The Mechanism of a Penetrative Action for Portland Cement-Based Waterproofing Compositions

Abstract

Theoretical and experimental investigations of the studies of the mechanism of a penetrative action of waterproofing compositions have been carried out. It was theoretically justified that the mechanism of penetration of the salts of the complex chemical additive of analyzed mixture into the concrete (mortar) of the structure carried out according to the diffusion mechanism. The diffusion of the salts of the complex chemical additive into the concrete with different porosity was calculated theoretically. For the water-saturated noncapillary pores after two hours diffusion depth attains 9 mm, and after three hours it is already 14 mm; for the loose concrete it occurs at a slower rate and after 1 week its depth attains 3 mm; for the dense concrete after 2 weeks it is within 0.2 mm. It was experimentally confirmed that the salts of the complex chemical additive included into dry Portland cement-based mixtures penetrate the loose concrete with the water resistant less than W2 the depth of 5 to 10 mm, and it results in the colmatation of the porous space with the crystal hydrates of AFm- and AFt-phases at the same depth.