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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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Environmental controls and reaction pathways of coupled de-dolomitization and thaumasite formation</title>
      <link>https://trid.trb.org/View/1464230</link>
      <description><![CDATA[Deteriorated concrete and interstitial solutions (IS) were collected from Austrian tunnels to elucidate potential connections between de-dolomitization caused by coupled alkali carbonate reactions (ACR) and thaumasite form of sulfate attack (TSA). A conceptual reaction model for the portlandite–calcium silicate hydrate (CSH) phases–dolomite–calcium sulfate–calcite–brucite–thaumasite system was developed based on experimental data, hydrochemical modelling, IS chemistry and apparent concrete compositions. During the initial stage of sulfate attack, ettringite and gypsum formation weakened the concrete's microstructure and initiated ACR. Leaching of hydrated cement phases resulted in IS with a pH ~ 12-13, which promoted incongruent dolomite dissolution. Infiltration of Ca–SO₄–type ground water into the de-dolomitization zone facilitated calcite and brucite neo-formations at 13 > pH > 10.5 during advanced states of concrete deterioration and subsequently resulted in thaumasite precipitation at pH ~ 8.7. In this contribution, the reaction mechanisms and environmental controls of de-dolomitization are discussed in relation to the durability of concrete under sulfate attack.]]></description>
      <pubDate>Mon, 15 May 2017 15:16:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1464230</guid>
    </item>
    <item>
      <title>Effect of electrical field on TSA failure of cement-based materials</title>
      <link>https://trid.trb.org/View/1428148</link>
      <description><![CDATA[The impact of electrical field on the sulfate attack of cement-based materials at low temperatures was studied to rapidly detect Thaumasite Sulfate Attack (TSA) in the laboratory and in future engineering. Sulfate attack of cement paste with 30 wt% replacement of CaCO₃ powder soaked in Na₂SO₄ solution, MgSO₄ solution, or CaSO₄ solution was measured under the condition of 5 ± 2 °C when an electrical field was applied. Appearance changes and compressive strength of the samples were tested to evaluate the corrosion degree. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopic measurements were applied to study the microstructure of the corrosion product. The test results indicate that sample damage was obvious, compression strength declined rapidly, and ettringite and/or thaumasite were found in the corrosion product after applying the electrical field for 90 days. A muddy product with TSA characteristics was formed, and thaumasite composition was found in the corrosion product after applying the electrical field for 120 days when MgSO₄ solution was used as the corrosion medium. It is confirmed that an electrical field can accelerate TSA failure in cement-based materials.]]></description>
      <pubDate>Sat, 19 Nov 2016 17:45:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1428148</guid>
    </item>
    <item>
      <title>Investigation of concrete exposed to dual sulfate attack</title>
      <link>https://trid.trb.org/View/1373217</link>
      <description><![CDATA[Durability of concrete exposed to sulfates has primarily been studied on specimens fully-submerged in sulfate solutions. However, field experience shows that concrete exposed to sulfates can suffer from surface scaling above ground level due to physical attack. This damage has often been ignored and even confused with chemical sulfate attack. In this study, concrete partially-immersed in sulfate solutions and exposed to cyclic temperature and relative humidity was explored. Results show that concrete can experience dual sulfate attack. The lower immersed portion can suffer from chemical sulfate attack, while the upper portion can be vulnerable to physical attack. Lowering the water-to-binder ratio and moist-curing reduced surface scaling above the solution level, since the volume of pores was decreased. Although partial replacement of cement with pozzolans also decreased the pore volume, surface scaling increased due to increased proportion of small diameter pores and associated growth of capillary suction and surface area for evaporation.]]></description>
      <pubDate>Tue, 17 Nov 2015 08:24:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1373217</guid>
    </item>
    <item>
      <title>A modified ASTM C1012 procedure for qualifying blended cements containing limestone and SCMs for use in sulfate-rich environments</title>
      <link>https://trid.trb.org/View/1373230</link>
      <description><![CDATA[Blended Portland cements containing up to 15% limestone have recently been introduced into Canada and the USA. These cements were initially not allowed for use in sulfate environments but this restriction has been lifted in the Canadian cement specification, provided that the “limestone cement” includes sufficient supplementary cementitious material (SCM) and that it passes a modified version of the CSA A3004-C8 (equivalent to ASTM C1012) test procedure run at a low temperature (5 °C). This new procedure is proposed as a means of predicting the risk of the thaumasite form of sulfate attack in concretes containing limestone cements. The goal of the present study was to better understand how this approach works both in practice and in theory. Results from three different laboratories utilizing the CSA A3004-C8 test procedure are compared and analyzed, while also taking into account the results of thermodynamic modeling and of thaumasite formation experiments conducted in dilute suspensions.]]></description>
