Maturity Method Evaluated for Various Cementitious Materials

The maturity method accounts for the effect of curing temperature on the strength development of well-cured and consolidated concrete. This paper describes an investigation of the accuracy of the maturity method to estimate the strength when different cementitious systems are used. Mortar cubes, made from Type I cement and various replacement levels of Class C fly ash, Class F fly ash, and ground-granulated blast-furnace slag, were cured at isothermal curing temperatures of 8, 23, and 40°C. The amount of long-term strength reduction, due to curing at high temperatures compared with curing at room temperature, is influenced by the type of cementitious system used in the concrete mixture. Based on the strength results of these mortar cubes and the procedure outlined in ASTM C 1074, datum temperature and activation energy values were determined for these cementitious systems. The ability of the equivalent age maturity method to accurately estimate the strength is significantly influenced by the composition of the cementitious material system.