<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3ARb%2A" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. 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><image><title>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>Evaluation of Healing Potential of Asphalt Mixtures Modified with Nanoparticle-Enhanced Binders</title><link>http://pubsindex.trb.org/view/2712014</link><description><![CDATA[This study investigates the fatigue and healing performance of asphalt mixtures incorporating nanoparticle-modified binders, using nanoclay and nanosilica. Two binders (PG 58-28 and PG 76-22) were selected to assess their effect on healing behavior. Asphalt mixtures were prepared using granite aggregates and UFGS Gradation 3, then subjected to mechanical and simulation-based evaluations. Cyclic fatigue testing was conducted using the asphalt mixture performance tester at 25°C, with a strain amplitude of 800 microstrains and a loading frequency of 10 Hz. To simulate in-service conditions, 10- and 20-minute rest periods were introduced after 25% of the specimen’s estimated fatigue life, representing early stage fatigue damage accumulation. Healing was quantified by comparing the number of cycles to failure (Nf) before and after rest period. Dynamic modulus testing and FlexPAVE™ simulations were also performed to assess viscoelastic behavior and long-term pavement performance. Results showed that both nanoclay and nanosilica modified mixtures exhibited notable improvements in fatigue life relative to the control, with nanoclay modified mixtures achieving the highest fatigue life improvement, while nanosilica modified mixtures demonstrated consistent intermediate gains across both binder types. FlexPAVE™ simulations indicated a 37% reduction in total fatigue damage over 20 years for nanoclay-modified mixtures with rest periods. Rutting and cracking resistance also improved significantly, as observed from indirect tensile asphalt cracking test and asphalt pavement analyzer tests. The findings confirm that nanomodification, especially with nanoclay, enhances the intrinsic healing capacity, fatigue resistance, and durability of asphalt mixtures. Incorporating rest periods in design further optimizes long-term performance, offering a sustainable strategy for modern pavement systems.]]></description><pubDate>Tue, 09 Jun 2026 10:54:11 GMT</pubDate><guid>http://pubsindex.trb.org/view/2712014</guid></item><item><title>Medium-Term Oven Aging and Rapid Medium-Term Oven Aging for the Implementation of Balanced Mix Design</title><link>http://pubsindex.trb.org/view/2711995</link><description><![CDATA[The selection of an appropriate long-term laboratory aging protocol for implementing balanced mix design remains a concern within the asphalt industry. In this study, two different loose mix aging protocols were applied: medium-term oven aging (MTOA) and rapid medium-term oven aging (RMTOA). MTOA protocol involved loose mix aging for 20 h at 100°C, whereas a temperature of 135°C was considered for RMTOA for a quick turnaround time. To determine the equivalent aging duration for RMTOA to produce similar aging effects as MTOA, six different asphalt concrete mixes containing reclaimed asphalt pavement (RAP) and recycling agents (RA) were oven aged at different aging temperatures and durations. Aging indices of the binders extracted from these mixes were applied to the Arrhenius equation to obtain the activation energy for different mix types. Despite the mixes differing in binder sources (four refineries) and RAP contents (up to 40%), the activation energy ranged narrowly between 68.1 kJ/mol to 72.9 kJ/mol. The use of Arrhenius activation energy suggested that around 3 h at 135°C laboratory aging (RMTOA) simulated the similar aging parameters of MTOA protocol (20 h at 100°C). In the second stage of this study, indirect tensile IDEAL cracking tolerance tests were performed on both RMTOA- and MTOA-aged specimens. Seven different AC mixes containing RAP and RA were considered to characterize the age-related cracking performance after MTOA and RMTOA. The ANOVA analysis indicated that two aging procedures (MTOA and RMTOA) are expected to produce similar effects on the IDEAL-CT results.]]