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    <title>Transport Research International Documentation (TRID)</title>
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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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      <title>Study on the preparation and modification mechanism of GO/SBR composite modified emulsified asphalt</title>
      <link>https://trid.trb.org/View/2558474</link>
      <description><![CDATA[This paper employs graphene oxide (GO) and anionic styrene-butadiene rubber (SBR) latex as modifiers for road-emulsified asphalt. A silane coupling agent (KH550) is used to modify GO, resulting in the development of a novel GO/SBR composite-modified emulsified asphalt. A mathematical model was optimized to determine the optimal material ratio, which was verified through performance tests. Techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were utilized to investigate the modification mechanism. The results indicated that both the median particle size and storage stability of the GO/SBR composite-modified asphalt were enhanced, with significant improvements in mechanical properties compared to ordinary emulsified asphalt. Microscopic analysis revealed enhanced dispersion of modified GO in asphalt, and the interaction between modified GO and emulsified asphalt was determined to be purely a physical reaction. This study provides valuable insights into the application of GO in road engineering.]]></description>
      <pubDate>Thu, 26 Jun 2025 11:42:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2558474</guid>
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    <item>
      <title>Improving Railway Track Durability: Evaluating Sand and Emulsion Effects on Cement Asphalt Mortar</title>
      <link>https://trid.trb.org/View/2528606</link>
      <description><![CDATA[The degradation of railway substructures due to fouled ballast is a critical concern in railway infrastructure management. This study explores the use of Cement Asphalt Mortar (CAM) as a novel stabilizing agent to address fouled ballast issues. The research systematically examines the influence of sand content and various emulsifiers on CAM’s engineering properties through comprehensive testing. Notably, anionic and nonionic emulsifier mixtures exhibited exceptional stability, with residue content ranging from 0.5% to 4%, while cationic emulsifier mixtures showed higher residue content (9% to 14%). Moreover, the inclusion of sand significantly enhanced CAM mixture strength, with a Sand/Cement (S/C) ratio of 50% demonstrating the highest strength, reaching 0.35 MPa after 2 hours and substantial strength gains over 28 days of curing. Dynamic modulus testing underscored the favorable impact of sand content, particularly at lower temperatures, emphasizing the importance of sand and emulsifier types in improving CAM’s engineering properties.]]></description>
      <pubDate>Thu, 24 Apr 2025 10:39:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528606</guid>
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    <item>
      <title>Influence of replacing Portland cement with anionic asphalt emulsion on vibration damping, mechanical and microstructural properties of concrete</title>
      <link>https://trid.trb.org/View/2445486</link>
      <description><![CDATA[The effect of anionic asphalt emulsion (AE) as partial replacement of Portland cement to enhance the damping properties of concrete was examined. Five concrete mixtures were designed and prepared, increasing AE content from 0 % to 40 % in overall binder volume, in 10 % increments. Loss factor, dynamic moduli, resonant frequencies, and compressive strength were obtained at the age of 7, 28, 90, and 180 days. Results show that the loss factor of concrete increased as the asphalt content increased, whereas the dynamic modulus and resonant frequency decreased. In addition to the viscous damping contributed by asphalt droplets, the more porous microstructure and weaker interfacial transition zones in AE modified concrete can also enhance the damping properties. However, an inverse correlation between concrete strength and damping can be observed with increasing AE content, where the substitution of AE results in a significant decrease in the compressive strength of concrete. Therefore, the anionic AE modified concrete seems to be more suitable for non-structural application where strength is not a key requirement.]]></description>
      <pubDate>Mon, 18 Nov 2024 17:09:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2445486</guid>
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    <item>
      <title>Crushed rock treated with anionic bituminous emulsion for construction of unsealed roads in Australia with enhanced long-term performance</title>
      <link>https://trid.trb.org/View/2369703</link>
