Performance Of Reinforced Concrete Column Under The Post-earthquake Fires

Secondary disaster has now become an important issue of human to face,and fires caused by earthquakes is one of more common phenomenon.Post-earthquake fire(PEF)presents a high risk to buildings that have been partially damaged in a prior earthquake,since the earthquake induced damages make the structure more vulnerable to fire effects than the undamaged one,that means a rapid collapse of the buildings and the consequences will be unimaginable.However,it is not been fully considered this point in the design of building structures.Since the earthquake and fire damage to building structures are more complex,different levels of earthquakes and fires can cause varying degrees of different situations.If large numbers of experiments be used,that following the cost and time would be too much.So it is very efficient and necessary to analysis and study of the extent of damage to the reinforced concrete structures and the fire resistance performance by a large general-purpose finite element software.Firstly,this paper lists a large number of domestic and foreign cases which cause a fire caused by the earthquake especially serious casualties.It's fully showing this secondary disasters of the fire after the earthquake happened in a high incidence rate.That should be get enough attention.And this paper reviewed current research results relevant tests to determine the contents.Secondly?it collated and analyzed the destruction of reinforced concrete columns that may occur in the earthquake.There are mainly about cracks in the protective layer peeling,mechanical performance,and last may eventually lead to the destruction of the column.Bending failure,shear failure and cyclic shear:reinforced concrete columns will mainly occur in the following manner destroy.Also reference parameters described in the relevant column of earthquake damaged proposed in the literature,and select damage factor 0.8 for the data of this study.Then?it summarized and compared the variation on thermal parameters and high temperature mechanical properties of reinforced concrete at home and abroad.Respectively,it summarizes the material thermal performance from the thermal conductivity,specific heat capacity,thermal expansion coefficient and mass density and the high temperature mechanical properties from the elastic modulus,compressive and tensile strength,stress-Summary material strain relationships,high-temperature creep.Finally,using ABAQUS finite element software to simulate the situation of four reinforced concrete columns damaged by the fire,and to select the appropriate parameters of temperature field of reinforced concrete columns.In this paper,the results of previous studies using the standard reference temperature curve,simulated earthquake damaged pillar state when the force at high temperatures.Observing the distribution of temperature field of reinforced concrete columns multiple-section and discusses the degradation of material properties under conditions of injury and anti-impact fire behavior of reinforced concrete columns.Arrived at a different node damage concrete column temperature,the temperature field in different sections nephogram.The results showed that:in damaged conditions,temperature and cross-sectional dimensions have great influence on the bearing capacity.And analysis of results that it's easy to happen brittle shear failure at the ends of the damaged column with peeling off the protective layer.