Study On Stirring And Dispersing Motion Field Of PVA Fiber Bundle And Evaluation Method Of Dispersion Uniformity

PVA fiber has many advantages such as high strength,high modulus,abrasion resistance,acid and alkali resistance,and good weather resistance.It can be well combined with cement-based materials and can improve the road performance of cement stabilized macadam base.However,due to the characteristics of extremely small diameter,factory-made bundles,and strong hydrophilicity,PVA fibers are difficult to uniformly disperse in cement stabilized macadam.In order to make the PVA fiber fully exert its excellent performance,it is necessary to disperse the PVA fiber into a monofilament-like network structure before it enters the cement stabilized crushed stone mixing station.Based on Science and Technology Project of Yunnan Provincial Communications Department,a dispersing method of mixing and stirring PVA fibers with fly ash is proposed,and a PVA fiber stirring and dispersing device is designed based on this.This paper first describes the basic structure and working mechanism of the device,and combines the basic theory of the agitating and dispersing motion field to establish a motion field model of the agitating tank of the PVA fiber agitating and dispersing device.Based on this,the kinematic characteristics of the mixing tank sports field were analyzed and analyzed from the aspects of the rotation speed of the stirring shaft and the mass ratio of PVA fiber to fly ash.The optimal speed and mass ratio of PVA fiber dispersion were obtained.Then,based on the PVA fiber stirring and dispersing device,based on the stirring shaft speed,the mass ratio of PVA fiber to fly ash,and the stirring and dispersing time,the dispersion uniformity of PVA fiber was experimentally studied.The combination of image processing technology and The principle of image texture feature is used to extract the texture features of the test samples,and the two second-angle moments and the entropy values in the gray level co-occurrence matrix are used to evaluate the dispersion uniformity of the PVA fibers.PVA fiber dispersion uniformity.Finally,by comparing the results of the sports field simulation with the experimental research,the reliability of the device's sports field simulation was verified,and the optimal working parameters of the PVA fiber dispersion were obtained: the mass ratio of PVA fiber to fly ash is 1:45,and the agitation The shaft speed is 700 r / min,and the stirring time is 3min.In this paper,the method of combining the simulation and experimental research of the dispersion and dispersion process is used to complete the analysis of the motion characteristics of the PVA fiber bundle agitation and dispersion motion field.A method for evaluating the uniformity of the dispersion of PVA fibers using digital image processing technology and image texture features is proposed.The optimal working parameters of the PVA fiber bundle agitating and dispersing device were determined,and the dispersion efficiency and quality of the PVA fiber bundle were improved.In actual engineering,it has certain reference value for improving the dispersibility of PVA fiber bundle and improving the road performance of cement stabilized macadam base.