<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>
    </image>
    <item>
      <title>Laboratory Evaluation of Fatty Acid Amide Foaming Agent Foamed Asphalt Mixtures Containing Reclaimed Asphalt Pavement</title>
      <link>https://trid.trb.org/View/2630502</link>
      <description><![CDATA[Cold recycling technology for asphalt mixtures is an energy-efficient and environmentally friendly method, with foamed asphalt serving as a key material for enhancing performance. This study introduces foamed asphalt (BAF) obtained by adding fatty acid amide (FAA) foaming agent to base asphalt. The foaming characteristics of BAF were determined, and its adhesion and fatigue properties with aggregates were evaluated. A mix gradation with 60%–70% reclaimed asphalt pavement (RAP) admixture was designed. This study investigates the variations in the mechanical properties (tensile strength, compressive strength, and shear strength) of foamed asphalt cold recycled mixtures (FACRM) under different influencing factors. The results indicate that, compared to base asphalt, the adhesion performance of BAF with limestone improved by 21.4%, and the stripping time of RAP increased by 121.5%. Compared to conventional mixtures, the dry/wet splitting strength of the foamed asphalt mixture increased by 13.0% and 12.8%, while the tensile strength ratio (TSR) increased by 1.3%. The optimal values of foamed asphalt, water, curing temperature, and cement were 3%, 80%, 80°C, and 1.5%, respectively. The research findings contribute to the widespread application of foamed asphalt cold recycled mixtures, thereby improving resource utilization.]]></description>
      <pubDate>Tue, 17 Mar 2026 16:15:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2630502</guid>
    </item>
    <item>
      <title>Prediction of soil conditioner dosages for shield tunneling in sandy soil based on machine learning</title>
      <link>https://trid.trb.org/View/2649961</link>
      <description><![CDATA[Inadequate soil conditioning during Earth Pressure Balance shield (EPBS) tunneling in sandy strata frequently causes operational issues. This study developed a data-driven framework integrating 15 operational and geological parameters from Shenyang Metro Line 4. Using principal component analysis for dimensionality reduction and quantitative TPI/FPI criteria for dataset selection, and constructed SVR, XGBoost, and LightGBM models optimized via PSO, BO, and Optuna. The LightGBM-Optuna ensemble demonstrated superior performance, reducing prediction errors by 45–58 % compared to baseline configurations. Application to suboptimal datasets validated a 13.15 % reduction in specific energy consumption, demonstrating significant potential for intelligent tunneling control.]]></description>
      <pubDate>Thu, 15 Jan 2026 09:22:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2649961</guid>
    </item>
    <item>
      <title>Influence of fatty acid amide foaming agents on the foaming effect and rheological properties of foamed asphalt</title>
      <link>https://trid.trb.org/View/2484970</link>
      <description><![CDATA[Foamed asphalt technology is widely used in road construction due to its favorable environmental and economic impacts. This study explores the effects of fatty acid amide surfactants (FAA) foaming agents on asphalt performance. Modified asphalt (BAF) is produced by adding the FAA to the base asphalt (BA). The optimum foaming conditions for asphalt were determined by considering the effects of foaming temperature and water consumption on the asphalt foaming effect. Then, the changes in the foaming agent and the foaming process on the properties of asphalt are analyzed, such as basic properties, high and low-temperature rheological properties, and adhesion. Microscopic analysis methods revealed the key mechanisms affecting macroscopic performance during foaming. The results show that the foaming process reduces high and low temperature performance. However, the FAA foaming agent slightly increases asphalt's high-temperature critical failure temperature. Furthermore, the foaming agent improved the foaming effect of asphalt, enhancing its low-temperature performance and pull-out strength. Specifically, the foaming process of BAF is three times more effective than BA in improving the low-temperature performance of asphalt. The foaming agent increased tensile strength, with granite showing the largest increase at 29.6 % compared to limestone and basalt. In addition, the foaming process reduces adhesion. Microscopic analysis revealed that the uniform distribution of the foaming agent in the asphalt positively impacts its microstructure, contributing to improved long-term durability. The research results revealed the mechanisms by which the foaming agent and foaming process impact the overall performance of asphalt, providing experimental data and a theoretical basis for the optimization and application of foamed asphalt.]]></description>
