Analysis Of Influence Factors On Optical Reflection Characteristics Of Asphalt Pavement

The optical reflection coefficient of pavement material is one of the important parameters in road lighting design.At present,the road lighting design in China and abroad mostly uses the empirical value of the 1970s as the reflection coefficient of asphalt pavement.And there is no targeted research for different types of asphalt pavement.This leads to the deviation between the actual brightness of the road and the design brightness,affects the accuracy of road lighting design,and has a negative impact on road traffic safety and lighting energy consumption.In this paper,the influencing factors of pavement optical reflection characteristics are studied from the perspectives of surface morphology,macro and micro texture of asphalt pavement.Firstly,the surface texture characteristics and optical reflection characteristics of 12 asphalt pavements are measured,and 11 kinds of macroscopic and microscopic texture indexes which include mean profile depth(MPD),mean texture depth(MTD),macroscopic texture surface area(S1),microscopic texture surface area(S2),macroscopic texture distribution density(D1),microscopic texture distribution density(D2),contour arithmetic mean deviation(Ra),contour root mean square deviation(Rq),contour root mean square slope(Δq),skewness(Rsk),kurtosis(Rku)and pavement retro-reflection coefficient(RL)are collected.Then,the index correlation analysis and modeling are carried out,and the single factor and multi-factor regression models between macro and micro texture parameters and RL are established.Finally,four different types of(AC,SMA,PAC,OGFC)rutting specimens are made.The applicability of single-factor and multi-factor models are verified by measuring the texture and optical indexes of different rutting specimens.The results show that seven indicators(S1,D1,S2,D2 Δq,Rsk and Rku)are highly correlated with RL.And the established single-factor and multi-factor regression models have high prediction accuracy.The relevant research results can provide ideas for the optimization of reflection coefficient of asphalt pavement materials.It can further provide decision-making basis for accurate road lighting design.