Study On Road Performance Of Steel Slag ARAC-13 Asphalt Mixture And Its Engineering Application

Steel slag as a by-product of the steel industry,large production,while having high strength and good wear resistance,good adhesion with asphalt,the use of steel slag to replace part of the traditional high-quality aggregate paving asphalt pavement,can reduce the consumption of high-quality aggregates,saving engineering costs.Rubber asphalt(AR)has good viscoelasticity,high and low temperature performance,good anti-cracking properties,and steel slag composite preparation of steel slag ARAC-13 asphalt mixture,not only to improve the road performance of the mixture,but also to inhibit part of the volume expansion of steel slag caused by the mixture cracking.In this paper,the chemical composition.volumetric stability and physical and mechanical properties of steel slag were analysed using hot bored steel slag from a converter in Fangchenggang,Guangxi.The study showed that the ageing time had a large influence on the chemical composition and volumetric stability of steel slag,and after 12 months of ageing,the alkalinity of steel slag decreased by 33%,the content of f-CaO and f-MgO decreased by 65.0%and 28.6%respectively,and the water absorption rate decreased by 61.4%;the physical index of steel slag was different from that of traditional stone,mainly in terms of high density,high porosity and water absorption rate.Steel slag has good mechanical properties,with high strength and wear resistance,mainly in the form of small crushing value,small abrasion value and large polish value.The volumetric stability and physical and mechanical properties of the steel slag coarse aggregates aged for more than 6 months meet the requirements for the preparation of asphalt mixes.The ARAC-13 asphalt mixes with different steel slag blending rates were prepared by replacing the same size of pyrochlore with steel slag in five groups of 0,25%,50%,75%and 100%,respectively,using the equal volume replacement method to study the effect of steel slag blending rate on the volumetric characteristics parameters and road properties of ARAC-13 asphalt mixes.The results of the study showed that the inclusion of steel slag increased the amount of asphalt in the ARAC-13 asphalt mixture,and the oil to stone ratio of the mixture increased by 0.1%～0.6%;the risk of volume expansion of the ARAC-13 asphalt mixture increased,and the volume expansion rate increased by 0.12%:some road properties were improved with the inclusion of steel slag.Stability increased by 23.2%,residual stability increased by 5.3%,freeze-thaw splitting strength ratio increased by 4.8%.pendulum value increased by 17.6%.structural depth increased by 8.6%and maximum bending and tensile strain increased by 13.4%at-10℃.Relying on the Guangxi coastal highway project.a test section of steel slag ARAC-13 asphalt mixture surface layer was paved to test its field road performance,and economic benefit analysis was conducted.The research results show that the steel slag ARAC-13 asphalt mixture has good field application.compaction.flatness,water density.etc.can meet the road project acceptance requirements:the use of steel slag to replace pyrochlore ARAC-13 asphalt mixture paving road surface layer has high economic benefits.The research results can provide scientific basis and engineering reference for the application of steel slag in asphalt mixes.