| Fiber materials have been used in road engineering for more than 60 years.The three-dimensional lattice structure formed by fibers in asphalt effectively restricts the deformation and flow of asphalt after high temperature,and at the same time,it can stretch the asphalt around itself,consume some plastic deformation,and exert "stretching prestress" on asphalt to improve the elasticity of asphalt,so that it can bear more loads without damage,and reduce the possibility of reflective cracks on asphalt pavement.However,with the rapid development of national green energy materials,the scientific research on the preparation and application of crop by-products has been focused by scholars,and there are more and more related research and experimental projects on corn stalk fiber as asphalt modification materials.Through summarizing and analyzing the existing research,it is considered that the preparation process of corn stalk fiber can be changed by copying lignin fiber,and according to the biological characteristics of corn stalk,the heat resistance of corn stalk fiber can be fully exerted to prepare road corn stalk fiber with more obvious fiber characteristics.Corn stalk fiber was prepared from corn stalk bark after mechanical crushing and water absorption,and its fiber strength and rough surface were maintained.The comprehensive heat resistance test of the fiber proved that the heat resistance of corn stalk fiber could meet the requirements of road engineering temperature and heating time without flame retardant.The color change of corn stalk fiber during heating is related to the difference of high and low temperature properties of modified asphalt.It is found that high temperature can destroy the structure of corn stalk fiber,cause cellulose to volatilize,seriously reduce the structural strength of fiber,and gradually weaken the modification effects such as reinforcement.Comparing the high-temperature and low-temperature test results of lignin fiber modified asphalt,it is found that the high-temperature performance of corn stalk fiber modified asphalt is significantly better than that of lignin fiber modified asphalt,and its low-temperature performance is similar to that of lignin fiber.The unique fiber strength of corn stalk fiber plays a prominent role in improving the high-temperature rheology of asphalt,and at the same time,it increases the elasticity of asphalt,so that the modified asphalt mixed with corn stalk fiber can withstand greater load impact without deformation,and more plastic deformation can be transformed into recoverable elastic deformation,which significantly improves the service life of asphalt. |
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