Experimental Study On Seismic Behavior And Damage Model Of RAC Frame Interior-joints Which Contain Hybrid Fiber

Preparation of concrete requires a lot of natural sand as its aggregate, and from exploration to production and then to demolish the building, each link will produce a lot of pollution on the environment. The preparation of recycled concrete while reducing the demand for natural gravel resources, on the other hand it can turn building waste into treasure, and it is good for the sustainable development and ecological environments. However, recycled concrete aggregates are waste concrete block through special processing before it is applied, and this leads to the more harmful internal defects in recycled concrete. In order to improve the lack of recycled concrete,and open its market, the theory of enhanced performance recycled concrete becomes necessary.First, we put different dosage of silica fume, steel fiber and polypropylene fiber into recycled concrete to enhance its performance, and prepare 25 groups 80 concrete blocks for in-depth studying of the mechanical properties of enhanced performance recycled concrete. The test results show that silica fume and hybrid fiber can improve the flexural, tensile, compressive strength of recycled concrete.According to materials testing, produce three RAC Frame Interior-joints with the design ideas of "strong column strong beam and weak nodes", and the test variable is only the hybrid fiber content of the specimen, remaining the other conditions. By the low cyclic loading test, Study the failure process, destruction phenomena, hysteresis curve, ductility and energy dissipation capacity of each node specimens. By analyzing the test data, discusses how to enhance the seismic performance of the specimens by changing the hybrid fiber content.Based on experimental phenomena and data of specimens, by analyzing the common single parameter and two-parameter model for earthquake damage, We study which model is more suitable for assessing the damage of the three specimens. Based on Park-ang damage model, introduced two coefficients for displacement term and energy term, and improved model by introducing a new parameter named fiber term.Proposed amendments to the earthquake damage model.This model can provide a reference for the damage assessment of the RAC frame interior-joints.