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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>
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      <title>Transport Research International Documentation (TRID)</title>
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    <item>
      <title>Comparative evaluation of mechanical degradation of asphalt mortars and mixtures caused by solution erosion and the underlying mechanism</title>
      <link>https://trid.trb.org/View/2630939</link>
      <description><![CDATA[To investigate the evolution of the mechanical properties and the underlying degradation mechanisms of asphalt mortars and mixtures, this study combines macroscopic indirect tensile (IDT) tests, nanoscale molecular dynamics (MD) simulations, and a supplementary back-propagation (BP) neural network model. Results reveal a distinct scale effect where mastic hardening is more influential in mortars while interfacial weakening governs mixture performance, a process effectively mitigated by the inclusion of a modifier. In the context of this complex damage, the comprehensive secant modulus (Sbp) is established as a more robust evaluation index than other traditional single-stage indexes. The BP neural network model details that the complex performance degradation is obscured by a competing aging effect from its virgin asphalt mastic. MD simulations reveal the nanoscopic origin of this behavior, identifying that the presence of water and ions strengthens the asphalt mastic’s interaction energies, a phenomenon driven by the formation of potent hydrogen-bond and ion-dipole networks that fundamentally restructure the mastic system. Further, the long-term immersion degradation of asphalt mastic is a synergistic process governed by a thickening water film, which disrupts adhesion and creates a corrosive environment. This environment drives a dual degradation mechanism during long-term immersion: it physically disrupts interfacial adhesion while promoting the electrostatic-driven dismantling of the asphaltenic network and resin phase. This process ultimately transforms the material’s colloidal structure into a destabilized, multi-phase entity responsible for macroscopic deterioration. The study mechanistically links the mechanical degradation of asphalt mortar and mixture under solution erosion to the nanoscopic, electrostatic-driven restructuring of their mastic’s colloidal structure.]]></description>
      <pubDate>Mon, 22 Dec 2025 17:03:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2630939</guid>
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    <item>
      <title>Study on the road performance and development mechanism of polyurethane binder in different media solutions</title>
      <link>https://trid.trb.org/View/2603305</link>
      <description><![CDATA[Polyurethane pavements are significantly impacted by complex water environments, including acid rain, road alkalization, engine oil, and de-icing salts. This study quantified the performance loss and elucidated the degradation mechanisms of polyurethane binder under these solutions conditions. The solution soaking tests simulating environmental exposure were conducted, followed by characterization of surface morphology, mechanical properties, thermal stability and other performances. The degradation mechanisms were further elucidated through microstructure, hydrogen bonding, and crosslinking density. Finally, polyurethane binder's adaptability to road environments was comprehensively evaluated by the radar chart-based composite suitability index. The results indicated that exposure to acid, alkali, oil, salt, and water solutions reduced the polyurethane binder's toughness by 15.8 %-28.1 % and caused visible surface alterations attributed to chemical changes. The water solution has been proven to reduce the polyurethane binder’s macroscopic properties by weakening hydrogen bonds and cross-linking density. Acidic and alkaline solutions could accelerate hydrolysis of the polyurethane binder, reducing cross-linking chain proportion by 5.4 %-8.4 %. Chloride ions in salt solution deteriorated properties by breaking chemical bonds, reducing crosslinking density by 5.1 %. The oil solution degradation to polyurethane binder primarily resulted from swelling effects. Overall, the deteriorating severity of water, alkali, oil, acid, and salt solutions on polyurethane binder intensify sequentially. The research findings hold significant implications for assessing the environmental adaptability of polyurethane pavements.]]></description>
      <pubDate>Thu, 13 Nov 2025 09:28:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2603305</guid>
    </item>
    <item>
      <title>Microscopical properties of asphalt mastic under solution erosion and its deterioration mechanism</title>
      <link>https://trid.trb.org/View/2563335</link>
