Balanced Design Of Porous Asphalt Mixture Road Surface Function

Porous asphalt mixture has many advantages such as drainage,anti-slip,noise reduction,flame retardant,safety,environmental protection,and so on.It is a multifunctional pavement material.With the development of the times,the excellent road surface function of porous asphalt mixture has received more and more attention.In this paper,porous asphalt mixture was studied as the research object,and its noise reduction,anti-slip properties,flame retardant properties and drainage characteristics were systematically studied,and its tail gas degradation performance was imparted by incorporating nano titanium dioxide into the mixture.With the help of industrial CT and image processing technology,the mesostructure of porous asphalt mixture with different void structure was described.The factors affecting the mesostructure of porous asphalt mixture,such as void ratio,maximum nominal particle size and gradation thickness,were explored.In comparison,the influence of three factors on the mesostructure of porous asphalt mixture is: void ratio > maximum nominal particle size > graded thickness.The standing wave tube method was used to evaluate the sound absorption performance of porous asphalt mixture with different thickness,void ratio,gradation thickness and maximum nominal particle size.It was recommended that the noise reduction pavement has a void ratio of about 24%,and according to different trafficcomposition,the corresponding thickness and maximum nominal particle size specifications are recommended.The anti-sliding performance of the porous asphalt mixture was explored by the temperature-controlled wheel type sander developed by the research group.It was found that the void ratio was 21%,and the road surface with the largest nominal particle size of 13.2 mm had the best anti-sliding performance.Using the self-made simulated precipitation device,the variation law of the drainage performance of the porous asphalt mixture was explored.It was found that the larger the void ratio,the better the drainage performance.The recommended porosity of the drainage pavement was 24%.By simulated combustion test,the flame retardant properties of porous asphalt mixtures with different void structures were studied The recommended void ratio of the flame retardant pavement was 21%,and the maximum nominal particle size was 16 mm.After the study of the function of the road surface,based on the research results of the meso-structure,the relationship between the meso-structure and the road surface function was explored,and the fractal dimension and the average equivalent diameter of the void are respectively taken as screening indicators for the noise reduction performance and drainage performance.The nanometer titanium dioxide was mixed into the porous asphalt mixture by means of equal volume replacement of the ore powder.The tail gas degradation performance of the porous asphalt mixture was explored by self-developed tail gas reaction and measuring device,and suitable nano titanium dioxide doping was recommended.The amount is 50%.Finally,the road performance of porous asphalt mixture was verified.Considering the balance of various road surface functions,it is recommended that the porosity of porous asphalt mixture be between 21-24%,combined with the study of mesostructure.The design process of the porous asphalt mixture composition was supplemented and improved.