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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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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Concrete Technology for Transportation Applications</title>
      <link>https://trid.trb.org/View/1682281</link>
      <description><![CDATA[This synthesis documents how state departments of transportation select and deploy concrete technologies in the construction of transportation facilities.  Information used in this study was gathered through a literature review, a survey of state departments of transportation, and follow-up interviews with selected agencies, resulting in case examples of concrete technologies. The literature review included standard practices, reports, and technical papers. These represent, but are not limited to, the American Concrete Institute’s standard practices, along with reports from the Federal Highway Administration, state departments of transportation, and industry, as well as research papers from domestic and international universities and research organizations.  The literature review showed that implementation of advanced, emerging, and new concrete technologies has resulted in major benefits to the transportation infrastructure. The benefits include accelerated construction, replacement and repairs of pavements and bridges, better performance and improved durability, control of temperature in massive structural members to mitigate thermal cracking and improve durability, and enhanced sustainability and environmental benefits.  The survey responses showed that the most implemented concrete technologies are high-strength concrete, self-consolidating concrete, high early strength concrete, and lightweight concrete.  Other findings and information gaps are presented in detail.]]></description>
      <pubDate>Thu, 06 Feb 2020 13:27:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1682281</guid>
    </item>
    <item>
      <title>Laboratory evaluation of treated recycled concrete aggregate in asphalt mixtures</title>
      <link>https://trid.trb.org/View/1628162</link>
      <description><![CDATA[Recycled Concrete Aggregate (RCA) is considered to be a potential substitute for natural aggregates in asphalt mixtures. Despite some contradictory results achieved by researchers, it is believed that RCA treatment can improve quality of recycled asphalt mixes considerably. In this research, a two-stage treatment was applied on coarse RCA materials in order to improve their properties. The treatment consisted of first soaking RCAs in Hydrochloric Acid (HCl); second impregnating the treated RCAs into Calcium Metasilicate (CM). The pores of RCAs were filled with CM particles. Substituting virgin aggregates with different amounts of coarse RCA materials into hot mix asphalt (HMA) resulted in increased tensile properties of mixes as tested in indirect tensile fatigue test (ITFT). The treatments resulted in reduced moisture sensitivity of mixes. The improvements were mostly attributed to the reduced water absorption of RCA materials. Moreover, morphological characteristics of the treated coarse RCA materials were determined using Scanning Electron Microscopy (SEM) photography.]]></description>
      <pubDate>Wed, 14 Aug 2019 14:31:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1628162</guid>
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    <item>
      <title>Characterization of Recycled Concrete Aggregate after Eight Years of Field Deployment</title>
      <link>https://trid.trb.org/View/1595329</link>
      <description><![CDATA[Recycled concrete aggregate (RCA) is a high-quality substitute for virgin aggregate as base or subgrade material in pavement construction. However, heavy metal leaching and/or production of high pH leachate are environmental risks commonly associated with the use of RCA. To characterize changes in physical and chemical properties after use, RCA base course and subgrade soil samples were recovered from the Minnesota road research (MnROAD) field site after eight years and compared to the original RCA physical and chemical characteristics. RCA samples were analyzed to determine their mineralogy, carbonate content, acid neutralization capacity (ANC), material pH, and trace element leaching potential. ANC was higher in the recovered RCA and higher for the fine-grained RCA particles than the coarse particles, which was confirmed by extensive carbonation of the fines fractions during field deployment. Material pH of RCA and subgrade soil samples were significantly higher than leachate pH measured in previous and current field investigations of this site, suggesting that conventional laboratory techniques do not represent field conditions and should be modified to better represent field conditions.]]></description>
      <pubDate>Fri, 29 Mar 2019 10:20:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1595329</guid>
    </item>
    <item>
      <title>Effects of reclaimed asphalt materials on geotechnical characteristics of recycled concrete aggregates as a pavement material</title>
