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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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Influence of Specimen Geometries on the Viscoelastic Properties of Bituminous Mixtures in Torsion</title>
      <link>https://trid.trb.org/View/2350651</link>
      <description><![CDATA[A standard test method for determining the linear viscoelastic properties of bituminous mixtures in torsion prescribes the use of a dynamic shear rheometer. The method uses a prismoidal specimen (rectangular cross section) sliced from a Superpave gyratory compacted sample. However, the geometry utilized in the standard is a non-axisymmetric cross section, which leads to the development of warping stress when the specimen is tested in torsion using a dynamic shear rheometer. On the other hand, axisymmetric geometry, such as cylinder (circular cross section), does not warp when subjected to torsion. This study investigates the influence of the two specimen geometries, namely prismoidal and cylindrical, on the linear viscoelastic properties of bituminous mixtures in torsion. The specimens are obtained from a bituminous mixture with a nominal maximum aggregate size of 13.2?mm, and statistical analysis is carried out to determine whether the material constitution in the specimen geometries is identical. A frequency sweep experiment is conducted at 10, 20, and 30°C with a constant strain amplitude of 0.001% in the frequency range of 0.01?Hz to 20?Hz. The absolute shear modulus of the prismoidal specimens is found to be higher than that of cylindrical specimens because of warping stresses in prismoidal specimens. It was seen that the effect of warping stress is greater at higher temperatures and lower frequencies. Correction factors are used to correct the absolute shear modulus of prismoidal specimens. These findings highlight the importance of considering correction factors for warping when characterizing prismoidal bituminous mixtures in torsion.]]></description>
      <pubDate>Tue, 12 Mar 2024 11:04:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2350651</guid>
    </item>
    <item>
      <title>A Retroreflective Road Lane Marking Tape 1,000X Brighter than Existing Technology</title>
      <link>https://trid.trb.org/View/1942300</link>
      <description><![CDATA[This Innovations Deserving Exploratory Analysis (IDEA) program project developed an ultra-bright traffic stripe made from a thin transparent polymer film with prismatic patterns formed on both the top and bottom surfaces of the polymer film. The new traffic stripe uses neither paint nor glass beads to provide unprecedented retroreflectivity on dark highways at night. The top surface includes light-turning prisms facing in both directions of traffic. Rays from distant headlights are totally internally reflected (TIR) by a sloped surface downward onto cube corner prisms covering the bottom surface of the polymer film. The cube corner prisms retroreflect the rays in the opposite direction so these rays eventually return to the driver (and the sensors) of the vehicle. The cube corner prism technology has been successfully used for decades in traffic signs which are very bright and durable. The present innovation enables this previously developed cube corner sign technology to be applied to traffic stripes to make the new stripes as bright as road signs.]]></description>
      <pubDate>Tue, 19 Apr 2022 13:06:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1942300</guid>
    </item>
    <item>
      <title>Functional Characteristics of Ultra-High-Performance Concrete Comprising Various Fibers</title>
      <link>https://trid.trb.org/View/1753603</link>
      <description><![CDATA[This paper presents the characteristics of a cost-effective ultra-high-performance concrete (UHPC) made of locally available constituents. The implications of steel and synthetic fibers on the shrinkage, maturity, and chloride permeability of the silica-based concrete are of interest. To implement assorted standard test methods, UHPC cylinders and prisms are cast and instrumented. The interaction between the fibers and cement paste affects the shrinkage of UHPC. Owing to the absence of coarse aggregate, the applicability of existing shrinkage models for ordinary concrete is not satisfactory; accordingly, a new expression is proposed. The early-age hydration of cement (less than 1 day) generates thermal energy, depending upon fiber type, which raises the temperature of the concrete. The load-carrying capacity of UHPC mixed with steel fibers is higher than that of UHPC with synthetic fibers. The maturity of UHPC is contingent upon fiber configuration; specifically, plain and steel-fiber-mixed UHPC cylinders show a superior early-age strength gain to those with synthetic fibers. For the Nurse-Saul and the Arrhenius maturity approaches (time temperature factor and equivalent age, respectively), regression equations are fitted. The flow of electric current and the resistivity of UHPC are favorable due to the densely formulated grain structure, leading to the improvement of durability when used for structural application. The diffusion coefficient of UHPC increases as the mixed fibers create interfacial gaps in the cement paste.]]></description>
