Durability study on RC beams strengthened with BFRP fabric

我们的经济在很大程度上依赖于桥梁的性能，它确保了我们城市和城镇之间的连接。加拿大的许多桥梁建于20世纪40年代和50年代，因此，这些桥梁中的大多数已经超过或即将超过其使用寿命。此外，许多桥梁的设计车辆荷载比目前的车辆荷载要小得多。造成这种情况的主要原因是，与20世纪40年代和50年代运营的车辆相比，目前的商业和农业车辆要重得多，尺寸也大得多。其中许多桥梁是用水泥混凝土建造的，另一些是用结构钢或木材建造的。尽管如此，如果这些桥梁要在设计使用年限之后长期使用，则需要立即予以加固和/或修复。另一种解决方案是用新的桥梁取代这些桥梁；然而，这在经济上不是一个可行的解决方案，因为这将花费数万亿美元的税收。因此，世界各地的研究人员一直在探索一种低成本、易应用的修复和加固技术，这种技术可以在对交通流量的干扰最小的情况下采用。这项新的修复和加固技术使用了各种纤维增强聚合物(FRP)织物，这些纤维增强聚合物织物使用强结构粘结剂附着在桥梁构件上。总的来说，研究表明，这种修复技术能够恢复力量，这种加固技术能够提供支撑较重车辆所需的额外力量。然而，这些研究没有注意到使用玻璃钢织物修复和/或加固的构件的耐久性和长期性能。因此，拟议的NSERC项目将迈出大胆的一步，确定使用FRP布加固的混凝土梁(梁)的耐久性和长期结构性能。本文研究的重点是玄武岩玻璃钢纤维布加固混凝土桥梁梁，玄武岩玻璃钢纤维布是一种新兴的、廉价的、绿色的玻璃钢材料。

Our economy largely depends on the performance of bridges, which ensure the connectivity among our cities and towns. Many bridges in Canada were built in the 1940s and 1950s and hence, the majority of these bridges have exceeded or will soon exceed their service life. Further, many of the bridges were designed for vehicle loads much less than current vehicle loads. The primary reason for this is that current commercial and farming vehicles are much heavier and greater in size than those operated in the 1940s and 1950s. Many of these bridges were built using cement concrete and others were built with structural steel or timber. Nonetheless, these bridges need immediate attention for strengthening and/or rehabilitation if they are to be kept in service for an extended period beyond their designed service life. An alternative solution would be to replace these bridges with new bridges; however, this is not an economically viable solution since this would cost trillions of tax dollars. Hence, researchers around the world have been exploring a low-cost and easy-to-apply rehabilitation and strengthening technique that can be adopted with minimum interruption to the traffic flow. This new rehabilitation and strengthening technique uses various fibre reinforced polymer (FRP) fabrics which are attached to the members of a bridge using strong structural adhesive. Researches, in general, have shown that this rehabilitation technique is able to restore the strength and this strengthening technique is able to provide additional strength required to support heavier vehicles. These studies, however, did not pay attention to the durability and long-term performance of the members rehabilitated and/or strengthened using FRP fabrics. Hence, the proposed NSERC project will take a bold step to determine the durability and long-term structural performance of concrete beams (girders) when strengthened using FRP fabric. This research will focus on concrete bridge girders strengthened with basalt FRP fabric, which is an emerging, cheaper, and greener FRP material.