Design And Performance Study Of Waterborne Epoxy Resin Modified Emulsified Asphalt Mixture

The poor late strength and performance of emulsified asphalt mixture pavement because of the low strength,the quality is unstable and the durability is not enough,and so on.In order to solve these problems,in this paper,emulsified asphalt was modified by waterborne epoxy resin to obtain high performance cold paved asphalt mixture with low energy consumption,low pollution,convenient construction,high cohesion and durability.Firstly,the content of curing agent in the modifier was determined and the comprehensive property of waterborne epoxy resin modified emulsified asphalt was comprehended by three indexes tests of evaporation residue of modified emulsified asphalt,and the content of waterborne epoxy resin modified emulsified asphalt was determined to be 10%.It was found that the comprehensive performance of evaporation residue of modified emulsified asphalt was better than that of emulsified asphalt.Then the high and low temperature properties of evaporation residue of modified emulsified asphalt with different waterborne epoxy resin content were studied by dynamic shear rheology test(DSR)and low temperature bending beam test(BBR).The results show that the high temperature properties of modified emulsified asphalt become better with the increase of waterborne epoxy resin content,but the low temperature properties become worse.According to analysis and research the results of dynamic shear rheology test(DSR)and low temperature bending beam test(BBR)based on SHRP specification,the modified emulsified asphalt with 10%waterborne epoxy resin was selected as the binder of asphalt mixture.To observe the microstructure of evaporation residue of modified emulsified asphalt with different waterborne epoxy resin content used scanning electron microscope.It was found that the spatial network structure was more comprehensive,more uniform and finer line type,and the overall performance of asphalt could be improved better when the waterborne epoxy resin content was 10%.The modified Marshall test method was used to design the mixture ratio of waterborne epoxy resin modified emulsified asphalt mixture AC-13C,and the optimum ratio of oil to stone was determined to be 9.0%.It was determined that the Marshall test pieces were formed by the two-stage molding method,that is,after the first compaction for 50 times and 24 hours of curing at 60℃,the second 25 times of compaction were carried out,then the mold was released after being stored at room temperature for 12 hours.Finally,by researching on the high and low temperature performance,water stability and fatigue properties of matrix asphalt,emulsified asphalt and modified emulsified asphalt mixture,it is found that the stability of modified emulsified asphalt mixture is better than the other two asphalt mixtures;The modified emulsified asphalt mixture has lower flexural tensile strength,but still has good low temperature performance;the water stability is slightly worse than the matrix asphalt mixture but is basically equivalent,and is much better than the emulsified asphalt mixture;Although the flexural strength is lower than that of the matrix asphalt mixture,its fatigue life is longer,indicating that the epoxy resin improves the durability of the mixture within the normal service life.According to the research on the construction performance of waterborne epoxy resin modified emulsified asphalt mixtu re,the mixing time of modified emulsified asphalt mixture was determined to be 180 seconds,the compactable time was 4 hours,and it was basically in line with the requirement of openin g traffic in a short time.