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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>
    <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>Comparing Resistivity and Conductivity in Metal Culverts</title>
      <link>https://trid.trb.org/View/2643079</link>
      <description><![CDATA[Before installing an underground metal culvert, certain soil characteristics need to be measured to  calculate its expected service life. The service life of an underground culvert is a function of the expected  amount of corrosion based on the soil, the type of culvert used, and water conditions. The New Mexico  Department of Transportation (NMDOT) uses three different soil properties to estimate culvert service  life: (1) the soil’s electrical conductivity (EC); (2) pH level; and (3) gypsum content. Soil EC measures  how easily an electric charge can be passed (conducted)through the soil, with the soil’s moisture content  having a large effect. Soils with pH lower than 5.5 and greater than 7.3 have been shown to have adverse  effects on galvanized coated (zinc coating)steel culverts. Lastly, knowing the amount of gypsum (CaSO4  2H2O) in the soil is important because gypsum (specifically, the sulfates within the gypsum, SO42)  readily corrodes zinc and steel. All three of these soil properties’ corrosive potential is further increased  with higher moisture content in the soil. With culverts’ typical proximity to water, accurate accounting  of these soil parameters is crucial in the determination of the type of culvert to be used, based on a  minimum of 50 years of service life.  This project used in-situ and laboratory measurements of soil conductivity and resistivity to determine  the compatibility of the Natural Resource Conservation Service (NRCS) Soils Maps for metal corrosion  potential versus the 2018 NMDOT Culvert Resistant Spreadsheet (CRS).]]></description>
      <pubDate>Mon, 12 Jan 2026 09:13:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643079</guid>
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    <item>
      <title>Quantitative Evaluation of the Remediation Process in Engineering Rock Fractures Using Electrical-resistivity Method</title>
      <link>https://trid.trb.org/View/2635252</link>
      <description><![CDATA[This study proposed a non-invasive electrical resistivity method to track the fracture remediation process driven by microbially induced calcium carbonate precipitation. A seven-cycle grouting experiment was conducted on a rough-walled single fracture with an average aperture of 1.02 mm. Resistivity was measured with a four-electrode method, and water pressure and precipitate thickness provided independent validation. The results indicated a non-uniform resistivity distribution across the fracture, with the resistivity increment decreasing from 26.6 Ω·m to 2.4 Ω·m along the flow path. The calcium carbonate precipitation and water pressure also exhibited an analogous spatial distribution pattern. The overall negative relationship between the electrical resistivity and the fracture aperture was well fitted by the power-law function with an R² value greater than 0.99. Incorporating pressure data into the established resistivity-aperture empirical relation yielded a reduction in absolute aperture estimation error, decreasing it from 0.103 mm to 0.075 mm. This study provided a promising non-invasive approach for real-time monitoring of the fracture remediation process, with potential applications in evaluating sealing efficiency in deep underground engineering.]]></description>
      <pubDate>Wed, 31 Dec 2025 10:56:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635252</guid>
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    <item>
      <title>Integrated geotechnical and electrical resistivity approaches for investigating rainfall-induced slope failure in a mountainous highway embankment</title>
      <link>https://trid.trb.org/View/2601823</link>
      <description><![CDATA[A rainfall-induced slope failure occurred in October 2022 along Highway No. 1088 in northern Thailand. To investigate the failure mechanism, an integrated approach combining geotechnical, geological, and geophysical methods was employed. Borehole drilling and laboratory testing were conducted to evaluate soil stratigraphy, strength parameters, and water content, while 2D electrical resistivity imaging (ERI) was used to identify subsurface profiles and failure surfaces over a large area. The failure surface was inferred at depths between 3.00–6.45 m based on borehole data, characterized by low N₆₀-values and water contents exceeding the plastic limits. The 2D ERI results delineated a low-resistivity zone (10–20 Ωm) at depths between 6.00–9.00 m, indicating a preferentially saturated and mechanically weak layer consistent with the failure surface. Integration of the 2D ERI profiles revealed a northwest-oriented slope movement direction, aligning with field observations of fracture patterns and regional fault orientation. Geological investigation of outcrops supported the identification of semi-consolidated interbedded clay and gravel layers with high weathering susceptibility. The study demonstrates that the integration of resistivity imaging with conventional geotechnical investigations provides a robust framework for assessing failure surfaces and slope movement in complex geomaterials. These findings are essential for slope stability analysis, early-warning system design, and the development of targeted countermeasures in rainfall-prone mountainous regions.]]></description>
