Research On The Mechanical Properties Of Cold Asphalt Mixture In Cold In-place Recycling Technology

At present, Our country's road construction is steping into the stage of conservation and maintenance. Wasting the original pavement materials in the road transformation and using new materials will not only cause environmental pollution, and waste resources. Therefore, according to the forms of current shortage of international resources,it is necessary to research on the recycling of waste asphalt mixture.Through researching on papers, laboratory testing, theoretical analysis and engineering experience is to summarize the experience of cold in-place recycling technology .In order to make the cold recycling technology more standardization and strict,we study deeply the key technologies of cold recycling,which focusing on the evaluation of old material, the research of recycling agent, gradation design , the method of mixture design.First of all, the paper analysis old asphalt pavement materials through the interior testing to evaluate the properties of cementitious material,which using the existing norms introduced penetration SHRP performance grading system and grading system for asphalt aging test.Secondly, it is necessary to research and analysis the current recycling agent (foam asphalt, emulsified asphalt),including the development of foamed asphalt.The paper uses orthogonal test to analysis the significantly factors of the bubble foaming properties of foamed asphalt and in the view of the present problems of recycling agent in the cold recycling technology to explore the research of recycling agent in the normal atmospheric temperature.Combination of our country noodle mixture layer and the majority of grass-roots tend to medium-grained mixture of the characteristics of style, from one of the key factors - gradation which effects of the cold mixture of renewable, based on the design of the structure of skeleton dense mixture of thought, through the N Act , K and I law designed gradation, and after Bailey method gradation testing, with a view to get the ringht gradation to avoid too broad gradation of material properties which lead to the uneven road surface, thus affecting the mixture of renewable cold pavement performance.Finally the paper researches on the cold mixture gradation which using foamed(emulsified) asphalt.Using the waste asphalt mixture as the research object, through the laboratory testing to study the mechanical properties of regenerant asphalt mixture and determining the best volume of recycling agent.Through the laboratory testing,we research on the properties about high temperature stability, water stability, fatigue characteristics of the regeneration mixture, with a view to promote renewable technologies .