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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>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <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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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A review of the composition, regeneration mechanism, and performance of cold recycled asphalt mixture</title>
      <link>https://trid.trb.org/View/2714522</link>
      <description><![CDATA[This review aims to enhance the mechanical and road performance of cold recycled asphalt mixture, and advocate the application of cold recycling technology, which features lower energy consumption and reduced carbon emissions. The properties of composition materials were initially studied for cold recycled asphalt mixture, meanwhile which regeneration mechanism was subsequently revealed. Additionally, a summary of the impact of complex factors on the mechanical and road performance of cold regenerated mixtures was provided, along with a proposed method for optimizing their performance. This review summarizes the main challenges of current cold recycling technologies and discusses future research directions. From numerous studies, it is found that the composition of cold recycled asphalt mixture significantly impacts its performance. The gradation variability and dosage of reclaimed asphalt pavement (RAP) material are the main factors affecting the performance of cold recycled material. The bonding property of binder has a significant effect on the mechanical properties of the mixture. The cold regeneration mechanism of waste asphalt mixture includes the rejuvenation of aged asphalt, the bonding mechanism of binder and the enhancement impact of additives. There are many factors affecting the performance of cold reclaimed asphalt mixture. Currently, improvements in mechanical and road performance can primarily be achieved through three main avenues: controlling the quality of RAP material, modifying the binders, and incorporating high-performance additives. However, the cold recycled asphalt mixture still faces several challenges, including a low utilization rate of RAP and limited application structure layers. In addition, insufficient early strength delays the opening of traffic. In the future, it is still necessary to propose more reasonable and efficient approaches to optimize the performance of cold reclaimed asphalt mixture, diverging from traditional methods. Moreover, the intelligent monitoring, evaluation, and prediction of performance for cold recycled asphalt pavement is also highly essential.]]></description>
      <pubDate>Mon, 27 Jul 2026 09:46:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2714522</guid>
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    <item>
      <title>Assessment of induced-healing maintenance for cold-recycled asphalt concretes using microwave heating and re-compaction</title>
      <link>https://trid.trb.org/View/2680512</link>
      <description><![CDATA[Proving the healing capabilities of cold asphalt pavements has gained significant attention in recent years, particularly through innovative methods such as induction and microwave heating. While these techniques effectively promote asphalt healing, heating alone is often insufficient to fully restore the material’s initial strength. The integration of re-compaction energy has been proposed to improve the effectiveness of microwave-based treatments in asphalt mixtures. This study examines the induced self-healing potential of cold reclaimed asphalt mixtures incorporating recycled asphalt pavement materials with varying black steel mill slag contents (0%, 10%, and 20% w/w). Results showed that the high healing rate had been achieved, demonstrating complete recovery of the initial ITS and highlighting the effectiveness of microwave heating and re-compaction in restoring the mechanical integrity of the mixture. The chemical and mineralogical characterization of the black steel mill slag proved iron oxide phase with high dielectric properties, which significantly enhanced microwave absorption and heating efficiency. The asphalt concrete sample containing 20% slag reached temperatures notably higher than the reference mix. These findings highlight the potential of microwave-induced healing, combined with re-compaction, as a sustainable and cost-effective approach to prolong pavement lifespan, reduce maintenance costs, and promote environmentally friendly road rehabilitation.]]></description>
      <pubDate>Wed, 17 Jun 2026 12:23:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2680512</guid>
    </item>
    <item>
      <title>Fast Track: Cold In-Place Recycle (CIR) and Full-Depth Reclamation (FDR) in Arizona</title>
      <link>https://trid.trb.org/View/2714397</link>
      <description><![CDATA[The primary goal of this study was to develop guidance materials for the Arizona Department of Transportation's (ADOT’s) consideration for the adoption and implementation of cold in-place (CIR) and full-depth reclamation (FDR) technologies. The first objective in accomplishing this goal was to summarize the current state of the practice on the key engineering factors that could contribute to the successful implementation of CIR, cold central plant recycling (CCPR), and FDR in Arizona. A second objective was to develop guidelines for project selection and help to identify some candidates for potential CIR and FDR projects in several ADOT districts. Preliminary FDR specifications and training materials were also developed to assist in training district engineers on CIR, CCPR, and FDR.]]></description>