      <pubDate>Tue, 11 Nov 2025 09:23:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2601823</guid>
    </item>
    <item>
      <title>Long-Term Corrosion Monitoring in Mechanically Stabilized Earth (MSE) Walls</title>
      <link>https://trid.trb.org/View/2601510</link>
      <description><![CDATA[This research is a continuation of K-TRAN: KSU-19-5. Mechanically stabilized earth (MSE) walls with metallic reinforcement are widely used as a cost-effective means of earth retention. Metallic reinforcement, which is susceptible to corrosion, is typically sized for a 75-year design life after allowing for a standard rate of corrosion. The Kansas Department of Transportation (KDOT) has many walls that have completed more than one-third of their design life. The previous study measured backfill corrosion conditions for 12 MSE walls selected by KDOT. The walls were surveyed by cutting through the wall face, sampling the backfill, and inspecting reinforcing strip conditions. The current study utilized a similar approach to validate a new field method for monitoring backfill conditions and to establish the current conditions of MSE walls selected by KDOT. In this study, 18 MSE walls were selected, six of which were surveyed in the previous study. In general, the field resistivity method and the physical sampling method consistently identified backfills with poor conditions. The results support the use of a modified four-electrode electrical resistivity measurement to identify backfill with high in situ moisture, high percent fines, and high levels of chlorides, which all lead to high corrosivity. Furthermore, this study documents the current conditions of the 18 walls, including unique photos of exposed reinforcement. Results from the physical testing of backfills showed that the finest fraction of the backfill (D10) was strongly correlated with low resistivity values, particularly for sand backfills. High chloride concentrations were also measured in the samples with the lowest resistivity. These results support the current recommendation that the percentage of fines (material smaller than the #200 sieve) be limited to a maximum of 5% and encourage the consideration of an additional specification that the percentage passing the #100 sieve be limited to 10%.]]></description>
      <pubDate>Fri, 19 Sep 2025 16:58:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2601510</guid>
    </item>
    <item>
      <title>Answers to Your Resistivity Questions and Helpful Findings to Develop a Robust Resistivity Specification</title>
      <link>https://trid.trb.org/View/2382091</link>
      <description><![CDATA[Many states are currently in the process of evaluating the use of surface resistivity (SR) or bulk resistivity (BR) tests to assess permeability of concrete in lieu of the standard test method for electrical indication of concrete’s ability to resist chloride ion penetration (AASHTO T 277 and ASTM C1202) which is commonly referred to as the rapid chloride permeability test (RCPT). A few states, such as Louisiana and Maine, implemented resistivity testing in their specifications many years ago. As with any test method implementation, it is important to learn from data generated and experience gained to further refine the specifications in respect of both testing protocols and the specification limits. In this paper, the Federal Highway Administration’s Mobile Concrete Technology Center SR and BR data from 30 field projects in 25 states is analyzed to provide information that could be helpful to agencies as they specify or improve their specifications with respect to resistivity testing. This paper attempts to answer questions related to 1) change in resistivity testing results with age, 2) range and variability of resistivity data from mainline paving mixtures, 3) comparison of test results between SR and BR data, 4) comparison of resistivity data gathered with equipment from various vendors, and 5) use of 28 versus 56?day data.]]></description>
      <pubDate>Mon, 27 May 2024 10:10:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2382091</guid>
    </item>
    <item>
      <title>Considerations for Scalability of Alkali Concentrated Conditioning Solution</title>
