Research On Function Of Tack Coat Material And Prevention Of Reflective Cracking On Porous Asphalt Pavement

With the rapid development of freeway in our country,the early damage of asphalt pavement is very common,one of which is water-damage that is main reason causing early damage. So a new pavement construction is put forward against normal asphalt concrete pavement,whose construction has following character: the surface layer of asphalt pavement uses big peecenbagee of void asphalt concrete(the peecenbagee of void ranges from 15%~25%), the thickness is about 4~5 centimeter,the middle layer uses compact gradation asphalt concrete, upon which tack coat is laid out for better combination between layers and better prevention from leaking downward of rain. Because this kind of pavement construction can drain the rain that permeates the surface layer seasonably and rapidly,it is called porous asphalt pavement. however our country is on the beginning step for its research,facing many difficulty. Why the dissertation carries out the research for the tack coat is that few datum and information are available for us and pertinent technology guideline and standard have only attributable analysis but lack of quantitative analysis, and systematic experiments have not been seen yet. A series of experiments are underway , including material capacity guideline experiments , putting emphasis on shear strength and pull strength and the porous experiments, due to the particular location and construction requirement. By comparison of experiments, ideal tack coat material can be chosen, and some certain guideline will be modified, which is for further enforcement and spread. In another way,further researches have been carried about reflective cracking influence on pavement and by these factors of influence, we can demand material and guide the following practice.