Asphalt Adsorption Mechanism Of Corn Stalk Fiber And Road Performance Research Of Corn Stalk Fiber SMA

As a large agricultural country,China also produces a large number of stalk crops while producing a large amount of food,and the burning and accumulation of stalk will cause harm to the environment.If corn stalks are made into fibers and applied to the asphalt pavement,this will not only alleviate the environmental pollution of stalk crops,but also play a role in turning waste into treasure and saving limited resources.It has greater environmental and economic value.However,how to make corn stalks into fiber materials that meet the requirements of asphalt pavement is still in the research stage to varying degrees.At the same time,there is no corresponding technical standard for corn stalk fiber used in asphalt roads.To this end,this article will propose a preparation technology that is compatible with the application of corn stalk fiber on asphalt pavement,and give the technical evaluation index of corn stalk fiber.On this basis,the performance of corn stalk fiber asphalt and SMA mixture will be studied.This paper analyzes the composition and structure of corn stalks,and selects corn stalk skins as the raw materials for making fibers.The raw material of corn stalk skin is obtained through the separation of skin and core,and the physical and chemical treatment of corn stalk skin was carried out.The preparation technology of corn stalk fiber was determined based on the results of the experiment of fiber oil absorption test.On this basis,the properties of corn stalk fibers are tested,combining with the technical requirements of flocculent wood fibers in my country transportation industry standard asphalt pavement fibers(JT/T 533—2020)to evaluate the performance of corn stalk fibers.The evaluation index of corn stalk fiber for asphalt roads is proposed.The BET test method is used to analyze the pore structure of corn stalk fibers.Based on the experiment of corn stalk fiber adsorbing asphaltenes,the ability of corn stalk fiber to adsorb asphaltenes at different dosages and the adsorption effect of unit corn stalk fiber on asphaltenes in different types of asphalt are analyzed.Combined with the adsorption kinetics and adsorption isotherm model,the dynamic three-stage adsorption mechanism of corn stalk fiber adsorbing asphaltene is revealed.Then,molecular dynamics simulation method is used to establish four different component ratios of asphalt molecular models and corn stalk fiber molecular models.After that,it sets the molecular force field and calculates the parameters,and builds the interface molecular dynamics model.According to the simulation results,the regularity of the adsorption of different components of asphalt by the corn stalk fiber is analyzed.The study shows that the saturation and aromatic components have larger diffusion coefficients.The high,low temperature performances of corn stalk fiber asphalt are studied,and the effects of corn stalk fiber on the temperature sensitivity,high temperature and low temperature properties of asphalt at different dosages are studied.The test results show that the corn stalk fiber can increase the viscosity of asphalt,improve the temperature sensitivity of asphalt and improve the high-temperature properties of asphalt.Moreover,the improvement effect of lignin fiber and basalt fiber on the performance of asphalt can be achieved by increasing the content of corn stalk fiber.Based on Han curve analysis,corn stalk fiber has good compatibility with asphalt.When a small amount of corn stalk fiber is mixed into the asphalt,the fiber will play a part of toughening effect in the asphalt.However,with the increase of the fiber content,the adsorption and stabilization of the fiber in asphalt will become more prominent.According to the physicochemical and mechanical properties of corn stalk fiber and basalt fiber,research on the regulation and improvement of the road performance of SMA mixture will be carried out.Based on the fiber asphalt test results,different corn stalk fiber contents are selected for SMA-13 mixture ratio design and high temperature performance,low temperature performance,water stability,fatigue performance and dynamic modulus performance test of mixtures are studied.Combining with the road performance of lignin fiber and basalt fiber asphalt mixtures,it reveals the improvement law and action mechanism of corn stalk fiber on the road performance of SMA mixture.Then it will design the adsorption(corn stalk fiber)+ reinforcement(basalt fiber)mixed fibers,and carry out the SMA-13 mixture ratio design and the high temperature performance,low temperature performance,water stability and fatigue performance test research of mixtures,and clarify the effect of the mixed fiber on the control principle of SMA mixture performance.Finally,through the comparative analysis of the road performance and economics of the SMA mixture,it is recommended that a reasonable amount of corn stalk fiber and mixed fiber will be used to adjust and improve the performance of the SMA mixture.This paper paves the corn stalk fiber and basalt fiber SMA-13 mixture indoor test road,carries out the production mix ratio design,and summarizes the corn stalk fiber and basalt fiber asphalt mixture road construction technology.Then,based on the full scale accelerated loading test,the rutting depth of the corn stalk fiber and basalt fiber SMA-13 surface layer structure and the lignin fiber SMA-13 surface layer structure are analyzed.The research results show that the corn stalk fiber and basalt fiber SMA-13 surface layer structure has a longer service life.This provides case analysis and technical support for the application and promotion of corn stalk fiber asphalt mixture.