<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Triaxial creep test and damage model study of coarse-grained materials from red-bed soft rocks under freeze–thaw cycles: A multiscale analysis</title>
      <link>https://trid.trb.org/View/2636296</link>
      <description><![CDATA[Red-bed soft rocks are widely distributed worldwide, including in high-altitude regions like the eastern Qinghai-Tibet Plateau. Coarse-grained materials (CGMs) derived from them have been increasingly used as filling materials for subgrades subjected to seasonal freeze–thaw cycles. However, their creep behaviour in climatic conditions, especially under freeze–thaw cycles, has not been studied despite being crucial for analysing the long-term performance of subgrades. In this study, comprehensive triaxial creep tests were conducted on red-bed soft rock CGMs, manipulating the gravel content, water content, and the number of freeze–thaw cycles. Moreover, X-ray CT tests were carried out to provide insights from the mesoscopic perspective. The results demonstrated that the creep behaviour of red-bed soft rock coarse-grained materials occurred in four distinct stages. As the gravel content increased, the creep deformation at various stress levels first decreased and then increased, showing the same trend in its effect on long-term strength. A higher initial water content led to a greater creep deformation and lower long-term strength. The freeze–thaw cycles significantly affected creep behaviour, expanding and linking internal pores while fragmenting large particles. The grey relational analysis findings revealed a robust link between the long-term strength and maximum pore radius, and changes in mesostructure sped up macroscopic mechanical properties loss. Additionally, an extended Nishihara model of red-bed soft rock CGMs considering the effects of F-T cycles and sustained stress-induced damage was proposed. The proposed model exhibits a good fit to the experimental data across all creep stages, with its parameters directly derived from the data.]]></description>
      <pubDate>Wed, 04 Feb 2026 16:28:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2636296</guid>
    </item>
    <item>
      <title>Asphalt concrete subjected to long-time loading at low temperatures – Deviations from the time-temperature superposition principle</title>
      <link>https://trid.trb.org/View/2606078</link>
      <description><![CDATA[The article presents the observed deviations from the time-temperature superposition principle of asphalt concretes, tested in the bending beam creep test at low temperatures for a long time of loading. In almost all tested asphalt concretes, deviations appeared after 500 s of loading at the temperature of −10 °C. Some types of bitumen presented deviations at other temperatures – usually the harder the grade of the bitumen, the higher was the temperature of appearance of deviation. The article investigates also the impact of the following factors on the described deviations: type of bitumen, assumed time of loading and level of loading.]]></description>
      <pubDate>Mon, 24 Nov 2025 10:23:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2606078</guid>
    </item>
    <item>
      <title>Indentation creep test: A novel approach for characterizing asphalt viscoelasticity</title>
      <link>https://trid.trb.org/View/2550473</link>
      <description><![CDATA[The viscoelastic properties of asphalt critically determine pavement structural stiffness and service life by governing deformation behavior and load-carrying capacity. With the development of various novel modified asphalt materials, current testing methods, such as the Dynamic Shear Rheometer (DSR) test and the Bending Beam Rheometer (BBR) test, face a limitation that a standard sample may be inadequate to cover a representative volume element (RVE) when evaluating the viscoelasticity of modified asphalt. To address the limitation, this study proposes a cost-effective indentation creep test for efficient viscoelastic characterization. Utilizing dimensional analysis and elastic-viscoelastic correspondence principles, a theoretical model was es26tablished, demonstrating that indenter displacement governs characteristic creep compliance, independent of device geometry. A prototype device was developed to evaluate prevalent asphalt materials, with experimental results validating the theoretical model and revealing key influencing factors. Furthermore, comparative analysis confirmed the indentation creep test’s equivalence to DSR and BBR tests in assessing complex modulus and creep stiffness. This innovative indentation creep test offers practical advantages for asphalt viscoelastic characterization, with broad engineering application potential.]]></description>
      <pubDate>Fri, 20 Jun 2025 11:58:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2550473</guid>
    </item>
    <item>
      <title>Laboratory-to-field correlation and validation of performance specifications for bituminous mixtures</title>
