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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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    <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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Study on the Preparation and Mechanical Properties of Ultra-Early Strength Ultra-High-Performance Concrete (UES-UHPC)</title>
      <link>https://trid.trb.org/View/2672681</link>
      <description><![CDATA[To address the low early-age strength of ultra-high-performance concrete (UHPC) under standard curing, this study develops an ultra-early-strength (UES)-UHPC. The cementitious materials system of the proposed UES-UHPC is a composite of sulfoaluminate cement (SAC) and ordinary Portland cement (OPC). Calcium oxide (CaO) is incorporated to boost early-age strength. The chemical admixtures primarily include an early-strength accelerator, a retarder, and an early-strength superplasticizer. To enhance the toughness of UES-UHPC, steel fibers (SF) were incorporated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to characterize hydration products and microstructures. The acoustic emission (AE) technique is applied during early-age flexural tests to track internal damage evolution. In addition, the flowability of the fresh UES-UHPC mixture and the mechanical properties of UES-UHPC were measured. This study focuses on the synergistic toughening and ultra-early-age compressive-strength enhancement afforded by the SAC–OPC–CaO–SF system. Results show that the proposed UES-UHPC achieves a compressive strength of up to 96?MPa at 2?h and 179?MPa at 28 days. The system rapidly forms an ettringite (AFt) and calcium–alumino–silicate–hydrate (C–A–S–H) skeleton together with a densified interfacial transition zone (ITZ), which in turn enables SF to bridge cracks effectively. Consequently, under ambient curing the system concurrently delivers ultra-early-age strength and high toughness. Moreover, a higher SF content leads to a larger proportion of shear-dominated cracks, especially near failure.]]></description>
      <pubDate>Sun, 22 Feb 2026 14:57:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672681</guid>
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    <item>
      <title>Effect of urea on the thixotropic behavior of mixtures containing calcium aluminate cement and Portland cement</title>
      <link>https://trid.trb.org/View/2643528</link>
      <description><![CDATA[This study investigates influence of urea utilization on the rheological and thixotropic properties of Portland and calcium aluminate cementitious system. In each cementitious system, a total of eight different paste mixtures were prepared with 2.5%, 5% and 10% replacement of cement weight with urea. Thixotropic behavior was evaluated using the step change and the loop methods. The use of urea in cementitious systems, independent of the type of cement, was found to result in a decrease in dynamic shear stress and viscosity values, in other words, an increase in flow performance. The addition of urea was observed to increase the formation of thixotropic structure, and this effect is more pronounced in Portland cement mixtures. The Herschel–Bulkley model is more consistent with the rheological data obtained in Portland cement mixtures. In Portland cement mixtures, the values of structural build-up are observed to be higher compared to the values of structural breakdown, while in calcium aluminate cement mixtures, the opposite has been observed. The viscosity after rest value decreased by 95% with the addition of 10% urea to the mixture containing Portland cement, and this value decreased by 76% with the addition of 10% urea to the mixture containing calcium alumina.]]></description>
      <pubDate>Sat, 07 Feb 2026 16:21:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643528</guid>
    </item>
    <item>
      <title>Rapid hardening high performance concrete (RHHPC) for bridge expansion joints: From material properties to interfacial shear performance</title>
      <link>https://trid.trb.org/View/2481703</link>
      <description><![CDATA[To accelerate the replacement of damaged bridge expansion joints and minimize the impact on traffic, employing rapid hardening high performance concrete (RHHPC) as infilling materials is one competitive alternative. To this end, five groups of concrete considering different contents of sulfate aluminate cement (SAC) and steel fiber were designed to obtain the optimal RHHPC mixtures. Subsequently, a series of push-off tests were conducted to investigate the interfacial shear performance between RHHPC and normal concrete (NC), with the variables of interfacial treatment, shear reinforcement ratio, concrete strength, and curing age. The test results demonstrated that increasing the steel fiber contents enhanced both the compressive and tensile strength, but reduced the slump of fresh RHHPC. The increase in the SAC contents resulted in a significant decrease in setting time. The push-off tests failed by interfacial shear failure, accompanied with significant concrete cracking, spalling, or splitting. Both the ultimate load and residual load improved as the interfacial roughness, shear reinforcement ratio, concrete strength, and curing age increased. Based on the experimental results, a modified model considering the contributions of concrete strength, shear reinforcement clamping stress, and concrete cohesion was proposed to predict the interfacial shear capacity between RHHPC and NC.]]></description>
      <pubDate>Tue, 18 Feb 2025 10:56:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2481703</guid>
    </item>
    <item>
      <title>Investigating the Use of Rapid Setting Hydraulic Cements (RSHCs) for Structural Applications</title>
      <link>https://trid.trb.org/View/2398606</link>
