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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>
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    <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>Long-Term Behavior of Ground Anchors and Tieback Walls</title>
      <link>https://trid.trb.org/View/2549172</link>
      <description><![CDATA[The purpose of this project is to advance the state of knowledge on the long-term behavior of ground anchors and make practical recommendations. Two important issues were addressed: long-term movements and corrosion. For the long-term movements, some of the main findings from the physical and numerical simulations are: 1. Given the same total anchor length, grouted anchors with a short tendon bond length have higher capacities and lower creep rates than grouted anchors with a long tendon bond length. 2. The capacity of grouted anchors in a stiff clay was found to increase over five years even when under load over the five years. 3. The power law model s₁/s₂=(t₁/t₂)n  where s₁ and s₂ are the anchor movements at time t₁ and t₂ fits the data well and may be used to predict long-term movements. 4. A delayed failure occurred in triaxial tests on a clay when the stress level was larger than the yield stress of the soil. 5. Long-term horizontal movements can develop in anchored walls if the vertical capacity of the soldier piles is not sufficient to resist the downdrag from the retained soil. 6. The power law model can also be used for the long-term movement of walls. 7. The bending moment profile over the long term tends to shift towards smaller moments at the anchor points. 8. The anchor loads seem to vary very little as a function of time (±10% after five years). 9. An earth pressure coefficient chart is given to design anchored walls for a targeted deflection. For the corrosion issues, some of the main findings from the laboratory tests and literature review are: 1. Anchor failures have been reported and attributed primarily to a lack of protection and bending stresses. 2. About half of the failures occurred at the anchor head, half within the unbonded length, and very few within the bonded length. 3. The time to failure varied from a few weeks to 31 years. 4. The usual indicators of corrosion were confirmed by laboratory tests: soil resistivity, soil pH. 5. The Electrochemical Impedance Spectroscopy test (EIS) is proposed for measuring the corrosion rate for a given soil. 6. The EIS tests performed in the laboratory showed that the corrosion rate of the steel varies drastically for various protection coatings from 0.34 mm/yr for no protection to 10 to the -8 power mm/yr for fusion bonded epoxy with 3 x 10 to the -3 power mm/yr for grout cover. 7. The time to failure of an anchor can be estimated once the corrosion rate is known.]]></description>
      <pubDate>Tue, 24 Jun 2025 17:43:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2549172</guid>
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      <title>Free Acid in Soil Materials Exposed by Excavation for Highways in East Texas</title>
      <link>https://trid.trb.org/View/2549147</link>
      <description><![CDATA[Recurring failure of three applications of mulch sod on roadsides of Interstate 20 near Tyler, Texas led to a closer examination of soil material on the face of the cut slopes. The exposed materials on the slopes had pH values ranging from 2.5 to 4.0. Material from the surface of the cut slope was more acid than underlying materials. A general positive relationship was found between sulfate content and degree of soil acidity. The acid condition is postulated to arise from the oxidation and hydrolysis of the iron sulfide compounds from in the original sediments. However, the detrimental effect on plants apparently is a result of the low pH which solubilizes iron and aluminum to toxic levels. Studies are underway to overcome this undesirable soil condition and permit establishment and growth of plants for erosion control on roadsides where these materials occur.]]></description>
      <pubDate>Mon, 16 Jun 2025 11:26:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2549147</guid>
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    <item>
      <title>Study on the effect of acid rain erosion on the adhesion properties of asphalt-aggregate interface</title>
      <link>https://trid.trb.org/View/2487689</link>
