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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>Laboratory characterisation and mechanical performance of EAF slag and recycled rubber mixtures for transport infrastructure</title>
      <link>https://trid.trb.org/View/2768794</link>
      <description><![CDATA[Achieving sustainable transport infrastructure calls for materials that combine mechanical efficiency with environmental and economic viability. This study, developed within the framework of an ongoing Portuguese re-search project, examines the properties of granular mixtures composed of Electric Arc Furnace (EAF) slag and recycled tyre rubber, for potential implementation in road and railway structural layers. An extensive laboratory testing programme is underway, encompassing monotonic and cyclic triaxial tests to evaluate shear strength, resilient modulus and permanent deformation. It is demonstrated that slag-rubber mixtures can provide adequate strength and resilient behaviour for transport infrastructure support layers, provided the rubber content is kept below 5% by weight and the slag is processed to meet the particle size distribution limits specified in the relevant technical standards.]]></description>
      <pubDate>Fri, 18 Sep 2026 16:00:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2768794</guid>
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    <item>
      <title>Correlating continuous compaction measurement to plate load tests for quality assurance</title>
      <link>https://trid.trb.org/View/2709931</link>
      <description><![CDATA[Continuous compaction control (CCC) offers a promising alternative to conventional spot tests for earthwork quality assurance. However, establishing reliable correlations between intelligent compaction measurement values (ICMVs) and traditional stiffness metrics, such as the deformation modulus (Eᵥ₂) from static plate load tests (PLT), remains a challenge. This study investigated the influence of PLT plate size and vibratory roller type on these correlations through a series of full-scale compaction tests conducted on a granular soil bed. Two plate diameters (300 and 600 mm) and two rollers with different static linear loads (36 and 65 kg/cm) were employed. Sixteen ICMVs spanning acceleration-, mechanics-, and energy-based categories were computed and correlated with Eᵥ₂. The results showed that the 600-mm plate, despite producing lower Eᵥ₂ values, consistently yielded stronger correlations with the representative ICMVs. The lighter roller produced stronger correlations than the heavier roller, likely due to reduced contact loss and better alignment of measurement depths. Mechanics-based ICMVs performed best, with the vibration modulus (Evib) during the loading phase showing the strongest correlation (R up to 0.8). These findings confirm that Evib is a suitable indicator for compaction quality control, suggest that the larger plate is preferable for calibration purposes, and underscore the need for machine-specific calibration.]]></description>
      <pubDate>Fri, 18 Sep 2026 11:38:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2709931</guid>
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    <item>
      <title>Evaluation Method of Deformation Modulus of Subgrade Soils Considering Drainage Condition</title>
      <link>https://trid.trb.org/View/2113171</link>
      <description><![CDATA[In order to improve the accuracy of pavement structural design, we examined a method to accurately estimate the deformation modulus of subgrade soils. When designing the pavement structure by the theoretical design method, if the deformation modulus of the subgrade can be accurately estimated, pavement structure thicknesses can be determined reasonably with a limited budget. For this purpose, we developed a new testing method “CTX-BE test” by combining the method of cyclic triaxial test (standardized by Japanese Geotechnical Society [JGS0542]) with that of bender element test ([JGS0544]). In this study, a series of CTX-BE tests were conducted on Toyoura sand to investigate the method of setting the deformation modulus E and Poisson’s ratio ν necessary for pavement structural analysis. The CTX-BE test was performed under undrained and drained conditions, and the shear wave velocity Vs was measured by bender element transducers after the change of effective stress with stepwise cyclic triaxial loading. Based on a series of test results, we proposed a new method for evaluating the deformation modulus and Poisson’s ratio required for pavement structural design in consideration of drainage conditions of subgrade.]]></description>
      <pubDate>Thu, 28 May 2026 17:09:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113171</guid>
    </item>
    <item>
      <title>Detecting support modulus of curved railway tracks by a double-beam model using a moving test carriage</title>
      <link>https://trid.trb.org/View/2654647</link>
