Compressive Strength in Sulphate Resisting Portland Cement (SRPC)

Abstract

The compressive strength of cement is regarded as a principal indicator to determine the quality of cement. Therefore, efforts were focused to combine the factors which affect compressive strength together in such a form to develop suitable statistical models for predicting strength of cement at various ages (3 and 7 days). Using SPSS16 software, a statistical analysis is performed for (574) observations taken from archive of quality control at Kerbala Cement Plant, which produces low alkalis sulphate resisting Portland cement. These data sets include compressive strength at 3 and 7 days with various independent variables. Stepwise regression results in multiple linear models that explain (99.7 %) and (99.9 %) of variations in 3-days and 7-days compressive strength respectively in function of; C3S, C2S, C3A, SO3 contents, and Insoluble residue (IR). The developed models show that these contents positive effect on strength, but (I.R) content has a negative one. Such models could be used in quality control of SRPC factories to enable the manufacturer to make corrections in process within production stage. The sufficient data used in the analysis assures confidence of the developed statistical model.