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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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    <item>
      <title>A History of Modern Accelerated Performance Testing of Pavement Structures</title>
      <link>https://trid.trb.org/View/1216941</link>
      <description><![CDATA[The type of research conducted at the National Center for Asphalt Technology’s (NCAT) Pavement Test Track is known as full-scale Accelerated Performance Testing (APT). APT is the controlled application of a prototype wheel loading, at or above the appropriate legal load limit, to a layered pavement system to determine pavement response and document performance as damage accumulates in a compressed time period. A great variety of APT experiments have been executed over the last hundred years. This document is the result of a literature review on the history and evolution ofAPT that was foundational to the success of the first research cycle at the NCAT Pavement Test Track.]]></description>
      <pubDate>Wed, 29 Oct 2014 11:25:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1216941</guid>
    </item>
    <item>
      <title>Evaluation of a Heavy Polymer Modified Asphalt Binder Using Accelerated Pavement Testing</title>
      <link>https://trid.trb.org/View/1245200</link>
      <description><![CDATA[As part of its Accelerated Pavement Testing (APT) program, the Florida Department of Transportation (FDOT) initiated, in 2001, an experiment to evaluate the effects of polymer modifiers on the rutting performance of Superpave mixes using a Heavy Vehicle Simulator (HVS). That study led to the use of PG 76-22 asphalt binder on the final structural course for traffic level D roadways (10 to >30 million ESALs) and the top two structural courses for traffic level E roadways (≥ 30 million ESALs). As a follow up, a study was conducted to evaluate the performance of stiffer polymer-modified binders meeting PG 82-22 requirements for focused use on intersections and other low speed facilities with concentrated heavy loads. This paper describes the research approach and findings. It is anticipated that the localized use of a PG 82-22 asphalt binder will significantly improve pavement performance at locations with historically excessive rut depths.]]></description>
      <pubDate>Thu, 07 Mar 2013 08:55:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1245200</guid>
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    <item>
      <title>Accelerated Pavement Testing of Low-Volume Paved Roads with Geocell Reinforcement</title>
      <link>https://trid.trb.org/View/1245196</link>
      <description><![CDATA[Four lanes of pavement test sections were constructed at the Infrastructure System Laboratory (CISL) of Kansas State University. Three of the four lanes had 75-mm geocell-reinforced bases and 25-mm cover of three different in-fill materials; crushed limestone, AB-3; quarry by-products; and Recycled Asphalt Pavement (RAP).The fourth test lanewas the control section consisting of 300-mm crushed stone (AB-3) base.The sections were paved with a 50-mm Superpave Hot-Mix Asphalt (HMA) layer. All sections were instrumented to measure the strains at the bottom of the HMA layer and stresses on top of the subgrade. The sections were loaded with 50,000 and 70,000 repetitions of an 80-kN single axle load of the Accelerated Pavement Testing (APT) machine. The failure rut depth was 12.5 mm. All sections except the control section had this rut depth by 10,000 repetitions. The calculated and measured responses show that on three test sections, stresses on top of the subgrade exceeded the unconfined compressive strength of the soil. The test sections were redesigned and reconstructed. The redesigned sections consisted of 100-mm geocell- reinforced bases, 50-mm cover, and an HMA layer of 100 mm. The same infill materials were used in the test sections. The control lane had a depth of 200 mm. These sections were also instrumented. All sections carried 1,200,000 repetitions of the 80-kN single axle loads with rut depths not exceeding 10 mm. Based on these results, a mechanistic-empirical design methodology for low-volume paved roads with geocell-reinforced bases is being developed.]]></description>
      <pubDate>Thu, 07 Mar 2013 08:55:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1245196</guid>
    </item>
    <item>
      <title>Accelerated Pavement Testing of Two Flexible Road Pavements to Assess Long-term Structural Performance</title>
      <link>https://trid.trb.org/View/1245198</link>
