ARROWROOT AS AN ORGANIC ADMIXTURE FOR IMPROVED MECHANICAL PROPERTIES OF CONCRETE

This paper investigated for the first time the incorporation of arrowroot into concrete mixture to improve the mechanical properties of hardened concrete. Through a central composite design, the effects of the amount of arrowroot added, water-cement ratio, and curing time on compressive strength were studied using response surface methodology.  Results indicated that arrowroot content, curing time, interaction of curing time and water-cement ratio, and the squares of the three independent variables were significant factors and the behavior of the system followed a second-order model.  Optimized conditions were determined to be 1.68% arrowroot content (per weight of cement), 0.49 water–cement ratio, and 24 curing days for a theoretical compressive strength of 34.073 MPa. The optimized conditions were validated and the model was determined to have an accuracy of 97.21%.  The optimized concrete were then tested for compressive, flexural strength, split-tensile strength, modulus of elasticity, and shrinkage potential where test results showed improvements of 44.25%, 22.44%, 37.10%, 20.11%, and 96.30%, respectively, when compared with conventional concrete.  These results prove that the use of arrowroot as organic admixture greatly improved the mechanical properties of concrete.