Durability of high volume fly ash concrete exposed to H2SO4 environment

This paper discusses on some experimental investigations on performance of concrete incorporated with fly ash as cement replacement material. The fly ash content was varied from 0.0% to 60.0% by weight of cement. Different concrete mixes were proportioned at constant binder content with different water-binder ratios. The influence of these parameters on the ability of concrete to withstand the impact of aggressive H2SO4 concentration in water solution. Three different concentrations of 1.0, 3.0 and 5.0% of H2SO4 in solution have been adopted to investigate the loss in strength and weight of concrete. Concrete immersed in concentrated H2SO4 solution showed significant deterioration and color change. The strength of concrete decreases with increase in H2SO4 concentration. As the concentration of H2SO4 increases the loss of weight of concrete increases. At low replacements of cement by fly ash, the losses in strength and weight have been observed to be significantly high. As the percentage of fly ash in cement increases, there has been significant improvement in the resistance of concrete against H2SO4 influence. The losses in strength and weight of concrete decrease high volume fly ash concrete mixes. With different combinations of cementitious material (cement plus fly ash = binder), water-binder ratio and concentration of H2SO4, the concretes produced using high volume fly ash improve their durability. High volume fly ash concrete seems to be an efficient material for developing high performing durable concretes.