Applicability of the Maturity Method to High-Performance Concrete

摘要

The study examines whether the maturity method is applicable to represent thestrength development of high-performance concrete mixtures cured at different temperatures. Two mortar mixtures were investigated having water to cementitious solids ratios of 0.29 and 0.36. The mixtures were made with Type I cement, silica fume (10% by mass of cement), and a high-range water reducing admixture. Ten batches of mortar were prepared to make cube specimens, which were cured under water at three temperatures: 7, 23, and 40 C. Compression strengths were measured at ages ranging from 5 hours to 139 days. The strength-age data were analyzed using three models to determine the rate constant for strength development at each curing temperature. The models included two hyperbolic equations (linear and parabolic) and an exponential equation. The rate constant versus curing temperature relationship for each model was represented by a simple exponential equation, which was used to convert test ages to equivalent ages of curing at 23 C. The strength development of the various mortar batches could be described by a single equation relating relative strength to equivalent age. Thus it was concluded that the maturity method is applicable to describe strength development of the low water-cement ratio mixtures. It was also observed that the estimated long-term strength of the batches did not appear to be affected by the curing temperature. This is in direct contrast with the known behavior of conventional concrete mixtures.