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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>
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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>Mechanisms of k-struvite formation in magnesium phosphate cements</title>
      <link>https://trid.trb.org/View/1436706</link>
      <description><![CDATA[The formation of magnesium phosphate cements is based on an acid-base reaction between potassium dihydrogen phosphate and magnesium oxide. The reaction leads to the formation of k-struvite as main product. These cements, due to their specific properties, represent an interesting alternative solution for niche applications, such as cold weather repair materials or waste treatment materials. However, scarce information is found in the literature when it comes to certain aspects linked to the consolidation of the material. The main purpose of this study is thus to better understand the influence of both the pH and the species that are present in solution on the precipitation of the k-struvite. The present study highlights the fact that the consolidation of the material involves the formation of an initial transition phase. Indeed throughout the reaction, newberyite is first formed. With the pH increase, newberyite is dissolved, and these conditions enhance the crystallization of k-struvite.]]></description>
      <pubDate>Mon, 19 Dec 2016 18:18:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1436706</guid>
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    <item>
      <title>Investigation of magnesium phosphate cement hydration in diluted suspension and its retardation by boric acid</title>
      <link>https://trid.trb.org/View/1418943</link>
      <description><![CDATA[Magnesium phosphate cements (MPCs) are used for rapid repair works, but they may also offer prospects for the stabilization/solidification of deleterious waste. MPCs contain calcined magnesium oxide and a water-soluble acid phosphate, such as potassium dihydrogen phosphate (KH₂PO₄). The main precipitated hydrate is then K-struvite (MgKPO₄·6H₂O). This work aims at giving new insight into the processes involved in its formation. Since cement hydration is very rapid, the second objective is to understand how boric acid, a common admixture for field application, retards cement hydration. A multi-stage process is evidenced in diluted suspension: MgHPO₄·7H₂O likely precipitates first. This phase is then destabilized to form Mg₂KH(PO₄)₂·15H₂O which is finally converted into K-struvite and cattiite (Mg₃(PO₄)₂·22H₂O). Boric acid doesn't slow down the initial dissolution of the reactants, but rather retards the precipitation of the products. Besides, it tends to favor the formation of cattiite against that of K-struvite.]]></description>
      <pubDate>Sat, 03 Sep 2016 12:24:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1418943</guid>
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    <item>
      <title>Preparation of magnesium phosphate cement by recycling the product of thermal transformation of asbestos containing wastes</title>
      <link>https://trid.trb.org/View/1395949</link>
      <description><![CDATA[Asbestos containing wastes have been employed for the first time in the formulation of magnesium phosphate cements. Two samples were mixed with magnesium carbonate and calcined at 1100 and 1300 °C. Under these conditions, complete destruction of asbestos minerals is known to occur. The product, containing MgO, after reaction with water-soluble potassium di-hydrogen phosphate, led to the formation of hydrated phases at room temperature. Crystalline and amorphous reaction products were detected, with the latter being likely the metastable precursor of the former. Measured strengths were found to be in line with data from the literature, suggesting that this material may be used as cement. The process here described represents a viable recycling opportunity for this class of hazardous wastes. Simultaneous destruction of asbestos minerals and formation of reactive MgO during thermal treatment, bring benefits in terms of energy requirements and preservation of natural resources in cement manufacturing.]]></description>
      <pubDate>Mon, 08 Feb 2016 16:32:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1395949</guid>
    </item>
    <item>
      <title>Effect of early hydration temperature on hydration product and strength development of magnesium phosphate cement (MPC)</title>
      <link>https://trid.trb.org/View/1371063</link>
