The Effect of Surfactant and Alkali on the Surface Tension of Simulated Solutions of Alkali Activated Slag Cement System

Abstract

Alkali activated slag cement and concrete are high strength, rapid hardening, low heat of hydration, good durability and so on. Whereas, too high viscosity and bad workability of the fresh mixture is the crux of the matter to embarrass application of alkali-activated slag cement and concrete. Development of special superplasticizer for alkali activated slag cement and concrete is a worth exploring way to solve the problem, and the study on the surface tension of simulated solutions of alkali activated slag cement system is one of the basic researches about the special superplasticizer. In this paper, the surface tension of surfactant-alkali-water was studied by Wilhelmy method. The results showed, first, water-glass had the best efficacity of several alkali activators, when the modulus of water-glass was 1.5 and dosage of water-glass by Na2O was 8%, the surface tension was reduced by 33 mN/m and reduced to 39.9mN/m; second, [CH3(CH2)9]2N(CH3)2Cl had the best efficacity of several surfactants, when the concentration of [CH3(CH2)9]2N(CH3)2Cl was 50g/L, the surface tension was reduced by 35.3 mN/m and reduced to 32.5 mN/m; finally, the effect of surfactant and alkali together on the surface tension of water was complex, surfactants had hardly effective in water glass.