The use of fly ash as supplementary cementitious material was originally motivated by its consistent pozzolanic activity and provide for sustainable development in the cement industry. However there is now a growing acceptance that the fly ash blended cements provide several distinct advantages because of which they can be recommended on their own merit. The improved understanding of the beneficial properties imparted by fly ash for both the plastic and hardened stage of blended cement concrete has led to several contractors specifying the use of fly ash based cements for their projects. The enhanced durability of blended cement concretes has made it the preferred cement thereby replacing the earlier skepticism regarding its performance.
It is now beyond doubts that in the Tropical climatic condition of the country, Blended cement concrete either with the blending component as a part in cement or alternatively as site blended at the Ready – Mix locations, is the option for a durable civil structure.
This paper illustrates in some detail, a comparison of the properties of the fly ash based blended cement concrete and Ordinary Portland Cement (OPC) concrete. Based on the observed & reported data on the effect of use of low lime class-F fly ash (Grade I) based cement / concrete on the properties of the concrete, the authors make an attempt at evolving an understanding on influence of the fly ash component in determining the limiting / favoring conditions for improved properties related to durability of the concrete such as resistance to reinforcement corrosion, resistance to sulphate attack and resistance to expansion due to ASR reaction.
The understanding of the possible mechanisms of concrete deterioration has been useful to tailor-make the properties of PPC (fly ash based) for improved performance of resultant concrete. The paper was presented at conference in Mumbai IIT