Effect on Structure and Properties of Cement-Based Materials by Polymer-Modified Metakaolin Slurry

Abstract

It is not easy to disperse metakaolin in the cement concrete uniformly. The reunite phenomenon caused by lamellar structure and fine particles can reduce the properties of concrete. The fluidity of mortar were studied by recombining polyethylene glycol (PEG), sodium methyl-dinaphthalene sulfonate (NNO) and hydroxyethyl cellulose (HEC) with the metakaolin slurry, and then the internal structural properties of the different cement-based materials were analysed. The experimental results showed that when the ratio of MK and H2O was 35 : 65, the metakaolin slurry could reduce the adverse effect of metakaolin on the fluidity of mortar to a certain extent. The slurry prepared by P1N2H2, P2N1H2 and P2N1H1 composite dispersant dispersed more uniformly in the mortar than other groups. The hydration caused by these types of slurry during cement formation consumed Ca(OH)2 crystals sufficiently, which led to generating more dense C-S-H gel structure in the final cement-based materials.