The Cryogenic Property Research On Asphalt Emulsion Cold Recycling Technology

Since the implementation of the western development strategy,the freeway in Guizhou province has developed rapidly.By the end of 2013,the total mileage of the highway exceeded 3000 km for the first time,and up to 3281 km.And freeway in Guizhou,has entered the coexistence era of new construction and stock maintenance,medium and large maintenance projects are increasing rapidly.It can be expected that asphalt pavement especially heavy load pavement depth involved in large and medium repair will be significantly larger,the old material disposal and utilization in large and medium repair program will be the problem which can not be avoided.Cold recycling technology has the advantages which can 100% recycle old material.And because of its minimal added aggregate,and similar to the regeneration process of aggregate coated hot asphalt,the emulsified asphalt cold recycling is the most non-controversial technology belongs to the technical method of flexible regeneration in all current cold recycling technology.It is foreseeable that in the future the total amount of recycled asphalt layer,the emulsified asphalt cold recycling will occupy a considerable share.Relying on "Mountain highway asphalt pavement cold recycling technology system" project,low temperature performance of emulsified asphalt cold recycled mixtures were studied in this paper.Primarily analyzes the aging and regeneration mechanism of asphalt,emulsifying mechanism and emulsion-breaking mechanism of emulsified asphalt and the strength formation mechanism of the emulsified asphalt cold recycled mixture,explains the states variation of RAP,and then analysis and evaluation of recycling old material moisture content,aggregate gradation,oil content and the variation of recycled asphalt,also studied design method of mixture ratio at home and abroad.Through Marshall test and compaction test to determine the optimal mix of emulsified asphalt content and the optimum water content.Posteriorly,analyzes the mechanism of low-temperature cracking of asphalt pavement and the effect factors of asphalt mixture cracking,contrastive analysises the evaluation method and evaluation index of low temperature cracking performance of asphalt mixture.And through indirect tensile test and flexural failure test respectively change the emulsified asphalt content,cement content and water content to comparative analysis low temperature anti cracking performance of asphalt mixture in differentcomponent content.At the same time,changes the test temperature of the mix proportion in this paper which is recommended.The test mixture specimens were tested by indirect tension test and bending test to study the failure strength of the mixture at different temperatures.Finally,takes example by the prediction model of low temperature cracking of asphalt pavement abroad-Hass,analysis their applicability and puts forward the low temperature cracking prediction model that is suitable for our country.