      <pubDate>Mon, 15 Jun 2026 15:26:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2714397</guid>
    </item>
    <item>
      <title>Reclamation and Recycling Techniques to achieve Perpetual Pavements Characteristics</title>
      <link>https://trid.trb.org/View/2703795</link>
      <description><![CDATA[This study evaluates Cold In-place Recycling (CIR) for developing sustainable and cost-effective perpetual pavements. As part of the 2022 National Road Research Alliance (NRRA) construction, four test sections were constructed at the MnROAD mainline section to utilize CIR and additionally assess the effects of incorporating rejuvenator in cold recycled asphalt materials. Two sections included bituminous layer over aggregate base, while the other two included bituminous overlay over stabilized full depth reclamation (SFDR) base layer. For two sections, rejuvenator was incorporated to evaluate its impact on the performance of the cold recycled (CR) layer. Laboratory tests conducted after one year of service showed that even though rejuvenator improved binder fatigue resistance, its benefits were less evident at the mixture level, where cracking resistance declined. Perpetual pavement analysis indicated bottom-up cracking potential in all test sections but suggested that reasonable adjustments to overlay or CIR thickness could achieve perpetual behavior. The contrasting outcomes between binder, mixture, and Falling Weight Deflectometer (FWD) testing highlight the need for further research to fully understand the effect of rejuvenator on the CR layer/material behavior. Additional testing, focusing on fatigue, rutting, and low-temperature performance, is recommended to refine rejuvenator use in CIR applications and optimize cold recycling techniques for perpetual pavement construction.]]></description>
      <pubDate>Fri, 15 May 2026 17:15:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2703795</guid>
    </item>
    <item>
      <title>Study on water stability of hot in-place recycled asphalt mixture under temperature-pressure coupling</title>
      <link>https://trid.trb.org/View/2672275</link>
      <description><![CDATA[Water damage is a key factor limiting the service life of asphalt pavements, particularly hot in-place recycled (HIR) mixtures with high reclaimed asphalt pavement (RAP) content. Existing water stability evaluation methods fail to accurately simulate the temperature-dynamic water pressure coupled environment experienced in real pavements. To address this, this study employed a self-developed temperature-pressure coupled tester to systematically assess the water stability of HIR mixtures (90 % RAP, 10 % new aggregates). Comparing with traditional tests, the influences of key parameters (temperature, pressure, time, void content) were comprehensively examined alongside a significance analysis of influencing factors. Results show residual Marshall stability (MS₀) and tensile strength ratio (TSR) from traditional tests both exceed 95 %, failing to reveal substantial degradation under severe service conditions. In contrast, under coupled conditions (60 ℃, 0.8 MPa), these indices plummet to 58.48 % and 54.00 %, respectively, demonstrating a synergistic deterioration effect. The significance analysis ranks the influencing factors as follows: void content > dynamic water pressure > exposure time > temperature. A critical void content of 7–8 % was identified; beyond this threshold, water damage resistance declines sharply. Additionally, increased pressure and prolonged exposure significantly increase performance test result discreteness. This study provides a novel approach for objective evaluation of recycled asphalt mixtures’ water stability under actual service conditions.]]></description>
      <pubDate>Thu, 14 May 2026 14:00:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672275</guid>
    </item>
    <item>
      <title>Hot Recycling of Asphalt Pavements</title>
      <link>https://trid.trb.org/View/2683232</link>
      <description><![CDATA[The objective of this report is to evaluate the feasibility and benefit of utilizing asphalt pavement hot recycling in Oklahoma. The work began in April, 1980 and lasted through June, 1980. The 8 1/2 mile (13.6 km) project was located on I-40 in Caddo County. The project involved cold milling the top one inch (25 mm) of roadway. A non-woven polypropylene fabric, Petromat, was placed on the cold milled surface. This material was overlaid with 1 1/2 inches (38 mm) of the hot recycled mixture containing recycled asphalt concrete, virgin aggregate, and asphalt cement.]]></description>
      <pubDate>Sun, 12 Apr 2026 17:44:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2683232</guid>
    </item>
    <item>
      <title>Pilot Studies to Compare Single- and Multi-Unit Recycling Trains on Partial-Depth (Cold In-Place) Recycling Projects</title>
      <link>https://trid.trb.org/View/2686276</link>
