A comprehensive study on enhancing the fire resistance of Glass Fiber-Reinforced Polymer (GFRP) reinforced concrete columns and slabs

本项目旨在提供玻璃纤维增强聚合物(GFRP)加固混凝土构件在火灾中的整体研究，即柱和板。这项研究将有三个主要的试验阶段：(1)在环境室内进行MST筋的标准拔出试验；(2)将对板端有膨胀涂层的GFRP筋混凝土板进行中等和全尺寸的标准火灾试验；(3)将在北美首次进行完全由GFRP筋加固的全尺寸柱的标准火灾试验。到目前为止，FRP筋的粘结强度在高温下的损失和劣化被认为是FRP筋混凝土构件的耐火性能低于钢RC构件的主要原因。试验结果表明，如果FRP筋两端的温度保持在其玻璃化转变温度以下，FRP RC构件的粘结破坏将显着改善。为此，建议保护FRP钢筋混凝土构件的锚固区不受直接火灾的影响，以延缓温度传播到锚固区内嵌的FRP钢筋。最近，超薄膨胀涂层的应用显示了良好的效果，延迟了温度传播到混凝土中。这种薄膜膨胀型涂层极大地保护结构元件免受火灾中可能发生的严酷温度的影响。膨胀型涂料是传统被动式防火涂层的一种易于涂装和成本效益高的替代产品。前面提到的试验将用于检查GFRP钢筋混凝土柱的性能，以及GFRP箍筋和GFRP纵筋在火灾中的性能。通过这一合作关系，MST钢筋将对GFRP RC柱的耐火性能充满信心，并为提高GFRP RC板的耐火性能提供切实的措施。加拿大规范，如CSA-S806，是专门为推广GFRP RC结构而开发的。这项研究的结果将为加拿大制定CSA-S806条款提供知识。

This project aims to provide a holistic investigation of Glass fibre reinforced polymer (GFRP) reinforced concrete members in fire, namely columns and slabs. This research will have three main experimental phases: (1) standard pullout tests on MST bars in an environmental chamber; (2) intermediate and full-scale standard fire tests will be conducted on GFRP-reinforced concrete slabs with intumescent coating at the ends of the slabs; and (3) a full-scale column entirely reinforced with GFRP bars will be tested under standard fire for the first time in North America. To date, the loss and degradation of bond strength of FRP reinforcing bars at high temperatures has been identified as the main cause of the inferior fire performance of FRP-reinforced concrete (RC) elements compared to steel RC ones. The test results have revealed that if temperatures at both ends of an FRP bar remain below its glass transition temperature the bond failure of the FRP RC member will significantly improve. To achieve this, the anchorage zones in FRP RC members are recommended to be protected from direct fire exposures to delay the temperature propagation into the embedded FRP reinforcing bars at the anchorage zones. Recently, the application of intumescent coatings with very thin layers has shown promising results with delayed temperature propagation into the concrete. The thin-film intumescent coatings greatly protect structural elements against severe temperatures that can occur in fires. The intumescent coatings are an easy-to-apply and cost-effective alternative to conventional passive fire protection layers. The previously mentioned tests will be used to examine the performance of GFRP reinforced concrete columns, as well as the behaviour of GFRP stirrups and GFRP longitudinal bars during a fire. Through this partnership, MST Rebar will be confident in the fire resistance of GFRP RC columns and offer practical measures to enhance the fire resistance of GFRP RC slabs. Canadian codes, such as CSA-S806, are specifically developed to promote GFRP RC structures. The outcome of this research will provide knowledge in developing provisions for CSA-S806 in Canada.