      <link>https://trid.trb.org/View/2359120</link>
      <description><![CDATA[Artificial pore solution (APS) is a conditioning solution for use in determining formation factor in accordance with the American Association of State Highway and Transportation Officials (AASHTO) T 402. The use of a highly alkaline solution, such as APS, has precedence in the construction industry (e.g., for assessment of aggregate susceptibility to alkali-silica reaction). However, those applications use the solution as part of a prequalification process, not for construction quality assurance or quality control (QA/QC) programs. This TechBrief highlights the significant challenges associated with using APS in a QA/QC application. The goal of this document is to inform selection of repeatable, responsible, and relevant QA/QC tests for concrete materials. Formation factor can be used to predict service life but may not be practical to use for construction QA/QC. Meanwhile, resistivity may be more appropriate for construction QA/QC. This document discusses the considerations necessary for scaling APS from small numbers of bucket-sized volume solutions, which have been demonstrated in the research environment, to tank-sized volumes or large numbers of bucket-sized solutions necessary for larger scale QA/QC operations during construction operations.]]></description>
      <pubDate>Thu, 11 Apr 2024 13:23:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2359120</guid>
    </item>
    <item>
      <title>NETL Plastic Pipes Project - Final Report</title>
      <link>https://trid.trb.org/View/2329740</link>
      <description><![CDATA[Plastic or composite pipelines have been the bane of the utility locating industry because conduits are neither conductive nor magnetic, which are the properties traditionally used to locate buried utilities. Ground penetrating radar (GPR) is an effective geophysical tool for locating plastic/composite pipeline where the resistive cover allows for adequate penetration of radar energy. However, GPR cannot be used in areas where the soil cover is conductive due to significant clay and/or salt content. This study takes a comprehensive look at near-surface geophysical methods that potentially are useful for locating buried plastic/composite pipelines, either singly or in combination with other geophysical methods. Specifically, this modeling study uses computational numerical methods to forward model the response of GPR, resistivity, seismic, and gravity gradiometry methods to plastic/composite pipelines for various scenarios including: (1) pipe diameters ranging between 2 in. to 12 in.; (2) burial depths ranging between 3 ft to 4 ft; (3) various degrees in contrast in physical properties (i.e., permittivity, elasticity, electrical resistivity, density); and (4) various experimental acquisition choices (e.g., GPR radar frequencies, seismic source frequency, electrode spacing).]]></description>
      <pubDate>Mon, 12 Feb 2024 10:31:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/2329740</guid>
    </item>
    <item>
      <title>Deep Learning Joint Inversion of Electrical Data for Ahead-Prospecting in Tunneling</title>
      <link>https://trid.trb.org/View/2145535</link>
      <description><![CDATA[Water inrush has become one of the bottlenecks restricting tunnel construction. Among various advanced forecasting techniques, the direct current method is more cost-effective and sensitive to water-bearing structures. It has been widely used in exploring water inrush disasters in practical engineering. Although traditional resistivity linear inversion methods are reasonably practical, they usually suffer from volume effects and cannot accurately locate the location and morphology of water-bearing bodies. Therefore, nonlinear techniques such as deep learning have recently become popular to directly approximate the inversion function by learning the mapping of apparent resistivity data to the geoelectric model. This work presents a novel deep learning-based electrical approach that combines resistivity and polarizability to estimate water-bearing location and morphology. Specifically, the authors design an encoder-decoder network. A shared encoder extracts features from the input data, two encoders output resistivity, and polarizability models, respectively, and fine-tuned collinear regularization for both outputs reduces solutions’ multiplicity. Compared with traditional linear inversion methods and independent parameter inversion, the authors' proposed joint inversion method shows superiority in locating and delineating anomalous bodies.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:49:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2145535</guid>
    </item>
    <item>
      <title>PEM: Influence of Curing Regimes on Formation Factor</title>
      <link>https://trid.trb.org/View/2077942</link>