      <description><![CDATA[The construction of two partial-depth (cold in-place) recycling projects was monitored and the quality control results were analyzed to compare gradations produced with single- and multi-unit recycling trains, to assess the effect of recycling train forward speed on gradation, and to compare differences between emulsified and foamed asphalt recycling agents in partial-depth recycling applications. The research highlighted the challenges with variability and small sample sizes associated with in-place recycling but provided representative and consistent results between projects. The results showed that there was no discernable difference in the density and strengths of partial-depth recycling layers produced with the single- and multi-unit recycling trains. The main benefit of the multi-unit train was better control of maximum aggregate size by the on-board screens and crushing unit, however, the crushing unit did not appear to change or improve the finer portion of the gradation (i.e., material passing the 5-mm sieve), which has a known larger influence on compaction density, air-void content reduction, strength, moisture resistance, and stiffness. The recycling train type and forward speed did influence the coarse portion of the gradation (i.e., >5 mm), but did not appear to influence compaction density. Test results indicated that the sections treated with emulsified asphalt had higher densities than those treated with foamed asphalt. However, there was considerable variability in materials and pavement structure along the length of the project, which probably had an influence on all results. The findings permit agencies to specify that recycling train and recycling agent choice can be the contractor’s decision.]]></description>
      <pubDate>Thu, 02 Apr 2026 15:23:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2686276</guid>
    </item>
    <item>
      <title>Cold Reclamation and Recycling Techniques to Achieve Perpetual Pavements</title>
      <link>https://trid.trb.org/View/2681395</link>
      <description><![CDATA[This study evaluates Cold In-place Recycling (CIR) for developing sustainable and cost-effective perpetual pavements. As part of the 2022 NRRA construction, four test sections were constructed at the MnROAD mainline section to utilize CIR and additionally assess the effects of incorporating rejuvenator in cold recycled asphalt materials. Two sections included bituminous layer over aggregate base, while the other two included bituminous overlay over stabilized full depth reclamation (SFDR) base layer. For two sections, rejuvenator was incorporated to evaluate its impact on the performance of the cold recycled (CR) layer. Laboratory tests conducted after one year of service showed that even though rejuvenator improved binder fatigue resistance, its benefits were less evident at the mixture level, where cracking resistance declined. Perpetual pavement analysis indicated bottom-up cracking potential in all test sections but suggested that reasonable adjustments to overlay or CIR thickness could achieve perpetual behavior. The contrasting outcomes between binder, mixture, and Falling Weight Deflectometer (FWD) testing highlight the need for further research to fully understand the effect of rejuvenator on the CR layer/material behavior. Additional testing, focusing on fatigue, rutting, and low-temperature performance, is recommended to refine rejuvenator use in CIR applications and optimize cold recycling techniques for perpetual pavement construction.]]></description>
      <pubDate>Fri, 20 Mar 2026 09:27:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2681395</guid>
    </item>
    <item>
      <title>Performance evaluation of polymer latex-modified asphalt emulsion and cold recycling mixture</title>
      <link>https://trid.trb.org/View/2645718</link>
      <description><![CDATA[Emulsified asphalt cold recycled mixture is an effective type of energy-saving and environmentally friendly road-building material. However, the base emulsified asphalt exhibits limited performance. Thus, polymer latexes, including Styrene-Butadiene-Styrene block copolymer (SBS), Styrene-Butadiene Rubber (SBR), and their hybrid systems, have emerged as effective modifiers to enhance the performance of emulsified asphalt. This study provides a thorough comparison of SBS latex-modified, SBR latex-modified, and SBS/SBR hybrid latex-modified emulsified asphalts, evaluating their rheological properties, adhesion characteristics, and pavement performance of asphalt mixtures, including fatigue resistance. Three latex-modified emulsified asphalts were prepared using the post-emulsification modification process. Dynamic Shear Rheometer (DSR) analysis showed SBS-modified emulsions had a 300 % higher complex shear modulus at 60 °C than the base emulsion. Bending Beam Rheometer (BBR) tests indicated SBR-modified emulsions had a 20 % lower complex modulus at − 24 °C. Boiling water adhesion tests revealed hybrid-modified emulsions had a 55 % lower gray scale value than single latex modifications. The radar chart evaluation system not only resolved the conflict between different test results for the same performance of the mixture but also enabled a quantitative analysis of comprehensive performance. Through this analysis, the SBR latex-modified asphalt mixture was identified as having the best overall performance. The findings were applied to lower course of the cold recycling test road, with core sampling tests verifying their stability and applicability in real service conditions. This work delivers a selection strategy for polymer latex-modified emulsified asphalts, offering tailored solutions for diverse pavement service environments.]]></description>