      <description><![CDATA[This study investigates the impact of acid rain on the adhesion properties of the asphalt-aggregate interface in asphalt mixtures. By employing surface-free energy theory and the sessile drop method to analyse wetting behaviour, the adhesion work and energy indicator ER were calculated. The interface adhesion characteristics were evaluated using the water boiling method and pull-off tests. It was found that acid rain significantly reduces the interface adhesion work, which worsens with increasing erosion cycles and concentrations. The ER value decreases, adhesion becomes poorer and the lower the pH value, the more severe the damage. The acidic environment accelerates the stripping of the asphalt film and weakens the interactive forces. Acid rain increases the polarity between asphalt and aggregates, reducing the adhesion energy and leading to failure. SBS-modified asphalt exhibits better adhesion performance than 70# petroleum asphalt.]]></description>
      <pubDate>Mon, 17 Feb 2025 17:09:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2487689</guid>
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    <item>
      <title>Chemical Resistance of Synthetic Fiber-Reinforced Concrete Pipes in Highly Corrosive Environments</title>
      <link>https://trid.trb.org/View/2423195</link>
      <description><![CDATA[Among different components of the US highways and roads, concrete pipes are one of the most important parts of these infrastructure. Currently, most of the concrete pipes that are produced in the US are made from steel-reinforced concrete composite, and this system is prone to deterioration and steel corrosion during the service life of these pipelines. In this study, a newly developed synthetic fiber-reinforced concrete composite was studied to determine its chemical resistance in highly acidic environments with accelerated aging methods. Actual reinforced concrete pipes with 0.54% fiber volume fractions were immersed in low pH solutions and elevated temperatures. The D-load test results showed that specimens that were immersed in pH2 solutions lost their ultimate D-load capacity by 20% after 1 year, and pH4 specimens showed an 18% load decrease at the same time. Furthermore, by using SEM and EDX analysis, the chemical composition of specimens that were extracted from these pipes was analyzed. The results showed that at the early stages of the immersion tests, the surface of the pipes in pH4 solution did not absorb a significant amount of sulfur, and it shows that these specimens have not deteriorated significantly. With longer immersion duration, the amount of sulfur element on the surface of the specimens increased gradually, and for pH2, the surface was mostly saturated after 5 months of immersion. For pH4, this value was constantly increasing, and similar to the mechanical tests, pH4 results were converging to the same value of pH2 results. The findings of this research would pave the road to determine the service life of this composite in highly corrosive acidic environments.]]></description>
      <pubDate>Sat, 26 Oct 2024 16:09:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2423195</guid>
    </item>
    <item>
      <title>Effect by Different Factors on Ductility of Evaporated Residue of Modified Emulsion Asphalt</title>
      <link>https://trid.trb.org/View/2203649</link>
      <description><![CDATA[The ductility is an important property of evaporated residue of modified emulsion asphalt, and in which the modified asphalt is the main component. But the ductility of the modified asphalt will change after treated by emulsification. In order to analyze the influence of different factors on the ductility of the evaporated residue of modified emulsion asphalt, the ductility values of the residue were measured with different emulsifiers, solution PH values and stabilizers, and the change laws and effect mechanism of the ductility were analyzed. The test results show that the ductility of the evaporated residue of modified emulsion asphalt is sensitive to different emulsifiers, solution PH values and stabilizers. The ductility of the modified asphalt will have great loss after treated by emulsification. The ductility of the evaporated residue will present different change laws with different emulsifiers and modified asphalt; the ductility will increase as the solution PH value increased; the ductility loss of the residue caused by the organic stabilizer is larger than the inorganic salt stabilizer; and the change laws of the ductility loss are different caused by the content change of the two kind of stabilizers.]]></description>