      <link>https://trid.trb.org/View/1593645</link>
      <description><![CDATA[The use of recycled concrete aggregates (RCAs) as an unbound pavement material is a perfect alternative to effectively manage the construction and demolition (C&D) wastes. However, the presence of constituents in RCA is led for inconsistent properties. The reclaimed asphalt pavement (RAP) material is one of the major constituents that can be mixed at the recycling process of demolished concrete. Therefore, this study aims to investigate the effects of RAP as a constituent in RCA, on its characteristic properties as an unbound pavement material. To achieve the objectives of the study, five RCA samples were produced by mixing different percentages of RAP by weight. A series of standard laboratory tests were conducted on each sample. The results were then compared with the properties of standard granular pavement materials specified by Queensland Department of Transport and Main Roads (QDTMR), Australia. The analysis depicted that the presence of RAP as a constituent in RCA up to 15% was not significantly affected on the physical properties of RCA as an unbound pavement material.]]></description>
      <pubDate>Fri, 29 Mar 2019 10:15:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1593645</guid>
    </item>
    <item>
      <title>Utilization of Recycled Concrete Aggregate (RCA) in French Drain System: A Full-Scale Study</title>
      <link>https://trid.trb.org/View/1572538</link>
      <description><![CDATA[The utilization of recycled concrete aggregate (RCA) as a backfill material in an exfiltration drainage system such as French drain has been studied in a laboratory-scale over the past decade. In previous studies, the reduction of filter fabric permittivity can be caused by the total amount of RCA fine contents, the accumulation of calcite precipitation and the hydration of anhydrous cement grains. Laboratory-based tests are necessary to characterize RCA as a drainage material and determine the variables which affect and cause the clogging potential of a drainage system. The laboratory-based tests, however, have limitations compared to the full-scale test as well as tests under the actual field conditions. Therefore, it is necessary and sufficient to setup in-situ/full-scale experiments which can simulate 3-D flow in a drainage system and short- and long-term performances. French drainage system, a common drainage system in the United State, which consists of RCAs as backfill material, has been built in a field as a comparison of a French drain system with natural aggregates (Limestone). Each RCA French drain system contains a different percentage of RCA fines (0, 2 and 4%). The design and construction of French drain system with RCA are described. Flow rate and discharge rate of groundwater have been monitored to evaluate the short- and long-term performances of RCA French drain system. The results of flow rate and discharge rate show that RCA French drain performs similar if not better than limestone. In addition, the performance of French drain systems is highly dependent on the geological condition (e.g. in-situ soil); however, excessive fines can cause large reductions in flow rate over time.]]></description>
      <pubDate>Sat, 02 Mar 2019 15:41:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1572538</guid>
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    <item>
      <title>Utilisation of construction and demolition materials with clay for road pavement subgrade</title>
      <link>https://trid.trb.org/View/1589229</link>
      <description><![CDATA[This paper presents the use of construction and demolition (C&D) materials with clay, and a comparative study on the C&D and natural aggregate (NA) utilisation for road pavement subgrade. California bearing ratio (CBR), unconfined compressive strength (UCS), and swelling tests were conducted to analyse the response of recycled concrete aggregate (RCA), dragged asphalt pieces (DAP), and natural gravel aggregate (NA) mixed with a low plasticity clay at various contents (0%, 10%, 20%, 30%, 40%, 50%, and 100%) by dry weight. The laboratory tests indicated that the use of clay in all the aggregates resulted in sharp increase in the unconfined compressive strength (UCS) values. The CBR analysis showed an 80%, 75%, and 50% decrease in the performance of NA, RCA, and DAP with 50% clay, respectively. Further, the testing results also revealed a slight increase in the swelling percentage of the mixtures by clay additions. Consequently, this research has implications in the design of road pavement subgrades for the field performance of gravel-size-waste and/or NAs and clay mixtures.]]></description>
      <pubDate>Thu, 28 Feb 2019 16:37:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1589229</guid>
    </item>
    <item>
      <title>Mechanical properties and strength criteria of cement-stabilised recycled concrete aggregate</title>
      <link>https://trid.trb.org/View/1578601</link>
