Study On The Relationship Between The Basalt Fiber Mixing Length Gradation And Asphalt Mixture Skeleton Sructure Characteristic Parameters On CT Images

In recent years,due to the similarity of the composition and the aggregate.the matching of the mechanical parameters with the asphalt binder.the better adhesion to asphalt than other fibers.outstanding aging resistance.recyclable utilization,especially the significant labor resistance of the asphalt mixture.etc..Basalt fiber became an effective asphalt mixture reinforcement.and began to be widely used in highway engineering.The grading design of AC-13 is carried out in this paper,and the best oil-stone ratio corresponding to AC-13 grading is 4.8%.and the best oil-stone ratio with 0.3%basalt fiber is 5.0%.The addition of basalt fiber changes the solid content in the asphalt mixture,and its distribution space and distribution form are affected by the skeleton structure of the asphalt mixture.However,the current research on fiber asphalt mixtures still stops at adding quantitative or fixed-length fibers.It is impossible to reveal the relationship between fiber length and the skeleton structure of asphalt mixture.The research results show that basalt fibers of different lengths have a great impact on the mechanical properties and road performance of asphalt mixtures.Therefore,if you want to improve the quality of asphalt pavement and extend its service life,you need to adjust the length of basalt fiber and asphalt mixture.In-depth study of the relationship between the material skeleton structure.The grading design of AC-13 is carried out in this paper,and the best oil-stone ratio corresponding to AC-13 grading is determined to be 4.8%.When the basalt fiber content is 0.3%.the best oil-stone ratio of asphalt mixture is 5.0%Through the use of CT scanning method to obtain cross-sectional images of different heights of Marshall specimens,and use MATLAB to perform image enhancement and image segmentation processing on different height images,the binary and ternary CT images of the asphalt mixture are realized,and the asphalt is separated.There are three substances contained in the mixture:mineral material,asphalt and voids;further research has been carried out on the voids,image gradation and the longest axis of the mineral material gap of the asphalt mixture.The voids of the specimens were compared and analyzed,and the void ratio of the asphalt mixture Marshall specimens was detected using the DIP method.It is concluded that the vertical distribution trend of the asphalt mixture voids is large at both ends and small in the middle.The average porosity of a single specimen is compared with the actual test piece.The difference between the average void ratio of a single test piece and the average value of the actual test piece is within 7%,and the void ratio can be obtained more accurately using DIP method.In the study of image gradation,it was found that more than 30 cross-sectional images can obtain a relatively stable recognition effect,and the best effect can be obtained when the coarse aggregate with a particle size of 4.75mm or more is recognized,with the highest accuracy.The fine aggregate in the range of 2.36-4.75mm needs simple correction.In the study of the longest axis of the mineral gap,it is concluded that the optimal blending ratio of basalt fiber length is 2:5:2(3mm:6mm:9mm).Finally,high-temperature rutting test,uniaxial penetration test,low-temperature trabecular bending test,dynamic modulus,IDEAL splitting test,SCB semicircular bending tensile test,water immersion Marshall test and freeze-thaw splitting test were carried out to study mixed-length basalt fiber Influence on high temperature stability,crack resistance and water stability.The results show that the asphalt mixture mixed with mixed-length basalt fiber can significantly improve its high-temperature performance,low-temperature performance and anti-cracking performance.When the basalt fiber length is 6mm and 9mm,the high-temperature performance is improved most obviously.When the basalt fiber length is 6mm The anti-cracking performance is most obviously improved when it is 3mm and 3mm.Therefore,increasing the content of basalt fiber with a length of 6mm can comprehensively improve the high temperature performance,low temperature performance and crack resistance of the asphalt mixture.When the mixing ratio of the mixed length fiber is 2:5:2,it has better high temperature performance,Low temperature performance and anti-cracking performance indicate that the asphalt mixture with basalt fiber blending ratio derived from the length of the main shaft of the mineral gap has better high-temperature performance,low-temperature performance and anti-cracking performance.The blending ratio of basalt fiber has certain guiding significance for the blending of fibers of different lengths.The research in this paper can provide technical reference for the design of mixed basalt fiber asphalt mixture,and has certain theoretical significance and practical application value.