      <description><![CDATA[One of the innovative applications of bituminous emulsions is their use in unsealed road construction and rehabilitation by merging with crushed rock, producing a composite material with enhanced rutting resistance and dust suppression qualities. In this study, a series of wheel tracking (WT) tests and constant lateral stiffness tests (CLST) using a precision unbound material analyser (PUMA) were conducted on crushed rock treated with bituminous emulsion (CR-BE) to examine the efficiency of the composite. The results from the WT tests showed that treaded tires result in a higher degree of rutting compared to smooth tires, while still being lesser in magnitude in CR-BE compared to untreated crushed rock. CR-BE with 3% bituminous emulsion had the lowest rutting. The rutting data from WT tests were used to analyse the permanent deformation data from CLST tests.]]></description>
      <pubDate>Fri, 17 May 2024 09:20:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2369703</guid>
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      <title>How calcium and magnesium ions affect the stability of asphalt with anionic emulsifiers: A molecular dynamics study</title>
      <link>https://trid.trb.org/View/2228262</link>
      <description><![CDATA[Based on molecular dynamics, modelling and analysis of the state of salt-free ionic emulsified asphalt system with the addition of calcium ions and magnesium ions (Ca²+and Mg²+, respectively). The effect of calcium and magnesium ions on the stability of sodium dodecyl sulfate (SDS)-emulsified asphalt was investigated. To determine the effect of the metal cations on the stability of anionic emulsified asphalt, the interfacial morphological distribution, interaction of the emulsifier with water molecules, and mobility of water molecules in the emulsifier head group/metal cations was investigated. The results of the simulation analysis show that, compared to a salt-free environment, the addition of Ca²+ or Mg²+ to a salt-containing system induces aggregation between the head groups of the SDS emulsifier molecules and reduces the thickness of the SDS emulsifier headgroup distribution along the Z-axis. This, in turn, weakens the stability of the anionic emulsified asphalt. Compared to the Ca²+-emulsified asphalt system, the Mg²+-emulsifier headgroup molecules are more easily bound to water molecules and more difficult to dissociate from them. Thus, the addition of Mg²+ is more likely to reduce the stability of the emulsion. Furthermore, the results of the simulated data analysis indicate that the addition of cations to the emulsified asphalt system, particularly Mg²+, reduces the mobility of the water molecules surrounding the head group, thereby reducing the stability of the emulsion. The results of the molecular simulations are consistent with the experimental results in the literature. Thus, the validity of using molecular dynamics to analyze the effect of metal cations on anionic emulsified asphalt was verified.]]></description>
      <pubDate>Mon, 11 Sep 2023 11:42:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2228262</guid>
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    <item>
      <title>Effect of phenyl functional group on the demulsification process of dodecyl anion emulsified asphalt</title>
      <link>https://trid.trb.org/View/2028368</link>
      <description><![CDATA[The demulsification of emulsified asphalt is required to form the adhesion of the asphalt. Using conductivity experiments and validated molecular dynamics simulations, this paper investigated the micro-mechanism of the demulsification process of emulsified asphalt. The results show that the phenyl functional group causes a decrease in the diffusion coefficient of the SiO₂ aggregate system and an increase in its interfacial energy, whereas an inverse tendency occurs in the CaCO₃ aggregate system, which significantly affects the demulsification rate and adhesion between the emulsified asphalt and aggregates. The electrostatic force between Na+ and CaCO₃ allows the emulsifiers to adsorb well to the aggregates, and the demulsification time can be controlled by adjusting the relative content of phenyl functional groups and Na+. The adsorption rate and the adsorption amount of dodecyl anion emulsified asphalt on the aggregate surface grow with increasing phenyl functional group content, leading to a faster demulsification rate of the system and enabling the demulsification rate of the SiO₂ emulsified asphalt system to be greater than that of the CaCO₃ system. This research demonstrates that the demulsification process of emulsified asphalt can potentially be adjusted by managing the relative content of Na+ and phenyl functional groups in the emulsifier, which gives critical insight into improving the design and construction of asphalt pavements.]]></description>
      <pubDate>Fri, 18 Nov 2022 15:40:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2028368</guid>
    </item>
    <item>
      <title>Experimental investigation of optimum adhesion properties for anionic emulsions in road maintenance applications</title>
      <link>https://trid.trb.org/View/1876931</link>
