Evolution of microstructure and mechanical behavior of concretes utilized in marine environments

Concrete in marine environments is exposed to chemical mechanisms of deterioration, most of them involving chloride and sulfate ions. The principal motivation of this study is to try to minimize the expansive reactions between the aggressive ions and the cement matrix. However, the most effective protection will undoubtedly be the one that prevents the penetration of aggressive substances. The ingress of any aggressive substance in concrete is determined by concrete’s porous structure, especially the accessible connected porosity. This porosity is defined by the composition of the concrete and the chemical characteristics of the cement. The results clearly show that concrete that includes silica fume is significantly less porous and less permeable. In the rest of the mixtures studied, the porosity is higher, and the pore radius is the most decisive factor in defining the permeability.