Optimization Model for Compressive Strength of Sandcrete Blocks

摘要

Shelter is one of the basic infrastructural facilities that man needs for good living. Sandcrete blocks are composite materials made up of cement, sand and water moulded into different sizes. The compressive strength and other properties of sandcrete blocks are dependent on the mix proportions of the various components. This paper reports the results of formulation of optimization model for compressive strength of sandcrete blocks. A mathematical model was developed and used to optimize the mix proportion that will produce the maximum compressive strength of sandcrete hollow blocks using Scheffe's simplex lattice design approach. The three component second degree (3, 2) model as formulated compared favourably with the experimentally observed values. It also satisfied the student's t-test at 95% confidence level. The optimum compressive strength predicted by the model is 5.75 Nmm~(-2) corresponding to a mix of 0.524: 1: 5.04 for water: cement: sand ratio.