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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>Bulk modulus prediction of concrete with graded transition zone</title>
      <link>https://trid.trb.org/View/2528464</link>
      <description><![CDATA[The bulk modulus of concrete is modeled by assuming that the spherical aggregate surrounded by an interfacial transition zone whose elastic moduli vary as a power law function of radius. Based on the sphere assemblage model and differential approach, the ordinary differential equation for bulk modulus is derived. The macroscopic bulk modulus of concrete materials are predicted by numerical integration. The effect of transition zone is also investigated.]]></description>
      <pubDate>Wed, 23 Apr 2025 16:15:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528464</guid>
    </item>
    <item>
      <title>Attenuation Characteristics of Plane Waves by Metabarriers with Negative Parameters</title>
      <link>https://trid.trb.org/View/2113266</link>
      <description><![CDATA[Metamaterials have come to the fore in the fields of electromagnetics and acoustics due to their superior performance in targeted frequency ranges. However, the related application such as in vibration mitigation in civil engineering is rare. In this paper, the dispersion relation of a new kind of metabarriers is obtained according to the theory of periodic structure in solid mechanics. The dispersion of the metabarriers is generated by local resonance. A simplified model is established to explain the mechanism of bandgaps. The effective mass density, effective shear modulus and effective bulk modulus of the metabarriers are calculated by finite element method. It is found that the resonance of the oscillator produces a negative effective mass density, which prevents the wave propagating in soil, thus creating bandgaps. At this point, the effective shear modulus and effective bulk modulus of the metabarriers are both positive. The findings of this paper are beneficial for the design of periodic pile barriers to isolate elastic waves propagating in soil.]]></description>
      <pubDate>Mon, 10 Apr 2023 11:58:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113266</guid>
    </item>
    <item>
      <title>Analysis and experiment of HMT stationary shift control considering the effect of oil bulk modulus</title>
      <link>https://trid.trb.org/View/1847786</link>
      <description><![CDATA[In order to improve the shift quality of hydro-mechanical continuously variable transmission, the effect of tangent bulk modulus and different control methods on the shift quality were analyzed. Theoretical analysis and experimental study on the tangent bulk modulus of oil were carried out to obtain the effect law of air content on the tangent bulk modulus of oil. A four-cavity model of a closed hydraulic circuit was established based on a two-stage arithmetic type hydro-mechanical transmission. By means of simulation analysis and experimental study, the effect of the tangent bulk modulus of oil on the shift quality is studied. The lean control method of reasonably controlling displacement ratio and prolonging the reverse time of load torque is put forward. The results show that this method can reduce the fluctuations of the speed of the fixed displacement motor and the oil pressure of the original low-pressure side. This method can also improve the shift quality and provide reference for the study of the shift process of hydro-mechanical continuously variable transmission.]]></description>
      <pubDate>Wed, 28 Apr 2021 09:28:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847786</guid>
    </item>
    <item>
      <title>Modulus Simulation of Asphalt Binder Models Using Molecular Dynamics (MD) Method</title>
      <link>https://trid.trb.org/View/1501840</link>
      <description><![CDATA[The objectives of this study are, 1) to simulate asphalt binder modified with exfoliated multi-layered graphite nanoplatelets (xGNP) using the Molecular Dynamics (MD) method, and 2) to analyze different modulus properties of these asphalt binder models compared with those of the control asphalt binder model. The multi-layered graphene model was used to represent the xGNP particles, which were used to modify the control asphalt in the laboratory. The three-component control asphalt binder model was used as in the authors’ previous study. The xGNP modified asphalt binder model was built by incorporating the xGNP model and control asphalt binder model and controlling mass ratios to represent the laboratory prepared samples. After the xGNP modified asphalt binder model was generated, the densities of the control and xGNP modified asphalt binder models were computed and verified. Mechanical properties of these models were simulated and calculated in MD simulations using procedures similar to those in the experiments, which include the bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio. The simulation results indicate that the temperature-modulus trends of these asphalt binder models were comparable to those of the laboratory data. The MD simulation data were larger than the laboratory results due to limitations of the current MD simulation, which are discussed in this study. In addition, Poisson’s ratios calculated from the MD simulations coincided with the laboratory results.]]></description>
      <pubDate>Fri, 30 Mar 2018 09:54:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501840</guid>
    </item>
    <item>
      <title>Effects of Entrapped Gas within the Fluid on the Stiffness and Damping Characteristics of a Hydro-Pneumatic Suspension Strut</title>
      <link>https://trid.trb.org/View/1461320</link>
