(1 华北理工大学建筑工程学院， 唐山 063210； 2  河北省地震工程研究中心， 唐山 063210)

［摘要］通过3根轴心受压混凝土柱和3根偏心受压混凝土柱的足尺火灾试验，研究了不同表面含水率下，爆裂程度对钢筋混凝土柱破坏模式、竖向位移及耐火极限的影响，对比分析了不同受压方式下钢筋混凝土柱火灾行为的异同。结果表明：随养护周期增长，混凝土表面含水率下降，爆裂程度减轻，钢筋混凝土柱耐火极限显著提高；火灾作用下，偏心受压柱试验后期产生突变的下降位移，相同条件下，偏心受压柱的耐火极限低于轴心受压柱的耐火极限；养护周期较短时，混凝土爆裂程度对柱耐火极限有较大影响，随着养护时间增长，受压方式对柱耐火极限的影响更加显著。

［关键词］钢筋混凝土柱； 轴心受压； 偏心受压； 爆裂； 抗火性能； 表面含水率

中图分类号：TU375-1文献标识码：A文章编号：1002-848X(2019)17-0103-05

Research on effect of surface moisture content on spalling degree and fire resistance rating of reinforced concrete columns

Yang Zhinian1,2, Zhu Huanran1,2, Li Qiuming1,2, Wang Xingguo1,2

(1 College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan 063210, China;  2 Earthquake Engineering Research Center of Hebei Province, Tangshan 063210, China)

Abstract:Based on the full-scale fire tests of three axially compressed concrete columns and three eccentrically compressed concrete columns, the effects of spalling degree on the failure mode, vertical displacement and fire resistance limit of reinforced concrete columns under different surface moisture contents were studied, and the similarities and differences of fire behavior of reinforced concrete columns under different compression modes were compared and analyzed. The results show that with the increase of curing period, the surface moisture content of concrete decreases, the degree of cracking decreases, and the fire resistance limit of reinforced concrete columns increases significantly; under the fire, the abrupt drop displacement occurs in the later stage of eccentric compression column test, and the fire resistance limit of eccentric compression column is lower than that of axial compression column under the same conditions; when the curing period is short, the degree of concrete spalling has a great influence on the fire resistance limit of columns, and the influence of compression mode on the fire resistance limit of columns is more significant with the increase of curing time.

Keywords:reinforced concrete column; axial compression; eccentric compression; spalling; fire resistance; surface moisture content

*国家自然科学基金（51608196），河北省自然科学基金（E2014209099），河北省高等学校青年拔尖人才计划项目（BJ2018008）。

作者简介：杨志年，博士，副教授，Email：yangzhinian1983@163.com。