Study on the performance of ground melon vine straw fiber modified asphalt

Abstract

In order to reduce the waste of resources and the pollution of ecological environment caused by the large amount of waste crop straw accumulation or incineration, and to realize the high-value utilization of waste straw resources, this paper adopts the mechanical crushing method, acid and alkali solution treatment method to prepare the groundnut seedling straw fibers, and compares and analyzes the micro-morphology and chemical composition and thermal stability of the groundnut seedling straw fibers prepared by the physical method, the NaOH solution method, and the HCL solution method, through the scanning electron microscope, infrared spectroscope and the thermogravimetric analysis test; secondly, the optimal blending range of the groundnut seedling straw fibers is preferred. Secondly, the optimal dosage range of ground melon vine straw fiber was selected, the preparation process of ground melon vine straw fiber modified asphalt was proposed, five different dosages of ground melon vine straw fiber modified asphalt were prepared, and the basic properties, viscosity and temperature characteristics, and storage stability of ground melon vine straw fiber modified asphalt were analyzed; and then, a dynamic shear rheometer was used. Dynamic Shear Rheometer and Bending Beam Rheometer tests were used to study the high and low temperature rheological properties and resistance to permanent deformation of ground melon vine straw fiber modified asphalt, and the optimal dosage of groundnut seedling straw fibers was determined; finally, through Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy tests, the chemical components of ground melon vine straw fiber modified asphalt were clarified, and the chemical components of ground melon vine straw fiber modified asphalt were revealed to be the most important. The toughening mechanism of ground melon vine straw fiber modified asphalt was revealed. The results showed that the chemical alkali treatment method was the best preparation process for groundnut straw fiber, and the process flow was to use NaOH solution with a mass fraction of 3 % to treat the ground melon vine straw fiber for 50 min at a temperature of 60 °C; compared with the matrix asphalt, the needle penetration and elongation of the ground melon vine straw fiber modified asphalt decreased with the increase of the blending amount, and the softening point, the equivalent softening point, and the temperature sensitivity of the asphalt increased. Sensitivity enhancement, softening point difference in line with the specification requirements, but the ductility in the low dosage improved; with the increase in the dosage of ground melon vine straw fiber, ground melon vine straw fiber modified asphalt rutting factor, creep modulus, 0.4 %–1 % dosage of the creep rate and creep recovery rate increased, while 1.3 %–1.6 % dosage of the creep rate and the amount of unrecoverable creep flexibility decreased The results show that 0.4 %–1.6 % dosage of melaleuca alternifolia straw fiber modified asphalt high temperature performance and resistance to permanent deformation performance, and 0.4 %–1 % dosage of melaleuca alternifolia straw fiber low temperature performance has also been improved, the overall consideration, to determine the optimal dosage of melaleuca alternifolia straw fiber 1 %; melaleuca alternifolia straw fibers (NaOH) and the asphalt combined with the production of new functional groups, and melaleuca alternifolia straw fibers with each other. Lap cross to form a fiber skeleton grid structure, can play a role in the entire material to transfer stress and crack resistance, asphalt to play the role of enhanced toughening effect.