Original paper(Vol.48 No.7 pp.783)

Abstract:Conventional epoxy-modified mortars and concretes have an inferior balance between applicability and cost performance due to the necessity of two-component mixing of epoxy resin and hardener and high polymer-cement ratio of 50% or higher. In addition, the pot life of the mixture of the epoxy resin and hardener is limited after mixing them. In this study, the latent-curing epoxy resin containing microcapsuled curing agent which does not react with the epoxy resin at normal temperature and starts a chain reaction at 80�� or more is used as a one-component epoxy resin for cement modifier. Epoxy-modified mortars using the one-component epoxy resins and conventional two-component epoxy resins are prepared with polymer-cement rations of 5 to 20%, and subjected to flexural, compression, water absorption, drying shrinkage tests at the curing periods of 28 days. In the preparation of the polymer-modified mortars using the latent-curing epoxy resin, the specimens of the mortars are heat cured under 80�� for polymerization at 2 days after casting. From the test results, the one-component latent-curing epoxy-modified mortars have good workability, high flexural and compressive strengths, ductility and resistance to water absorption compared to those of the conventional two-component epoxy-modified and unmodified mortars. The one-component latent curing epoxy-modified mortar can successfully be used for preparing thin precast products because of such superior properties and smaller drying shrinkage after heat cure.

Key Words:Polymer-modified mortar, One-component latent-curve epoxy resin, Two-component epoxy resin, Flexural and compressive strengths, Ductility, Water absorption, Drying shrinkage