Effects of Kaolin on Engineering Properties of Portland Cement Concrete

The focus of this study was to determine the feasibility of using kaolin, a very small particle clay, as partial replacement of fine aggregates in Portland cement concrete (PCC). Kaolin clay is a locally available (Macon, GA, USA) and inexpensive clay mineral. The product, KaMin 90©, used has an average particle size of 1.5 microns and has a low embodied energy. The slump, air void content and compressive strength were examined on samples of PCC with different % of Kaolin. This research indicated the maximum kaolin substitution of fine aggregate for workability. An optimal dosage range for PCC cylinder compressive strength was also defined and found to be 33% greater than the control group. It was also noted that Kaolin engenders a soft and cohesive concrete mix that prevents segregation. A brief cost analyses was performed and determined the economic feasibility of Kaolin PCC.