      <description><![CDATA[Construction and replacement of infrastructure assets results in costly road closures. Rapid setting hydraulic cements (RSHCs), like calcium sulfoaluminate (CSA) cement and calcium aluminate cement (CAC), can dramatically reduce the time needed for construction. These cements are beginning to gain the attention of various stakeholders in the cement and concrete industry owing to their remarkable properties and notably lower carbon footprint compared to ordinary portland cement (OPC) and other traditional infrastructure materials. Currently, the use of CSA and CAC cement is often limited to rapid repair applications and other special applications where their exclusive qualities are required. The primary goal of the work outlined in this report is to demonstrate the use of RSHCs for use in structural applications. This study showed that RSHC concrete can be designed to meet structural class specifications in terms of fresh (i.e., workability and working time) and hardened properties (early- and/or later-age strength). All RHSCs mixtures, when evaluated under accelerated carbonation, showed significantly lower carbonation resistance when compared to OPC at an equivalent w/c ratio and curing age. When the RHSCs mixtures were evaluated for natural concrete carbonation outdoors in Texas, the performance of RSHCs was dependent on exposure type. Samples placed outdoors and exposed to precipitation had a markedly higher resistance to carbonation compared to samples placed in sheltered conditions. Regarding corrosion potential, all RSHC mixtures, with the exception of a few CSA cement types corrosion potential appears to be comparable to OPC after 3 years of exposure. Bulk-chloride diffusion test showed that these cements had much lower chloride binding capacity compared to CAC and OPC systems. Despite these results more information is still needed to fully understand the performance of RSHC in various durability-related distresses. In particular, more work is needed to understand their potential implication in chloride- and carbonation-induced corrosion. While many RSHCs showed potential in being capable of meeting durability performance, time is still needed to discern their behavior in these conditions, especially under long-term service conditions (i.e., cracked and carbonated RSHC concrete). Nonetheless, opportunities may arise for some RSHCs to be used in targeted structural applications that can achieve durability requirements.]]></description>
      <pubDate>Mon, 08 Jul 2024 09:08:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2398606</guid>
    </item>
    <item>
      <title>The role of tricalcium aluminate and gypsum dehydration level in cement for effective air entrainment of concrete</title>
      <link>https://trid.trb.org/View/2325399</link>
      <description><![CDATA[In this paper, the role of tricalcium aluminate (C3A) and gypsum dehydration level in the air-entraining mechanism in concrete was studied. A higher-performance air system was achieved when anionic surfactant was used, C3A content was higher and gypsum dehydration didn’t occur. Adsorption on cement particles dominates the air-entraining mechanism when anionic admixture is used. Anionic surfactant performs higher quality air microstructure than cationic, despite much lower surface tension reduction. Thus, the adsorption of admixture had a major role in the effective air-entraining mechanism process. This effect has significant implications on the selection of the best-suited surfactants, cement optimum composition and the cement production procedure for the highest frost resistance concretes used for roads and bridges.]]></description>
      <pubDate>Tue, 30 Jan 2024 09:25:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2325399</guid>
    </item>
    <item>
      <title>Suitability of CPC-18 and Carbonation of Specialty Cementitious Systems</title>
      <link>https://trid.trb.org/View/1985121</link>
      <description><![CDATA[Carbonation of concrete systems can result in corrosion of the steel reinforcement. The International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM) Concrete Permanent Committee-18 (CPC-18) test method is commonly used to determine the carbonation depth of ordinary portland cement (OPC) systems. However, the standard does not clearly state whether this test is appropriate for specialty cementitious systems such as calcium aluminate cement (CAC) and calcium sulfoaluminate cement (CSA). Thermogravimetric analysis (TGA), on the other hand, is a proven test method to determine the carbonation front of all cementitious systems. This study assesses the reliability of CPC-18 by comparing CPC-18 test results with TGA results for carbonated OPC, CAC, and CSA systems. Results indicate that CAC and CSA systems carbonate faster than OPC systems, and the CPC-18 method can be used for testing the carbonation depth of CSA systems. However, the CPC-18 test method produces a less distinct color in CAC, which could lead to higher variability in results.]]></description>
      <pubDate>Mon, 29 Aug 2022 09:27:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1985121</guid>
    </item>
    <item>
      <title>Alkali-silica reaction in calcium aluminate cement mortars induced by deicing salts solutions</title>
      <link>https://trid.trb.org/View/1991580</link>
      <description><![CDATA[Calcium aluminate cement (CAC) mortars and concrete may be used as high-performance repairing materials for pavement restoration in airfields and roads. During recent years alkali-silica reaction (ASR) was reported in Portland cement concrete subjected to the action of organic deicers. Present paper reports the results of the investigation on the influence of organic and inorganic alkali deicers on ASR potential in CAC mortars containing fused silica as model reactive aggregate. It was shown for the first time, that concentrated solutions of sodium and potassium acetates, as well as sodium chloride, can cause ASR in CAC mortars. Sodium and potassium acetate resulted in much larger expansions comparing to sodium chloride and sodium hydroxide solutions used as a reference. Differences in alkali-silica gel were found depending on the solution which samples were soaked in. It was shown that ASR could proceed in a system without calcium hydroxide and an external source of hydroxyl ions.]]></description>
