Highway maintenance mileage reached 5.25 million kilometers in China by 2021.Ultra-thin overlay is one of the most commonly used maintenance technologies,which can significantly enhance the economic and environmental ...Highway maintenance mileage reached 5.25 million kilometers in China by 2021.Ultra-thin overlay is one of the most commonly used maintenance technologies,which can significantly enhance the economic and environmental benefits of pavements.To promote the low-carbon development of ultrathin overlays,this paper mainly studied the mechanism and influencing factors of several ultra-thin overlay functions.Firstly,the skid resistance,noise reduction,rutting resistance,and crack resistance of ultrathin overlays were evaluated.The results indicated that the high-quality aggregates improved the skid and rutting resistance of ultra-thin overlay by 5%-20%.The optimized gradations and modified binders reduced noise of ultra-thin overlay by 0.4-6.0 dB.The high viscosity modified binders improved the rutting resistance of ultra-thin overlay by about 10%-130%.Basalt fiber improved the cracking resistance of ultra-thin overlay by more than 20%.Due to the thinner thickness and better road performance,the performance-based engineering cost of ultra-thin overlay was reduced by about 30%-40%compared with conventional overlays.Secondly,several environmentally friendly functions of ultra-thin overlay were investigated,including snow melting and deicing,exhaust gas purification and pavement cooling.The lower thickness of ultra-thin overlay was conducive to the diffusion of chloride-based materials to the pavement surface.Therefore,the snow melting effect of self-ice-melting was better.In addition,the ultra-thin overlay mixture containing photocatalytic materials could decompose 20%-50%of the exhaust gas.The colored ultra-thin overlay was able to reduce the temperature of the pavement by up to 8.1℃.The temperature difference between the upper and lower surfaces of the ultra-thin overlay containing thermal resistance materials could reach up to 12.8℃.In addition,numerous typical global engineering applications of functional ultra-thin overlay were summarized.This review can help better understand the functionality of ultra-thin overlays and promote the realization of future multi-functional and low-carbon road maintenance.展开更多
基金the National Key Research and Development Program of China(2022YFE0137300)the National Natural Science Foundation of China(52078018)the German Research Foundation(SFB/TRR 339 and 453596084).
文摘Highway maintenance mileage reached 5.25 million kilometers in China by 2021.Ultra-thin overlay is one of the most commonly used maintenance technologies,which can significantly enhance the economic and environmental benefits of pavements.To promote the low-carbon development of ultrathin overlays,this paper mainly studied the mechanism and influencing factors of several ultra-thin overlay functions.Firstly,the skid resistance,noise reduction,rutting resistance,and crack resistance of ultrathin overlays were evaluated.The results indicated that the high-quality aggregates improved the skid and rutting resistance of ultra-thin overlay by 5%-20%.The optimized gradations and modified binders reduced noise of ultra-thin overlay by 0.4-6.0 dB.The high viscosity modified binders improved the rutting resistance of ultra-thin overlay by about 10%-130%.Basalt fiber improved the cracking resistance of ultra-thin overlay by more than 20%.Due to the thinner thickness and better road performance,the performance-based engineering cost of ultra-thin overlay was reduced by about 30%-40%compared with conventional overlays.Secondly,several environmentally friendly functions of ultra-thin overlay were investigated,including snow melting and deicing,exhaust gas purification and pavement cooling.The lower thickness of ultra-thin overlay was conducive to the diffusion of chloride-based materials to the pavement surface.Therefore,the snow melting effect of self-ice-melting was better.In addition,the ultra-thin overlay mixture containing photocatalytic materials could decompose 20%-50%of the exhaust gas.The colored ultra-thin overlay was able to reduce the temperature of the pavement by up to 8.1℃.The temperature difference between the upper and lower surfaces of the ultra-thin overlay containing thermal resistance materials could reach up to 12.8℃.In addition,numerous typical global engineering applications of functional ultra-thin overlay were summarized.This review can help better understand the functionality of ultra-thin overlays and promote the realization of future multi-functional and low-carbon road maintenance.