      <pubDate>Tue, 17 Nov 2015 08:24:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1373230</guid>
    </item>
    <item>
      <title>A new accelerated mortar bar test to assess the potential deleterious effect of sulfide-bearing aggregate in concrete</title>
      <link>https://trid.trb.org/View/1362050</link>
      <description><![CDATA[Deterioration of concrete structures incorporating sulfide bearing aggregates has been reported in Trois-Rivières area, Québec, Canada. In this case, iron sulfide oxidation and internal sulfate attack were observed.  The present study aims at developing a performance test that will reproduce, in the laboratory, the deterioration mechanisms observed on site. A two-phase accelerated mortar bar test was developed that consists 90 days of storage at 80 °C/80% RH, with two 3-h wetting cycles in a 6% bleach solution (Phase I) followed by up to 90 days of storage at 4 °C/100% RH (Phase II). Aggregates with oxidation potential presented an expansion over 0.15% during Phase I, while thaumasite formation potential is detected by rapid regain of expansion followed by destruction of the samples during Phase II. The control aggregates without sulfide mineral did not show any signs of deterioration in both phases of the testing program.]]></description>
      <pubDate>Tue, 25 Aug 2015 21:44:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1362050</guid>
    </item>
    <item>
      <title>Applying high resolution SyXRD analysis on sulfate attacked concrete field samples</title>
      <link>https://trid.trb.org/View/1365503</link>
      <description><![CDATA[High resolution synchrotron X-ray diffraction (SyXRD) was applied for a microstructural profile analysis of concrete deterioration after sulfate attack. The cement matrices consist of ordinary Portland cement and different amounts of supplementary cementitious materials, such as fly ash, natural pozzolana and granulated blast furnace slag. The changes of the phase composition were determined along the direction of sulfate ingress. This approach allows the identification of reaction fronts and zones of different phase compositions and conclusions about the mechanisms of sulfate attack. Two reaction fronts were localized in the initial 4 mm from the sample surface. The mechanism of deterioration caused by the exposition in the sulfate-bearing soil is discussed. SyXRD is shown to be a reliable method for investigation of cementitious materials with aggregates embedded in natural environments.]]></description>
      <pubDate>Tue, 25 Aug 2015 21:44:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1365503</guid>
    </item>
    <item>
      <title>The effect of temperature on the rate of sulfate attack of Portland cement blended mortars in Na₂SO₄ solution</title>
      <link>https://trid.trb.org/View/1362053</link>
      <description><![CDATA[Sulfate attack on Portland cement and Portland blended cement concretes is a well-researched field. However, the effect of varying temperature on the rate of sulfate attack requires further attention. This laboratory experiment studied temperatures of 23 °C, 10 °C, 5 °C, and 1 °C. Both Portland and Portland limestone cements were studied in combination with several supplementary cementing materials (SCMs). The mortar bars were submerged in 5% Na₂SO₄ (33,800 ppm SO₄²ˉ) solution for 15–30 months. At higher temperatures the SCMs, particularly the fly ashes, greatly improved the resistance to external sulfate attack. At lower temperatures the metakaolin improved the resistance to sulfate attack; the fly ashes had little to no effect on the low-temperature sulfate resistance. The alterations to sulfate resistance are attributed to: dilution of Portland cement in the presence of SCMs; additional nucleation sites provided by finely ground SCMs; and the pozzolanic and hydraulic reactions of the SCMs.]]></description>
      <pubDate>Tue, 25 Aug 2015 21:44:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1362053</guid>
    </item>
    <item>
      <title>NUMERICAL ANALYSIS FOR MORTAR DEGRADATED BY SULFATE ACID ATTACK CONSIDERING INFLUENCES OF ETTRINGITE AND GYPSUM</title>
      <link>https://trid.trb.org/View/1351588</link>
      <description><![CDATA[The purpose of this study is to develop the analytical method which can evaluate the change in physico-chemical property of mortar immersed in sulfuric acid solution. In this analytical approach, influences of sulfate acid attack were considered by diffusivity change of sulfate ions and physical change caused by chemical reaction of cement hydrate with sulfate ions. In the analysis, deposition condition of ettringite and gypsum was given by pH value and porosity which were calculated by the change in cement hydrate based on the experimental results. Finally, the validity of the analysis was discussed through parametric analyses in which the porosity value was varied.本研究は、硫酸溶液に浸漬したモルタルの物理化学的性質の経時変化を評価可能な解析手法を提案するものである。本解析手法では、硫酸による劣化を硫酸イオンの拡散および硫酸イオンと水和物との反応によってモデル化するとともに、pHを閾値としたエトリンガイトと二水セッコウの析出条件を導入した。また、実験値から回帰的にモルタル中の水和物量を求めることで、水和物量と析出物量に伴う固体体積の増減から空隙率を算出した。最終的に、空隙率の変化量を変数としたパラメトリック解析を行い、本解析手法の妥当性を検討した。]]></description>
      <pubDate>Mon, 27 Apr 2015 09:48:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1351588</guid>
    </item>
    <item>
      <title>A Required Condition of Thaumasite Formation in Marine Environments</title>
      <link>https://trid.trb.org/View/1141198</link>
