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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>
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    <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>Investigation of Thermo-Mechanical Characteristics of Wax-doped Aged Asphalt Binder</title>
      <link>https://trid.trb.org/View/1572302</link>
      <description><![CDATA[This paper investigates effects of paraffin wax on molecular conformation of aged asphalt and consequently on asphalt’s thermo-mechanical properties. Although paraffin wax is one of the prevalent components of many recycling agents and rejuvenators commonly used in the asphalt industry, its effect on performance characteristics of asphalt binder has not been thoroughly understood. This paper uses combination of computational and experimental approach to study properties of aged asphalt binder specimens in presence of 1, 3, 5 and 10% paraffin wax. Differential scanning calorimetry (DSC) showed introduction of paraffin wax to aged asphalt significantly reduced glass transition temperature of aged asphalt, with 10% wax-doped aged asphalt having 9 degrees lower glass transition temperature than the control asphalt. The above observations can be attributed to plausible role of straight alkane chains of wax to disturb asphaltene clusters and increase overall asphaltene mobility. The latter was also reflected in wax-doped aged asphalt’s rheology with its percent recovery reducing by 50% in presence of 10% wax compared to the control. Thermo-gravimetric analysis (TGA) showed that addition of wax to aged asphalt binder increased the onset temperature of degradation; an increase of 25 degrees was recorded when wax dosage was increased from 1 to 10%. However, the overall thermal stability of asphalt binder was reduced as evidenced by the lower residual mass in samples with higher wax content. In addition, the difference in critical cracking temperatures (determined based on stiffness and stress relaxation ability of the asphalt binder) increased as the wax content increased. This in turn indicates cracking properties of wax-doped binder is controlled mainly by stiffness rather than stress relaxation ability. The latter could be attributed to formation of lamellar in wax-doped asphalt causing significant increase in stiffness. Molecular dynamics simulations results revealed how paraffin wax molecules change overall aggregation pattern of aged asphalt binder as evidenced by reduced formation of nano-aggregates in oxidized asphaltene in presence of wax molecules. The latter was described via a three-step mechanism including attraction of wax molecule to nano-aggregates of oxidized asphaltene, its penetration to self-assembled asphaltene stack, and disturbing formation of parallel stacks. Accordingly, the results showed the average aggregation number reduced after adding paraffin wax molecules to an equilibrated system of oxidized asphaltene molecules. Furthermore, radial distribution function confirmed that after addition of paraffin wax molecules, formation of parallel stacks of oxidized asphaltene is less likely. Molecular level understanding of wax-asphaltene interaction helps explain how wax contents of warm-mix additives, recycling agents and rejuvenators commonly used in asphalt industry can impact performance characteristics of asphalt binder.]]></description>
      <pubDate>Sat, 02 Mar 2019 15:41:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1572302</guid>
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    <item>
      <title>Investigation of Glass Transition Temperature of Asphalt Concrete</title>
      <link>https://trid.trb.org/View/1571584</link>
      <description><![CDATA[The presented manuscript identifies the mix design parameters important for the glass transition temperature and thermo-volumetric properties of asphalt–concrete mixes. A number of compacted specimens were prepared at different air-void content, by mixing different composition of materials in terms of aggregate origins, asphalt types, and gradations. The compacted mixes were later sized to required dimensions and were subjected to a uniform rate of cooling in a specially designed testing machine. The contraction of the sample during the cooling was measured by linear vertical displacement transducers, and the recorded values obtained were converted into longitudinal strain. All variables investigated in the study were found statistically significant to impact the glass transition temperature of asphalt paving mixes. The methodology adopted in this study provides a new approach to predict glass transition temperatures in asphalt–concrete mixes and identifies the mix parameters that will be helpful in delaying the glass transition temperature of the mix for reliable performance of asphaltic pavements in cold regions.]]></description>
      <pubDate>Fri, 25 Jan 2019 10:31:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1571584</guid>
    </item>
    <item>
      <title>Analytical investigation of the impact of a novel bio-based recycling agent on the colloidal stability of aged bitumen</title>
      <link>https://trid.trb.org/View/1468368</link>