      <pubDate>Tue, 22 Dec 2020 09:36:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1753603</guid>
    </item>
    <item>
      <title>Optical design of light guide prisms with surface roughness for automotive tail lights</title>
      <link>https://trid.trb.org/View/1718320</link>
      <description><![CDATA[This study presents the optical design of light guide prisms for automotive tail light applications to obtain the optimum luminous intensity and the illuminance uniformity. The design was achieved using optical design software, SPEOS. By considering the axial luminous intensity and legal requirements, the optimum prism angles of light guides were determined by simulations. After determining the prism angles, the effect of different surface roughness on the luminous intensity and the illuminance uniformity was investigated. The light guides designed by considering data from the simulation were manufactured as prototypes and their photometrical measurements were made. These measurements were compared to the simulation results. It was observed that simulation and prototype results are well in agreement with each other. Furthermore, it was found that as the surface roughness increases both the luminous intensity decreases and the illumination becomes more uniform.]]></description>
      <pubDate>Wed, 22 Jul 2020 14:40:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1718320</guid>
    </item>
    <item>
      <title>Development and implementation of retro-reflective elements for automatic accessories and places of planned points</title>
      <link>https://trid.trb.org/View/1690385</link>
      <description><![CDATA[For the first time, it was proposed to develop an optimal design of a circular reflector, to modernize the equipment for the production of a special cutting tool, and to work out the technology of formation with its use of the matrixes of the originals of the retro-reflective elements, and the technology of galvanic cultivation of precision working matrix dies.]]></description>
      <pubDate>Thu, 23 Apr 2020 15:58:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1690385</guid>
    </item>
    <item>
      <title>Reliability of Miniature Concrete Prism Test in Assessing Alkali-Silica Reactivity of Moderately Reactive Aggregates</title>
      <link>https://trid.trb.org/View/1694845</link>
      <description><![CDATA[Alkali-silica reaction (ASR) is one of the most significant durability issues in concrete structures. Although there are a number of standardized test procedures to evaluate the aggregate reactivity, each method has its own drawbacks. Two of the most common tests that are employed widely are the accelerated mortar bar test (AMBT) (ASTM C1260) and the concrete prism test (CPT) (ASTM C1293). The major issue with the AMBT test is the number of false-positive results from this test associated with high test temperature, rendering the test method unreliable. CPT is one of the most reliable tests for assessing the potential for ASR, but its major disadvantage is the duration of the test involved, which takes one to two years. In this research, a novel test method called the miniature concrete prism test (MCPT) was developed and the effectiveness and reliability of the results assessed when compared with CPT and AMBT. Samples of 26 coarse aggregates and 16 fine aggregates with various reactivity levels were employed for the testing. The test results were compared for MCPT versus CPT, in which 23 out of 26 coarse aggregates and eight out of 16 fine aggregates either passed or failed in both MCPT and CPT. For MCPT versus AMBT, 16 out of 26 coarse aggregates and 13 out of 16 fine aggregates either passed or failed in both MCPT and AMBT. The sensitivity of false-negative and false-positive aggregate sources is discussed and explained briefly.]]></description>
      <pubDate>Mon, 13 Apr 2020 10:54:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1694845</guid>
    </item>
    <item>
      <title>Creep and Shrinkage of Eccentrically Loaded Prisms</title>
      <link>https://trid.trb.org/View/1690994</link>
