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    <title>Research in Progress (RIP)</title>
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    <atom:link href="https://rip.trb.org/Record/RSS?s=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMTYiIC8+PC9wYXJhbXM+PGZpbHRlcnM+PGZpbHRlciBmaWVsZD0iaW5kZXh0ZXJtcyIgdmFsdWU9IiZxdW90O0NyYWNraW5nJnF1b3Q7IiBvcmlnaW5hbF92YWx1ZT0iJnF1b3Q7Q3JhY2tpbmcmcXVvdDsiIC8+PC9maWx0ZXJzPjxyYW5nZXMgLz48c29ydHM+PHNvcnQgZmllbGQ9InB1Ymxpc2hlZCIgb3JkZXI9ImRlc2MiIC8+PC9zb3J0cz48cGVyc2lzdHM+PHBlcnNpc3QgbmFtZT0icmFuZ2V0eXBlIiB2YWx1ZT0icHVibGlzaGVkZGF0ZSIgLz48L3BlcnNpc3RzPjwvc2VhcmNoPg==" 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>Research in Progress (RIP)</title>
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      <link>https://rip.trb.org/</link>
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    <item>
      <title>Reclamation and Recycling Techniques to achieve Perpetual Pavements Characteristics</title>
      <link>https://rip.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://rip.trb.org/View/2703795</guid>
    </item>
    <item>
      <title>SPR-5031: Developing INDOT Road Crack Image Datasets for Advanced Analytics Research</title>
      <link>https://rip.trb.org/View/2691526</link>
      <description><![CDATA[The Indiana Department of Transportation (INDOT) requires a comprehensive, annotated crack image dataset from falling weight deflectometer (FWD) testing to enable advanced analytics for pavement management. This project delivers systematically labeled crack images to correlate with structural deflection data, and standardized annotation protocol. Dataset enables automated crack detection, enhanced structural assessment capabilities, and data-driven pavement management decisions while leveraging existing image archives cost-effectively through annotators.]]></description>
      <pubDate>Wed, 06 May 2026 14:55:27 GMT</pubDate>
      <guid>https://rip.trb.org/View/2691526</guid>
    </item>
    <item>
      <title>Effects of Target Air Voids on Hot Mix Asphalt (HMA) Performance Tests</title>
      <link>https://rip.trb.org/View/2698280</link>
      <description><![CDATA[To test the performance of hot-mix asphalt (HMA), Illinois Department of Transportation (IDOT) uses volumetrics testing, which tests the air void content and voids in mineral aggregate in compacted samples, followed by balanced mix design — which uses performance tests to evaluate pavement distresses. This project aims to identify if compacted HMA specimens that are currently discarded after volumetric testing can be used in performance tests. Researchers will test volumetric specimens at 4% and 7% air void content in cracking and rutting performance tests and identify if an alternate rutting test can be used in production. Successfully using compacted volumetric specimens for performance testing may reduce the time needed to identify if an HMA mixture meets IDOT performance test criteria at the start of production.]]></description>
      <pubDate>Fri, 01 May 2026 09:19:25 GMT</pubDate>
      <guid>https://rip.trb.org/View/2698280</guid>
    </item>
    <item>
      <title>Investigation of Reflective Cracking in Wisconsin</title>
      <link>https://rip.trb.org/View/2671979</link>
      <description><![CDATA[This research aims to determine mixture performance and mix design requirements that increase the resistance of asphalt overlays to reflective cracking in Wisconsin. Recommendations must not sacrifice other critical performance or constructability attributes, such as rutting resistance and smoothness. Research efforts should focus on mill and overlay and overlay over existing Portland Cement Concrete design scenarios. Summarize existing mix design and performance requirements for asphalt overlays used by local and State Agencies in regions with similar climatic and aggregate resources as Wisconsin. Identify and recommend process-driven methods and technologies that show promise in reducing reflective cracking in Wisconsin. Using existing Wisconsin Department of Transportation (WisDOT) mixtures as a benchmark, modify or supplement the existing WisDOT balanced mix design (BMD) special provision focusing on BMD “Approach C” for mixtures designated for asphalt overlays. Researchers will summarize relevant local and State practices concerning asphalt overlays and reflective