Title: Efficiency of Finely Ground Blast Furnace Slags in High-Strength Mortars
Author(s): Ohama, J. MadejJ, and K. Demura
Publication: Symposium Paper
Appears on pages(s): 1031-1050
Keywords: binders (materials); blast furnace slag; compressive strength; curing; durability; porosity; silica fume; workability; Materials Research
The efficiency of finely ground blast furnace slags (BFS) was studied in relation to the fundamental physico-mechanical and structural properties of cement mortars. A positive effect of BFS fineness on the workability of fresh mortars was proved. Due to a small water content (20 percent by mass of the cementitious material) when combined with a high-range, water-reducing admixture (HRWRA), the compressive strengths of mortars ranging between 80 and 100 MPa are ascertained at normal curing conditions. Special curing conditions, such as autoclaving or hot water curing, produce specimens with compressive strengths in the range of 100 to 130 MPa, depending on the grading of BFS and the composition of the binder. With additional heat curing, the compressive strength of the mortars increase, in general, by about 10 to 50 percent over that of either autoclaved or hot water cured mortars. In this paper, some other properties of high-strength mortars incorporating finely ground BFS are discussed, including porosity and durability investigations. The efficiency of BFS addition is compared with other fine mineral powders, such as silica fume and fine silica powder, with special attention paid to binder compositions and curing conditions.