      <description><![CDATA[The 7, 28, 60 and 90 day mechanical properties of cement-stabilised recycled concrete aggregate (CSRCA) were experimentally tested, including unconfined compressive strength (UCS), resilient modulus, splitting strength and flexural-tensile strength. According to the test results, the strength growth equations and relation models of mechanical indexes are established innovative. The strength criteria of CSRCA against fatigue failure was proposed based on load response of pavement, mechanical and fatigue properties of CSRCA as well as Miner’s theory of fatigue accumulation. Results showed that when the curing age was smaller than 60 days, the UCS and resilient modulus of CSRCA showed a V-shaped variation with the increase of recycled concrete aggregate (RCA) dosage, and decreased with the increasing of RCA content when the curing age was 90 days. Splitting strength and flexural-tensile strength of CSRCA increased slightly with the increase of RCA dosage. A fatigue equation of CSRCA was established, which reflected that the fatigue life of CSRCA increased slightly with the increase of RCA dosage. The strength growth equations could represent strength growth characteristics of CSRCA accurately. The UCS and splitting strength criteria of CSRCA against fatigue failure were proposed, which were correlated with pavement structure and layer, material properties and service life. It realised the goal of structure-material integrated control of CSRCA base or sub-base fracture.]]></description>
      <pubDate>Mon, 28 Jan 2019 11:33:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1578601</guid>
    </item>
    <item>
      <title>Behavioural study of pavement quality concrete containing construction, industrial and agricultural wastes</title>
      <link>https://trid.trb.org/View/1541093</link>
      <description><![CDATA[This study proposes the use of industrial and agricultural wastes as mineral admixtures for enhancing the mechanical and durability aspects of concrete containing recycled concrete aggregates derived from concrete waste. The study was carried out by testing specimens prepared from concrete mixes with and without recycled concrete aggregates and three different mineral admixtures viz: fly ash (an industrial waste), rice husk ash and bagasse ash (agricultural wastes) for their compressive strength, flexural strength, split tensile strength, workability, chloride ion concentrations, carbonation, sorptivity and abrasion resistance in order to assess the variations and improvements. It was observed that concrete mix upon incorporating mineral admixtures showed significant improvement in both mechanical and durability properties when compared to concrete mix with recycled concrete aggregates alone. Fly ash admixed mixes showed a gain of 15% and 24% for compressive and flexural strength parameters, while the gain for rice husk ash mix and bagasse ash mixes was observed to be 12% and 25%, 13% and 20% respectively when compared to recycled aggregate concrete mix without mineral admixtures. Improvements in durability aspects were observed by incorporating mineral admixtures supported by lower parameters for water absorption, sorptivity coefficients and chloride ion concentrations and increased hydration products as concluded from scanning electron microscopic investigations.]]></description>
      <pubDate>Thu, 11 Oct 2018 17:06:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1541093</guid>
    </item>
    <item>
      <title>Comparison of response for three different composite pavement sections to environmental loads</title>
      <link>https://trid.trb.org/View/1540670</link>
      <description><![CDATA[Composite pavement structures are constructed mainly either as Portland cement concrete (PCC)-over-PCC or hot mix asphalt (HMA)-over-PCC. Several successful in-service projects have been reported in Europe. The design and construction of these sections in the United States, however, still require effort. The current study includes the analysis of the response of three different composite pavement sections to the environmental loads. These sections were constructed in May of 2010 at the Minnesota Road Research Facility. The sections are constructed in three individual cells, Cell 70, a HMA-over-PCC with recycled concrete aggregate (RCA), Cell 71, exposed aggregate concrete (EAC)-over-RCA and Cell 72, EAC-over-economical concrete. All cells were heavily instrumented with thermocouples, moisture sensors, and static and dynamic strain gauges. This study characterises the structural response of HMA-over-PCC pavements and also PCC-over-PCC to the environmental loads.]]></description>
      <pubDate>Mon, 01 Oct 2018 14:39:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1540670</guid>
    </item>
    <item>
      <title>Enhancing Mechanical and Durability Properties of Recycled Aggregate Concrete</title>
      <link>https://trid.trb.org/View/1523719</link>
