Optimizing the Sulphates Content of Cement Using Multivariable Modelling and Uncertainty Analysis

This study aims at determining the effect of the cement composition and mortar age on the optimum content of sulphates using maximization of compressive strength as a criterion. Extensive experimentation has been performed to achieve this purpose by utilizing four cement types and measuring the strength at ages ranging from 2 days up to 63 months. Strength is correlated with the ratio of sulphates to clinker content, SO3/CL and moles SO3/ moles C3A. A generalized model correlating SO3, cement composition and curing time is developed, intensely indicating the necessity of placing the SO3 target within the optimum region and realizing it as well. The set of four equations involves polynomial and logarithmic equations correlating the variables. A variance analysis based on error propagation technique, proves that SO3 affects not only average value of strength but also its variability.