标准火灾下配筋圆钢管混凝土柱温度场试验研究

Temperature field of circle reinforced concrete-filled steel tube under standard ISO 834 fire

为研究ISO 834标准火灾升降温作用下配筋圆钢管混凝土柱的温度场分布规律,首先进行了2根配筋圆钢管混凝土柱的温度场试验,升温时间分别为30 min和60 min,进而在确定材料参数,分析传热方程的基础上,利用有限元软件ABAQUS建立模型,模型结果与试验结果吻合较好.结果表明:沿柱纵向位置不同的测点温度发展规律一致,试件轴向温度场均匀分布;试件内部不同位置存在温度梯度,越靠近截面中心处,所能达到的最高温度越低,达到最高温度的时间越迟缓,降温也越缓慢;在升温过程中,混凝土材料温度达100℃时,形成一个温度平台,配筋对混凝土温度分布影响可以忽略.

In order to study the distribution regularity of temperature field under the condition of ISO 834 standard fire and free cooling of the circular concrete-filled tubular column with reinforcements, this paper firstly carried out an experiment of two circular concrete-filled tubular columns with reinforcements under the fire which were last for 30 minutes and 60 minutes. Then, the study used simulation software ABAQUS to set up models which match well with the test specimen with the same parameter of materials as well as the same heat transfer equation. The results of study show that the temperature of measuring point located in the longitude develops in a same consistent regularity, and the temperature field in longitude of the specimen are distributed uniformly. However, there is a grad of temperature existing inside the column section that the temperature is lower towards the core of the section. The closer to the core, the lower maximum temperature can reach. It takes more time to get the maximum temperature and more slowly in getting to lower temperature as well. During the temperature rising period, the concrete formed a temperature platform in 100℃, so the effect of the reinforcements can be ignored.