      <pubDate>Mon, 01 Aug 2022 17:20:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1991580</guid>
    </item>
    <item>
      <title>Long-term effect of accelerator content on flexural toughness of steel fiber reinforced shotcrete for tunnel construction</title>
      <link>https://trid.trb.org/View/1880549</link>
      <description><![CDATA[Shotcrete is widely used in underground and tunnelling applications due to their superior flexural properties and impact resistance. There is a higher need in improving these properties by adding various admixtures and fibre reinforcements to achieve superior performance to accomplish faster turnout in tunnelling constructions. In this study, the effect of three accelerators on the long-term flexural performance of steel-fiber reinforced shotcrete were investigated. The types of accelerators used were aluminate, cement mineral, and alkali-free accelerators, whose effects on the flextural properties were investigated over the periods of 1, 3, 6, 12, and 24 months. The flexural toughness was first estimated in accordance with JSCE SF-04, where up to span/150 deflection area under the load-deflection curve was used for calculating the flexural toughness. Whereas ASTM C1018-97 was used to evaluate the first-crack and post-peak load toughness behavior with three specified points for better understanding the flexural behavior of all mixtures. Moreover, it is important to use alkali-free accelerators in terms of both the long-term performance of the tunnels and the safety of the workers. The long-term performances of the specimens showed by the compressive strength and flexural strength were comparable. Finally, according to the long-term effectiveness and performance, the best mix design for the tunnel construction sites is also proposed.]]></description>
      <pubDate>Mon, 24 Jan 2022 17:27:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1880549</guid>
    </item>
    <item>
      <title>Using CSA Cement for Novel Waterway Repair Materials</title>
      <link>https://trid.trb.org/View/1897286</link>
      <description><![CDATA[Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for necessary maintenance activities which can often lead to closures. These structures are not easy to detour and often require dewatering before repairs can be made. Closures can cause delays and business-related losses which can have a large economic effect. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising repair material due to its properties. BCSA cement is a fast-setting hydraulic cement capable of reaching compressive strengths greater than 4000 psi (27.6 MPa) in less than 2 hours. BCSA also has low shrinkage and good long-term strengths. This research consisted of developing an optimal rapid-setting underwater repair mortar mixture design using BCSA cement. Properties such as compressive strength and workability were tested to select the best mix design. Additionally, soil-cements made with BCSA cement were compared to portland cement-based soil-cements. These soil cements have applications for the rapid repair of levees and earthen dams, but also for rapid soil stabilization. The results obtained proved that BCSA cement is a promising material for rapid underwater repairs and repairs of soil-based waterway structures.]]></description>
      <pubDate>Tue, 28 Dec 2021 09:30:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1897286</guid>
    </item>
    <item>
      <title>Using CSA Cement for Novel Waterway Repair Materials [supporting dataset]</title>
      <link>https://trid.trb.org/View/1897287</link>
      <description><![CDATA[Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for necessary maintenance activities which can often lead to closures. These structures are not easy to detour and often require dewatering before repairs can be made. Closures can cause delays and business-related losses which can have a large economic effect. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising repair material due to its properties. BCSA cement is a fast-setting hydraulic cement capable of reaching compressive strengths greater than 4000 psi (27.6 MPa) in less than 2 hours. BCSA also has low shrinkage and good long-term strengths. This research consisted of developing an optimal rapid-setting underwater repair mortar mixture design using BCSA cement. Properties such as compressive strength and workability were tested to select the best mix design. Additionally, soil-cements made with BCSA cement were compared to portland cement-based soil-cements. These soil cements have applications for the rapid repair of levees and earthen dams, but also for rapid soil stabilization. The results obtained proved that BCSA cement is a promising material for rapid underwater repairs and repairs of soil-based waterway structures.]]></description>
      <pubDate>Tue, 28 Dec 2021 09:30:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1897287</guid>
    </item>
    <item>
      <title>Pore size analyses of cement paste exposed to external sulfate attack and delayed ettringite formation</title>
      <link>https://trid.trb.org/View/1899480</link>
      <description><![CDATA[Experimental studies on cement paste exposed to external sulfate attack (ESA), delayed ettringite formation (DEF), and the coupling effect of both reactions are presented in this paper. The objective is to compare the degraded state of specimens, the length and mass variations, and the pore size distribution (PSD) obtained by mercury intrusion porosimetry (MIP) of cement paste submitted to these different exposure conditions. By comparing the PSD of specimens before and after the sulfate attacks, a global expansion mechanism is proposed : ettringite first precipitates in the biggest pores without inducing obvious expansion, and then penetrates into capillary and gel pores leading to an accelerated swelling. In addition, the coupling effect of ESA and DEF is found to be the most damaging expansion, which raises a high durability problem for cement-based materials.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:46:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899480</guid>