></description><pubDate>Tue, 09 Jun 2026 10:54:11 GMT</pubDate><guid>http://pubsindex.trb.org/view/2711995</guid></item><item><title>Durability and Microstructural Performance of Self-Compacting Concrete Made with Recycled Aggregates</title><link>http://pubsindex.trb.org/view/2711984</link><description><![CDATA[The present study investigates the durability and microstructural behavior of self-compacting concrete (SCC) made with recycled aggregates (RA) under aggressive environmental conditions, including sulfate, acid, and chloride attacks. Three RA replacement ratios (0%, 50%, and 100%) were examined. The study evaluates the influence of RA on the chemical resistance of SCC, supported by microstructural analysis using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results reveal that RA content influences the performance of SCC in aggressive environments. Under sulfate exposure, the mix with 100% RA showed higher expansion rates (96% in magnesium sulfate and 53% in sodium sulfate) compared with the control mix (64% and 24%, respectively). Similarly, in acid environments, the 100% RA mix exhibited greater mass loss (12.6% in sulfuric acid and 9.2% in hydrochloric acid) than the control mix (7% and 5.7%, respectively). Furthermore, chloride penetrability increased with RA content, as evidenced by a higher charge passed, from 3,378 coulombs for the control mix to 4,586 coulombs for the 100% RA mix at 28 days. Microstructural analysis identified the formation of expansive products such as ettringite and gypsum in sulfate-exposed samples, while acid exposure led to the formation of calcium chloride and non-expansive salts, contributing to material changes. The study highlights that attached mortar play a significant role in the behavior of SCC under aggressive conditions. These findings demonstrate that RA can be effective when used in SCC, though careful consideration of its properties is essential to ensure performance in challenging environments.]]></description><pubDate>Tue, 09 Jun 2026 10:54:10 GMT</pubDate><guid>http://pubsindex.trb.org/view/2711984</guid></item><item><title>Optimized Laboratory Fabrication of Small-Specimen Geometry for Streamlining Dynamic Modulus and Cyclic Fatigue Testing of Asphalt Mixtures</title><link>http://pubsindex.trb.org/view/2709230</link><description><![CDATA[The asphalt community is focused on the paradigm shift in mixture design from the volumetrics to an optimization procedure based on performance testing called balanced mixture design. Streamlining performance testing to obtain index properties quickly and using a smaller quantity of materials is critical for the successful implementation. This paper aims to streamline dynamic modulus (|E*|) and cyclic fatigue testing by optimizing the number of 38 mm diameter specimens extracted from a single 150 mm diameter Superpave gyratory-compacted (SGC) specimen. The current provisional standard methods require vertical coring of four small specimens from a single SGC specimen. In this study, two sets of testing specimens were fabricated by coring four and five small specimens from each SGC specimen. The success rate in meeting target air voids, the |E*| analysis, and the cyclic fatigue results including cyclic fatigue index parameter (Sₐₚₚ) values were compared between the two sets of specimens. No significant or consistent differences were observed in performance testing results. Furthermore, innovative image analysis and microscopy techniques were used to study air voids distribution and aggregate structure within each specimen and to further validate the proposed coring pattern. Based on these findings, coring five 38 mm diameter testing specimens from one SGC sample is suggested to run |E*| and cyclic fatigue tests. This proposed modification to AASHTO TP 132 and TP 133 may save technicians’ time and allows for the optimal use of materials. The latter may become a significant saving when integrating these methods with laboratory long-term aging protocols and forensic studies.]]></description><pubDate>Tue, 02 Jun 2026 11:01:49 GMT</pubDate><guid>http://pubsindex.trb.org/view/2709230</guid></item><item><title>Mechanistic Analysis and Design Framework for Geosynthetic Stabilized Unpaved Roads</title><link>http://pubsindex.trb.org/view/2709229</link><description><![CDATA[Geosynthetics provide mechanical stabilization benefits to paved or unpaved roads through lateral restraint of unbound aggregate particles and bearing capacity improvement over weak subgrades. The current state of the art incorporating geosynthetics into paved or unpaved road design involves conducting proper elastic layered system mechanistic analysis to determine the improvement of aggregate layer stiffness for increased traffic capacity or reduction in aggregate layer thickness. This paper presents a mechanistic analysis