Performance of steel reinforced concrete columns after exposure to fire: Numerical analysis and application
Performance of steel reinforced concrete columns after exposure to fire: Numerical analysis and application
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通讯作者：
Lin-Hai Han;Kan Zhou;Q. Tan;T. Song
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作者：
Lin-Hai Han;Kan Zhou;Q. Tan;T. Song
：钢筋混凝土 (SRC) 柱的优点之一是，混凝土外壳降低了钢型材在全方位火灾情况下达到的最高温度。对于遭受火灾的 SRC 柱，更好地了解其火灾后的性能有助于其修复和再利用。本文对 SRC 柱的火灾后性能进行了数值研究。结果表明，截面为600×600 mm的SRC柱在受到全范围火加热45 min和随后的139 min线性冷却阶段后，保留了原始承载能力的0.87倍。 SRC柱完全冷却至环境温度后，型钢承载的荷载比例增加至73%，明显高于环境温度下的水平（20%）。参数研究的结果表明，火灾持续时间、横截面尺寸、长细比和混凝土强度等许多因素对火灾后残余强度有显着影响。将数值方法应用于火灾建筑中SRC柱的火灾后评估，并进行了案例研究。暴露在火中后，SRC 柱的抗压能力降低了 4%。通过使用所提出的修复方法，与火灾暴露前相比，抗压能力可以恢复11%。
: One advantage of steel reinforced concrete (SRC) columns is that the concrete encasement reduces the maximum temperature attained by the steel section in the full-range fire situation. For fire-exposed SRC columns, a better understanding of their post-fire performance can facilitate their rehabilitation and re-use. This paper presents a numerical study into the post-fire performance of SRC columns. Results show that an SRC column of 600 600 mm in cross-section retained 0.87 times of the original load-bearing capacity after exposure to full-range fire with a heating duration of 45 min and a subsequent linear cooling down phase of 139 min. After the SRC column fully cooled down to ambient temperature, the proportion of load carried by the steel section increased to 73%, significantly higher than the level at ambient temperature (20%). Results of the parametric study revealed that a number of factors, i.e., duration of fire exposure, cross-sectional size, slenderness ratio and concrete strength, significantly affected the post-fire residual strength. The numerical method was applied to the post-fire assessment of the SRC columns in a fire-exposed building and a case study is presented. The resistance of the SRC column to compression reduced by 4% after fire exposure. By using the proposed repair method, the resistance to compression can be recovered by 11% compared to that before fire exposure.