The Experimental Study Of Hysteretic Behavior Of RC Board Benches Under Cyclic Tension And Compression Loading

The stairs are divided into stair slab and beam type stairs, Because of appearance and the construction is relatively simple, the stairs widely used in all kinds of buildings. The staircase has vertical transport function during normal use. In the coming earthquake, fire and other natural disasters, the stairs may also be the only important escape route. However, the 2008 Wenchuan earthquake damage survey found that, slab stairs appear a large number of destruction. In many buildings damage more serious than buildings itself, the staircase did not play its due function. The main reason is that previous seismic design did not consider the stairs to participate. But in fact, stair structure provides large lateral stiffness, will share the earthquake. In the reciprocating action of horizontal earthquake, boards of the ladder under reciprocating tension and pressure.In this paper, the study of the mechanical properties begin bench plate hysteretic behavior from research trials. By changing the bench plate width, the upper load, and whether with stairs, designed a six bench plate specimens experimental study. Analyzes the impact of the mechanical properties of the initial stiffness, ultimate deformation, ductility, energy dissipation capacity, stiffness degradation and failure modes of different parameters on the ultimate bearing capacity of the specimen. Main results obtained are as follows:(1) Reinforced concrete boards of the ladder under reciprocating tension and compression loading hysteretic behavior is relatively stable, load deformation hysteretic curve inverted S type. Compression properties including compressive strength, stiffness and energy dissipation, boards of the ladder are better than the tensile performance. The reason is that boards of the ladder when pressed, concrete and reinforced joint force; tension is reinforced under tension.(2) instead of the actual cast-in-situ stair plate by plate, will lead to their initial stiffness, yield load, ultimate bearing capacity, ductility and energy dissipation capacity than the actual situation to the small.(3) The vertical load of the reinforced concrete step board could reduce the tension compression bearing capacity, stiffness and ductility and other mechanical properties, and the degree of decrease related to vertical load.(4) Along with the step board width increases, the compressive stiffness (initial stiffness, yield stiffness, post yield stiffness) is greater, the higher ultimate strength, ductility and better; tensile loading quantity is proportional to the force and the internal reinforcement.(5) Before the destruction, energy dissipation capacity of bench plate is related to the failure modes. Step board shear failure energy dissipation capacity to significantly weaker than the bending damage energy dissipation.In addition, based on the experimental study, the restoring force model is established for the boards of the ladder pulling force and displacement relationship of compressive loads in reciprocating. They can provide a basis for structural analysis.