      <description><![CDATA[To investigate the evolutionary characteristics of solution erosion on asphalt mastic microstructures and reveal the degradation mechanisms of surface properties, three immersion environments, namely, pure water, salt, and alkali solutions, were considered. Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were performed on the virgin and styrene-butadiene-styrene (SBS) modified asphalt mastic to systematically characterize the evolution of the chemical composition, surface structure, and morphology of the asphalt mastic. The results demonstrated that solution erosion induced wateroxygen aging in asphalt mastics, with concomitant degradation of SBS modifier molecular structures. Salt precipitation has been observed in salt environments, whereas alkali conditions triggered neutralization reactions that increased the solution’s oxygen-carrying capacity, ultimately leading to macroscopic hardening. Notably, exploratory findings were that well-developed bee structures on virgin and SBS asphalt mastic surfaces underwent phase degradation post-immersion, resulting in spindle-shaped pits, marginal ablation, and fractured fragments. In particular, after long-term immersion, virgin mastics displayed wax crystal reassociation and extensive crosslinking wrinkles, whereas their SBS-modified counterparts predominantly exhibited flaky cracks and insufficient gel nuclei regeneration. Among them, the surface deterioration of the mastic after alkali solution was the most severe, as shown by the wrinkled network of virgin material and the clustering of pits and grooves in the SBS mastic. It is worth mentioning that the strong correlation shown between the deterioration indexes (DIs) indicates the rational significance of the experimental protocol of this research. Overall, solution erosion caused depolymerization of the molecular structure of SBS modifiers, whereas the influence of salt and the neutralization of alkali solutions further exacerbated the microstructural deterioration of the mastic, which was even more dramatically affected by immersion days. Moreover, the alkali solution outperformed the salt solution in terms of the decrease in bee like structural and roughness parameters of the asphalt mastic. These findings emphasize and analyze the solution-specific degradation mechanisms as critical factors in asphalt mastic durability for sustainable pavements.]]></description>
      <pubDate>Wed, 23 Jul 2025 09:14:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2563335</guid>
    </item>
    <item>
      <title>Effect of aqueous solution exposure on the long-term aging performance of asphalt</title>
      <link>https://trid.trb.org/View/2487204</link>
      <description><![CDATA[Asphalt pavements are easily exposed to moisture during service. Changes in the properties of asphalt binders during aging may be affected by their solution exposure history. The impact of solution exposure experienced by asphalt in the early stages of service on the long-term aging performance was investigated using three aqueous solutions, including acidic, saline, and alkaline solutions. The surface morphology of the asphalt specimens after solution exposure was recorded and analyzed, while Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Shear Rheometer (DSR), and contact angle test were applied to investigate the effects of solution exposure on the chemical functional groups, rheological properties, and cohesion properties of asphalt after long-term aging. The results showed that the surface roughness of asphalt specimens increased significantly when the solution exposure intensity reached a certain level. Meanwhile, solution exposure not only increased the oxidative aging of asphalt in the short term, but also led to higher degrees of oxidation during long-term aging. In addition, compared with the control group, solution-exposed asphalt was softer and more viscous at high temperatures and more elastic at mid-temperatures after aging, resulting in worse rutting resistance yet slightly better fatigue properties. Furthermore, solution exposure amplified the reduction in surface free energy of the asphalt after aging, and hence the cohesion property became worse.]]></description>
      <pubDate>Thu, 20 Feb 2025 16:25:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2487204</guid>
    </item>
    <item>
      <title>Comprehensive properties assessment of asphalt binder under aqueous solutions with different pH values and its gradient damage behaviors</title>
      <link>https://trid.trb.org/View/2326931</link>