      <pubDate>Tue, 18 Feb 2025 10:56:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2484970</guid>
    </item>
    <item>
      <title>Soil Conditioning for EPB Shield Tunneling in Coastal Silty Clay Strata: Laboratory Research and Field Application</title>
      <link>https://trid.trb.org/View/2310025</link>
      <description><![CDATA[Earth pressure balance (EPB) shield tunneling in coastal silty clay strata often faces the problems of clogging on the screw conveyor or the belt conveyor due to lumps of clay soils formed because of the large cohesion of clay particles. Soil conditioning using common foaming agents is not enough to alleviate the problem. Therefore, the novel dispersed foaming agent was studied in this work using performance and orthogonal compound tests. The foam microstructure was observed using an electron microscope to analyze the evolution mechanism of bubbles for different additives. Both laboratory and in situ tests were carried out to assess the effectiveness of the novel dispersed foaming agents. The testing results showed that 50 vol.% is an optimum foaming injection ratio to improve rheological properties and undrained shear strength of silty clay to avoid the unnecessary waste of conditioning materials. The half-life time (T1/2) and foam expansion ratio (FER) of novel foaming agents using the formation ionic solution as the solvent increased due to existing hydrophilic polar groups based on undisturbed soil samples taken from a Xiamen Metro construction site. It was shown that acids, alkalis, and salt ions had little effect on the FER and T1/2 of foaming agents (Foams A and B) using the macromolecular dispersant. The variations in the plasticity index were similar to those of the liquid limit for the muck conditioned using dispersed foaming agents with sodium citrate, sodium bicarbonate, and sodium chloride at a concentration of 0.1 wt%. Sodium bicarbonate had the most significant impact on the foaming agents' anticlay effect. Compared with commercial and house-made foaming agents of the Fuzhou Metro project, the muck was effectively conditioned by Foams A and B based on the slump and temperature values. In addition, the average cutter-head torque was reduced by about 250 kN·m. The amount of foaming agents used was reduced by about 18.6% and 12.9% on average in the two testing sites, respectively.]]></description>
      <pubDate>Tue, 09 Jan 2024 09:09:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310025</guid>
    </item>
    <item>
      <title>Investigation of the time-domain linear viscoelastic response of warm mix asphalt mixture via discrete and continuous spectrum</title>
      <link>https://trid.trb.org/View/2210684</link>
      <description><![CDATA[Asphalt mixture is a temperature-sensitive material, and its viscoelastic properties are essential for pavement design and performance evaluation. This paper presents a method for investigating the time domain linear viscoelastic parameter response of asphalt mixture after adding different warm mix agents. The approach utilizes the generalized Sigmoidal function to construct master curves of storage modulus and loss modulus in the frequency domain, and both discrete and continuous spectrum analyses are used to analyze the viscoelastic behavior of the asphalt mixture. The effects of varying Kelvin and Maxwell element numbers on the discrete spectrum are compared to the spectral intensity and master curve obtained from the continuous spectrum. Results show that the generalized Maxwell model with 10−3 or 10−2 as the center point and the generalized Kelvin model with 103 or 104 can obtain more accurate results. When used as input for simulation software, the number of 11 elements can balance computational efficiency and accuracy. The study evaluates the impact of different warm mix agents on the relaxation modulus and creep compliance of asphalt mixture and discusses the practical implications of these findings for engineering applications. Adding Foam warm mix agent significantly lowers the asphalt mixture's relaxation modulus by approximately 44%, while Sasobit and Evotherm marginally raise it by 14% and 22%, respectively. The Foam warm mix agent also increases the equilibrium modulus of creep compliance to 0.091 MPa, 80% higher than that of HMA. The findings of this paper provide guidance for selecting the appropriate warm mix agent to improve pavement performance.]]></description>
