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(1 華北理工大學(xué)建筑工程學(xué)院， 唐山 063210； 2  河北省地震工程研究中心， 唐山 063210)

［摘要］通過3根軸心受壓混凝土柱和3根偏心受壓混凝土柱的足尺火災(zāi)試驗(yàn)，研究了不同表面含水率下，爆裂程度對鋼筋混凝土柱破壞模式、豎向位移及耐火極限的影響，對比分析了不同受壓方式下鋼筋混凝土柱火災(zāi)行為的異同。結(jié)果表明：隨養(yǎng)護(hù)周期增長，混凝土表面含水率下降，爆裂程度減輕，鋼筋混凝土柱耐火極限顯著提高；火災(zāi)作用下，偏心受壓柱試驗(yàn)后期產(chǎn)生突變的下降位移，相同條件下，偏心受壓柱的耐火極限低于軸心受壓柱的耐火極限；養(yǎng)護(hù)周期較短時(shí)，混凝土爆裂程度對柱耐火極限有較大影響，隨著養(yǎng)護(hù)時(shí)間增長，受壓方式對柱耐火極限的影響更加顯著。

［關(guān)鍵詞］鋼筋混凝土柱； 軸心受壓； 偏心受壓； 爆裂； 抗火性能； 表面含水率

中圖分類號：TU375-1文獻(xiàn)標(biāo)識碼：A文章編號：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

*國家自然科學(xué)基金（51608196），河北省自然科學(xué)基金（E2014209099），河北省高等學(xué)校青年拔尖人才計(jì)劃項(xiàng)目（BJ2018008）。

作者簡介：楊志年，博士，副教授，Email：yangzhinian1983@163.com。