Study On Road Performance Of Biomass Fiber Asphalt Mixture

At this stage,asphalt pavement is the main form of road in China,with the increasing amount of vehicles in recent years,asphalt pavement disease frequently,in the asphalt mixture mixed with fiber operation is simple and can improve its road performance,so the method is widely used.Biomass fiber refers to the fiber with biological texture,such as lignin fiber,straw fiber,bamboo fiber and bagasse fiber,etc.Bamboo is a typical fast-growing plant with high regenerative capacity,and the bamboo fiber made from bamboo as the raw material has good mechanical strength and resilience.On the other hand,as a large agricultural country,China has a large amount of agricultural straw output every year,the burning of waste straw will produce greenhouse gases,causing great harm to the environment and human body.If the straw can be made into straw fiber and used in the road,in reducing environmental pollution at the same time can also meet the needs of agricultural waste material reuse.In order to improve the performance of asphalt pavement and expand the utilization of bamboo and corn straw,the road performance of asphalt mastic and its mixture mixed with bamboo fiber and corn straw fiber is studied.The main research contents are as follows:Firstly,in this paper,a set of process flow applicable to the preparation of corn stover fiber and bamboo fiber was designed independently,and two different morphologies of bamboo fiber and corn stover fiber,namely long bamboo fiber(BFL),short bamboo fiber(BFS),long corn stover fiber(CFL),and short corn stover fiber(CFS),were obtained by controlling the parameter process during fabrication.And the two long biofibers were modified with a homemade phenolic resin-copolymer modifier to obtain modified long bamboo fiber(M-BFL)and modified long corn straw fiber(M-CFL).Then the oil absorption performance,moisture absorption performance,thermal stability and other basic technical indexes of bamboo fiber and corn straw fiber were tested,and lignin fiber was used as the comparison group;the similarities and differences of different types of biofibers at the microscopic level were compared by SEM images;the FTIR test was used to evaluate the modification effect of biofibers.Among them,lignin fiber(LF)had the best oil absorption,corn stover fiber(CF)had the greatest moisture absorption,and bamboo fiber(BF)had the best high temperature stability.The infrared spectral images showed the formation of new functional groups,which proved the successful modification of biomass fibers,while the modified biomass fibers showed reduced oil absorption,improved moisture absorption resistance and high temperature resistance,and showed a resin film attached to their surface under microscopic view.Next,the effects of the type,morphology and modification of biomass fibers on the shear resistance,viscoelastic properties,high temperature performance and low temperature rheological properties of asphalt mastic were analyzed.The results showed that bamboo fibers(BF)performed best in high temperature performance,shear resistance and viscoelastic properties with the same dose,with BFL outperforming BFS;CFS showed flocculent shape and outperformed CFL in terms of viscoelastic properties and high temperature performance,while CFL showed needle shape and outperformed CFS in terms of shear resistance.The performance of the two modified biomass fibers,M-BFL and M-CFL,was slightly improved in terms of shear and high temperature resistance.In addition,the incorporation of biomass fibers weakened the low temperature rheological properties of the asphalt mastic.Finally,the high-temperature stability,water stability,low-temperature crack resistance and fatigue resistance of the biofiber asphalt mixes were evaluated,and the microscopic morphology at the fracture of the fiber asphalt mixes was observed.The results showed that the incorporation of biomass fibers improved the road properties of asphalt mixes;bamboo fibers(BF)had the best effect on the road properties of asphalt mixes,with BFL being better than BFS;flocculated corn stover fiber CFS was better than needle corn stover fiber CFL in terms of high temperature and fatigue resistance,while CFL performed better than CFS in terms of water stability and low temperature crack resistance;and CFL was better than CFS in terms of water stability and low temperature crack resistance.are better than CFS;The two modified biomass fibers,M-CFL and M-BFL,showed improved performance in terms of low temperature cracking and fatigue resistance.The microscopic images showed that the damage of biomass fibers was tensile damage,and the incorporation of fibers effectively prevented the development of cracks in the mix,which could bear and transfer the load when the asphalt mix was stressed.