      <pubDate>Wed, 26 Jul 2023 15:59:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2210684</guid>
    </item>
    <item>
      <title>Rejuvenating aged asphalt using surfactant-foaming warm recycling technology</title>
      <link>https://trid.trb.org/View/2161726</link>
      <description><![CDATA[Warm mix recycling technology can accommodate higher content of reclaimed asphalt pavement (RAP) material, contributing to environmental benefits. However, it is still unsure which warm mix technology works best with the RAP. In this study, a combination of the foaming process and surfactant additive was used to recycle aged asphalt. By applying a series of rheological and chemical tests, the performance of regenerated aged asphalt using surface-activated foaming technology was evaluated. Besides, the regeneration effect was compared with that of bio rejuvenator and soft asphalt. It was found that the surfactant could recover the aged asphalt to a certain extent, but it was still difficult to recover it to the original level. The content of the aged binder had a great influence on the performance of recycled asphalt. When the content of aged asphalt was less than 50%, the softening and viscosity reduction effect of foamed Evotherm DAT was the best, and Evotherm DAT and soft asphalt were superior to bio rejuvenators in improving fatigue performance. The micro characteristic indexes such as sulfoxide index, GPC parameters, and bee-shaped area ratio can effectively explain the changes in engineering properties of asphalt binder in aging and regeneration.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2161726</guid>
    </item>
    <item>
      <title>Effects of diluted methanol and water as foaming agents on the performance of latex foamed warm asphalt mixtures</title>
      <link>https://trid.trb.org/View/2193011</link>
      <description><![CDATA[Latex as an asphalt modifier has gained popularity in the asphalt industry as it improves the durability of asphalt pavement. However, the elastomeric properties of latex stiffen the asphalt binders, resulting in additional energy consumption during the production of asphalt mixtures, which may cause a higher emission of greenhouse gases. This is undesirable for sustainable development and the environment. In this study, the applicability of diluted methanol and water was comparatively evaluated as foaming agents in the production of warm mix asphalt (WMA) mixtures incorporating latex. Diluted methanol was used because it has a lower boiling point and latent heat than water, allowing the asphalt mixture to be produced at a lower temperature and thus consuming less energy. The performance of the foamed asphalt mixture was investigated through service characteristics, mechanical performance, and moisture susceptibility of mixtures. The service characteristics, on the other hand, were measured in a laboratory while preparing and compacting the asphalt mixture, which refers to the amount of energy required during the production and construction stages in the asphalt plant and on the construction site, respectively. The degree of energy required was assessed based on the workability index, coatability index, and the compaction energy index. The mechanical performance of asphalt mixtures was characterized by indirect tensile strength, resilient modulus, and dynamic creep tests. The resistance to moisture damage was evaluated based on the common parameter, indirect tensile strength ratio. The findings revealed that the use of diluted methanol foaming agent helped improve the workability of latex modified asphalt mixtures. The foamed latex-modified WMA demonstrated better performance compared to asphalt mixtures prepared using water as the foaming agent.]]></description>
      <pubDate>Tue, 20 Jun 2023 10:09:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2193011</guid>
    </item>
    <item>
      <title>Novel Methods for Adding Rejuvenators in Asphalt Mixtures with High Recycled Binder Ratios</title>
      <link>https://trid.trb.org/View/2008566</link>
