Research Of Clogging Behavior Of Porous Asphalt Pavement

Permeable asphalt pavement is a kind of environmental protection product with penetrative pores made by a special mix proportion,and it retains enough strength,but also has acoustic,pervious,breathable,thermal permeability.Permeable asphalt pavement has been gradually used in municipal engineering and landscape engineering,it has been achieved good ecological benefits,social benefits and environmental benefits.Permeable asphalt pavement is widely used,which mainly depends on its good breathable and pervious performance,but when the permeable asphalt pavement in the event of congestion,the drainage ability will decline substantially.Under different mat on the road,the characteristics of the sediment have significant differences.Under the atmospheric precipitation,rainwater carrying with substantial sediments,such as silt,enters into the void of different structure of permeable asphalt pavement,then causes jams and weakens its drainage function.In order to reveal the influence factors of permeable asphalt pavement and the behavior pattern of congestion,this article prepared the pavement mixture of different proportion conforming to the specification requirements,then designed a kind of test device of permeable asphalt pavement block simulation,and made a series of indoor simulation test.Finally,by changing the permeable asphalt pavement void ratio,maximum nominal size and gradation type,rainfall intensity,clogs gradation types and so on,to analyze the impacts of plugging behaviors of permeable asphalt pavement.And making the permeability coefficient and the distribution of the simulated stemming quality as the main evaluation indexes drew the three modes,the discriminant criteria and the characteristics of various modes of the permeable asphalt pavement blockage behavior.In this paper,we get the following conclusion:(1)According to the characteristics of the permeable asphalt surface,in order to ensure the road surface in the process of rainfall runoff can be timely and effectively discharge,design pavement void rates were 18.1%,21.2%,23.9% respectively,and the grading is classified into partial coarse and fine,and the maximum nominal size is controlled.Through the fort,Kentucky flying test and fort shellen analysis leakage test to determine the best asphalt dosage range of 5.5% ~ 5.5%.(2)In the pavements of different function,the distribution difference of sediment particle size is big,but is basically symmetrical distribution,where its medium sand and silt quality is most,coarse sand and coarse sand and clay content is relatively small,more than 80% sediment particle size of the country’s road is below 500 μm.(3)The process of plugging behaviors could be roughly divided into four stages,rapid plugging stage,partial recovery stage,and gradual blockage stage and steady flow stage.Anti-clogging ability of partial type coarse gradation is smaller than type gradation.The bigger maximum nominal size of mixture is,the greater anti-clogging ability is,and the greater the rainfall intensity is,the easilier the permeable asphalt pavement is to congest.Full graded blockages have the biggest impact on congestion.(4)By the ratio of DP/d50,the patterns of permeable asphalt pavement clogging behavior can be divided into three models: clogging of pie on surface,internal space clogging and internal-surface clogging.