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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <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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      <link>https://trid.trb.org/</link>
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      <title>Performance characterization, reinforcement, and application of recycled concrete aggregates in cement concrete and asphalt mixture: A state-of-the-art review</title>
      <link>https://trid.trb.org/View/2652751</link>
      <description><![CDATA[Urbanization renewal leads to a significant generation of construction and demolition waste (C&DW), predominantly concrete waste. It has been widely used as a recycled concrete aggregate (RCA) in pavement to alleviate the shortage of natural aggregates. This study presents a comprehensive review of the processing technology, performance characterization, performance enhancement measures, and application of RCAs in pavement engineering. It indicates that RCAs possess distinctive characteristics, multiple interfaces, microcracks, low bulk density, high water absorption, and specific abrasion values, which restricts its high-quality utilization. Removing or strengthening wrapping mortar are effective measures for improving the physical and mechanical properties of RCAs. RCAs can replace natural aggregates in cement concrete pavement using reinforcement techniques essential for durability. In asphalt mixtures, RCAs can substitute up to 60% of the natural aggregate while maintaining acceptable pavement performance. Recommending early adoption of reinforcing techniques and optimization of grading and mix proportions in pavement engineering promotes RCA utilization, supporting C&DW treatment as a recycled aggregate and improving overall efficiency in the future.]]></description>
      <pubDate>Mon, 26 Jan 2026 08:41:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2652751</guid>
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    <item>
      <title>Characterization of multi-waste concrete incorporating recycled aggregate, asphalt, fly ash, and rubber waste: Structural and environmental assessment</title>
      <link>https://trid.trb.org/View/2641873</link>
      <description><![CDATA[This study investigates sustainable concrete formulations incorporating recycled concrete aggregate (RCA), reclaimed asphalt pavement (RAP), crumb rubber (RR), and fly ash (FA), aiming to reduce environmental impact while maintaining structural performance. Nine mixes were experimentally evaluated for key physical (density, water absorption, sorptivity, porosity, ultrasonic pulse velocity) and mechanical properties (compressive and flexural strength, elastic modulus, Poisson’s ratio). Based on these results, two reinforced concrete buildings (3- and 8-story) were modeled and analyzed using nonlinear static (pushover) analysis. Life cycle impact assessments were carried out with SimaPro and Ecoinvent to quantify the environmental footprint of each case. Due to varying mechanical behavior, structural sections were resized accordingly, leading to different material demands and environmental outcomes. While all modified concretes showed reduced compressive strength (up to −56% vs. control), some achieved flexural strength increases (+27%) and improved ductility. A mix with 50% RCA, 25% RAP, and 20% FA required only a 2% increase in section size but yielded an average 20% reduction across environmental categories. In contrast, concretes with 50% RCA, 50% RAP, and 10% RR demanded between 5 and 10% larger sections and resulted in a 10% increase in environmental impact. This integrative, multiscale approach (i.e. experimental material testing, structural performance modeling, and environmental assessment) offers a robust and novel framework for developing low-impact concretes suitable for seismic design. However, further full-scale validation and long-term durability studies are necessary to confirm these findings and facilitate real-world implementation.]]></description>
      <pubDate>Mon, 29 Dec 2025 09:37:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2641873</guid>
    </item>
    <item>
      <title>Multiphase carbonation engineering of RCA via CO₂-enriched cement slurry treatment: Mechanistic insights into carbonation efficiency and asphalt pavement performance enhancement</title>
      <link>https://trid.trb.org/View/2602675</link>
