One common aggressive mechanism acting in reinforced concrete is chloride attack which induces steel corrosion. Although it has mostly been studied and analyzed separately it has been observed that loads acting on concrete may modify the deteriorating effect.
In this research the effect that combined attack provokes on concretes made of ordinary Portland cement (OPC), high sulfate-resistance cement (SR) and blast furnace slag (BFS) cement is investigated. Five mixes were made with these materials, 2 of them using a type 52.5 N (OPC) cement, 2 replacing OPC by 50 and 70 % of BFS and 1 made of 52.5 N (SR) cement type. Cubic samples made with all binder types were exposed to a 3% by weight sodium chloride solution while applying a permanent splitting tensile load corresponding to 50 % of their breaking capacity. Prismatic samples (100 x 100 x 400 mm) made of OPC binder were exposed to a 3% by weight sodium chloride solution while maintaining a compressive load equal to 30 % of their maximum capacity. After the exposure time, ground layers were obtained from the samples to determine the chloride ingress into the concrete by means of potentiometric titration. To define chloride transport in concrete an error function solution was applied to Fick’s second law.
In terms of their diffusion coefficient and chloride surface concentration in decreasing order of performance were found: the concrete with 70 % replacement by BFS, followed by the concrete with 50 % BFS substitution, then pure OPC concrete and finally the sulfate resistant cement concrete.
Load levels of 30 % in compression and 50 % in splitting tensile testing, improved the resistance of concrete to chloride attack
