Research On The Damage Characteristics Of Basalt Fiber Asphalt Mixture Under Water-temperature Coupling

In the northeastern seasonal frozen area,the winter temperature is low and the summer is hot and dry,the freezing and thawing effect of autumn to winter and winter to spring is significant,and the road surface is seriously damaged by water and temperature coupling because of the scouring effect of summer precipitation.So improving the asphalt pavement in the frozen area of water-temperature coupling damage has important practical significance.Based on ?The research on the damage characteristics and mechanism of basalt fiber asphalt under water-temperature coupling?,this paper studies the characteristics of basalt fiber asphalt mixture damage under water-temperature coupling,and provide reference for the design optimization and popularization of basalt fiber asphalt pavement.The main contents of this paper are as follows:1.Designing the optimum ratio with different basalt fiber content and testing the road performance,then we can determine the optimum basalt fiber content.Mixing 0.0%,0.2%,0.3%,0.4% and 0.5% basalt fibers into the asphalt mixture,testing the Marshall physical index and mechanical index,thus we can determine the optimum aspect ratio for each fiber content.When the content of basalt fiber was 0.4% and the optimum aspect ratio was 5.4%,the road performance of asphalt mixture reached the comprehensive optimal value.2.Determining the laboratory test conditions for water–temperature of basalt fiber asphalt mixture.According to the climatic characteristics of the northeastern frozen area,road-surface temperature curve was drawn based on the calculated outdoor temperature data.Using "time-temperature" equivalent principle to determine the indoor temperature and time conditions and converting into indoor precipitation according from the collected precipitation data.Ultimately determining the long-term water-temperature coupling under the laboratory conditions.3.Researching the damage characteristics of asphalt mixture under water-temperature coupling.The porosity test,the splitting strength test and the indirect tensile test were carried out on the asphalt mixture marshall specimen with different water-temperature coupling cycle damage,then we analysis the attenuation law on asphalt mixture volume index and mechanical performance with water-temperature cycles,analysing the effect and reason of the mixture on the ability to resist water-temperature damage after adding the basalt fiber.4.Asphalt mixture water-temperature cycle damage model was established.Based on the logistic method,damage model of asphalt mixture was established,quantitative analysing of the damage degree and damage rate of asphalt mixture with the change of water-temperature cycle;based on gray theory,the damage prediction model of two-variable MGM(1,2)and three-variable MGM(1,3)was established,the damage prediction accuracy of different models was compared,which can provide reference for predicting the trend of long-term water-temperature damage of mixture volume index and mechanical index.