and design pipeline for determining the required aggregate thickness via the finite element (FE) modeling approach. An advanced FE analysis tool, C-FLEX, was employed to analyze axisymmetric multilayered unpaved road structures, accounting for the nonlinear stress-dependent behavior of unbound aggregates. The modulus enhancements were quantified for 10 different geosynthetics using the latest Bender Element sensor technology in both triaxial and large-scale tests conducted on typical dense-graded base aggregates. They were then incorporated into base course stiffness characterization via a sublayering approach for the unpaved road comprising aggregate base placed over soft subgrade. Both the measured enhanced moduli and the the extent of geosynthetic influence zones were adequately established in the sublayering approach. Further, sensitivity analysis was conducted for different aggregate modulus models and different sublayer structures, which verified the proposed design pipeline to provide satisfactory results. The method was also compared with the Giroud and Han method, which revealed the inherent difference in the two methods, given that the design here is based on the critical pavement responses and subgrade strength, while the Giroud and Han method also incorporated the field data with performance evaluation.]]></description><pubDate>Tue, 02 Jun 2026 11:01:49 GMT</pubDate><guid>http://pubsindex.trb.org/view/2709229</guid></item><item><title>Cold-in-Place Recycling with 100% Recycled Asphalt Pavement Rejuvenated by Soybean Oil: Laboratory and Field Evaluation</title><link>http://pubsindex.trb.org/view/2709232</link><description><![CDATA[This study investigated the feasibility and performance of using soybean oil as a bio-based recycling agent in recycled asphalt pavement (RAP) for road reconstruction in cold regions. A comprehensive demonstration project was conducted on a 5-mile section of Old State Road in Clare County, Michigan, where a 100% RAP mixture modified with soybean oil was produced and placed using a conventional asphalt paver equipped with a screed. Laboratory evaluations included balanced mix design, rutting and cracking testing, and binder performance analysis. Field application processes, including mixing and compaction, were also documented and evaluated. The asphalt mixture tests included the Hamburg wheel-tracking test (HWTT) and the indirect tensile asphalt cracking test (IDEAL-CT), while the asphalt binder tests included dynamic shear rheometer (DSR), asphalt binder cracking device (ABCD), rotational viscometer (RV), linear amplitude sweep (LAS), Fourier transform infrared spectroscopy (FTIR), and CO2 emission analysis. An optimal soybean oil dosage of 1.0 wt.% (based on the total weight of the mix) significantly improved low-temperature cracking resistance and fatigue life while maintaining rutting resistance. Results showed that soybean oil improved compaction performance and exhibited a cracking temperature approximately 3.3°C lower than that of untreated RAP based on the ABCD test. Fatigue performance was also enhanced. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the chemical compatibility and interaction between soybean oil and the RAP binder. On-site application was completed smoothly without workability issues, and the final pavement met all compaction and density requirements. In summary, using soybean oil as an RAP recycling agent provides a practical and environmentally friendly solution to improve the performance of recycled asphalt mixes, especially for low-volume roads in cold climates, while supporting the sustainability of Michigan’s pavement and the growth of the soybean market.]]></description><pubDate>Mon, 01 Jun 2026 16:52:46 GMT</pubDate><guid>http://pubsindex.trb.org/view/2709232</guid></item><item><title>Evaluation of Critical Pavement Responses from Accelerated Pavement Testing on Airfield Flexible Pavements Surfaced with Hot and Warm Mix Asphalt</title><link>http://pubsindex.trb.org/view/2709231</link><description><![CDATA[Highway agencies frequently use warm mix additives as compaction aids. Lower production temperature of the warm mixes simultaneously entails the benefit of widening the paving window. Airport authorities can ensure significant fiscal savings with reduced downtime through the adoption of similar technologies in airfield paving. However, limited scientific information exists concerning the performance of these materials in airside flexible pavements. Aircraft gross weights and tire pressures