The Research Based On Aggregate And Gradation Of The Asphalt Pavement’s Forecast For Anti-sliding Performance

Anti slide performance is one of the main characteristics of the road surface, the better performance is beneficial to driving safely. Effect of surface characteristics of asphalt pavement is mainly affected by the characteristics of the aggregate and gradation. Under the conditions that aggregate characteristics and the composition are known, In order to be able to quantificationally evaluate and predict the skid resistance performance of the asphalt pavement anti slide surface, This paper will be based on "Research on The Effect’s Evaluation System of the Limestone’s Apply in The Asphalt Pavement’s Anti Slide Surface of Expressway in Henan Province", and based on the aggregate gradation, through theoretical analysis and laboratory test, on the basis of the research on the quantitative evaluation of anti slide performance of new asphalt anti slide surface and the attenuation test of skid resistance, put forward the prediction model of the anti slide performance of the asphalt anti slide surface, in order to provide reference for preventive maintenance for the construction control and preventive maintenance of anti skidding surface’s skid resistance.This paper introduces the function of road surface exposed aggregate size, which was based on the fractal theory, in order to quantificationally evaluate the skid resistance of new asphalt anti slide surface. Choosen limestone, Xuan Wuyan, granite, which are from different origin, and tested their crushing value, polished stone value, abrasion value, evaluated on effect of aggregate material origin to skid resistance, and the reason was analyzed. Respectively from the angle of coarse aggregate and gradation type, the anti slide performance of asphalt mixture under the condition of a certain material was tested. Through the accelerated loading test, researched on the attenuation low of skid resistance of anti sliding surface under the condition of different coarse aggregate type and different gradation, to get the influence from coarse aggregate type and gradation. And used the accelerated loading facility MMLS3, which could be idealized simulation the real contact state between tire and road surface, to simulated the decay process of skid resistance of anti sliding surface. And put forward the prediction model of anti slide performance, which was based on the coarse aggregate type and gradation.Through the research, the main conclusions are as follows:① Using the function of road surface exposed aggregate size, can calculate the fractal dimension of exposed size of aggregate under the condition of different gradation. Based on the fractal dimension, can quantificationally evaluate the skid resistance of new asphalt anti sliding surface:The fractal dimension is bigger, the skid resistance will be better; the fractal dimension is smaller, the skid resistance will be worse.② New anti skidding surface of the performance difference among different coarse aggregate in the same conditions of gradation is not big, but the new anti skidding surface of the performance difference among different gradation in the same conditions of coarse aggregate is significant. Effects of new anti slide surface’s skid resistance mainly comes from the influence of coarse aggregate gradation, types can be ignored.③ The attenuation law of asphalt anti skidding surface’s anti slide performance can be used for initial velocity attenuation, attenuation, attenuation, attenuation constant to evaluate. Difference of the attenuation speed, attenuation, attenuation value among different coarse aggregate in the same conditions of gradation is significant. When the coarse aggregate is different, the initial velocity attenuation and attenuation are significantly different, but the attenuation and attenuation value isn’t significantly different. And their attenuation curve is close to each other. Among them, the decay rate and aggregate exposure size fractal dimension is related, namely:the fractal dimension is greater, the greater the decay rate.④ The key stage of the asphalt pavement anti slide performance’s degradation can be summarized as four stable stage (early stationary phase, the first stable period, stable period, stable period of second end), the three decay phase(the first decline period, second period, third period) and one recovery period. The duration of each stage is related to the aggregate’s abrasion value and polished stone value.⑤ The anti slide performance prediction model:y=-Aln (x)+C, which is based on the simulation experiment, can help us to get the anti slide performance after a certain times of cumulative equivalent axle load, when the material properties and gradation was known. Among them:the decay rate of A=0.103a (wear value)-0.065b (Mo Guangzhi)+6.754 or A=0.1768s (the decay rate of crushing value)+1.9054; C is decay data, which is closely related to the asphalt mixture; x is the cumulative axle load (unit: million).