Study On The Influence Of Lithium Silicate Soaked Limestone On The Anti-sliding Performance Of Asphalt Pavement

Anti-sliding performance of road is one of the important factors affecting driving safety.Studies have shown that the wear resistance of aggregates has a great impact on the anti-sliding durability of asphalt pavement.Because the basalt with better wear resistance is mined too quickly,the distribution is less;if the limestone with abundant reserves and widely distributed is used on the surface of the asphalt pavement,the cost can be reduced.Lithium silicate has good wear resistance,water resistance,self-drying,etc.It is expected to improve its wear resistance for soaking aggregates,thereby improving the anti-sliding durability of asphalt pavement.To this end,this paper studies the limestone coarse aggregate soaked with lithium silicate to improve the anti-sliding durability and other road performance of the asphalt pavement surface layer.Due to the poor adhesion of the dry film formed on the aggregate surface of lithium silicate,the adhesion of the aggregate to the asphalt is also deteriorated.First,the lithium silicate is mixed with sodium silicate,potassium silicate,silicon-acrylic emulsion,pure acrylic emulsion,styrene-acrylic emulsion,silane coupling agent,pressure-sensitive adhesive emulsion,styrene-butadiene emulsion,VAE emulsion,and the mass ratio is 9:1,8:2,7:3,6:4,5:5.The aggregates soaked in the mixed solution were firstly selected by water immersion test and photoelectric colorimetric test.Through the Los Angeles abrasion test and the polishing value test,it was found that a mixture of lithium silicate and styrene-acrylic emulsion with a mass ratio of 8:2 and a mixture of lithium silicate and silicone-acrylic emulsion in a mass ratio of 6:4 The adhesion and wear resistance of the material are good,the adhesion is up to 5,and the wear loss is also reduced by about 25%.In order to analyze the mechanism of the two kinds of lithium silicate mixed solution to improve the wear resistance of limestone,infrared spectroscopy,scanning electron microscopy and aggregate image measurement were carried out.It can be seen from the infrared spectrum that the two mixed solutions are chemically bonded to the limestone.It was found by scanning electron microscopy that the two lithium silicate mixed solutions did not change the roughness of the aggregate.Through the aggregate image measurement test combined with the Los Angeles abrasion test,it can be seen that the styrene-acrylic mixture solution does not change the angular value of the aggregate,slightly improving the surface texture of the aggregate;the silicone-acrylic mixed solution does not affect the surface texture of the aggregate,but reduces the aggregate Angularity.Both mixed solutions improve the ability of the aggregate to maintain the angularity and surface texture;the angular-raising effect is the same,and the silicone-acrylic mixed solution has a stronger ability to maintain the aggregate surface texture.The effect of the coarse aggregate of silicate soaking solution on the anti-sliding performance of asphalt pavement was studied by using the loop-type accelerated wear meter combined with sanding method and pendulum instrument and untreated limestone as the comparison group.It is found that the initial structural depth of the styrene-acrylic mixed solution treated specimen is almost the same as that of the untreated test piece,but the initial structural depth of the silicon-acrylic mixed solution treated test piece is slightly smaller.The initial value of the two kinds of lithium silicate mixed solution treated specimens is the same as that of the untreated specimens,which indicates that the coarse aggregate of the two lithium silicate mixed solution does not improve the initial anti-sliding performance of the asphalt pavement.However,both the construction depth and the pendulum attenuation rate of the two treatment specimens are reduced,thereby improving the anti-sliding durability of the asphalt pavement.At the same time,the styrene-acrylic mixture solution has a better effect on the macrostructure of the asphalt mixture,and the decay rate of the structural depth of the test piece is reduced by about 19.0%;the silicon-acrylic mixed solution improves the microstructure of the asphalt mixture better,and the test piece is made.The decay rate of the pendulum is reduced by approximately 19.5%.Finally,through the water immersion Marshall test,freeze-thaw split test,rutting test,semi-circular bending test and three-point bending fatigue test,it can be seen that the two lithium silicate mixed solutions have an adverse effect on the water stability of the asphalt mixture,and the water stability of asphalt mixture treated with styrene-acrylic mixture solution is deviated,which reduces the water stability by about 10%.The two lithium silicate mixed solutions have no effect on the high temperature,low temperature and fatigue properties of the asphalt mixture.The aggregate and asphalt mixture performance test was carried out on the aggregate soaked in the lithium silicate mixed solution,and the mixed solution of lithium silicate and styrene-acrylic emulsion with a mass ratio of 8:2 was obtained,and the lithium silicate with a mass ratio of 6:4 was obtained.The aggregate soaked with the silicone-acrylic emulsion mixed solution can improve the anti-sliding durability of the asphalt pavement,and other road performances meet the requirements.The research results are expected to promote the use of limestone in the surface layer of asphalt pavement and reduce the construction cost,which has certain social significance and practical value.