The Influence of Combined Application of Two SCMs on the Corrosion and Acid Attack Durability of Mortars

Abstract

The improvement of the durability of cement-based materials(mainly mortar and concrete) is a very significant task, becausethese are the most frequently used building materials. Unfortunately,the environmental effects (acidic rain, chloride ions,sulphate ions, fermentation reactions, etc.) can cause damageson these structures. The (combined) application of differentsupplementary cementing materials (SCMs) is one possibilityto solve this problem due to their special properties (pozzolanicactivity, filling effect and influence on the hydrationmechanism). In this recent research metakaolin and silica fumewere used as SCMs and the influence of combined applicationof them was also studied. The permeability of the specimenswas investigated by chloride ion diffusivity, and the resistanceto harmful circumstances (sulphuric acid, pH = 1; acetic acid,pH = 3) was followed by measuring the change in mass upto 390 days. The aim of this research was to expose the maincharacteristics of the combined application of SCMs primarilyin acidic circumstances.