Preparation And Properties Of Epoxy Asphalt And It's Mixture

An extensively concerned problem in engineering is how to design pavement on long span steel deck. Epoxy asphalt concrete, with better high-temperature stability, low-temperature anti-cracking performance and fatigue resistance, is a comparatively good materials for paving orthotropic steel decks. But there are the obvious differences between asphalt and epoxy resin such as polarity, molecular weight, density, viscosity, solubility coefficient and so on. It leads to low compatibility between epoxy resin and asphalt. Common epoxy resin is a brittle materials and lack ductility after cured. Dense gradation asphalt mixture was selected to pave steel decks for good anti-permanent deformation and anti-water damage. Thus, the paving layer show bad skid resistance. In addition, the processing technology difference between laboratory test and field construction make it is difficult to evaluate the epoxy asphalt mixture performance. Therefor, it is very importance to improve the ductility of epoxy asphalt, the compatibility betweent epoxy resin and asphalt, the curing processing in laboratory, the anti-skid performance of epoxy asphalt mixture, and the durable of paving layer on orthotropic steel decks. The primary goal of the present study is to prepare a epoxy asphalt with better pavement performance using the homemake epoxy resin and asphalt, improve compatibility and elongation at break of epoxy asphalt. Epoxy asphalt mixture with better close-grained and anti-skid performance was prepared by optimizing the aggregate blending and curing processing. And the rheological character of asphalt, viscoelastic properties and fatigue of epoxy asphalt mixture was investigated. The following conclusions are obtained:1. The surfactant was employed to decrease the interfacial tension of epoxy resin/asphalt and improve the compatibility between epoxy resin and asphalt. An epoxy asphalt with better compatibility and homogeneous was prepared.2. The styrene-butadiene-styrene triblock copolymer(SBS) was adopt to improve the flexility of epoxy asphalt. Preparation of epoxy asphalt with high strength, good high-temperature stability and ductility using common domestic diglycidyl ether of bisphenol A epoxy resin and asphalt become reality. And the cost of epoxy asphalt production was reduced.3. Methyl tetrahydro phthalic anhydride (MTHPA) with slow reaction and long using period was employed to prepare epoxy asphalt. It is favourable to pave epoxy asphalt mixture. And the curing reaction of epoxy asphalt occure not only at high temperature but also at room temperature. It is important to assure epoxy asphalt mixture fully cured after paving.4. The relation between epoxy resin contents and mechanical properties is nonlinear. The mechanical properties revealed that the tensile strength increased slowly when the contents of epoxy resin less than 30 wt %. when epoxy resin contents more than 30 wt %, the tensile strength increased significantly.5. The high-temperature performance of apshalt was improved remarkably by epoxy resin. The performance grade at high temperature enhance approximate 30℃when 20 wt% epoxy resin added in asphalt. Compared to SBS modified asphalt, the complex modulus of epoxy asphalt have increased by roughly one or two order of magnitude.6. The relationship of complex modulus and temperature can be charcterized by Arrhenius equal and WLF equal in the temperature range from 30 to 100℃. The viscoelastic of epoxy asphalt was improved by epoxy resin. Burgers model is more suitable for the viscoelastic property research of epoxy asphalt, the model demonstrate that epoxy resin can improve the high-temperature anti-permanent deformance.7. The performance of epoxy asphalt and its mixture showed different trend growth between laboratory curing in oven at 120℃and field curing. The mechanical properties increase slowly in the earliest stages of curing, then increase rapidly. But it is increase steadily throughout the curing.8. Marshall stability and indirect tensil strength increase with epoxy resin contents increasing under the same ratio of asphalt to aggregate. The effect of the ratio of asphalt to aggregate on void, voids in mineral aggregate and voids filled with asphalt is little.9. If the traffic volume in road design was set 1×10~7, the tensile strength structure parameter of SBS modified asphalt mixture is 3.64 and it is 1.81 for 20 wt% epoxy resin modified asphalt mixture. It demonstrated that the high-temperature performance and anti-fatigue of paving layer on steel decks was improved, and the thickness of paving layer was decreased remarkably.10. The deformation resistance of asphalt mixture was improved by epoxy resin. The totall deformation of epoxy asphalt with 20, 35 and 50 wt% epoxy resin is 40.7%, 26.4% and 21.0%, respectively. Compared with SBS modified asphalt, the permanent deformation is 45.2%, 20.0% and 16.1%.