Performance of steel in ordinary Portland, fly ash and slag cement mortars during the hydration period

Durability of steel embedded in concrete is an area, widely investigated, especially in salt laden environment. Besides several other preventive measures the use of pozzolan and slag cements have been propogated for a better service life due to their fine size and electrical resistivity. The studies are, however, oriented around the long-term performance of steel in a certain period of time. The long-term performance of steel is, nevertheless, quite dependent upon the conditions of hydration which is generally ignored when the durability studies are conducted. The present paper focuses upon the corrosion resistance of steel, embedded in ordinary Portland, pulverized fly ash and blast furnace slag cement mortars containing chloride as an admixture, and also mortars free of chloride, but immersed in chloride contaminated environment, especially investigating the behaviour during the hydration period utilizing the potentiostatic polarisation resistance technique. The effect of mix proportions has also been contemplated to ascertain the durability under the simulated conditions of adverse exposure during the hydration period, which ultimately determine the durable service life of a concrete structure.