      <description><![CDATA[Anionic emulsions are widely used in North America for road maintenance applications but are less popular in Europe. Due to their distinctive characteristics, the use of anionic emulsions is advantageous when local aggregate is excessively dusty and the cost to wash them to meet requirements would be too expensive. However, anionic emulsions’ compatibility, in terms of adhesion, with certain types of aggregate is reported to be limited. This paper presents the results of an experimental study that was conducted firstly to investigate the effect of aggregate mineralogy on the degree of adhesion (i.e. the bond) between the aggregate and the bitumen using anionic and cationic bitumen emulsions, and secondly to evaluate the potential development and use of new adhesion agents/anti-strips for anionic rapid-set emulsions used in chip seal applications. For this purpose, the degree of adhesion that was achieved between the emulsions used and a range of selected aggregates was measured by means of a series of internationally recognised laboratory adhesion tests.The experimental laboratory work confirmed that the degree of adhesion between the aggregate and emulsion is governed to a large extent by aggregate mineralogical composition and, in particular, its associated electrostatic interaction with a given emulsion. The results obtained indicated that a higher degree of adhesion was achieved when an aggregate was combined with an emulsion possessing the opposite surface charge. Further laboratory test results suggest that the addition of amine-based adhesion agents to an anionic emulsion can significantly improve its degree of adhesion with aggregates possessing an electro-negative surface charge.]]></description>
      <pubDate>Fri, 29 Oct 2021 15:40:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1876931</guid>
    </item>
    <item>
      <title>Modified bitumen emulsion by anionic polyurethane dispersion nanocomposites</title>
      <link>https://trid.trb.org/View/1723584</link>
      <description><![CDATA[Different materials and compounds were used for improving mechanical and rheological properties of bitumen. Replacing the traditional bitumen by emulsion bitumen is increasing due to reduced environmental pollution. In recent years, emulsion bitumen modification has been considered to obtain higher efficiency bitumen with water-dispersible polymers. For this purpose, this study intends to investigate the modification of emulsion bitumen using water-dispersible anion polyurethane nanoclay nanocomposite. Since the polymer elasticity property plays an important role in bitumen modification and its properties, anionic polyurethane with different elastic properties was prepared by changing its structure, and its effects on modifying bitumen emulsion were investigated. Preliminary tests of bitumen properties and rheological behaviour analysis were performed on the prepared samples. The results of the tests showed that the penetration-modified bitumen decreased and softening point increased. As the structure of modifier changes, the rheological behaviour of bitumen is improved and changes from viscous to elastic one.]]></description>
      <pubDate>Mon, 17 Aug 2020 09:35:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1723584</guid>
    </item>
    <item>
      <title>A Report on the Fabrication of Concrete Pavement with the Application of Anionic Bitumen Emulsion</title>
      <link>https://trid.trb.org/View/1541896</link>
      <description><![CDATA[The problems of concrete degradation in pavements occur around the world, regardless of climatic zones, which is one of the chief factors in environmental corrosion. This article describes the final stage of Development Project No. 14009 03 carried out by the Ministry of Science and Higher Education in Poland regarding the verification of laboratory research results with the construction of the Multimodal Reload Terminal within the Duty Free Zone in Małaszewicze, Poland. The Terminal concrete pavement was designed to expand and doweled in accordance with the national requirements and the paving layers was based on existing solutions. Concrete in the slab was modified with an anionic bitumen emulsion to reduce its water absorption and improve resistance to environmental aggression. To achieve the required consistency of the concrete mix superplasticizers were used. The use of bitumen emulsion allowed to achieve the concrete water absorbability to below 4% in comparison to reference concretes while at the same time retaining high F200 frost resistance. The technology of cement composites modified with anionic bitumen emulsion was successfully tested under real operating conditions with the creation of a concrete pavement capable of bearing high mechanical pressure in a corrosive environment.]]></description>
      <pubDate>Mon, 22 Oct 2018 09:18:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/1541896</guid>
    </item>
    <item>
      <title>Retardation Mechanism of Anionic Asphalt Emulsion on the Hydration of Portland Cement</title>
