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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Compressive Properties and Failure Behavior of Aggregate-Segregated Asphalt Mixtures: Laboratory Testing and Digital Image Correlation Approach</title>
      <link>https://trid.trb.org/View/2591065</link>
      <description><![CDATA[To investigate the compressive properties and failure behavior of aggregate-segregated asphalt mixtures from an integrated macro-meso perspective, AC-13 and OGFC-16 asphalt mixtures with varying degrees of segregation were designed and prepared for uniaxial compression tests. Using digital image correlation (DIC) technology, the first derivative of the load-time curve of segregated asphalt mixtures and the horizontal displacement rate on both sides of the primary crack were studied. Additionally, the failure process of segregated asphalt mixtures was explored, and a parameter was proposed to evaluate the failure width of the primary crack. The results show that both compressive strength and failure displacement of AC-13 segregated asphalt mixtures initially increase and then decrease as the degree of aggregate segregation rises. For OGFC-16 segregated asphalt mixtures, the peak load continues to rise with the increasing degree of aggregate segregation, resulting in greater compressive strength and failure displacement. Following aggregate segregation, the trends in the variation of elastic energy and dissipated energy for both AC-13 and OGFC-16 asphalt mixtures are consistent with compressive strength and failure displacement. The load-time curves can be segmented into four distinct stages such as the slow growth period, growth period, attenuation period, and period corresponding to negative values, based on the first-order derivative. Coarse-aggregate segregation results in the premature formation of initial cracks, subsequent crack propagation, and eventual failure of the AC-13 mixture, making the AC-13 segregated asphalt mixture more susceptible to adhesive failure, characterized by a significant difference in horizontal displacement rates on either side of the primary crack. Conversely, fine-aggregate segregation delays the onset and development of cracks, so the OGFC-16 mixture mainly manifests as cohesive failure, evidenced by smaller differences in horizontal displacement rates on either side of the primary crack. The proposed parameter, Wv, provides an effective means to assess the deformation capacity of asphalt mixtures after initial cracks appear but before the onset of macroscopic failure.]]></description>
      <pubDate>Thu, 16 Oct 2025 17:02:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2591065</guid>
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    <item>
      <title>Effect of Segregation Tendency of Aggregates on Macroscopic Properties of Asphalt Mixture Based on Composite Geometric Characteristics</title>
      <link>https://trid.trb.org/View/2407997</link>
      <description><![CDATA[The composite geometric characteristics of coarse aggregates can effectively evaluate the combined effect of geometric morphology and size distribution in particle system. The composite angularity indices can be used to evaluate the segregation tendency of aggregates. To analyze the effect of aggregate segregation on the macroscopic properties of asphalt mixtures on the microscopic level, five segregated asphalt mixtures were designed, and the macroscopic properties were measured by a set series of tests encompassing Superpave gyratory compactor test, immersion Hamburg wheel-tracking test and indirect tensile test. The results show that the heavier the coarse aggregate segregation, the higher composite geometric indices, which are closely related to the macroscopic properties of segregated asphalt mixture. The composite angularity and textures play a greater role in the contact properties of the particle system and the macroscopic properties of the asphalt mixture than the composite shape. The large composite geometric indices imply strong contact among coarse aggregate, impeding the process of compaction. The low segregated asphalt mixture has most stable skeleton-bonding structure formed by the interaction of the geometric morphology and asphalt binder, and its resistance to rutting deformation, water stability and low-temperature crack resistance are best.]]></description>
      <pubDate>Wed, 24 Sep 2025 08:57:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407997</guid>
    </item>
    <item>
      <title>Underwater Concrete Pours and Non-Segregating Concrete</title>
      <link>https://trid.trb.org/View/2526503</link>
      <description><![CDATA[Underwater concrete placement in bridge substructures often raises concerns regarding concrete quality, primarily due to the potential for aggregate segregation, especially in deep drilled shafts. Recognizing these challenges, the goal of this research project was to critically evaluate and recommend enhancements to existing Wisconsin Department of Transportation (WisDOT) policies, standards, and specifications regarding underwater concrete placement for bridge substructures and the prevention of aggregate segregation in deep drilled shafts. Relevant research studies and the practices of other departments of transportation (DOTs) and the construction industry, especially agencies and companies operating in marine settings, were explored. Additionally, a nationwide survey was distributed to key personnel in 50 state DOTs to better understand current practices, trends, and common difficulties. This research synthesis report collates and presents a detailed assessment of concrete placement techniques, challenges in the construction of pile-encased piers, strategies to achieve non-segregating concrete in foundations, and the influence of materials and construction-related variables. Based on the insights obtained, the report sets forth refinements to available guidelines, particularly those regarding the construction of concrete piers and abutments in aquatic environments.]]></description>
