Early-strength development of blended concrete under different curing conditions

Mineral admixed or blended concretes require more time to attain the desired strength. The present investigation proposes new techniques for enhancing the early-strength development of blended concrete by implementing various thermal curing conditions for blended concretes. Blended concrete of grade M₄₀ was produced incorporating fly ash and ground granulated blast-furnace slag (GGBS) as partial replacement for ordinary Portland cement (OPC). The replacement levels of fly ash and GGBS were 20, 25 and 30% by weight of OPC. The effect of thermal curing conditions on blended concrete properties was evaluated by compression tests and split tensile strength tests. It was observed that the blended concrete required a minimum curing period of 56–90 d for attaining the desired strength. Under different thermal curing conditions, the desired strength can be achieved within a short duration of curing with the optimum dosage of fly ash and GGBS replacement in blended concrete.