      <description><![CDATA[This study characterized the morphology, high-temperature property, rheological property, adhesion, cohesion, and chemical component of asphalt binder under aqueous solutions of different pH values. Then the physicochemical properties of asphalt binder were comprehensively evaluated by the improved radar chart. The properties of asphalt binder stripped layer-by-layer were explored to elucidate its gradient damage behaviors. The results indicate that the pH 3 solution reveals the greatest impact on the morphology of 90 asphalt (90 A) and styrene-butadiene-styrene modified asphalt (SBS MA), leading to the wide cracks on 90 A and the network cracks on SBS MA. The comprehensive assessment index of 90 A exposed to pH 3, pH 5, pH 7, pH 9, and pH 11 solutions can be reduced by 20.8%, 20.2%, 1.5%, 14.0%, and 25.5%, respectively. While for SBS MA, its corresponding values variation are 23.2%, 17.7%, 4.6%, 8.7%, and 13.0%, respectively. The acid solutions significantly affect the comprehensive properties of 90 A, but their pH value has little effect. 90 A exposure to the higher pH value of alkali solution reveals the worse comprehensive properties. Acid solute and alkali solute can aggravate the effect of aqueous solution on the comprehensive properties of SBS MA, and the degree of aggravation increases with the increase of solute concentration. The properties of asphalt binders exhibit varied gradient damage behaviors under different solute environments. The most serious damage occurs at 25–50 µm of 90 A and 0–50 µm of SBS MA. This study facilitates an accurate understanding of the mechanism of pavement distresses and composition design and construction utilization of asphalt binders.]]></description>
      <pubDate>Wed, 28 Feb 2024 13:58:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2326931</guid>
    </item>
    <item>
      <title>Dramatic Emissions Reductions with a Direct Injection Diesel Engine Burning Supercritical Fuel/Water Mixtures</title>
      <link>https://trid.trb.org/View/1791616</link>
      <description><![CDATA[Research conducted at the Supercritical (SC) facility of MIT's Energy Laboratory provided visual confirmation of a single phase, homogeneous water/fuel mixture near the critical temperature and pressure of water. Equal volumes of water and diesel fuel were observed to be completely miscible, and high temperature polymerization of fuel molecules was not found. This is believed to be the first observation of a solution of diesel fuel and water. This mixture was subsequently burned under atmospheric spray conditions with very low NOₓ, smoke, CO, and HC. The results suggested that in-cylinder combustion in a compression ignition engine was warranted. Tests were conducted in a single cylinder, air-cooled, naturally aspirated, 3.5 horsepower Yanmar diesel engine. The compressibility of this new fuel composition necessitated a modified injector to provide smooth operation. An electronically controlled, common rail injection system was developed using modified injectors to operate at temperatures above 350°C in the presence of water. Early results comparing injection and combustion of this fuel/water solution with standard diesel operation were uniformly positive. An 85% decrease in NOₓ and a virtual elimination of smoke was measured on an AVL smoke meter. Noise levels were reduced by 2.7dB. Efforts are continuing with larger engines and injection optimization.]]></description>
      <pubDate>Tue, 05 Dec 2023 10:31:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1791616</guid>
    </item>
    <item>
      <title>The effect of water solution erosion on rheological, cohesion and adhesion properties of asphalt</title>
      <link>https://trid.trb.org/View/1688892</link>
      <description><![CDATA[Asphalt pavement will be damaged under the action of asphalt aging and moisture damage. Water solution erosion degree is closely related to the aging of asphalt and degradation of the adhesive strength between asphalt and aggregate. In view of this, this paper investigated the effect of water solution erosion on rheological, cohesion and adhesion properties of virgin and aged asphalt. The experiment was performed by immersing asphalt into five different water solutions (includes distilled water, acid solution, alkali solution, sodium chloride solution and sodium sulfate solution) for different time, which was considered to be fully reflect the real service condition within an asphalt pavement in different areas. The rheological properties were evaluated by dynamic shear rheometer (DSR), the cohesion and adhesion properties based on the surface free energy test were got by sessile drop method. Meanwhile, the relationships between asphalt rheological, cohesion and adhesion properties with aqueous solute and water solution erosion time were studied. The effects of water solution erosion on virgin asphalt and its PAV aged asphalt were compared. It was observed that water solution erosion resulted in the increased of asphalt elastic component and stiffness, decreased of asphalt fatigue life and the cohesive force and adhesion to aggregates. This trend was reduced to some extent with the presence of acid, alkali, and salt solutes. Under the action of water solution erosion, PAV aged asphalt showed a worse resistance to water solution erosion. And unlike heat-aging and ultraviolet-aging, the development trends of rheological, cohesion and adhesion properties of asphalt were more complex and variable with the change of asphalt surface component.]]></description>
      <pubDate>Fri, 27 Mar 2020 15:03:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1688892</guid>
    </item>
    <item>
