Research On The Pervious Concrete Prepared By Steel Slags As Aggregate

The utilization of steel slag as a resource is a pressing problem in iron and steel industry at present due to poor grindability, low activity and poor stability because of the existence of f-CaO. Aiming at the existing problems of application of steel slag, the research of pervious concrete prepared by steel slag as aggregate and slag- fly ash as mineral admixtures instead of part of cement was carried on in this paper. Firstly; through the analysis of chemical composition, mechanical properties and stability of steel slag, the feasibility of the steel slag utilized in the pervious concrete was studied. Then the performance of steel slag pervious concrete was studied, including the influence of the aggregate-paste ratio, the water to cement ratio and the aggregate particle size on the compressive strength and the permeability coefficient of the slag pervious concrete. Finally, the effect of different content of composite powder on the properties of steel slag pervious concrete was studied by the properties of the slag pervious concrete mixed with composite powders which was composed of slag and fly ash.The results showed that the compressive strength of steel slag concrete decreased with the increase of the aggregate-paste ratio. With the increase of water to cement ratio, the tendency of the compressive strength of steel slag concrete increased firstly and then decreased. Through the orthogonal experiment, the best combination of the factors of the level of the aggregate particle size is 9.5-13.2mm, the water to cement ratio is 0.29 and the aggregate-paste ratio is 3.8. The compressive strength of steel slag with different content of composite powder increased firstly and then decreased with the increase of the content of composite powder. When the content of the composite powder is 30%, the compressive strength of the steel slag pervious concrete is the largest, and the permeability coefficient and the porosity meet the standard, and the flexural strength can also meet the requirements. The frost resistance and abrasion resistance of the steel slag pervious concrete mixed with composite powder are superior to that of the cement slag pervious concrete. The production cost of concrete was reduced and the strength of concrete was strengthed by using 30% composite powders substitute cement to make steel slag pervious concrete so that the economic and social benefits improved.