Research And Engineering Application Of Hot In-place Recycling Technology For Asphalt Pavement

With the improvement of our comprehensive national strength and the improvement of infrastructure,the construction of highways has entered the stage of construction and maintenance.Asphalt pavement is the main road form of highway and urban road in our country.Early asphalt pavement were subjected to long-term vehicle loads and natural factors,there is a serious aging phenomenon in the pavement material.The traditional curing technology can not satisfy the concept of green development which put forward for the development of highway maintenance management in 13 th Five-Year.In response to the new concept,we must realize the recycling of limited resources.The Hot In-place Recycling Technology of asphalt pavement has been widely concerned.Its good social and economic benefits conform to the new concept.Therefore,the research of asphalt pavement regeneration technology is practical significance.On the premise of mastering the mechanism of aging and regeneration of asphalt.Using centrifugal separation to recover asphalt from old surface pavements and test the performance of recovered asphalt.Based on response surface center composite design test method,Introducing the Dynamic Shear Rheology(DSR)Test and Bending Beem Rheometer(BBR)Test in the US SHRP Index for experimental design of asphalt regeneration.Using rutting factor,creep stiffness modulus and creep rate as index to evaluate and analysis recycled asphalt which obtained from two different regenerants under different conditions.Optimize the optimum dosage of two different regenerants and their optimal regeneration conditions.In this paper,three kinds of recycled asphalt mixtures with different RAP content were designed.The mechanical properties and road performance of recycled asphalt mixture with different RAP content were tested and analyzed.Tests proved that recycled asphalt mixture has good road performance.The high temperature stability of recycled asphalt mixture will increase with the increase of RAP content,low temperature performance and resistance to water damage will decrease with increasing RAP content.When RAP content is 70%,low temperature performance and water loss performance are all optimal.Water stability cannot meet the requirement when RAP content is 80%,The design of recycled asphalt mixture should first consider its low temperature performance and water stability performance.Using ABAQUS to establish the finite element model to analyze the force and deformation of different contact states between layers and different thickness of regenerative layer.The results show that the thickness of the regeneration layer has a greatinfluence on the stress at the bottom of the upper layer.Vertical deformation and maximum shear stress under different contact conditions show different development laws.Whether continuous or discontinuous.The maximum vertical deformation of the pavement base layer occupies a larger part of the total vertical deformationFinally,based on the support of the project,this article studies the construction process of Hot In-place Recycling Technology.Testing the trial pavement section.The results show that the properties of the asphalt pavement after regeneration meet the requirements of China’s current regulations.Asphalt Hot In-place Recycling Technology can be used as an important maintenance technology to enter China’s road maintenance business.