      <pubDate>Tue, 25 Mar 2025 09:30:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2526503</guid>
    </item>
    <item>
      <title>Evaluation Method for Compressive Properties of Segregated Asphalt Mixtures Based on Digimat and FEM Models</title>
      <link>https://trid.trb.org/View/2464840</link>
      <description><![CDATA[To study the mechanical properties of segregated asphalt mixtures, a novel method was developed to generate three-dimensional finite element models for segregated asphalt mixtures. The virtual uniaxial compression tests under different loading rates and test temperatures were carried out to analyze the effects of aggregate segregation on the strain distribution of asphalt mixtures. Meanwhile, the uniaxial compression tests of segregated asphalt mixtures under the same test condition were carried out in the laboratory. The results show that with the increase of aggregate segregation degree, the strain value as well as the uniformity of strain distribution for AC-13 asphalt mixture decreases, and the strain value of asphalt mortar is much larger than that of aggregate particles. The strain distribution of the asphalt mixture is related to the internal structure of the asphalt mixture, and the loading rates mainly affect the magnitude of the strain value. However, the variation of test temperature not only affects the strain distribution characteristics of the asphalt mixture but also affects the magnitude of strain value. Compared with coarse aggregate segregation of high level, the influence of loading rate and test temperature on the internal strain of nonsegregated AC-13 asphalt mixture is more significant. In terms of the laboratory result, the compressive strength of dense-graded asphalt mixture first increases and then weakens with the increase in the segregation degree of coarse aggregate, while that of open-graded asphalt mixtures enhances after the segregation of fine aggregate. Furthermore, the numerical simulation based on finite element method (FEM) effectually simulates the mechanical properties of segregated asphalt mixtures, which error is less than 6.6% when compared with the results of laboratory tests. The research results can provide some references to analyze the influence of aggregate segregation on the mechanical properties of asphalt mixture without laboratory tests.]]></description>
      <pubDate>Mon, 24 Feb 2025 13:45:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2464840</guid>
    </item>
    <item>
      <title>Experimental simulation evaluation and control measures of paving segregation for the stone matrix asphalt mixtures</title>
      <link>https://trid.trb.org/View/2403566</link>
      <description><![CDATA[The aggregate segregation for asphalt mixtures, characterized by non-uniform particle distribution, significantly undermines the quality and performance of pavements. This investigation aims to explore and reveal the mechanisms underlying segregation, including raw material properties and construction procedures. Novel evaluation methods, predictive metrics, and control measures were introduced using the developed apparatus. The results indicate that physical properties, particle morphology, and gradation are fundamental factors driving segregation. Spatial hindrance, interfacial friction, collision, and self-organization collectively coordinate particle spatial migration and distribution. Excessive coarse particles induce interstitial displacement, while that of fine particles trigger third-body lubrication. The lubricating-bonding factor η was proposed to characterize asphalt regulation. Segregation prediction based on composite angularity facilitates informed raw material selection. In addition, measures to improve paving quality and efficiency during loading, unloading, and auger mixing were proposed. This research contributes to the understanding of segregation mechanisms, enabling early prevention and effective management strategies.]]></description>
      <pubDate>Fri, 09 Aug 2024 15:31:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2403566</guid>
    </item>
    <item>
      <title>A Machine Learning–Based Framework for Predicting Pavement Roughness and Aggregate Segregation during Construction</title>
      <link>https://trid.trb.org/View/2379739</link>
