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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
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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>A Comprehensive Guideline for GDOT Bridges Fire Hazard Assessment</title>
      <link>https://trid.trb.org/View/2681206</link>
      <description><![CDATA[Bridge fires can cause rapid and severe loss of structural capacity. This loss of capacity often leads to major safety risks, network disruptions, and high economic impacts. A curated history of United States bridge fires in the 20th and 21st centuries is presented. This history identifies recurring ignition sources, contributing factors, and damage patterns associated with bridge fires. The research team further synthesizes current knowledge on critical temperatures and heat-induced defects in steel and concrete. They evaluate rapid nondestructive testing (NDT) methods that can be used for a post-fire triage inspection. Integrating the historical case studies, common trends found in the historical record of bridge fires, material behavior, and NDT information, the team presents practical guidance to support post-fire triage of highway bridges. In addition, they propose a methodology that may be implemented to develop a single, easy-to-use universal model to determine the residual structural capacity of fire damaged concrete. Laboratory burn testing of concrete samples was conducted to quantify residual compressive strength as a function of changes in rebound hammer values and ultrasonic pulse velocity. During testing, the model produced a standard error of 8 percent for estimating residual compressive strength. This indicates promise for refinement with further testing. A three-factor model that incorporated visual cues was also developed. The three-factor model improved overall fit but raised concerns about robustness and practical reliability. The report concludes with recommendations for post-fire inspection procedures, expanded training for bridge and maintenance personnel, and wider availability of NDT equipment to support timely, consistent, and defensible triage decision following bridge fires.]]></description>
      <pubDate>Thu, 19 Mar 2026 08:56:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2681206</guid>
    </item>
    <item>
      <title>Electrical Resistivity Testing of Concrete Cylinders: Bias, Precision, and Use in Process Control</title>
      <link>https://trid.trb.org/View/2449551</link>
      <description><![CDATA[Electrical resistivity is increasingly used as a test method to assess the transport properties of concrete. This paper describes an interlaboratory study that was conducted to determine precision and bias for resistivity measurements made in surface and bulk configurations of concrete cylinders. Tests were performed following AASHTO T 358-22 and AASHTO T 402-23. A verification device is introduced with a known resistivity (and impedance) to aid in determining the bias associated with resistivity measurements. However, this device can also be used as a training tool and as a tool to evaluate the qualifications of those new to performing the test. Concrete cylinders were prepared, cured, and conditioned using three methods: immersed in simulated pore solution, sealed, and immersed in lime solution. The samples were tested to determine the precision in the resistivity measurements of the samples for the different curing conditions. The paper discusses how resistivity testing can be used for quality control testing as well as quality acceptance. The results were used to develop precision and bias statements for resistivity measurements, which have been adopted in the latest American Association of State Highway and Transportation Officials (AASTHO) standards.]]></description>
      <pubDate>Mon, 11 Nov 2024 10:48:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2449551</guid>
    </item>
    <item>
      <title>I-70 Reconstruction Grainfield, KS: Summary Report</title>
      <link>https://trid.trb.org/View/2262753</link>
      <description><![CDATA[The Federal Highway Administration (FHWA) Mobile Concrete Technology Center (MCTC) visited the I-70 pavement replacement project in Grainfield, Kansas from July 29 to August 8, 2019. The objective of the MCTC visit was to demonstrate innovative technologies currently in the implementation phase; this site visit is in conjunction with monitoring and testing work being done on this project using FHWA Performance Engineered Mixtures (PEM) Implementation Incentive funding. During this visit, the MCTC conducted a PEM Open House on August 8, 2019 in coordination with the National Concrete Pavement Technology Center (CP Tech Center), and Todd LaTorella of the Missouri-Kansas Concrete Paving Association. A planned companion workshop titled “Ensuring Quality in the Concrete Paving Process” has been deferred until in-person training events can be held. This report summarizes the test results, observations, and other activities conducted during this visit. Numerical values of the test results are presented in the Appendices.]]></description>
