Numerical Simulation Of The Influence Of Basalt Fiber On The Performance Of Asphalt Mixture

With the rapid increase of traffic volume and traffic load in China,asphalt pavement is facing obvious problems such as channelization,large traffic volume and heavy load,which makes asphalt pavement appear a lot of early diseases.The incorporation of basalt fiber has obviously improved the overall mechanical properties of asphalt concrete.At present,the research on the application of fiber in asphalt mixture mostly studies its road performance through experiments,which can not realize the different distribution orientation of fiber.Therefore,through the combination of finite element simulation and laboratory test,this paper carried out a numerical simulation study on the impact of basalt fiber on the performance of asphalt mixture.In this paper,the random distribution of basalt fibers in space is realized by using rand function in MATLAB program and VBA in AutoCAD,and the three-point bending beam model of basalt fiber random distribution in asphalt mixture is established by using ABAQUS,and the rationality of the beam model of basalt fiber asphalt mixture is verified by three-point bending test in laboratory.Secondly,through the numerical simulation of the performance of fiber-reinforced asphalt mixture,the influence of different parameters of basalt fiber on the flexural-tensile performance of asphalt mixture and the sensitivity analysis of influencing factors are analyzed.The results show that the maximum tensile stress of asphalt mixture with random fiber distribution is between the fiber horizontal distribution and 45° oblique distribution.Considering the economy and the uniformity of mixing,it is concluded that the best content of basalt fiber and the best length-diameter ratio are 0.3%and 35(fiber length is 6mm),respectively.The increase of basalt fiber modulus has little effect on the maximum flexural-tensile stress at the bottom of asphalt mixture.Range analysis and variance analysis show that basalt fiber content has the greatest impact on the flexural-tensile properties of asphalt mixture,followed by the fiber length-diameter ratio,and the fiber modulus has the least impact on the flexural-tensile properties of asphalt mixture.Lastly,from the SEM of the flexural-tensile fracture of the beam bending test,it can be seen that there are two kinds of pulling damage modes in the basalt fiber asphalt mortar:the damage of cohesion between the basalt fiber and the asphalt mortar and the damage of cohesion of the asphalt mortar itself.Based on the cohesive element,two kinds of pulling damage models of basalt fiber and asphalt mortar are established,and the influence of different parameters of the interface layer between fiber and asphalt mortar and asphalt mortar on the pulling characteristics of fiber is analyzed.The results show that it can not only improve the pull-out performance by changing the strength and fracture energy of the interface layer,but also improve the pull-out performance by changing the strength and fracture energy of the asphalt matrix itself.The research results provide a basis for basalt fiber to improve the performance of asphalt mixture,and also provide a reference for basalt fiber to improve the performance of asphalt mortar.