      <description><![CDATA[The growing demand for sustainable pavement materials necessitates innovative approaches to enhance recycled concrete aggregates (RCA), whose surface defects critically undermine asphalt bonding performance. Given its high porosity and loosely bound structure, calcium silicate hydrate (C-S-H) is identified as the primary factor undermining RCA performance and thus the key target of modification. This study proposes a CO₂-enriched cement slurry treatment under ambient conditions to engineer the RCA microstructure through controlled carbonation of C-S-H. The treatment integrates three mechanistic pathways: hydration-induced hardening of unhydrated cement phases, carbonation curing of setting slurry, and targeted carbonation of residual microstructural pores on the RCA surface. The multiscale validation combines microstructural characterization, macroscale experiments, and molecular dynamics simulations to elucidate the interfacial mechanisms, complemented by a life cycle assessment. Results confirm the high efficiency of this multiphase carbonation strategy, achieving a 13.37 % reduction in RCA water absorption, 1.62 MPa bond strength enhancement, and 40.33 % increased Marshall stability. Nanoscale characterization reveals calcium carbonate precipitation reducing average pore diameter. Molecular dynamics confirms the interfacial binding energy between asphalt and RCA increased by 24.65 % and 28.99 % under dry and wet conditions. The number of hydrogen bonds formed between water molecules and the RCA surface decreases by 151, indicating enhanced moisture resistance and a reduced potential for water migration at the interface. Environmental analysis based on life cycle assessment demonstrates a substantial reduction in global warming potential and particulate emissions. This efficient carbonation approach converts construction waste into high-performance pavement materials while maximizing environmental benefits.]]></description>
      <pubDate>Tue, 11 Nov 2025 09:23:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2602675</guid>
    </item>
    <item>
      <title>Chemical treatment-driven enhancement of recycled concrete aggregate-asphalt interfacial adhesion properties and multiscale characterization</title>
      <link>https://trid.trb.org/View/2590820</link>
      <description><![CDATA[Recycled Concrete Aggregate (RCA) for asphalt pavement has the advantages of material saving, carbon and cost reduction. RCA has a special surface microstructure and chemical composition compared with natural aggregate, which leads to the particularity of interfacial adhesion between RCA and asphalt. Enhancing the surface properties of RCA is an important way to improve the road performance of asphalt mixtures containing RCA (HMA-RCA). Organic silicone resin and silane coupling agents are used to strengthen RCA. The effects of silicone resin type, coupling agent type, and curing temperature on the micromorphology and microadhesion function of RCA, as well as the water stability of HMA-RCA, were investigated. The results show that the adhesion force and surface energy of SJ-1850–2 samples increased gradually with rising curing temperature, whereas those of SJ-509N and SJ-528N decreased gradually. However, the adhesion and surface energy of the soaked samples with different varieties of silane coupling agents showed a tendency to increase and then decrease with increasing temperature. The surface energy of the KH560-soaked sample, with a curing temperature of 150 °C, was 110.90 mJ/m². The Sa and Sq of the SJ-1850–2 sample increased with increasing curing temperature, whereas the Sa and Sq of the SJ-509N and SJ-528N samples gradually decreased. The height parameters Sa, Sq, and Sz of the samples impregnated with different types of silane coupling agents basically showed a tendency to increase and then decrease with increasing curing temperature. The height parameters Sa, Sq, and Sz of different varieties of silane coupling agent-immersed samples showed a tendency to increase first and then decrease with the increase in curing temperature. Compared to unreinforced RCA, the MS0 and TSR of HMA-RCA treated with spraying SJ-528N improved by 6.2 % and 9.7 %, respectively; the MS0 and TSR of silane coupling agent-treated HMA-RCA were increased by 4.6 % and 5.0 %, respectively.]]></description>
      <pubDate>Thu, 16 Oct 2025 17:02:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2590820</guid>
    </item>
    <item>
      <title>Study of the Circularity of Recycled Concrete Aggregates Subjected to Different Mechanical and Chemical Treatments</title>
      <link>https://trid.trb.org/View/2551113</link>
      <description><![CDATA[Concrete is one of the most popular construction materials, but it is still not considered sustainable. The introduction of recycled concrete aggregate (RCA) as a substitute for natural aggregate (NA) might make concrete align with the principles of circular economy. Unlike NA, RCA is not a homogeneous material as it is composed of old aggregates and adherent mortar. It is more porous than NA, so it results in lower strength and higher absorption. Several attempts have been made to improve the performance of RCA; however, not all studies prioritize an approach that can be feasible on a large scale. In addition, factors that enhance or decrease the performance of cast concrete mixes include the aggregate gradation, shape, and quantity of fines. The objective of this paper is to assess how the circularity, quantity of fines, roundness, and surface characterization of aggregates changes over time with respect to treatments such as mechanical and chemical treatments that can be extended on a large scale without a strong environmental impact. It was noted that acetic acid results in a superfluous additional element that does not greatly affect the results, since a considerable difference in the circularity, porosity, and fine number of aggregates can be produced by changing the timing and the size of the steel nuts used in the mechanical treatment.]]></description>