      <description><![CDATA[The creep behavior of eccentrically loaded prisms is reported in this study. Accurate determination of the strain gradient was found to be a very important factor in studying the time-dependent behavior of eccentrically loaded prisms. Using eccentric loading it was possible to predict the shrinkage of the prisms without the need for companion specimens. Relationships were developed to evaluate the specific creep. An exponential method was used to estimate the initial and ultimate strain gradient. The ultimate specific creep, ultimate creep coefficient and ultimate shrinkage were computed. Principles of statistics were applied to establish 80, 90 and 95 percent confidence limits for these quantities. The specific creep of all the prisms was analyzed and the 80 and 90 percent confidence limits established . The specific creep of the eccentrically loaded prisms was compared to the specific creep of the uniformly loaded prisms. No significant difference in the results was observed for the two test procedures. The shrinkage of the eccentrically loaded specimens was compared to the shrinkage of the companion unloaded specimens. Good agreement was found between the two shrinkage values obtained by these different methods of test. Recommendations are made for improving the eccentrically loaded prism test procedure and for further research needs.]]></description>
      <pubDate>Tue, 24 Mar 2020 15:18:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1690994</guid>
    </item>
    <item>
      <title>Numerical Study of Splitting/Bursting Performance of Prestressed Concrete Prisms using High Strength Concrete with Reduced Modulus of Elasticity</title>
      <link>https://trid.trb.org/View/1573337</link>
      <description><![CDATA[This study focuses on numerically evaluating the splitting/bursting performance of prestressed concrete prisms using a high strength, reduced modulus concrete recently developed at the University of South Carolina. Prestressed concrete crossties are an essential structural component of a track structure. However, premature failures of concrete crossties are of great concern in the industry. Since some of the failures are associated with the concrete being too rigid, the high strength, reduced modulus concrete was developed with the goal of mitigating some of these failures. In this study, the splitting/bursting performance of prestressed concrete prisms using the newly developed concrete is evaluated. In order to simulate the bond-slip behavior of the prestressing wires embedded in the reduced modulus concrete, a recently developed elastoplastic bond-slip model is used. Parameters required to define the bond-slip models are calibrated. In this parametric study, the minimum cover concrete and spacing between prestressing wires are recommended depending on reinforcement types and releasing strengths.]]></description>
      <pubDate>Fri, 01 Mar 2019 15:51:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1573337</guid>
    </item>
    <item>
      <title>Estimation of the Coefficient of Lateral Stress used in the Calculation of Loads on Buried Structures</title>
      <link>https://trid.trb.org/View/1557040</link>
      <description><![CDATA[The average vertical pressure on a buried structure can be calculated using the silo theory, which assumes the translation of a vertical prism of soil above the structure that is resisted by friction on the sides of the prism. One of the key assumptions made is the value of the coefficient of lateral stress, K. In this study, an assumption regarding the rotation of principal stresses in the yielding soil has been used to calculate the average coefficient of lateral stress acting at the side of a prism of yielding soil above the horizontal buried structure. The calculated value using the proposed method agrees well with experimental observation made in literature for the value of K, and is suggested for use in the estimation of loads on buried structures, where it is expected that the structure will yield relative to a stiff body of soil.]]></description>
      <pubDate>Mon, 26 Nov 2018 16:55:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1557040</guid>
    </item>
    <item>
      <title>Swirling Effects and Occurrence in Chamfered Prismatic Tanks with Partially Loaded Condition</title>
      <link>https://trid.trb.org/View/1503917</link>
      <description><![CDATA[An experiment was carried out to measure sloshing pressures and forces in a prismatic chamfered tank. The tank was excited laterally for regular and irregular excitation and the results were compared with numerical computations based on a Finite difference method. The tank has a Length to breadth ratio near 1, and especially in intermediate filling levels, at around the tank’s 1st mode sloshing frequency, the occurrence of a rotational flow, i.e. swirling, was observed. Based on the results from both model experiment and numerical simulations, there are cases where swirling loads can be significant and therefore cannot be neglected. After checking the tank dimensions of real LNG carriers, it was noted that many actual designs have tank with the length to breadth ratio near 1 and therefore the problem can be relevant. The rotational flow characteristics and its occurrence is investigated and its pressure distribution is compared with the 1st mode sloshing, finally, considerations about the tank safety are inferred concerning the swirling problem.]]></description>
