alligator Cracking, applications, asphalt, asphalt concrete, base, base materials, bearing capacity, Benkleman beam, concrete, condition, construction, cracking, dual tires, environmental, experimental, fatigue, fatigue cracking, loads, materials, pavement, pavement life, pressure, pressure cell, rain, research, research at the WSU, strains, stresses, subgrade, temperature, test track, tire, tires, volume, Volume No.4, Washington, Washington state, wheel load

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Abstract:
Three different kinds of base material of varying base thicknesses were tested at the Washington State University Test Track on Ring #3 during the fall of 1967 and the spring of 1968. Twelve 18-foot test sections consisting of 4.5, 7.0, 9.5 and 12 inches of untreated crushed rock surfacing top course base; 3.0, 5.0, and 7.0 and 9.0 inches of emulsion treated crushed surfacing top course base; and 0.0, 2.0, 3.5 and 5.0 inches of special non-fractured screened aggregate asphalt treated base, covered by a uniform 3.0-inch thick Class "B" asphalt concrete wearing course were tested during this period. This pavement structure was built on a clay-silt subgrade soil.Instrumentation consisted of moisture tensiometers, strain gages, pressure cells, LVDT gages and thermocouples for measuring moisture, strain, stress, dynamic deflections and temperatures. Benkleman beam readings were taken.The testing period revealed that the fall failure modes were different from the spring failures. The fall failure patter started from transverse cracks in the thin sections which developed into alligator cracking patterns. These cracks appeared after a period of cold weather and heavy rains followed by a warming period. It seems that thermal and mechanical loads were responsible for the fall failures on the thin sections. The spring failures were very rapid and sudden and were due to environmental factors which led to saturated subgrade, thus resulting in poor bearing capacity. Punching shear was the failure mode. The thickest sections survived without cracks but developed severe rutting. Examination revealed that these ruts extended into the subgrade and that fatigue cracking was developing on the bottom of the bases.Comparison of the results with those obtained from Ring# 2, which was similar in base materials and thickness, show that they were similar in many respects. This indicates that the test track is capable of replicating results and is a reliable research instrument.Equivalencies were developed for the different materials. On this basis the special aggregate asphalt treated base was superior to the emulsion treated and untreated crushed rock bases in that order. These results were comparable to those obtained from test Ring #2.Maximum values for static and dynamic deflections, strains and stresses for different times and temperatures were developed. The lateral position of the dual tires with respect to the gage severely affected the strain, stresses and deflection values. Temperature also caused variations in the measurements. Spring instrument readings for static and dynamic deflections, strain and stress show increased values by as much as 2 to 4 times of those obtained in the fall. Spring subgrade conditions probably are responsible for these differences.Ring #3 series operational time was twice that of Ring #2 and sustained four times the wheel load applications. Construction and testing environmental conditions were superior to those for Ring #2 and hence contributed to the longer test period. This points out that environmental factors are very important in pavement life.

Authors:
Krukar,M., Cook,J. C.

Keywords:
aggregate, Alligator Cracking, applications, asphalt, asphalt concrete, base, base materials, bearing capacity, Benkleman beam, concrete, condition, construction, cracking, dual tires, environmental, equivalencies, experimental, fatigue, fatigue cracking, loads, materials, pavement, pavement life, pressure, pressure cell, rain, research, research at the WSU, soil, strains, stresses, subgrade, temperature, test track, tire, tires, volume, Washington, Washington state, wheel load

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