      <description><![CDATA[This study is aimed at characterizing the nonlinear stiffness and damping properties of a simple and low cost design of a hydro-pneumatic suspension (HPS) that permits entrapment of gas into the hydraulic fluid. The mixing of gas into the oil yields highly complex variations in the bulk modulus, density and viscosity of the hydraulic fluid, and the effective gas pressure, which are generally neglected. The pseudo-static and dynamic properties of the HPS strut were investigated experimentally and analytically. Laboratory tests were conducted to measure responses in terms of total force and fluid pressures within each chamber under harmonic excitations and nearly steady temperature. The measured data revealed gradual entrapment of gas in the hydraulic fluid until the mean pressure saturated at about 84% of the initial pressure, suggesting considerably reduced effective bulk modulus and density of the hydraulic fluid. An analytical model of the HPS strut was formulated considering polytropic change in the gas state and increased fluid compressibility due to entrapped air. Both the measured data and the model results showed progressively hardening stiffness of gas during compression, while the damping effect attributed to fluid flows between different chambers was higher during strut rebound. The results further suggested that 20% decrease in fluid density and effective bulk modulus will result in about 18% decrease in the equivalent damping coefficient and 2% decrease in the equivalent stiffness. The reduction in mean strut pressure would also yield relatively higher static deflection of the HPS strut, which could necessitate an additional height adjustment mechanism.       ]]></description>
      <pubDate>Tue, 16 May 2017 09:30:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1461320</guid>
    </item>
    <item>
      <title>Application of CEL Method for Simulation of Multiphysics Events in Automobiles</title>
      <link>https://trid.trb.org/View/1431724</link>
      <description><![CDATA[In automobiles, there are various multiphysics (specifically fluid structure interaction) events taking place which are very important from vehicle operations. Examples are - oil splashing in engine, water spraying on the windscreen, fuel sloshing in a tank etc. The simulation of such events becomes important in the design stage in order to study their proper functioning before the prototypes are made.         This paper enlightens the systematic procedures developed for the simulation of such events using coupled Euler-Lagrangian method available in commercial finite element explicit codes.         These simulations are very time consuming because of very small time steps and very large cycle time. To overcome this problem an attempt is made to use rigid bodies and a low bulk modulus fluid to speed up the simulation exponentially. These quick simulations can be used for early design iterations and final designs can be revalidated with flexible bodies and correct bulk modulus.         Based on this simulation method, following case studies are presented.        ]]></description>
      <pubDate>Fri, 28 Apr 2017 10:40:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1431724</guid>
    </item>
    <item>
      <title>Study of Moisture Impact on Asphalt Before and After Oxidation Using Molecular Dynamics Simulations</title>
      <link>https://trid.trb.org/View/1394181</link>
      <description><![CDATA[Moisture effects on asphalt before and after oxidative aging are investigated in this paper with the molecular dynamics (MD) simulation method. Density, bulk modulus, and zero shear viscosity changes of unoxidized and oxidized asphalt under different moisture contents are compared. The simulations were conducted at 25°C with 0% and 1%, to 10% moisture inclusion incremented by 2.5%. Simulation results showed that the density, bulk modulus, and zero shear viscosity of oxidized asphalt were higher than those of the unoxidized asphalt before any moisture inclusion. These results indicate that hardening happens in asphalt during oxidation. However, after moisture inclusion, the bulk modulus and the zero shear viscosity of unoxidized and oxidized asphalt decreased with an increase in moisture content. Laboratory validation of zero shear viscosity for the unoxidized asphalt showed a result consistent with MD simulation. The moisture effect on density change was not significant for unoxidized or oxidized asphalt, but the density fluctuations of oxidized asphalt were higher than for the unoxidized asphalt. Moreover, moisture affects the bulk modulus and zero shear viscosity of oxidized asphalt more negatively, compared with the unoxidized asphalt. Specifically, the bulk modulus and zero shear viscosity of oxidized asphalt decreased faster than the unoxidized asphalt with moisture inclusion and became lower than the unoxidized asphalt after 5% moisture inclusion. This result indicates that oxidized asphalt is more susceptible to moisture damage.]]></description>
      <pubDate>Tue, 29 Mar 2016 09:35:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1394181</guid>
    </item>
    <item>
      <title>Investigation of Oxidation Effect on the Properties of Asphalt Under Different Temperatures Using Molecular Simulation and Laboratory Testing</title>
      <link>https://trid.trb.org/View/1394106</link>