cracking resistance, focusing on regions with similar climate, traffic, and aggregate resources as Wisconsin. Identify potential process-driven methods and technologies to improve reflective cracking resistance for recommendation as future WisDOT research. Using the existing WisDOT BMD special provision as guidance, researchers will preferentially modify or supplement the provision using BMD “Approach C” to reduce the reflective cracking of asphalt overlays. Develop recommendations and requirements to validate the BMD framework developed in prior tasks. Recommendations should consider a minimum number of projects, mix design designations (such as traffic level), project scope and size, and requirements for mixture sampling and data acquisition, among other variables.]]></description>
      <pubDate>Wed, 18 Feb 2026 11:13:16 GMT</pubDate>
      <guid>https://rip.trb.org/View/2671979</guid>
    </item>
    <item>
      <title>Design Requirements for High Traffic Asphalt Mixes to Ensure Pavement Performance</title>
      <link>https://rip.trb.org/View/2671978</link>
      <description><![CDATA[High Traffic Asphalt Mixes in Wisconsin Department of Transportation (WisDOT) are routinely using Stone Matrix Asphalt compacted to 100 design gyrations. Concerns have arisen that the mixtures contain low asphalt contents and are difficult to compact in the field. A more equitable balance between mixture stiffness and cracking resistance is desirable to optimize and/or improve the constructability and performance of High Traffic Asphalt Mixtures. The project objective is to modify WisDOT Hot Mix Asphalt design requirements for High Traffic mixtures to improve constructability and performance for high-volume freight corridors over a 20-year design life. The project will involve summarizing existing mix design requirements in regions with similar climates ("Wet- Freeze") and aggregate resources, benchmark existing WisDOT mixture designs using volumetric and performance testing and use a combination of laboratory-reproduced mix designs and construction/in-service performance data to propose modifications to existing mixture designs and procedures.]]></description>
      <pubDate>Wed, 18 Feb 2026 11:11:29 GMT</pubDate>
      <guid>https://rip.trb.org/View/2671978</guid>
    </item>
    <item>
      <title>Next-Generation Weather-Resistant Pavement Foundations -- High Strength and Durable Stabilized Base Courses </title>
      <link>https://rip.trb.org/View/2665668</link>
      <description><![CDATA[Durability of the pavement foundation is critical to ensuring a sustainable and resilient roadway infrastructure and minimizing life-cycle costs. This research project explores innovative techniques and materials to improve the durability of base layers, a crucial component of a typical asphalt pavement foundation. The objectives of this project are to explore cement-stabilized FDR mixes with high stiffness for base courses with enhanced resistance against shrinkage cracking. The scope of work consists of preparing and testing FDR mixes with cement (both Type I/II and Type IL) as the main stabilizer, and various concentrations of crack mitigation asphalt emulsions with high maltene content (CM-Emulsion), analyzing the results, and preparing conclusions and recommendations. The cement stabilized materials will be tested for shrinkage crack potential, compressive and indirect tensile strength, and will be evaluated for mineralogical information using XRD for each combination of test variables. The conclusions and recommendations from this study are expected to be beneficial for constructing long-lasting pavements. ]]></description>
      <pubDate>Wed, 04 Feb 2026 15:33:49 GMT</pubDate>
      <guid>https://rip.trb.org/View/2665668</guid>
    </item>
    <item>
      <title>Use of Advanced Data Capture Tools on Measurements of Crack Lengths and Potholes for Estimates and Final Quantities</title>
      <link>https://rip.trb.org/View/2652613</link>
      <description><![CDATA[According to the Pavement Management Information System, the Kansas Department of Transportation (KSDOT) maintains 11,357 miles of pavement (counting miles in both directions of divided highways).  About 90% of this mileage is asphalt pavement. KSDOT’s contract maintenance work related to crack sealing, pot-hole patching, etc., is common for these pavements. 