      <pubDate>Mon, 12 May 2025 17:08:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2551113</guid>
    </item>
    <item>
      <title>Characterization and Performance Evaluation of Asphalt Mastics Modified with Recycled Concrete Powder</title>
      <link>https://trid.trb.org/View/2531404</link>
      <description><![CDATA[This study investigated the feasibility of using recycled concrete powder (RCP) as an alternative to limestone powder (LP) in asphalt mastic fillers, addressing construction waste management challenges while promoting sustainable development of asphalt pavements. Through multidimensional research incorporating microscopic characterization, performance evaluation, and mechanism analysis, the study systematically examined the effects of RCP on asphalt mastic properties. Results showed that RCP exhibited rough surface texture and high specific surface area, while its elevated MgO content enhanced the asphalt-filler interfacial interaction. The incorporation of RCP improved the high-temperature stability and deformation resistance of asphalt mastic, although performance declined when the replacement ratio exceeded 75%. Rheological tests and fatigue analysis revealed that RCP50 and RCP75 blends demonstrated optimal comprehensive performance. Grey relational analysis identified correlations between filler characteristics and mastic properties, showing that Jnr(diff) values were significantly associated with MgO content and RCP dosage. Multi-criteria evaluation based on the entropy method suggested an optimal RCP replacement ratio of 50-75%. This study provides new insights and theoretical foundation for the utilization of construction waste and enhancement of asphalt pavement performance.]]></description>
      <pubDate>Fri, 02 May 2025 08:49:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2531404</guid>
    </item>
    <item>
      <title>Large-Scale Implementation of Semi-proprietary UHPC With Virgin and Recycled Fibers for Precast Bridge Columns: Material Characterization</title>
      <link>https://trid.trb.org/View/2534058</link>
      <description><![CDATA[Ultra-high performance concrete (UHPC) is gaining popularity for large-scale applications due to its superior mechanical performance and durability. However, the extent of large applications remains limited because of the high cost and carbon footprint of UHPC components like steel fibers. This study aims to incorporate different types of recycled steel fibers (RSF) from landfill tires as an alternative to manufactured steel fibers (MSF) specifically in semi- or non-proprietary UHPC mixtures to realize and validate an ultra-economical UHPC solution. A base UHPC mixture with locally sourced materials is used to produce a total of 13 batches with varying steel fibers type (including different RSF), fiber ratio, and mixing mechanism and scalability. The study specifically focuses on understanding the effects of MSF and raw RSF characteristics, i.e. fibers diameter, length, and aspect ratio on flowability and mechanical properties of UHPC using hundreds of compression, modulus of elasticity, direct tension, and flexural tests. Overall, the study outlines the opportunities and challenges of using RSF in scalable UHPC but also demonstrates, for the first time, the validity of RSF with high aspect ratio and recommends the proper RSF dosage for comparable mechanical behavior as using high-end MSF.]]></description>
      <pubDate>Mon, 14 Apr 2025 17:07:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534058</guid>
    </item>
    <item>
      <title>Mechanical strength of an hot-mix asphalt using recycled concrete aggregate: mass and volume proportioning</title>
      <link>https://trid.trb.org/View/2519028</link>
      <description><![CDATA[The generation of solid waste produced by the construction sector is considered a major problem worldwide. Several studies have been conducted to evaluate the use of construction and demolition wastes (CDW) in pavements. Within CDW, one material with great potential for use is recycled concrete aggregate (RCA). The present study evaluated the mechanical performance of a hot-mix asphalt (HMA) that used RCA as a partial substitute for the coarse fraction of the natural aggregate – Nag (particle size retained on 1/2” and 1/2"+3/8” sieves). The substitution was performed in a conventional way by mass and also by volume. To evaluate the performance under monotonic loading, the stability/flow ratio (𝘚/𝘍) of the Marshall test and the Indirect Tensile Strength (ITS) were measured on dry (𝘐𝘛𝘚𝘥) and conditioned (immersed in water, 𝘐𝘛𝘚𝘸) samples. The tensile strength ratio (TSR) was calculated to evaluate the resistance to moisture damage. Under cyclic loading, tests of resilient modulus – RM (three temperatures and three loading frequencies), permanent deformation, and fatigue resistance under controlled-stress were performed. Cantabro tests were performed to measure the resistance to abrasive wear. Conventional characterization tests and imaging processing in a scanning electron microscope (SEM) were carried out on particles of RCA and Nag. A Life Cycle Cost Analysis (LCCA) was performed with the results obtained. The general conclusions were as follows: (i) RCA increases the asphalt content in the mixes, however, volume substitution could help to decrease it; (ii) the mixes with RCA met the volumetric and strength parameters established by the Colombian specification (especially for roads with low traffic volumes); (iii) mixes with RCA undergo better mechanical performance in all tests performed, however, resistance to moisture damage may be compromised when dosing by volume and asphalt content decreases; (iv) substitution by mass or volume did not generate clear trends in the results, but better overall performance is reported in mixes dosed by volume. It is recommended to carry out more studies where Nag is replaced by RCA in volume.]]></description>
      <pubDate>Thu, 27 Mar 2025 11:37:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2519028</guid>
    </item>
    <item>
      <title>Optimizing Ball Milling for High-Quality Recycled Aggregates: Examining the Mechanical Processing and Performance of Cement-Treated Bases</title>
      <link>https://trid.trb.org/View/2521903</link>
      <description><![CDATA[Producing superior-quality recycled aggregates from demolition waste is challenging. Over the years, mechanical treatment methods for removing attached mortar from aggregates have evolved significantly. The studies on effective recycled coarse aggregate (RCA) processing with optimized processing parameters using ball milling and characterization of processed RCA (RCA) are limited. In this study, central composite design in the response surface method was employed to optimize control process factors (charge, revolution time, and aggregate weight) with aggregate properties as responses (percentage mortar removal, water absorption Wₐ, specific gravity Sg, impact value Iᵥ, and abrasion value Aᵥ). The aggregate processed with optimized processing parameters exhibited superior quality with enhanced physical properties. The effect of the processing of RCA on the mechanical properties of cement-treated bases was studied by utilizing processed RCA in cement-treated recycled concrete aggregate mixes. The microstructural analysis was performed using 3D-surface topography, scanning electron microscopy, and energy dispersive spectroscopy. The test results demonstrated a 63% reduction in water absorption and an improvement in Sg, Iᵥ, and Aᵥ by 12.3%, 38%, and 23.7%, respectively. It is also found that the unconfined compressive strength and flexural strength with processed RCA are improved by 31.5% and 45.7%, respectively. Natural coarse aggregate can be completely replaced with processed RCA in cement-treated bases with the optimized processing method.]]></description>
      <pubDate>Tue, 25 Mar 2025 16:57:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2521903</guid>
    </item>
    <item>
      <title>A High-Performance, Sustainable, Ultra-High-Performance Concrete Material for Highway Bridge Applications</title>
      <link>https://trid.trb.org/View/2498992</link>
      <description><![CDATA[This project will develop a cost-effective, sustainable ultra-high-performance concrete (UHPC) using recycled steel fibers from scrap tires for highway bridge applications. Work in Stage 1 will focus on procuring and characterizing raw materials, followed by UHPC mixture formation and assessments of fresh properties, fiber distribution, and microstructure. An extensive material characterization of all raw materials needed to formulate the UHPC mixture will be performed. A micromechanics guided design approach will be utilized to design reliable and quality UHPC mixtures with 100% recycled steel fiber (RSF). The bond behavior between RSF and a typical UHPC matrix will be characterized and the bonding properties between RSF and UHPC matrix will be utilized to establish a fiber pullout constitutive model for RSF, which will then be integrated into a mesoscale model for fiber reinforced concrete materials to predict the tensile and cracking properties of resulting UHPC mixtures. The fresh properties of various UHPC mixtures, including the rheological characteristics, will also be measured. The fiber distribution and dispersion quality in UHPC will be studied using X-ray computed tomography (CT). The influence of the adhered rubber on the microstructure of UHPC mixtures will be observed via optical microscopy using