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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Aggregate fracture in unbound road materials</title>
      <link>https://trid.trb.org/View/2752052</link>
      <description><![CDATA[This thesis introduces a new numerical framework, combined with an experimental study, to predict aggregate fracture in UGMs and quantify its influence on UGM macro-mechanical behavior. The framework is based on the discrete element method (DEM) and enables evaluation of aggregate fracture for varying gradations, loading conditions, and aggregate types. To ensure general applicability, granular mechanics-based contact laws and statistical fracture models are developed and incorporated into DEM. The model parameters are identified and the framework validated through laterally confined monotonic uniaxial compression tests on UGMs. The tested materials included different aggregate types and gradations and were subjected to different maximum compressive loads. For UGMs composed of crushed granite, the DEM model captures the effects of gradation and load magnitude on both macro-mechanical response and aggregate fracture. To extend the framework to a wider range of aggregates, particularly marginal-quality aggregates, a new particle fracture model is developed that accounts for aggregate shape variability and statistical volume effects on fracture force distributions. The model is evaluated using single-particle crushing tests on four aggregate types and compared with two widely used fracture models, showing improved agreement with measured aggregate strength. When implemented in the DEM framework, the new model improves fracture predictions for UGMs containing marginal-quality aggregates. The feasibility of using DEM to assess how aggregate fracture affects elastic stiffness and permanent deformation resistance of UGM is evaluated. Emphasis is put on UGMs containing marginal aggregates and on the potential for optimizing pavement structural design to enable their use without excessive performance loss. Blended UGMs containing crushed granite and crushed brick are investigated using confined compression tests and X-ray CT, and the observations are incorporated into the DEM model to predict both macro-mechanical behavior and aggregate fracture]]></description>
      <pubDate>Fri, 07 Aug 2026 08:36:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2752052</guid>
    </item>
    <item>
      <title>Effects of structural details on brittle crack arrestability in thick cross-joint components under different propagation scenarios</title>
      <link>https://trid.trb.org/View/2701518</link>
      <description><![CDATA[Brittle fracture poses significant risks in large container ships; therefore, enhancing brittle crack arrestability is essential for structural integrity. While structural design offers a promising route, a critical gap remains: the lack of quantitative understanding regarding how realistic crack propagation scenarios influence brittle crack arrestability. This study addresses this gap by investigating thick cross-joint components—critical welded details that connect the deck plate and hatch coaming and play a decisive role in maintaining the safety of container ships—under three realistic scenarios: Scenario Zero (S0), without discontinuities, simulating full penetration welding; Scenario One (S1), with discontinuities, crack propagation from hatch coaming to deck; Scenario Two (S2), also with discontinuities but in the reverse direction. Specimens were designed for crack arrest tests to simulate these scenarios using PMMA capable of capturing high-speed crack propagation/arrest behaviour, similar to that observed in steel, in situ. Experimental results demonstrated that discontinuities significantly improved crack arrestability in S1 but had negligible effect in S2. To further analyse these effects, a high-fidelity s-version-finite-element-based framework was employed to simulate high-speed crack propagation/arrest behaviour. Numerical results revealed that, compared to S0, discontinuities reduced the dynamic stress intensity factor by up to 44% in S1—equivalent to using materials with an arrest toughness increased by nearly 80%—while showing negligible effect in S2. These findings provide the quantitative and mechanistic clarification of how structural details affect brittle crack arrestability and offer both scientific insight and practical design guidance for improving the safety of large welded marine structures.]]></description>
      <pubDate>Thu, 06 Aug 2026 09:22:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2701518</guid>
    </item>
    <item>
      <title>Material Development for Cold Spray Valve Seat</title>
      <link>https://trid.trb.org/View/2695914</link>