      <pubDate>Wed, 11 Oct 2023 15:34:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2262753</guid>
    </item>
    <item>
      <title>US 20 Expansion Holstein, IA: Summary Report</title>
      <link>https://trid.trb.org/View/2262754</link>
      <description><![CDATA[The Federal Highway Administration (FHWA) Mobile Concrete Trailer (MCT) visited the US-20 expansion project in Holstein, IA from July 8 to 13 and July 29 to Aug 3 at the request of Todd Hanson with the Iowa Department of Transportation. The objective of the MCT visit was to demonstrate innovative technologies currently in the implementation phase; this is in conjunction with the work being done on this project using FHWA Performance Engineered Mixtures (PEM) Implementation Incentive funding. The MCT Open House was conducted in coordination with the PEM presentation and the event was very well attended. The Iowa Concrete Paving Association (ICPA) and the National Concrete Pavement Technology Center assisted with this event. This report summarizes the test results, observations, and other activities conducted during this visit. Numerical values of the test results are presented in the Appendix.]]></description>
      <pubDate>Wed, 11 Oct 2023 15:34:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2262754</guid>
    </item>
    <item>
      <title>Concrete Overlay on I-35 Forest Lake, MN: Summary Report</title>
      <link>https://trid.trb.org/View/2262752</link>
      <description><![CDATA[The Federal Highway Administration (FHWA) Mobile Concrete Trailer (MCT) visited the concrete overlay project over I-35 in Forest Lake, MN from July 16 through 26 at the request of Maria Masten with the Minnesota Department of Transportation. The objective of the MCT visit was to demonstrate innovative technologies currently in the implementation phase; this is in conjunction with the work being done on this project using FHWA Performance Engineered Mixtures Implementation Incentive funding. This report summarizes the test results, observations, and other activities conducted during this visit. Numerical values of the test results are presented in the Appendix.]]></description>
      <pubDate>Wed, 11 Oct 2023 15:34:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2262752</guid>
    </item>
    <item>
      <title>Field-Curing Methods for Estimating Early Opening Strength of Cement Concrete Pavement to Traffic</title>
      <link>https://trid.trb.org/View/2117747</link>
      <description><![CDATA[The primary objective of this study was to evaluate field-curing methods of cement concrete cylinders and beams for estimating the early opening strength of pavement to traffic. One concrete pavement mixture was used for casting a total of 60 – 100 mm x 200 mm (4 in. x 8 in.) cylinders, 60 – 150 mm x 300 mm (6 in. x 12 in.) cylinders, and 30 – 150 mm x 150 mm x 500 mm (6 in. x 6 in. x 20 in.) beams. Further, six small – 600 mm x 600 mm x 200 mm (24 in. x 24 in. x 8 in.) and six large – 900 mm x 900 mm x 300 mm (36 in. x 36 in. x 12 in.) test slabs were also cast outdoors for mimicking concrete pavement and field conditions. Half of the above specimens and slabs were cast and cured outdoors in warmer temperatures and the remaining half in colder temperatures. Concrete cylinders were cured using three different methods, namely, ambient air, insulated box/cooler, and power-operated box. Beams were cured using two different methods, namely, ambient air and insulated plywood box. The cast-in-place (CIP) specimens from each slab and cylinders were tested for compressive strength, and beams were tested for flexural strength after 1, 3, and 7 days of curing. Overall, it was found that field-curing of 150 mm (6 in.) cylinders inside insulated box (cooler) can estimate early (1 to 3 days) opening strength of cement concrete pavement within acceptable range.]]></description>
      <pubDate>Fri, 24 Feb 2023 09:05:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2117747</guid>
    </item>
    <item>
      <title>Optimization of Parameters of the New Turner-Fairbank Alkali-Silica Reactivity Susceptibility Test (T-Fast)</title>
      <link>https://trid.trb.org/View/2040278</link>
      <description><![CDATA[Prevention is an effective strategy to avoid damage caused by the alkali-silica reaction (ASR) in concrete structures. The effectiveness of this strategy heavily depends on the use of reliable accelerated tests to determine if an aggregate used in the concrete has the potential to cause ASR. Recently, a new provisional standard test, AASHTO TP 144-21, Determining the Potential Alkali–Silica Reactivity of Coarse Aggregates (TFHRC-TFAST), has been approved by the American Association of State Highway and Transportation Officials. The test accurately predicted the ASR-induced expansion of aggregates used in more than 50 different mortar and concrete samples, including concrete blocks in outdoor testing facilities and concrete in the field. This manuscript presents the results of the collaborative study among three laboratories conducted as part of an overall effort to standardize the new AASHTO TP 144-21. The objectives of the study were to evaluate the suitability