      <description><![CDATA[The physical and rheological property changes of asphalt before and after oxidative aging under wo different temperatures, 25 °C and 58 °C, are studied using Molecular dynamics (MD) simulation method, regarding density, bulk modulus and zero shear viscosity (ZSV). Superpave performance grading (PG) non-modified binder, PG 58-22 before and after aging has been used for laboratory validations of simulation results, which has been aged through Rolling Thin-Film Oven (RTFO) and Pressure Aging Vessel (PAV) to represent short-term and long-term aging, respectively. The density results prove that the unoxidized and oxidized asphalt models developed for MD simulation are credible to represent real asphalt, which possesses similar densities as the unaged and aged PG binders, respectively. All the simulation results are consistent with laboratory testing results. Overall, density, bulk modulus and ZSV of asphalt increase with an increase in the degree of oxidation and decrease with an increase in temperature. Higher bulk modulus and ZSV in higher oxidized asphalt indicates the hardening of asphalt due to oxidation. Moreover, ZSV decreases more substantially for the oxidized asphalts at higher temperature. The viscosity difference between the two considered temperatures increased with an increase in the degree of oxidation. This indicates that the oxidized asphalt is more sensitive to temperature than the unoxidized/unaged asphalt regarding ZSV change.]]></description>
      <pubDate>Tue, 29 Mar 2016 09:35:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1394106</guid>
    </item>
    <item>
      <title>Predicting Damage in Concrete Due to Expansive Aggregates: Modeling to Enable Sustainable Material Design</title>
      <link>https://trid.trb.org/View/1144030</link>
      <description><![CDATA[A poroelastic model is developed that can predict stress and strain distributions and, thus, ostensibly damage likelihood in concrete under freezing conditions caused by aggregates with undesirable combinations of geometry and constitutive properties. Sensitivity of the stress distributions to the aggregate and matrix constitutive parameters are assessed to allow improved concrete design. The proposed model does not account for the viscoelastic stress relaxation and may over-predict the stress results. The model is evaluated experimentally through acoustic emission analysis under freeze-thaw cyclic loading, which reveals that air-entrained concrete may undergo durability cracking (D-cracking) if deleterious materials are present. It is determined that high-porosity, low-permeability aggregates with fine pore structure are the most vulnerable to D-cracking in non-air-entrained concrete, and the destructive tensile stress is generated at the aggregate boundary by the Mandel-Cryer effect. On the other hand, low-porosity, high-permeability aggregates relax the pore liquid pressure rapidly and prove to be beneficial for the non-air-entrained concrete. Reduction in aggregate size is found to be effective in quickly relaxing the tensile tangential stress, which eventually helps mitigate D-cracking of concrete. The difference between the coefficients of thermal expansion of the coarse aggregate and the matrix in which they are embedded should not be too high since it may cause tensile stress at the aggregate boundary or interfacial transition zone. Low water-to-cement mass ratio and addition of pozzolans help increase the bulk modulus, reduce the porosity of the porous body, and improve durability. It is also observed that increase in cooling rate decreases concrete durability under freezing temperatures through the reduction in time available to relax pore pressure buildup and the related tangential stresses in the aggregate and matrix.]]></description>
      <pubDate>Tue, 24 Jul 2012 08:20:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1144030</guid>
    </item>
    <item>
      <title>Void Bulk Modulus Reduction of Porous Asphalt Mixture Based on Porous Linear Elastic Continuum Theory</title>
      <link>https://trid.trb.org/View/1110355</link>
      <description><![CDATA[The void bulk modulus reduction of porous asphalt mixtures was evaluated using the Gassmann's equation to describe the relationship between the various bulk moduli and the percentage of air voids in porous asphalt mixtures along with the theory of linear elastic material with voids. A continuum interpretation of the porosity of the material was presented and used in the paper. The void bulk modulus was considered to represent the air voids reduction of the porous asphalt mixtures. The data showed a larger reduction in the void bulk modulus for the dry state when compared to the saturation state. The void bulk modulus under the dry state decreased by 8.4% with the 25% reduction in the initial air voids. However, the void bulk modulus decreased by 7.8% under the saturation state.]]></description>
      <pubDate>Mon, 08 Aug 2011 14:26:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1110355</guid>
    </item>
    <item>
      <title>Does the Al substitution in C-S-H(I) change its mechanical property?</title>
      <link>https://trid.trb.org/View/1084386</link>
      <description><![CDATA[This study examines the influence of Al substitution for Si on the bulk modulus of calcium silicate hydrate I [C-S-H(I)], a structural analogue of C-S-H, by performing high-pressure synchrotron X-ray diffraction experiments in two C-S-H(I) samples: one a hydration product of alkali-activated slag and the other a synthetic C-S-H(I). The test result shows that not only the bulk modulus but also the incompressibility of the lattice parameters a, b, and c of two C-S-H(I) samples are very similar to each other, regardless of the Al substitution. This result may be due to the four-coordinated configuration of the substituted Al, which makes the dreierketten silicate chains maintain the same arrangement after the substitution.]]></description>
      <pubDate>Wed, 19 Jan 2011 10:52:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1084386</guid>
    </item>
    <item>
      <title>Bulk modulus of basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, a possible zeolitic precursor in coal-fly-ash-based geopolymers</title>
      <link>https://trid.trb.org/View/1084389</link>