      <description><![CDATA[Curved tracks are prone to derailment, but have not been well treated. This paper establishes a theoretical framework for extracting rail-related vertical frequencies and track moduli of curved tracks subjected to a moving test carriage for the first time. The curved track is modeled as a double-beam system to represent both the rail and the supporting bridge structure, with an intermediate layer incorporated to simulate the effects of ballast and sleepers. Closed-form solutions for vehicle and contact responses are obtained via modal superposition. The contact acceleration spectrum, free from vehicle frequencies, enables clearer frequency identification. The rail-related vertical frequency, linked to track modulus, shows the highest identifiability, first appearing in the high-frequency range. The finite element method (FEM), validated by analytical solutions, is used for robustness analysis, leading to the following conclusions: (1) track modulus extraction is minimally affected by curvature radius, and support stiffness; (2) a medium vehicle speed of 20 m/s (72 km/h) offers a balance between efficiency and accuracy; and (3) in the presence of track irregularity and damping, track modulus can still be reliably retrieved.]]></description>
      <pubDate>Tue, 31 Mar 2026 16:35:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2654647</guid>
    </item>
    <item>
      <title>Evaluation of Elastic Modulus Evolution of Cold In-place Recycling during early curing</title>
      <link>https://trid.trb.org/View/2674285</link>
      <description><![CDATA[Cold in-place recycling (CIR) presents environmental and technical benefits by reusing existing asphalt pavement, reducing the use of virgin aggregates, and minimizing emissions during rehabilitation. Despite these advantages, aspects such as stiffness development, spatial variability, and temperature effects remain under-implemented in routine CIR quality control. This study evaluates the evolution of the elastic modulus in the CIR layer during early curing, using light weight deflectometer (LWD) tests under real construction conditions in Québec, Canada. Elastic modulus values were backcalculated with BackCAP software and corrected to a reference temperature of 25 °C to reduce variability associated with temperature differences. Tests were carried out at multiple time intervals (0, 1, and ≈24 hours) and locations, both longitudinally and transversely. Results showed an increase in elastic modulus over time, attributed to curing effects, and revealed spatial heterogeneity—especially across the width of the lane and at specific chainages. The outer wheel path consistently displayed higher stiffness, suggesting the influence of traffic-induced compaction. The findings reinforce the importance of spatially distributed modulus measurements and thermal correction for reliable assessment of mechanical performance at early ages. Integrating LWD testing and temperature-adjusted backcalculation into CIR quality control can improve assessment consistency. It is recommended to exclude the first 150 meters of the test section to account for equipment calibration zones. The ability to quantify modulus gain within 24 h enables agencies to optimize traffic-opening schedules and adjust compaction or moisture control, improving long-term pavement durability and reducing maintenance costs. Future research should apply advanced statistical methods to enhance the reliability and generalizability of recycled pavement performance assessments.]]></description>
      <pubDate>Thu, 12 Mar 2026 08:52:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2674285</guid>
    </item>
    <item>
      <title>Dynamic and Resilient Modulus of Frozen Soils</title>
      <link>https://trid.trb.org/View/2562009</link>
      <description><![CDATA[The dynamic and resilient modulus of frozen soils are pivotal parameters for assessing their mechanical properties under various loading conditions. This study characterizes the material properties of frozen soils, essential for transportation infrastructure, using modified AASHTO T 342 and 307 procedures. The dynamic modulus measures the soil’s ability to deform elastically under cyclic loading, while the resilient modulus reflects its capacity to recover from deformation. Influences such as freeze-thaw cycles, moisture content, and temperature play significant roles in these properties, with ice bonds in frozen soils breaking at different frequencies and temperatures, thus affecting mechanical behavior. This research modifies the Dynamic Modulus test procedure to determine the specific properties and behaviors of soil under low-temperature loads. Adjustments include utilizing different test equipment, sample preparation methods, and modifying test conditions (frequency, amplitude, and temperature) to replicate field conditions accurately. Comparative analyses were conducted using two moisture contents of sandy silt (ML), lean clay (CL), and fat clay (CH) to characterize the behavior of frost-susceptible subgrade soils. Understanding these moduli is crucial for designing and maintaining infrastructure in cold regions, ensuring the durability and safety of transportation networks. This knowledge enables better predictions of how frozen soils will respond under traffic loads, which is vital for engineering projects in challenging environments.]]></description>
      <pubDate>Tue, 27 Jan 2026 16:16:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2562009</guid>
    </item>
    <item>
      <title>Phase Angle at Constant Modulus in Polymer Modified Asphalts</title>
      <link>https://trid.trb.org/View/2652156</link>
