Fire behaviour of thermally insulated RC beams strengthened with EBR-CFRP strips: Experimental study
Fire behaviour of thermally insulated RC beams strengthened with EBR-CFRP strips: Experimental study
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DOI：
10.1016/j.compstruct.2014.11.063
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发表时间：
2015-04-01
影响因子：
6.3
通讯作者：
Correia, J. R.
中科院分区：
文献类型：
--
作者：
Firmo, J. P.;Correia, J. R.
本文对采用外部粘合碳纤维增强聚合物 (CFRP) 条带进行弯曲加固的钢筋混凝土 (RC) 梁的防火性能进行了实验研究。研究了不同的防火方案，包括沿梁底部拱腹设置较薄的隔热层，以及在 CFRP 锚固区域设置较厚的隔热层。本次调查的主要目标是 (i) 进一步深入了解 CFRP 加固系统在火灾期间的结构有效性，以及 (ii) 评估上述防火策略在扩展 CFRP 机械贡献方面的效率；此外，还评估了（iii）在CFRP条上应用机械锚固和（iv）使用具有高玻璃化转变温度（T-g）的粘合剂的（潜在）有益效果。获得的结果表明，即使在梁中心区域的 CFRP 条脱粘后，加固系统也能够通过拉索机构保持其结构有效性；可以将 CFRP 系统的耐火极限延长至 70 分钟，并且当锚固区域粘合剂的平均温度达到 1.2 x T-g 至 1.5 x T-g 时，加固系统就会发生脱粘。 (C) 2014 Elsevier Ltd. 保留所有权利。
This paper presents experimental investigations on the fire behaviour of reinforced concrete (RC) beams flexurally strengthened with externally bonded carbon fibre reinforced polymer (CFRP) strips. Different fire protection schemes were studied, comprising a thinner insulation layer along the bottom soffit of the beams and a thicker one at the CFRP anchorage zones. The main goals of this investigation were (i) to understand in further depth the structural effectiveness of CFRP strengthening systems during fire and (ii) to evaluate the efficiency of the above-mentioned fire protection strategy in extending the CFRP mechanical contribution; in addition, the (potential) beneficial effects of (iii) applying mechanical anchorages at the CFRP strips, and (iv) using a bonding adhesive with high glass transition temperature (T-g) were also evaluated. The results obtained showed that the strengthening system is able to retain its structural effectiveness through a cable mechanism, even after the CFRP strip debonding in the central zone of the beams; it was possible to extend the fire endurance of the CFRP system up to 70 min and the debonding of the strengthening system occurred when the average temperature in the adhesive at the anchorage zones attained values from 1.2 x T-g to 1.5 x T-g. (C) 2014 Elsevier Ltd. All rights reserved.