EFFECT OF POLYMER ADMIXTURES ON MECHANICAL PROPERTIES OF PREPLACED AGGREGATE CONCRETE

Abstract

This research was carried out to study the influence of different polymer admixtures (PA) namely vinyl acetate-ethylene copolymer dispersion, styrene butadiene dispersion and styrene butadiene emulsion in preplaced aggregate concrete (PAC) on its fresh and hardened properties, and to identify the highest flexural strength of preplaced aggregate concrete using PAs.  Hypothesis was established as the higher the bonding among grout and aggregate surface, the higher the flexural strength.  Accordingly, aggregate-grout bond strength was studied at the introduction of various PAs by conducting pull-off tests to decide on the most effective PA at bonding and mix designs were chosen for hardened properties evaluation.  Fresh properties were checked to ensure the sufficiency in flow and to fix the quantities of all the contents in the grout mix.  Compressive strengths of grout and PAC were checked along with flexural strength to develop relationships on selected mix designs.  A control mix design without any PA and a past researcher’s mix design which gave the highest flexural strength using silica fume was considered for comparison purposes.  As a conclusion, vinyl acetate-ethylene copolymer dispersion performed better than the others in all aspects and the flexural strength was almost the same with the past researcher’s highest PAC strength obtained with silica fume.