      <description><![CDATA[The main difference between Recycled Concrete Aggregate (RCA) and Natural Aggregate (NA) is the mortar adhered on RCA. This paper presents the effect of RCA to concrete and a treatment method utilized to improve the properties of RCA, by reducing the amount of the adhered mortar, and therefore the properties of the Recycled Aggregate Concrete (RAC). Mineral admixtures were used as partial replacement of cement. Three types of coarse RCA and two types of mineral admixtures were used (fly ash and silica fume). In addition, the RCA were employed as internal curing (IC) agents in concrete mixtures to assess their effectiveness in enhancing the properties of concrete. The mechanical properties and durability of RAC were improved using the proposed methodologies. Cost analysis showed that RAC mixtures could be less expensive than NA mixtures.]]></description>
      <pubDate>Mon, 27 Aug 2018 14:06:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1523719</guid>
    </item>
    <item>
      <title>Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregate</title>
      <link>https://trid.trb.org/View/1508837</link>
      <description><![CDATA[The presence of attached mortar is the main reason for lower quality of recycled concrete aggregate (RCA) compared to that of natural aggregate. Hence, its use is limited up to 30% replacement of natural aggregate at present. The attached mortar of the RCA can be removed by mechanical treatment, acid treatment, thermal treatment (500 to 750°C [932 to 1382°F]), and microwave treatment. There are difficulties—such as achieving high temperature and treating larger quantities of RCA with acid and a microwave oven—in applying these treatments at field level. Hence, the present study focuses on a combination of heating (250°C [482°F]) and mechanical treatment to improve the quality of the RCA. This method removed 70 to 80% of attached mortar of the RCA. Properties of RCA such as bulk density, specific gravity, water absorption, and crushing value were discussed in detail. Post-treatment, it was observed that the properties of treated RCA improved compared to untreated RCA, but still they were found to be poorer than natural aggregate. The experimental studies were carried out to overcome the aforementioned drawbacks of the recycled aggregate concrete by incorporation of mineral admixtures. It was found that the use of mineral admixtures in concrete produced with treated RCA enhances both the mechanical and durability properties. Thus, the concrete produced with treated RCA and mineral admixture will lead to sustainable development.]]></description>
      <pubDate>Tue, 29 May 2018 16:05:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1508837</guid>
    </item>
    <item>
      <title>Performance evaluation of asphalt mixtures containing recycled concrete aggregates</title>
      <link>https://trid.trb.org/View/1505416</link>
      <description><![CDATA[To evaluate the feasibility of using Recycled Concrete Aggregates (RCA) in asphalt mixtures, the coarse RCA and fine RCA were prepared as a partial replacement of the natural aggregates (NA). Different amounts of replacement of NA with RCA were investigated, and the mechanical properties and pavement performance of asphalt mixtures containing different proportions of RCA were analysed based on laboratory tests. The results indicated that with increasing the RCA percentage, the optimum asphalt content increased and the bulk density of mixtures decreased as well. Mixtures containing 40% coarse RCA or 20% fine RCA both showed satisfactory performance. Besides, the mixture containing 40% fine RCA had the highest asphalt content, but gave much better performance compared to the virgin mix except for its bad resistance to permanent deformation. Finally, the pavement performance of mixtures containing 60% coarse RCA and 50% coarse RCA were unacceptable.]]></description>
      <pubDate>Sat, 28 Apr 2018 12:37:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/1505416</guid>
    </item>
    <item>
      <title>Evaluation of the concrete prisms test method for assessing the potential alkali-aggregate reactivity of recycled concrete aggregates</title>
      <link>https://trid.trb.org/View/1493515</link>
      <description><![CDATA[The concrete prism test (CPT) is a widely used method for assessing the potential alkali-aggregate reactivity of any given natural aggregate. This paper presents the evaluation of the current method and its applicability to assess the alkali-silica reactivity of recycled concrete aggregates (RCA). The testing was carried out on two different types of RCA: manufactured from > 15 years old blocks disposed outdoors and from a demolished overpass infrastructure. Following the analysis of the different parameters that make RCA different than original aggregates, it has been found that the residual mortar content of the RCA particles and their absorption condition prior to their addition to mixtures are considerably important. The CPT is reliable to access RCA reactivity, however, it is therefore recommended to use saturated RCA as higher expansion is obtained under these conditions. It is also recommended to use the aggregate dry rodded bulk density to determine the coarse aggregate-to-sand ratio, instead of using a fixed 60 to 40 ratio. Moreover, no pessimum effect was observed using RCA; in fact, the expansion of the test prisms was increasing with increasing RCA content. The extent of damaged suffered by the concrete from which the RCA are manufactured and the geology of the original virgin aggregates incorporated in the RCA are also important parameters to consider while using the CPT to assess correctly each RCA reactivity.]]></description>
