Improving Particle Size Distribution in Cement Paste by Blending with Superfine Cement
Keywords:Packing density, particle size distribution, paste, rheology, superfine cement
The rheological and mechanical performance of cement paste is closely related to its packing density, which may be optimized by improving the particle size distribution in the paste mix. In this study, the authors propose modifications to the existing mathematical equations of particle size distribution. The new equation of optimal particle size distribution so formulated is verified experimentally. A series of cement paste having different water/cementitious materials (W/CM) ratios were produced by blending ordinary Portland cement (OPC) with varying contents of superfine cement (SFC). The particle size distributions of the blended paste mixes were compared with the proposed equation. The packing density of paste mixes was measured using the wet packing test method, and the flowability, rheological properties, and compressive strength of the paste mixes were tested. It is found that the particle size distribution in cement paste can be improved by blending with SFC, which can lead to enhancement in packing density, flowability, rheology and strength. The authors opine that the proposed equation of particle size distribution may be applied for mix design optimization of cementitious paste, including cementitious grout and the paste phase in mortar and concrete.