      <description><![CDATA[The material for the cold spray valve seat was developed to form a straight port which was effective for strong tumble flow. Hardness is necessary to ensure wear resistance, but if the material is hard, plastic deformation during particle impact becomes difficult, and the adhesion between particles and between the coating layer and the substrate decreases. In order to solve this trade-off, it was realized in the composite layer of Corson alloy which is an age-hardening copper alloy and Cobalt base hard particle. In this development, it was found that the fracture strength was improved by the addition of hard particles, and the phenomenon of Ni silicide which seemed to be effective for the fracture strength improvement was discovered.]]></description>
      <pubDate>Fri, 31 Jul 2026 09:23:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2695914</guid>
    </item>
    <item>
      <title>Preparation and toughening mechanism of high-toughness cold-mixed epoxy asphalt</title>
      <link>https://trid.trb.org/View/2694111</link>
      <description><![CDATA[This study presents a formulation and preparation process for high-toughness cold-mixed epoxy asphalt (HTCEA). The optimal formulation was determined as: 140 parts epoxy resin, 80 parts curing agent, 40 parts epoxy diluent, 10 parts toughening agent, and 20 parts compatibilizer, through analyzing the influence of these components on HTCEA performance. Following this, the preparation process for Component A (composed of epoxy resin, diluent, toughening agent, and compatibilizer) and Component B (composed of base asphalt, asphalt diluent, and curing agent) was optimized. The established parameters involved stirring Component A at 60 °C and 500 r/min for 30 min, followed by mixing Components A and B at 500 r/min for 3 min. The optimized formula and process resulted in an HTCEA with a tensile strength of 2.45 MPa, an elongation at break of 166.28%, and a pot life of 50 min. Compared with conventional CEA, the tensile strength increased by 93% (from 1.27 MPa to 2.45 MPa) and the elongation at break improved by 35% (from 123.60% to 166.28%). It exhibits excellent mechanical properties and processability. The mechanical behavior and toughening mechanism were further investigated at the microscopic scale using molecular dynamics simulation. The simulation results indicate that the optimized HTCEA possesses a bulk modulus of 2.71 GPa, a shear modulus of 0.83 GPa, and a Young's modulus of 2.97 GPa, confirming excellent micro-mechanical properties. The enhancement is primarily attributed to the incorporation of flexible chain segments from the polyurethane toughening agent, which modifies the epoxy cross-linked network. At the same time, it significantly enhances the intermolecular interactions and entanglements, promoting the formation of a more uniform and dense three-dimensional network. Consequently, it effectively improves the material's toughness, crack resistance, and overall structural stability. This research focused on the formulation design, process optimization, and microscopic mechanism analysis of cold-mixed epoxy asphalt. It provided effective solutions and theoretical basis for developing cold-mixed epoxy asphalt with high toughness and ease of operation.]]></description>
      <pubDate>Tue, 28 Jul 2026 08:40:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2694111</guid>
    </item>
    <item>
      <title>Toughening mechanism of desulfurized rubber in epoxy asphalt: From molecular dynamics simulation to curing behavior</title>
      <link>https://trid.trb.org/View/2691416</link>
      <description><![CDATA[Epoxy asphalt exhibits outstanding mechanical strength and durability, while its inherent brittleness significantly restricts performance under low-temperature service conditions. The incorporation of crumb rubber has been recognized as a promising strategy to enhance toughness; however, the combined effects of rubber content and desulfurization degree on the curing behavior and toughening mechanism of epoxy asphalt remain insufficiently clarified. In this study, an integrated experimental–computational framework was employed to address this gap. Non-isothermal curing kinetics were applied to quantitatively characterize the curing behavior of epoxy asphalt systems with varying rubber contents and desulfurization levels, while molecular dynamics (MD) simulations were conducted to evaluate free volume evolution and molecular diffusion behavior. The results imply that increasing desulfurization level significantly reduces the apparent activation energy of curing by approximately 7%, owing to reduced crosslink density and enhanced interfacial diffusion. In contrast, moderate rubber content (10 wt%) promotes curing efficiency and molecular mobility, whereas excessive rubber loading leads to chain entanglement and domain aggregation, resulting in increased curing resistance and delayed gelation. Within the experimental scope, a combination of moderate rubber content (10 wt%) and a relatively high desulfurization level (ML40) provides a favorable balance between curing efficiency and toughening performance. These findings offer quantitative guidance for the rational design of rubber-modified epoxy asphalt systems.]]></description>