      <description><![CDATA[This study will investigate new techniques for quantifying curing effectiveness of concrete materials. The study focuses on the reduction of early age shrinkage cracking.]]></description>
      <pubDate>Tue, 06 Dec 2022 09:48:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2077942</guid>
    </item>
    <item>
      <title>Feasibility Study on Geophysical Methods to Estimate Geotechnical Properties in Louisiana</title>
      <link>https://trid.trb.org/View/2039837</link>
      <description><![CDATA[Subsurface investigations currently rely on conventional soil borings with the aid of cone penetrometer test (CPT) soundings. However, these geotechnical explorations can be expensive and information is not provided between boreholes. Geophysical methods can aid in providing some information between the boreholes at a lower cost for the Louisiana Department of Transportation and Development (DOTD). These cost-effective geophysical surveys include other advantages, such as site accessibility, portability, operator safety, shorter project delivery times, and reduced construction delays. This study evaluated a series of available geophysical methods. A survey determined the preferred applications that Louisiana is interested in incorporating. Researchers further refined this list to include test methods most suitable for implementation within the Department. Analysis included applicability, advantages/disadvantages, and current test methods utilized in-house at other state DOTs. Researchers recommend more detailed field research directed toward implementing the following geophysical methods: electrical resistivity, seismic refraction, and cross-hole tomography.]]></description>
      <pubDate>Tue, 25 Oct 2022 09:21:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2039837</guid>
    </item>
    <item>
      <title>Imaging Ahead of Tunnel Boring Machine with DC Resistivity</title>
      <link>https://trid.trb.org/View/1881956</link>
      <description><![CDATA[Tunnel boring machines (TBMs) are often used for underground tunneling and construction projects. However, there are dangers and risks during underground construction from unknown hazards ahead of tunneling operations, which may result in surface settlement and machine damage. Geophysical methods have the potential to improve tunneling projects by imaging the subsurface ahead of a TBM. In particular, direct current (DC) resistivity is an attractive option because the electrical conductivities of hazards such as soils, rocks, pipes, and other anomalous features vary over several orders of magnitude. The resistivity method is well understood in the context of surface and borehole geophysics, but it is seldom applied in underground construction and tunneling. Furthermore, the high conductivity of the TBM itself and the reduced number and available positions of electrodes that can be used on the cutterhead present challenges to the method. In this study, DC resistivity data are collected with model TBMs in laboratory scale environments and compared with numerical simulations for the purpose of better understanding the potential value to tunneling operations. Furthermore, the authors  perform tests of various inversion algorithms to determine if reliable geophysical images can be produced in such a challenging environment. Overall, the experimental and numerical results show that DC resistivity is capable of detecting and imaging hazards in front of a TBM.]]></description>
      <pubDate>Wed, 10 Nov 2021 13:54:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1881956</guid>
    </item>
    <item>
      <title>The Use of Resistivity Testing for Quality Control of Concrete Mixtures</title>
      <link>https://trid.trb.org/View/1866539</link>
      <description><![CDATA[This study proposes a new quality control and compliance method for concrete mixture design using standard surface resistivity testing. This method helps in determining key mixture parameters such as fly ash content and w/cm of placed concrete. Based on the gain in resistivity over time, it was found that the slope of the surface resistivity versus time curve could be used to differentiate fly ash content. And, the resistivity value obtained at a sample age of 14 and 28 days could be used for identifying the water-to-cementitious material ratio of a concrete mixture containing no fly ash and containing up to 20% fly ash. Several other parameters such as, aggregate type and admixture addition are also evaluated for their effect on the outcome of a resistivity test. The proposed resistivity method could be used as a means for quality acceptance of mixture design during the construction stage. Three methodologies (Procedure A, B and C) for OkDOT Classes A and AA concrete mixtures are developed and trialed as part of a field study. In addition, the influence of laboratory ambient temperature and curing temperature was also investigated. It was found that if resistivity testing is performed in a standard temperature-controlled environment, resistivity variances are negligible. Finally, with all quality control material testing, an alternative test method is investigated in the event the primary lab specimen fails to meet the specification. The secondary compliance testing method targets the adequacy of concrete constructed onsite. In the end, the outcomes of the project can aid a DOT in devising a strategy for implementation of the resistivity method. The new tool enables control of placed concrete with respect to the approved mixture design.]]></description>
