Corrosion of reinforced concrete made with different binders and exposed for 20 years in natural sea water

Abstract

The investigation studied the effect of chloride penetration on different concrete cover depths. Ordinary Portland cement was used in all the concretes with different binder cement contents of 300 and 400 kg/m3. The specimens were cured in a chamber at 100% RH for 60 days, and then were immersed in natural water and finally they were placed in a tank with natural Mediterranean Sea water. Subsequently, Ecorr and Icorr measurements were performed periodically in order to characterise the corrosion response of the reinforcing steels. From their representation with time it can be derived when the steel bar starts to corrode and how it evolves with time, however due to the corrosion rate changes with temperature and with the evolution of the corrosion itself, the corrosion rate may not be clear enough to be used for comparative purposes. The accumulated corrosion better represent the corrosion process, a is used for making the comparison. The present work reports on the initiation and propagation periods of the different concrete mixes and shows the beneficial effect of the blending material and the short initiation times in OPC concretes with thin concrete covers.