Effect of Steam Curing on the Compressive Strength of Concrete with Blast Furnace Slag

This study aims to experimentally research the effect of steam curing on the compressive strength of concrete. The test variables included the compressive strength of concrete, two presteaming period (1.5 and 3 h), three curing temperatures (room temperature, 50 and 70 °C), and three blast furnace slag replacement ratios (0, 30, and 60%). Test results showed that with increase of the replacement ratio of blast furnace slag, it needed to increase the superplasticizer to achieve the required workability of concrete. At room temperature curing, the strength of control concrete was higher than that of concrete containing blast furnace slag before 28 days. With the increase of slag content, the growth rate of compressive strength tended to be slower. For the steam curing, the strength at 3 days was higher than that of the room temperature curing, and the strength at 28 days is lower than that of the room temperature curing. Longer presteaming period (3 h) and higher steam-curing temperature (70 °C) were helpful to the strength development of concrete with blast furnace slag at various ages. The concrete containing 30% blast furnace slag had the highest strength at all ages after 3 h presteaming period and 70 °C steam curing.