      <description><![CDATA[While many additives have been used to modify the properties of aged bituminous materials to ensure long-term durability in highly recycled pavements, consensus on the definition of “rejuvenation” and the associated mechanisms does not exist. Thus, further clarification and assessment of impacts on ageing and of various approaches to “rejuvenation” are imperative. The present study utilises chemical fractionation, differential scanning calorimetry, and atomic force microscopy to evaluate the impact of a chemically modified vegetable oil-based recycling agent in terms of bitumen colloidal stability and phase compatibility. The Colloidal Instability Index (CII) is shown to be a useful parameter for monitoring the effect of ageing on rejuvenated bitumen. The rejuvenator tested in this study showed good ageing stability as indicated by the relatively limited increase in CII due to ageing. Differential scanning calorimeter thermal analysis of the bitumen showed an improvement in the glass transition of aged bitumen through the use of rejuvenators. Extended Bending Beam Rheometer testing at isothermal conditions around the glass transition temperature showed that the rejuvenator effect is not affected by physical hardening. The results are used to support a proposed categorisation of the impact mechanisms of recycling agents.]]></description>
      <pubDate>Tue, 27 Jun 2017 16:10:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468368</guid>
    </item>
    <item>
      <title>Effect of Mineral Fillers on the Oxidative Aging of Asphalt Binders: Laboratory Study with Mastics</title>
      <link>https://trid.trb.org/View/1338042</link>
      <description><![CDATA[Aging of asphalt binders is induced by chemical or physicochemical changes during production of pavement and throughout its service life. Although binder aging in pavement always occurs while binders are in contact with aggregates and mineral filler, in most laboratory aging studies and in current specifications, asphalt binders are individually aged without accounting for aggregate induced interactions. Past research has had conflicting findings, as it attributes mitigating or catalytic effects to the presence of mineral fillers in asphalt binders with oxidative aging. Thus, in the present study it was hypothesized that evaluation of asphalt oxidative aging without taking into account the interactive effect of the presence of mineral fillers was inadequate as a specification tool. The effect of mineral fillers on oxidative aging of asphalt was investigated with accelerated aging of mastics (asphalt and fillers) in a pressure aging vessel (PAV) and by measuring the changes in stiffness and glass transition temperature (Tg). The testing matrix included an aging evaluation of mastics containing different fillers, mineralogy, and surface area. The results showed that the low-temperature behavior of aged mastic could be modified by controlling filler concentration and type. The fillers acted as an agent adsorbing heavy fractions of asphalt binder and therefore reduced stiffness and changing Tg. During oxidative aging of asphalt binders and mastics, diffusion and adsorption mechanisms played a role in the rate of aging of asphaltic material. The results provided insight on the potential for selecting a mineral filler concentration and mineralogy type to reduce the impact of oxidative aging and possibly improve the service life of pavement.]]></description>
      <pubDate>Sat, 17 Jan 2015 17:28:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1338042</guid>
    </item>
    <item>
      <title>Influence of Physical Hardening on the Low-Temperature Properties of Bitumen and Asphalt Mixtures</title>
      <link>https://trid.trb.org/View/1253909</link>
      <description><![CDATA[A laboratory study was carried out on the effects of physical hardening on the low-temperature performance of bitumen and corresponding asphalt mixtures. Bitumen testing involved measurements of glass transition temperature and creep stiffness at various isothermal storage times. Mixture testing included evaluation of glass transition temperature, thermal stress build-up in restrained conditions and thermal strains in non-restrained conditions. A physical hardening rate was introduced both for bitumen and mixtures (PHRB and PHRM). Results indicated that glass transition temperatures can be reduced passing from bitumen to mixtures and a correlation can be found between the hardening rates PHRB and PHRM.]]></description>
      <pubDate>Wed, 03 Jul 2013 11:22:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/1253909</guid>
    </item>
    <item>
      <title>The effect of bitumen polar groups adsorption on mastics properties at low temperatures</title>
      <link>https://trid.trb.org/View/1252812</link>
      <description><![CDATA[The current design standard for asphalt mixtures provides guidance on selection of aggregates and asphalt binder and includes requirements for the amount of mineral filler to be added in the mix. In the SuperPave system, the amount of filler that can be included is limited to a ratio in the range of 0.6-1.2 by mass of the filler to the binder (i.e. approximately 20-40% by volume of mastic). However, this range is based on experience rather than on scientific evaluation of the interaction between filler and binder. The experimental results collected in this study for mastics produced with two bitumens and a set of commonly used fillers indicate that the physico-chemical interaction effect is the result of adsorption of asphaltenes and resins (i.e. polar groups in asphalt) on the surface of the filler particles. This adsorption is partially responsible for the changes in the mechanical properties (e.g. stiffness and viscosity) and thermo-volumetric properties (e.g. coefficients of thermal contraction and glass transition temperature - T g) of the mastic. The amount of polar groups adsorbed was found to depend on the Braunauer-Emmett-Teller (BET) surface area of the filler, but not on the chemical composition of the filler or the bitumen. The higher the BET surface area, the greater the amount of polar groups adsorbed, and the lower the glass transition temperature. The significant reduction in the glass transition temperature indicates that this adsorption phenomenon results in softening the bitumen in the mastics.]]></description>
