Disease Analysis Of The Asphalt Pavement And Research On The Disposal Plan Of Overlay

Based on the research about disease treatment methods of asphalt concrete pavement athome and aboard, this paper analyzed and summaried failure mechanism and disposalmethods of pits and cracks.. And combined technical renovation project of some expressways,the design、construction and actual performance of asphalt treated base is studied.In this paper,combine with the detection data of five expressways builded several yearsago in Jiangxi Province such as Zhang-Ji、Chang-Jiu、Jiu-Jing、Peng-Hu、Tai-Ganexpressway, results show that main diseases of asphalt concrete pavement in Jiangxi Provinceare pits and cracks and their derivatives diseases.The failure mechanism of pits and cracks isanalyzed. And disposal measures for different failure types are suggested. It will helpmaintenance and repair construction of expressway asphalt pavement. In this paper, based oncracks’ development and fracture mechanics, the influences of asphalt layer thickness andasphalt layer’ modulus is analyzed. Considering the economic efficiency, it is suggested thatthe thickness of asphalt grassroots is about16cm. When the asphalt stabilized macadammixture is used, some measures such as adding modifiers、changing the aggregate gradationmixture composition, should be taken to improve the resistant ability of mixture. It’s useful toprevent the reflection cracks of overlay.Researched the structure types of asphalt treated base,overlay the skeleton dense bitumen asphalt treated structure which internal friction angle andcohesion are also large on the original semi-rigid base or small deflection mild brokenpavement as composite base.This structure made full use of the original road base,alsoovercame shortcomings of semi-rigid pavement such as poor drainage performance,morereflection cracks caused more damage from bottom to up.In the construction of asphalt treatedbase, the production proportion(should be carefully adjusted.The grading curve of asphalttreated should be strictly controlled through the mesh design, grading curve extraction testand validated.The paving of asphalt treated shoule be thick layer paving,to ensure that theasphalt mixture skeleton structure is fully constituted, and thick asphalt layer is usefull to theheat insulation of the asphalt mixture.