      <description><![CDATA[The overall objective of this study was to explore three novel rejuvenator application methods using the emulsion and foaming technologies and determine their impacts on the workability and long-term cracking resistance of high-reclaimed asphalt pavement (RAP) asphalt mixtures. To that end, a comprehensive experimental plan was developed, which consisted of four supplementary experiments focusing on rejuvenator characterization, foaming measurements of rejuvenators and rejuvenated asphalt binders, RAP pretreatment and marination evaluations, and mixture performance testing, respectively. Test results indicated that adding rejuvenators for RAP pretreatment improved the overall quality characteristics of RAP. Among the three rejuvenator application methods evaluated for RAP pretreatment, the emulsion method was found more effective than the spray-on and foaming methods. Marinating the pretreated RAP had a notable impact on the rheological and chemical properties of the extracted RAP binders, but it did not significantly affect the workability, appearance, and color consistency of RAP. Adding rejuvenators, in general, improved the workability and cracking resistance of high-RAP mixtures, although the improvement in mixture performance test results, in some cases, was not statistically significant. Among the different rejuvenator application methods, pre-blending the rejuvenator into the virgin binder (with or without foaming) provided slightly better or equivalent rejuvenating effectiveness and thus, mixture performance properties, than adding the rejuvenator for RAP pretreatment. Based on the findings of the study, it was recommended that asphalt contractors continue to use the pre-blending method of adding rejuvenators for the design and production of high-RAP mixtures due to performance and ease of operation considerations.]]></description>
      <pubDate>Mon, 29 Aug 2022 09:27:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2008566</guid>
    </item>
    <item>
      <title>A Guide for Methods to Transition and Decontaminate PFAS from Firefighting Systems</title>
      <link>https://trid.trb.org/View/2004700</link>
      <description><![CDATA[The Federal Aviation Administration (FAA) requires U.S. airports to utilize aqueous film-forming foam (AFFF), which contains per- and polyfluoroalkyl substances (PFAS). As airports prepare to transition away from these legacy foams because of environmental risk factors, it is imperative that existing fire-suppression equipment, aircraft rescue and firefighting (ARFF) vehicles, and hangar foam-suppression systems be decontaminated prior to the use of fluorine free foam (F3). Airports should consider effective and efficient methodologies for the best approach of decontamination. The objective of this research is to develop a guide for U.S. airport sponsors and stakeholders that have the responsibility of transitioning from using AFFF to F3, including decontaminating PFAS from firefighting vehicles and equipment, and hangar fire-suppression systems. This project was terminated. ]]></description>
      <pubDate>Tue, 09 Aug 2022 13:30:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2004700</guid>
    </item>
    <item>
      <title>Application of diluted methanol to allow the production of latex modified asphalt mixture with lower energy consumption</title>
      <link>https://trid.trb.org/View/1718578</link>
      <description><![CDATA[The modification of asphalt mixtures using latex has gained popularity in the asphalt industry as it improves the durability of road pavement. However, the elastomeric properties of latex stiffen the binder, resulting in more energy consumption during the asphalt mixture production. It would consequently cause a higher emission of greenhouse gases, which is undesirable for the human health and environment. This study aims to assess the applicability of diluted methanol as a foaming agent in asphalt mixture incorporating latex produced at a lower temperature. In this study, two designated amounts of diluted methanol (1% and 3% of the weight of asphalt binder) were successively injected with 6% latex into pre-heated asphalt binder at 135 °C in the preparation of foamed binders, while the control and latex modified asphalt mixtures were prepared at 160 °C. Tests of rotational viscosity, expansion rate, and torsional recovery were conducted to study the rheological properties of the mixtures. Service characteristics were evaluated through the indices of workability, compaction energy, and coatability. Moreover, mixture performance tests were carried out to identify the tolerance of the mixtures towards moisture damage, shear force, and permanent deformation. Through the rotational viscosity test, diluted methanol was found to reduce the viscosity of the asphalt binders, which is vital in the production processes at intermediate temperatures. The enhancement in viscosity using 3% diluted methanol had facilitated in higher workability, lower compaction energy, and better aggregate coating, which are the crucial criteria for a better mixing and compaction process. Whereby, a superior foaming quality was exhibited from the 3% diluted methanol application through the assessments of expansion ratio, half-life and foaming index. The moisture and shear resistances of the diluted methanol foamed asphalt mixtures are comparable to the control mixtures even though they were prepared at a lower temperature. Finally, the 3% diluted methanol foamed asphalt mixture promoted a better rutting resistance due to its ability to recover to the initial form which was demonstrated through its torsional recovery.]]></description>
