Author : Khudair Jassim, Majeed
journal of kerbala university,
2013, Volume 9, Issue 0, Pages 31-37
It is impractical for cement producers to test the produced cement after manufacturing process, because it is very difficult to correct the final production. Moreover, it is useful to make adjustment to the raw mix design through the blend process of raw materials.
Calcium sulphate is added in small quantities to the other constituents of cement during its manufacture to control the setting time of the product.Using a large scale data base, this paper shows an effort to model optimum sulphate required to be expressed in term of some concerned variables.
Statistical analysis using SPSS16 software is performed for a data base of 362 chemical and physical tests obtained from archive of quality control at Kerbala plant for SRC cement. These data sets are refined to 322 by excluding outliers to avoid errors in measurement, recording, and observations.
Stepwise regression results in a linear model that explains (99.8%) of variation in required sulphate in relation with: C4AF, C3A, and K2O, while excluding one explanatory variable (Na2O) according to a degree of significance of (0.05).The developed model can be used as a guide for manufacturer to control the content of; K2O, C3A, and C4AF that result in an optimum sulphate content of SRC cement.