Experimental research on fire behavior of RC columns strengthened with angle steel
Zhou Liren1,2 Mao Xiaoyong1,2 Zhang Xiang1,2
1. Suzhou University of Science and Technology, Suzhou 215011, China
2. Jiangsu Key Laboratory of Structural Engineering, Suzhou University of Science and Technology, Suzhou 215011, China
Abstract：As a widely used practice in engineering, strengthening with angle steels can effectively improve the bearing capacity of concrete column but with a little increasing of section area. Angle steels located outside the column are easy to be exposed to fire due to the exfoliation of the mortar proof, so the fire resistance of the RC column strengthened with angle steel will be decreased. In this paper, four RC columns strengthened with angle steel were tested under the fire condition. Temperature distribution in the column section, deformation as a function of time, failure pattern and fire resistance were obtained. The influence of the load ratio and eccentricity ratio on the fire resistance was also investigated. A finite element model was established to simulate the fire behavior of the columns. The results show that: ①when exposed to fire, epoxy adhesive will be evaporated, self-ignited and carbonized, which has a notable influence on the temperature field| ②under high temperature, cement mortar proof has a high probability to flake off due to the poor bond capacity between the mortar proof and steel| ③fire resistance of RC columns strengthened with angle steel decreases with the load level and eccentricity ratio| ④If there is no fire protection, the fire resistance of RC columns strengthened with angle steels can hardly satisfy the requirements in Chinese codes. The results of simulations agree well with the experimental data, which means the model can be used in the parameter study.
周立人 毛小勇 张翔. 角钢加固钢筋混凝土柱耐火极限试验研究[J]. 土木工程学报, 2017, 50(3): 35-43.
Zhou Liren Mao Xiaoyong Zhang Xiang. Experimental research on fire behavior of RC columns strengthened with angle steel. 土木工程学报, 2017, 50(3): 35-43.
