Adhesion in tension of polymer cement mortar by curing conditions using polymer dispersions as cement modifier

Abstract

In recent years, polymer cement mortars using polymer dispersions have been widely used as finishing and repairing materials in the construction industry, because of their excellent properties compared with plain cement mortar. In particular, polymer cement mortar’s superior adhesion to that with plain cement mortar and concrete has attracted a great deal of attention from researchers, who have developed a number of unique applications for improving adhesion. The adhesion behavior between polymer cement mortar and substrate at the interface is known to be important for the improvement of adhesion of polymer cement mortar as a repair and reinforcement materials. This research was experimented on the mix designs and curing methods that affect the behavior of these interfaces. I want to present not only optimum mix design but also optimum curing condition of polymer cement so that construction workers will be able to use it properly as special material related to RC structure on site. The purpose of this study is to evaluate the effect of curing conditions on the adhesion in tension of polymer cement mortar to cement concrete substrate compared, with plain cement mortar. Polymer cement mortars using three polymer dispersions with various polymer-cement ratios are prepared and tested for the adhesion in tension of specimens subjected to four curing conditions: standard, dry, water, and under high temperature. The test results show that the adhesion in tension of polymer cement mortars increases with increasing polymer-cement ratio, irrespective of the polymer type and curing conditions, and it is the highest under standard curing. The polymer cement mortars have high adhesion in tension in the order ethylene–vinyl acetate (EVA) > styrene-butadiene rubber (SBR) > styrene-vinyl acrylic ester (SAE). The failure modes of specimens under conditions I and II and at high P/C of 15–20%, which showed high adhesion in tension, revealed relatively high S ratios, indicating cohesion failure of the base concrete. It is apparent from this study that the adhesion in tension of polymer cement mortars is considerably influenced by the curing condition, polymer-cement ratio, and type of polymer.