Mechanical Property Evolution of Beams-Column Joints at Elevated Temperatures

Abstract:

In order to study the structural behavior of reinforced concrete beam-column joints and the changing rules of the constraints between them at elevated temperatures， thermal-load coupling tests on reinforced concrete frame beams were conducted. Based on the test， the VULCAN program is adopted to conduct the numerical analysis of the fire response of the frame beam subjected to high temperature alone， the beam-column subjected to high temperature at the same time， and the beam-column joint moment-rotation relationship at a constant load. The results show that the end restraint strength of reinforced concrete frame beams decreases with the increase of temperature. The peak value of the rotational angle at the beam-column joint has a certain delay compared to the peak value of the restraint moment.

Key words:beam-column joint;elevated temperature;rotational restraint;mechanical performance;fire experiments