Study On Properties And Application Of Short-cut Fiber Asphalt Mixture

In recent years,asphalt concrete pavement has become a widely used form of highgrade highways in China.However,with the increasingly heavy traffic volume,rutting deformation,temperature shrinkage cracks,reflection cracks,and water damage,such as pit looseness,have appeared on the asphalt pavement of China's expressways,which have seriously affected the road performance of asphalt pavements and made service life of asphalt concrete pavements greatly reduced,far beyond its design lifetime.At present,asphalt pavements in China are facing issues such as insufficient road durability,long maintenance cycles,high maintenance costs,and imperfect road performance.Therefore,how to prevent and avoid early damage of the asphalt concrete pavement and increase the service life of the asphalt pavement to improve the performance of the asphalt pavement has become an urgent problem to be solved.Relies on the Ministry of Science and Technology's national key research and development project ? Key Technologies for the Preparation and Engineering Application of High-Performance Fibers and Geotextiles for Construction-Road Construction Technology and Engineering Applications of Geotechnical Building Reinforcing Materials?,this article mainly carried out the following three aspects of research:Tests were conducted on various physical performance of chopped fibers,as well as the oil absorption properties,thermal stability of chopped fibers,and the dispersion of fibers in the asphalt mixture.The balanced design method of asphalt mixture based on skeleton-inserted principle was adopted.Marshall test was used to test the volume index of chopped fiber asphalt mixture and the best ratio of oil and asphalt.The effects of different short-cut fibers on the various volumetric parameters of the asphalt mixture,as well as the analysis of its impact mechanism,were studied.Through the rutting test,trabecular bending test,Marshall residual stability test and freeze-thaw splitting test,four-point bending trabecular fatigue test,indirect tensile test,the high-temperature stability,low-temperature crack resistance of the chopped fiber asphalt mixture water stability,fatigue performance and mechanical property were respectively investigated in a comprehensive systematic road performance indoor test.Through the indoor test,the performance of the chopped fiber asphalt mixture was evaluated.PVA fiber and PET fiber were selected to verify the technical advantages of strengthening and toughening the fiber asphalt concrete under heavy-load lowtemperature conditions.The author's team paved chopped fiber asphalt concrete test road in the reconstruction and expansion project of Jinghui Road in G247,Gansu Province.The results show that the volumetric parameters of the chopped fiber asphalt mixture and the optimal ratio of oil to stone are obtained through the balanced design of the chopped fiber asphalt mixture based on the principle of skeleton-inserted type extrusion.The high temperature stability and low temperature of the chopped fiber mixture are also obtained.The crack resistance,fatigue resistance and mechanical property have been improved to a certain extent,and the improvement effect is obvious;while for water stability,the residual stability of PVA fiber asphalt mixture and PET fiber asphalt mixture has been improved,polyester fiber asphalt mixture,The ratio of freeze-thaw splitting strength of PAN fiber asphalt mixture,lignin fiber asphalt mixture,and PET fiber was improved.Through the test of paving and road performance of PVA fiber asphalt concrete test road,it shows that chopped fiber has good economic and social benefits in road engineering,and has broad application prospects in the future.