Effect of Initial Water Curing on Sorptivity Properties of Ordinary Portland and Pozzolanic Cement Concretes.

The water absorption properties of concretes measured by sorptivity test were investigated by using natural pozzolanic cements--CEM II/A and CEM II/B--and compared with those of ordinary portland cement (CEM I) concrete under varying water-curing periods. The mix design of concretes was made with an equal strength base at an age of 28 days under standard curing. The curing regimes include initial water curing periods of 3, 7, 14, and 28 days between continuous in-air and continuous in-water, and also 7-day delayed curing. Sorptivity and compressive strength tests were conducted at the age of 90 days. Although the difference between the sorptivities of air-cured concrete specimens for all cement types used is slight, under the water curing conditions, the differences between that of the CEM II/B concrete and those of the CEM I and CEM II/A concretes become significant. Also, considerable differences were obtained for the sorptivities of the CEM II/B concrete between the air-cured and continuous water-cured specimens when compared with those of the CEM I and CEM II/A concretes. [ABSTRACT FROM AUTHOR]