      <description><![CDATA[In order to investigate the required conditions of thaumasite formation in marine environments, a series of experiments were carried out. The following factors were considered: cement and sand types, water/cement ratio (W/C), temperature, solution composition such as water, seawater, sulfate solution, and exchanging interval of solution. In the case of sulfate solution with a shorter exchange interval, typical external sulfate attack accompanying ettringite formation was observed at 5°C for higher W/C mortar. In the case of a longer exchange interval at 5°C, some differences were observed in the deteriorated texture depending on  sand types for higher W/C mortar. Surface texture was pealed out when rectangular mortar specimens made of limestone sand were immersed in seawater and sulfate solution. In the deteriorated part, thaumasite was identified. The increase in pH by prolonging an exchanging interval is estimated as a reason for thaumasite formation. In actual marine environments, seawater is continuously exchanged and this reduces the possibility of thaumasite formation even for concrete containing calcite. Stagnant condition is much more dangerous for thaumasite sulfate attack.]]></description>
      <pubDate>Mon, 25 Jun 2012 09:39:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1141198</guid>
    </item>
    <item>
      <title>Laboratory and Field Evaluations of External Sulfate Attack in Concrete</title>
      <link>https://trid.trb.org/View/1127033</link>
      <description><![CDATA[Sulfate attack is a complex form of deterioration that has damaged concrete structures throughout the world. Sulfate attack is particularly complex because the source of sulfates can be external or internal (delayed ettringite formation), and the distress can be chemical in nature, due to alteration of hydration of products, or physical in nature, due to phase changes in the penetrating sulfate solution. Although sulfate attack has been recognized as a cause of concrete distress for many years, it remains a controversial, confusing, and complex topic. There are many unresolved issues, far too many to be tackled in a single investigation. The research described in this report aims to address several of these lingering issues, especially those that are particularly relevant to the state of Texas.]]></description>
      <pubDate>Wed, 25 Jan 2012 14:21:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1127033</guid>
    </item>
    <item>
      <title>Sulfate Attack on Concrete: Effect of Partial Immersion</title>
      <link>https://trid.trb.org/View/1105270</link>
      <description><![CDATA[Traditionally, the extent of sulfate attack is qualified through visual rating or quantified by the percent expansion of slender bars completely submerged in sulfate solution. There are currently no standardized test methods that take into account the change in engineering properties because of deleterious mechanisms. Moreover, the exposure regime used to evaluate sulfate attack, complete immersion, is not typically representative of that encountered in the field. For these reasons, the objective of the research presented herein is to quantify the degree of sodium sulfate attack through the degradation of mechanical properties, specifically the compressive and splitting tensile load capacities of standard cylindrical specimens. A novel exposure regime is utilized wherein the specimens are only partially submerged in 5% sodium sulfate solution, creating an evaporation front similar to that of field exposure. It was found that the portion submerged in sulfate solution, although visually pristine, was the weaker portion of the cylinder for both mechanical tests, even though the other half showed extensive signs of surface disintegration caused by salt crystallization.]]></description>
      <pubDate>Fri, 29 Jul 2011 07:45:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1105270</guid>
    </item>
    <item>
      <title>Concrete Aggregate Durability Study</title>
      <link>https://trid.trb.org/View/981265</link>
      <description><![CDATA[There are many factors that affect the durability of Portland cement concrete (PCC), including the mix design and the materials used, the quality of construction, and the environment. Durability is not an intrinsic property of the concrete, but instead is related to how the material interacts with the environment. Durability-related deterioration is referred to as materials-related distress (MRD). Common MRDs include those caused by physical processes, such as freezing and thawing, or chemical processes, such as alkali-silica reactivity (ASR) and sulfate attack. This research project was undertaken to determine whether concrete used in the ADOT system is experiencing, or is potentially susceptible to, ASR or sulfate attack, and if so, to what degree. Based on this study, ADOT’s current practices are consistent with those of its neighboring states, but by no means are they the most rigorous, particularly related to controlling ASR. The following recommendations are made to improve ADOT’s approach to ASR and sulfate attack mitigation to ensure success in the future: (1) ADOT should review its supplementary cementitious material (SCM) specifications to ensure that those materials being used in its concrete have the desired effect of mitigating ASR and sulfate attack. (2) A number of neighboring states permit the use of ASTM C1157 performance-specified cements and ADOT should investigate allowing the use of these cements as well. (3) ADOT is following the current state-of-the-practice regarding aggregate screening for ASR susceptibility. New FHWA guidelines (Thomas et al. 2008A) recommend that long-term concrete prism testing be conducted in accordance with ASTM C1293, Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction, to establish an empirical relationship with the ASTM C1260 test results to ensure mitigation. This would require ADOT to embark on a long-term study to test their most common ASR-susceptible aggregates, but it is the only currently acceptable approach to developing confidence that the ASTM C1260/C1567 results accurately predict field performance.]]></description>
