| Epoxy asphalt,as a kind of thermosetting material,fundamentally changes the thermoplastic properties of asphalt,and has much better physical and mechanical properties than ordinary asphalt,which has been widely used in road and bridge pavement engineering.However,the epoxy asphalt on the market needs a long maintenance period before it can be basically solidified after the completion of construction and reach the strength of vehicle carrying capacity.A long time of closed maintenance will lead to a significant delay in the time of open traffic.In view of this,this paper starts from the composition of epoxy asphalt,and develops early strength epoxy asphalt material,which can greatly shorten the curing time while ensuring its excellent road performance.First of all,based on the road with the performance of epoxy asphalt and the performance of construction into consideration,determine the type of each component of epoxy asphalt,and then put forward the principles and methods of comparison,considering the compatibility of the epoxy asphalt,mechanical properties,shelter and curing time,after the screening finally get early strength of the optimal proportion of each component in the epoxy asphalt.Then,the timetemperature characteristics of early strength epoxy asphalt binder were studied.The results showed that: when mixing at 10℃ ～ 40℃,the time for the viscosity of early strength epoxy asphalt binder to rise to 3Pa·s was greater than 120 min,meeting the actual construction requirements.After curing at 20℃ ～ 60℃,the early strength epoxy asphalt binder reaches its final strength within 20 h.Secondly,in combination with the performance requirements of epoxy asphalt mixture and the basis of this research,the gradation of epoxy asphalt mixture was determined,and the design method of Marshall stability was adopted to determine the optimum whetstone ratio of early strength epoxy asphalt mixture was 8.3%.Then,the road performance of four kinds of asphalt mixtures including early strength epoxy,domestic cold-mix epoxy,Japanese epoxy and American epoxy was compared and studied,including strength characteristics,high and low temperature stability,water stability and oil corrosion resistance.The results showed that the Marshall stability of the early strength epoxy asphalt mixture could reach 41.34 k N after it was maintained for 12 hours at normal temperature(25 ℃),which met the traffic strength requirements of the carrying vehicle,and the curing time was significantly shorter than that of the other three kinds of epoxy asphalt mixtures.Meanwhile,all other road performance met the requirements of the specification.Finally,based on the construction adaptability of early strength epoxy asphalt,the storage stability of components A and B at room temperature and the influence of aggregate moisture content on the performance of the mixture were studied,and the appropriate storage mode and the control value of aggregate moisture content of components A and B of early strength epoxy asphalt were determined.Combined with the time-temperature characteristics of the viscosity and the strength of the mixture,the control indexes of the construction capacity time and health cycle of the early strength epoxy asphalt mixture at different temperatures were determined.Based on the demand of curing time of epoxy asphalt concrete,this paper developed an early strength epoxy asphalt material with excellent road performance and significantly shortened curing time.At the same time,the road performance and construction performance of early strength epoxy asphalt mixture are explored,to provide some suggestions for the application in practical projects,and the curing mechanism and microstructure of the co-curing system at different curing stages need to be further studied. |
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