Key Technology Research Of High Explosive/Salt Storage Asphalt Mixture

Ensuring driving safety in ice and snow weather is always a difficult problem for transportation industry.Over the years,transportation industry researchers all over the world have explored many ways to remove snow and ice on roads.In the direction of material,snow and ice melting technology mainly includes adding salt storage materials into asphalt mixture to form salt storage asphalt pavement and adding high elastic material into asphalt mixture to form high elastic asphalt pavement.Salt storage asphalt pavement has a good effect on melting snow and ice,however,due to the existence of snowmelt agent,the road performance of asphalt mixture will be affected to some extent.The high elastic asphalt pavement has certain selfstress de-icing effect and good road performance.This paper attempts to combine salt storage materials and high elastic materials together,forming a comprehensive de-icing technology of salt storage and high elastic asphalt pavement with melting ice and self-stress de-icing performance to achieve better snow and ice melting performance.In this paper,main technical properties of salt storage materials and high elastic materials,composition design of high elastic and salt storage asphalt mixture,the influence of salt precipitation on the properties of asphalt mixture,effect evaluation and timeliness of snow and ice melting performance,ice-breaking characteristics and influencing factors of high elastic materials are studied systematically.The main research work is as follows:(1)The main technical properties of MFL and rubber particles were studied in this thesis.It provides the material characteristics support for the subsequent asphalt mixture design and research work.At the same time,the mechanism of melting ice-snow was analyzed.(2)On the basis of optimum gradation composition of common AC-13 asphalt mixture,considering the road performance and melting ice performance of asphalt mixture,we drawed the conclusion that the optimal amount of snowmelt agent is 80%.On the basis of the optimum gradation composition of the salt asphalt mixture,through the method of volume replacement,at the same time,considering the influence of rubber particle content on the road performance of asphalt mixture,we obtain that the reasonable content of rubber particles is 3%.Because of the incorporation of rubber particles,the pavement performance of asphalt mixture has decreased,but using high viscosity modified asphalt has obvious improved road performance of asphalt mixture.(3)The road performance of two kinds of asphalt mixture are studied with the change of immersion time.The results shows that with the gradual precipitation of salinization products,the low temperature performance and water stability performance of asphalt mixture decreased significantly,but it has little effect on high temperature performance.(4)This study designed four test methods to evaluate the effect of melting ice of asphalt mixture,and corresponding quantitative indicators were put forward for each test method.According to the test results,comparing with ordinary asphalt mixture,high elastic and salt storage asphalt mixture show obvious restraining freezing and snow melting effect,and the higher the amount of snowmelt agent,the more obvious the effect of melting ice.Based on salt dissection test,we know that the higher temperature or the greater the porosity of the mixture,the faster the salt precipitation rate in asphalt mixture.At the same time,the evaluation model of the performance time of melting ice is proposed,Then taking the weather condition of nearly 30 years in Nan Chang city as an example,we can get that the effective ice melt period of high elastic and salt storage asphalt pavement is 4.2 years.(5)Establishing the finite element simulation model of high elastic and salt storage asphalt pavement,de-icing features of rubber particles are studied.It is known that due to the existence of rubber particles,the stress state of the ice sheet in the road surface is changed.Therefore,the high elastic and salt storage asphalt pavement has certain self-stress deicing performance.And on the premise of ensuring the road performance of asphalt mixture,increasing the content of rubber particles or choosing rubber particles with larger size can make deicing performance more obvious.But when the ice on the road surface reaches a certain thickness or under too low temperature,the rubber particle will lose it self-stress de-icing performance.