Effect of Curing Methods on Fly Ash based Concrete

Abstract

Concrete is known to be is the most used construction material throughout the world to meet the needs of major infrastructure projects. Its superior structural strength and stability are mainly due to the presence of binding material cement. The production of cement accounts for large amounts of carbon-di-oxide throughout the world. This percentage is estimated to rise further increasing the CO2 levels in the coming future. It may not be avoided entirely, but it can be partially reduced by using supplementary cementitious materials. Fly ash is one such material that can be partially replaced with cement, with altering the strength of conventional concrete. Fly ash ranging from 0% to 50% was replaced with cement and the concrete was evaluated for compressive strength. Curing is also an essential factor in order to achieve the desired strength to the concrete. The heat produced during the hydration process needs to be brought down by curing, to maintain the favourable conditions for the surface of concrete. Various curing methods have been adopted, such as complete water immersion curing, 3-day water immersion curing, wet burlap curing, compound curing, and open-air curing. These specimens were tested for compression at 3 days, 7days and 28 days. It is concluded from the experimental results that at all ages, 20% fly ash replacement resulted in better strength. Complete water immersion curing proved to give better strength results, followed by wet burlap curing, 3-day immersion curing, compound curing, and open-air curing.