Effect of Curing Age on High-Strength Concrete at Low Temperatures

Abstract

This investigation deals with the effect of curing age on the strength development of high-strength concrete containing silica fume and fly ash and exposed to cold temperatures. Tests were performed on three sets of specimens, having initial curing ages of 1, 14, and 28 days at room temperature. The test specimens were exposed to five temperatures varying from −10°C to 20°C for periods over 3 months in cold ocean water. The gains in compressive and tensile strength with time were found to be directly proportional to the temperature increase. The highest gain in strength with time was recorded at 20°C and the lowest at −10°C for all three sets of specimens. For the set initially cured for 1 day, the reduction in the rate of strength gain was profound. However, it was minor for the set cured initially for 14 days, and negligible for the set cured initially for 28 days. A maturity analysis using a hyperbolic function was performed. The maturity functions gave reasonable agreement with the three sets of specimens at different temperatures except for the specimens cured for 1 day and exposed up to 7 days.