      <pubDate>Sat, 03 Aug 2024 16:26:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2203649</guid>
    </item>
    <item>
      <title>Influence of Asphalt Emulsion Formulation Parameters on the Fluidity of Cement Asphalt Mortar for High-Speed Rail Tracks</title>
      <link>https://trid.trb.org/View/2409570</link>
      <description><![CDATA[The objective of the present study is twofold: firstly, to evaluate the influence of asphalt emulsion properties on the fluidity characteristics of cement asphalt mortar (CAM) for high-speed railway (HSR) track systems; and secondly, to propose a testing protocol that effectively differentiates the asphalt emulsions suitable for CAM with respect to fluidity requirement, considering specific requirements for the application. The study involved assessing CAM fluidity under various emulsion formulation variables, including the pH, residual asphalt content, and emulsifier dosage. In addition, three different test methods were evaluated for their suitability as the protocol for asphalt emulsions evaluation for CAM production in HSR applications. The results showed that the pH of the asphalt emulsion significantly affects the fluidity of the CAM, with cationic emulsions demonstrating less stability because of high alkaline conditions of CAM, while anionic/non-ionic emulsions exhibited stable fluidity. Fluidity in CAM is observed when an asphalt emulsion possesses an optimal micelle concentration, which effectively resists coagulation. The findings emphasize the importance of considering both upper and lower limits for residual asphalt content in emulsion specifications for CAM production. Emulsifier dosage also played a role, with high emulsifier dosages leading to high fluidity in CAM. The study introduced a fluidity ratio test as a suitable method for selecting asphalt emulsions for CAM production for HSR track systems.]]></description>
      <pubDate>Sat, 03 Aug 2024 16:24:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2409570</guid>
    </item>
    <item>
      <title>Instrument for Field Monitoring of Carboxylate Coolants and Heat-Exchange Fluids</title>
      <link>https://trid.trb.org/View/1787968</link>
      <description><![CDATA[For several years now, organic acid based coolants and heat exchange fluids have been introduced on the automotive and industrial market place. The organic acid based coolants provide improved high temperature aluminum corrosion protection and longer drain intervals when compared to traditional coolants. In order to evaluate the organic acid based coolant quality in the field; the end user needs to be able to check several physico-chemical parameters of the coolant. First of all the amount of carboxylate based inhibitors should be determined because the customers can top the system with water. As a result the carboxylates can drop under the minimum required inhibitor level. Secondly, contamination levels from traditional phosphate or borate containing coolants or from the frequently used hybrid coolants-which contain both carboxylates and traditional inhibitors- need to be determined, to give the user an indication about the possible interference of corrosion inhibition technologies used in the examined coolant. Thirdly, the pH of the used coolant provides information on further suitability for use. pH values that are too high or too low may be detrimental to some engine- or heat-exchange system materials. Finally a check on the freezing point of the coolant will provide information on frost protection.         In this paper the authors show the possibilities of an acid-base titration to determine the total carboxylic acid inhibitor content and the presence of contamination in coolants. A refractive index probe is used to measure the glycol content of aqueous coolant mixtures. Further, based on the two above described techniques a user-friendly quality-checking coolant instrument is described which allows measurements of the pH; the contamination level and the total carboxylate based inhibitor content of the test solution. An integrated refractometric determination of the freezing point can also be performed on the same coolant sample. The instrument will allow the user to determine within minutes the essential parameters of an organic acid based coolant on which the user can make well founded decisions on the quality of the coolant at hand.]]></description>