      <title>Tire–Pavement Interaction in Contact with Salted Snow: How an Aqueous Solution Affects Compression, Squeeze-Out, and Compaction of Snow</title>
      <link>https://trid.trb.org/View/1679465</link>
      <description><![CDATA[During winter, large amounts of salt are used on roads to keep them safe for vehicular traffic. However, applying high levels of salt is harmful to the environment, vehicles, and infrastructure. In order to optimize the amount of salt used on roads without compromising traffic safety, it is useful to increase the knowledge about how salt affects snow properties. This study investigates the effects of salt solution on snow when a tire rolls over it. An indoor test experiment was developed to study the compression, compaction, and squeeze-out mechanisms of salted snow. Dendritic artificial snow was mixed with different amounts of salt solution from 0 to 40% by weight. The main findings of this study are that snow containing a salt solution compresses to a higher density; more snow gets squeezed out of the contact area compared to fresh snow. The snow that becomes compacted under the weight of tires is weaker when a salt solution is present. These effects take place using relatively small amounts of salt solution (10% by weight). These results can be used to optimize salt applications rates during a snowfall, an assertion that is discussed in this paper.]]></description>
      <pubDate>Fri, 20 Mar 2020 10:12:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1679465</guid>
    </item>
    <item>
      <title>Simulation and Optimization of Road Deicing Salt Usage based on Water-Ice-Salt Model</title>
      <link>https://trid.trb.org/View/1659811</link>
      <description><![CDATA[This study aims at helping optimize the application and usage of deicing salts on the winter road surface. Laboratory experiments were conducted for observing how volume and temperature of salt solution change during the deicing process as well as for calculating the dissolution rates of salt. Additionally, a time-dependent model for the prediction of salt solution temperature on a road surface was developed, which takes into account the effects of salting and ambient environment. Its validity was examined through experiment. Based on the experiment results, the relationship between the temperature of deicing salt solution and its freezing point was formulated, a method was therefore developed to predict the amount of salt applied on frozen road, which takes air temperature, wind speed and ice thickness into account. This salt amount prediction method can effectively optimize the usage of road deicing salt bestrewed on winter frozen road, which was verified by experiment.]]></description>
      <pubDate>Thu, 14 Nov 2019 09:32:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1659811</guid>
    </item>
    <item>
      <title>Experimental Analysis of SCR Spray Evolution and Sizing in High-Temperature and Flash Boiling Conditions</title>
      <link>https://trid.trb.org/View/1638231</link>
      <description><![CDATA[

In the last years, new stringent emission legislation in terms of nitrogen oxides (NOx) has been leading to a massive development of advanced after-treatment systems for diesel engines. Among them, selective catalytic reduction (SCR) technology has proved to be an effective approach for NOx reduction in a wide range of engine operating conditions. In SCR systems, the interaction between diesel exhaust fluid (DEF) and hot exhaust gas is crucial to promote the chemical reactions through which ammonia is produced. Hence, a proper matching between the exhaust pipe architecture and the DEF spray is mandatory for obtaining an adequate SCR efficiency, especially in close-coupled configurations and moderate exhaust gas temperature conditions. To this end, significant benefits could be derived via appropriate SCR injector thermal management, as the spray structure is significantly influenced by the DEF temperature upstream of the injector nozzle.
In this article, the results of a spray analysis campaign carried out on a prototype DEF dosing system are presented. The goal of this research is to investigate the influence of both air and DEF temperature upon spray structure and atomization. In a previous investigation, preliminary tests were carried out using a hot flow bench (HFB) in order to perform spray evolution and SCR system efficiency analyses in realistic flow rate and temperature conditions. In the current investigation, a deeper analysis was carried out individually controlling DEF and test vessel air temperature, with the spray evolving in quiescent hot conditions. Mie scattering and Schlieren spray images were simultaneously acquired in order to investigate both liquid and vapor spray phase evolution, in order to perform a characterization of spray global structure. In the same conditions, a dedicated test campaign was carried out to perform drop sizing analysis. Some of the most significant results are discussed, along with their possible effects in real exhaust system applications.