      <pubDate>Fri, 28 Jun 2013 09:26:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1252812</guid>
    </item>
    <item>
      <title>Measuring physico-chemical interaction in mastics using glass transition</title>
      <link>https://trid.trb.org/View/1147351</link>
      <description><![CDATA[The current design standard for asphalt mixtures provides guidance on selection of aggregates, asphalt binder and includes requirements for the amount of mineral filler to be included. The amount of filler that can be included is limited to a ratio in the range of 0.6-1.2 by mass of the binder. However, this range is based on experience rather than on scientific evaluation of the interaction between filler and binder. Although many researchers acknowledge the physico-chemical interaction between asphalt binder and the mineral filler, currently a procedure to quantify this interaction, and consider it in selecting favorable filler to binder ratio, is not available. In this paper, the effect of fillers on the glass transition temperature (T sub g) of the base binder was used to evaluate the physico-chemical interaction in mastics. The total reinforcement of the filler, which is measured in terms of relative viscosity of the filled binder to the unfilled binder, consists of two parts: mechanical and physico-chemical. The mechanical reinforcement part is calculated based on micromechanical models commonly used in the literature that take into account volume filling effects and particle-to-particle interactions. Physico-chemical reinforcement is estimated based on the change in the T sub g in both Williams-Landel-Ferry (WLF) and Arrhenius time-temperature shift models. The concept introduced in this study is evaluated by viscosity and dilatometric T sub g testing of three binders mixed with three different fillers, at different concentrations. Results show that the physico-chemical interaction between the mineral filler and the binder can be accurately estimated from the difference in the glass transition temperature of the mastics and the binder.]]></description>
      <pubDate>Tue, 28 Aug 2012 08:59:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1147351</guid>
    </item>
    <item>
      <title>Modeling Thermal Stress in Asphalt Mixtures Undergoing Glass Transition and Physical Hardening</title>
      <link>https://trid.trb.org/View/1130548</link>
      <description><![CDATA[Asphalt binders have been shown to undergo significant time-dependent stiffening when stored at low temperatures. This physical hardening has a significant effect on the laboratory performance of asphalt binders. However, the importance of isothermal conditioning for asphalt mixtures and its effect on thermal cracking performance have been a subject of significant debate. A theoretical approach accounting for the glass transition and physical hardening in the thermal stress buildup in mixtures was derived from relaxation modulus master curves, the William–Landel–Ferry equation, Boltzmann’s superposition principle, and a model describing the isothermal contraction of asphalt as a continuous function of conditioning time and temperature. With the model predictions, it is shown that thermal stress relaxation and stress buildup induced by physical hardening can continuously affect thermal stress throughout the cooling process. The cooling rate also affected the amount of delayed stress buildup that occurred after the temperature had stabilized at isothermal conditions as a result of physical hardening. A relatively simple device was developed and used for verification and support of the thermal stress model. Mixture measurements performed at different cooling rates and isothermal conditions supported the theoretical predictions. The findings clearly show that the effect of physical hardening on stress buildup in mixtures is measurable and important. Therefore, the glass transition of asphalts and their behavior under isothermal conditioning needs to be measured to better predict thermal cracking.]]></description>
      <pubDate>Mon, 25 Jun 2012 09:27:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1130548</guid>
    </item>
    <item>
      <title>Controlled telescopic reinforcement system of fabric-cement composites -- Durability concerns</title>
      <link>https://trid.trb.org/View/1083502</link>
      <description><![CDATA[The study objective was to modify the microstructure of AR glass strand to induce a controlled mode of telescopic bonding during service life, by using sub-micron particles absorbed between the filaments of the strand. Two groups of fillers were used: (i) pozzolanic fillers (silica fume) with 50 nm and 200 nm particle sizes; and (ii) polymeric fillers (polystyrene-based polymers), with two glass transition temperatures (- 6 °C and 100 °C). Composites were prepared using fabric reinforcement and tested for tensile behavior. Composite properties could be controlled by addition of fillers into the glass bundle, and the magnitude and efficiency of the modification was highly dependent on the filler type, structure, and properties. The best performance was obtained with silica fume fillers having relatively large 200 nm particles.]]></description>