      <pubDate>Wed, 22 Jul 2026 09:06:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691416</guid>
    </item>
    <item>
      <title>Toughness effects and microscopic mechanisms of natural nanotube on epoxy asphalt</title>
      <link>https://trid.trb.org/View/2691300</link>
      <description><![CDATA[Epoxy asphalt (EA) with a continuous epoxy resin phase is widely used in the construction of long-span orthotropic deck bridges. However, the inherent brittleness of epoxy resin often causes fatigue crack propagation in bridge surfacings under long-time service conditions. Natural halloysite nanotubes (HNTs) have been extensively utilized as toughening agents to improve the fracture resistance of epoxy resins. In this study, HNTs were employed to enhance the toughness of EA. The workability of uncured EA/HNT nanocomposites was evaluated through rotational viscosity (RV) measurements. Comprehensive characterization of cured EA systems included phase-separated morphology analysis, thermal stability assessment, evaluation of viscoelastic properties, mechanical performance testing, and characterization of HNT dispersion. Key finding revealed that HNT reduces the viscosity of epoxy asphalt during curing, thereby extending the workability window. The viscosity of epoxy/HNT nanocomposites increases with nanotube loading. Due to the nanoscale dimensions of HNTs, individual nanotubes are difficult to resolve directly under LSCM. However, their regulatory effect on the phase structure is indirectly confirmed by the significant refinement of asphalt domain sizes. HNT incorporation significantly improved EA thermal stability at higher loadings (≥ 1 wt%). The addition of HNTs enhanced the storage modulus across both the glass transition and rubbery plateau regions, while reducing the damping ability and glass transition temperatures (Tgs) of both asphalt and epoxy phases, with Tg values decreasing progressively with higher HNT concentrations. 0.5 wt% HNT loading achieved optimal mechanical property improvements, increasing tensile strength by 31%, elongation at break by 17%, and toughness by 38%.]]></description>
      <pubDate>Fri, 17 Jul 2026 10:09:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691300</guid>
    </item>
    <item>
      <title>The Influence of Secondary Forming on Delayed Fracture Behavior at Sheared Edges</title>
      <link>https://trid.trb.org/View/2684143</link>
      <description><![CDATA[The evaluation of delayed fracture resistance is one of the major issues for the application of high strength steel sheets to automotive parts. We are proposing a method for evaluating delayed fracture resistance using the four-point bending test specimen. The purpose of this study is to clarify the effect of the strain by secondary forming on the sheared edge delayed fracture resistance of the ultra-high strength steel sheets. The material used in this study is a martensitic steel sheet with a tensile strength of 1470MPa. The specimens were shear‑blanked and subsequently subjected to secondary forming, either tensile deformation by stretching or compressive deformation by deep drawing. The delayed fracture resistance was investigated by conducting immersion tests using four-point bending test specimens in a solution of 0.1%NH₄SCN+McIlvaine buffer for 96 hours. It was suggested that the small amount of secondary forming could improve the delayed fracture resistance because of the stress alleviation of residual stress by shearing. However, the delayed fracture resistance was deteriorated when the forming strain is too large because of the accumulated damage and heterogeneity on the edge surface. The variation of delayed fracture resistance by secondary forming amount was discussed by the combination of stress alleviation and damages on the sheared edge.]]></description>
      <pubDate>Tue, 23 Jun 2026 13:53:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2684143</guid>
    </item>
    <item>
      <title>Laboratory–field correlation of asphalt mixture fracture toughness: Weibull–GMTS prediction of field mode-II from Laboratory mode-I data</title>
      <link>https://trid.trb.org/View/2674621</link>
      <description><![CDATA[Particularly under low-temperature stress situations, asphalt mixture fracture resistance in field condition often differs from lab results. These differences result from changes in environmental exposure, variations in compaction, and material heterogeneity, hence a strong predictive model is required to link laboratory results into dependable field estimates. To predict fracture toughness discrepancies between laboratory and field conditions, this study creates a probabilistic model combining the Weibull statistical distribution and the Generalized Maximum Tangential Stress (GMTS) criterion. On asphalt specimens made under controlled laboratory conditions as well as on core samples taken from in-service pavements, Semi-Circular