of wavelength dispersive x-ray fluorescence (WDXRF) spectroscopy as the main analytical technique, determine the optimal particle size and effect of moisture on calcium oxide (CaO), and evaluate sample preparation on the results. A total of 18 aggregates were evaluated under the TP 144-21 using 4 different CaO samples and 2 sample preparation protocols. The results indicated that the alkali-silica reactivity of the aggregates can be accurately determined by using WDXRF. Upon exposure to the atmosphere, CaO reacts rapidly with moisture to produce calcium hydroxide [Ca(OH)2]. The particle size distribution and amount of Ca(OH)2 in the CaO influenced the ASR classification of marginal (moderately and slow reactive) and nonreactive aggregates. The researchers obtained optimal results using a reagent grade powder CaO with an average particle size of 4.6 µm and less than 5 % of Ca(OH)2. These conclusions were important to validate and optimize the TP 144-21 protocol before launching a wider interlaboratory study.]]></description>
      <pubDate>Fri, 16 Dec 2022 09:58:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2040278</guid>
    </item>
    <item>
      <title>Development of Specifications for High-Performance Fiber Concrete for Nevada</title>
      <link>https://trid.trb.org/View/2035629</link>
      <description><![CDATA[The project stated with an extensive summary of construction practices and experiences from different state agencies. Besides, a detailed summary of state DOT specifications was included in the report. The main objective of this study was to develop a mix design adjustment method for High-Performance Fiber Reinforced Concrete (FRC) that would maintain appropriate workability while improving hardened concrete performance. A literature review was conducted to examine existing methods for adjusting mix designs to account for fiber introduction. It was found that while increasing fine aggregate and cement paste content can make up for lost workability with the addition of fibers, no rational mix design adjustment method is available. Reference mix designs from the Nevada Department of Transportation and the Nebraska Department of Transportation were used, and this study focused on tailoring the mix design based on the parameter of excess paste. Excess paste serves to coat the aggregate particles and is critical for workability. To apply this method, a modified version of ASTM C29 was used to determine the void content of fiber-aggregate skeletons with varying fiber contents. Paste and fine aggregate content were then adjusted to maintain the excess paste quantity between reference mixes and mixes with fiber. A variety of tests, including slump, vibrated L-box, compressive strength, splitting tensile strength, flexural strength, drying shrinkage, and restrained shrinkage were conducted to evaluate the overall concrete performance. Results indicated that, for each mix design, adjusting based on excess paste provided a workable FRC with improved hardened performance. Eight slabs were then prepared for a large-scale examination of the constructability and mechanical behavior of the developed FRC. Throughout the study of FRC, an alternative concrete to Ultra-High Performance Concrete (UHPC) that would considerably outperform High-Performance Concrete (HPC) was developed. This study delves into the development of a new type of concrete called Super High-Performance Concrete (SHPC). SHPC is a high strength, self-consolidating HPFRC that would significantly cut back on cost and production limitations compared to UHPC as it can be produced with conventional drum-type mixers. Results indicate that SHPC outperforms HPC in matters of workability, compressive strength, flexural strength, and toughness and could potentially be a viable alternative of UHPC for applications such as bridge deck connections and overlays. The report also included detailed recommendations regarding the mix design, batching and mixing, quality control methods, and casting of HPFRC and SHPC that can be further used in the development of specifications for NDOT.]]></description>
      <pubDate>Wed, 26 Oct 2022 09:39:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2035629</guid>
    </item>
    <item>
      <title>Establishing Fresh Properties of Fiber Reinforced Concrete for Performance Engineered Mixture (PEM)</title>
      <link>https://trid.trb.org/View/2027097</link>
      <description><![CDATA[The addition of macro or structural fibers into concrete enhances its post-cracking performance. The objective of this study was to conduct a laboratory investigation to determine the influence of structural fibers on the fresh concrete test parameters (Super air meter (SAM) number, V-Kelly index, and Box test rating) recommended for the performance engineered mixture (PEM) procedure. As many as fifty-seven different concrete mixes were designed and prepared, varying fiber types and dosages, aggregate types, and air contents of the concrete. Various fresh and hardened concrete tests were conducted on each of the mixes, and the results were used to determine the influence of the structural fibers on the fresh and hardened concrete properties. The study recommended the allowable range of the SAM number and provided necessary guidance on the box test rating and V-Kelly index for the fiber-reinforced concrete mixtures to be designed as per the PEM procedure.]]></description>
