Study On Preparation Technology Of Quick-drying SBR Modified Emulsified Asphalt Sealing Mixture

In the humid and rainy areas of southern China,the emulsified asphalt road surface sealant mixture has a long open traffic time,which restricts the promotion and application of the emulsified asphalt sealant mixture.In order to solve this problem,based on the comprehensive research at home and abroad,this paper intends to use cement and carbon fiber powder as fillers and additives for sealant mixture,and study the road performance and open traffic time of SBR modified emulsified asphalt mixture.Thus,A quick-drying SBR modified emulsified asphalt sealant mixture can be prepared.Firstly,the SBR modified emulsified asphalt is prepared by the production method of emulsification and modification.By studying the influence of three emulsifiers of CMK-30,CMK-50 and quaternary ammonium salt 1631 on the three major indexes and storage stability of emulsified asphalt evaporation residue,the best type and dosage of emulsifier and stabilizer were determined.Then,by studying the effect of different amount of SBR latex on the performance of modified emulsified asphalt,the optimal preparation scheme of SBR modified emulsified asphalt was determined.Secondly,the effects of modified emulsified asphalt,added water,cement and carbon fiber powder on the road performance of the sealant mixture were respectively studied by orthogonal test method.The optimum dosage of modified emulsified asphalt was 12%,and the water consumption was 13%.Cement and carbon fiber powder in the selected horizontal range,the corresponding indicators meet the requirements of the specification.Then,the influence of ordinary Portland cement and fly ash cement on the molding time of the sealant mixture was studied by the cohesion test.It was concluded that the use of 4%ordinary Portland cement can be opened two hours earlier than without cement.Finally,through the study on the control effect of carbon fiber powder,it is found that for 2%to 5%cement content,when the carbon fiber powder is 4%,the line crack rate and surface crack rate are the smallest.The comprehensive analysis shows that the optimum formula of the sealant mixture prepared in this paper is:12%of modified emulsified asphalt,13%of added water,4%of portland cement,and 4%of carbon fiber powder.Finally,the apparent morphology of cement emulsified asphalt slurry was studied by scanning electron microscopy(SEM).The 4%cement content of SBR modified emulsified asphalt slurry has the best dense three-dimensional network structure,and the mixture formed has the best strength,which bring the best quick-drying effect.The carbon fiber powder particles with 4%carbon fiber powder content are best coated by the mixture and have the best crack control effect.The product of cement-modified emulsified asphalt slurry was studied by infrared spectroscopy(FTIR).It was found that cement and modified emulsified asphalt did not produce new substances.The formation of quick-drying was the process of"water consumption" of cement hydration.The mechanism of carbon fiber powder cracking control was studied.It was found that carbon fiber powder essentially achieved the effect of controlling cracking by affecting the hydration of cement and combining physical bonding.The economic analysis was conducted and shows that the the quick-drying SBR modified emulsified asphalt mixture has the characteristics of low cost and suitable for promotion.