Effect of curing conditions on strength and durability of high-performance concrete

This paper describes the eects of variable curing temperatures on compressive strength and sulfate resistance of high-strength, high-performance concrete. Two dierent concrete mixtures were proportioned to attain the 56-day compressive strength of about 70 MPa upon moist-curing. One mixture contained more quantity of ASTM Class C y ash than the other one. For each mixture, one set of specimens was cured in a standard moist-curing room at 23C and 100% relative humidity; another set of specimens was sealed in plastic bags and cured in an elevated, Variable-Temperature Curing Environment (VTCE). The average temperature of the VTCE oscillated between about 30 C and 41 C once per day. This study revealed that the VTCE-cured concrete did not signi ficantly exhibit different comprehnssive strength or ability to resist sulfates attack compar ed to the standard moist-cured specimens. Thus, it was concluded, based on the results of this research, that additional effort to stabilize higher curing-temperatures would be necessary for eld-cured concrete.