      <pubDate>Fri, 20 Mar 2026 08:41:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2645718</guid>
    </item>
    <item>
      <title>Recommendations for Standardizing Mix Design and Quality Control Testing Procedures for Asphalt-Treated Cold Recycled Materials</title>
      <link>https://trid.trb.org/View/2681410</link>
      <description><![CDATA[This paper summarizes a multiphase research project to standardize cold recycling specifications in California. The specifications for partial depth recycling (PDR), or cold in-place recycling, and cold central plant recycling (CCPR), using emulsified asphalt (EA) or foamed asphalt (FA), were developed independently, resulting in different mix design and quality control (QC) procedures for the two recycling agents. Most specifications require the use of Marshall stability for EA materials and indirect tensile strength (ITS) for FA materials. The specifications allow the use of gyratory compaction with 30 gyrations or Marshall compaction with 75 blows per face. This paper showed that, based on a review of 92 PDR and CCPR projects, the specification for EA produces mixes with lower binder and active filler contents. The two compaction methods were compared using field projects and laboratory testing, with the results showing that Marshall compaction overestimates density and, therefore, strength and stability, resulting in mixes with lower equivalent binder and active filler contents compared with gyratory, and facilitating passing minimum strength/stability criteria for QC. The comparison of the testing methods, using two different recycled asphalt pavement sources, and comparing the results with dynamic modulus results, indicated that Marshall stability does not produce a meaningful measure of the material properties. This paper recommends standardizing specifications for the EA and FA by removing Marshall compaction and Marshall stability, and adopting gyratory compaction and the ITS for mix design and QC testing. Attempting correlations between the different compaction and test methods is not considered appropriate.]]></description>
      <pubDate>Fri, 20 Mar 2026 08:38:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2681410</guid>
    </item>
    <item>
      <title>Cement Treated Base by Cold in Place Recycling Technology for Rural Roads</title>
      <link>https://trid.trb.org/View/2652203</link>
      <description><![CDATA[A large proportion of India’s villages have been connected with Water Bound Macadam (WBM) or bituminous roads. Rural roads usually have low volume of traffic, consisting mostly of light transport vehicles with less frequency of heavy traffic. Maintenance of these roads is neglected because of paucity of funds and the road asset created is in deteriorated condition. The non-availability of suitable soil and aggregates have made projects unviable and cost prohibitive. This aggregate scarcity will increase further as part of environmental conservation and restriction on mining. The stabilization of soil/aggregate is being used worldwide towards optimal usage of scares resources. The concept of cement treated base is included in IRC:37-2018 guidelines. The concepts of soil/aggregate stabilization and cold in place recycling technique provides a comprehensive solution for rehabilitation of existing road and green field road construction. Cold In Place Recycling process allow usage of locally available marginal materials. The stabilization process can use a wide range of stabilization agents such as soil-aggregate mix, lime, cement, fly ash, foamed bitumen, emulsion, polymers and other proprietary chemical stabilisers. Three rural roads are identified in Pune district. Pavements are designed considering cement treated base. The pavement cross section is analysed using IITPave and Street Pave software. These roads are constructed using cold in place recycling technique. The existing WBM/deteriorated bituminous surface is stabilised with cement. Bituminous concrete and Thin White Topping is provided as wearing course. The performance of pavement is evaluated after construction. The paper describes construction aspect, analysis and design, difficulties encountered and remedial measures suggested on three different case studies under consideration. The stabilised pavements offer superior strength and longevity, even in extreme climatic conditions and provide better performance. It is recommended to use cement treated base with cold in place technology for construction of rural roads.]]></description>
      <pubDate>Wed, 11 Mar 2026 14:44:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2652203</guid>
    </item>
    <item>
      <title>Cold In-Place Recycle (CIR) and Full-Depth Reclamation (FDR) in Arizona</title>
      <link>https://trid.trb.org/View/2672507</link>
