LAUSR

Abstract In order to improve the cement use efficiency, a concept of reverse filling is proposed and applied to formulate a binary system of limestone powder-superfine Portland cement based on dense packing. The compressive packing model and the minimum water demand method were used to predict and measure the packing density of the binary blends containing 15%, 25%, 30%, 35%, 40% and 50% of superfine Portland cement. A maximum packing density can be achieved at a low content of superfine Portland cement (~25%), and the actual water to powder (cement + limestone filler) ratio can be reduced to 0.12 with the superfine Portland cement content between 25% and 30%. The compressive strength at 90 d reached 74.0 MPa and 94.0 MPa for the blends containing 25% and 30% of superfine Portland cement respectively. A very high cement hydration degree of ~93% was attained for the blend containing 25% of cement.