      <pubDate>Mon, 20 Dec 2010 15:48:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1083502</guid>
    </item>
    <item>
      <title>Characterizing the Low-Temperature Performance of Hot-Pour Bituminous Sealants Using Glass Transition Temperature and Dynamic Stiffness Modulus</title>
      <link>https://trid.trb.org/View/906310</link>
      <description><![CDATA[Joint and crack sealants exposed to cold climates experience high tensile stresses. Sealants should have the ability to dissipate these stresses to perform their function properly. In cold climates, the state of sealing materials may change from rubbery to solid state due to low in-service temperatures. As a result, sealants become stiffer and less capable of dissipating the induced tensile stresses. This paper introduces a laboratory characterization method for joint sealants based on dynamic testing at low-temperatures. The dynamic mechanical analyzer test was conducted on seven hot-pour bituminous sealants in the temperature-sweep mode to characterize the stiffness-temperature behavior of sealants. Glass transition temperature, which is the boundary temperature between rubbery and solid states, was estimated for each sealant. Glass transition temperature and low-temperature stiffness can be used to predict the field performance of sealants, and to evaluate the compatibility of a sealant to a certain environment.]]></description>
      <pubDate>Tue, 15 Dec 2009 15:00:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/906310</guid>
    </item>
    <item>
      <title>Physical Aging in Semi-Crystalline Asphalt Binders (With Discussion)</title>
      <link>https://trid.trb.org/View/891098</link>
      <description><![CDATA[Modulated differential scanning calorimetry was used to determine isothermal storage effect at -20 degrees C on the enthalpy relaxation and glass transition temperature in five asphalt binders. Glass transition temperature and enthalpy relaxation were found to increase linearly with the storage time logarithm suggesting asphalt property isothermal changes. The glass transition temperature increase rates increased linearly with the wax content. Data indicated a strong effect of physical aging on mechanical properties after one asphalt binder was subjected to dynamic mechanical analysis. There was calculation of µ, the rate of physical aging, and discussion of the relation of µ to the amount of glassy domain. Even after heating 30 degrees C above the storage temperature, the effect of physical aging persisted. There was consideration of the presence of a rigid amorphous phase, based on the calorimetric and rheological evidence. That the ability of the binder to relax stresses decreases with time under isothermal conditions is indicated by characteristic relaxation times, which were found to increase with isothermal storage time.]]></description>
      <pubDate>Tue, 30 Jun 2009 08:32:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/891098</guid>
    </item>
    <item>
      <title>Effect of Bituminous Material Rheology on Adhesion</title>
      <link>https://trid.trb.org/View/868653</link>
      <description><![CDATA[Bituminous materials are used in many civil engineering applications in which adhesion to a substrate is essential for good performance. Yet it is not possible to predict the adhesion of these materials. The particular case of bituminous crack sealants is of interest; the effect of sealant viscosity, aging, test temperature, and loading rates was investigated by means of a blister test. This test provided the bonding characteristics to a model aggregate in relation to interfacial fracture energy (IFE). From testing of several sealants, it was found that pouring viscosity affects adhesion and that higher viscosities help to attain higher IFEs. Temperature was found to play a key role on bonding characteristics and failure mechanism because it affected the viscoelastic properties of the sealant. The glass transition temperature (Tg) was found to have a governing role on bonding characteristics. At temperatures above Tg, bond strength was found to be affected by sealant flow such that failure was flow related; that is, cohesive failure prevailed. At temperatures below the Tg, at which sealants were stiff and bulk deformation was low, stress was directed toward the interface so that failure tended to be adhesive. In taking into account temperature and test rates, an IFE master curve was obtained for a sealant. Such a curve may be used in predicting and comparing sealant IFE.]]></description>
      <pubDate>Wed, 20 Aug 2008 14:29:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/868653</guid>
    </item>
    <item>
      <title>Glass Transition Temperature and Low-Temperature Stiffness of Hot-Pour Bituminous Sealants</title>
      <link>https://trid.trb.org/View/848576</link>