      <description><![CDATA[This paper investigates the effect of early hydration temperatures on hydration products and strength development of magnesium phosphate cement (MPC). MPC paste specimens with borate contents of 3%, 6%, 9% and 12% are prepared and cured in different air temperatures and in the adiabatic condition. The internal hydration temperatures are measured by pre-embedded temperature probes. MPC samples with different hydration temperatures are also obtained by using thin slice samples. The hydration products in MPC samples with different hydration temperatures are analyzed by X-ray diffractometer (XRD) and scanning electron microscope (SEM) and the strength development is also measured. The results show that NH₄MgPO₄·6H₂O is the major hydration product and beneficial to strength development of MPC at hydration temperature below 70 °C. NH₄MgPO₄·H₂O is another major product, which significantly decreases the strength, when the temperature is higher than a critical temperature between 70 °C and 75 °C. NH₄MgPO₄·H₂O can directly form in the MPC paste, and comes from the decomposition of NH₄MgPO₄·6H₂O when the temperature is above 75 °C. With temperature elevation and duration extension, NH₄MgPO₄·6H₂O decomposes rapidly, and even entirely when the temperature is above 100 °C. The borate content has no effect on the types of major hydration products and the critical temperature.]]></description>
      <pubDate>Wed, 14 Oct 2015 08:52:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1371063</guid>
    </item>
    <item>
      <title>Sustainable Binder for Severe Environment: Magnesium-Based Cementitious Material</title>
      <link>https://trid.trb.org/View/1212182</link>
      <description><![CDATA[In this paper, a severe environmental sustainable binder, Magnesium- Phosphate Cement (MPC), is introduced. The magnesium cement can be obtained by properly mixing magnesia particles, fly ash, phosphate and other additives. In the paper, the recent developments of the material at the Hong Kong University of Science and Technology are presented. The investigation shows that the material has superior properties to the Portland cement such as high early strength, excellent volume stability, better acid resistance, good fire resistance, ability of setting and hardening under freezing conditions, and excellent resistance to deicer scaling freezing and thawing cycling. Compared to Portland cement, magnesium phosphate cement is more suitable for applications in severe environmental conditions.]]></description>
      <pubDate>Wed, 29 Aug 2012 14:36:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1212182</guid>
    </item>
    <item>
      <title>Full-Scale Field Testing of Rapid-Setting Materials for Slab Replacement</title>
      <link>https://trid.trb.org/View/890285</link>
      <description><![CDATA[Improvements in rapid-setting cementitious materials have increased their usage in the rapid repair of rigid pavements. As applied to airfields, high-performance concrete materials with early strength gain characteristics have helped to minimize maintenance time to return the area back into service. Numerous products are available. Currently, the commercial market teems with available products, and it continues to grow, with both new products entering the market and new formulations of existing products. A test program assessed the suitability of using rapid-setting materials for rapid slab replacement on an airfield. Among the materials tested in this study were a new hydraulic cement and a magnesium-phosphate-based (MPB) cement. Laboratory testing, based on an existing test protocol, was conducted to characterize the candidate materials prior to use in the full-scale field application. During a full-scale trial, the materials were used for rapid slab replacement and then trafficked with a load cart for a maximum service life of 5,000 passes. Results from the laboratory testing suggested that the MPB cement may not be suitable for the field trial. Yet, this material was one of the top performing materials in the field trial. Refinement of the test protocol is recommended to include testing at temperatures similar to those expected where the material will be used. In addition, other test procedures need to be identified and tested to address the issue of potential materials that may yield good field performance but are excluded from field use under the current protocol recommendations.]]></description>
      <pubDate>Wed, 17 Jun 2009 12:07:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/890285</guid>
    </item>
    <item>
      <title>Effect of Early-Age Temperature Rise on the Stability of Rapid-Hardening Cement Fiber Composites</title>
      <link>https://trid.trb.org/View/787598</link>
      <description><![CDATA[The fiber composites reported herein comprise a particular class of multiphase materials in which the major volumetric phase, the binder, is a rapid-hardening cement-based material and the minor volumetric phase, the reinforcement, is a fibrous steel material. A further feature of these composites was that the proportion of fiber to binder was significantly high, up to 20% by volume. The work was limited to commercially available steel fibers and cements; the latter were a magnesium phosphate and an accelerated calcium aluminate. The objectives of this work were (1) to carry out a brief review on rapid-hardening cements; (2) to identify the influence of early-age temperature rise on the stability of cement grouts; and (3) to investigate their early-age strength development. The work established that both cements could be used as binders in fiber composites.]]></description>