      <link>https://trid.trb.org/View/2503034</link>
      <description><![CDATA[The study emphasizes the significance of performance testing and specification in pavement design, for ensuring resilience and durability. The present study investigates the correlation and association between different compaction methods (in laboratory, plant, and field) and their influence on pavement performance, focusing on permanent strain (PS, in %) and cracking tolerance index (CTIndex) values. Field test sections were constructed on NH-330A (National Highway) of India to validate the Marshall mixtures initial threshold specification. Performance test results indicate that in the dynamic creep test, laboratory compacted samples show slight variations in PS (%) values as compared to plant-compacted samples. However, there was no significant difference in the variation (p-value < 0.05). However, field cores exhibited significantly (p-value > 0.05) higher PS (%) values compared to both laboratory and plant compacted samples. Further, in the IDEAL-CT test, the laboratory compacted samples have slightly lower CTIndex values. In contrast, the plant compacted samples generally have higher CTIndex values but still less than those of field cores. However, the t-test revealed no significant difference between laboratory, plant and field compacted specimens in the IDEAL-CT test since p-value < 0.05. The higher values of PS (%) and CTIndex observed in field cores can be attributed to different sample thickness and compaction methodologies. Despite the variations, the strong positive correlation (R² > 0.758) between laboratory samples and field cores for BC-1 and DBM-2 confirms that initial performance criteria are appropriate and justified.]]></description>
      <pubDate>Thu, 13 Mar 2025 09:24:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2503034</guid>
    </item>
    <item>
      <title>Evaluating the distress resistance of asphalt mixtures using scalar modulus</title>
      <link>https://trid.trb.org/View/2447695</link>
      <description><![CDATA[Although numerous parameters have been proposed to effectively evaluate the distress resistance of asphalt mixtures, their application is often limited by complex testing procedures. To address this problem, this work correlates the scalar modulus (SM) with key material properties such as the creep compliance rate (Cr), fracture energy (FE) and dissipated creep strain energy (DCSE), and these key material properties are closely related to pavement distress. The scalar modulus was conceived as an essential foundational ‘seed’ property, envisioned as a pivotal link that interconnects various performance characteristics of asphalt mixtures. The SM of materials can be determined using simple creep tests or relaxation tests, which reduces both the cost and time associated with testing. To streamline this process further, a master curve that correlates SM to temperature is proposed. By knowing the reference scalar modulus (SM at 50 °F) of materials, the SM of materials at other temperatures can be determined using the master curve. This study is supported by extensive test data that cover a variety of testing conditions, aging states, both modified and unmodified asphalt binders, and different mix designs. Based on these data, the relationships of SM with Cr, FE and DCSE are established. It is shown Cr, FE and DCSE increase with the decrease of SM, and at a given SM, the values of Cr, FE and DCSE for asphalt mixtures with unmodified binder are larger than those for asphalt mixtures with modified binder. These results affirm that the scalar modulus is a reliable metrics for evaluating the performance of asphalt concrete. Based on this work, once the SM at one reference temperature, the corresponding Cr, FE, and DCSE at any temperature can be obtained directly. Thus, compared with other methods on estimating the distress resistance of asphalt mixtures, using SM can save the time and cost for testing considerably.]]></description>
      <pubDate>Fri, 22 Nov 2024 14:57:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/2447695</guid>
    </item>
    <item>
      <title>Wheel-rail contact wear analysis on curved lubricated track for heavy haul locomotive studies</title>
      <link>https://trid.trb.org/View/2434983</link>
      <description><![CDATA[The effect of lubrications on a curved track to heavy-haul wheel-rail contact wear is studied. To analyse wheel-rail contact wear damage due to existing high-adhesive AC locomotive, a methodology for investigation is proposed, and the locomotive models are required to run at 20 km/h under maximum traction efforts, and the simulations include a DC locomotive for comparison. An extended creep force model, which was developed by Polach and has been widely used for the wheel-rail contacts under dry and wet conditions with variable friction coefficients, is further extended to apply for the typical low-coefficient-friction modifier, oil, and grease lubricant conditions. The wear models from two pairs of wheel-rail materials are used to predict the wear rates, and the wear numbers T? are presented for discussions. The simulations show that the lubricants significantly reduce the wheel-rail contact wear.]]></description>