      <pubDate>Mon, 27 Sep 2021 09:45:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1866539</guid>
    </item>
    <item>
      <title>Measuring Corrosion Conditions in Mechanically Stabilized Earth Walls</title>
      <link>https://trid.trb.org/View/1875166</link>
      <description><![CDATA[KDOT extensively utilizes mechanically stabilized earth (MSE) walls, typically with coarse aggregate backfill. Previous projects K-TRAN: KSU-15-6 and K-TRAN: KU-15-5 tested the aggregate material from MSE walls under construction. KU identified that several of the clean aggregate samples contained some fines, likely from crushing of the aggregate, and two of the walls contained over 10% fines. Aggregate backfill is specified because it allows for free drainage, limiting the pore water pressure buildup behind the wall. There is the potential for these fines to migrate towards the base of the wall over time. This migration of fines would not only increase the potential for water retention, but it would also increase the localized corrosion potential of the backfill. This joint project measured the backfill corrosion conditions of 12 MSE walls selected by KDOT. Walls were surveyed using a variety of non-destructive resistivity arrays and by cutting through the wall face, sampling the backfill, and inspecting reinforcing strap conditions. Multiple walls with potentially corrosive backfills (low resistivity) were identified, and several walls had reinforcement with visible corrosion in progress. The resistivity survey method and the physical sampling method were generally consistent in identifying backfills with low resistivity. The results support the potential of using a modified four-electrode electrical resistivity measurement to identify corrosive environments in MSE walls. If used by KDOT, this will improve KDOT’s geotechnical asset management of MSE walls. Results from the physical testing of backfills showed that the finest fraction of the backfill (D10) was strongly correlated with low resistivity values, particularly with the sand backfills. High chloride concentrations were also measured in the three samples with the lowest resistivity. These results support the current recommendation that the percentage of fines (material smaller than the #200 sieve) be limited to a maximum of 5%, and encourages the consideration of an additional specification that the percentage passing the #100 sieve be limited to 10%.]]></description>
      <pubDate>Mon, 27 Sep 2021 09:45:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1875166</guid>
    </item>
    <item>
      <title>Rating Concrete Permeability Based on Resistivity Measurements</title>
      <link>https://trid.trb.org/View/1877221</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Thu, 09 Sep 2021 10:01:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1877221</guid>
    </item>
    <item>
      <title>Electrical and Mechanical Properties of Self-Sensing SHCC</title>
      <link>https://trid.trb.org/View/1756626</link>
      <description><![CDATA[A multifunctional material can be used to protect and monitor the degraded concrete infrastructure, providing a self-sensing capacity that is designed to specifically diagnose cracking. Strain-hardening cementitious composites (SHCC) presents superb tensile ductility and pseudo strain-hardening property. In this study, the electrical and mechanical properties of SHCC incorporating carbon black (CB) nanoparticles and air entraining agent (AEA) are examined. The electrical response of SHCC, HFA-SHCC (high fly ash SHCC), and CB-SHCC under direct tension is investigated using the four-point probe test. The results show that the bulk resistivity of all specimens increased with the crack propagation, and the increase ratio in the inelastic phase is much higher than that in the elastic phase. Furthermore, CB-SHCC specimens showed the most sensitive response to first cracking, which can be potentially utilized to detect micro cracking by means of variation in resistivity.]]></description>
      <pubDate>Thu, 25 Mar 2021 09:35:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1756626</guid>
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