have also been routinely increasing over the last few decades with the advent of new-generation aircraft. The Federal Aviation Administration (FAA) procured a sixth-generation heavy vehicle simulator, airfields (HVS-A) to investigate the performances of resilient pavement materials under simulated aircraft loading. Accordingly, six full-scale test lanes were constructed during Test Cycle 1 (TC1) at FAA’s National Airport Pavement and Materials Research Center (NAPMRC) using four different asphalt concrete (AC) mixes with two different binder grades. Each test lane was divided into three test sections. Asphalt strain gauges and pressure cells were installed in the test sections to monitor the critical pavement responses over the duration of traffic tests. Corresponding test sections were trafficked under different combinations of high tire pressure and temperature. This paper examines the tensile strains at the bottom of AC and compressive stresses on top of the subgrade in reference to the observed rutting performances in four TC1 outdoor test lanes. The respective hot and warm mixes exhibited comparable rutting performances, and the sensor observations corroborated the related findings.]]></description><pubDate>Mon, 01 Jun 2026 16:52:46 GMT</pubDate><guid>http://pubsindex.trb.org/view/2709231</guid></item><item><title>Balancing Thickness and Quality: Economic Design Framework for Flexible Pavement Foundations in Minnesota</title><link>http://pubsindex.trb.org/view/2705415</link><description><![CDATA[In Minnesota, pavement designers have traditionally favored premium Class 5/6 base aggregates directly beneath asphalt or concrete surface layers, while relegating lower-quality materials to thicker subbase layers or excluding them entirely. With the limited supply of high-quality aggregates and the steady increase in transportation costs posing restrictions for pavement construction and maintenance, local agencies are increasingly exploring the use of lower-quality, locally available materials in pavement foundation layers. This study evaluated the effects of both material quality and layer thickness requirements of base and subbase on flexible pavement performance and the associated cost, with the objective to develop an optimal design framework for statewide use, particularly in areas where locally sourced high-quality aggregates are limited. To this end, resilient modulus and strength characteristics were studied to classify Minnesota aggregate sources into high-, medium-, and low-quality levels, which were then incorporated into MnPAVE mechanistic pavement analyses for multiple traffic loads, asphalt thicknesses, subgrade stiffnesses, and Minnesota climate zones. In parallel, cost–benefit analyses were conducted to identify the most economical quality–thickness combinations of unbound aggregate base and subbase using historical bid-price data available from Minnesota Department of Transportation (DOT). An iterative procedure developed for a design framework in this research effort determines the optimal base and subbase thicknesses each aggregate quality level is required to satisfy fatigue- and rutting-life criteria for conventional flexible pavements. The resulting guidance enables local agencies to use regional materials more efficiently when high-quality aggregate materials are in short supply, while delivering sustainable and cost-optimized pavements across the state.]]></description><pubDate>Tue, 26 May 2026 09:44:22 GMT</pubDate><guid>http://pubsindex.trb.org/view/2705415</guid></item><item><title>Assessment of Geopolymer Synthesis Parameters for Strength of Stabilized Fat Clay Using Statistical and Machine Learning Techniques</title><link>http://pubsindex.trb.org/view/2704073</link><description><![CDATA[Calcium-based chemical stabilizers are traditionally used for the stabilization of weak subgrade soils. However, these traditional stabilizers incur significant environmental costs which make them less desirable. As a result, alternative materials based on recycled waste and industrial byproducts are becoming popular. Geopolymers (GP) are a new addition to this list that are gaining traction because of their environmental benefits. GPs improve the soil by precipitation of a polymer gel as a result of mixing an alkaline activator (activator) with an aluminosilicate source (precursor). The effectiveness of GP and the improvement in engineering performance of GP-stabilized soils is contingent on sound GP synthesis parameters. This study investigates the