Bend (SCB) tests were performed. Mode I and Mode II were used to assess fracture toughness at a critical temperature of −6°C, reflecting field thermal stresses. While the GMTS criterion introduces a correction factor for laboratory-to-field extrapolation, the Weibull model provides a statistical assessment of fracture resistance variability. Accordingly, the proposed framework constitutes a semi-mechanistic, data-driven transfer model that combines fracture-mechanics principles with Weibull statistics, rather than a purely empirical curve-fitting approach. The results showed that field-compacted mixtures exhibited up to about 50 % lower fracture toughness than laboratory-compacted specimens, particularly in the binder course under Mode I loading, therefore stressing the effects of field-specific compaction and aging. High accuracy in predicting field fracture characteristics was shown by the suggested Weibull GMTS framework, which provides an efficient method to maximize asphalt pavement design and reduce dependence on thorough field testing.]]></description>
      <pubDate>Wed, 17 Jun 2026 12:23:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2674621</guid>
    </item>
    <item>
      <title>Multi-factor analysis and machine learning prediction of low-temperature fracture behavior in steel slag asphalt concrete under thermal-oxidative aging</title>
      <link>https://trid.trb.org/View/2677791</link>
      <description><![CDATA[Replacing natural aggregates with recycled Basic Oxygen Furnace Slag (BOFS) in Steel Slag Asphalt Concrete (SSAC) is a sustainable practice. Nevertheless, studies on the long-term thermo-oxidative aging effect on the low-temperature fracture behavior of SSAC, especially under complex mixed-mode loading, are still lacking. To address this, the present study systematically investigates the low-temperature fracture performance of SSAC under thermo-oxidative aging by integrating multifactor coupled experiments, machine learning prediction, and SHapley Additive exPlanations (SHAP) analysis. The results indicate that thermo-oxidative aging leads to a reduction in the Fracture Toughness (FT) and Fracture Energy (FE) of SSAC; however, the high angularity and high roughness of BOFS mitigate the deterioration process effectively through mechanical interlock. Specifically, under different fracture modes, the FT of Full-proportion BOFS Asphalt Concrete (SAC) is 30.2–44.2% higher than that of conventional asphalt concrete. After 7 days of thermo-oxidative aging, the degradation rate of FT for SAC (12.7–24.1%) is generally lower than that of conventional asphalt concrete (17.2–37.4%). In addition, among the 13 evaluated machine learning models, the Gradient Boosting model exhibits the best prediction performance, with R2 values of 0.932 for FT and 0.979 for FE. SHAP interpretability analysis reveals that fracture mode (SHAP value range ±0.3985) and test temperature (SHAP value range ±6.21) are the most influential factors affecting FT and FE, respectively. These findings are expected to provide valuable insights for the design of sustainable SSAC pavements for cold-climate applications.]]></description>
      <pubDate>Wed, 17 Jun 2026 12:23:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2677791</guid>
    </item>
    <item>
      <title>Assessment of the fracture performance of CR-modified bituminous mixtures enhanced with a reactive polymer using SCB test and image-based crack analysis</title>
      <link>https://trid.trb.org/View/2680382</link>
      <description><![CDATA[Modification of asphalt pavements with various additives has become an inevitable situation in order to resist the increasing traffic conditions and the corrosive effects of the environment for a longer period of time. In this study, the effect of the use of crumb rubber (CR) obtained from waste vehicle tyres in combination with a reactive polymer (B2Last) on fracture performance of bituminous mixtures was investigated by semicircular bending (SCB) test. The performance of CR+B2Last combinations was also compared with the widely used styrene-butadiene-styrene (SBS) modification. This study also examines fracture formation in hot mix asphalt using a U-Net-based image processing approach. It was found that B2Last used with CR realised the polyurethane reaction after short-term aging and was compatible with the bituminous mixture. 8%CR modification showed similar performance with 4% SBS modification, while the use of 2%B2Last in combination with 8%CR significantly increased the effectiveness of CR and offered much better fracture resistance than 4%SBS modification. With the U-net architecture, the crack area and propagation were successfully determined, and it was also found that there was a high correlation between these determined areas and SCB parameters.]]></description>
      <pubDate>Wed, 17 Jun 2026 12:23:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2680382</guid>
    </item>
    <item>
