Acid attack on hardened cement paste by acids forming low soluble calcium salts

25th International Conference and Meeting of Departments, CONSTRUMAT 2019

Pavlík, V.^1

Slovak University of Technology, Faculty of Civil Engineering, Department of Material Engineering, Radlinského 11, Bratislava

810 05, Slovakia^1

关键词: Calcium salts;    Cement matrix;    Corrosion effects;    Corrosion products;    Diffusion resistance;    Hardened cement paste;    Rate of corrosions;    Strong acids;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/549/1/012020/pdf
DOI  :  10.1088/1757-899X/549/1/012020

来源: IOP

【 摘 要 】

Solutions of acids have very aggressive effect on the cement matrix in concrete. Aggressiveness of the solutions increases with concentration of an acid but also depends on the acid type. The corrosion effect of solutions of various types of acids and their mixtures on hardened cement pastes is described in the paper. The results confirmed, that the rate of corrosion of hardened cement paste in solutions of strong acids (HCl, HNO3) was faster than in solutions of weak acids. However, the rate of corrosion of hardened cement paste was lower in solutions of acids that produce low soluble calcium salts, because calcium salts filled the pores in the layer of corrosion products and thus increased its diffusion resistance.