      <pubDate>Mon, 24 Jun 2024 15:47:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787968</guid>
    </item>
    <item>
      <title>Comprehensive properties assessment of asphalt binder under aqueous solutions with different pH values and its gradient damage behaviors</title>
      <link>https://trid.trb.org/View/2326931</link>
      <description><![CDATA[This study characterized the morphology, high-temperature property, rheological property, adhesion, cohesion, and chemical component of asphalt binder under aqueous solutions of different pH values. Then the physicochemical properties of asphalt binder were comprehensively evaluated by the improved radar chart. The properties of asphalt binder stripped layer-by-layer were explored to elucidate its gradient damage behaviors. The results indicate that the pH 3 solution reveals the greatest impact on the morphology of 90 asphalt (90 A) and styrene-butadiene-styrene modified asphalt (SBS MA), leading to the wide cracks on 90 A and the network cracks on SBS MA. The comprehensive assessment index of 90 A exposed to pH 3, pH 5, pH 7, pH 9, and pH 11 solutions can be reduced by 20.8%, 20.2%, 1.5%, 14.0%, and 25.5%, respectively. While for SBS MA, its corresponding values variation are 23.2%, 17.7%, 4.6%, 8.7%, and 13.0%, respectively. The acid solutions significantly affect the comprehensive properties of 90 A, but their pH value has little effect. 90 A exposure to the higher pH value of alkali solution reveals the worse comprehensive properties. Acid solute and alkali solute can aggravate the effect of aqueous solution on the comprehensive properties of SBS MA, and the degree of aggravation increases with the increase of solute concentration. The properties of asphalt binders exhibit varied gradient damage behaviors under different solute environments. The most serious damage occurs at 25–50 µm of 90 A and 0–50 µm of SBS MA. This study facilitates an accurate understanding of the mechanism of pavement distresses and composition design and construction utilization of asphalt binders.]]></description>
      <pubDate>Wed, 28 Feb 2024 13:58:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2326931</guid>
    </item>
    <item>
      <title>Effects of Carbon Sequestration on Corrosion of Reinforced Concrete in Kansas</title>
      <link>https://trid.trb.org/View/2255792</link>
      <description><![CDATA[Cement production is the third largest producer of carbon dioxide worldwide, with each cubic yard of concrete responsible for an estimated 400 lb of CO2. The industry has taken many steps to mitigate this impact, ranging from the increasing use of SCMs to a shift to Type IL portland cement. While these approaches focus on reducing the demand for portland cement, one more recent development involves collecting carbon dioxide from industrial application and sequestering it in concrete. CarbonCure has developed a technology that injects carbon dioxide into concrete during the mixing process, claiming that up to 25 lb/yd3 of CO2 can be permanently mineralized in the concrete. CarbonCure also claims this process increases the compressive strength of concrete; however, the effect of this sequestration on the long-term durability of concrete has not been established.
Concrete will slowly absorb CO2 from the atmosphere over time in a process known as carbonation. In the process of carbonation, CO2 reacts with calcium hydroxide (Ca(OH)2), a component of hydrated portland cement, to produce calcium carbonate and water: CO2 + Ca(OH)2 → CaCO3 + H2O.
While the process of carbonation does not significantly impact the strength of concrete, it does lower the pH. Newly cast concrete typically has a pH of around 13.5. Steel reinforcement will corrode in concrete if the pH drops below 11.5, even in the absence of chlorides. Furthermore, the resistance of reinforcement to chloride-induced corrosion decreases as the pH decreases. As a result, carbonation can reduce durability of reinforced concrete even at moderate reductions in pH.
Given the impact that atmospheric carbonation can have on the durability of reinforced concrete, it is critical to establish what impact, if any, the addition of CO2 to plastic concrete has on the corrosion resistance of reinforced concrete structures. This research proposal aims to: (1) establish the effect of CarbonCure technology on early and long-term pH of concrete; and (2) determine the corrosion resistance of reinforced concrete with CarbonCure relative to conventional reinforced concrete.
