Experimental Study on Damage of Concrete Subjected to RepeatedLoading after Exposure to Elevated Temperatures

摘要

Current concepts of structural analysis are aiming to new buildings. They are not applicable toexisting buildings for not considering the degradation of materials during service. So the research ofmaterial cumulative damage is vital to assessment, appraisal and rehabilitation of existing buildings.The objective of this paper is to understand damage evolution and cumulative damage of concreteunder external influences such as elevated temperature and repeated loading. Four groups of panelspecimens have been tested, focusing on degradation of concrete material subjected to hightemperature and repeated loading with different temperatures and stress ratios. By analyzing thestress-strain curves acquired in the test, relationships between biaxial concrete strength and elevatedtemperature or stress ratio have been obtained. Furthermore, the damage evolution law for concretewith initial damage is discussed. The results of tests can provide a basic background to analyze thedamage of existing shear-wall buildings.