effectiveness of GP-based treatments in improving weak soil and evaluates the significance of various parameters in contributing to the efficacy of GP treatment. As a result, a group of eight GP mixes was designed with a range of values for controlling parameters namely water/solid, activator/precursor, Si/Al and cation/Al ratios. A fat clay was treated by the application of these GP mixes at a dosage of 10% by dry weight. Improvements in mechanical strength were evaluated through unconfined compression strength testing. This was followed by statistical inference on laboratory strength data using analysis of variance (ANOVA) and post hoc tests. Ultimately, parameter importance was quantified by the random forest (RF) regression model. The results indicated that GP-based treatments enhanced the strength of untreated soil. Additionally, GP with higher aluminosilicate content and sufficient activator performed better. Overall, this study provides insight into the relative contribution of various GP synthesis parameters to the performance of GP-stabilized subgrade soils.]]></description><pubDate>Thu, 21 May 2026 09:09:19 GMT</pubDate><guid>http://pubsindex.trb.org/view/2704073</guid></item><item><title>Crack Performance Modeling of Mixtures and Pavements with Consideration of Aging, Moisture Conditioning, Climatic Zone, and Reclaimed Asphalt Pavement Mitigation Strategies</title><link>http://pubsindex.trb.org/view/2703809</link><description><![CDATA[Pavement performance prediction is essential for developing durable asphalt mixtures that meet long-term service requirements. With growing interest among transportation agencies in maximizing the use of recycled asphalt materials (RAM) to promote sustainability and cost-effectiveness, challenges persist in ensuring adequate durability of high-RAM mixtures. This study, conducted as part of the NCHRP Project 09-65, aimed to enhance RAM utilization while maintaining performance standards related to cracking resistance and durability. Six robust asphalt mixtures—representative of two distinct climatic zones and designed using various high-RAM mitigation strategies—were selected based on their performance in laboratory assessments. These mixtures were evaluated using two mechanistic pavement modeling approaches: a fracture mechanics-based cohesive zone model and a continuum damage mechanics-based FlexPAVE™. A representative pavement structure of the Federal Highway Administration’s Pavement Testing Facility and laboratory test results of mixtures formed the inputs for the models. Results from both modeling approaches confirmed that RAM mitigation strategies such as the use of recycling agents, polymer-modified asphalt, and reduced RAM binder availability can significantly affect early- and long-term resistance to cracking. Although performance prediction and rankings differed slightly between the two pavement modeling methods, the combined approach offers a mechanistically grounded framework for evaluating and optimizing high-RAM asphalt mixtures for durable pavement structure.]]></description><pubDate>Tue, 19 May 2026 09:02:16 GMT</pubDate><guid>http://pubsindex.trb.org/view/2703809</guid></item><item><title>Revised Faulting Model to Account for Dowel Looseness and Corrosion in Long-Life Pavements</title><link>http://pubsindex.trb.org/view/2703802</link><description><![CDATA[The current AASHTOWare Pavement Mechanistic-Empirical Design faulting model framework has several limitations, which prohibit the consideration of alternative dowels commonly used in long-life pavements. Users cannot account for key design parameters, such as dowel stiffness, which is a critical need given the increased use of alternative dowel bars. Also, the effect of corrosion is not integrated into the model. Lastly, because of a lack of available faulting data from doweled pavements, the calibration alone is unable to account for the effect of loss of dowel performance resulting from corrosion. This study presents a revised faulting model framework which incorporates key design, loading, and environmental parameters. First, a comprehensive dowel damage model was developed based on an accelerated dowel loading test. The damage model incorporates critical parameters such as dowel stiffness which, before this work, could not be directly considered. Second, a novel corrosion model informed by a laboratory analysis is incorporated to account for the reduction of dowel diameter caused by corrosion. Lastly, the concept of “equivalent dowel diameter” was introduced into the faulting model. The faulting model was calibrated using faulting data from a national database of in-service pavements. A series of model adequacy checks was conducted to demonstrate that the model does not exhibit bias and to illustrate the effect of key parameters on predicted faulting. The improved faulting model framework is the first comprehensive model able to account for damage accumulation resulting from both vehicle loads and corrosion for the range of dowel bars currently on the market.]]