      <link>https://trid.trb.org/View/1502265</link>
      <description><![CDATA[Cement-asphalt (CA) mortar, a grouting material consisting of Portland cement (PC), asphalt emulsion, sand, water and other related admixtures, has been widely used as a cushion layer material in the construction of High-Speed Railways (HSR) during the past decade in China due to its excellent damping property. The fresh and hardened properties of CA mortar are closely related to the PC hydration in the presence of asphalt emulsion. However, the retardation effect introduced by the anionic asphalt emulsion on the hydration process of PC has not been fully understood. In this paper, the effect of an anionic asphalt emulsion on the early hydration process of CA paste was first investigated by setting time test, isothermal conduction calorimeter and electrical resistivity. The MIP and SEM were then employed to characterize the microstructure evolution of the CA paste. Based on the data and observation obtained from the experimental study, three possible retardation mechanisms introduced by the anionic asphalt emulsion on the PC hydration were then assessed in this paper, including (i) selective adsorption by anionic emulsifier via electrostatic attraction, (ii) coating formed by the demulsification of anionic asphalt emulsion, and (iii) reduced reactivity of water molecules in anionic asphalt emulsion.]]></description>
      <pubDate>Wed, 25 Apr 2018 11:15:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1502265</guid>
    </item>
    <item>
      <title>BITUMEN AND WATER DO MIX</title>
      <link>https://trid.trb.org/View/728109</link>
      <description><![CDATA[Emulsification, which is the dispersion of one immiscible liquid in another, is a safe and cost-effective way of converting bitumen into a practical and effective binder for road maintenance products.  This article offers a guide to bitumen emulsions and explains why and how emulsification is used. Bitumen emulsion can be described as a liquid product in which bitumen is dispersed throughout the continuous water phase in the form of discrete globules, which are held in suspension by electrostatic charges produced by an emulsifier.  One of the most significant improvements to bitumen emulsions has been the development with emulsifying agents, of which there are two types:  anionic and cationic.  Bitumen emulsions employing cationic emulsifiers adhere much better to chipping than anionic emulsifiers.  Bitumen emulsions can be modified with polymers, which provide increased performance properties over a wider temperature range and offers better results for highly stressed roads.  The production of rapidly setting products provides a more controlled break of the emulsion and longer overall design life.  Emerging technological developments are discussed.]]></description>
      <pubDate>Fri, 08 Nov 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/728109</guid>
    </item>
    <item>
      <title>PROCEEDINGS OF THE THIRD UMTA R&amp;D PRIORITIES CONFERENCE, CAMBRIDGE, MASSACHUSETTS, NOVEMBER 1978. VOLUME V: UMTA SPECIAL TECHNOLOGY PROGRAMS WORKSHOPS</title>
      <link>https://trid.trb.org/View/142424</link>
      <description><![CDATA[This is a compilation of material that was presented at the Third UMTA R&D Priorities Conference Workshops on UMTA Special Technology Programs.  Part I deals with safety, qualification, and life-cycle costing, and includes discussions of rail transit safety and product qualification.  Part II--consumer inquiry technology, National Cooperative Transit R&D Program, and technology program--includes discussions of consumer need for information on transit availability, the National Cooperative Transit R&D Program (NCTRP), the technology sharing program, and transit marketing.  This volume contains six resource papers which can be found summarized in Volume I of this report along with summaries of other workshop sessions.  Volume I also includes the proceedings of the general sessions and a listing of conference participants.  These proceedings (Rpt. Nos. UMTA-DC-06-0157-79-1 thru UMTA-DC-06-0157-79-9) consist of nine separately titled volumes, namely: Volume I: Proceedings of General Sessions and Summarized Reports of Workshops; Volume II: Bus and Paratransit Technology Workshops; Volume III: AGT and Advanced Systems Workshops; Volume IV: Service and Methods Demonstration Workshops; Volume V: UMTA Special Technology Programs Workshops; Volume VI: Rail and Construction Technology; Volume VII: Transit Management Workshops; Volume VIII: Access for Elderly and Handicapped Persons Workshops; and Volume IX: Urban Transportation Planning Workshop.]]></description>
      <pubDate>Wed, 30 Jan 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/142424</guid>
    </item>
    <item>
      <title>MIX DESIGN USING ASPHALT MILLINGS</title>
      <link>https://trid.trb.org/View/672635</link>
