Study On Preparation Of Salt Storage Aggregate And Its Slow-release Snow Melting Performance

The transportation network formed by highway transportation is an important infrastructure to ensure convenient passenger transportation and smooth logistics,and it is related to social stability and economic development.The existence of extreme weather such as ice,snow and freezing rain will cause snow and icing of the road area,which will result in the low capacity of the road transportation network,affecting normal transportation and people’s driving safety.In severe cases,the road network will be closed and the road transportation will be trapped.In a state of paralysis,economic losses of hundreds of millions of yuan are caused every year due to the problem of freezing and snow accumulation.Therefore,it is necessary in order to use effective means to quickly eliminate road ice and snow and keep the road surface clean.Analyzing the current research status of self-melting snow pavement in China,it is found that the method of adding salt storage aggregate to asphalt concrete has attracted more and more attention.However,the research and development of salt storage aggregates as admixtures has always been restricted by the slow-release effect and cannot be truly put into practical engineering applications.Therefore,improving the slow-release performance of salt storage aggregates has important guiding significance for the development and engineering application of salt storage asphalt concrete pavement.In this paper,magnesite cement will be selected as the salt storage carrier,and a suitable modifier will be selected to modify the salt storage aggregate to improve its water resistance and compressive strength.Aiming at the problem of improving the slow-release performance of salt storage aggregates,a new type of salt storage aggregate with various components and proportions has been developed,and the results of crushing value test,contact angle test,carbon steel corrosion rate test and electrical conductivity test result analysis have been developed.,Which shows that glycerin-containing 4 salt storage aggregate has good corrosion inhibition performance and slow release effect.Comparing the road performance of Marshall specimens under different replacement rates of salt storage aggregates,the results show that:under the best oil-stone ratio,with the increase of salt storage aggregate replacement rate,its high temperature performance and low temperature performance meet the specification requirements,but When the salt storage aggregate replacement rate is 20%,the residual stability cannot meet the specification requirements,so it is determined that the optimal salt storage aggregate replacement rate is 15%.Based on the salt dissolution test,the conductivity of different mass concentrations of Ca Cl₂ solution was measured,and then the standard curve of salt dissolution of salt storage asphalt concrete was drawn,and the amount of salt analysis under different replacement rates of salt storage aggregate was estimated based on the conductivity test results It can be seen that the salt-storing asphalt concrete under the optimal replacement rate has a better slow-release effect.Simultaneously,the simulated rain erosion test was used to determine the quality change of Marshall specimens under different replacement rates within five years and the change of electrical conductivity after the test.The results show that the Marshall specimens after the simulated five-year rain erosion test still have better slow-release effects and deicing and snow removal performance when the optimal replacement rate of salt-storage aggregate is 15%.A visual survey method was utilized to observe the snow melting effect at the best replacement rate 15%.The results showed that when the temperature is above-3℃,the snow melting effect of salt storage asphalt concrete within 24 hours is better than that of asphalt mixed with salt storage aggregates.The concrete is good.According to the results of the freezing point test and melting rate test,the Marshall specimen under the best replacement rate has a freezing point of-5°C and a melting rate of 352g/（h?m²）,indicating that it has good deicing and snow melting performance.Through cost-effective analysis of ordinary asphalt concrete pavement and salt storage asphalt concrete pavement,it can be observed that the comprehensive cost-effectiveness of salt storage asphalt concrete is higher when the mixture gradation and asphalt use are the same.