></description><pubDate>Mon, 18 May 2026 14:04:39 GMT</pubDate><guid>http://pubsindex.trb.org/view/2703802</guid></item><item><title>Long-Term Mechanical and Environmental Performance Monitoring of Steel Slags in Granular Roadways</title><link>http://pubsindex.trb.org/view/2701376</link><description><![CDATA[Recent years have seen the use of steel slag in roadway applications. This is primarily driven by the growing emphasis on utilizing recycled materials to promote sustainable development. However, this widespread utilization also raises concerns related to long-term mechanical performance and environmental effects. This study evaluates the long-term mechanical and environmental performance of steel slag used in granular roadway layers over 7 years. The steel slag used in this study was electric arc furnace slag, sourced from two suppliers with different gradations (Types A and B). Both types were placed at two layer thicknesses (5.08 and 10.16 cm), and their in situ and laboratory properties were thoroughly analyzed. The field and laboratory tests included the dynamic cone penetrometer, light weight deflectometer, resilient modulus M[subscript R], permanent deformation, X-ray diffraction, pH, electrical conductivity, and elemental concentrations. The results indicate that both slag types exhibited increasing stiffness and strength because of ongoing hydration and carbonation processes, with steel slag Type A (coarser gradation) showing a higher M[subscript R] compared with Type B. The results of the 5.08 cm steel slag surface layers were comparable with the 10.16 cm layers, emphasizing the potential for design optimization to mitigate environmental risks. The effects of field carbonation, to effectively stabilize toxic elements, were reflected in pH and metal concentration measurements in the surrounding soils. Although laboratory tests indicated higher pH and elemental release for steel slag aggregates, conditions in the laboratory were extreme, causing disruption of protective carbonate layers, compared with those observed in the field. Both steel slag types demonstrated mechanical characteristics comparable to natural aggregates, offering a sustainable alternative.]]></description><pubDate>Fri, 15 May 2026 09:18:58 GMT</pubDate><guid>http://pubsindex.trb.org/view/2701376</guid></item><item><title>Effect of Waste Perlite Powder as a Replacement for Natural Filler on the Mix Design and Performance Properties of Slurry Seal Surface Treatment</title><link>http://pubsindex.trb.org/view/2701303</link><description><![CDATA[The reuse of industrial waste materials in infrastructure projects presents a promising approach to reduce natural resource consumption and minimize environmental impacts. This study examines the performance of waste perlite powder (WPP) as a sustainable alternative to conventional natural fillers in slurry seal mixtures. Five mix designs were prepared by partially replacing the natural filler with WPP at 0%–10% total aggregate weight, corresponding to 0%–100% replacement of the original filler (constituting 10% of the aggregate). The mixtures were evaluated using a comprehensive set of standardized tests, including mixing time, wet cohesion, sand adhesion, wet track abrasion test (WTAT), and loaded wheel tracking (LWT), as well as determining the optimum residual bitumen content. The WPP at 75% (WPP75) achieved 28.4 kg·cm of wet cohesion at 60 min, a 16% reduction in sand adhesion, and a greater than 50% improvement in abrasion resistance (355 g/m2 versus 728 g/m2 in the control). Wheel tracking tests indicated reductions of 25.7% and 42.3% in vertical and lateral displacements, respectively, highlighting improved deformation resistance. A higher WPP content increased water demand; all mixtures retained acceptable mixing times (&gt; 180 s). Overlay analysis of WTAT and LWT results identified an optimal residual bitumen range of 8.03%–8.66%, with WPP75 showing the highest bitumen demand. A two-way analysis of variance showed that WPP content, bitumen dosage, and their interaction significantly affected performance, accounting for most of the response variability. Incorporating up to 7.5% WPP is technically viable and environmentally advantageous, enhancing the durability, cohesion, and sustainability of slurry seal pavements.]]