Study On Evolution Behavior Of Skid Resistance Of Asphalt Pavement Design Of Long-term Anti-skid Surface In Humid And Hot Areas

Skid resistance is the most important indicator reflecting road safety performance.Good anti-skid performance is the guarantee of safe and fast driving of vehicles.However,with the rapid increase in traffic volume and proportion of trucks,a series of issues are gradually exposed on the asphalt pavement of expressways in China,such as a rapid decline in anti-skid performance,which affects driving safety.One of the current research hotspots is how to design an anti-skid surface that meets the requirement of lifetime service: Possess long-term skid resistance performance and maintain a good level of anti-skid ability.This research takes the typical anti-skid surface of Guangdong expressway as the research object.A combination of road network investigation,theoretical analysis and accelerated pavement test were adopted.A systematic research was carried out from the aspects of asphalt pavement skid resistance performance test method,evolution law,key influencing factors,prediction model,etc.The relational model between the sideway force coefficient of the asphalt pavement and the road surface texture parameters was established based on feedforward network simulation;The evolution of the anti-skid performance of asphalt pavement in hot and humid areas was revealed based on the large samples of skid resistance performance data of asphalt pavement.A prediction model for the long-term skid resistance performance of asphalt pavement was constructed,and proposed evaluation index and standard of asphalt mixture anti-skid durability;Based on the aforementioned research content,a long-term skid resistance surface design method for asphalt pavement was formulated.The main work and highlight of innovation in this thesis are as follows:(1)In view of the problems existing in the sideway force coefficient test system(SCRIM),the method of using SCRIM to measure asphalt pavement sideway force coefficient was optimized based on the field experiment results.This thesis recommends the tire wear correction method of SCRIM,establishes the temperature correction model to accurately represent the sideway force coefficient of asphalt pavement,and recommends the temperature correction value of asphalt pavement sideway force coefficient at different surface temperatures,which improves the accuracy and reliability of the sideway force coefficient test of asphalt pavement in hot and humid areas.(2)A 3D laser texture detection system for asphalt pavement is developed.Through programming and software development,the measurement and characterization of 3D surface topography index of asphalt pavement are realized,and the texture index of asphalt pavement skid resistance performance was proposed;In order to solve the problem of low accuracy of multiple linear regression model,the relationship model between asphalt pavement sideway force coefficient and texture index was established by using feedforward neural network method.It provides a research basis for accurately characterizing the skid resistance performance of asphalt pavement by using texture index.(3)Based on the large sample data of skid resistance performance of asphalt pavement,this thesis analyzes the attenuation characteristics and evolution behavior of typical asphalt pavement skid resistance.Furthermore,the key factors(gradation,asphalt content,void content)that affect the mean texture depth(MTD)and initial value of sideway force coefficient(SFC)of asphalt pavement and the key factors affecting the SFC stability value of asphalt pavement(Cumulative number of axle loads of truck,gradation scale factor λ,gradation shape factor κ,and aggregate PSV)are put forward.In addition,the prediction model of skid resistance performance index MTD,initial value of SFC and stable value of SFC of asphalt pavement in hot and humid areas are established.It provides technical support for quantitative design of skid resistance asphalt pavement.(4)Based on the indoor accelerated pavement test,the skid resistance attenuation characteristics and the key factors affecting the long-term skid resistance performance of asphalt mixture are studied.Furthermore,the attenuation prediction model of skid resistance performance index BPN based on indoor accelerated pavement test was constructed,and the consistency is verified between the prediction results of this model and the prediction model of asphalt pavement skid resistance performance.Based on this,the index B and standard of skid resistance durability of asphalt mixture are proposed.(5)Finally,based on the prediction model of asphalt pavement skid resistance performance,the evaluation index of asphalt mixture skid resistance durability and the application situation of aggregate for asphalt pavement in Guangdong Province,the technical standard of skid resistance surface layer aggregate considering traffic parameters and asphalt mixture type is recommended.In addition,the design method of long-term skid resistance asphalt pavement based on mixture gradation is formulated.The results of this thesis can not only guide the accurate design and scientific maintenance of skid resistance asphalt pavement in hot and humid areas,improve the safety of asphalt pavement and reduce the occurrence of traffic accidents,but also provide reference for improving the design method of skid resistance asphalt pavement in China.