      <description><![CDATA[This paper presents the results of an accelerated pavement testing project conducted by Germany’s Federal Highway Research Institute (BASt). The main objective of the project was to evaluate the long-term structural performance of flexible road pavements under simulated heavy vehicle traffic. For this purpose two test sections of different strengths were subjected to dynamic impulse generator loading to simulate heavy vehicle loading. During loading, the condition of the pavement was monitored by periodic deflection measurements with a Falling Weight Deflectometer (FWD) and measurements of the transverse profile. Embedded sensors provided information on the dynamic mechanical response of the pavement under loading. The results showed a significant increase in the elastic strain at the bottom of the asphalt base course and a decrease in the bearing capacity. Furthermore structural bottom-up cracking in the asphalt base course was detected.A first approach to estimate the vertical propagation of cracks in asphalt pavement layers on the basis of the measured FWD surface deflections is presented.]]></description>
      <pubDate>Thu, 07 Mar 2013 08:55:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1245198</guid>
    </item>
    <item>
      <title>Accelerated Performance of a Failed Pavement on a Soft Clay Subgrade after Rehabilitation with High Polymer Mix at the NCAT Pavement Test Track</title>
      <link>https://trid.trb.org/View/1218599</link>
      <description><![CDATA[The Pavement Test Track is a full-scale, accelerated performance test facility for flexible pavements managed by the National Center for Asphalt Technology (NCAT) at Auburn University. Forty-six  unique 60-m test sections are installed around a 2.7-km oval and subjected to accelerated damage via a fleet of tractors pulling heavy triple trailers. Methods and materials that produce better performance for research sponsors are identified so that future pavements can be constructed based on objective life cycle comparisons. In this study, a 250-mm thick, full depth asphalt pavement that failed near the end of the previous research cycle was first rehabilitated using conventional methods. When the section failed a second time after less than half the traffic that produced the original failure, it was decided to rehabilitate the section again using the same high polymer mix that had performed well in another test section. Traffic applied to the high polymer rehabilitation has now surpassed the level needed to completely fail the original conventional rehabilitation, with no indication that another failure is pending. An overview of the original construction and subsequent rehabilitation of the failed pavement on a soft clay subgrade are included in this paper, with a focus on comparing the performance of the conventional rehabilitation with the high polymer content asphalt inlay.]]></description>
      <pubDate>Fri, 22 Feb 2013 15:39:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1218599</guid>
    </item>
    <item>
      <title>Evaluation of a Flexible Pavement Structure in an Accelerated Pavement Test</title>
      <link>https://trid.trb.org/View/1225099</link>
      <description><![CDATA[A flexible test road structure was built and tested in an Accelerated Pavement Test (APT) using a Heavy Vehicle Simulator (HVS) to investigate the performance behavior for validation in a  echanistic performance design. The structure was instrumented to measure the responses at different locations due to different wheel loadings and various tire pressures, with single and dual tires. The permanent deformation manifested on the surface as rutting was measured. The responses gained from various tire loads and pressures were analyzed using three approaches; all layers linear-elastic, the base nonlinear and base and subbase nonlinear. The measurements taken after 100,000 load repetitions were compared with the measurements taken in the beginning of the test. Some softening effect was noticed in the asphalt layers and was taken into account in the analysis. The observed accumulation of permanent deformation of the unbound layers was modeled using a three parameter model. Generally good agreement was established between the measured and calculated values.]]></description>
      <pubDate>Wed, 06 Feb 2013 12:48:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225099</guid>
    </item>
    <item>
      <title>Exploratory Evaluation of Cracking Performance of a 4.75 mm NMAS Overlay Using Full-Scale Accelerated Loading</title>
      <link>https://trid.trb.org/View/1225101</link>