thin section specimens. In Stage 2, the UHPC mechanical performance will be evaluated. After high-quality UHPC mixtures are formulated, their mechanical properties will be experimentally determined. For life cycle assessment, a hypothetical highway bridge case using the final optimum UHPC material will be created and a life cycle inventory analysis covering all phases of the structure life cycle will be performed. A comprehensive life cycle assessment study will be subsequently carried out to quantify the economic, social, and environmental benefits for the new UHPC structure. Recommendations for future research and implementation will be proposed. The final report will include all relevant data, methods, models, and conclusions along with recommendations, guidelines, and implementation plans.]]></description>
      <pubDate>Tue, 28 Jan 2025 13:02:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2498992</guid>
    </item>
    <item>
      <title>Optimization and Characterization of Ferrochrome and Recycled Concrete Aggregate Mixes for Pavement Base Layers</title>
      <link>https://trid.trb.org/View/2442145</link>
      <description><![CDATA[Utilizing alternate aggregates is crucial for conserving resources, promoting sustainability, and managing waste effectively. The focus of the current study was the utilization of ferrochrome aggregate (FCA) and recycled concrete aggregate (RCA) in cement-treated base layers with the objective of entirely replacing natural coarse aggregate (NCA). The study meticulously prepared cement treated recycled and ferrochrome aggregate (CTRFA) specimens with 3%, 5%, and 7% cement content. These specimens incorporated varying blends of RCA and FCA, ranging from 0% to 100%. Response surface method (RSM) was used to optimize the mixes by considering strength and durability criteria for cement treated bases (CTB). Microstructural characterization was aimed to explore aggregate surface roughness, mortar hardness, mineral phases, cracks, and elements within the matrix. The outcomes of optimization revealed that the optimal mixture, meeting the specifications of the Indian Road Congress, could be achieved by substituting 61% RCA and 39% FCA with 4.8% cement content.]]></description>
      <pubDate>Sat, 30 Nov 2024 15:26:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2442145</guid>
    </item>
    <item>
      <title>Mixture Design Procedure for Recycled Asphalt Pavements</title>
      <link>https://trid.trb.org/View/2441388</link>
      <description><![CDATA[This report describes a procedure that can be used by an engineer to design a recycled mixture using material salvaged from an asphalt concrete roadway that is a candidate for recycling. Techniques are included for directing a study of the distressed pavement to determine the causes of the distress that produced the need for rehabilitation. After the causes of distress have been determined, the engineer can evaluate the salvaged materials to determine (1) if softening agents are needed and (2) if virgin aggregate and asphalt should be added and, if so, how much. Also included are directions for preparing candidate mixtures as well as suggested minimum values for stability and engineering properties. Example plots and tables demonstrate the use of the technique.]]></description>
      <pubDate>Tue, 15 Oct 2024 10:53:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/2441388</guid>
    </item>
    <item>
      <title>A Framework for Considering Resource Availability, Experimental Performance, and Environmental Impacts to Advance Alternative Mineral Admixtures</title>
      <link>https://trid.trb.org/View/2417107</link>
      <description><![CDATA[Concrete is the most used building material. Due to the scale of use, Portland cement and concrete production drive a large portion of the global greenhouse (GHG) emissions. High-GHG-emitting industries are under increased pressure to decrease their GHG impacts to minimize the impacts of climate change and avoid the worst-case climate scenarios. As Portland cement production is the primary driver for the GHG emissions of cement-based materials, partially replacing Portland cement with supplementary cementitious materials (SCMs) and/or mineral fillers is one of the primary strategies for reducing the clinker content of binder materials. However, the supply of common SCMs is already regionally restricted with constrained supplies of coal fly ash (fly ash) and ground blast furnace slag (GBFS) available for cement-based material production. Notably, as the high-GHG emitting electricity and metal industries work to decrease their own GHG impacts, the generation of fly ash and GBFS will decrease and further restrict the availability of SCMs that decrease the GHG emissions of Portland cement-based binders. Alternative mineral admixtures are needed to meet the continued demand. In this work, alternative mineral admixtures are investigated. Specifically, regionally available flows from agricultural rice hull and rice straw residues and post-consumer flows from waste carpet in Northern California are evaluated using experimental characterization coupled with material flow analysis and environmental impact assessment. Insights from these efforts are then used to present a national-level analysis of material availability and identify promising alternatives.]]></description>