      <description><![CDATA[While refinery asphalt production in Canada remains largely focused on processing heavy asphaltic crude oils from vast reserves in Alberta and Saskatchewan, the binder formulation used in Canadian roads is predominantly driven by economic and environmental considerations rather than availability of local, high-quality refinery-produced asphalts. This has led to increased use of Polymer Modified Asphalts (PMA), a variety of recycled materials, softening oils, and bio-sourced products to mention the most common. It has been demonstrated that the SuperPave™ specification in some cases is no longer able to effectively screen out poorly performing binders. In our previous work, we identified that phase angle measured at a prescribed magnitude of constant modulus can be a reliable and reproducible parameter to screen out poor performers. In elastomer modified asphalts however, the phase angle is no longer a simple function over a range of loading times. In some cases, the validity of time-temperature superposition principle is not warranted. This study demonstrated that phase angle at the magnitude of complex modulus of 8,967 kPa can be reliably determined in PMAs. Based on the experimental and scientific evidence presented here, phase angle at constant modulus is recommended as specification parameter also for PMAs.]]></description>
      <pubDate>Tue, 20 Jan 2026 11:16:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2652156</guid>
    </item>
    <item>
      <title>Synchronous strain and modulus sensing in asphalt layers via inclusion-matrix deformation mapping</title>
      <link>https://trid.trb.org/View/2597931</link>
      <description><![CDATA[Due to the viscoelastic behavior of asphalt mixtures, dynamic strain monitoring alone is insufficient to fully interpret asphalt pavement performance. This study presents a synchronous sensing method for dynamic strain and real-time modulus based on the deformation mapping theory between inclusions and the matrix. The method enables performance assessment of asphalt layers using fatigue-related indicators such as modulus degradation and energy dissipation. First, the theoretical mapping between the modulus ratio and strain ratio of embedded strain sensors and the host material was derived and validated through numerical simulations. Then, the specific deformation mapping behavior between the sensors and the asphalt matrix was analyzed and established. Based on this principle, a multi-modulus embedded strain sensor array was developed and experimentally evaluated for its ability to simultaneously capture dynamic strain and in-situ modulus in asphalt mixtures. The results demonstrate that the embedded strain sensors exhibit a clear deformation mapping relationship with the matrix, characterized by an S-shaped distribution. This mapping law enables the sensor array to synchronously monitor both strain and modulus. The maximum strain measurement error remains within 4.7 % across a wide range of temperatures (0 °C to 40 °C) and loading frequencies (0.2 Hz to 25 Hz), significantly outperforming single-sensor measurements. Additionally, the modulus measurement error is maintained within 16.8 % under the same temperatures and loading conditions. Future work will focus on reducing measurement errors by optimizing the coordinated distribution and matching of sensors with different moduli within the sensor array.]]></description>
      <pubDate>Thu, 23 Oct 2025 09:23:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2597931</guid>
    </item>
    <item>
      <title>Study on the Performance of High-Modulus Asphalt Based on Rheological Properties and Cracking Behavior</title>
      <link>https://trid.trb.org/View/2578198</link>
      <description><![CDATA[In this study, the road performance of high-modulus asphalt materials and their modification mechanism are systematically analyzed, aiming to achieve a balance between rutting resistance and cracking resistance. The modified composite asphalt materials are prepared using seven high-modulus modifiers(PRM,PRS,KPL, AFKCPT, AFKCZQ, RK300.3-1, RK300.3-2), and their performance is analyzed and compared against matrix asphalt (MA), rubber-modified asphalt (RMA), and styrene-butadiene-styrene (SBS)-modified asphalt. A multi-scale rheological evaluation system is adopted to assess the damage accumulation rate through linear amplitude scanning (LAS) tests, while large amplitude oscillation scanning test (LAOS) tests are used to characterize the structural response under large strain conditions. Additionally, a combination of pure linear amplitude scanning (PLAS) and Glover-Rowe (G-R) parameter tests is used to predict the cracking behavior of the high-modulus asphalt from a rheological perspective. Further, the cracking resistance evolution of the material is analyzed using three fracture-related methods: binder fracture energy (BFE), double-edged notched tensile (DENT), and improved direct tensile (DT) tests. The results reveal that high-modulus modification significantly improves the asphalt’s resistance to high-temperature deformation resistance but compromises its low-temperature ductility. Compared with the traditional asphalt materials, high-modulus asphalt exhibits a notably higher damage accumulation rate, which adversely affects its cracking resistance. Under large strain conditions, the interactions within the molecular network of high-modulus asphalt weaken, making its structure more prone to damage. Furthermore, high-modulus asphalt lacks sufficient flexibility and relaxation capability, resulting in a heightened risk of cracking. At lower temperatures, its becomes harder and more brittle, and traditional fracture toughness measures fail to accurately reflect its fracture properties. The three fracture test indices show a significant correlation with the surface energy parameters, confirming the dominant role of interfacial adhesion in determining the failure modes of the material. The multi-indicator evaluation system developed in this study offers essential technical support for designing high-modulus asphalt mixtures and holds significant engineering value for extending the service life of heavy-duty pavements.]]></description>