      <pubDate>Thu, 17 Oct 2024 09:15:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2434983</guid>
    </item>
    <item>
      <title>Equivalent Principle of Temperature-Aging for Asphalt Mixture Based on Creep Test</title>
      <link>https://trid.trb.org/View/2282862</link>
      <description><![CDATA[Asphalt mixture is a kind of simple thermal rheological material. The main mechanics behavior character of viscoelastic material is its time dependence, which lies in the existence of the interior timepiece or the characteristic time influencing by many factors. The free volume theory of material viscosity is usually used to study the characteristic time. Based on this theory, this paper deduced the time-temperature equivalent relation of Williams-Landel-Ferry (WLF) equation. Aging influences the viscosity as well. Through the creep test, this paper deduced the time-temperature, time-aging, temperature-aging equivalent equation. The equivalent principle also can be used in asphalt, modified asphalt and modified asphalt mixture.]]></description>
      <pubDate>Mon, 07 Oct 2024 08:37:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2282862</guid>
    </item>
    <item>
      <title>Assessing High-Temperature Performance of Asphalt-Filler Mastic System Treated with Micro-Nano Filler Combinations</title>
      <link>https://trid.trb.org/View/2410725</link>
      <description><![CDATA[This work evaluates the performance of asphalt-filler mastic treated with a combination of inert-active fillers at high temperature. Inert filler does not react with asphalt, whereas active filler actively participates in a chemical reaction with asphalt. This study utilized a viscosity grade (VG)-30 asphalt, basalt stone dust (B), hydrated lime (HL), and nano hydrated lime (NHL) as fillers for asphalt-filler mastic preparation. The dosages of HL and NHL fillers were varied as 0%, 5%, 10%, 15%, and 20% by weight of VG-30. Filler/binder ratios of 0.6 to 1.2 were considered with different filler combinations (B, B-HL, B-NHL) for the production of 36 mastic types. The high-temperature performance of the asphalt-filler mastic was investigated using shear creep and multiple creep-recovery tests. Further, this study evaluated the properties of the fillers which were most influential on the permanent deformation behavior of mastic using grey relational analysis. The findings signify the beneficial effects of NHL over HL in improving the ability of mastic to withstand permanent deformation. Also, mastic treated with NHL was found to be less susceptible to high stress levels than mastic treated with HL. It was also found that the amount of active filler can be reduced by 5% (by weight of asphalt) by using NHL instead of HL to achieve the equivalent high-temperature performance of mastic. Specific surface area and average particle size were found to be the most two influential properties of filler that significantly influenced the high-temperature performance of the asphalt-filler mastic.]]></description>
      <pubDate>Mon, 12 Aug 2024 11:35:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2410725</guid>
    </item>
    <item>
      <title>Experimental study on creep-fatigue damage of hot central plant recycling asphalt mixture containing high RAP</title>
      <link>https://trid.trb.org/View/2403606</link>
      <description><![CDATA[The objective of this study is to delve into the nonlinear damage evolution mechanism of hot central plant recycling asphalt mixture under the influence of creep-fatigue interaction. A predictive model for lifespan, considering the interaction of temperature and load, was developed. Dynamic creep tests were conducted at different temperatures to assess the creep effect of the asphalt mixture under actual road temperature conditions. The investigation began by acknowledging the material's viscoelastic properties, thereby deriving the loss compliance value - a key indicator of temperature effects - using an equivalent conversion factor and a viscoelastic mechanics model. This allowed for the incorporation of creep behavior into the load system. Furthermore, to analyze the nonlinear damage mechanism and fatigue prediction mechanism, direct tensile fatigue tests were performed at different temperatures and different stress levels. The fatigue damage evolution law of hot central plant recycling asphalt mixture containing high RAP considering the creep effect was revealed, and the fatigue life evaluation method under the combined action of temperature and stress level was proposed. The results show that the fitting degree of the time-temperature conversion equation and the viscoelastic mechanics model to the test data is more than 0.9, and the derived loss compliance value better captures the creep effect. Based on the nonlinear creep-fatigue damage model, the damage law of high-RAP hot central plant recycling asphalt mixture was identified. The optimized fatigue life prediction model fully considers the combined effect of temperature and stress level and analyzes the influence parameters of the real state of pavement fatigue. The prediction accuracy is within the requirements of engineering applications. The model's predictive accuracy meets the criteria for engineering applications, enhancing the multifaceted damage coupling analysis approach for hot central plant recycling asphalt mixture and predict the service life of recycled pavements under complex conditions, establishing a groundwork for the prediction and assessment of long-lasting recycled pavements.]]></description>