      <description><![CDATA[Pavement recycling refers to the process of reclaiming materials from one or more layers of an existing pavement structure, processing them through mechanical or chemical stabilization, and then reusing them. The primary goal of this study was to develop guidance materials for the Arizona Department of Transportation's (ADOT’s) consideration for the adoption and implementation of cold in-place recycling (CIR) and full-depth reclamation (FDR) technologies. The first objective in accomplishing this goal was to summarize the current state of the practice on the key engineering factors that could contribute to the successful implementation of CIR, cold central-plant recycling (CCPR), and FDR in Arizona. A second objective was to develop guidelines for project selection and help to identify some candidates for potential CIR and FDR projects in several ADOT districts. Preliminary FDR specifications and training materials were also developed to assist in training district engineers on CIR, CCPR, and FDR.]]></description>
      <pubDate>Tue, 10 Mar 2026 09:54:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672507</guid>
    </item>
    <item>
      <title>Recycling PCC Pavements in Oklahoma</title>
      <link>https://trid.trb.org/View/2657963</link>
      <description><![CDATA[This report describes the first Portland cement concrete (PCC) pavement recycling project in Oklahoma. A 7.755-mile section of I-40 in eastern Oklahoma County was recycled. It had passed its original 20-year design life and was experiencing "D-cracking" to a point that maintenance costs were becoming excessive. The nine-inch-thick plain slab was recycled into a ten-inch plain slab. Included in the final report is a description of the construction activities, energy conservation estimates, construction cost comparisons and measures of pavement performance. A professionally narrated video tape documenting the complete construction effort is available.]]></description>
      <pubDate>Mon, 09 Mar 2026 11:53:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2657963</guid>
    </item>
    <item>
      <title>Improving and Developing Pavement Design Inputs and Performance Functions for Cold Recycled Pavement Layers in Minnesota</title>
      <link>https://trid.trb.org/View/2672492</link>
      <description><![CDATA[Existing specifications in Minnesota and many other states fail to adequately characterize the properties of cold recycled pavement materials necessary for pavement design procedures. Current assumptions for these materials are not entirely accurate as these materials often possess complex, non-linear, stress and rate dependent behavior. This can lead to under/overdesigned pavement structures that are not economically and environmentally viable. Adequately characterizing the recycled material layer will ensure that the appropriate thickness of wear course is determined through pavement design with no negative impact on structural capacity or serviceability. This research, through a series of laboratory and field investigations, develops a user-friendly, Excel-based material property prediction tool to estimate necessary material properties to be used in quality assurance evaluation and/or performance modelling efforts within mechanistic-empirical design of cold recycled pavement structures. In addition, a rutting performance function and early life rutting failure threshold is developed to assist in minimizing the risk of premature rutting failure of the recycled layer. From these, longer pavement lives can be achieved, leading to a decrease in the frequency of repair and maintenance as well as the costs associated with them.]]></description>
      <pubDate>Wed, 04 Mar 2026 09:15:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672492</guid>
    </item>
    <item>
      <title>Evaluating the role of base binder type and aging severity on restoration capacity of rejuvenating agents for sustainable asphalt recycling</title>
      <link>https://trid.trb.org/View/2643644</link>
      <description><![CDATA[The use of rejuvenating agents (RAs) is crucial in restoring the properties of aged asphalt binder during hot mix recycling. Studies on the effectiveness of RAs for unmodified binder (UMB) and polymer-modified binder (PMB) under different aging severities are scarce, yet necessary for enabling repeated hot mix recycling. This study examined the rejuvenation capacity of four RAs (fresh mustard oil, waste cooking oil, waste engine oil and tall oil) for UMB and PMB. Laboratory aging was performed to achieve aging index (AI) of 1.27?±?0.01 and 1.5?±?0.01, representing moderate and severe aging degrees. Various RA dosages were added to the aged binder, and the physical, rheological and performance properties were measured to estimate the optimum rejuvenator dosages. A storage stability test and Fourier transform infrared (FTIR) spectroscopy were performed to evaluate RA compatibility and chemical changes induced by the RAs, respectively. The results showed that RAs effective for UMB were not equally effective for PMB because of polymer degradation in aged-PMB. RA performance was highly dependent on binder type and aging severity. High RA dosages, especially in severely aged binders, can lead to poor storage stability. RAs restoring stiffness (G*) and phase angle (d) are recommended for efficient hot mix recycling.]]></description>
      <pubDate>Thu, 15 Jan 2026 14:31:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643644</guid>
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