Abstract: In order to explore the feasibility of steel slag addition in cement to realize high efficient utilization of steel slag,the effects of different particle size and different mixing amount of steel slag were studied on the cementitious properties of cement by using steel slag from Panzhihua Steel and cement clinker from Esheng Cement Group as raw materials.The results showed that,with the same mixing amount of steel slag,both the water requirement of normal consistency and the initial and the final setting time of cement were increased with the decrease of the particle size of steel slag.In addition,the activity index and the strength of cement mortar were also increased.With the same particle size of steel slag fine powder,the strength of cement mortar was decreased with the increase of steel slag fine powder.When the mixing amount of steel slag fine powder was above 30% by weight，the strength of cement mortar was decreased significantly.When 30% of cement by weight was replaced by steel slag fine powder of D₅₀=3.17 μm or D₅₀=6.21 μm,the strength and soundness of the cement mortar with steel slag could reach the standard of P.S.A 32.5 cement.

Key words: Steel slag fine powder, Particle size, Mixing amount, Cementitious property