Investigating effects of plant based polymeric material as a chemical admixture on properties of concrete

Abstract

Aqueous extract of okra called here as bio-admixture was tested for use as a sustainable chemical admixture in the production of cement mortar and concrete. Several fresh and hardened states properties of cement mortars and concrete with and without the presence of bio-admixture were evaluated. The influences of the mucilage on the setting time of concrete, the workability, as well as compressive strengths were investigated. Optimization experiments were run to establish the most optimum mucilage concentration for the mix. Results indicated that the investigated bio-admixture exhibits viscosity-enhancing property. In comparison to the reference mixes, bio-admixture as an admixture is more of a retarder. Evidently, the extract presented an increased rate of hydration; supposedly related with the interactions of pectin type hetero-polysaccharides present in bio-admixture with Ca2+ ions of cement paste. Compressive strengths of bio-admixture containing mortar and concrete are higher than that of the reference specimens at the investigated curing periods. Most of the properties of cement mortar and concrete are also dependent on the concentrations of bio-admixture in mix. Therefore, investigated bio-admixture can ably be considered as a low-cost, environmentally benign viscosity enhancing admixture for producing sustainable cement composites having improved mechanical and possible durability properties.