Study On Shear Behavior Of Reinforced Concrete Columns With Rectangular Cross Section In Fires

Reinforced concrete structure is widely used in architecture, the number of which suffering a fire is quite large. Reinforced concrete is the main load-carrying member of the structure, and the mechanical property of it will go down under high temperature. Once shear failure occurs, it may lead to building collapse. Domestic and international studies on the shear capacity of reinforced concrete under high temperature have achieved something, but the studies usually select central columns as the model, ignoring the study of side columns and corner columns. In this paper, reinforced concrete rectangular section corner columns are selected as the study model, use ABAQUS software to analyse the temperature fields distribuion of it and compare the shear capacity under high temperature and normal temperature. With the software programming of Visual C++6.0, something as follows has been done to make it convenient to calculate the shear of reinforced concrete rectangular section corner columns and judge whether they are in shear failure:1.The shear capacity study of reinforced concrete rectangular section columns under normal temperature. Analyse the shear of reinforced concrete rectangular section columns with the combined action the horizontal load and longitudinal load by using ABAQUS software, and study the relative influencing factors.Studies show that slenderness ratio and axial compression ratio are the main factors that influence the shear capacity of reinforced concrete rectangular section columns at normal temperature. The increase of concrete strength, longitudinal reinforcement and stirrup reincorcement ratio can improve the shear capacity of reinforced concrete rectangular section columns in a certain range, while the thickness of protective layers is not the main factor.2.The temperature fields analyse of reinforced concrete rectangular section corner columns. Analyse the temperature fields of reinforced concrete corner rectangular section columns with two sides in fire by using ABAQUS software, and study the relative influencing factors.Studies show that the size of the sections and fired-time are the main factors that influence the distribution of temperature field, while different temperature curves influence less.3.The shear capacity study of reinforced concrete rectangular section columns under high temperature. Analyse shear capacity of reinforced concrete corner rectangular section columns with two sides in fire by using ABAQUS software, study the relative influencing factors, and compare the shear capacity with that under normal temperature. Studies show that the thickness of protective layers and the size of sections are the main factors the influence shear capacity at high temperature; the increase in ratio of reinforcement can strengthen the shear capacity of reinforced concrete rectangular section columns, while over-high ratio of reinforcement may cause brittle failure; yet the increase of strength grading of concrete cannont improve the shear capacity of reinforced concrete rectangular section columns.4.Use C++to programme for the shear capacity of reinforced concrete columns under normal temperature and high temperature, and give some ralative examples. Probe whether reinforced concrete columns are in shear failure under different influencing factors.To some extent, this paper will be a reference for the further study of reinforced concrete corner columns shear capacity and the setting of reinforced concrete rectangular section cormer columns’shear specification under high temperature.