      <pubDate>Sun, 18 Aug 2024 11:28:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2417107</guid>
    </item>
    <item>
      <title>Mechanical characterization of fiber-reinforced rubberized recycled concrete</title>
      <link>https://trid.trb.org/View/2320510</link>
      <description><![CDATA[Dumping non-biodegradable wastes, such as construction and demolition waste (CDW) and scrap tires, is causing significant environmental problems. Thus, this study used recycled coarse aggregate (RCA) and crumb rubber (CR) procured from CDW and scrap tires as a partial replacement of natural aggregates. 30% natural coarse aggregate (NCA) was replaced by RCA, and 0%, 5%, 10% and 15% natural fine aggregate (NFA) was replaced by CR. Besides these, 0.5% polypropylene (PP) fiber was incorporated into the concrete mixtures. Different physical and mechanical properties of rubberized recycled concrete (R²C) and fiber-reinforced rubberized recycled concrete (FR²C) were investigated. Microstructural analysis, chemical analysis, failure modes, and cost-effectiveness were also evaluated. Simplified regression equations have been proposed to predict various mechanical properties of R²C and FR²C mixtures. The inclusion of RCA, CR, and fiber decreased the slump value of the fresh concrete up to 69.7%. The compressive strength decreased with an increase in CR percentage, but it increased by including fiber content. Though all the R²C and FR²C specimens exhibited lower tensile and flexural strength, a marginal reduction was found in FR²C specimens containing up to 5% CR content, which was only 3.3% and 6.8% lesser compared to the control samples. The surface resistivity test revealed that the chloride ion penetrability may be very low for all the combinations of R²C and FR²C specimens. By raising the percentage of CR, the UPV decreased, but the addition of PP fiber slightly increased the value. The cost analysis results pointed out that both the R²C and FR²C combinations saved more energy (up to 2.22 times) and decreased fuel consumption (up to 20.2%). Finally, the present study will aid in advancing sustainable fiber-reinforced rubberized recycled concrete.]]></description>
      <pubDate>Thu, 22 Feb 2024 09:06:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2320510</guid>
    </item>
    <item>
      <title>Characterization of Recycled Aggregates in Existing Pavement Base Layers</title>
      <link>https://trid.trb.org/View/2286525</link>
      <description><![CDATA[The use of recycled pavement materials in transportation infrastructure projects has contributed positively to maintaining a sustainable flow of construction materials and sources. Geotechnical properties of recycled pavement materials play a major role in the suitability of such materials for use in civil infrastructure. This study aimed at evaluating the properties of recycled concrete aggregates (RCA) and reclaimed asphalt pavements (RAP) used as base layer materials in existing hot mix asphalt pavements (with service life of more than 8 years) and comparing them with virgin crushed aggregate (CA) base materials of similar service life. Coring of flexible pavement surface layers at 18 pavement sites was performed to expose the base course layer materials for sampling and testing. Then, the dynamic cone penetrometer (DCP) test was conducted in which the cone penetrated through base layers to the subgrade when possible. Thereafter, base materials were retrieved from the pavement sites for laboratory testing and evaluation. Laboratory tests consisted of particle size analysis, specific gravity and absorption, and Micro-Deval abrasion. Analysis of the particle size distribution showed the presence of high sand size fractions in both RCA and RAP base materials compared with virgin CA base materials. This indicated the recycled materials were crushed/milled to smaller size fractions or degraded under freeze-thaw cycles and traffic loads during the pavement’s service life, or both. The RCA base materials exhibited the highest absorption and mass loss in the Micro-Deval test. The DCP test results were used to predict California bearing ratio (CBR) and resilient modulus (Mr) of base materials. The predicted CBR and resilient modulus of the recycled base materials showed that RCA, RAP, and CA all had comparable strength and modulus values that were high. The investigated recycled RCA and RAP aggregates possessed properties that are comparable with the properties of the virgin CA.]]></description>
      <pubDate>Fri, 29 Dec 2023 16:29:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2286525</guid>
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