Research On Preparation And Performance Of Rapid Hardening Sulphoaluminate Cement-Emulsified Asphalt Mixture

In order to improve the early strength of the emulsified asphalt mixture,the slow forming,and the inability to open traffic in time after the road potholes are repaired,this paper uses rapid hardening sulphoaluminate cement as an additive.Firstly select the three influencing factors of cement dosage,external water content and emulsified asphalt content,and design orthogonal test.Through range analysis and variance analysis,the influence degree of each factor on the performance of asphalt mixture is obtained,and get the initial mix ratio of the rapid hardening sulphoaluminate cement-emulsified asphalt mixture with three mineral aggregate gradations of AC-13,SMA-13 and LB-13.On the basis of the initial mix ratio,the amount of cement and the amount of water added were kept unchanged,and the Marshall test method was used to determine the optimal amount of emulsified asphalt for the three mineral aggregate gradations fast hardening sulfoaluminate cement-emulsified asphalt mixture.Combining the macro and micro analysis to study the strength development of rapid hardening sulphoaluminate cement-emulsified asphalt mixture.Control the content of rapid hardening sulphoaluminate cement to 2%,choose three mineral aggregate gradations(AC-13,SMA-13,LB-13),and at the same time use SMA-13 mineral aggregate gradation as the representative,change the ordinary cement and rapid hardening sulphoaluminate cement content,using immersion marshall test,freeze-thaw splitting test,wheel tracking test and low temperature bending test,to study the water stability,high temperature stability and low temperature stability of asphalt mixture under different conditions.The main research conclusions are as follows:(1)The cement dosage has the greatest impact on the emulsified asphalt demulsification time,the initial stability of the mixture and the molding stability,and the amount of emulsified asphalt has the greatest impact on the penetration force of the mixture.(2)The Marshall test method was used to determine the optimal emulsified asphalt dosage of three mineral aggregate gradations rapid hardening sulphoaluminate cement-emulsified asphalt mixtures.The optimal emulsified asphalt dosage of AC-13 asphalt mixture was 8.58%,SMA-13 asphalt mixture was 8.63%,LB-13 asphalt mixture was 7.34%.(3)Adding rapid hardening sulphoaluminate cement can greatly improve the early and late strength of the mixture.Whatever the gradation,what kind of cement content,cement on asphalt mixture early(1d,3d)strength enhancement effect is very significant,is conducive to road repair and open traffic as soon as possible.(4)When the rapid hardening sulphoaluminate cement content is 2 %,the water stability,high temperature stability and low temperature stability of SMA-13 graded asphalt mixture are the best.Taking SMA-13 gradation as the representative,the incorporation of cement can significantly improve the water stability and high temperature stability of asphalt mixture,and reduce the low temperature stability of mixture.However,in the range of 3% cement content,the low-temperature stability can still meet the specification requirements.(5)With the same cement content,the effect of rapid hardening sulphoaluminate cement on the water stability and high temperature stability of emulsified asphalt mixture is better than that of ordinary cement.