Drying Shrinkage and Creep of Concrete Containing Granulated Blast Furnace Slag

Abstract

This paper will discuss how blast furnace slag concrete was made with different w/c, slag fineness, and amounts of slag, and cured for different periods. Drying shrinkage in air at 50 percent relative humidity (RH) and 20°C and creep in water at 20°C and in air at 50 percent RH were measured for 300 days. Drying shrinkage of concrete with granulated blast furnace slag was larger at early drying time and was lower for longer drying times with respect to the reference concrete. Using slag of specific surface area of about 8000 cm²/g, drying shrinkage of slag mortar was larger at 3 days curing but was lower after curing for 28 days. Creep of slag concrete was similar to that on nonslag concrete at the same compressive strength for concrete cured for 28 days, but for that cured for 7 days, creep of slag concrete was lower than that of the nonslag concrete. In the slag concrete cured by standard curing, the pore volume of cement paste is smaller and the proportion of fine pores is larger than that of nonslag concrete.