Temperature Field Analysis of SRC-Column to SRC-Beam Joints Subjected to Simulated Fire including Cooling Phase

摘要

Three tests were performed on steel reinforced concrete (SRC) column to SRC beam joints subjected to fire scenarios including heating and cooling phases, and this paper reports the thermal part of the test results as well as the spalling observations. As these joints were designed to investigate the behaviour of a big joint zone including part of the beams and columns connected, temperatures in the junction and areas certain distance away from the junction were measured during both the heating and cooling phases. The three tests tested the influence of heating time on the temperature distributions at various sections of the specimen. A three-dimensional finite element analysis (FEA) model is developed to calculate the temperature field of the SRC column to SRC beam joints. The predicted temperatures show good comparison with the test results. Based on the finite element analysis, the differences of the temperature distributions in the joint zone and the non-joint zone are analyzed and its influence to the structural fire safety design is illustrated. One important conclusion from this study is the necessity to include cooling phase in structural safety design because it is in the cooling phase that the majority of the specimen materials reached their peak temperature.