      <pubDate>Thu, 23 Jul 2020 16:16:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1718578</guid>
    </item>
    <item>
      <title>Comparative Study of Ethanol Foamed Asphalt Binders and Mixtures Prepared via Manual Injection and Laboratory Foaming Device</title>
      <link>https://trid.trb.org/View/1601991</link>
      <description><![CDATA[The consistency of the ethanol foamed binders and mixtures prepared using asphalt binders foamed by the manual injection technique and laboratory foaming device were evaluated and compared in this study. The asphalt binders foamed using both methods was prepared at 120 °C, 130 °C and 140 °C. The performance of ethanol-foamed binders was evaluated in terms of rotational viscosity, expansion ratio, and low temperature cracking. Meanwhile, the performance of foamed WMA mixtures was tested using semi-circular bending (SCB), disk-shaped compact tension (DCT), and tensile strength ratio (TSR) tests. In order to conduct the TSR test, the samples were conditioned using the Moisture Induced Stress Tester (MIST) to simulate the pore pressure and scouring effects due to a tire passing over wet pavement. The foamed WMA mixtures were produced using pre-heated aggregates at 80 °C and 100 °C and foamed asphalt binders produced at 130 °C. The nano-hydrated lime was used as the filler and anti-stripping agent. Overall, the properties of ethanol-foamed binders and WMA mixtures produced via both methods are significantly comparable, except the resistance to moisture damage test result. However, the findings indicate that the ethanol-foamed WMA mixtures prepared using both techniques are having good resistance to moisture damage, based on the TSR values more than 0.8. The foamed WMA mixtures also exhibited a better resistance to cracking, as indicated by a higher tensile strength compared to the control HMA. Additionally, the WMA specimen prepared at 100 °C was less susceptible to rutting than the samples produced at 80 °C.]]></description>
      <pubDate>Mon, 29 Apr 2019 09:26:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1601991</guid>
    </item>
    <item>
      <title>Characterizations of Foamed Asphalt Binders Prepared using Combinations of Physical and Chemical Foaming Agents</title>
      <link>https://trid.trb.org/View/1582662</link>
      <description><![CDATA[The objective of this study is to characterize the foamed asphalt binders prepared using different combinations of physical and chemical foaming agents. The foamed asphalt binders were investigated using the Rotational Viscosity (RV), Dynamic Shear Rheometer (DSR) and expansion ratio tests. Asphalt binders were also evaluated after short-term and long-term aging conditions. During the asphalt binder’s foaming process, the preheated binder was formerly foamed using a physical foaming agent (either water or ethanol), followed by the addition of sodium bicarbonate (NaHCO3) to improve the bubbling and the stability of the foam. Theoretically, through this process, numerous bubbles are generated by the vaporized ethanol or water, and the gases are released by NaHCO3, which significantly increases the volume of foamed asphalt. All foamed asphalt binders were produced at the same temperature, 100 °C, to diminish the inconsistency of binder-aging conditions during the preheating process. Overall, the results indicated that ethanol has better characteristics in lowering the viscosity of asphalt binders at low temperatures and is expelled from the asphalt binder after continuous heating at temperatures higher than its boiling point (78 °C). Although the addition of NaHCO₃ has slightly increased the foamed binder viscosity that may affect its workability, it substantially lowers the volatile loss of foamed binders, as well as significantly improves the expansion ratio and the resistance to rutting.]]></description>
      <pubDate>Fri, 29 Mar 2019 10:20:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1582662</guid>
    </item>
    <item>
      <title>Influence of Foaming Water and Aging Process on the Properties of Foamed Asphalt</title>
      <link>https://trid.trb.org/View/1541801</link>