      <pubDate>Wed, 30 Jul 2025 16:23:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2578198</guid>
    </item>
    <item>
      <title>Layer Equivalency Factors and Deformation Characteristics of Flexible Pavements Test Data</title>
      <link>https://trid.trb.org/View/2561667</link>
      <description><![CDATA[This document is a supplement to Research Report 284-3, "Layer Equivalency Factors and Deformation Characteristics of Flexible Pavements." It contains the collection of graphs of the pressuremeter test and the corresponding regression curves for the hyperbolic stress-strain model performed during the course of the study reported in Research Report 284-3.]]></description>
      <pubDate>Mon, 21 Jul 2025 16:19:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2561667</guid>
    </item>
    <item>
      <title>Layer Equivalency Factors and Deformation Characteristics of Flexible Pavements</title>
      <link>https://trid.trb.org/View/2561668</link>
      <description><![CDATA[In this report, a method is developed for determining the equivalent thicknesses for different base courses, which will give the same pavement life expectancy. This study shows how the layer equivalents can be obtained from Texas Triaxial tests or from pavement pressuremeter tests or from Dynaflect tests. The procedures were developed after testing 11 pavement sections having four different types of base courses and subbase courses in the Beaumont District (District 20) in Southeastern Texas. Taking the sand and oyster shell base course as reference (layer equivalent of 1), it was found that the lime treated crushed sandstone had a layer equivalent of 0.68, the iron ore 1.17, and the select sand 1.29. This study permitted moduli of deformation to be obtained from the pressuremeter test, the Texas Triaxial test and the Dynaflect test coupled with the Russian equation. Comparisons between the various moduli are presented. This study used the cyclic pressuremeter test to determine the stress and strain level dependency of soil moduli and permanent deformation characteristics of the layers. This report includes the presentation of a procedure to determine the layer equivalents of base courses on the basis of Texas Triaxial tests. Examples of calculations are included.]]></description>
      <pubDate>Mon, 21 Jul 2025 16:19:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2561668</guid>
    </item>
    <item>
      <title>Maximising the benefits of current intelligent compaction technology for asphalt pavement construction: insights and implications for industry application</title>
      <link>https://trid.trb.org/View/2550870</link>
      <description><![CDATA[Intelligent compaction (IC) technology involves attaching an accelerometer to the vibratory drum of a roller to map the equivalent modulus of pavement layers (down to the influence depth) in real-time. The accelerometer data is analysed to produce various Intelligent Compaction Measurement Value (ICMV) parameters, categorised into 5 levels by the Federal Highway Administration. While Level 1 ICMVs, such as compaction meter value (CMV)) and compaction control value (CCV) can be calculated in real-time using only the accelerometer data, Level 3 ICMVs, such as roller-integrated stiffness (k_b) and vibratory modulus (E_VIB), require both accelerometer data and the position of the exciters. ICMVs are indices for equivalent stiffness of the layers in the roller influence depth, with the influence depth depending on the type and mass of the roller, amplitude and properties of the layer. IC technology is not widely adopted in Australia. According to a survey, the key reasons for this are a lack of knowledge about it, uncertainty regarding its accuracy and value, high initial costs, a shortage of trained operators and the absence of specifications for its use. Even where it is used, it is primarily for tracking roller pass counts and asphalt surface temperature, rather than for density estimation. As a result, the full potential benefits of a real-time monitoring system such as IC are not being realised. This study has 2 main objectives. First, it aims to gain a deeper understanding of the limitations of current IC technology in asphalt compaction, particularly its effectiveness as a reliable indicator of density. Second, it seeks to explore alternative methods that can be integrated with IC systems to enhance their overall efficacy.]]></description>
      <pubDate>Wed, 07 May 2025 13:46:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2550870</guid>
    </item>
    <item>
      <title>Determination of the Viscosity Modulus of Concrete Under Static-Dynamic Loading Regimes</title>
      <link>https://trid.trb.org/View/2407790</link>