      <description><![CDATA[Joint and crack sealants exposed to cold-climates experience high tensile stresses. Sealants should have the ability to dissipate these tensile stresses to perform their function properly. In cold climates, the state of sealing materials may change from rubbery to solid state due to low in-service temperatures. As a result, sealants become stiffer and less capable of dissipating the induced tensile stresses.  This paper introduces a laboratory evaluation method for joint sealants based on dynamic testing at low temperatures. Dynamic Mechanical analyzer (DMA) test was conducted on seven hot-pour bituminous sealants using the temperature sweep mode to characterize the stiffness-temperature behavior of sealants. Glass transition temperature (Tg), which is the boundary temperature between rubbery and solid states, was estimated for each sealant. Glass transition temperature and low-temperature stiffness can be used to predict the field performance of sealants, and evaluate the compatibility of a sealant to a certain environment.]]></description>
      <pubDate>Mon, 03 Mar 2008 09:00:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/848576</guid>
    </item>
    <item>
      <title>Parameters Governing the Corrosion Protection Efficiency of Fusion-Bonded Epoxy Coatings on Reinforcing Steel</title>
      <link>https://trid.trb.org/View/849776</link>
      <description><![CDATA[The purpose of this study was to investigate various epoxy coating and exposure parameters to determine their effects on the corrosion of reinforcing steel. The parameters investigated were: chloride content at the bar depth, coated bar corroded area, corrosion product color under the coating, epoxy coating adhesion, coating color, coating damage (holidays and holes), coating thickness, TGA (moisture content), DSC (glass transition temperature) and energy dispersive spectrometry (EDS) analysis and scanning electron microscopy (SEM) coating cracking investigation. This study demonstrated that the epoxy coated reinforcing steel (ECR) coating samples extracted from concrete exhibited extensive cracking compared to the new ECR samples in which the coating cracking was limited to only one sample. The coating cracking correlated with the amount of chloride at bar level, residual adhesion of the epoxy to the steel surface, and the percent moisture in the coating. The coating cracking is also related to the change in color of the epoxy and indicates that the epoxy coating degradation in concrete influences the surface condition of the coating. The DSC results showed that both the extracted epoxy coating samples as well as new samples are not fully cured during the manufacturing process. Additionally, the extracted epoxy coated samples investigated presented significant permanent adhesion loss with little or no epoxy coating residue present on the bar surface, while the EDS analysis showed that once adhesion is lost, corrosion will proceed unimpeded under the coating even in the absence of chlorides. The parameters that presented a direct correlation with the observed corrosion activity were the number of holidays and the number of damaged areas per unit length of bar. The results also show a distinct loss of quality control in the handling and possibly storage of new coated bars. The new ECR samples had significantly higher damage density than the samples extracted from concrete, while there was no change in the number of holidays and cure condition.]]></description>
      <pubDate>Thu, 21 Feb 2008 15:58:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/849776</guid>
    </item>
    <item>
      <title>Investigation of the Fracture Resistance of Hot-Mix Asphalt Concrete Using a Disk-Shaped Compact Tension Test</title>
      <link>https://trid.trb.org/View/778609</link>
      <description><![CDATA[In recent years the transportation materials research community has focused a great deal of attention on the development of testing and analysis methods to shed light on fracture development in asphalt pavements. Recently it has been shown that crack initiation and propagation in asphalt materials can be realistically modeled with cutting-edge computational fracture mechanics tools. However, much more progress is needed toward the development of practical laboratory fracture tests to support these new modeling approaches. The goal of this paper is twofold: (a) to present a disk-shaped compact tension [DC(T)] test, which appears to be a practical method for determining low-temperature fracture properties of cylindrically shaped asphalt concrete test specimens, and (b) to illustrate how the DC(T) test can be used to obtain fracture properties of asphalt concrete specimens obtained from field cores following dynamic modulus and creep compliance tests performed on the same specimens. Testing four mixtures with varied composition demonstrated that the DC(T) test could detect the transition from quasi-brittle to brittle fracture by testing at several low temperatures selected to span across the glass transition temperatures of the asphalt binder used. The tendency toward brittle fracture with increasing loading rate was also detected. Finally, the DC(T) test was used in a forensic study to investigate premature reflective cracking of an isolated portion of pavement in Rochester, New York. One benefit of the DC(T) test demonstrated during testing of field samples was the ability to obtain mixture fracture properties as part of an efficient suite of tests performed on cylindrical specimens.]]></description>
      <pubDate>Thu, 23 Mar 2006 09:19:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/778609</guid>
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