      <pubDate>Fri, 27 Apr 2018 12:21:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1503917</guid>
    </item>
    <item>
      <title>Splitting/Bursting Performance of Prestressed Concrete Prisms</title>
      <link>https://trid.trb.org/View/1494469</link>
      <description><![CDATA[This numerical parametic study focuses on evaluating the splitting/bursting performance of prestressed concrete prisms. Under the sponsorship of Federal Railroad Administration, Kansas State University (KSU) experimentally characterized the bond-slip behavior of various prestressing wires and strands commonly used in railroad concrete ties in the U.S. Based on the experimentally obtained bond-slip behaviors, Volpe Center has developed elastoplastic bond-slip models as a user-defined material (UMAT). In the bond-slip models, the required parameters were calibrated with the KSU untensioned pullout and pretensioned concrete prism testing results. In this study, effects of important geometric/mechanical parameters on the splitting/bursting performance of pretensioned concrete prisms are examined by incorporating a recently developed, unified bond model into the finite element (FE) analyses of pretensioned concrete prisms. The commercial FE software ABAQUS with the unified bond-slip UMAT is used. The important geometric/mechanical parameters considered herein are: reinforcement type, initial pretension force, concrete edge cover, reinforcement center-to-center spacing and concrete mechanical properties. The results show that releasing the prestressing wires at a concrete compressive strength of 3500 psi could cause significant splitting/bursting damages in the concrete prisms and a 0.5 in. concrete cover should be avoided due to the potential of premature splitting cracks. Finally, recommendations on developing qualification tests using pretensioned concrete prism results to prevent the splitting/bursting failure of concrete ties are made.]]></description>
      <pubDate>Wed, 21 Mar 2018 10:03:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1494469</guid>
    </item>
    <item>
      <title>Green accessibility: Estimating the environmental costs of network-time prisms for sustainable transportation planning</title>
      <link>https://trid.trb.org/View/1485896</link>
      <description><![CDATA[Accessibility, or the ease to participate in activities and obtain resources in a given environment, is crucial for evaluating transportation systems. Greater accessibility is often achieved by increasing individuals' potential mobility. However, potential mobility, if realized by motorized modes, can also generate negative environmental impacts such as fossil fuel consumption and greenhouse gas (GHG) emissions. While the negative environmental impacts of greater mobility are acknowledged, there has been a lack of research to validate those impacts using empirical data, especially considering variations in individuals' mobility levels. This paper presents a method for estimating the expected environmental costs of accessibility represented by a network-time prism (NTP). A NTP delimits all accessible locations within a network and the available time for an individual to present at each location given a scheduled trip origin and destination, a time budget and the maximum achievable speeds along network edges. Estimating the expected environmental costs of a NTP involves three steps: (1) semi-Markov techniques to simulate the probabilities to move along network edges at given times; (2) the speed profiles for reachable edges, and (3) a cost function that translates speeds into environmental impacts. The authors focus on air quality and employ the motor vehicle emission simulator MOVESLite to estimate the CO2 emissions at both the edge and prism levels. They calibrate and validate the methods for experimental NTPs defined within the Phoenix, AZ, USA road and highway network using vehicles instrumented with GPS-enabled onboard diagnostic devices (OBD). They demonstrate the effectiveness of their method through two scenarios and investigate the impact of changes in mobility levels on the expected CO2 emissions associated with the experimental NTPs.]]></description>
      <pubDate>Mon, 30 Oct 2017 09:11:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1485896</guid>
    </item>
    <item>
      <title>Long-Term Effects of Different Cementing Blends on Alkali- Carbonate Reaction</title>
      <link>https://trid.trb.org/View/1475190</link>