      <pubDate>Sun, 14 Jan 2018 17:58:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1493515</guid>
    </item>
    <item>
      <title>Evaluation of Reclaimed Asphalt Pavement and Recycled Concrete Aggregate as a Dense Graded Aggregate Base Course</title>
      <link>https://trid.trb.org/View/1492223</link>
      <description><![CDATA[This report documents the laboratory and field study of reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) for use in base course. The study was conducted to confirm the recently adopted RAP specifications, and investigates the engineering properties such as gradation, degradation, resilient modulus and permanent deformation of RAP, RCA and blended 75% dense graded aggregate (DGA) with 25% RAP, and compares these properties with DGA. Four base course projects with RAP, RAP/DGA blend, and DGA for comparison were constructed to investigate and confirm the constructability, density, and rutting potential. The use of 100% RAP base course in place of DGA is confirmed for low and medium traffic pavements. Since RCA has been used successfully for several years as base course, no test projects were constructed to confirm the use of RCA base course. The use of RAP/DGA blend is also confirmed for use in base course.]]></description>
      <pubDate>Thu, 28 Dec 2017 14:03:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1492223</guid>
    </item>
    <item>
      <title>Durability Assessment of Recycled Concrete Aggregates for Use in New Concrete – Phase II
Report</title>
      <link>https://trid.trb.org/View/1477524</link>
      <description><![CDATA[This Phase II investigation into the durability of new concrete incorporating recycled concrete aggregates (RCA) focused on several goals: 1) Provide corroboration of results obtained in Phase I for a multi-laboratory study related to assessing alkali-silica reactivity (ASR) of RCA in accelerated laboratory tests; 2) Investigate the efficacy of mitigation methods to control ASR in concrete containing potentially reactive RCA; 3) Establish long-term data through placement of concrete blocks containing RCA in an outdoor exposure site in Laramie, WY; and 4) Survey state departments of transportation (DOTs) and other transportation agencies about their perceptions and usage of RCA ASR in concrete within their agency and how that may be improved through the use of a database tracking tool. From Phase II the following main conclusions were drawn: 1) The coefficient of variation limits in ASTM C 1260-07 do not apply to concrete mortar bars incorporating RCA. It is recommended that further testing, using different RCA and more laboratories (at least six), should be completed before a new standard for RCA and/or incorporation of RCA into the current ASTM C 1260 test may be allowed. 2) Generally, as the replacement level of RCA was reduced, the amount of supplementary cementitious material (SCM) needed to control deleterious ASR also decreased for the RCA sources investigated in this study. 3) Ternary blends containing metakaolin resulted in the most significant decrease in expansions compared to the mixtures with no SCMs. The results of the transportation agency survey showed the following: 1) A vast majority of agencies believed that sustainability was important to their agency and that it was addressed in a clear and meaningful way. 2) A majority, 54%, of agencies believed they had specific guidance for the use of RCA in new concrete; however, only 15% believed that there was strong information from the federal level about the use of RCA in new construction. 3) Of all respondents, 77% indicated their agency was concerned about ASR in concrete in general for their agency. 4) The biggest barriers to using RCA were noted as concerns about quality, a lack of standards and specifications, and unclear guidance on the testing of RCA. 5) The biggest concerns specific to a source of RCA when considering it for use in new construction were increased shrinkage concerns, ASR and residual chlorides. 6) The most sought-after information about a potential RCA source when considering it for use were the existing condition of the RCA when it was taken out of service, the reason it was taken out of service, whether repairs were performed to the structural element taken out of service, and the age of the RCA.]]></description>
      <pubDate>Mon, 07 Aug 2017 12:32:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1477524</guid>
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