Curing optimization for strength and durability of silica fume and fuel ash concretes under hot weather conditions

Abstract

This paper reports the influence of hot weather conditions and subsequent curing requirements on the strength and durability of multi-cementitious concrete. Five curing schemes were considered using persistent moist curing for various ages followed by exposure to natural hot weather conditions. It was observed that curing in hot weather tended to increasethe initial strength of ternary blended concrete for up to 28days; however, the development of long-term strength had insignificant effect. Binary blended concrete with silica fume (SF) exposed to hot weather have higher early age strength development compared to those under standard curing. The compressive strength and permeability of concrete was more sensitive to hot weather curing at an early age as its fly ash (FA) content increased. However, the effects of curing age diminished with high FA content and the susceptibility of long-term strength to hot weathering decreased as SF content increased. The porosity of concrete cured with continuous moistening was lower compared to those under hot weathering. The chloride permeability of binary blended concrete containing SF was less affected by hot weather curing. Using numerical models, it was found that the optimized persistent moist curing age for concrete without SF was dependent on target strength and durability requirements.