      <description><![CDATA[Pavement construction monitoring and quality assurance (QA) practices are based mostly on costly, discrete, and destructive methods. Most quality assurance programs are based on pavement construction procedures encompassing in situ coring for layer thickness determination, density measurements, laboratory testing to measure volumetric properties, and smoothness measurements in the case of the availability of an inertial profiler. However, most of these practices are costly and/or destructive. Therefore, the key objective of this study was to develop a quality assurance decision-making tool that can predict pavement roughness, in terms of the International Roughness Index (IRI), and aggregate segregation based on digital image analysis, image recognition, and deep machine learning models. The developed models were trained, tested, and validated using 600 pavement surface images extracted from the Louisiana Department of Transportation and Development (LaDOTD) Pavement Management System (PMS). Furthermore, the effectiveness of the convolution neural network (CNN) model was validated using pavement surface images collected at construction sites in Louisiana a few days after paving. The roughness model predicted the International Roughness Index values with a coefficient of determination R² of 0.98 and a RMS error (RMSE) of 3.5%. In addition, the developed image-processing model for the detection of aggregate segregation achieved acceptable accuracy. To support the implementation of these results, the models were incorporated into a computer application that can be used by site engineers for quality assurance without the need for coding software on their device.]]></description>
      <pubDate>Mon, 24 Jun 2024 09:26:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2379739</guid>
    </item>
    <item>
      <title>Topological Characterization and Typical Topologies of Disruption Aggregates in Asphalt Mixture</title>
      <link>https://trid.trb.org/View/2369286</link>
      <description><![CDATA[Mesoscale contact networks for asphalt mixtures play a crucial role in load resistance. However, there is a lack of quantitative characterization methods for contact networks. Topology can describe the contact relationships between multiple objects through points and lines. In this study, aggregate information was extracted by industrial computed tomography (CT) and digital image processing technology (DIP). The classification of disruption aggregates was determined by a two-dimensional (2D) topological contact model. Then, the correlation mechanism between topological indices and topologies was established based on the topological matrix. The algebraic connectivity (La) of nine different asphalt mixture disruption aggregates was analyzed. The results revealed that each type of asphalt mixture disruption aggregate was dominated by a certain La with higher frequency. As the nominal maximum size (NMAS) increased, there was a shift in the dominant topologies of different asphalt mixture disruption aggregates from those associated with lower La to those linked to higher La. Based on the higher frequency of La, there were 8 topologies with frequencies exceeding 20%; 5 with frequencies surpassing 10%; and 14 and 17 with frequencies greater than 5% and 2%, respectively. Furthermore, it was observed that the topologies of disruption aggregates predominantly consisted of simple topologies. Additionally, the frequency of complex topologies decreased as the number of nodes and connectivity increased.]]></description>
      <pubDate>Thu, 06 Jun 2024 15:31:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2369286</guid>
    </item>
    <item>
      <title>Economic strategies for low-temperature transportation of asphalt pavement: a comparative analysis of temperature variations</title>
      <link>https://trid.trb.org/View/2310432</link>
      <description><![CDATA[Highway construction strategies impact the early damage of asphalt pavement and its sustainability. The pavement quality is directly influenced by the temperature segregation of the mixture during transportation, which has rarely been investigated. Low-temperature transportation strategies for highway pavement are proposed by assessing the temperature variations in the mixture through field tests. The extreme condition of winter construction is considered, and the effects of insulation materials are considered in laboratory and field tests. A 3D Multiphysics Coupling Finite Element model is developed in COMSOL to analyse the heat transfer mechanism. The vehicle speed, thermal conductivity and ambient temperatures are considered in this parametric study. The economic efficiency of intelligent transportation is improved by optimising the effective area and the thickness of insulation materials. This study aims to propose economic strategies to avoid the temperature segregation of pavement materials and to explore more environmentally friendly insulation measures for low-temperature highway constructions.]]></description>
      <pubDate>Tue, 19 Mar 2024 15:20:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310432</guid>
    </item>
    <item>
      <title>Impact of Construction Practices on Air Voids and Permeability of Asphalt Mixtures</title>
      <link>https://trid.trb.org/View/1973854</link>
