The Application Of Asphalt Pavement Cold In-place Recycling Technology In Jilin Province Highway Reconstruction Project

Now,the highway construction is the rapid development in China.The freeway mileage is the second in the world(U.S.A is the first).This achievement is Chinese pride, and it is highly praised by the world peoples. But,the highway of forepart has come into the time of maintain. There is a significant amount of asphalt pavement to be reconstructed every year. If the current pavement maintenance technology is employed,much asphalt material will be abandoned,whose amount will increase with the augment of maintained asphalt pavement. Landfills have to be built to place the abandoned materials, polluting the environment and wasting the resource, especially in China, which lack high quality asphalt.The highway construction is a project that needs great money and lasts a long period. It hold the balance of civil economy and modem national defense. it ask for theory research and carry out manipulation of new material from the view of scientific and being practical and realistic to make use of limited financing to promoted highway construction.This paper contrapose hereinbefore circs, systematically expound the theory, experiment and practice of the use of Jilin province reclaimed asphalt pavement.Pavement cold-in place recycling is a new technique of form pavement structure. It include three steps: the fist step is the processing of old asphalt pavement material including asphal pavement and parts of road base material, then add some new bone-material or thin materialt these material according to the characteristic of cold recycling structure, at the same time add some water and in addition matter according the quantity of material. at last deal with these material in environment condition to form an new structure.The old asphalt mixture being dealt with cement is a cold in-place recycling method. The mechanism is that the crushed asphalt mixture and lime soil are reused and is stabilized by cement additive. So the material can be applied in base and subbase course such as cement stabilized aggregate.Firstly, based on the characteristic of cold recycling technology, its advantage is analyzed in this paper.the author analyzes the properties of asphalt binder by extraction and recovery experiment, mixture effects study, and chemical component analysis. Penetration, ductility and aromatic substance decrease, while softening point and viscosity increase. The author improves traditional extraction and recovery procedure, and advances a new method to extraction asphalt, which overcoming some limitations of old one.Secondly,the author analyzes the mechanism of asphalt aging and the practicable asphalt reclamation,adds rejuvenating agent to aged asphalt, then studies RAP properties.The author also mixes RAP and original asphalt and studies the mixture properties,mix design.The fact is that rejuvenating agent can improve the properties of aged asphalt.The mixture of RAP and original asphalt satisfies the requirement.Thirdly,the author designs constructing technics of the cement as cold in-place recycling additive and quality control of the cement as cold in-place recycling additive. Cold in-place recycling technology of Asphalt Pavement can debase construction cost and protect ecology environment too. it is great meaning for Chinese highway construction.The research indicates that cold in-place recycling of the old asphalt mixture is a favorable method for highway maintenance and reconstruction and especially should be applied in the region where is scarce of aggregate.At lasts the economy character of application of old asphalt concrete pavement in-place cold recycling technology given out in detail. it can be used to be the scientific base of pavement structure design, construct, and supervise of apply cold recycling technology. To sum up, the theory research and application of cold recycling technology will save lots of money, alleviate environment pollution and bring up unlimited economy and society benefit.