9 - Polymer-Modified Mortars and Concretes

Abstract

Polymer-modified mortar and concrete are prepared by mixing either a polymer or monomer in a dispersed, powdery or liquid form with fresh cement mortar and concrete mixtures, and subsequently cured, and if necessary, the monomer contained in the mortar or concrete is polymerized in-situ. Several types of the polymer-modified mortars and concretes— namely, latex-redispersible polymer powder-, water-soluble polymer-, liquid resinand monomer-modified mortars and concretes are produced by using the polymers and monomer. Of these the latex-modified mortar and concrete are by far the most widely used cement modifiers. Although polymers and monomers in any form such as latexes, water soluble polymers, liquid resins, and monomers are used in mortar and concrete, it is very important that both cement hydration and polymer phase formation proceed well to yield a monolithic matrix phase, with a network structure in which the hydrated cement phase and polymer phase interpenetrate into each other. In the polymer-modified mortar and concrete structures, aggregates are bound by such a co-matrix phase. The superior properties of the polymer-modified mortar and concrete to conventional mortar and concrete are characterized by such a distinct structure.