Development And Deicing Performance Of Salt Storage Rubber Particle Asphalt Mixture

Snow in winter has caused serious snow and icing problems on many roads and urban roads.Pavement icing not only affects traffic safety,but also reduces road capacity and transportation efficiency,which has a serious impact on road safety and economic development in China.Salt storage rubber granular asphalt mixture has high elasticity and certain chemical freezing resistance,which can improve the condition of pavement icing to a certain extent.But at present,the research on mix design and pavement performance of salt-storage rubber granular asphalt pavement at home and abroad is still insufficient.In addition,there is no unified evaluation method for anti-freezing and deicing effect research.Based on the existing problems,the following research is carried out in this paper:(1)Mix design of salt storage rubber granular asphalt mixture.In this paper,a more compact gradation is determined by step-by-step filling method.Based on the volume design method,the oil-stone ratio is initially determined under the conditions of given target porosity,coarse-fine aggregate ratio,anticoagulant and mineral powder ratio.Finally,the optimum oil-stone ratio is determined by Marshall test.Through the study of Marshall index and compaction performance under different rubber particle content and particle size conditions,it is found that the bigger the rubber particle content is,the bigger the particle size is,the more difficult the compaction is in the construction process,but it is easier to deform under the action of automobile load after open traffic;the smaller the rubber particle content is,the smaller the particle size is,the easier to be compacted in the construction stage and open traffic.The latter is more resistant to deformation.In addition,with the increase of rubber particle size and content,it will have a negative impact on Marshall's indicators.(2)Study on road performance of salt storage rubber granular asphalt mixture.The influence of rubber particle size,rubber particle content and the amount of anticoagulant on pavement performance was quantitatively reflected by orthogonal experiment.The results show that the amount of anticoagulant ice agent has the greatest influence on the water stability and high temperature stability of asphalt mixture,and the amount of rubber particle has the second effect;for the low temperature crack resistance,the greatest influence is the amount of anticoagulant ice agent.The amount of rubber particles,and the amount of anticoagulant ice agent hasthe second effect.(3)Deicing performance of salt storage rubber granular asphalt mixture.The effect of chemical anti-freezing is realized by the precipitation of salts.The precipitation of salts is closely related to the mixing method of anticoagulants,the thickness of pavement and the void fraction of mixture.The results show that the precipitation rate is the fastest when anticoagulants are added in the form of additives.With the increase of void fraction,the effective thickness of salt analysis will increase,and the chemical anti-freezing effect will play a role.The effective temperature is above-4 C.After 10 simulated rainfalls,the amount of salt precipitation will decrease greatly and tend to be stable,but the performance of freezing resistance will continue.When the temperature drops below-4 C,only physical deicing performance can be used to achieve ice breaking.Within the range of rubber particle size,the larger the rubber particle size,the better the ice breaking performance.When the temperature drops to-6 C,the physical deicing effect will disappear.