Preparation And Properties Of Epoxy Asphalt Materials Used In Steel Deck Pavement

Epoxy asphalt has excellent mechanical and pavement performance,it is the preferred material for orthotropic steel deck pavement.However,most of the epoxy asphalt used in our country is imported from abroad,the material recipe is protected by the intellectual property rights,the price is high,which not only greatly increases the construction cost of bridge,but also is not conducive to the further application of the use.Based on the above reasons,a kind of epoxy asphalt materials with low cost and excellent comprehensive performance were prepared by self-made modified amine curing agent and compound epoxy resin in this paper.The curing kinetics of epoxy asphalt and the pavement performance of epoxy asphalt mixture were also studied.The main research contents and conclusions are as follows.The optimization of screening method composed of epoxy asphalt design,through three stages(exploration stage,optimization stage,verification stage)rounds of selection and gradual optimization.Finally,comprehensive consideration of performance and cost,the optimal ratio of curing agent,epoxy resin and asphalt is 1.0:4.2:6.0.According to the construction requirements of the epoxy asphalt reserved time to determine the mixing temperature is 120 oC.The microstructure of epoxy asphalt was studied by fluorescence microscopy.When the amount of curing system increases to 45%,the phase inversion occurred,and the epoxy system is a continuous phase and the asphalt is dispersed.The curing kinetics of epoxy asphalt was studied by differential scanning calorimetry(DSC).Based on the analysis of DSC curve,the three critical control temperatures of the curing process were the gelation temperature of 81 oC,the curing temperature of 118 oC,and the post-treatment temperature of 161 oC.The activation energy Ea,the pre-exponential factor A,and the reaction order n was obtained by Kissinger and Crane equation.The curing kinetic equation was determined,and modified by the measured data.The revised equation is d??dt = 35954.16e-42020/RT(1-?)1.21,which can predict the curing reaction process.According to Marshall test design method,the physical and mechanical properties of epoxy asphalt mixture was tested and analyzed.It is determined that the optimum asphalt aggregate ratio is 6.2%.The pavement performance of mixture was evaluated by Marshall test,wheel rutting test,low temperature bending test,water stability test,corrosion resistance test and bending fatigue test.The results showed that the all performance indexes of self-made epoxy asphalt mixture meet the specification requirements.The high temperature performance of mixture is comparable to that of American and Japanese epoxy asphalt.Low temperature performance of mixture is slightly lower than domestic and American epoxy asphalt.The resistance to freeze-thaw damage ability and fatigue life of mixture is only lower than Japanese epoxy asphalt.In addition,the self-made epoxy asphalt compared with other epoxy asphalt,its cost is the lowest,only 1.22~1.43 million yuan per ton.The material performance and cost were considered synthetically,the self-made epoxy asphalt has superior cost performance.