INFLUENCE OF SORGHUM HUSK ASH AS MICRO-FILLER IN POLYMER CONCRETE

Abstract

Polymer concretes (PCs) are known to be less permeable to water, but its usage is less popular in tropical countries like Nigeria because its common binder, thermoset resins, are very sensitive to rising temperature. This sensitivity to temperature accelerates the polymerization process and this jeopardizes its early strength development, thereby producing a PC with low workability and high porosity. To address this, polymer inhibitors with addition of Methyl Methacrylate (MMA) was introduced. Firstly characterization work on binder formulation was carried out by introducing Methyl Ethyl Ketone Peroxide (MEKP) and cobalt Naphthenate (CoNp) into the polyester resin as accelerators. Properties like density, specific gravity, particle size distribution, surface area, morphology and chemical composition were carried out on fillers. Sorghum Husk Ash (SHA) and calcium carbonate (CaCO3) were added as fillers. PC with optimum mix proportion at low binder (11%) and different filler contents (12, 14/ & 16%) were investigated under compressive test. Two types of PC (PC-SHA and PC CaCO3) with polyester binder were produced and its physical and mechanical properties were tested. PC-SHA gave highest compressive strength (56.6N/mn2 ) at 14% filler contents and least water absorption of 0.26% at 16% filler contents after 28 days as compared to compressive strength value of PC-CaCO3 (49.8N/mm2 ) and water absorption of 3.1% at 16% filler contents after 28 days. Conclusively, SHA is seen to be highly promising filler for PC after being modified by grinding.