      <pubDate>Thu, 28 Oct 2010 14:25:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/981265</guid>
    </item>
    <item>
      <title>Durability of Concrete Containing Fine Pozzolan</title>
      <link>https://trid.trb.org/View/924892</link>
      <description><![CDATA[The incorporation of pozzolans such as fly ash enhances concrete durability by reducing permeability, increasing resistance to alkali silica reaction (ASR), sulfate attack, corrosion attack, etc.  It has long been recognized that the activity of fly ash is much improved by increasing its fineness.  Fine fly ash can be manufactured by grinding or by selective classification using air classifiers.  In the past both of these approaches have typically been cost prohibitive.  However, recently it has become possible to commercially manufacture an ultra fine fly ash (UFFA) with an average particle size of approximately 3 micrometer (90% passing 7 micrometer) in large quantities.  This paper discusses the fresh and hardened properties of concrete made with UFFA.  Certain durability testing for Rapid Chloride Penetration Resistance, chloride diffusivity, ASR, and sulfate attack were also conducted.  Similar early strengths and durability measures of silica fume concrete were observed, provided a slightly higher dosage of UFFA was used as well as 10%% less water amount.]]></description>
      <pubDate>Tue, 17 Aug 2010 10:44:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/924892</guid>
    </item>
    <item>
      <title>Durability of Self-consolidating Concrete to Sulfate Attack Under Combined Cyclic Environments and Flexural Loading</title>
      <link>https://trid.trb.org/View/887481</link>
      <description><![CDATA[Classical sulfate immersion tests for concrete have often given different behavior from that observed in real field exposure. Such tests do not consider other parameters existing in service that can affect the mechanisms and kinetics of sulfate attack. Conversely, the current shift towards performance-based standards and specifications for concrete requires the development of performance tests that better correlate to field conditions. Such holistic tests can effectively evaluate the service life of normal and emerging types of concrete. With the growing use of self-consolidating concrete (SCC) in various infrastructure applications, it has become necessary to establish reliable data on its durability. In this study, the durability of a wide range of SCC mixture designs to sulfate attack is assessed when other concomitant damage mechanisms (cyclic environmental conditions and flexural loading) are considered. Based on the tested mixture design variables (type of binders, air-entrainment, sand-to-total aggregates mass ratio, and hybrid fiber reinforcement), potential performance risks (in terms of physico-mechanical parameters) under such a combined exposure were identified. Those risks were not tangible under a full-immersion test method. Thermal, mineralogical, and microscopy analyses revealed the coexistence of complex deterioration processes in SCC under combined exposure, which is fundamentally different from the occurrence of a single damage mechanism (sulfate attack).]]></description>
      <pubDate>Mon, 20 Apr 2009 07:45:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/887481</guid>
    </item>
    <item>
      <title>Sulfate Attack on Cementitious Materials Containing Limestone Filler--A Review</title>
      <link>https://trid.trb.org/View/887484</link>
      <description><![CDATA[This review summarizes the results of sulfate performance in laboratory and field tests where limestone is used as a constituent of cement (PLC) or as a sand replacement where it is particularly beneficial to the properties of self compacting concretes (SCC). Laboratory studies on paste, mortar, or concrete specimens exposed to Na2SO4 and MgSO4 solutions in a wide range of concentrations at different temperatures as well as mixtures with different compositions, cement compositions, and limestone proportions are considered in a conceptual analysis as for the resistance to external sulfate attack and, especially, thaumasite sulfate attack. A detailed analysis of environmental aggressiveness (concentration, temperature, and pH), mixture composition, and cement composition used in each study are presented for PLC and SCC. Reported field studies are also shown, only a few cases have used limestone filler in their composition. A conceptual graphical analysis is then proposed to relate the degree of surface deterioration and mineralogical composition of attacked surface to the main variables of external sulfate attack: water/cementitious material ratio, limestone content, and C3A content of the cement. Observation of graphical analysis clearly shows that deterioration by ESA is mainly governed by effective w/c ratio and C3A content of the cement. Surface damage is controlled when low effective w/c ratio and low C3A are used. In MgSO4 solution, low temperatures increase the degree of deterioration. Thaumasite is the last attack stage in the different sulfate environments.]]></description>
      <pubDate>Mon, 20 Apr 2009 07:45:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/887484</guid>
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