Experimental Study On Performance Of Basalt Fiber Permeable Asphalt Mixture

Permeable asphalt mixtures are widely used for their excellent water permeability,good rutting resistance and noise reduction effects,but some road surface diseases are caused by natural factors and driving loads.Adding additives such as polymers and fibers to the asphalt mixture has become one of the effective technical means to solve this problem.As a new type of mineral fiber,basalt fiber has been widely used as an asphalt mixture additive in recent years,but it has rarely been reported in the application of permeable asphalt mixture.Therefore,the influence of basalt fiber on the performance of permeable asphalt mixture needs to be comprehensively studied.In this paper,the rheological properties and road performance of basalt fiber asphalt and its permeable asphalt mixture were studied by laboratory tests.The influence and mechanism of basalt fiber on the performance of permeable asphalt mixture were investigated.Firstly,based on the basic properties of raw materials such as asphalt,high viscosity modifier and basalt fiber,basalt fiber asphalt was prepared.The rheological properties of basalt fiber on asphalt were analyzed by dynamic shear rheological test and multiple stress creep recovery test.The results show that the addition of basalt fiber,the complex modulus of SBS modified asphalt increases,the phase angle decreases,G*/sin? increases,and the values of R0.1 and R3 2 increase to different degrees,but the increase is smaller.Under the action of higher stress,the cumulative creep strain of asphalt is higher,the values of Jnr0.1 and Jnr3.2 are reduced to different extents,and the basalt fiber improves the PG high temperature grade of asphalt.Secondly,the design of basalt fiber permeable asphalt mixture with PAC-13 grade was carried out.The influence of basalt fiber on the ratio of permeable to asphalt mixture was analyzed by leak test.Based on this,the best oil-stone ratio of permeable asphalt mixture was determined.Furthermore,the effects of basalt fiber on the stability,flow value,void ratio,connected void ratio,scattering loss and leakage loss of the permeable asphalt mixture were studied.The results show that the optimum oil-stone ratio of basalt fiber permeable asphalt mixture increases with the increase of the length of basalt fiber,and the fiber improves the stability and flow value of the permeable asphalt mixture,reducing the leakage loss and scattering loss,and has little effect on the void ratio.Thirdly,on the basis of the above research,the basalt fiber pair permeable asphalt mixture is analyzed by rutting test,freeze-thaw split test,water-immersed Marshall test,low temperature indirect tensile test,low temperature trabecular bending test and four-point bending fatigue life test.The influence of road performance and the correlation between the rheological properties of fiber asphalt and the high temperature performance of permeable asphalt mixture.The results show that basalt fiber can improve the rutting resistance,low temperature crack resistance,water stability and fatigue resistance of permeable asphalt mixture.Finally,the typical sample of indirect tensile fracture zone is selected as the research object.The mechanism of the performance of basalt fiber reinforced asphalt mixture is analyzed from macroscopic and microscopic perspectives.The results show that the fracture morphology of permeable asphalt mixture can reflect its mechanical properties.The microscopic image shows that the basalt fiber is distributed in three-dimensional disorder in the asphalt mixture,forming a local spatial network structure,which has a significant effect on the reinforcement of the asphalt cement and improves the mechanical properties of the permeable mixture.The research results of this paper provide reference for the design and application of basalt fiber suitable for drainage asphalt pavement engineering,and have certain theoretical research significance and popularization and application value.