Research On Pavement Performance And Pavement Structure Of Polypropylene Fiber Reinforced High Performance Concrete

Polypropylene fiber reinforced high performance concrete is a new kind of composite material which has been concerned by the engineering field in recent years.It has the excellent characteristics of crack resistance and fatigue resistance.Through consulting a large amount of literature,at the same time,the problems and the research results encountered in the research of fiber reinforced concrete at home and abroad are analyzed,combined with the climatic conditions in Chengde and the use of existing concrete pavement,the design optimization and its road performance of high performance concrete with high performance of polypropylene fiber are systematically studied.The main research contents are as follows:(1)In the study,combined with the specification and the mix proportion design experience,the response surface method with fly ash,sand rate and water reducer as the independent variables and 28 d flexural strength as the response variable was determined.The influencing factors of 28 d flexural strength,the regularity and the optimum mix ratio of high performance concrete were determined and analyzed.At the same time,the optimum dosage of slag was also determined.(2)On the basis of the optimum concrete mix ratio determined by the response surface,mixed with different content of polypropylene fiber,and its mechanical properties such as compressive strength,flexural strength and impact resistance were compared and analyzed,the influence of polypropylene fiber on the mechanical properties of high performance concrete was studied.(3)Durability of concrete is related to the life of the primary performance of concrete pavement,therefore,this paper continues to test the shrinkage performance,chloride ion impermeability and fatigue performance of high performance concrete with different content of polypropylene fiber,The effect of polypropylene fiber on the durability of high performance concrete was analyzed,and summarize the change law of the durability of the fiber concrete.(4)According to the mechanical variation law of fiber reinforced concrete,using KENPAVE pavement structure analysis and design software analyzes the coupling stress of concrete pavement,the axle load under the action of tensile stress in the bottom of the temperature stress and temperature differences.The coupling stress of the concrete pavement structure,the tensile stress at the bottom of the pavement under the axial load and the temperature stress under the temperature difference are analyzed by KENPAVE pavement structure analysis and design software.At the same time,the variation of the tensile stress and the temperature stress of the concrete pavement structure under different axial load and different temperature gradient was analyzed with the surface layer thickness of 30 cm.