      <pubDate>Wed, 23 Aug 2006 07:58:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/787598</guid>
    </item>
    <item>
      <title>High-Early-Strength Magnesium Phosphate Cement with Fly Ash</title>
      <link>https://trid.trb.org/View/771485</link>
      <description><![CDATA[To understand the mechanism of fly ash in a novel magnesia phosphate cement (MPC), the microstructure and properties were investigated in the present study.  Reference specimens without the incorporation of fly ash were also investigated for comparison purposes. The effect of fly ash content on the properties of MPC was studied with two dead burnt magnesia materials with different MgO contents and fineness. The results demonstrated that fly ash does improve the bonding and compressive strength of MPC, even at very early ages. Fly ash content of 30 to 50% has the best improving effect on MPC, despite the two types of magnesia. Due to the difference of MgO content and particle fineness of two dead burnt magnesia materials, MPC mortars with finer magnesia revealed higher compressive strength. The incorporation of fly ash does not retard the setting reaction of MPC, but it does reduce its total heat evolution. The hydrates and microstructure of MPC paste were examined by an x-ray diffractometer, scanning electron microscopy-energy dispersive x-ray analysis (SEM-EDX), and Fourier transform infrared (FTIR) spectroscopy. These techniques revealed that the products formed in MPC paste were crystal magnesium potassium phosphate hexahydrate and amorphous species. The particles of fly ash fill the voids of MPC paste and strongly bond together with hydrates of MPC. The microanalysis showed that the strengthening of fly ash to the cement might come from physical and chemical effects.]]></description>
      <pubDate>Thu, 29 Dec 2005 15:06:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/771485</guid>
    </item>
    <item>
      <title>Dolomite Used as Raw Material to Produce MgO-based Expansive Agent</title>
      <link>https://trid.trb.org/View/760545</link>
      <description><![CDATA[Shrinkage cracking occurs in construction frequently.  Several measures have been developed to eliminate the shrinkage cracking, and this paper examines the use of MgO-based expansive agent using dolomite as raw material .  The study tested the expansion of MgO-based expansive agents using two methods: by autoclaving test and by testing the expansion of the cement paste under curing conditions at 80 deg C.  Based on the two tests, the results demonstrate that mineral dolomite can be used as raw material to produce MgO-based expansive agents to compensate the shrinkage cracking of cement and concrete.]]></description>
      <pubDate>Mon, 03 Oct 2005 08:31:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/760545</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF SUSTAINABLE CEMENTITIOUS MATERIALS</title>
      <link>https://trid.trb.org/View/741558</link>
      <description><![CDATA[Portland cement (PC) concrete is the most popular and widely used building material because its raw materials are available over the world.  This paper introduces two types of sustainable cementitious composites, geopolymer and magnesium phosphate cement.  Compared with PC, these two cements possess some common and individual characteristics.  The paper presents recent developments of these two materials.  Investigation has shown that they have superior properties compared to PC such as high early strength, excellent volume stability, better durability, good fire resistance, and easy manufacture process.]]></description>
      <pubDate>Mon, 20 Sep 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/741558</guid>
    </item>
    <item>
      <title>DURABILITY OF MAGNESIA-PHOSPHATE GROUTS IN SULFATE SOLUTIONS</title>
      <link>https://trid.trb.org/View/665282</link>
      <description><![CDATA[In this work, 2 different magnesia powders were used to prepare magnesia-phosphate cements in combination with equal quantities of mono-ammonium phosphate. Two grouts containing 50% of each magnesia-phosphate cement and 50% Class F fly ash were prepared at a water-to-solids ratio of 0.25 and submitted in 3 wetting and drying cycles in deionized water, 20% ammonium sulfate solution, and 20% magnesium sulfate solution. Each cycle was composed of 4 weeks of immersion and 1 week of drying at 20 deg C. The samples were subjected to mass loss, compressive strength, and microstructure. Obtained results show a very good behavior of these grouts in magnesium sulfate solution. Their behavior in ammonium sulfate solution depends on initial porosity of the grout: expansive schertelite appears and develops without disorder when the grout is very porous. When porosity is limited, the grout disintegrates after 3 cycles in an aggressive solution.]]></description>
