Acidic attack of cement-based materials—a review Part 2. Factors of rate of acidic attack and protective measures

Abstract

This paper shows that both the aggressivity of an acidic environment and acidic resistance of cement based materials are of a complex nature. Both depend on several conditioning factors. Therefore, the evaluation of the aggressivity of the environment only on the concentration of the aggressive species is entirely unsatisfactory and incorrect. On the other hand, even the evaluation of the acidic resistance on the cement used is inadequate. Therefore, further factors should be taken into consideration, conditions like the action of the aggressive medium on cement based material and the processing factors, e.g. w/c used, curing mode and others, conditioning the resistance of cement based materials. The various possibilies of protecting cement-based materials are considered. These are based on the optimal choice of the composition of the mixture, its consolidation and curing, aimed at ensuring maximal density and minimal permeability of the hardened material. A further possibility represents the application of surface coatings. The most effective way seems to be the preparation of materials on binders of new generation ensuring the compatibility with the acidic environment.