]]></description>
      <pubDate>Wed, 27 Sep 2023 11:45:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2255792</guid>
    </item>
    <item>
      <title>pH Profiles around Pervious Concrete in Fresh Water</title>
      <link>https://trid.trb.org/View/1989545</link>
      <description><![CDATA[Pervious concrete stormwater management systems are being adopted in many areas of the country. Additional applications might include erosion control by streams and other waterways, or as pavements in areas prone to flooding. Concrete in contact with waters typically increases the pH, especially in the first year of use prior to significant carbonation. Open system batch tank testing was performed on pervious concrete specimens of varying young ages to analyze the pH profiles that might develop over time. The results indicate that the higher pH values remain close to the specimens. These results imply that the use of pervious concrete near waterways will not have a large spatial impact on pH, especially under dynamic conditions.]]></description>
      <pubDate>Mon, 28 Nov 2022 09:17:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1989545</guid>
    </item>
    <item>
      <title>Durability of Metal Pipe Culverts</title>
      <link>https://trid.trb.org/View/2012629</link>
      <description><![CDATA[A field and laboratory investigation by the Idaho Department of Highways of the performance of galvanized metal pipe with particular emphasis on service life, indicates a life expectancy in excess of 40 years except in a few areas. Soil in timbered areas and in pasture lands with excess soil moisture reduced the life expectancy to less than 30 years, and in a few installations to 20 years. The test devised by the California Highway Department using soil pH and electrical resistivity appears to give a satisfactory estimate of service life, although few installations are of an age to verify the predicted life. It is recommended that this test be used for predicting service life, and that when the life predicted is less than 40 years, the pipe be bituminous coated. Installations of aluminum pipe and fiber glass coated concrete box culverts were reported, but no conclusions can be drawn as their service life is insufficient to warrant any such attempt.]]></description>
      <pubDate>Sun, 11 Sep 2022 18:58:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2012629</guid>
    </item>
    <item>
      <title>Properties of Concrete Produced with Admixtures Intended to Inhibit Corrosion</title>
      <link>https://trid.trb.org/View/1920206</link>
      <description><![CDATA[A study was conducted to evaluate properties of fresh and hardened concrete produced with Hawaiian aggregates and admixtures that are added to concrete to protect reinforcing steel from corrosion. DCI, Rheocrete CNI, Rheocrete 222+, FerroGard 901, Xypex Admix C-2000, a latex-modifier, silica fume, and fly ash were the admixtures intended to slow the corrosion process. These admixtures were used in mixtures designed by varying the proportions of mixtures that were already considered to be corrosion resistant. Compressive strength, elastic modulus, and Poisson’s ratio were determined for all mixtures. DCI, Rheocrete CNI, and silica fume significantly increased compressive strength, while Xypex Admix C-2000 and the latex-modifier reduced compressive strength. Concrete permeability, the ability to reduce chloride penetration, and pH were evaluated for selected mixtures. Silica fume and the latex-modifier produced substantial reductions in permeability. ACI equations for elastic modulus overestimated the elastic modulus values for almost all of the mixtures. The average overestimation was 14% for two equations provided by ACI 318, and 8% for the equation recommended by ACI 363 for high strength concrete.]]></description>
      <pubDate>Tue, 19 Apr 2022 13:06:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1920206</guid>
    </item>
    <item>
      <title>Corrosivity of Water-Soluble Sulfate Ions in Simulated Pore Water Solutions and Different Types of Grout Samples</title>
      <link>https://trid.trb.org/View/1862525</link>
      <description><![CDATA[While sulfate-induced corrosion problems have been observed in segregated grout, the existing literature lacks useful information about the role of sulfate ions in the corrosion process. To produce empirical data on the corrosivity and concentration of water-soluble sulfate ions under different grout conditions, researchers performed a laboratory study. In low-pH aqueous solutions, simulating carbonated bleed water and grout pore water, water-soluble sulfate ions were as detrimental as chloride to post-tensioned (PT) strands if the strands were not protected by high-pH grout. In high-pH aqueous solutions, sulfate was less corrosive than chloride. When chloride and sulfate of equal concentrations coexisted in different pH aqueous solutions, chloride was the dominant species in determining corrosivity of the solutions. Like chloride ions, water-soluble sulfate ions showed temperature-dependent corrosivity in that corrosion was more severe at the elevated than ambient temperature. Mean corrosion rates at the near-freezing temperature were less than 10 percent of those measured at the ambient temperature, regardless of sulfate concentration. The content of water-soluble sulfate in raw grout powders ranged from 0.35 to 1.0 percent by