Properties of Polymer-Modified Mortars Using Epoxy Resin Without Hardener

Abstract

In the preparation of conventional polymer-modified mortars using epoxy resin, the use of any hardener has been considered indispensable for the hardening of the epoxy resin. The authors have noticed that the hardening of epoxy resin occurs in the presence of alkalis in cement mortar. Polymer-modified mortars using epoxy resin without any hardener are prepared with various polymer-cement ratios, and tested for strength, adhesion, water absorption, drying shrinkage, chloride ion penetration and carbonation. From the test results, the polymer-modified mortars using the epoxy resin without any hardener are made successfully, and have some superior properties compared with conventional epoxy-modified mortars. It is concluded that polymercement ratios of 5 to 10% are considered optimum for the preparation of such polymer-modified mortars.

Strength properties and molecular composition of epoxy-modified mortars

“…They are also used as an admixture in concrete to impart certain effects on mortars. However, the preparation of conventional polymer-modified mortars using epoxy resins cannot be realized without the use of hardener [1]. A previous study by Kakiuch [2] showed that epoxy resins can harden in the presence of alkalis whereby the authors succeeded in developing polymer-modified mortars using epoxy resin without any hardener.…”

“…A previous study by Kakiuch [2] showed that epoxy resins can harden in the presence of alkalis whereby the authors succeeded in developing polymer-modified mortars using epoxy resin without any hardener. The aforementioned application was countered by Ohama [3] who posited that epoxy resin without hardener, in concrete and mortar at ambient temperature has lower rate of hardening and strength. In order to overcome that problem, an autoclave curing and steam curing process was used to bring about early strength development of epoxy-modified mortar and concrete.…”

Studies on the Microstructure of Epoxy-Cement Composites

“…Ohama and his co-workers have first proposed and demonstrated that this process can proceed inside the cement paste [22], allowing for some specific features of epoxy-cement composites, like ability to partial self-repairing [23].…”

Review and discussion of polymer action on alkali–silica reaction

“…The higher pore volume compared to the unmodified mortar could also have increased either the volume of voids available to accommodate ASR expanding products or the leaching of alkalis away from the PCM specimens in the humid conditions, thus contributing to the observed reduced expansion. Epoxy-modified mortars have also been reported to have self-healing properties [35], which may contribute to an increased resistance to crack opening and thus to reduce expansion.…”