The current measurement techniques use a measuring wheel, distance measuring instrument (DMI), etc. These techniques are highly susceptible to human errors and utilize considerable time and manpower. They also obstruct the traffic flow while conducting roadway measurements and putting the personnel at risk. The KSDOT idea submitted cites data collection via high-accuracy drone surveys but drone operations are restricted on KSDOT right of ways to prevent traveler distraction.   

Recent developments in camera technology and high-speed, high-resolution image capture at an affordable cost offer the opportunity for automation of measurements of crack lengths and potholes/patches for estimates and final quantities.  Example camera models include Vantrue S1 Pro 2.7K Front and Rear 5G WiFi Dash Cam, VIOFO Dash Cam Front and Rear 2K 1440P 60fps, Dash Cam Front and Rear - POFOTO 2.5K 1440P 60fps and 1080P 30fps Dash Camera, VIOFO A129 Plus Dash Cam 2K 1440P 60FPS GPS Wi-Fi Car Dash Camera with HDR and equivalent. These cameras all cost less than $250. 

The challenge lies in processing the images. However, with recent developments in artificial intelligence and machine learning, this problem can be resolved relatively quickly. One such algorithm for spatial pattern analysis is Convolutional Neural Networks (CNN), which have developed rapidly and have been applied in computer vision, natural language processing, and other fields. The convolutional neural network mimics the biological visual perception mechanism and can carry out supervised and unsupervised learning. However, traditional CNN has some drawbacks, like as the number of layers increases, the quality of the model decreases, ultimately leading to a decline in supervised learning accuracy. Thus, newer algorithms based on CNN have been developed that will be deployed in this study.]]></description>
      <pubDate>Tue, 13 Jan 2026 16:08:53 GMT</pubDate>
      <guid>https://rip.trb.org/View/2652613</guid>
    </item>
    <item>
      <title>Evaluation of Longitudinal Joint Densities of Asphalt Pavements in Kansas</title>
      <link>https://rip.trb.org/View/2652473</link>
      <description><![CDATA[The longitudinal joint between hot-mix asphalt (HMA) mats is often the weakest part of a bituminous concrete pavement. These joints often deteriorate fast under traffic because cracks in them allow water to ingress into the pavement, leading to further disintegration. Many studies, including one by the Federal Highway Administration (FHWA) and the Asphalt Institute in 2012, have fully recognized this. 

It is believed that the longitudinal cracks result primarily from the density gradient encountered across the joint during HMA construction.  This density gradient can be attributed to low density at the unconfined edge when the first lane is paved and relatively high density at the confined edge when the adjacent lane is paved. The water infiltrates through the low-density area with high air voids and results in premature failures. The other causes of longitudinal cracks include loss in temperature during rolling; height differential due to poor construction (difficulty in compacting the unconfined edges) or differential settlements; residual stress (occurring at the wheel path as the HMA mat density increases) that exceeds the tensile strength of the HMA; and temperature and environmental forces. 

Asphalt pavement joints can be cold or hot. The cold joints occur where the first lane pavement has cooled overnight or longer, before the next lane is placed or where the first lane is carried so far ahead that the face has cooled to well below 120o F. Hot joints are produced by two pavers operating in echelon spaced close enough together so that the lane placed first does not cool significantly before the other lane is placed. There are many conventional joint compaction techniques such as rolling from the hot side, rolling from the cold side, and echelon paving. Various longitudinal joint construction techniques are being practiced now with varying results.
 
Starting in October 2002 letting, the Kansas Department of Transportation (KSDOT) added longitudinal joint density (for HMA lift thickness greater than 1 in.) evaluation procedure to all bituminous pavements as a subsection 603.03(e)(2) in Special Provisions 90M-6917 following the specifications of the Texas Department of Transportation. The traveled way joint density was evaluated by taking two or three Nuclear Density Gauge readings in the transverse direction one paver-width wide. The traveled-way joint density, either one or two locations, is subtracted from the interior density and the difference in density compared to the allowable limits. The acceptable criterion for the joint density was interior density-joint density < 50 kg/m3.  Since then, the specification has been modified as (Interior Density - Joint Density) ≤3.0 lb/ft3 or Joint Density ≥ 91.0% of Gmm, where Gmm is the theoretical maximum HMA specific gravity.  