      <description><![CDATA[State transportation agencies have begun to develop and implement specifications for 4.75mm Nominal Maximum Aggregate Size (NMAS) Superpave mixes with some specifications based on recommendations from a study conducted by the National Center for Asphalt Technology. These mixes restore surface texture and ride quality but also have advantages such as optimal use of available aggregates, accommodation of Reclaimed Asphalt Pavement (RAP), and application as an impermeable, thin preservation treatment. A trial 4.75mm NMAS from Virginia DOT was placed as a thin treatment on existing accelerated pavement test sections. The objectives of this study were to conduct full-scale load testing to gain confidence in a new mix design and to explore the ability of this thin treatment to curtail top down cracking. Several sub-sections, which were reserved and left unloaded from a preceding study, received a 25mmthick mill-and-fill with the 4.75mmNMAS mix. The construction produced a test section where half of the loaded wheel path was paved with the 4.75mm NMAS mix allowing a direct comparison of cracking performance with and without the thin treatment. Full scale accelerated aging was utilized to compare the fatigue cracking performance for four combinations; with and without 4.75mm NMAS treatment each with and without aging. Crack maps illustrated that the unaged 4.75mm mixture’s cracking performance exceeded the life of the sections without the treatment. Estimates of the increase in life provided by this thin treatment exceed 8 years. Forensic coring has shown top-down cracking to be the predominant distress. When aged, however, the 4.75mm treatment provided no additional life, but performed as well as an aged section without the treatment.]]></description>
      <pubDate>Tue, 29 Jan 2013 09:17:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225101</guid>
    </item>
    <item>
      <title>Rutting Resistance of Asphalt Pavements with Fine Sand Subgrade under Full-Scale Trafficking at High and Ambient Air Temperature</title>
      <link>https://trid.trb.org/View/1225102</link>
      <description><![CDATA[The rutting performance of an asphalt pavement structure with a fine sand subgrade and a high groundwater table was evaluated with full-scale trafficking tests with the Mobile Load Simulator 66 (MLS66) on Chong-ming Island, Shanghai.The purpose was to establish the reliability of the design with fine sand.There were two test sections with the same asphalt pavement structure but different subgrade depths. Track I was designed with a shallow 1.5m fine sand subgrade and Track II was designed with a medium 3.0m fine sand subgrade. The two tracks were constructed using traditional procedures on the natural clay subgrade covered with a layer of graded macadam. The asphalt pavements consisted of three asphalt layers (total 200 mm) and two cement-treated aggregate layers (total 540 mm, with 5% cement). The top 600mm to 800mm of the subgrade was treated with 3 to 4% cement. Track I was subjected to 1 million load applications at elevated temperature for 15 days and 1.1 million load applications were applied onTrack II at ambient air temperature for 17 days. Profile and temperature data were collected. Pavement profiles and diagnostic excavation indicated that pavement deformation originated from compression and shear flow of the asphalt materials. No fatigue cracking was observed. The influence of the fine sand subgrade and its depth on pavement rutting was negligible. Cores and pit surveys showed that the top asphalt layer of 120mm thickness was significantly affected by trafficked loading and temperature. The rate of rutting and total deformation volume of asphalt at high temperature was 1.5 times that of the test at ambient air ttemperature during early trafficking, about three times more thereafter. The rate of deformation on Track I was almost twice as fast as that ofTrack II. It is concluded that thick asphalt pavement with cement- treated-aggregate base will have good rutting resistance and can be expected to be a perpetual structure.]]></description>
      <pubDate>Tue, 29 Jan 2013 09:17:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225102</guid>
    </item>
    <item>
      <title>How Low Is Too Low? Assessing the Risk of Low Air Voids Using Accelerated Pavement Testing</title>
      <link>https://trid.trb.org/View/1225100</link>
      <description><![CDATA[Various forms of asphalt pavement distress can be attributed, in many cases, to low air voids in mixtures during production and placement.When lowair voids are encountered during production, the specifying agency must decide whether to require the material that has already been placed to be removed and replaced or whether it can be left in place. This study was conducted, in part, in the INDOT/Purdue Accelerated Pavement Testing (APT) Facility to develop a decision-support tool for dealing with such events that is based on projected rutting performance of the pavement system. The responses to repetitive APT wheel passes of test pavements with low air voids in either the surface or intermediate course were measured using a laser based system. The permanent deformation of the top pavement layers is used, in conjunction with simplified mechanistic analysis and engineering judgment, to formulate the desired decision-support tool.]]></description>
      <pubDate>Thu, 10 Jan 2013 08:55:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225100</guid>
    </item>
    <item>
      <title>Initial Test Results from the MLS10 Mobile Load Simulator in Switzerland</title>
