In this study, the particle size distributions of a cement powder system were adjusted using granulated blast furnace slag powder, Blaine 2250 cm2/g and 8300 cm2/g, with which it was easy to adjust the particle size distribution to examine how the particle size distribution of the binder effect the rheological properties of the cement paste. In addition, the relationship between the n-value of the Rosin-Rammler function and plastic viscosity is discussed. All of the measured flow curves represent thixotropic behavior. Also the hysteresis area was smaller with more added coarse particles such as OBB-4 and OBB-2. When the combination was based on a combination of 20-25 vol% fine particles, 30-40 vol% OPC and 40-45 vol% coarse particles in the total volume, a high fluidity and low yield strength was achieved. The plastic viscosity rises, as the n-value decreases and most of the samples indicated that the n-value was correlated with the plastic viscosity. However, in case of a sample which over 30 vol% of fine particles, the plastic viscosity decreased although the n-value decreased.

Keywords: Fluidity, Rheology, Cement, Blast furnace slag, Particle size distribution.