      <title>Polyvinyl Alcohol Fiber-Modified Resin-Based Microsurfacing: Toughness and Durability</title>
      <link>https://trid.trb.org/View/2675543</link>
      <description><![CDATA[The purpose of this study is to improve the toughness and durability of resin-based microsurfacing. SK70# asphalt, cationic emulsifier, water-based resin polymer system, basalt and limestone aggregates, and polyvinyl alcohol (PVA) fibers were used as raw materials. Two types of PVA fiber modified resin-based microsurfacings were prepared. The critical bending strain energy density, impact toughness, and tensile fracture energy were tested through toughness tests and the digital image correlation method. Moreover, the toughening effect of PVA fiber on microsurfacing was comprehensively evaluated. The evolution law of PVA fiber modified resin-based microsurfacing properties was investigated based on the composite working condition and accelerated loading wear test. The results show that PVA fiber can effectively improve the toughness and durability of resin-based microsurfacing. Compared to resin-based microsurfacing, when the fiber content is 0.1%, the bending toughness, impact toughness, and tensile toughness of PVA fiber modified resin-based microsurfacing increase by 30%–70%. After undergoing composite aging conditions and seven freeze–thaw cycles, the texture depth of PVA fiber modified resin-based microsurfacing remains between 0.95 and 0.99 mm, with a water permeability coefficient of 0 and a wet wheel wear value of less than 540  g/m². The retention rate of toughness can reach over 84%, demonstrating excellent durability. After 50,000 wear times, the British Pendulum Number of the PVA fiber modified resin-based microsurfacing remains around 73, with a cumulative wear depth stabilized at 3.5 mm, indicating that it maintains good pavement performance.]]></description>
      <pubDate>Wed, 17 Jun 2026 12:23:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2675543</guid>
    </item>
    <item>
      <title>Study on the Low-Temperature Cracking Characteristics of Warm-Mix Steel Slag and Rubber Powder–Modified Asphalt Mixtures Using Acoustic Emission Technology</title>
      <link>https://trid.trb.org/View/2672643</link>
      <description><![CDATA[Based on the acoustic emission (AE) dynamic nondestructive testing technology, a semicircular bending test (SCB) was conducted on warm-mix steel slag rubber powder modified asphalt mixture (CR-WSAM) at −10°C and −20°C to monitor its crack evolution behavior throughout the process. The low-temperature cracking resistance of asphalt mixtures was evaluated using the Thermal Stress Restrained Specimen Test (TSRST). By analyzing the fracture energy and AE characteristic parameters (e.g., ring count, amplitude, energy frequency) of SCB, its anticracking performance and damage evolution law were revealed. This study found that the significant increase in the cumulative energy of the acoustic emission signal and the increase in the number of RA signals indicate that the high strength and excellent surface morphology of steel slag enhance the interlocking effect between aggregates inside the mixture and improve the adhesion between asphalt and aggregate interfaces such that the energy release during crack propagation is effectively limited. The addition of SDYK warm-mix agent further improves the viscosity flow characteristics of asphalt, enhances the adhesion between asphalt and aggregate, and reduces the mixing temperature, which is manifested in the delay of the acoustic emission frequency peak and the increase in the proportion of high-frequency signals. In addition, as the temperature decreases, the growth rate in the ringing count in the acoustic emission characteristic parameters accelerates, and the peak amplitude increases significantly, indicating that the material gradually changes from a viscoelastic state to a highly elastic state; the anticracking performance of the four asphalt mixtures is ranked as follows: CR-WSAM > CR-HSAM > CR-WSBAM > CR-HSBAM.]]></description>
      <pubDate>Fri, 15 May 2026 09:18:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672643</guid>
    </item>
    <item>
      <title>Predicting the fracture temperature of asphalt mixtures under wet-dry cycles: An SCB test-based framework</title>
      <link>https://trid.trb.org/View/2670520</link>