      <description><![CDATA[Synthetic basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, cubic, P43n, (also known as hydroxysodalite hydrate) was prepared by the alkaline activation of amorphous aluminosilicate glass, obtained from the phase separation of Class F fly ash. The sample was subjected to a process similar to geopolymerization, using high concentrations of a NaOH solution at 90°C for 24 hours. Basic sodalite was chosen as a representative analogue of the zeolite precursor existing in Na-based Class F fly ash geopolymers. To determine its bulk modulus, high-pressure synchrotron X-ray powder diffraction was applied using a diamond anvil cell (DAC) up to a pressure of 4.5 GPa. A curve-fit with a truncated third-order Birch-Murnaghan equation of state with a fixed K'o = 4 to pressure-normalized volume data yielded the isothermal bulk modulus, Ko = 43 ± 4 GPa, indicating that basic sodalite is more compressible than sodalite, possibly due to a difference in interactions between the framework host and the guest molecules.]]></description>
      <pubDate>Wed, 19 Jan 2011 10:52:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1084389</guid>
    </item>
    <item>
      <title>Analyzing Properties of Model Asphalts Using Molecular Simulation</title>
      <link>https://trid.trb.org/View/802422</link>
      <description><![CDATA[Molecular simulations have been used to estimate the properties of three-component mixtures whose constituents were chosen to represent the chemical families found in paving asphalts. Naphthene aromatics and saturates were represented by 1,7-dimethylnaphthalene and n-C22, respectively. Two different asphaltene model structures were considered. The first has a large aromatic core with a few short side chains; the second contains a moderate size aromatic core with larger branches. Both types have been proposed in the recent literature based on experimental characterizations of asphaltene fractions. Properties calculated from atomistic molecular simulations of the mixtures include density, isothermal compressibility (inverse of bulk modulus), and zero shear viscosity. The thermodynamic properties suggest a high frequency glass transition above 25ºC for both model mixtures. The mixture based on the more aromatic asphaltene shows a more pronounced transition and has a higher bulk modulus. The calculated viscosity at elevated temperatures is somewhat smaller than that of real asphalts. For a polymer-modified model asphalt, the calculations are consistent with increases in viscosity and bulk modulus.]]></description>
      <pubDate>Wed, 21 Mar 2007 12:46:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/802422</guid>
    </item>
    <item>
      <title>Wave-Induced Pore Pressures—Air/Gas Content</title>
      <link>https://trid.trb.org/View/796174</link>
      <description><![CDATA[Wave induced pore pressures in bottom soils have an influence on the geotechnical stability of structures and may also have an effect on the transport of sand. Wave induced pore pressures in a seabed of sand or clay has been an item for extensive research. One of the major difficulties in analyzing and interpreting both laboratory and field data has been related to the question of air/gas content in the pores of fine soil. Only a small fraction of air/gas significantly changes the bulk modulus of the water/gas mixture and also the attenuation of the wave induced pressures in the soil with depth. The reason for the difficulty of analyzing data has been the lack of good instrumentation for measuring the gas content in the seabed soil.]]></description>
      <pubDate>Tue, 30 Jan 2007 13:27:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/796174</guid>
    </item>
    <item>
      <title>Highway Concrete Pavement Technology Development and Testing: Volume III—Field Evaluation of Strategic Highway Research Program (SHRP) C-205 Test Sites (High-Performance Concrete)</title>
      <link>https://trid.trb.org/View/790409</link>
      <description><![CDATA[This research study, sponsored by the Federal Highway Administration, summarizes the field performance of eight high-early-strength (HES) concrete patches between 1994 and 1998. The patches were constructed under the Strategic Highway Research Program (SHRP) between June 1991 and July 1992 and were located in five States (Arkansas, Illinois, Nebraska, New York, and North Carolina) using existing State construction practices. The patches were constructed mainly with Type III cement, four different types of coarse aggregate, and three different types of fine aggregate. Similar types of air entraining admixtures, water reducers, and set accelerators were used at all except the North Carolina site. The patches were located in areas with varying environmental and traffic conditions. The performance criterion of interest was durability. Durability of the HES concrete was quantified over a period of 7 years using various indicators including compressive strength, static elastic modulus, rapid chloride permeability, and asphalt concrete (AC) impedance. The HES patches were also examined visually to locate any material- or durability-related distresses. This report discusses in detail the effects of climate and material properties on the HES concrete durability.  Some of the results of interest include the effect of water reducer type, curing method, and aggregate type on long-term durability. The report also presents comparisons of the rapid chloride permeability and AC impedance test results and the rate of strength gain for the mixes evaluated. Overall, the HES patches performed well with no obvious signs of deterioration. However, the results were not conclusive because the performance-monitoring period was relatively short. There is a need for further research in the areas of long-term HES concrete mechanical properties and durability.]]></description>
      <pubDate>Fri, 06 Oct 2006 11:26:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/790409</guid>
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