| During the long-term service of asphalt pavement,especially under the combined effects of heavy loads,overloads,and extremely harsh environments,the pavement may suffer from partial diseases such as potholes,looseness,rutting,and cracking,which affect road traffic safety and driving comfort.At present,road surface diseases are usually repaired using hot mix asphalt mixture within a certain range of the damaged location.However,using hot repair technology to repair localized road surface diseases faces issues such as high energy consumption and large emissions of harmful gases.The microwave heating asphalt mixture technology can quickly repair pavement diseases,achieve rapid maintenance,and reduce repetitive repairs.While warm mix technology can effectively decrease the mixing and compaction temperature of asphalt mixture,and reduce the emission of harmful gases.Therefore,this article combines microwave heating technology with warm mix asphalt mixture technology to develop pavement materials suitable for small-scale and localized disease repair on the road surface.During the research process,steel slag was used to replace mineral materials to enhance the microwave heating rate to prepare a warm mix SBS-modified asphalt steel slag mixture,and its pavement performance was studied.The specific work includes:Firstly,the indicators of raw materials such as asphalt binder,amphibole and steel slag,warm mix agent and mineral powder were tested and evaluated to analyze the feasibility of the selected raw materials for the preparation of microwave-heated SBS-modified asphalt mixture.Through experiments on the types and dosage of warm mix agents,the type of warm mix agent was determined to be the Sasobit.Sasobit significantly improves the high-temperature index of SBS-modified asphalt,with little impact on low-temperature ductility and equivalent brittleness point,and its optimal dosage is 3%.Based on the requirements of the specifications and the viscosity-temperature curve,the mixing temperature of warm mixed SBS-modified asphalt mixture was determined to be 165℃ and the compaction temperature to be 155℃.Secondly,by studying the heating characteristics of different types of mineral materials,discover the microwave heating efficiency of steel slag as an absorbing material is significantly higher than that of natural aggregates.Under the same conditions,the heating rate of coarse steel slag is 1.4 times that of diorite,and that of fine steel slag is 5.9 times that of limestone.Subsequently,microwave heating and conventional oven heating were carried out to study the road performance of warm mix SBS-modified asphalt mixture,determine its mineral gradation and asphalt content,and analyze the effect of microwave heating and oven heating under two heating methods,warm mix agent and steel slag on the high temperature rutting resistance,low temperature cracking resistance,water stability,impermeability and wear resistance.Compared with the traditional oven heating technology,the microwave heating method improves the rutting resistance at high temperature,crack resistance at low temperature,water stability and impermeability of the warm mix asphalt.The characteristics of steel slag with good wear resistance and strong alkalinity improve the rutting resistance at high temperature,cracking resistance at low temperature,water stability and abrasion resistance of the warm mix asphalt,and its porous property reduces the permeability resistance of the warm mix asphalt.When the content of warm mix is 3%,the warm mix asphalt has better rutting resistance at high temperature compared with the ordinary hot mix asphalt,but the addition of warm mix decreases the water stability,low temperature crack resistance and impermeability of the asphalt mix.Finally,three material groups were determined as coarse steel fine stone type(SSL),coarse steel fine steel type(SDS),coarse steel fine steel type(DSS).Finally,the economic,environmental and social benefits of microwave heating of SBSmodified asphalt steel slag mixture were evaluated.The results show that compared with ordinary hot mix asphalt,warm mix SBS modified asphalt steel slag mixture has better pavement performance,and more significant economic,environmental and social benefits.The research results of this paper can provide a kind of fast,low cost and environmentfriendly pavemen repair material for road maintenance,which is of great significance and use value to improve the level of road maintenance,reduce maintenance cost and extend the service life of roads... |
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