      <description><![CDATA[Wet-dry cycles induced by precipitation triggers moisture damage in asphalt layers and accelerates thermal cracking of asphalt mixtures. Thermal cracking resistance is closely associated with the fracture temperature of asphalt mixture. So, the effects of wet-dry cycles on the low-temperature fracture toughness and energy were investigated through semi-circular bend (SCB) test. Based on the SCB tests across various temperatures (from −30 °C to 25 °C), a novel framework for predicting the fracture temperature was developed by integrating the experimental results with finite element (FE) method. A conversion coefficient was defined to convert the SCB flexural strength to the direct tensile strength for the thermal stress restrained specimen test (TSRST). The fracture temperatures of asphalt mixtures subjected to the wet-dry cycles were predicted. Results indicate that wet-dry cycles result in a reduction of the fracture toughness and fracture energy. With a high number of repetitions, even short-term immersing cycles can induce severe moisture damage in asphalt mixtures. The fracture energy is more susceptible to each change of wet-dry conditions. The conversion coefficient of 2.28 is determined for dense mixture. Fracture temperatures of asphalt mixtures are accurately predicted, wet-dry cycles result in an increase in the fracture temperature of asphalt mixtures, with frequent short-term immersion cycles exerting a significant influence on this property. This approach is particularly valuable for evaluating the low-temperature performance of in-service asphalt layers that have undergone moisture damage and aging.]]></description>
      <pubDate>Wed, 13 May 2026 09:33:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2670520</guid>
    </item>
    <item>
      <title>Evaluation of mixed mode I/II fracture behavior of asphalt concretes containing polyvinyl alcohol and coconut fibers</title>
      <link>https://trid.trb.org/View/2666230</link>
      <description><![CDATA[This research investigated the fracture resistance of hot mix asphalt (HMA) mixtures reinforced with polyvinyl alcohol (PVA) and coconut fibers under varying temperatures and fiber contents. The mixtures were prepared with fibers of a constant length of 12 mm and contents of 0.1 %, 0.2 %, and 0.3 % by total weight. We conducted fracture tests on Semi-Circular Bend (SCB) specimens at temperatures of −5°C, −15°C, and −25°C under pure mode I, pure mode II, and mixed-mode I/II loading. A key novelty of this study lies in the dual comparison of synthetic PVA fibers and natural coconut fibers, highlighting their different contributions to fracture toughness and fracture energy under multiple loading and at different temperatures. The results demonstrated that both PVA and coconut fibers significantly enhanced the fracture resistance of the HMA mixtures. The optimal fiber content was determined to be 0.1 % for PVA and 0.2 % for coconut fibers, as higher contents resulted in a decline in both fracture toughness and fracture energy. A decrease in test temperature led to an increase in fracture toughness for both control and fiber-reinforced samples, but it simultaneously caused a reduction in fracture energy. Furthermore, the fracture parameters were significantly influenced by the loading mode. For both fiber types, the greatest relative enhancement in fracture toughness occurred under pure mode II loading at −15 °C when compared with the control mixture, whereas at −25 °C, the most significant relative improvement was observed under pure mode I loading. Finally, in terms of both fracture energy and fracture toughness, coconut fibers outperformed PVA ones, making them the better choice for reinforcing asphalt mixtures subjected to cold climates and complex loading conditions.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2666230</guid>
    </item>
    <item>
      <title>An SBR-based toughness enhancement for high modulus recycled asphalt binder</title>
      <link>https://trid.trb.org/View/2668680</link>
      <description><![CDATA[To overcome the high brittleness at low temperatures and insufficient fatigue resistance at intermediate temperatures for high modulus recycled asphalt binder, styrene-butadiene rubber (SBR), a material with high flexibility, was attempted in this study as a modifier for performance enhancement. In this research, fluorescence microscopy was first employed to verify the uniform dispersion of SBR within high modulus recycled asphalt binder at the microscopic level. Meanwhile, a 40 % reduction in the S-value and a 25 % increase in the creep rate were observed in bending beam rheometer tests with the addition of 6 % SBR for high modulus recycled asphalt binder compared to HMRAB. Also, a dynamic shear rheometer-based G-R parameter was obtained to evaluate the cracking risks for asphalt binders. In addition, yield strain at failure and fatigue life were found to increase with the increase of SBR content for SBR modified high modulus recycled asphalt in linear amplitude sweep tests. Further, a significant (39 %) increase in fracture energy density was observed for SBR modified high modulus recycled asphalt with the addition of 6 % SBR using binder fracture energy tests. It can be concluded that higher ductility at low temperatures and better toughness at intermediate temperatures, and thus enhanced cracking resistance were indeed obtained with the addition of SBR for high modulus recycled asphalt binder.]]></description>
      <pubDate>Mon, 11 May 2026 08:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2668680</guid>
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