Optimization And Research On Key Evaluation Indexes And Test Methods Of Salt-storage And Ice-resistant Materials

Winter road icing reduces the skid resistance of the road surface,which brings a major hidden danger to the safety of traffic,in order to reduce the safety impact of winter road icing,many studies have been carried out at home and abroad for road deicing,adding anti-icing materials method is one of the effective way.At present,China is using the anti-icing material specification for the industry standard "highway asphalt mixture with snow and ice melting material part 2: salt material"(JT/ 1210.2-2018),but in the use of the process found that the evaluation index in the specification has shortcomings.This paper supplements and optimizes the test methods and evaluation indexes of the key indicators of salt and anti-icing materials in the specification based on the experimental analysis.Firstly,AC-13 grade was used to design the composition of anti-icing asphalt mixture,determine the way of mixing salt anti-icing materials,and study the road performance of anti-icing materials under different mixing amounts through indoor tests,and compare the road performance with that of unmixed anti-icing materials.Secondly,the shortcomings of the evaluation index of salt release in the specification are analyzed by the experimental method,and it is pointed out that the salt release is related to the immersed area of the specimen and not to the shape of the specimen;the evaluation index of salt release is optimized,and the evaluation index of salt release per unit area is proposed.Combined with The law of number for dilute solutions,the freezing point of pavement under different rainfall conditions is predicted by unit area,and the influence law of temperature,admixture,asphalt type and void ratio on salt release per unit area is obtained by test.Then,a test method is proposed to evaluate the longevity of anti-icing materials by simulating the water scouring effect of anti-icing asphalt mixes indoors,which can achieve complete salt release from anti-icing asphalt mixes in a short period of time and evaluate the continuity and uniformity of the salt release process.At the same time,the test method is used to study the influence of asphalt type,admixture amount and grading type on the longevity of salt analysis and release.Finally,the salt release characteristics of anticaking asphalt pavement under rain and snow are studied by using magnetic stirrer,and the reasons for the difference between the long-lasting test method and the salt release characteristics of anticaking asphalt pavement are investigated;different temperatures are set to simulate the salt release characteristics of anticaking asphalt pavement under different seasons,and the influence of load is considered to obtain the formula for calculating the annual average salt analysis output of anticaking asphalt pavement,and a prediction model for the effective service life of salt storage anticaking asphalt pavement is established by combining with the long-lasting test method.