      <link>https://trid.trb.org/View/1225103</link>
      <description><![CDATA[The Mobile Load Simulator (MLS10) is a new type of Accelerated Pavement Testing (APT) equipment recently purchased by Empa, Swiss Federal Laboratories for Materials Science and Technology. This paper summarizes the results of the first calibration tests of the MLS10 in Switzerland. The objective was to evaluate the performance of the machine for testing pavements constructed with local materials under local guidelines. The focus of the study was the structure of the A4 motorway near Zürich. Three pavements were constructed and trafficked with a total of 1.6 million 65 kN load passes over a period of approximately seven months. To access the structural response throughout the loading history, the pavements were instrumented with different sensors. Transverse profiles of the surface were periodically taken. FallingWeight Deflectometer (FWD) and static deflection bowl measurements were taken before, during, and after trafficking to evaluate the structural condition. Finally, pavement samples were obtained from the section and tested in the laboratory. The pavement response was analyzed and validated with a model using the Finite Element Method (FEM). At the end of the tests almost no sign of distress was observed, showing the durability of the pavement.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225103</guid>
    </item>
    <item>
      <title>Validating Permanent Deformation Tests Using Accelerated Pavement Testing</title>
      <link>https://trid.trb.org/View/1225116</link>
      <description><![CDATA[Using two case studies, this paper demonstrates the role that controlled accelerated pavement tests can play in the development of performance based laboratory testing procedures. Firstly, the results of an evaluation of the rut-resistant properties of asphalt mixes under accelerated loading using the Accelerated Loading Facility (ALF) conducted between November 1993 and May 1995 are summarized. The performance ranking of the asphalt mixtures is compared to the ranking determined using a dynamic creep laboratory test. The relative rankings of the mixes were different. The laboratory creep test results suggested that the minimum creep slope could rank the relative performance under ALF loading of mixes having the same composition but different binder type but not the relative performance of mixes having different gradings and compositions. The results of the ALF testing correlated better with the results of laboratory wheel-tracking testing. Secondly, a similar deformation trial was conducted on four different spayed seal surfaced, unbound granular pavements between July 2007 and June 2008. The work was undertaken as a means of validating a Repeated Load Triaxial (RLT) test procedure. The RLT test results brought into question the usefulness of the axial permanent strains measured in the test method as these strains did not identify one of the four test materials as being unsuitable for base course due to its low resistance to lateral shoving. By contrast a wheel tracking test, similar to that adopted after the 1990s asphalt work, correlated reasonably well with the ALF results.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225116</guid>
    </item>
    <item>
      <title>Performance of Thin Jointed Concrete Pavements Subjected to Accelerated Traffic Loading at the MnROAD Facility</title>
      <link>https://trid.trb.org/View/1225104</link>
      <description><![CDATA[With the growing trend in shrinking budgets, as well as increased concern for sustainable engineering, there is strong interest in determining how thin jointed concrete pavements can be constructed and still provide predictable long term performance. In 2008, five thin concrete test sections were constructed at the MnROAD pavement test facility toward addressing that question. Design slab thicknesses ranged from 130 to 165mm (5 to 6.5 in.). The sections were constructed on the MnROAD mainline roadway, thus exposing them to accelerated loading in the form of live, high volume interstate traffic. Other than some variations in panel length and dowel type for the thinnest sections, all other design variables were kept constant. This paper summarizes the performance of the test sections after more than two years of traffic and environmental exposure. Several pavement performance parameters were analyzed, including visual distress, joint faulting and load transfer efficiency, panel deflections, and ride quality. Observed performance was also compared to performance predicted by the current Minnesota Department ofTransportation pavement design procedure.Transverse and longitudinal cracking occurred on the thinner sections. Causes for each type of cracking are discussed. While the sections with slabs less than 150mm (6 in.) thick in this study withstood over 1.5 million CESALS before cracking, it is clear the thicker sections have much greater capacity. The data and observations gathered from these cells will benefit the continuing development of mechanistic–empirical design procedures for thin concrete pavements.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225104</guid>
