Study On Cold Mix Cold Pave Waterborn Epoxy Emulsified Asphalt Mixture

Compared with hot asphalt mixture(HMA),cold asphalt mixture(CMA)has the advantages of simple construction,cost saving and less environmental pollution.However,the application of CMA is limited because of its long curing time,low early strength and poor water stability.In view of the above problems,waterborne epoxy resin used as emulsifying asphalt modifier to improve the strength and water damage resistance of CMA,and prepared waterborne epoxy emulsified asphalt cold mix for new pavement surface.The high temperature performance of waterborne epoxy emulsified asphalt,mix proportion design and road performance of waterborne epoxy emulsified asphalt mixture and paving test road were studied.The main conclusions were as follows:(1)Epoxy resin can improve the deformation resistance,elastic part and elastic recovery of emulsified asphalt at high temperature.The complex shear modulus of emulsified asphalt with different epoxy content is linearly correlated with Marshall stability and splitting strength of CMA at 58 and 64℃,and the correlation coefficient is above 0.97;(2)According to the characteristics of waterborne epoxy resin,the modified Marshall test was used to design the mix proportion of different cement dosage,mineral powder dosage and emulsion dosage,and the effects of compaction frequency,aggregate temperature and mixing method were analyzed.The best mix proportion of CMA was 9%emulsion,5% mineral powder and 2% cement;(3)The low temperature bending,dynamic modulus,high temperature rutting resistance and water stability of cold mix with different epoxy content were studied.The results show that epoxy resin can greatly improve the high temperature performance of CMA,but has no obvious effect on improving the low temperature performance.Compared with the traditional hot mix,the CMA with 10% epoxy dosage can meet the specification requirements at the low temperature performance,make the dynamic modulus can meet the wider temperature and frequency requirements,and have higher high temperature rutting resistance and water stability.Finally,10% epoxy resin dosage is the best mix ratio;(4)The CMA was used to pave test road,and no rutting,potholes,cracks and other diseases after 6 months.Rubber wheel rolling can extrude the moisture content of CMA more easily,reduce the porosity and increase the compactness,which is more suitable forcold mix pavement rolling construction.