Many agencies including the U.S. Army Corps of Engineers, Connecticut DOT, Michigan DOT, and Pennsylvania DOT have established pay schedules for joint densities. Thus, research on potential pay schedules for joint densities in Kansas to improve the quality of HMA pavement construction is worth pursuing. 
]]></description>
      <pubDate>Tue, 13 Jan 2026 15:50:31 GMT</pubDate>
      <guid>https://rip.trb.org/View/2652473</guid>
    </item>
    <item>
      <title>Evaluation of High-Resolution Imaging Method to Characterize Cracking Resistance of Asphalt Mixtures </title>
      <link>https://rip.trb.org/View/2646967</link>
      <description><![CDATA[This research project aims to advance the cracking resistance characterization of asphalt concrete mixtures by integrating a high-resolution, dual-camera imaging system into Balanced Mix Design cracking performance tests, such as the IDEAL-Cracking Test and Overlay Test. The motivation for this study stems from the critical need to improve the durability of asphalt pavements subjected to increasing traffic-induced and environmental stresses. The primary objective is to validate a dual-camera imaging system capable of capturing and quantifying vertical crack growth on both sides of asphalt mixture specimens with high accuracy and repeatability. The research will involve system evaluation, image data analysis, and comparison with conventional test metrics to support asphalt mixture and pavement design. Project tasks include the evaluation of the imaging system, execution of controlled cracking tests, and detailed analysis of crack initiation and propagation patterns. The anticipated outcomes include enhanced insight into cracking behavior across different asphalt mixtures, improved methodologies for assessing material performance, and identification of mixtures with superior crack resistance. By leveraging high-resolution imaging techniques, this research will not only provide a deeper understanding of the mechanisms driving cracking but also facilitate the optimization of asphalt formulations to mitigate such failures. Additionally, the findings could serve as a valuable resource for engineers and policymakers aiming to implement more weather-resilient infrastructure solutions in response to the increasing demands of modern transportation systems. ]]></description>
      <pubDate>Tue, 06 Jan 2026 17:21:14 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646967</guid>
    </item>
    <item>
      <title>Lightweight, Durable, and Cost-Effective: Advancing Voided Concrete Technology with Engineered Cementitious Composites  </title>
      <link>https://rip.trb.org/View/2646966</link>
      <description><![CDATA[Voided concrete technology, which integrates hollow plastic spheres into concrete to create a lightweight, material-efficient structure, has gained attention in construction for its ability to reduce concrete use by 30–50% and for its lower dead loads. This innovation is particularly promising for transportation infrastructure such as bridge decks, railway platforms, and parking garages where weight reduction directly impacts foundation costs and construction efficiency. Current voided concrete systems demonstrate 70–90% of conventional slab and beam load-bearing capacity, with enhanced flexural performance due to optimized reinforcement distribution. However, limitations persist: (i) reduced stiffness and shear resistance compared to solid slabs/beams, (ii) sensitivity to sphere placement errors, requiring specialized labor, and (iii) durability concerns in high-stress environments like heavy-traffic bridge decks. These challenges hinder broader adoption in transportation, where structures demand high durability, fatigue resistance, and minimal maintenance.  

This project will evaluate replacing conventional concrete with Engineered Cementitious Composites (ECC) in the existing voided concrete technology to address current limitations while leveraging material synergies. Indeed, ECC, reinforced with polyethylene fibers, offers superior mechanical performance in tensile ductility and strain-hardening behavior, mitigating shear and crack propagation issues in voided slabs and beams. In addition, the compressive strength exceeds that of conventional concrete, which in turn compensates for capacity reductions from voids. In terms of durability in harsh environments, the crack-width control in ECC enhances corrosion resistance, which is critical for bridge decks exposed to de-icing salts. Finally, the proposed solution is cost-effective through material efficiency as ECC’s higher cost is offset by combining its performance with voided concrete material reduction.  