      <pubDate>Sun, 12 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/665282</guid>
    </item>
    <item>
      <title>A LABORATORY AND FIELD EVALUATION OF REQUIRED MATERIAL PROPERTIES FOR CONCRETE REPAIRS</title>
      <link>https://trid.trb.org/View/478627</link>
      <description><![CDATA[This study investigated the material properties necessary to ensure a successful concrete repair.  The information and data contained in this report will assist in the preparation of a repair material selection guideline, one that could aid engineers in the selection of the most appropriate repair material based upon the environmental conditions.  The study consisted of both a laboratory evaluation program and a field evaluation program.  The laboratory evaluation program identified and tested the most important repair material properties.  The field evaluation program consisted of both a qualitative and quantitative evaluation of existing repairs throughout Texas.  One of the primary objectives of the field visits was to investigate a wide range of typical repairs that can be expected in Texas.  The two evaluation programs can be synthesized into a single set of material selection guidelines.]]></description>
      <pubDate>Thu, 24 Apr 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/478627</guid>
    </item>
    <item>
      <title>EVALUATION OF NEW BONDING MATERIALS FOR ANCHORING DOWELS IN EXISTING CONCRETE. FINAL REPORT</title>
      <link>https://trid.trb.org/View/382029</link>
      <description><![CDATA[Test results of threaded rod and reinforcing bars bonded with either polyester resin capsules, vinylester resin capsules, portland cement grout or magnesium phosphate concrete are presented.  Tests included tension tests, shear tests, combined tension-shear tests, and creep tests at elevated temperatures. The parameters evaluated were edge distance, embedment depth, effect of elevated temperature on tension load, and the interaction of tension and shear.  Tables listing allowable shear and tension loads have been prepared for each bonding material.  An interaction equation for anchors loaded in both tension and shear is also given.]]></description>
      <pubDate>Wed, 01 Dec 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/382029</guid>
    </item>
    <item>
      <title>LABORATORY TESTS ON SELECTED RAPID-SETTING REPAIR MATERIALS. INTERIM REPORT</title>
      <link>https://trid.trb.org/View/350831</link>
      <description><![CDATA[Many materials are available for rapid repair of portland cement concrete.  The report describes research which was undertaken to (1) investigate test procedures to evaluate rapid-setting repair materials and (2) test selected materials.  Report 311-1, "Results of a Survey on the Use of Rapid-Setting Repair Materials," summarizes the results of an initial survey which identified rapid-setting repair materials used in Texas and other states and summarized the properties and characteristics deemed most important.  This study examined a wide range of test procedures for evaluating rapid-setting repair materials, including compressive strength, modulus of elasticity, flexural strength, set time, flow, shear bond, flexural bond, and sand blast abrasion.  For some properties more than one test procedure was used.  Three materials were used in the testing program:  modified portland cement (Duracal), magnesium phosphate (Set-45), and magnesium polyphosphate (Neco-crete).  The tests which appear to be most applicable to evaluating rapid-setting materials are cylinder compression, flexural strength, Gilmore needle set time, and shear bond.]]></description>
      <pubDate>Tue, 30 Apr 1991 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/350831</guid>
    </item>
    <item>
      <title>NEW CHEMICALS SPEED CONCRETE REPAIRS</title>
      <link>https://trid.trb.org/View/348622</link>
      <description><![CDATA[This article provides some guidelines for selecting concrete repair materials, then discusses one of the best-known of the new repair materials--magnesium-phosphate based chemical-action concrete.  Magnesium-based repair materials are formulated to produce an exothermic reaction when mixed with water.  Composed of a blend of magnesium oxide and ammonium dihydrogen phosphate, different mixtures are often available for use in various weather conditions, including "hot-weather" formulas which contain a special integral retarder to ease work in warmer temperatures.  Faster repair times and lower traffic control costs offset the slightly higher cost of these materials.  Guidelines to be followed when using these magnesium phosphate-based materials are outlined.]]></description>
      <pubDate>Fri, 30 Nov 1990 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/348622</guid>
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