Study On The Performance Of Steel Slag Asphalt Mixture

Steel slag is the product of steel refining process,which has a wide range of application prospects.In this project,steel slag is applied to the surface layer of road engineering,and the engineering characteristics of aggregate,asphalt absorption,asphalt mixture and engineering application of steel slag are studied respectively.First of all,through the study of the physical properties of steel slag,it is found that the steel slag has the characteristics of good adhesion with asphalt and delay in cooling.Through the study of the mechanical properties of the steel slag,it is found that the steel slag has excellent compressive crushing and wear resistance.Through the study of the expansion of the steel slag,it is found that the expansion of the steel slag with coarse grading composition is small.Secondly,through the steel slag adsorption test,it is found that with the increase of asphalt temperature,the adsorption capacity of the steel slag asphalt increases,and gradually becomes stable after increasing to a certain extent;the change of the steel slag temperature has little effect on the adsorption capacity of the steel slag asphalt,when the air bubble time in the oven is more than 70 minutes,the change of the absorption capacity of the steel slag aggregate asphalt tends to be gentle;when the asphalt impregnation method is used to measure the effective density of the steel slag aggregate,It is suggested that the heating temperature is 160℃,the heating temperature of the corresponding steel slag is180℃,the heating temperature of the modified asphalt is 180℃,the heating temperature of the corresponding steel slag is 200℃,and the bubble discharging time in the oven is 70 min.Thirdly,the expansion of steel slag asphalt mixture can be reduced by using low expansion limestone instead of high expansion fine steel slag.Through the test of high temperature stability,water stability,low temperature performance and fatigue performance of asphalt mixture,it is found that the dynamic stability and residual stability of steel slag asphalt mixture increase with the increase of immersion time,and under different immersion time,compared with limestone,the steel slag asphalt mixture with qualified expansion has better low temperature deformation ability and fatigue resistance.Through the atomic force scanning,it is found that the dynamic stability growth and excellent water stability of the steel slag asphalt mixture with qualified expansion are due to the formation of crystalline substances on the surface of the steel slag,which changes the surface roughness of the steel slag,increases the surface area of the steel slag,increases the adhesion between the asphalt and the steel slag,and increases the internal friction between the steel slag.In conclusion,the steel slag with qualified expansion can not only improve the overall performance of the road,but also reduce the pollution,which has the double functions of protecting the ecology and improving the social and economic benefits.