      <description><![CDATA[The results of experimental and theoretical studies to determine the viscosity modulus of concrete under static-dynamic loading are presented. The considered model of concrete deformation is based on the plasticity theory of concrete and reinforced concrete of G.A. Geniev, whose deformation dependences are constructed taking into account the adopted static-dynamic loading regime. According to a specially developed and patented technique, the results of uniaxial tests of concrete prisms were obtained in a two-stage regime of their static-dynamic loading and the parameters of concrete deformation in time were experimentally determined, which allow experimentally to obtain the viscosity modulus of concrete of different classes. It is shown that the viscosity modulus of concrete and its dynamic strength depends not only on the class of concrete but also on the level of its static loading at the first stage. The results obtained are of interest for solving problems, the strength, and deformability of sections of reinforced concrete structures at a special limiting state, to ensure the protection of buildings and structures from progressive collapse.]]></description>
      <pubDate>Tue, 25 Mar 2025 09:28:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407790</guid>
    </item>
    <item>
      <title>Proposal for a New Frontal Crash Test Procedure to Meet Self Protection and Compatibility Needs</title>
      <link>https://trid.trb.org/View/1787410</link>
      <description><![CDATA[Compatibility between cars is a major issue worldwide. In Europe several groups are dealing with it: BRITE EURAM, which involves the majority of European manufacturers, and EEVC WG15, involving several European test laboratories and institutes, are the most active in Europe at the moment. In the past also ADAC developed a similar study in Germany. In US NHTSA is conducting studies, mainly related to the particular American market, where pick-ups represent the most important cause of incompatibility. Several approaches and test procedures are proposed to assess compatibility which consider tests against fixed obstacles, like offset deformable barriers and full width barrier (to measure energy absorption and stiffness of the front end and its distribution) and overload tests (to measure resistance capability of the compartment). All these kinds of tests are aimed mainly to measure structural behaviour of the cars, without taking into account the actual deceleration pulse that a car sustains in a real accident. US are considering the use of a mobile defomable barrier, which gives, as advantage, the possibility of reproducing the actual deceleration pulse of the vehicle. The problem associated with it is the complexity and the repeatability of the test, which suggests to investigate more common test configurations more deeply. Within EEVC WG15 activities one of the authors explored the compatibility between cars in frontal collision, starting from conservation equations of classical mechanics. A “compatibility equation” was suggested to describe how vehicles share energy during crash. In this paper the described approach has been further developed theoretically, in order to take into account not only the structural behaviour of the car (particularly the front end) but also (and mainly) the deceleration that occupants sustain during crash. The result is a proposal for a new crash test procedure: this involves a new fixed deformable barrier concept, which is able to reproduce the structural and biomechanical behaviour of a compatibility reference car-to-car impact by means of the same test, the self protection level for the tested car is guaranteed.]]></description>
      <pubDate>Mon, 23 Dec 2024 10:40:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787410</guid>
    </item>
    <item>
      <title>Falling weight impact acceleration-time signals analysis for road modulus detection: Theoretical and experimental investigations</title>
      <link>https://trid.trb.org/View/2447621</link>
      <description><![CDATA[Structural modulus detection is essential for construction and maintenance in road engineering. Falling weight impact loading method has significant strengths in large-scale, continuous, and rapid detection. To provide theoretical support for this, theoretical analysis and falling weight impact experiments were employed in this study to investigate the influence of road structure parameters and falling weight impact parameters on impact acceleration-time signals. First, the applicability of the Hertz model in road detection was analyzed, and theoretical formulas for peak acceleration amax and impact duration 𝑡₂ were established, considering the perfectly elastic collision between falling weight and half-space. Second, the influence of layered structures’ properties on impact acceleration-time curves was studied through model box impact experiments. Third, field tests were conducted to study engineering applications. The results showed that the influence patterns were similar in both theoretical and experimental studies, with differences reflected in the time of compression and restitution phases due to the road materials’ viscosity and plasticity. Additionally, in indoor experiments, amax showed an excellent power function relationship with structural layer modulus, with 𝑅² more than 0.95, and the contribution of each layer’s modulus to amax decreased from top to bottom. Finally, 𝑎 ₘₐₓ and resilient modulus of an old road also followed a good power function relationship, with 𝑅² around 0.76. This study revealed that 𝑎 ₘₐₓ was recommended for road surface modulus detection based on solid theoretical and experimental support.]]></description>
      <pubDate>Mon, 18 Nov 2024 17:09:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2447621</guid>
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