      <pubDate>Mon, 24 Oct 2022 10:22:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2027097</guid>
    </item>
    <item>
      <title>Guidance to Reduce Shrinkage and Restrained Shrinkage Cracking</title>
      <link>https://trid.trb.org/View/2019533</link>
      <description><![CDATA[This document discusses the principles and practices related to reducing shrinkage and shrinkage cracking in concrete elements. The focus of this document is primarily on material properties, construction practices, and environmental considerations. The driving forces that lead to shrinkage are described, and topics such as environment and application, innovative materials, stress relief, moisture gradients, and computational tools are discussed. AASHTO R 101-22 currently recommends a few key approaches to reducing the potential for shrinkage cracking: (1) limit the paste content of the mixture, (2) specify unrestrained shrinkage limits, and (3) specify a material’s resistance to shrinkage cracking using the restrained ring or restrained dual ring test. Other approaches to reduce shrinkage cracking include the use of reduced paste volume, internal curing and shrinkage-reducing admixtures]]></description>
      <pubDate>Mon, 26 Sep 2022 09:12:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2019533</guid>
    </item>
    <item>
      <title>Performance of High Strength/High Ductility Concrete</title>
      <link>https://trid.trb.org/View/1996366</link>
      <description><![CDATA[Over the past two decades, successful attempts were made to produce field concrete with compressive strength surpassing 100 MPa. Meanwhile, other attempts succeeded in producing engineered cementitious composites (ECC) of relatively higher ductility. There is still a need to produce concrete that possessed both high strength coupled with relatively high ductility. This work aims at producing High Strength/ High Ductility Concrete (HSHDC) using materials from different sources and compare them to a conventionally produced concrete. Three types of cement, two oil well cement and one ordinary Portland cement, were used together with un-densified silica fume. Polypropylene and polyethylene fibers were incorporated at volume fractions. The experimental work covered a set of tests to obtain the material properties. Several tests were done to evaluate the strength, ductility, toughness and durability of these concrete mixes. Results suggest that most of the produced mixes achieved the desired qualities, which are having strength above 50MPa and at the same time possessing high ductility. The use of oil well cement with addition of fibers yielded the best performing HSHDC. The use of latex showed promising results in some of the properties but it yielded lower toughness.]]></description>
      <pubDate>Thu, 15 Sep 2022 16:53:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1996366</guid>
    </item>
    <item>
      <title>Investigation of Poor Compressive Strength and Performance of A45 Structural Concrete Mixes</title>
      <link>https://trid.trb.org/View/2021851</link>
      <description><![CDATA[In the last few years, a higher than usual number of concrete mixes with below specification compressive strengths have been observed by SDDOT. The 2020 and 2021 construction seasons saw dramatic increases in instances of failing strengths, particularly among A45 (4500 psi) structural concrete mixes. Failures missing the 4500-psi requirement by over 500 psi, which under specification, fall under “remove and replace” criteria, have become more common. All these failing mixes, on top of their negative impacts on concrete performance and project costs, have introduced increased risk for SDDOT, contractors, and concrete producers in future projects. Contractors and producers have reported that maintaining and achieving quality concrete performance has become increasingly difficult due to the prescriptive nature of the current A45 specification. The exact cause of these instances of low strength and poor performance is currently unknown. It could be the result of materials issues related to the cement, fly ash, admixtures, aggregates, or even incompatibility between some of these materials. Current mix designs could be outdated and may not reflect the materials used in practice. Outside of the mix design, the batching, delivery, placement, and curing methods currently specified could also be contributing to the low strengths observed. Testing procedures and handling of cylinders also impact strength development. Without investigating the cause of these low strengths and reducing the rate at which they occur, concrete mixes used by SDDOT will continue to have these costly problems. 
Objectives are as follows: 
(1)	Determine the factors contributing to the significant increase in instances of below-specification strength A45 structural concrete observed in recent construction years.
