Research On Anti-skiding Durability Of Steel Slag Aggregate Based On Surface Micromorphology

With the rapid development of highways in our country,the traffic accident rate has also been increasing year by year,and the reduction of pavement slip resistance is one of the main reasons.The anti-skid performance of the road surface is mainly affected by the macro-texture and micro-texture of the road surface,and the micro-texture is the main influencing factor;the rougher the surface texture of the aggregate,the greater the contribution to the anti-skid performance of the pavement,and steel slag is a kind of Steelmaking waste has high hardness and rough surface.In an environment where the use of stone resources is increasingly tight,the application of steel slag to road paving can not only meet the requirements of road use,but also achieve the dual benefits of economy and environmental protection.The purpose of this paper is to explore the evaluation indexes and change rules of the surface micro-morphology of steel slag aggregates.Two types of steel slags(Jiugang,Yugang)and three types of stones(cobblestone,granite,limestone)are selected as the research objects;firstly,the aggregate image is adopted.The test system and pendulum instrument test the angularity and pendulum value of the undisturbed steel slag aggregate,and then use the laser confocal microscope to observe the surface micro-topography,and finally use the polarized light microscope and X-ray diffraction to explore the minerals of the steel slag aggregate ingredient.The results show that the surface micro morphology of steel slag aggregates can be evaluated by six indicators including the arithmetic average height,maximum height,surface skewness,and surface sharpness in the height parameters,and the peak density and average curvature of the peaks in the morphological parameters;The mineral structure of cobblestone is dense and the mineral particle size is small.The mineral structure of limestone,granite and steel slag is "matrix + phenocryst",and the content of five kinds of aggregate minerals are different.This is the main reason for the change of the surface micromorphology of steel slag aggregate..Different abrasion revolutions(0 revolutions,500 revolutions,1000 revolutions,1500 revolutions and 2000 revolutions)and different polishing times(0h,1h,2h,3h and 4h)were performed on five aggregates by the Los Angeles abrasion meter and polishing machine.)Processing,the angularity,texture and pendulum value measured by the image testing system and pendulum instrument are used to evaluate the anti-skid durability of the steel slag aggregate,and the surface of the steel slag aggregate is evaluated by the surface topography parameters measured by the laser confocal microscope.The law of microscopic morphology changes.The results show that the anti-skid durability of steel slag is better than that of stone,and the angularity of steel slag before and after abrasion is greater than that of stone;the surface texture of steel slag is similar to that of limestone and larger than that of granite and pebbles;the swing value of steel slag before and after polishing is greater than that of stone;the maximum height and surface deviation The correlation between surface sharpness and angularity and pendulum value is poor.The arithmetic average height,crest density,and average curvature of the crest have a good correlation with the angularity and pendulum value,which can be used as the evaluation index of aggregate micro-texture.Finally,a prediction model of steel slag aggregate sliding resistance based on the surface micro-morphology was established.Through the significance of the prediction model,it was found that the peak density has the most significant impact on the angularity of the steel slag,and the arithmetic average height has the most significant impact on the slag pendulum value;Density and the average curvature of the wave crest have the same significant influence on the angularity of the stone,and the density of the wave crest has the most significant effect on the rock pendulum value.