Influence of the relative molecular mass of viscosity enhancers on chloride diffusion in mortars: a preliminary study

Abstract

Chloride diffusion in concrete is one of the key parameters of durability design for structure. Existing methods of reducing the chloride diffusion such as decreasing water-cement ratio and adding mineral admixtures often lead to increase the risk of concrete cracking. In this study, we focused on mitigating the permeation of chloride ions in concrete by adding viscosity enhancers to improve the viscosity of concrete pore solution, without densifying the pore structure of concrete. A comparative study was conducted among the conductivity of KCl solutions with the addition of polyethylene glycol (PEG) with 11 different relative molecular masses. The results show that the chloride diffusion can be most effectively reduced when the relative molecular mass remains in the range of 400-1500