A Mathematical Model for Predicting Autoclave Expansion for Iraqi Portland Cements

Abstract

The autoclave expansion test (ASTM C151- 05) is one of the internationally used tests in detecting the unsoundness of Portland cements. The factors affecting test results were reviewed. A statistical analysis of 130 autoclave test results was done. Each result represents the average of a month production, for four Iraqi cement factories. Based on that, a mathematical model was built to predict the autoclave expansion for Iraqi Portland cements. The coefficient of determination, R2, was 0.97. The model was tested with new raw data and the predictions were highly correlated to the experimental results (r = 0.92). Moreover, a t-test was carried out and it showed that there is no difference between means of experimental and predicted sets of values. The good predictions give the chance to make use of the model in saving time and money.