weight of sample, but most of the sulfate became bound to the hardened grout and the water-soluble sulfate reduced to 0.1 percent. Aged/expired raw grout was more prone to segregation and readily released water-soluble sulfate ions into the segregated grout. Petrographic examination and chemical analyses revealed that pore water and soft/wet segregated grout retained 100 times the water-soluble sulfate and more than five times the total sulfur content than dried and hardened grout did. This is because water-soluble sulfate ions can migrate via water movement toward areas with more moisture. If the segregated grout maintains a low-pH environment by carbonation, corrosion can be initiated on a strand in direct contact with a carbonated layer of segregated grout with a concentration of water-soluble sulfate ions as low as 0.05 percent by weight of sample. Just a thin film of carbonation, in intimate contact with the steel, is sufficient to induce the intensive corrosion.]]></description>
      <pubDate>Fri, 23 Jul 2021 15:21:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1862525</guid>
    </item>
    <item>
      <title>Investigation of Moisture Damage in Open Graded Asphalt Friction Course Mixtures with Basic Oxygen Furnace Steel Slag as Coarse Aggregate under Acidic and Neutral pH Environments</title>
      <link>https://trid.trb.org/View/1716589</link>
      <description><![CDATA[Open graded asphalt friction courses (OGAFCs) are specialty asphalt mixtures used to improve skid resistance and surface drainage. OGAFCs have additional benefits of reduced splash and spray, and lower tire–pavement interaction noise. Prolonged exposure to rainwater and load transfer through stone-on-stone contact in OGAFCs demands aggregates that are strong and hydrophobic. Rainwater acidity is expected to affect the aggregate–asphalt bond and thus moisture damage performance of OGAFC. This paper investigates the effect of rainwater acidity on moisture sensitivity of OGAFC mixtures with different aggregate types (natural aggregate, basic oxygen furnace (BOF) steel slag, and combinations of both) and modified binder types. For the first time, the present research reports the moisture damage potential of BOF OGAFC mixtures under different moisture conditioning environments created by varying the pH of contact water. With different combinations of BOF slag and natural aggregates (100:0, 25:75, 50:50, 75:25, and 0:100), and binders (polymer and crumb rubber modified), OGAFC mixtures were characterized for moisture damage through tensile strength ratio, wet Cantabro abrasion loss, and modified boiling water tests. Functional aspects of OGAFC mixtures subjected to moisture conditioning under different pH environments were also evaluated through permeability testing. Results showed that an acidic environment exacerbated the moisture damage, however, OGAFC mixtures containing BOF slag showed better performance than the control mixture (with natural aggregates only). Inclusion of BOF slag in OGAFC mixtures enhanced resistance to moisture damage under both pH environments. OGAFC mixes with 100% BOF slag content performed the best considering all moisture damage tests under both conditioning environments.]]></description>
      <pubDate>Fri, 26 Jun 2020 17:18:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1716589</guid>
    </item>
    <item>
      <title>Laboratory Investigation of Underwater Concreting</title>
      <link>https://trid.trb.org/View/1713390</link>
      <description><![CDATA[Concrete and grout with minimal washout are required for underwater placements from both a structural and environmental perspective. Resistance to washout and consolidation are factors difficult to achieve underwater using conventional concretes or grouts. Cohesive and self-consolidating concrete and grouts could provide the needed washout resistance and omission of consolidation efforts with mechanical vibration.  Cohesive concrete and grout mixtures with high flowability that have satisfactory strength and durability would satisfy both the structural and environmental needs of underwater placement. This study investigated the performance of both concrete and grout mixtures with and without self-consolidation in addition to various types of viscosity modifying admixtures for cohesiveness in an underwater environment. The laboratory study investigated concrete and grout mixtures resistant to washout and segregation underwater.  The study found that mass loss can be reduced through the choice of mixture ingredients, especially viscosity modifying admixtures; proper mixture proportions; use of grout bags; and the lowering of the slump or slump flow of the mixture. However, reduction of mass loss was not directly related to reduction of pH. To reduce the pH that is harmful to aquatic life, alternative cementitious materials—such as rapid set cements or magnesium phosphate binders—can be used. In addition, the increase of pH underwater mainly occurs while concrete is still plastic; thus, reducing the setting time would limit the pH exposure. The study recommends that the Virginia Department of Transportation update existing special provisions on underwater concreting to include the findings of this study.]]></description>
      <pubDate>Tue, 16 Jun 2020 16:24:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1713390</guid>
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