      <description><![CDATA[The long-term effect of supplementary cementitious materials (SCMs) on alkali-carbonate reaction was evaluated using the concrete prism test for up to 10 years. None of the SCMs showed complete mitigation effects, although some types were more effective than others in reducing the expansion. Blending 10% reactive with 90% nonreactive aggregates was effective in meeting the 0.040% expansion limit at 1 year; however, the expansion was 0.074% after 10 years at room temperature. The chemical method for evaluating aggregate was found to give false negative or underestimate the potential expansion of blends of reactive and nonreactive aggregates. The use of SCMs with blends of aggregates that marginally meet the 1-year expansion limit provides some benefits in reducing the expansion at later ages. The concrete microbar test provides good correlations with the concrete prism test containing 100% reactive aggregates with and without SCM, but underestimates the expansion of blends of aggregates.]]></description>
      <pubDate>Thu, 27 Jul 2017 10:05:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1475190</guid>
    </item>
    <item>
      <title>Strengthening of the Railway Ballast Section Shoulder with Two-Component Polymeric Binders</title>
      <link>https://trid.trb.org/View/1471730</link>
      <description><![CDATA[The paper reports on the study of variation of horizontal stability of the sleeper base of a ballast section depending on the degree of ballast strengthening with a polyurethane-based two-component RT-CS-001 binder. The studies are performed on an acting section of the railroad. The thickness of the strengthened ballast is determined as a function of the binder flow rate. After GeoComposite thus formed gained full strength, modulus of elasticity of the structure is measured. It is shown that the strengthening of ballast with the binder increases Young’s modulus by a factor of four, allowing creating the track sections of varied rigidity both in the construction process and during the current maintenance of railways. Measurements of the lateral resistance of unloaded sleepers in the static mode against the flow rate of the binder fixing the shoulder of the ballast prism are performed. Strengthening of the ballast prism shoulder increases 2.7 times the static lateral resistance to the shift of the sleeper upon application of lateral load without application of vertical load; it does not prevent the use of the machines for deep cleaning of the ballast material during repair and modernization of railway tracks. It is shown that on long railways sections, the flow rate of binder material and the thickness of the resulting GeoComposite can be monitored by the ground penetrating radar (GPR).]]></description>
      <pubDate>Wed, 19 Jul 2017 15:44:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1471730</guid>
    </item>
    <item>
      <title>Constructing Full-Day Feasible Space-Time Polyhedron Using Activity-Based Space-Time Prisms</title>
      <link>https://trid.trb.org/View/1337458</link>
      <description><![CDATA[In this paper, space-time prism from time geography is applied to the decision making scheme of the Household Activity Pattern Problem (HAPP), a full-day activity-based travel demand model. An activity-based space-time prism with no prior decisions of paths (Origin-Destination) is defined as supposed to the classical path-based space-time prism with known Origin-Destination. Then the new concept of full-day feasible space-time polyhedron is defined as an intersection of a set of activity-based space-time prisms. This approach is a generalization of the classical space-time prism since the full-day feasible polyhedron often decomposes into the classical space-time prism by peg activities, activities that delimit space and time by participating in those activities. The concept of activity-based space-time prism and the full-day feasible space-time polyhedron also expands the horizon of classical space-time prism in that it can be used to define accessibility for travelers with no peg activities. A computational algorithm is developed for the construction of activity-based space-time prism and feasible polyhedron for network-based travel environment. The algorithm generates a set of time windows for each activity for each node. For a full-day activity agenda, intersections of these windows are derived. Then these node-based time windows are converted to link-based time windows of accessibility. This algorithm works for a traveler that contains peg(s) of activities as well as a traveler with no peg activity for the travel day.]]></description>
      <pubDate>Thu, 12 Mar 2015 11:55:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1337458</guid>
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