The design of optimum composition for skimcoat cement using mixture experiment (case study of PT.X)

Abstract

The purpose of this research was to obtain the optimum composition of cement mixture skimcoat., cement skimcoat is a building material used to polish concrete building walls made of 2-3 mm thick, as an indicator of the quality obtained from the company is shown by compressive strength, with a range of 7-10 N / mm². to obtain the indicator, the mixture of scimcoat cement consists of three stages, first stage / mixed one with a mixed material : water, latex and pigment, the second stage / mixture of two with the ingredients : white cement, CaCO₃ and fine aggregate, for the third stage / mixture of three is composed of a mixture of one, a mixture of two and a polymer. the method used in this research is mixture experiment. where the experimental point is obtained by the formula of randomization 2^p-1 and three repetitions so that each trial consists of 21 experimental points.The optimum composition obtained for one skimcoat cement sack weigthing 30 kg is comprised of water of 21.91%, latex 2,6%, pigment 1,78%, white cement 15,12%, CaCO₃ 2,41%, fine aggregate 27,58% and polymer 2,5 %