| In recent years,Xuanwu Rock Fiber,as an efficient asphalt mixture enhanced body,is widely used in pavement engineering.The addition of basalt fiber to the asphalt mixture can significantly improve its performance.However,the current research is mostly aimed at the performance of quantitative or fixed-length basalt fiber modified asphalt mixture.The proportion of fiber length is associated with the characteristics of the illegal mixture skeleton.Studies have shown that in Xuanwu Rock Fiber modified asphalt mixture,the performance of hybrid length fiber is significantly better than a single length fiber.Therefore,if you want to further improve its performance,you need to carry out the optimization design of the mixed length of basalt fibergrade,and find the bone frame structure feature parameters in the asphalt mixed material.In this paper,the mixture design of AC-13,AC-20,and AC-25 graded asphalt mixture is conducted to determine the optimal asphalt stone ratio for AC-13,AC-20,and AC-25 grading:4.9%,4.4%,and 3.8%.When the basalt fiber content is 0.3%,the optimal asphalt stone ratio of the asphalt mixture is 5.1%,4.6%,and 4.0%,respectively.First of all,obtained the AC-13-level mixture Marshall testing through the macro test.It obtains multiple horizontal section images based on CT scanning technology.It uses MATLAB software to perform image processing.The collection of material and asphalt mortar is separated in digital information.Create the CLUMP coarse material template library through the outline shape of the real material,and based on the grade parameters obtained in the AC-13-based design experiment,establish the asphalt Mixed material two-dimensional discrete element model.For the level distribution of AC-13 asphalt mixture two-value image and discrete element model,the area of the gap between the skeleton gap and the gap rate of the material is extract and statistics.The technology can simply and accurately extract the asphalt mixture and observe the parameters,and the models they have obtained are higher.Therefore,the discrete element simulation technology can be used to accurately obtain the skeleton gap feature parameters of the asphalt mixture.Based on the gradation parameters obtained in the AC-20 and AC-25 mix ratio design experiments,a two-dimensional discrete element model of asphalt mixture was generated,and the skeleton gap characteristic parameters of AC-13,AC-20 and AC-25 graded asphalt mixtures were extracted.According to the distribution characteristics of basalt fibers in the skeleton gap of asphalt mixture,the matching ratio of mixed-length basalt fibers was designed according to the length and frequency distribution of the longest axis of skeleton gap,the shortest axis of skeleton gap and the average axis of skeleton gap.Finally,conduct high-temperature rut trials,single-axis penetration test,low-temperature beam bending test,water immersion Marshall test and freezing split test,study mixed length of basalt fiber-grade allocation of high temperature stability,low temperature crack resistance and water stability performance Impact.The results show that the mixed length of the basalt fiber-level distribution can significantly improve the high temperature and low temperature performance of the asphalt mixture.Among them,the ratio of 3mm,6mm,and 9mm of the AC-13 level with asphalt mixture is 2:5:2 Performance improvement is the best.Among the AC-20-level matching asphalt mixture,6mm,9mm,and 12mm of Xuanwu rock fiber matching ratio is 2:2:1 The percentage of 12mm,15mm Xuanwan fiber is the best performance at 2:3:1,and its best matching proportion matches the proportion of basalt fiber with the longest shaft design of the skeleton.Explain that the ectopic gap feature parameters can guide the grade and optimization design of the hybrid length of basalt fiber.This study can provide technical reference for the hybrid length fiber-grade optimization design of Xuanwu Rock Fiber Pragon hybrid,which has a certain theoretical significance and practical application value. |
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