(2)	Recommend changes to current practice (handling, placement, testing, mix design) to reduce future instances of below-specification strength A45 structural concrete following placement in the field.
 ]]></description>
      <pubDate>Mon, 12 Sep 2022 17:21:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2021851</guid>
    </item>
    <item>
      <title>Evaluating Alkali-Silica Reactivity of Aggregates Using the New Miniature Concrete Prism Test and Other Standard Test Methods</title>
      <link>https://trid.trb.org/View/1956192</link>
      <description><![CDATA[The alkali-silica reaction (ASR) has been recognized as a major distress in concrete for nearly a century. In the US, ASR is a major cause of the deterioration of highway concrete structures (i.e., bridges and pavements). A research study was recently undertaken in the state of Idaho to evaluate the advantages associated with implementing the miniature concrete prism test (MCPT) from current standards for various reactive aggregates. A total of 11 different aggregate materials (both coarse and fine fractions), including a nonreactive reference aggregate, were collected from various sources and tested using the 56-days MCPT as well as the commonly used accelerated mortar bar test (AMBT). In addition, selected aggregate samples were tested using the 1-year long concrete prism test (CPT) and the 6-month accelerated concrete prism test (ACPT). The results demonstrated that the 56-day MCPT method resulted in higher percent expansion compared with the 14-day AMBT and 1-year CPT methods for the fine fractions of the test aggregates. The coarse fractions of the test aggregates, on the other hand, exhibited a lower percent expansion during the 56-day MCPT compared with the 14-day AMBT. Overall, the MCPT test results were found to correlate well with the 14-day AMBT and 1-year CPT test results. In addition, the 6-month ACPT method showed similar results to the ones of the 1-year CPT method, with high correlation between both methods. Recommendations were made based on the findings from this study to facilitate the implementation of the MCPT into practice by state and local highway agencies for better assessment of the ASR potential of aggregates.]]></description>
      <pubDate>Mon, 27 Jun 2022 17:16:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1956192</guid>
    </item>
    <item>
      <title>Development and MASH TL-4 evaluation of TXDOT large-scupper median barrier</title>
      <link>https://trid.trb.org/View/1957116</link>
      <description><![CDATA[Concrete median barriers are installed to prevent cross-median accidents by preventing passenger vehicles from penetrating another and to keep trucks from driving into oncoming traffic. Solid variate barriers are used on high speed roadways and highways with dense traffic to provide containment of vehicles in directional lanes and also to reduce maintenance and repair of roads. Solid concrete median barriers in flood-prone areas can provide dams for floodwaters as evidenced in hurricane and severe storm conditions and raise the level of floodwaters and cause significant damage to roads. A solution to this problem in flood areas that is in compliance with the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH Test Level 4 (TL-4) is needed. This article details the development of a MASH TL-4 large-scupper median barrier by the Texas A&M Transportation Institute (TTI) with the Texas Department of Transportation (TxDOT).]]></description>
      <pubDate>Wed, 25 May 2022 09:40:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1957116</guid>
    </item>
    <item>
      <title>Research on Impact Factors of Workability of Roller Compacted Concrete Based on Modified Vebe Test</title>
      <link>https://trid.trb.org/View/1919353</link>
      <description><![CDATA[To obtain the optimum workability of roller compacted concrete (RCC), it is necessary to fully consider the degree of influence of each component of RCC. In this research, the influence of water-cement ratio, the content of cement slurry, the content of mortar, the sand ratio, the particle size of maximum aggregate, and the content of mineral powder on the workability of RCC was studied by modified Vebe test. The results showed that the Vebe consistency decreased with the increase of water-cement ratio. The recommended range of cement slurry surplus parameter was 1.1~1.4; the recommended range of cement mortar surplus parameter was 1.2~1.6; mixing the fly ash and silica fume into RCC is beneficial to its workability, but the content of fly ash could not exceed 20 %, and the optimum value of the content of silica fume was between 5 and 7.5 %; and the sand ratio has a significant effect on RCC, and there is an optimal sand ratio just like ordinary concrete, which is 34 % in this study.]]></description>
      <pubDate>Mon, 28 Mar 2022 10:27:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1919353</guid>
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