| Tunnel fire has the character of temperature rising up rapidly and highly, which may severely damage safety of people's lives and properties. For designing fire-resistant performance of tunnel lining, deteriorations of materials due to high temperature are needed to consider on one hand, while thermal stress due to temperature rising-up acutely should also be considered on the other hand. Safety of tunnel is also decreased by severe deformation and cracking of lining structure. For this reason, aiming at the behaviours of Fiber Reinforced High Performance Concrete (FRHPC) pipes under high temperature impact, based on the project of National Nature Science Foundation, Investigation on Bearing Capacity of Fiber Reinforced Concrete/Shotcrete under the Repeated High Temperature (No. 50278013), the following researches are presented in this thesis:1. Test on workability of FRHPC are carried out. High Performance Concrete (HPC) with high workability is developed. The influences of steel fiber, PP fiber and hybrid fiber with different type and content on the Slump-Flow of HPC before and after vibrating are analyzed. PP fiber and hybrid fiber have remarkable effects on decreasing the workability of HPC, but with slightly vibrating the effects can be mitigated. Casting pipe successfully is ensured.2. Test on compressive strength and elastic modulus of FRHPC before and after high temperature are carried out. PP fiber has clear effect on the compressive strength after high temperature of 400℃. The influence of high temperature on elastic modulus is greater than on compressive strength.3. Based on summarizing thermal properties of Normal Concrete (NC), test on thermal expansion property of FRHPC under high temperature are carried out. Hybrid fiber can clearly reduce the thermal expansion of HPC, which provides support for engineering practice of using hybrid fiber to decrease thermal stress of concrete structure under high temperature impact. The formulae of free thermal strain and the average thermal expansion coefficients of FRHPCs under high temperature are presented, which can be calculation parameters when analyzing high temperature behaviour of relevant structure.4. Based on the character of temperature rising-up rapidly and highly in tunnel fire, a fire-simulated high temperature test system, which is suit for researching pipe's performance of resisting high temperature impact, is developed. Pipe' features and changing laws of temperature and deformation under high temperature impact are investigated. Based on FE solution of thermal stress, the relationship between temperature, deformation and stress is analyzed. Simplified formula for calculating radial displacement of pipe's outer-side layer before cracking is presented.5. The influence of different fibers on pipe's deformation under high temperature and cracking manner after high temperature is analyzed. Hybrid fiber restricted pipe's deformation under high temperature, reduced crack width after high temperature, also made pipe's crack distribution "more, thin and dense" after high temperature, so can improve pipe' s performance of resisting high temperature impact as a result.6. Analyzing temperature field inside concrete member under high temperature/fire is the precondition for investigating high-temperature mechanical bahaviour of members and structures. Based on test data, using ANSYS, FE analysis on transient temperature field of pipe is carried out, and the effects of choosing different thermal properties and convection coefficients on the solution are discussed at the same time.7. Based on temperature field analysis, FE analysis on pipe's deformation and thermal stress before cracking under high temperature impact is carried out. Distribution and law of thermal stress changing with temperature is summarized, and stress state of pipe shell when cracking is analyzed.
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