Effect of Curing and Drying on Strength and Absorption of Concretes Containing Fly Ash and Silica Fume

Abstract

In this study, the effect of curing and drying on the strength and absorption of plain and pozzolanic cement concretes were evaluated. The specimens were cured for 1, 3, 7, 14, 28 and 60 days. At each testing period, specimens were oven dried at 70 degrees Centigrade for 2, 8, 12 and 24 hours. The effect of curing and drying on the absorption capacity of concrete specimens was evaluated by measuring 48-hour absorption and volume of permeable voids. The specimens were also tested for compressive strength and moisture content. The results show an increase in the compressive strength in plain and pozzolanic cement concretes with increased curing and drying time. The absorption of these concretes decreased with time of curing and increased with drying period. The absorption of both fly-ash and silica-fume cement concrete specimens decreased significantly after three to seven days of curing. While the absorption of plain concrete specimens were effected significantly by drying period, no significant change in the absorption of pozzolanic cement concretes due to increasing drying period was observed, especially after seven days of curing. The volume of permeable voids also decreased with curing. The highest reduction in the absorption and volume of voids was observed in the fly-ash cement concrete specimens.