Influence of Curing Temperature on Strength Development of Concrete

Abstract

With the aim to test the applicability of the commonly used maturity concept introduced by Freiesleben et al [1] to modern concrete and to investigate the impact of the curing history on the compressive strength of laboratory samples cured at elevated temperatures, four concretes with different binder compositions (a pure CEM I 42.5N, CEM I 42.5N with fly ash, CEM I 52.5N with fly ash and a CEM III/B) were cured and tested at temperatures ranging from 5 to 60 °C.To test the maturity concept, the development of the compressive strength of samples cured at temperatures ranging from 5 to 60 °C were tested at maturities ranging from 1 to 28 days.To test the impact of curing history at elevated temperatures on the compressive strength, concrete samples were cured at 60°C using two different temperature scenarios: (1) at a constant temperature of 60 °C and (2) at gradually increasing temperature from the casting temperature to the maximum temperature of 60 °C.It was found that the commonly used maturity concept is still applicable to modern concrete although the activation energy is dependent on the binder composition. Concerning the impact of curing history it was found that at 28 days of maturity, the strength of concrete cured at constant temperature of 60 °C was significantly lower than that of concrete cured at 20 °C. For the concrete exposed to gradually increasing temperature up to 60 °C, only a slight decrease in strength was observed for the pure cement concretes while the strength of the binder systems with fly ash increased.