This study will include a series of mechanical tests on lab-scale voided biaxial beams made with ECC and regular concrete to assess the viability and quantify the expected improvements in structural behavior. The study will provide crucial information on the newly proposed voided ECC technology and will explore: (i) the possibility of constructing longer bridge spans with reduced deck weight, minimizing pier and foundation requirements, (ii) an accelerated construction via potential prefabricated ECC voided modules, and (iii) potential service life extension through enhanced fatigue and corrosion resistance. ]]></description>
      <pubDate>Tue, 06 Jan 2026 17:19:21 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646966</guid>
    </item>
    <item>
      <title>Evaluation of UHPC Shell Stay-in-Place Formwork and BCSA Cement Concrete Prestressed Girders</title>
      <link>https://rip.trb.org/View/2646949</link>
      <description><![CDATA[Precast prestressed bridge girders are used for a large percentage of bridges in the United States. These bridges are susceptible to deterioration at the supports due to leaking expansion joints and end region cracking caused by high stresses at the beam ends. This project will evaluate the feasibility and structural performance of a hybrid precast, prestressed concrete girder system that utilizes an ultra-high performance concrete (UHPC) shell stay-in-place formwork or end region insert and rapid setting belitic calcium sulfoaluminate (BCSA) cement concrete. UHPC is a relatively recent advancement in cementitious composite materials with mechanical and durability properties far exceeding those of conventional concrete. This research is intended to address the concern of end region durability by encapsulating the girder concrete with a nearly impermeable layer of UHPC that is also resistant to cracking. The rapid setting of BCSA cement concrete and use of stay-in-place forms can increase the speed of production of the prestressed girders and BCSA cement concrete has reduced prestress losses over time.  

The research will consist of evaluating small-scale behavior of composite UHPC shell and BCSA cement concrete compression and flexural elements, and construction and testing of large-scale prestressed beam elements. The objectives of the project are to evaluate the feasibility of using rapid setting BCSA cement concrete in conjunction with a UHPC shell for prestressed concrete elements, determine flexure and shear failure mechanisms and associated capacity for composite UHPC shell elements, and develop effective interface details for the UHPC shell to BCSA cement concrete. This work will be conducted through a series of five tasks. Task 1 will evaluate the surface preparation and deformation compatibility using small-scale testing. Task 2 will consist of the design of prestressed beam specimens using different shell surface preparations and locations along the beam. Task 3 will consist of prestressed beam specimen construction. Task 4 will include flexural and shear testing of the prestressed beam elements. Task 5 will consist of preparing reports and disseminating the project information. ]]></description>
      <pubDate>Tue, 06 Jan 2026 09:02:05 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646949</guid>
    </item>
    <item>
      <title>Assessing the Durability and Long-Term Performance of Rejuvenated Asphalt Mixes with RAP </title>
      <link>https://rip.trb.org/View/2646944</link>
      <description><![CDATA[This research idea addresses an important Oklahoma Department of Transportation (ODOT) need to use higher amounts of recycled materials in asphalt mixes, which is essential for the statewide implementation of Balanced Mix Design (BMD). Rejuvenators have been used successfully to restore the properties of asphalt mixes containing Reclaimed Asphalt Pavement (RAP). There is a wide variety of petroleum-based and bio-based rejuvenators available commercially that purport to improve the performance of asphalt mixes with RAP. A crucial aspect of the design of these mixes is to ensure durability and long-term performance. Some additives may only impart a short-term effect and aid in mix compaction without showing a sustained long-term effect on performance. In this study, rejuvenated asphalt mixes with RAP will be prepared, using local materials from Oklahoma, and assessed to evaluate their long-term performance, including raveling resistance and stripping susceptibility. A comprehensive testing plan will be developed and conducted for testing of both asphalt binder and asphalt mixture. The test plan includes mixture testing to assess the moisture susceptibility using Tensile Strength Ratio (TSR) and Hamburg Wheel Tracking (HWT) tests. The HWT test results will be analyzed using the corrected rut depth (CRD) and striping number (SN) parameters to evaluate rutting and moisture resistance. The mixes will also be tested using IDEAL-CT at both short-term aged and long-term aged conditions to ensure durability and balanced performance. The binder testing will include evaluating the rheological properties of the binders at extended Pressure Aged Vessel (PAV) aging durations. The binders will also be evaluated using Fourier Transform Infrared (FTIR) spectroscopy to assess aging susceptibility. The proposed study will provide valuable information on the effectiveness of rejuvenators on asphalt mixture performance during service life. The findings of this study will be used to propose specification requirements for rutting, cracking, and moisture-induced damage for rejuvenated asphalt mixes considering long-term performance and durability. ]]></description>
      <pubDate>Mon, 05 Jan 2026 23:09:53 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646944</guid>
    </item>
    <item>
      <title>Evaluation of Low-Cost Engineered Cementitious Composites with Incorporation of Cellulose Nanocrystals </title>
      <link>https://rip.trb.org/View/2646935</link>
      <description><![CDATA[Cellulose nanocrystals are a type of nanomaterial derived from cellulose, which have gained interest due to their effect on concrete materials. This research study aims to investigate the effect of Cellulose nanocrystals on the mechanical properties of cost-effective Engineered Cementitious Composites (ECC). To accomplish this goal, four levels of nanocellulose will be evaluated. In addition, two types of Engineered Cementitious Composites mixtures will be assessed; one with sugarcane bagasse ash (SCBA) and without SCBA. A comprehensive experimental program will be conducted to evaluate the compressive, tensile, and flexural performance of the Engineered Cementitious Composites mixtures. Results will provide insights into the effects of nanocellulose on the mechanical behavior of low-cost Engineered Cementitious Composites materials.  