    </item>
    <item>
      <title>The revision of the French recommendations for the prevention of Delayed Ettringite formation</title>
      <link>https://trid.trb.org/View/1899446</link>
      <description><![CDATA[The expansive sulphate internal reaction of concrete due to Delayed Ettringite Formation (DEF) can damage concrete structures severely. DEF is defined as the formation of ettringite in a concrete after setting, and without any external sulphate supply, but with water supply. This phenomenon appears in concretes exposed to frequent humidity or contact to water, and subjected to a relatively high thermal treatment (> 65°C) or having reached equivalent temperatures for other reasons (massive cast-in-place concrete, concrete casting during summer, etc). The expansive process leads to macroscopic effects similar to those created by Alkali-Aggregate Reaction (AAR) and mainly consisting in material swelling, cracking and decreasing of the mechanical properties which may cause large structural disorders due to unexpected deformations and additional stresses in concrete and reinforcement. In the absence of effective and durable treatment methods to repair or rehabilitate the structures affected by DEF, IFSTTAR (former LCPC) published in 2007 the French recommendations for the prevention of disorders due to DEF; an English version was released in 2009. After ten years of application, the time has come to revise this guidance that will be published in 2017. After a recall of the previous recommendations, the paper is presenting the main evolutions of the document, and particularly the modifications introduced for the precautions, and the calculation of the estimated temperature inside concrete at construction.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:44:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899446</guid>
    </item>
    <item>
      <title>Locating ettringite due to DEF at the pore scale of cement paste by heat-based dissolution tests</title>
      <link>https://trid.trb.org/View/1899399</link>
      <description><![CDATA[An innovative experimental method, based on the thermal stability of ettringite, is proposed and implemented to dissolve the crystalline products formed during Delayed Ettringite Formation (DEF). The tests are designed to empty all the pores that are filled by ettringite during their formation. By characterising the porous structure before and after the heat-based dissolution test (HBDT) via Mercury Intrusion Porosimetry (MIP), it is proved that the pores filled by ettringite during DEF in the pore size range between 4 and 30?nm are emptied and that the pore size distribution (PSD) in this range is reversed, approaching the initial state (i.e. before the degradation induced by DEF). This observation helps to confirm the location of ettringite formed during DEF.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:42:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899399</guid>
    </item>
    <item>
      <title>From AAR to DEF: Numerical Modelling of Structures affected by expansive Reaction in Concrete</title>
      <link>https://trid.trb.org/View/1899285</link>
      <description><![CDATA[The recent detection in France of several scores of worrying Delayed-Ettringite For- mation (DEF) affected cases in major concrete structures urged the need for developing numerical models adapted to the specificities of DEF. Recently discovered and identified as a possibly single and major origin of disorders, DEF is not so largely studied as Alkali-Aggregate Reaction (AAR). However, it presents strong similarities with AAR: concrete is subjected to expansive chemical reactions which induce cracks, abnormal deformations, stiffness decrease. As a unique feature, early-age thermal history plays a crucial role in forthcoming DEF de- velopment. This contribution explains how a numerical tool for DEF-affected concrete was built based on a macro-scale model developed for AAR. The focus is put on the AAR-features used as a starting point, and on the specific model developed to take into account early-age history.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:36:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899285</guid>
    </item>
    <item>
      <title>DEF-pathology in Concrete supporting a lock-gate: use of numerical modelling to re-assess structural behaviour</title>
      <link>https://trid.trb.org/View/1899284</link>
      <description><![CDATA[Delayed ettringite formation (DEF) is a concrete pathology which may occur in structural parts submitted to high temperature during their casting, such as some massive elements cast in-situ. DEF consequences can lead to structural disorders (expansions, cracking, deterioration of mechanical properties), which modify and jeopardize structures serviceability and sometimes, safety. This communication deals with a concrete lock for which a large prestressed beam supporting the lower gate is affected by DEF for several years. First, the structure and its pathology are described. The global strategy of the study, mixing together documents analysis, laboratory tests on concrete samples and use of finite-element models is then presented. These numerical models have multiple purposes: assessing the early-age thermal history of the beam in order to confirm the origin of DEF; assessing the structural behaviour and its modification due to DEF, based on chemo-mechanical coupling models; mechanical interaction between the beam and the other parts of the lock. This modelling is performed to assess structural state at present time, as well as to predict its evolution in the future. Finally, conclusions drawn from the study are used to help structure owner in their planning of his maintenance policy.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:36:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899284</guid>
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