Predicting product parameters of fly ash–cement–sand bricks

This paper discusses models with ternary systems of fly ash, cement and sand by using simplex lattice and simplex centroid designs for building bricks. A statistical design with upper and lower bounds of three component mixtures was adopted to select the mixture proportions of experimental points required for prediction of the product parameters, namely compressive strength, bulk density and water absorption of cement fly ash bricks. The experimental points include the process parameters such as percentages of fly ash, cement and sand and the corresponding product parameters at different curing periods. Regression models of various orders for the above design methods are developed. Various tables and graphs are incorporated to give the results and comparisons among experimental and theoretical models. The developed model may be useful for direct prediction of product parameters using a smaller and fixed number of design points.