Predictive Models Development to Optimize the Compressive Strength and Water Absorption of Palmyra Fibre-Reinforced Concrete

Abstract

In this paper, predictive models were developed to optimize the compressive strength and water absorption of palmyra fibre reinforced concrete using face centered central composite design of response surface methodology. Design factors; curing period and
fibre content at -1, 0, 1 coded level were adopted. The concrete mix proportion was designed to achieve minimum characteristic strength of 20 N/mm2 at 28 days curing period. Thus, concrete test specimens were produced with fibre content varied at 0.5, 1
and 1.5 % respectively by weight of cement. The concrete test specimens were cured at 7, 14 and 28-days hydration period. Compressive strength and water absorption tests of the fibre reinforced concrete was conducted after each curing period. From the
experimental results obtained, full quadratic model was chosen for estimating the performance of the reinforced fibre concrete with respect to the design factors and analysis of variance (ANOVA) was applied to determine the influence of model parameters and their interactions. The parameters were optimized by maximizing compressive strength and minimizing water absorption using desirability function approach. The optimum settings of parameters are the curing period and fibre content for maximizing compressive strength and minimizing water absorption. The water absorption has desirability of 0.56505 and the compressive strength has desirability of
1.000. The overall desirability index for the responses is 0.87659 at compressive strength of 22.12 N/mm2 and water absorption of 2.33% for concrete with 1.5% fibre content coded at 1.0 and 28-days curing period coded at 0.72.