Basic studies on simplified curing technique, and prevention of initial cracking and leakage of water through cracks of concrete by applying superabsorbent polymers as new concrete admixture

Abstract

Recently, many kinds of superabsorbent polymers were developed. In this research, three special applications of the polymers, that is 1) application for simplifying curing of concrete at early age, 2) application for preventing cracking of concrete caused by initial drying shrinkage, and 3) application for preventing leakage of water through cracks, were proposed. The superabsorbent polymer used for this study can hardly absorb alkaline water in fresh/hardened concrete, but can absorb much neutral/acid water and makes gel. Thus when the neutral water is poured on concrete only once after setting, face of the concrete can be coated with the gels, and the concrete can be kept without drying, so that the 1) effect can be achieved. The water confined in the superabsorbent polymer and gels may delay the immediate drying of concrete, and the 2) effect may be obtained. The some of polymers around cracks can catch much neutral or acid water passing through the cracks and the gels fill up the cracks, so that the 3) effect can be achieved.