Study On Effect Of Chloride Storage On Salt Storage Asphalt Mixtures And Salt Storage Asphalt Binders And Characteristics Of Salt Transfer

Chloride salt storage asphalt pavement is adding salt chloride storage filler into the pavement to replace part of the mineral powder and salt precipitates from chloride salt storage fillers under the action of road load.Thereby,chloride salt storage asphalt pavement plays the role of snow removal and ice suppression.The chloride salt-storage asphalt pavement has excellent service functions,such as reducing environmental pollution,melting snow and ice suppression timely and effectively,long service life.Therefore,it is an ideal pavement type for enhancing winter road maintenance in China.However,with the large-scale application of chloride salt storage asphalt pavement to physical engineering,some of the chloride salt-storing asphalt pavements have problems such as stability,adhesion decreases rapidly,and snow melting years can not meet the design requirements and other issues.Therefore,this paper is aimed at the salt migration model and performance decay mechanism of chloride salt storage asphalt pavement,which has important guiding significance for physical engineering.From the perspective of decay mechanism and salt migration model of chloride salt storage asphalt pavement,this paper firstly determined that the proportion of chloride salt storage filler instead of mineral powder was 0%,35%,70%,100%,then the chloride salt storage filler was mixed into asphalt cement and asphalt mixture.The cone penetration test and DSR temperature sweep test were used to analyze the effect of chloride salt storage on the shear strength and high temperature stability of asphalt binders.The low temperature creep test was carried out by MTS tester to determine the effect of chloride salt storage on the low temperature crack resistance of asphalt binders.The contact angle measurement test and the improved water boiling test were used to determine the effect of the salt storage filler on the asphalt-aggregate adhesion performance.Secondly,the stability and volume index of different mixed chloride salt storage asphalt mixtures were compared to determine the decay mechanism of the chloride salt storage asphalt pavement.Finally,the chloride ion content of the salt residue was tested by the chloride ion measurement test,using matlab software to carry out programming simulation and explore the migration model of chloride salt storage asphalt pavement.The research indicated that the addition of chloride salt storage filler reduced the shear resistance of the salt-filled asphalt cement;the DSR temperature sweep data showed that the phase angle of the salt-filled asphalt cement increased and the rutting factor decreased,indicating that the addition of the chloride salt storage filler increased the viscosity of the asphalt cement and reduced the high-temperature performance of the chloride salt storage asphalt binders;the low temperature creep test showed that the addition of chloride salt storage filler would reduce the asphalt rubber deformation and the low temperature crack resistance,but the reduction was not large,the salt filler had little effect on the chloride salt storage binders.In the absence of water,the higher the proportion of chloride salt storage fillers,the greater the adhesion performance of asphalt binder-aggregate,and higher than the adhesion of matrix asphalt-aggregate;in the presence of water,the chloride salt storage asphalt-aggregate adhesion performance decreased with increasing mixing ratio,contrary to the anhydrous condition,indicating that water was a key factor in changing the adhesion of the chloride salt storage asphalt.In the water bath at 20 ° C,40 ° C,60 ° C,the increase of void ratio was the same,and the inflection point was generated at 7 days,and the void ratio after 7 days was relatively flat.This was the same as the analysis of the stability change of asphalt mixture,indicating that the unstable salt inside was basically precipitated,and the internal structure of the chloride saltfilled asphalt mixture turned stable.Using the principle of diffusion coefficient to measure the diffusion coefficient in the case of 0d,1d,3d,combined with Fick's second law to establish the migration model of chloride ion in the chloride salt storage asphalt mixture,the matlab software was used to simulate the migration of chloride ions at different distances.