The Research On Skid Resistance Performance Of Limestone Used For Asphalt Pavement Surface Layer

The coarse aggregate used in the surface layer of highway asphalt pavement in our country is mainly basalt.With the development of highway,it can be predicted that in the future for a long period of time the highway construction for coarse aggregate demand is still quite huge.This will inevitably bring about a shortage of basalt,resulting in a series of problems,such as engineering cost,logistics cost and project schedule.Limestone reserves are abundant and widely distributed,if the limestone used to surface layer construction,it will help to relieve contradiction between supply and demand,and produce positive effect on the development of highway in our country.Therefore,the feasibility and skid resistance characteristics of limestone in the surface layer are studied in this paper combining with the highway engineering,it will provide a basis for the wide application of limestone.In this paper,the distribution of limestone indicators are concluded by means of investigation to provide statistical basis for the suitability of limestone for the surface layer.This paper studies the decay of skid resistance performance of limestone AC-13 and SMA-13 asphalt mixture by changing the composition of asphalt mixture,aggregate type,grain shape and other experimental conditions in laboratory with accelerated wet abrasion tester.This paper studies on skid resistance performance deterioration,the performance difference between limestone and basalt through field testing in highway.This paper also studies mixed coarse aggregate effects on skid resistance performance through aggregate replacement,and use the design parameters of mixture to evaluate the macro texture.Finally,it summarized and improved a design method for asphalt mixture based on the braking distance.The results show that the limestone basically meet the specification requirements of coarse aggregate technology,polished value deficiency is the main obstacle for the limestone of the surface layer.The skid resistance performance in the early decay rate is faster,the latter is relatively stable.The mixture,aggregate type and grain shape can greatly affect the skid resistance performance.The asphalt mixture with replacement of coarse aggregate can effectively improve the skid resistance performance.The initial texture depth can basically determined by gradation parameters,the prediction model has certain reliability.In summary,the limestone asphalt mixture will exhibit good skid resistance performance with the reasonable control and optimization measures.As a kind of potential aggregate,limestone can be used for highway surface.