      <description><![CDATA[Several isolated premature failures on the rehabilitated portion of the Lahore-Islamabad M-2 Motorway were observed within a year of opening to traffic. Based on the visual evaluation of the distresses, failure causes could be attributed to poor in-pavement and surface drainage on the rehabilitated sections, segregation of HMA mixture, HMA mix-design, and the presence of heavy axle loads in the outer lanes. Cores in the distressed and normal areas were taken in different sections along the south and north bound directions and several destructive tests were conducted on the HMA materials to determine the field compacted air voids. Also, field permeability in-situ tests were conducted on the same locations where cores were taken. Results showed that the mix segregation occurring in the fast lanes resulted in higher field air voids than the plant mixed-lab compacted samples. Thus, the permeability of mixes in these locations was significantly higher than expected, which caused water to seep through the surface mixes in all lanes. Additionally, due to the cross-fall of the HMA and aggregate base layers, the moisture entering in the fast and middle lanes accumulated under the outer lanes in both directions.]]></description>
      <pubDate>Sat, 28 Oct 2023 16:45:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1973854</guid>
    </item>
    <item>
      <title>Investigation on mesoscopic pore characteristics in asphalt mixtures under the coupling effects of Segregation-Dynamic pore Water-Salt corrosion based on CT scanning technology</title>
      <link>https://trid.trb.org/View/2242663</link>
      <description><![CDATA[This paper explored the mesoscopic pore characteristics of asphalt mixtures by considering the coupling effects of grading segregation, dynamic pore water, and salt erosion, utilizing CT scanning technology. The study yielded the following key findings: 1) Under the coupling effects of grading segregation, dynamic pore water, and salt erosion, the sample with heavy segregation of coarse aggregate (HC) exhibited the highest variation in porosity, followed by the sample without gradation segregation (D), while the sample with heavy segregation of fine aggregate (HF) showed the least change. 2)The influence of gradation segregation on different mesoscopic pore characteristics demonstrated significant dispersion before and after the coupling effects of multiple factors. 3)From a mesoscopic scale perspective, this paper proposes a method to assess moisture sensitivity. The results obtained through this method indicate that the coordination number (CN) exhibits significantly stronger moisture sensitivity compared to other mesoscopic pore parameters.]]></description>
      <pubDate>Tue, 10 Oct 2023 11:38:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2242663</guid>
    </item>
    <item>
      <title>Mechanistic Evaluation of Segregation in HMA Mixes – Case Study</title>
      <link>https://trid.trb.org/View/2237963</link>
      <description><![CDATA[Segregation in hot mix asphalt (HMA) mixture is defined as the separation of the coarse aggregate particles in the mix from the rest of the mass. Segregation can be a result of aggregate stockpiling and handling, production, storage, truck loading practices, construction practices, and equipment adjustments. Segregation is usually evaluated visually which is considered a subjective method with no definite limits and depends on the evaluator’s opinion.This study used two mechanistic surface texture indicators, i.e., mean texture depth (MTD) which is measured using Sand Patch Method and mean profile depth (MPD) using laser texture profilometer to evaluate if a road section is segregated or not.The Sand Patch Method is standardized in ASTM E965 -15 (2019) “Standard Test Method for Measuring Pavement Macrotexture Depth Using Volumetric Technique”. MPD is covered by the international standards ASTM E1845-15 “Standard Practice for Calculating Pavement Macrotexture Mean Profile Depth”Using both measured MTD values at grid points crossings, and average MPD values at 25m intervals in the wheel paths, in addition to the use of statistical analysis of the obtained data, assuming that the obtained data are normally distributed and finding the 95% probabilities limits of the MTD and MPD values, it was possible to prove the closeness of the obtained texture depth indicators data, homogeneity of the road section and that the segregation is only present at very limited localized locations.]]></description>
      <pubDate>Tue, 03 Oct 2023 15:37:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2237963</guid>
    </item>
    <item>
      <title>Real-time identification of asphalt mixture segregation during paving process using digital imaging technique and Four-side static moment</title>
      <link>https://trid.trb.org/View/2212573</link>
      <description><![CDATA[The uniformity of the asphalt mixture is severely affected by aggregate segregation during the paving process, and there are many studies that indicate that segregation may lead to early pavement damage. This study aims to develop a real-time asphalt mixture segregation identification algorithm during paving process based on digital imaging technique and the static moment method. Static moments of the aggregate particles relative to the four boundaries of the image were calculated as an evaluation parameter, and the dispersion coefficient between the static moment of segregated asphalt mixture and the value of uniform asphalt mixture was calculated to quantify the degree of segregation. The algorithm was applied in a filed construction project in Yunnan, China. Comparing the result from the proposed algorithm with the sand patch test shows that the proposed algorithm is capable of detecting the segregation of an asphalt mixture in real-time and that it is accurate in identifying the degree of segregation. In addition, the proposed algorithm is more accurate than the sand patch test for areas where the gradation meets the standard but the distribution of the aggregate particles is not uniform.]]></description>