    </item>
    <item>
      <title>Use of Accelerated Pavement Testing to Validate Ride Quality Index Data</title>
      <link>https://trid.trb.org/View/1225114</link>
      <description><![CDATA[Ride Quality Index (RQI) is the measure used by many state agencies to characterize pavement roughness for construction quality control or in their pavement management systems.The Minnesota Department of Transportation (MnDOT) uses RQI as a basis for determining what the driving public considers acceptable ride quality. To validate this concept, RQI measurements were analyzed for the 22 original asphalt test sections at MnROAD. These pavement test sections were built on the Mainline and Low Volume Road to study their performance under accelerated loading conditions. RQI data was collected twice per year on each section with a Pathways video inspection vehicle, similar to the data collected every year on 12,000 miles of the state highway network in Minnesota. Preventive maintenance treatments were applied at various times to various test sections to repair minor distresses and restore ride quality. This paper discusses the time required for each test section to reach a terminal serviceability level and compares it to the original three, five, or ten-year design life. The paper also considers the ride quality when microsurfacing was applied and the extension in life realized by the maintenance treatment. Finally, the paper examines the distress history within each cell to determine which surface distresses are most responsible for the deterioration in ride quality. The research shows how accelerated pavement testing can be used to validate ride quality concepts used in state pavement management programs. Although no statewide network data is presented in this paper, the MnDOT pavement management program does track the condition of highways over time and is able to quantify the benefits of extended life and reduced costs by applying preventive maintenance treatments.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225114</guid>
    </item>
    <item>
      <title>Towards Improved Characterization of Cemented Pavement Materials</title>
      <link>https://trid.trb.org/View/1225115</link>
      <description><![CDATA[Increasing use of high productivity road freight vehicles combined with more sophisticated approaches to pavement analysis has led to the need for improved knowledge of the performance of pavement materials. This paper describes the development of laboratory tests intended for routine assessment of strength, modulus and fatigue properties of cemented pavement materials. The laboratory tests involved a four-point bending flexural beam test. Methods for preparation of beam specimens in the laboratory and from field-placed cemented material are described. In order to provide materials performance data needed to verify the improved laboratory tests, the Australian Accelerated Loading Facility (ALF) was used to assess the fatigue performance of two cemented materials. A comparison of laboratory characterization results and full-scale ALF trial results was favorable providing confidence in the use of the laboratory techniques. Two cases involving implementation of the laboratory strength and modulus tests with practical outcomes are presented.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225115</guid>
    </item>
    <item>
      <title>The Implementation of Findings from Accelerated Pavement Testing in Pavement Design and Construction Practice</title>
      <link>https://trid.trb.org/View/1225117</link>
      <description><![CDATA[A series of laboratory and full scale Accelerated Pavement Tests (APT) were performed to quantify the effectiveness of geogrid stabilized flexible pavements. The measured responses at critical locations helped to improve understanding of the behavior and benefits associated with incorporation of a geosynthetic within unbound aggregate to form a Mechanically Stabilized Layer (MSL). The information obtained from APT combined with numerical modeling research helped to identify the key features that affect long-term performance of flexible pavements. Further, interpretation of the results generated from this combined approach was used to model the benefits of geogrids in pavement design. This paper presents a general approach to implement APT results in pavement design. This paper will also discuss other types of testing and research that can be used to reliably predict performance prior to establishing a full-scale APT program.]]></description>
      <pubDate>Wed, 09 Jan 2013 09:05:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1225117</guid>
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