      <pubDate>Fri, 09 Aug 2024 15:31:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2403606</guid>
    </item>
    <item>
      <title>Viscoelastic Mechanical Properties of Crumb Rubber Modified Asphalt Mixture</title>
      <link>https://trid.trb.org/View/2203654</link>
      <description><![CDATA[Crumb rubber modified asphalt (CRMA) mixture is a typical viscoelastic material. The pavement made from CRMA mixture has anti-skid surfaces and the pavement is good in reducing the traffic noise. Moreover, building the road with CRMA mixture is important in controlling the pollution caused by a large amount of discarded tires. In order to study the rheological characteristics of CRMA mixture, a series static creep tests for the material has been performed at –15 °C, 0°C, 15 °C, 30 °C and 45 °C respectively. The experimental results indicate that the Burgers model is good in simulating the viscoelastic characteristics of CRMA mixtures. Viscoelastic parameters and time dependence of creep stiffness modulus can be obtained from the simulation of the experimental data. The result shows that creep stiffness modulus decreases rapidly at the initial stage of loading, then the rate of change decreases, and finally creep stiffness modulus approaches to a stable value at the end of loading.]]></description>
      <pubDate>Sat, 03 Aug 2024 16:26:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2203654</guid>
    </item>
    <item>
      <title>Viscoelastic Analysis of Asphalt Pavement Using a Regularized Interconversion Technique between Creep and Relaxation</title>
      <link>https://trid.trb.org/View/2203644</link>
      <description><![CDATA[This study illustrates a regularized method in the viscoelastic analysis of asphalt pavement based on time-domain creep tests. The method is capable of overcoming the ill-posedness of interconversion between creep compliance and relaxation modulus by solving a Volterra integral equation of second kind with regularization. The discrete data of relaxation modulus is calculated by the regularized method and fitted to the generalized Maxwell model. After the viscoelastic parameters of asphalt mixtures are obtained, the nonlinear finite element model of pavement is developed and the computed results indicate that the viscoelastic mechanical responses of pavement are greatly affected by temperature and loading time. The results of this study are expected to be utilized to predict and validate the distress of asphalt pavement in the design and maintenance periods.]]></description>
      <pubDate>Sat, 03 Aug 2024 16:26:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2203644</guid>
    </item>
    <item>
      <title>Creep damage evolution process of asphalt binder based on viscoelastic characteristics</title>
      <link>https://trid.trb.org/View/2390960</link>
      <description><![CDATA[The creep damage evolution of asphalt binder plays a significant role in investigating the formation mechanism of rutting. The rutting is the common distress at high temperatures for asphalt pavements. However, the reliability of existing creep damage parameters is under questioned, and these parameters cannot accurately illustrate the change of intrinsic microstructure for asphalt binder. In this paper, a new test protocol was given access to study the evolution of viscoelastic parameters during creep damage. It was completed by inserting the frequency sweep during creep test. The frequency sweep curve clusters were fitted by the generalized Kelvin-Voigt model for obtaining the change law of model parameters. Based on the change law and sensitivity analysis of model parameters, (E2 + E3)/2 was proposed as the creep damage variable. According to the curve of (E2 + E3)/2 versus loading time, two stages during the creep test could be identified: an approximate constant value in phase Ⅰ and a linear decrease in phase Ⅱ. Intrinsic differences about creep property of binders could be determined by this new proposed parameter. Above results not only ensure better understanding of the creep damage mechanism of binders, but also lay the theoretical foundation on predicting the anti-rutting performance of binders.]]></description>
      <pubDate>Mon, 24 Jun 2024 09:24:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2390960</guid>
    </item>
    <item>
