Study On The Application Of Metallurgical Steel Slags In The Preparation Of High Quality Pavement Brick

In the production process of iron and steel enterprises,a large number of metallurgical steel slag and other "by-products" will be produced.Due to its complex composition and large changes in composition,it is difficult to recycle on a large scale and efficiently.Not only caused serious waste of resources,but also brought environmental pollution and other problems.Therefore,on the basis of analyzing the properties of metallurgical steel slag with different treatment processes,this paper makes a systematic study on the use of metallurgical steel slag micro-powder and metallurgical steel slag tail slag as concrete mineral admixture and aggregate.And it is used in the production of concrete products.It is helpful to understand the characteristics of steel slag and provide experimental basis for its engineering application.The main contents and results are as follows:Firstly,the chemical composition and mineral composition of metallurgical steel slag obtained by "shallow plate method","water quenching method","stuffing method","drum method" and "grid method" are compared and analyzed,and their properties are studied.The results show that compared with shallow plate method,stuffing method and water quenching method,the metallurgical steel slag treated by drum method has lower content of calcium oxide and less influence on the stability of cementing material,and the high content of calcium ferrate is beneficial to improve the abrasion resistance of the products.The addition of gypsum can stimulate the activity of metallurgical steel slag powder and reduce the harm of bad volume stability caused by large amount of metallurgical steel slag powder;Secondly,the influence of metallurgical steel slag powder as admixture on flexural strength,compressive strength,brittleness,dry shrinkage resistance and abrasion resistance of concrete was studied.The results show that the flexural strength of concrete can be improved and the brittleness of concrete can be reduced by replacing cement with steel slag,but the flexural and compressive strength of concrete can be decreased when the substitution amount is too high.When the cement content of steel slag is more than 50%,the dry shrinkage of concrete can be increased,and the abrasion resistance of concrete can be improved when the substitution amount is more than 30%.Finally,the effect of replacing part of concrete coarse aggregate with metallurgical steel slag tailings on strength,brittleness and abrasion resistance of concrete is studied.The abrasion resistance of concrete is improved more obviously by replacing part of coarse aggregate with steel slag tailings of roller metallurgy,and when steel slag tailings are added to replace 20~60 stone,the flexural strength of concrete can be improved in 28 days and the brittleness of concrete can be reduced.The abrasion resistance of concrete can be improved significantly by adding steel slag in roller process.The metallurgical steel slag concrete pavement brick made of metallurgical steel slag powder and metallurgical steel slag tailings as concrete admixture and aggregate has been applied in some projects and achieved good economic and social benefits.