Potential of Starch as Organic Admixture in Cementitious Composites

Abstract

A durable, high-performance concrete is important for sustainable construction. Organic admixtures, a fair contender against its traditional chemical counterpart, is being explored in response to the renewed interest in the production of green concrete. In this study, two types of starch, i.e., laboratory starch and arrowroot, were used as admixtures and their effects on different properties of cement paste and mortar were observed. Starch showed a considerable retarding effect without adversely impacting the compressive strength. Also, it increased the flow of cement mortar substantially. The mortar samples with starch also exhibited a reduction in water absorption. A small amount of starch admixture, ranging from 0.5% to 2.5% of cement content by weight, has been found to increase the flowability and setting time of cement mortar keeping the strength, durability, and shrinkage parameters within an acceptable range. Within the scope of this study, 1%–1.5% starch addition by weight of cement exhibited improved performance in terms of setting time and flow.