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This paper examines the freezing and thawing resistance of high early-strength concrete (HESC) developed for rapid repair of pavements and bridge decks. The cement types chosen for this study included ASTM Type III, ASTM Type V, and Calcium Sulfoaluminate (CSA). A cement content of 386 kg/m 3 was maintained for all studied concretes. Specimens were tested after 24 hours and 28 days of curing in order to evaluate compressive and flexural strengths. In addition, the opening time was determined based on the required time to achieve the minimum compressive strength of 20.7 MPa. The freezing and thawing (F–T) resistance of the test samples were evaluated in accordance with the F–T duration of 96 hours per cycle for a total of 25 cycles. Test results revealed that at the opening time and after 24 hours curing, CSA cement concrete displayed the highest compressive and flexural strengths, but lowest resistance to freezing and thawing with de-icing salt. The 28-day cured Type V cement concrete produced the highest strength and de-icing salt resistance, while CSA cement concrete produced the contrary.

This study examines the suitability of ASTM Type V cement concrete for rapid repair applications. To this end, experimental results on transport and durability properties of high early-strength concretes using ASTM Type V cement were compared with those of a more traditional cement used for rapid repair, i.e. Type III cement. A cement content of 445 kg/m 3 (750 lb/yd 3 ) was maintained for all studied concretes. The experimental program included compressive strength, absorption, rapid chloride migration, corrosion resistance, and mass loss due to freezing and thawing regimes. The results of this study revealed that use of Type III and V cements were both effective for concrete rapid repair applications. The opening time to reach the minimum compressive strength of 21 MPa (3000 psi) was found dissimilar. Type III cement concrete showed better strength properties at early ages due to its high fineness. However, as curing age was extended to 24 hours and 28 days, Type V cement concrete produced higher strength results. Moreover, Type III cement concretes failed to display better performance in transport properties, corrosion, and frost resistance when compared to that of the studied Type V cement concretes.

This paper examines the abrasion resistance of high early-strength concrete developed for rapid repair of highways and bridge decks. The cement types chosen for this study included ASTM Type III, ASTM Type V, and Calcium Sulfoaluminate (CSA) cements. A cement content of 386 kg/m 3 (650 lb/yd 3 ) was maintained for all studied concretes. Test samples were tested after 24 hours and 28 days of curing in order to evaluate compressive strength and depth of wear. Test results revealed that the opening time to attain minimum required compressive strength for CSA cement concrete was one hour, whereas the values for Type V and Type III cement concretes were 8.5 and 6 hours, respectively. After 24 hours curing, CSA cement concrete displayed the highest strength, but lowest resistance to wear. The 28-day cured CSA cement concrete produced the highest strength and resistance to abrasion, while Type III cement concrete showed a similar strength, but lower resistance to wear, when compared to those of the Type V cement concrete.

Properties of high early-strength concretes (HESCs) containing Type V, Type III, and rapid hardening calcium sulfoaluminate (CSA) cements were investigated at curing ages of opening time, 24 h, and 28 days. Investigated properties included the fresh (workability, setting time, air content, unit weight, and released heat of hydration), mechanical (compressive and flexural strengths), transport (absorption, volume of permeable voids, water penetration, rapid chloride permeability, and accelerated corrosion resistance), dimensional stability (drying shrinkage), and durability (de-icing salt and abrasion resistance) properties. Test results revealed that the HESC containing Rapid-Set cement achieved the shortest opening time to attain the required minimum strength, followed by Type III and Type V cement HESCs. For the most part, Type V cement HESC produced the best transport and de-icing salt resistance, whereas Rapid-Set cement HESC displayed the best dimensional stability and wear resistance.

The aim of this research was to identify High Early-Age Strength (HES) concrete batch designs, and evaluate their suitability for use in the rapid repair of highways and bridge decks. To this end, two criteria needed to be met; a minimum compressive strength of 20.68 MPa (3000 psi) in no later than 12 hours, and a drying shrinkage of less than 0.06 % at 28 days after curing. The evaluations included both air-entrained, and non-air-entrained concretes. The cement types chosen for this study included Type III and Type V Portland cement and “Rapid Set”—a Calcium Sulfoaluminate (CSA) cement. In addition, two blended concretes containing different ratios of Type V Portland cement and CSA cement were investigated. The evaluation of the studied concretes included mechanical properties and transport properties. Additionally, dimensional stability and durability were investigated. Evaluations were conducted based on cement type and common cement factor. Fresh property tests showed that in order to provide a comparable workability, and still remain within manufactures guideline for plasticizer, the water-to-cement ratio was adjusted for each type of cement utilized. This resulted in the need to increase the water-to-cement ratio as the Blaine Fineness of the cement type increased (0.275 for Type V Portland cement, 0.35 for Type III Portland cement, and 0.4 for Rapid Set cement). It was also observed that negligible changes in setting time occurred with increasing cement content, whereas changes in cement type produced notable differences. The addition of air-entrainment had beneficial effect on workability for the lower cement factors. Increasing trends for peak hydration heat were seen with increases in cement factor, cement Blaine Fineness, and accelerator dosage. Evaluation of hardened properties revealed opening times as low as 5 hours for Type V Portland cement with 2.0 % accelerator per cement weight and further reduction in opening time by an hour when accelerator dosage was increased to 2.8 % by cement weight. When Type III Portland cement and Rapid Set cement were used, the opening time reduced to as low as 4.5 hours and 1 hour, respectively. The results for Type V Portland cement concretes showed that as cement factor increased so did mechanical properties until the cement factor exceeded 504 kg/m3 (850 lb/yd3), at which point the peak heat of hydration exceeded 46.1 °C (115 °F) and the mechanical properties decreased. Other evaluations on the studied High Early-Age Strength Type V Portland cement concretes revealed increases in absorption, rapid chloride penetration, water permeability, drying shrinkage, corrosion resistance, and resistance to wear with increases in cement content. The addition of air-entrainment had adverse effects on compressive strength, absorption, and rapid chloride migration; while showing lower values for rapid chloride penetration. Curing had positive effects on all hardened properties of the studied HES concretes containing Type V cement. When examining the studied Type III Portland cement concretes, it was seen that an increase in cement content led to decreases in mechanical properties. It is noted that the peak heat of hydration for these concrete exceeded the threshold of 46.1 °C (115 °F). In addition, increases in cement factor also resulted in decreases in rapid chloride migration, frost resistance and resistance to wear. Increases in cement content resulted in increases in absorption, rapid chloride penetration, water permeability, drying shrinkage, and corrosion resistance. The use of air-entrainment imparted decreases in compressive strength and rapid chloride penetration, increases in absorption, and negligible effects on rapid chloride migration. Extending curing period resulted in beneficial effects on all properties of the studied Type III cement concretes. The studied CSA cement concretes had slightly decreasing strength trends as cement content was increased. Concretes containing CSA cement produced the lowest opening time (one hour) and the highest peak hydration heats of all concretes studied. While its corrosion and frost resistance reduced as cement content increased, the absorption and rapid chloride penetration increased with increasing cement content. For drying shrinkage, opening time curing showed more volume change with increasing cement content, whereas extending curing to 24 hours and 28 days resulted in reduction of drying shrinkage. Increasing cement factor had minimal effects on water permeability and abrasion resistance. Air-entrainments reduced compressive strength, but increased absorption and rapid chloride penetration. Rapid chloride migration was found to be incompatible with CSA cements concretes. All hardened properties of the studied CSA cement concretes improved once curing age was extended to 24 hours and 28 days. (Abstract shortened by ProQuest.)