Effect of Phosphate Cement and Aggregate on the Fluidity and Strength of Phosphate Concrete

To prepare the concrete of high strength and high fluidity, some important factors were investigated, namely species of phosphate, the ratio of phosphate and magnesia, the surface area of phosphate cement, fineness of sand, particle size distribution of coarse aggregate and the ratio of phosphate cement and aggregate. Results showed that the fluidity and strength of phosphate concrete prepared by KH2PO4 were lower than that prepared by NH4H2PO4 and decreased as the ratio of P/M reduced. The surface area of phosphate cement increased from 210m(2)/kg to 400m(2)/kg, the fluidity and strength firstly increased, and then decreased. The fluidity and strength of phosphate prepared by medium sands were lower than that prepared by fine sands or super-fine sands. Fast harden and early strength phosphate concrete of high fluidity can be prepared by three kinds of coarse aggregate, namely 5 similar to 10mm, 5 similar to 20mm and 5 similar to 25mm. Besides the ratio of cement and aggregate had a significant effect on the fluidity and strength, and the best ratio fell between 1:1 and 1:2.