Study On Anti-sliding Treatment Of Lithium Silicate On Limestone Asphalt Pavement

With the continuous increase of highway mileage and the improvement of economic level in China,higher quality has been required for road service and driving safety has attracted much attention.At present,the upper layer quality of asphalt pavement in China is gradually reduced and the price is rising.Limestone is a kind of optional road construction material with large reserves,wide distribution,excellent economy and good adhesion to asphalt.However,the lack of anti-wear performance of limestone severely restricts its large-scale application in high-grade road pavement.Aiming at the technical problem that the anti-sliding performance of limestone asphalt pavement is attenuated too fast,the development of a functional surface treatment material can quickly improve its anti-sliding performance and provide a basis for the promotion and application of limestone in the surface of high-grade asphalt pavement,which will have important realities and engineering application value.In this paper,the following experimental research is carried out with the research on the anti-sliding material of lithium silicate limestone asphalt pavement.Firstly,the pendulum BPN and the structural depth MTD were used as evaluation indexes,and the anti-sliding performance of the coarse aggregate type on the asphalt mixture was analyzed.The influence of the rough aggregate index which has the greatest influence on the anti-sliding performance of the pavement is the polishing value and the anti-slip treatment for the limestone asphalt pavement.Secondly,the lithium silicate was comprehensively modified by emulsion,curing agent and drier.Two emulsions and their addition ratio of lithium silicate were chosen by the film hardness test,the limestone adhesion grade test and the aggregate accelerated polishing test.The mass ratio of lithium silicate to silicone-acrylic emulsion was 8:2 and that of lithium silicate to styrene-acrylic emulsion was 6:4,respectively.Also combined with viscosity and drying time test,the types and dosage of curing and drying agent were determined.Thus lithium silicate composite solution for anti-slip surface could be prepared,and its uniformity was evaluated by particle size test.Thirdly,the limestone aggregates prepared by the prepared lithium silicate composite solution were analyzed by scanning electron microscopy,infrared spectroscopy and texture analysis.The results showed that the lithium silicate composite solution could not effectively improve the roughness of the polished limestone,lithium silicate.There is no chemical reaction in the preparation of the composite solution,but a chemical reaction occured between the lithium silicate composite solution and the limestone.Finally,the mixture ratio design of silicon carbide and lithium silicate composite solution was carried out.The optimum mixing ratio of sand and lithium silicate composite solution was determined by analyzing the structural depth of the anti-slide surface,the change rate of the pendulum value and the loss of the wear quality.And the order of spraying,followed by accelerated polishing test and SEM-based microstructure analysis,proved that the developed sand-containing lithium silicate could improve the wear resistance of limestone and its microtexture.Subsequent research on the road performance of the sand-containing lithium silicate asphalt mixture showed that the sand-containing lithium silicate could achieve good anti-sliding effect and withstand various natural environmental conditions.Also it could improve the oil resistance,flame retardant and impermeability of the asphalt mixture.According to the road performance test results,the amount of sand and the application range of sand-containing lithium silicate were recommended.Meanwhile,the construction technology of the sandresistant lithium silicate anti-sliding surface layer was discussed,its economic and social benefits were evaluated simultaneously.The development of the sand-containing lithium silicate composite surface layer can be applied to the anti-sliding maintenance of limestone asphalt pavement,which provides a new idea for the anti-sliding function recovery of limestone asphalt pavement and has important engineering significance.