]]></description>
      <pubDate>Tue, 01 Oct 2019 11:27:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1638231</guid>
    </item>
    <item>
      <title>Evaluation of Dissolved Organic Carbon Released from Aged Asphalt Binder in Aqueous Solution</title>
      <link>https://trid.trb.org/View/1628447</link>
      <description><![CDATA[Asphalt binder which is usually used in pavement construction, is a kind of organic material. Dissolved organic carbon (DOC) will be released from asphalt by rainfall wash and runoff, resulting in potentially environment influence by transferring such hazardous matters into aqueous and soil system. By simulating the aging process of asphalt binder in laboratory, this work presented the results of a study addressing release of DOC from different aged asphalt binders. Leaching behavior, characteristics of aged asphalt after leaching, chemical composition and carbon speciation of leachates were discussed. Leachability and factors were analyzed by grey relation theory method. The concentration of DOC ranged from 3.95 mg/L to 23.6 mg/L for all leachates. Aging enhanced the leachability of DOC released from asphalt. Combined with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) analysis indicated that the polar matters containing hydroxyl and carbonyl group increased by aging treatment and then enhanced the leachability of DOC from aged asphalt. Meanwhile, a significant increase and decrease of oxygen content was obtained for asphalt binders respectively after aging and leaching. As a result, the organic matters in leachates significantly increased and mainly consisted of hydrocarbons and oxygen containing compounds. The proportion of fulvic acids (FA) and hydrophilic organic carbon (Hy) fraction was dominate while a small percentage of humic acids (HA) was obtained. Grey incidence analysis showed absolute grey index (AGI) value varied from 0.5107 to 0.7064, which indicated that DOC leaching was likely pH-dependent for thin film oven test (TFOT) and ultraviolet (UV) aged asphalt while time was main influential factor for pressure aging vessel (PAV) aged asphalt.]]></description>
      <pubDate>Wed, 21 Aug 2019 09:35:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1628447</guid>
    </item>
    <item>
      <title>Analytical Modeling for Solute Transport in a Homogeneous Medium</title>
      <link>https://trid.trb.org/View/1588511</link>
      <description><![CDATA[In the present scenario, developing countries are experiencing a rapid growth due to urbanization. Many of the watersheds of India are facing water quality issues caused by anthropogenic sources like high industrialization, population growth, and urbanization. Fluid flow and solute transport to the subsurface environment are the most detrimental activities in the urbanized area and it is one of the biggest challenge facing watershed managers. As it is very difficult to eliminate the source activities permanently, a thorough understanding of flow processes combined with transport mechanisms is required in order to minimize such water quality hazard. This study seeks an interaction of principal transport mechanisms like advection and dispersion and its effect on solute movement. To solve and analyze these problems, an analytical scheme is used which is based on a mathematical combination of the variational iteration method and the homotopy perturbation method. Sensitivity analysis is carried out with changing transport parameters like velocity and dispersion of the media and concentration profiles are studied using the analytical model. It has found that the potential of solute concentration is more with the high flow velocity and however conversely varies with respect to the dispersion of the porous medium.]]></description>
      <pubDate>Mon, 01 Apr 2019 10:15:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1588511</guid>
    </item>
    <item>
      <title>Effects of Reflux Temperature and Molarity of Acidic Solution on Chemical Functionalization of Helical Carbon Nanotubes</title>
      <link>https://trid.trb.org/View/1560239</link>
      <description><![CDATA[The use of nanomaterials and nanostructures have been revolutionizing the advancements of science and technology in various engineering and medical fields. As an example, Carbon Nanotubes (CNTs) have been extensively used for the improvement of mechanical, thermal, electrical, magnetic, and deteriorative properties of traditional composite materials for applications in high-performance structures. The exceptional materials properties of CNTs (i.e., mechanical, magnetic, thermal, and electrical) have introduced them as promising candidates for reinforcement of traditional composites. Most structural configurations of CNTs provide superior material properties; however, their geometrical shapes can deliver different features and characteristics. As one of the unique geometrical configurations, helical CNTs have a great potential for improvement of mechanical, thermal, and electrical properties of polymeric resin composites. The coil spring shape of these CNTs give them the capability to withstand high loads and considerable deformations that can be recovered, upon unloading. In addition, due to their