500 Mpa Grade Low Reversed Cyclic Loading Tests Of Reinforced Concrete Frame Structure Research

With the constant attention of anti-seismic problems and improvement of thenational criterion, the requirement of the seismic resistance capacity of the buildingshas become tougher and tougher. Many original buildings and material can not meetthe requirements of the seismic resistance.HRB500grade high strength bars havebeen added and will be spread by newly revised Codes of concrete structuredesign(GB50010-2010) which published in2011, but our country researched onreinforced concrete frame structure which with HRB500seismic behavior testis stillin the initial stage. Which causes inconvenience in revising the item on high strengthsteel bars of the code GB50010as well as in application of high strength bars inprojects. Tests were conducted on four frames under low-cycle reversed loading andone frame under thrust loading to study seismic behavior on concrete framesreinforced with HRB500steel bars.1. The main contents are listed as follows:(1) Describes the development of domestic and international overview of steelreinforced concrete structures, earthquake damage and performance problems in thesteel, high strength reinforcement in reinforced concrete structures in seismicproblems and advantages.(2) Describes the trial design, and tests were conducted on four frames underlow-cycle reversed loading and one frame under thrust loading to study seismicbehavior on concrete frames reinforced with HRB500steel bars, the phenomenonobserved and recorded the test, get test data of each specimen such as hystereticcurve.(3) The destruction of the specimen shape, hysteresis curve, the skeleton curve,ductility, steel strain, stiffness degradation and energy consumption were analyzed.This configuration also made of reinforced concrete frame structure HRB500skeletoncurve restoring force model, derived a theoretical framework for solving thecharacteristic parameters of the empirical formula of the curve.(4) Finite element analysis software for this experimental configuration HRB500reinforced concrete frame structure for a pushover analysis, and test results and theresults were compared.2. The main conclusions are listed as follows: Studies based on tests indicate that most of the longitudinal rebars reached theiryield strength.when the specimens were under peak loading;different sectiondimension framework, corresponding to different seismic performance,all specimensreached their yield strength after the specimens were seriously damaged.Thehysteretic curves are shuttle-shaped,and some of them show slight pinching．Allspecimens exhibited high strength and good displacement ductility,and clearindication on the energy dissipation capability is shown. Seismic performanceevaluation test framework that can meet the requirements of8degree earthquake.