Changes in the structural and phase composition and strength characteristics of concrete during liquid corrosion in chloride-containing media

Abstract

Abstract The results of physico-chemical studies that allow us to judge the changes occurring in the cement stone under the influence of liquid chloride-containing media are analysed. Samples of CEM I 42,5N Portland cement with a water-cement ratio of W/C = 0,3 were exposed to solutions of 2 % MgCl 2, 0,001 % HCl and 0,1 % CaCl 2 for 150 days. Changes in the strength characteristics of CEM I 42,5N Portland cement samples under the influence of chloride-containing media were studied. It is established that the 2 % MgCl 2 solution is an extremely aggressive medium in the conditions of liquid corrosion of concrete, its action causes a deterioration in the strength characteristics of concrete by 1,5 times. The changes in the structural and phase composition of concrete that occur under the influence of chloride-containing media are studied. The relationship between the characteristics of the cement stone structure and the strength parameters of the cement stone is established. The decrease in the strength of cement concrete is associated with the decomposition of calcium hydrosilicate C 2SH under the influence of liquid aggressive chloride-containing media, as evidenced by the decrease in intensity and the disappearance of the lines corresponding to this compound on X-ray images.