Effect of Improper Curing on Concrete Performance

In a drive to reduce the carbon footprint of construction, the cement industry increasingly uses supplementary cementitious materials, such as pulverised fuel ash (PFA). However, such binder hydrates more slowly and may require longer curing times. This project has looked at the impact of improper curing as a function of concrete mix design; (CEM I 52.5N) vs. CEM I plus 30%PFA replacement, workability (10 to 30 and 60 to 180 mm slump) and target mean strength (20, 50 and 80MPa). Samples were cured in fog room at 200 C or under ambient conditions 200 C and 42% RH. The degree of saturation (DOS) of concrete affects the measured strength. Performing strength testing at constant degree of saturation is of interest to know the effect of improper curing. Therefore, in this study subsequent to curing, the specimens will be dried in oven at 400 C to constant weight, unconfined compressive strength will be determined at various degrees of saturation while changes in weight will be measured also. The result of compressive strength against time will be plotted and there the effects due to DOS will be obtained with the effect due to degree of hydration. The impact of each of the mix design variables mentioned above on improper curing and the DOS will be studied.