Study On Development And Performance Of High Elasticity Salt-containing Asphalt Mixture

In recent years,winter snow and ice disasters come up frequently in our country.Pavement anti-skid performance significantly reduces because the snowfall causes freezing on the road surface.This affects traffic safety meanwhile impacts people's normal travel inconvenience and seriously affect China's steady and rapid economic development.In order to clear the road ice and snow as soon as possible to restore traffic,the local Transportation Department usually adopts spreading snow deicing,artificial snow removal,mechanical snow removal.These passive snow removal methods are low efficiency,pollutant for ambient environment,threatened for human safety.Europe and the United States and other developed countries used salt containing pavement,high elastic pavement and other active ways.But they are high cost,limited and the deicing capacity is limited,which have restricted the active snow and ice technology to promote large-scale application.In this study,a composite snowmelt de-icing functional pavement material,high-elastic salt-containing asphalt mixture,was developed by combining salt-containing pavement and elastic road deicing and deicing.Firstly,based on the mechanism of declining freezing point at the interface and slow release technology,the function of each component of salt storage additive was clarified.The aim of this paper was to improve the deicing capacity of salt filler which was released slowly.Freezing point was tested by DSC method,and the optimal ratio of chlorinated salt was determined.The specific surface area of different carriers was tested by BET method.The carrier type was optimized according to the specific surface area.The Marshall specimen in the water was tested in the conductivity test.According to the law of the change of conductivity with time,the storage of salt filler composition and the proportion of the carrier determine was determined.Based on the demand for sustained-release salt storage salt,the storage of filler was carried the second hydrophobic modification.The criterion of determination of hydrophobic agent and the method of determining the content of hydrophobic agent were put forward by conductivity test method.In order to balance the melt deicing function and road performance of the mixture,the composition design and the road performance of the high elasticity storage salt asphalt mixture were studied.Based on the Marshall stability index and the road performance index,the optimum rubber particle content and the ratio of different storage filler were determined by the equal volume replacement method.The results show that the high and low temperature performance of high elasticity salt containing asphalt mixture can meet the requirements,but the storage of salt filler affects asphalt mixture more.The high storage salt filler can lead asphalt mixtures to lose their water stability.In order to evaluate the effect of snow melt and de-icing of high-elasticity salt-containing asphalt mixture,the surface ice-melting and interfacial adhesion test of the mixture were developed.The evaluation method of snow removal and deicing efficiency with drop time and shear strength was proposed.The spring back test was carried out to test the elastic modulus of the mixture under low temperature condition.Based on the distributed rutting instrument,the wheel load simulation test was carried out on the icing.The relationship between the elastic modulus and the deodorization effect of the mixture was determined.Based on the change of the conductivity with time,the snowmelt deicing durability of the mixture was evaluated.Combined with the snowfall in China,functional durability prediction formula was developed.Finally,based on the results of laboratory experiments,production process of high-explosive salt asphalt mixture was optimized.The matters needing attention of the compaction and mixing process was put forward.The requirements of the use of salt storage filler were put forward.Using these guides to pave Zhangcheng highway Chengde section and Zhangcheng highway Zhangjiakou section and the design of the test section and the road performance were studied.In the last effects of snowmelt deicing on the test section was analyzed and summarized.