></description><pubDate>Fri, 15 May 2026 09:18:58 GMT</pubDate><guid>http://pubsindex.trb.org/view/2701303</guid></item><item><title>Predicting Retroreflectivity Degradation of Pavement Marking Using a Bayesian Ordered Logit Model</title><link>http://pubsindex.trb.org/view/2701298</link><description><![CDATA[Adequate pavement marking retroreflectivity RL is crucial in enhancing road safety, and cost-effective marking restriping planning requires RL deterioration models and service life estimation. This paper presents the Bayesian ordered logit model that incorporates Markov Chain Monte Carlo simulation to predict the degradation trend in RL using data collected from representative highways in Wyoming. The results indicate that the marking age and characteristics, geometric locations, pavement surface, traffic volume, and snowplow operations are the significant factors affecting pavement marking degradation. The results indicate that the lane line and center line are more prone to degradation compared with the edge line. In addition, the degradation rate is higher for white markings than for yellow markings and in the curve section compared with the straight section. Cumulative traffic, truck traffic passage, and snowplow operation also significantly affect RL degradation. The outcomes derived from the distinct models reveal substantial differences among the three functional classification models and justify investigating separate models. By integrating the random intercept into the modeling process, the analysis found a notable presence (from 22% to 31%) of unobserved heterogeneity within the same route, a crucial aspect that ensures the attainment of accurate and unbiased results. This paper also proposed a prediction equation to determine pavement marking service lives and reveals that the service life of different materials varies based on road classification, marking material, and line position. The proposed model is readily implementable and can assist pavement marking management by effectively scheduling restriping and maintenance periods for different materials.]]></description><pubDate>Fri, 15 May 2026 09:18:58 GMT</pubDate><guid>http://pubsindex.trb.org/view/2701298</guid></item><item><title>Microscopic Analysis of Particle Regularity Effects on Cyclic Shear Behavior at Gravel–Geogrid Interfaces</title><link>http://pubsindex.trb.org/view/2701386</link><description><![CDATA[The apparent shape of particles is a key determinant of the mechanical properties of a gravel–geogrid interface. A quantitative analysis of particle shape was conducted to study the effect of particle regularity on the cyclic shear characteristics of a gravel–geogrid interface. The discrete-element method was utilized to establish particles of varying regularities in particle flow software and to simulate direct shear tests. Changes in porosity, coordination number, shear band proportion, particle rotation angle, and fabric anisotropy were analyzed for varying particle regularities and cycle numbers. The results demonstrate that the vertical displacement and shear stress of the gravel–geogrid interface increase with decreasing particle regularity. The interface exhibits reduced porosity and elevated coordination number for lower-regularity particles. The shear band proportion decreases with increasing particle regularity, with low-regularity particles having 1.4–1.7 times more shear band proportion than high-regularity particles. The rotation angle of a particle with a regularity of 0.707 is only 0.4–0.6 times that of a particle with a regularity of 0.975, showing an opposite trend to the shear band proportion. Simultaneously, particles within the shear band also show a significantly higher rotation angle than those outside. Additionally, the mean rotation angle decreases with increasing cycle number. The principal stress direction of the contact force at the gravel–geogrid interface shifts with the increase in shear displacement. The deflection of the direction of the principal stress axis between high-regularity particles is slightly less than that of low-regularity particles.]]></description><pubDate>Thu, 14 May 2026 17:01:53 GMT</pubDate><guid>http://pubsindex.trb.org/view/2701386</guid></item></channel></rss>