      <description><![CDATA[Foamed asphalt is a good technique to reduce energy consumption and protect environment by decreasing the construction temperature of asphalt mixture. Many efforts have focused on the original foamed asphalt such as foaming characteristics and rheological properties, but how the performance of samples at different aging stages changing has been few studied. Therefore, foamed asphalts sampales with different foaming water (0wt%, 1.0wt%, 2.0wt% and 3.0wt%) at three stages (unaged, short-term aging and long-term aging) are investigated in this study. The high-temperature performance, low-temperature performance, temperature susceptibility, fatigue performance and microstructure of foamed asphalt were evaluated by Brookfield viscosity tests, dynamic shear rheology (DSR) tests, bending beam rheometer (BBR) tests and Fourier Transform Infrared spectroscopy (FTIR) tests. The results show that the foaming water content and aging process have great influence on the rheological properties and microstructure of non-foamed and foamed asphalt. Foaming water decreases the failure temperature, ZSV@60°C, low temperature performance, and fatigue resistance while it could improve temperature sensitivity. Aging process has better for viscosity, rutting resistance factors and temperature sensitivity of non-foamed and foamed asphalt. Meanwhile, less foaming water has better effect on the anti-aging properties of asphalt.]]></description>
      <pubDate>Thu, 18 Oct 2018 10:14:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1541801</guid>
    </item>
    <item>
      <title>Mesoporous Silica Material MCM-41: Novel Additive for Warm Mix Asphalts</title>
      <link>https://trid.trb.org/View/1523873</link>
      <description><![CDATA[This study evaluates the impact of a new generation additive MCM-41 saturated with water on the asphalt foaming. MCM-41 is a mesoporous silica material which is produced in the process of synthesis from the fly ash. Experimental design included the assessment of reference asphalt specimens as well as asphalt specimens prepared with addition of MCM-41 material from 1.5 to 4 wt%. The mesoporous silica material used in this research featured a high specific surface area and a mesopores volume of 1134 m2/g and 0.980 cm3/g, respectively. The assessment of asphalt specimens was performed in terms of dynamic viscosity as a function of time (measured after 30 and 45 min of mixing) and temperature (135 °C and 160 °C). The most significant decrease in viscosity was observed for asphalt specimens prepared with 3 wt% concentration of MCM-41 material. The results presented in this paper suggest that MCM-41 mesoporous silica material can be more effective additive to warm mix asphalts (WMA) when compared to other currently used agents (zeolites, waxes, etc.). Concurrently, synthesis of MCM-41material based on the waste materials such as fly ash is environmentally friendly and economically feasible. These results have initiated another research project which includes a comprehensive mechanical and chemical assessment of different asphalts modified with MCM-41 additive and mechanical evaluation of corresponding WMA to investigate the optimal MCM-41 content.]]></description>
      <pubDate>Mon, 27 Aug 2018 14:06:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1523873</guid>
    </item>
    <item>
      <title>Effect of Mixing Speed on Rheology of Superplasticized Portland Cement and Limestone Powder Pastes</title>
      <link>https://trid.trb.org/View/1475187</link>
      <description><![CDATA[This paper examines the effect of mixing intensity on superplasticized cement pastes and reference limestone pastes; specifically, the effects of high mixing intensity on the rheological properties were examined. Increasing the mixing intensity applied to a paste does not always cause a reduction in the rheological properties of the paste, especially when the pastes contain a high-range waterreducing admixture (HRWRA). Mechanisms underlying this effect were examined. The physical effects due to cement being a powder material cannot solely explain the behavior seen; rather, the chemical effects from cement being hydraulic, as well as the amount of foaming of the incorporated admixture, play a role. Pastes prepared with an HRWRA that had a high degree of foaming exhibited greater increases in their rheological response than pastes prepared with HRWRAs containing low foaming potential, which suggests that the air bubbles in the foam network act as rigid inclusions instead of soft, deformable inclusions.]]></description>
      <pubDate>Thu, 27 Jul 2017 10:05:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1475187</guid>
    </item>
  </channel>
</rss>