The scope of this study is to investigate the effect of cellulose nanocrystals on the mechanical properties of cost-effective Engineered Cementitious Composites. The objectives of the proposed research are to synthesize cellulose nanocrystals from rice husk through acid hydrolysis treatment, prepare two sets of mixtures of Engineered Cementitious Composites: one with SCBA as sand replacement and one without SCBA, evaluate the compressive, tensile and flexural performance of Engineered Cementitious Composites mixtures, and evaluate the cracking behavior of Engineered Cementitious Composites materials after uniaxial tensile test. ]]></description>
      <pubDate>Mon, 05 Jan 2026 22:23:21 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646935</guid>
    </item>
    <item>
      <title>Tools to Improve the Durability of Asphalt Pavements</title>
      <link>https://rip.trb.org/View/2607896</link>
      <description><![CDATA[In recent years, a number of new construction technologies, new asphalt materials, and new methods to control pavement temperatures have emerged as potential tools to improve the durability of asphalt materials. For example, warm mix asphalt (WMA) mixtures require lower mixing and compaction temperatures, which lower the emissions generated at the mixing plant, and at the same time, reduce the short-term aging of asphalt materials, and therefore increase their resistance to thermal cracking. Also, it has been shown that the addition of various amounts of polymer modifiers can increase the cracking resistance. A number of new materials, some based on bio-binders, have shown a reduction in the heat absorption of the pavement surface, which can reduce long term aging and increase the durability of pavements, while at the same time reducing the heat island effects that have a negative effect on people living in urban areas. In addition, studies have shown, including current studies at University of Minnesota, that tree shade can have a significant effect on pavement temperature, and therefore the durability of pavement.]]></description>
      <pubDate>Wed, 08 Oct 2025 11:34:56 GMT</pubDate>
      <guid>https://rip.trb.org/View/2607896</guid>
    </item>
    <item>
      <title>2501 Evaluate the Performance and Consistency of BMD Mixes during Production using Rheological and Chemical Binder Testing</title>
      <link>https://rip.trb.org/View/2606534</link>
      <description><![CDATA[This project is part of an ongoing plan by Oklahoma Department of Transportation (ODOT) to implement Balanced Mix Design (BMD) and to promote asphalt recycling. The overall objective of this study is to build on the findings of previous studies conducted by ODOT, and to provide more insight into the performance and variability of BMD mixes, which will guide ODOT in its efforts to develop specifications for BMD. The specific objectives that will be addressed in this proposal are: Quantify the variability of BMD mixes during production using mixture and binder testing, including mixes from different asphalt plants, and constituting a wide variety of local materials and mix designs. Identify test methods that are appropriate to use to assess the variability of mixes, focusing on cracking, rutting, and binder rheological and chemical properties. The test methods will be evaluated based on their ability to capture the variability during production. The analysis will also include studying correlations between binder testing and mixture testing. Guidelines will be developed to evaluate the impact of variability on mix production and how to incorporate the variability into mix acceptance specifications. A statistical approach to incorporate the variability in mix acceptance specifications will be specified, including methods such as percent within limits (PWL), to ensure mix consistency during production.]]></description>
      <pubDate>Fri, 03 Oct 2025 11:08:00 GMT</pubDate>
      <guid>https://rip.trb.org/View/2606534</guid>
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