Abstract
Strength test results for accelerated-cured specimens, obtained after only 24 h, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the uncertainty of their predictions and the stability of the relationship between their 24 h and 28 day concrete strength. The results suggest that warm water accelerated curing is preferable to hot water accelerated curing of concrete. Various methods for reducing the uncertainty associated with the estimates of 28 day strengths are suggested. In particular it is suggested that the effect of variations in cement chemistry over time be addressed by using dynamic linear models with coefficients that vary over time.