      <title>The scalar modulus: A novel parameter for predicting creep properties of asphalt mixtures</title>
      <link>https://trid.trb.org/View/2361276</link>
      <description><![CDATA[In this paper, the authors introduce a novel material parameter termed the 'scalar modulus,' conceived through the expansion of the elastic-viscoelastic correspondence principle. The extended principle and associated transformations open new avenues for applying this framework under non-constant strain rate conditions, particularly in scenarios like creep test. Through a combination of rigorous experimental observations and numerical analysis, the authors establish a crucial relationship between the creep rate/creep compliance rate and the 'seed property' known as the scalar modulus. This relationship proves to be distinctive for diverse asphalt compositions, temperatures, and loading conditions, effectively delineating the material's internal states. To validate the versatility of this novel concept, the authors conducted an extensive series of experiments on various asphalt concrete mixtures with varying aggregate types, gradation, air void content, binder content, and aging durations. The experimental approaches to obtain the scalar modulus encompasses Superpave IDT tests, uniaxial static creep tests under tension and compression, as well as both destructive and non-destructive creep tests. By thoroughly examining the scalar modulus and characterizing the material behavior under varying composition and conditions, the authors gain crucial insights into its creep behavior and its reaction to external mechanical loads.]]></description>
      <pubDate>Fri, 26 Apr 2024 09:01:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2361276</guid>
    </item>
    <item>
      <title>Probabilistic characterisation of transition points in three-stage permanent deformation curves using Bayesian inference approach</title>
      <link>https://trid.trb.org/View/2310491</link>
      <description><![CDATA[Multiple specimens are tested to evaluate their rutting propensity by applying static and dynamic creep loads until a three-stage permanent deformation curve is obtained. This three-stage curve consists of two transition points, i.e. one from the primary to the secondary stage and the other one from the secondary to the tertiary stage of deformation. Due to replication, these transition points behave like random variables rather than deterministic. This stochasticity in the transition points is characterised by the Probabilistic -Stress-Number of cycles (P-S-N) approach. A power law model is used to describe the trajectory of transition points with respect to the input stress level. The probabilistic nature of these power law parameters is characterised by the Bayesian approach rather than the classical approach because the latter considers distribution parameters to be constant and does not reflect the replicate stochasticity. Posterior distributions are determined based on data translated likelihood method. Based on the posterior distributions of the data sets, obtained power law trajectories at various reliability levels, ranging from highest to lowest, are constructed. One advantage of this approach is its capability to extrapolate secondary transition points (Flow number or Flow time) when they cannot be readily obtained under desired testing conditions.]]></description>
      <pubDate>Mon, 04 Mar 2024 14:29:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310491</guid>
    </item>
    <item>
      <title>Time-Temperature-Stress Equivalent Characteristics and Nonlinear Viscoelastic Model of Asphalt Mixture under Triaxial Compressive Stress State</title>
      <link>https://trid.trb.org/View/2292607</link>
      <description><![CDATA[To objectively characterize the time-temperature-stress equivalence of viscoelastic properties of asphalt mixture, the triaxial compressive creep test was carried out on an AC-13 asphalt mixture under the conditions of different temperatures and stress states in this paper and the nonlinear variation law of creep deformation was obtained. According to the characteristics of similar creep curves and the principle of time-temperature equivalence, two methods were used to shift the creep compliance under different confining pressure, temperature, and axial stress conditions, and the change of temperature and stress shift factors with confining pressure were obtained; in addition, the creep compliance principal curve was fitted by the Prony series and its principal surface was established. On this basis, the multiple stress creep recovery test under different confining pressures was conducted to measure the parameters of Schapery’s nonlinear viscoelastic model and their variation law with the triaxial stress ratio was obtained, which accurately characterized the synergistic effect of confining pressure and axial stress.]]></description>
      <pubDate>Mon, 18 Dec 2023 08:46:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2292607</guid>
    </item>
  </channel>
</rss>