| With the vigorous development of Chinese economy,the road transportation industry continues to develop.The phenomenon of heavy and overloaded vehicles is becoming more and more obvious.The high-grade asphalt pavement to be maintained often has the phenomenon that the pavement structure is intact,but the performance is greatly reduced.The use of additional wear layer can effectively restore pavement performance.At present,most researches on ultra-thin wear layers focus on wear layer material design and road performance,and lack of research on surface functions.Therefore,this paper takes the wear layer material and gradation as the research object,and the road performance and the surface anti-slip and noise characteristics as the research goals to study the ultra-thin wear layer,has very important practical significance.SBS and waste rubber powder are selected as modifiers,and asphalt is modified by different preparation processes.Based on the high temperature failure temperature of PG76,the amount of different modifiers was determined.Through the Marshall test,the optimal asphalt dosage of different types of mixtures was obtained,and the road performance test was carried out.It is found that the asphalt mixtures tested in this article have good road performance.The numerical simulation of different modulus,load,wear layer thickness and horizontal force coefficient was conducted by ANSYS finite element analysis software,and it was found that the maximum shear stress position between the layers was 0.6r.It is recommended to use a high modulus wear layer to reduce the layer Shear stress.When the load increases from 0.7MPa to 1.1MPa,the shear stress increases by 1.6 times.It can be seen that the overloading of roads puts forward higher requirements on the bonding performance of the adhesive layer material.The effects of asphalt and gradation on the anti-sliding performance of asphalt and gradation mixture were evaluated by sand spreading method,pendulum friction test method and texture scanning AMES method.Grey correlation analysis was used to evaluate the influence of different factors on anti-skid performance.An accelerated abrasion tester was used to abrade the rut board to evaluate the decay law of the anti-slip properties of the abrasion layer.It is found that the effect of the gradation on the anti-sliding performance ofthe wear layer is greater than that of asphalt;the anti-slip decay law of the different asphalt and gradation wear layer is the same,and the wear process of the rut board is divided into the compaction stage-polishing stage-stabilization stage.Through the DSR temperature scan test and indoor tire drop method noise test,the impact of asphalt damping characteristics and gradation on the wear layer noise was analyzed.With the aid of the accelerated abrasion meter,the decay laws of the noise characteristics of different types of wear layers were analyzed and evaluated,and the influence of different factors on the sound pressure value of the wear layer was analyzed and evaluated using gray correlation analysis.It was found that the SBS asphalt binder has a large loss factor,has good damping characteristics,and the SMA wear layer has a low noise level;the effect of the cascade noise level is greater than that of the asphalt binder.Based on the surface functional characteristics,using the dispersion index,the UTFC(SBS)modified asphalt mixture wear layer is proposed as the optimal combination. |