      <description><![CDATA[A field demonstration project was undertaken by the Oklahoma Department of Transportation to investigate the performance of an asphalt overlay constructed using recycled asphalt millings and the cold mixed, cold laid system.  A 1.9-km (1.2-mi) section of the US-64 North frontage road in Pawnee County was rehabilitated with a 5-cm (2-in.) thick overlay using 100% recycled asphalt millings.  The section was divided into four approximately equal length test sections.  A different type of emulsion was used to rejuvenate the asphalt millings for each test section.  The purpose was to determine the relative performance of each emulsion type and construction method used in this recycled asphalt pavement (RAP) project.  A laboratory investigation was carried out to accomplish two major tasks: the first task was to determine the optimum emulsion and moisture contents of RAP mixes prepared with four different types of emulsions; the second task was to investigate the effect of adding portland cement to RAP mixes, thus producing a cement-emulsion composite.  One of the objectives of this study was to document the behavior of RAP mixes as affected by the addition of portland cement, and to find the optimum emulsion and cement contents.  Achieving an adequate compaction is crucial to the successful performance of a cold mixed, cold laid overlay.  The degree of compaction can greatly vary depending upon rolling pattern, speed, equipment, compaction dynamics, and characteristics of RAP mixes.  From post-construction site visits, it was evident that the polymer modified anionic (PMA) emulsion section performed better than the other sections.  A PMA mix containing 2% free moisture and 2% emulsion was found to have the highest dry stability value; however, this mix had a lower retained stability than a comparable mix prepared with polymer modified cationic (PMC) emulsion.  For samples prepared from cement-emulsion composite, both dry and soaked stability values increased as cement content increased.  The addition of portland cement, however, affected the stability value of samples cured under soaked conditions much more than those cured under dry conditions.  The introduction of as little as 1% of portland cement to RAP mixes doubled the retained stability of specimens, as compared with a RAP mix rejuvenated with high float emulsion (HFE-300).  The cold mixed, cold laid process of pavement rehabilitation holds significant promise for the future.  The current technology, however, needs improvement and refinement through further laboratory and field studies.]]></description>
      <pubDate>Fri, 09 Feb 2001 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/672635</guid>
    </item>
    <item>
      <title>DESIGN AND EVALUATION OF COLD IN-PLACE RECYCLED PAVEMENTS</title>
      <link>https://trid.trb.org/View/497061</link>
      <description><![CDATA[Cold In-Place Recycling appears to be a cost effective rehabilitation method for some flexible pavements.  However, difficulties exist in constructing projects due to non-standard mixture design and analysis techniques.  As a part of the cold mix recycling process, the old and aged mix is milled out and is mixed with a virgin aggregate and additional asphaltic rejuvenator to make the recycled mix meet the standard specifications.  The recycling agents or rejuvenators for cold mixes are emulsified asphalts, either cationic (CMS) or anionic with high-float characteristics (HFRA).  The mix design for cold mixes containing emulsified asphalts is significantly different from the conventional hot asphalt mixes.  Currently, there is no standard procedure for design of cold emulsified asphalt recycled mixes.  The objectives of this study were to:  (1) Develop a methodology for cold mix design using CMS and HFRA emulsions as recycling agents; (2) Evaluate and characterize these cold mixes in the laboratory and compare the likely performance with the conventional hot asphalt mixes; (3) Through laboratory characterizations, evaluate the structural contribution of cold recycled mixes in pavements; and (4) Develop guidelines for design and construction of cold mix binder layers.]]></description>
      <pubDate>Tue, 06 Apr 1999 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/497061</guid>
    </item>
    <item>
      <title>CLAY MINERALS USED TO AID THE FORMATION OF BITUMEN EMULSIONS (IN GERMAN)</title>
      <link>https://trid.trb.org/View/95181</link>
      <description><![CDATA[THAT CLAYS AS WELL AS SOAPS AND ORGANIC AMMONIUM SALTS CAN BE USED TO PRODUCE ANIONIC OR CATIONIC BITUMEN EMULSIONS IS ESTABLISHED. THE EXCHANGE PROPERTIES OF THE CLAYS WERE EXAMINED BY THE AMMONIUM ACETATE METHOD AND X-RAY ANALYSIS. OTHER THEMES DISCUSSED INCLUDE THE ACTION OF THE CLAY DURING EMULSIFICATION, THE BREAKING OF AN ANIONIC BITUMEN EMULSION BY CLAY, INVESTIGATIONS OF BITUMENS TO DETERMINE THEIR CONTENT OF AMINES AND AMMONIA SALTS OR ACIDS, AND PRODUCTION OF EMULSIONS WITH DIFFERENT TYPES OF CLAYS. /RRL/]]></description>
      <pubDate>Thu, 27 Oct 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/95181</guid>
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