      <pubDate>Mon, 28 Aug 2023 09:34:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2212573</guid>
    </item>
    <item>
      <title>Analysis of mechanism and evaluation of asphalt mixtures segregation based on DEM simulation</title>
      <link>https://trid.trb.org/View/2217022</link>
      <description><![CDATA[Asphalt mixture segregation is worth paying more attention in construction. The motion of aggregates and paving quality are affected by the asphalt mortar. Therefore, the mechanism and evaluation of mixture segregation are investigated. The discrete element simulation (DEM) considering asphalt film and JKR cohesion was established. Simulation parameters based on asphalt mortar adhesion were calibrated by the surface energy density (γ), restitution, friction coefficient. The evaluation indicator of segregation (S2) was amended by gradation distribution and mass ratio of coarse aggregates. On this basis, mutual effects of segregation degree, 30 groups gradation and γ (0.0135 J/m2, 0.0155 J/m2, 0.0175 J/m2 and 0.0255 J/m2) were revealed through slump simulation. Results show that the asphalt mortar thickness of AC20 was 0.834 mm, with median gradation. Then, DEM coefficients were calibrated as 0.155 J/m2, 0.13, 0.58 and 0.3, respectively. From the different mass ratio of coarse aggregates, 19–26.5 mm, 16–19 mm and 2.36–4.75 mm contributed to homogeneity crucially. Moreover, the trend of S2and γ is opposite. It means that increasing the viscosity and dosage of asphalt can reduce segregation.]]></description>
      <pubDate>Mon, 28 Aug 2023 09:34:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2217022</guid>
    </item>
    <item>
      <title>Segregation evaluation of concrete pavements under excessive vibration using electrical resistivity measurement</title>
      <link>https://trid.trb.org/View/2211381</link>
      <description><![CDATA[Concrete pavements are typically constructed using slipform pavers. A vibration process is required to consolidate low workability concrete. However, improper vibration of fresh concrete can cause concrete pavement degradation, such as aggregate segregation and bleeding. This study evaluates the segregation of fresh concrete pavements under excessive vibration by measuring the electrical resistivity using the surface-contact electrode method. Various concrete mix proportions prepared with the recommended low slump values (25-75mm) were consolidated using conventional and excessive vibrations controlled using a poker vibrator to cause the segregation including ingredient separation. The degree of segregation through the continuous vibration process was evaluated using the measured electrical resistivity and its decreased ratio. In addition, the occurrence of segregation was compared with the ratio of coarse aggregate settlement using the wet-sieving test. Under excessive vibration, the electrical resistivity of concrete having low slump values was decreased due to the rising of water without the settlement of coarse aggregate, but the concrete mixture having the highest workability shows that the coarse aggregate was settled about 160% under excessive vibration with the decreased electrical resistivity about 15%.]]></description>
      <pubDate>Wed, 26 Jul 2023 15:59:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2211381</guid>
    </item>
    <item>
      <title>Assessing and Using the Segregation Potential in Pavement Engineering</title>
      <link>https://trid.trb.org/View/2160555</link>
      <description><![CDATA[During winter, frost penetrates in pavement materials and subgrade soils. When the frost front reaches frost susceptible subgrade soils, water is sucked toward the frozen fringe where ice lenses are formed. Heave of the pavement surface resulting from these phenomena can reach and even exceed 150 mm for climatic conditions prevailing in Canada. Frost heave in soils is the result of the combined action of heat and moisture transfer in freezing soils. Freezing soils in a pavement system are subjected to a thermal gradient. As a result, a negative pore water pressure gradient is created behind the freezing front, in a thin layer of partly-frozen soil known as the frozen fringe. Based on this understanding of the frozen fringe conditions, Konrad and Morgernstern (1980) have developed the segregation potential concept to model one dimensional frost heave in soils. The segregation potential is a mechanistic index allowing for the quantification of the frost susceptibility of a given soil in specific climatic conditions. The segregation potential concept has been used for more than two decades for several engineering applications. The paper will describe how the segregation potential can be assessed using a freezing test or estimated using various approaches. It will also describe how the segregation potential can be used to perform frost analysis of pavements subjected to cold climates.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2160555</guid>
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