Experiment Mechanical Behaviors Research On Post High Temperature Reinforced Recycled Aggregate Concrete Beam

Combined the advantages of the reinforced concrete structures and recycled aggregate concrete, Reinforced recycled aggregate is proved to be energy saving, environmental friendly and sustainable has a board application prospect. However, studies regarding strength and rigidity degradation of mechanical behaviors of post high temperature reinforced recycled aggregate concrete beam for are insufficient and requires relevant research.The mechanical behaviors of post high temperature reinforced recycled aggregate concrete beam are researched in this thesis supported by experimental researches and numerical simulations.Firstly,34 reinforced recycled aggregate concrete beam specimens are created,26 of which are post high temperature ones and the rest 8 are regular specimens place in room temperature just for comparison purpose. According to ignition loss results of 26 specimens from high temperature test, a method of estimating highest temperature that members had been suffered is proposed. The temperature fields of specimens are simulated in high temperature by abaqus software, and influence factors of temperature field are analyzed.Next, based on the damage experiments on normal sections and inclined sections of reinforced recycled aggregate concrete beam after tests in high temperature, the damage process and failure mode of specimens are observed, and the load-deflection curves are obtained. The effects of replacement ratio of recycled aggregate concrete, high temperature and concrete strength of specimens are investigated, and the bearing capacity, rigidity, damage, ductility and energy dissipation are analyzed.The results indicate that the bearing capacity, rigidity, ductility and energy dissipation of specimens after high temperature tests are decreased. The damage of flexural member increases with the higher of replacement ratio. High temperature and concrete strength have a great influence on shear failure of members. Higher temperature and lower concrete strength decreased the bearing capacity, ductility as well as energy dissipation of shear members.Finally, based on the results from tests and numerical simulation, the methods to calculate the bearing capacity of normal sections and inclined sections of post high temperature reinforced recycled aggregate concrete beam are proposed. The calculation results are in good agreement with the experimental results.