Development of compressive and tensile strength of hsc under steam curing using the maturity approach

Abstract

Steam curing of concrete is widely used in the concrete industry nowadays. Under steam curing, the concrete is subjected to high temperatures for a short period of time. Compressive and tensile strength are accelerated, and thus much higher strengths at early ages were achieved. The influence of curing temperature on the development of mechanical properties of concrete can be estimated by the maturity approach. Maturity functions of time and temperature are used to transform actual times in equivalent ages at a reference temperature. This investigation uses the maturity approach to assess the influence of steam curing in high-performance concrete with various dosages of silica fume addition (0%, 10%, and 20% of cement mass). A 6-hour steam curing period at 80°C was applied, with compressive and tensile strength of the concrete mixtures evaluated every hour. The characterization of the thermal sensitiveness of every mixture was performed according to ASTM C 1074. The apparent activation energies of mortar mixtures with the same sand-cementitious ratio as the concrete mixtures were obtained from the development of compressive strength at three isothermal conditions at 30°C, 55°C and 80°C. The results obtained permit an evaluation of the applicability of the maturity approach to steam-cured high strength concretes. The influence of silica fume addition levels on the development of compressive and tensile strength of steam-cured HSC was also investigated.