helical shape, the entanglement of these CNTs with each other and the polymeric crosslinked molecular chains is much higher compared to the straight CNTs. Therefore, they can potentially absorb more impact loads and deliver higher resilience and flexibility in composites. One of the main issues for using these nanomaterials in composites is the uniform dispersion of these nanoparticles in the matrix system, besides their poor interface properties. This research reports a method for functionalization of helical CNTs (HCNTs) and investigates the effects of processing parameters, which can influence the effectiveness of the proposed chemical functionalization methods. The proposed method uses a refluxing process with a strong acidic solution; here, the effects of molarity and temperature, as two influential parameters, were investigated. For characterization of the functionalized helical CNTs, X-ray diffraction spectroscopy (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), visual dispersion inspection, and Scanning Electron Microscopy (SEM) methods were used. According to the results, all functionalization processes were successful in increasing the attachment of functional groups to the surface of helical CNTs that resulted in better dispersion of helical CNTs in DI water. The increase in molarity (M) of the acidic solution beyond 3M resulted a higher dispersion rate and a lower crystallinity. In the case of using a high-reflux temperature, helical CNTs which were processed with a 3M or 16M acids displayed a substantial increase in the solubility compared to the ones which were refluxed at a low temperature.]]></description>
      <pubDate>Mon, 26 Nov 2018 10:06:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1560239</guid>
    </item>
    <item>
      <title>Numerical and experimental investigation of evaporation and mixture uniformity of urea–water solution in selective catalytic reduction system</title>
      <link>https://trid.trb.org/View/1505912</link>
      <description><![CDATA[Selective catalytic reduction (SCR) technology for the control of NOₓ emissions has become an attractive option for marine diesel engine applications because of the International Maritime Organization (IMO) Tier III regulation. SCR systems are effective over a wide temperature range in reducing NOₓ emissions during rich and lean operations. This study investigated the evaporation and thermal decomposition processes of urea–water solution (UWS) in an SCR system both experimentally and via simulation. It was found that a wall film forms at the inlet and outlet of the mixer in the mixing pipe as a result of deposition or splashing after impingement of urea droplets. A model of the evaporation and thermal decomposition of UWS to form the wall film developed in this study and utilized in simulations. Although the conversion rate of NOₓ reduction presented in the simulation case was slightly higher than that obtained experimentally, the simulation results were in good agreement with the experimental results. The results prove that it is possible to effectively predict the actual NOₓ reduction rate of an SCR system via simulations.]]></description>
      <pubDate>Thu, 19 Apr 2018 10:02:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/1505912</guid>
    </item>
    <item>
      <title>Dispersed ultra-fine bottom ash blended mortar</title>
      <link>https://trid.trb.org/View/1495882</link>
      <description><![CDATA[Replacing Portland cement with alternative sources of coal bottom ash can help supplement fly ash supply, have substantial benefits to the environment, and enhance the physical and mechanical concrete properties. The effectiveness and reactivity of the supplemental bottom ash powder will, however, depend largely on the ash particle fineness and dispersion within the cement matrix. In this study, a raw sub-bituminous coal bottom ash was pulverized using a vibratory ball mill, dispersed in solution with a poly-carboxylate ether superplasticizer and homogenized with an ultrasonication treatment. The ultra-fine dispersed solution was then blended within a cement mortar mix to study the impacts on compressive strength activity, matrix microstructure, sedimentation, and rheological stability. Two different sonication energies and dispersed bottom ash solid:liquid solutions were studied. The results indicate that there is a significant increase in strength activity and a reduction in calcium hydroxide content in the mixes containing dispersed bottom-ash solution. ANOVA was then conducted using 190 data points from both the current experimental program and previously published studies empirically quantify the effects of fineness, cement replacement, sonication, bottom ash solution concentration, and age on strength activity. Overall, the sonicated pulverized bottom ash blended cement mortar yielded approximately 6 – 17% greater strength activity than the non-sonicated control cement mortar mix and 2-13% greater strength activity than the non-sonicated blended cement-bottom ash mortar mix.]]></description>
      <pubDate>Mon, 26 Mar 2018 09:18:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1495882</guid>
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