| With the rapid development of tourism,the forest-grassland ecotone in Inner Mongolia Autonomous Region has attracted a large number of tourists because of its unique landform and rich natural landscape.However,summer is the peak tourist season in this area,with a large increase in tourists and traffic,and less traffic in winter.This situation makes the use of roads in the forest-grassland ecotone unbalanced.In the hot and humid summer,the sharp increase in vehicle load will cause various diseases such as rutting,which seriously affect the comfort of road use and the development of tourism in this area.Epoxy asphalt is a mixture of epoxy resin,asphalt,curing agent and other additives.Compared with other modified asphalt,epoxy asphalt is a green and excellent pavement building material with excellent thermal stability,rutting resistance and durability,which is widely used in steel bridge deck pavement.However,due to its large amount and high cost,its use on roads is limited.In this thesis,on the premise of ensuring that the low epoxy modified asphalt meets the basic road performance,the influence of low epoxy asphalt content on the rheological properties of asphalt is explored through laboratory tests.The research results are as follows:(1)According to the softening point,penetration,ductility and viscosity tests of epoxy asphalt,it is shown that epoxy resin and curing agent can improve the high temperature stability of asphalt.When the content of epoxy resin and curing agent is 6%,the high temperature performance of epoxy asphalt is better.(2)According to the strain scanning,when the strain is 1%,the modified asphalt with different content is in the linear viscoelastic range,and the temperature scanning and frequency scanning tests are carried out based on the linear viscoelastic range.The main curve of asphalt frequency-complex shear modulus is established according to the principle of time-temperature equivalence,and the CAM model is constructed.The results show that:Epoxy resin can significantly improve the rutting factor and complex shear modulus of asphalt,and reduce the phase angle.6%epoxy asphalt has better high temperature stability and shear deformation resistance.The complex shear modulus increases with the increase of frequency,and the main curve in a wide range of temperature and frequency can be obtained according to the principle of time-temperature equivalence.The CAM model has a high degree of fitting for the main curves of different epoxy asphalt.(3)According to the multiple stress creep test(MSCR),with the increase of epoxy resin content,the deformation recovery ability of asphalt is continuously improved,the irrecoverable creep compliance is decreasing,and the deformation resistance of asphalt is continuously enhanced.Epoxy resin can promote the recovery deformation ability and high temperature stability of asphalt.(4)According to linear scanning and linear amplitude scanning(LAS)tests at medium and low temperature,and the damage characteristic fitting model established by visco-elastic continuous damage theory(VECD),the influence of epoxy resin on asphalt fatigue resistance is analyzed.The results show that adding epoxy resin can improve asphalt modulus and asphalt anti-deformation ability,but with the increase of epoxy resin content,the improvement effect of asphalt modulus increases first and then decreases,and there is an optimal value of anti-deformation ability.With the increase of strain level,the fatigue life of asphalt is seriously attenuated.Compared with other modified asphalt,the fatigue resistance of asphalt with epoxy resin content between 4%and 7%is better.(5)The changes of microscopic image and 3Dsurface image show that when epoxy resin and curing agent are distributed evenly and in micro-flocculent structure,epoxy resin can fully swell in asphalt and excite uniform fluorescence;Through the statistical analysis of particles,it is found that the enhancement effect of epoxy resin and curing agent on the high temperature performance of asphalt originates from the distribution of particle area above 26.7346μm~2. |
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