IMPROVING HYDRATION TIME AND COMPRESSIVE STRENGTH OF ETHYLENE-VINYL ACETATE POLYMER-MODIFIED CEMENT USING EGGSHELL ASH

Abstract

Polymers added to cement to enhance its physical properties retards its hydration reaction and reduces its compressive strength. Eggshell ash added to polymer-modified cement to enhance its physical properties can accelerate its hydration reaction and increases its compressive strength. Also, this study presents a simple way of recycling Ethylene-vinyl acetate polymer and eggshell wastes as a constituent in a mix of lightweight mortar and to evaluate its efficiency to produce a mortar with high strength and lightweight. The mechanism of improving the physical properties of polymer modified cement composites using an eggshell was investigated by setting time, com pressive strength test, and X-Ray diffractometer with various ratios of (15%, 30%, 45%, 60%) eggshell to polymer-modified cement. It is found that increasing the amount of eggshell caused an acceleration in hydration reaction and an increase in compressive strength. The initial and final setting time which is found in a polymer –cement composite was 261 and 403 minutes respectively, the incorporation of 60% eggshell ash with polymer-modified cement reduced the time to 222 and 356 minutes respectively. The 7th and 28th day compressive strength of Polymer-cement compo site was 3.39 MPa and 6.5Mpa respectively, this was improved to 4.84 MPa and 7.87 MPa respec tively, and this is fulfilled by incorporation of 60% of eggshell ash with the Polymer- cement composite. From an XRD result, it is found that the intensities of Ca(OH)2 peak at an angle 2theta = 180 and 470 increased with the increase in eggshell ash. The increase in yield of calcium ions reduces retardation in a hydration reaction.