Rehabilitation of wooden utility poles with sprayed-GFRP composites

与其他建筑材料相比，木杆有很大的优势，因为木材是可再生的、可持续的，在制造过程中产生的温室气体较少，并提供了大气碳的长期储存库。木制电线杆的平均使用寿命为30至40年；然而，由于腐烂、机械损坏、气候变化和设计环境变化等多种因素，这一使用寿命可能会缩短。尽管防腐处理和定期维护可以延长电杆的使用寿命，但在某些时候，电杆会失去承载能力，容易发生故障，从而导致停电、昂贵的维修和其他经济损失。例如，马尼托巴省水电公司在马尼托巴省拥有60多万根配电杆。如果其中3%的电线杆每年需要更换，成本可能接近540万美元。另一方面，修复这些杆子不仅可以节省时间和金钱，还可以减少树木的消耗和处理木材的成本。在过去的二十年里，纤维增强聚合物(FRP)材料由于其高强度和耐腐蚀性，已成功地应用于民用基础设施的建设和修复。目前对混凝土和木结构的FRP修复是通过在受损区域周围提供FRP包裹或夹克来进行的。然而，一种相对较新的技术--喷涂FRP复合材料--被提出用于修复缺陷的木杆。与传统的玻璃钢夹套相比，该技术具有施工方便、表面处理少、不易剥离、在不规则和难以接触的表面上具有更高的有效性、更好的变形性和更好的成本效益等优点。这项研究的目的是开发使用喷涂FRP复合材料修复木质电线杆的设计方法。拟议的工作既包括在不同恢复方案下直到失效的足尺杆件的实验测试，也包括使用有限元分析的分析研究。这将使翻新的木制电线杆具有更好的性能、更好的耐用性，并减少水电分配机构的维护成本。

Wood poles have substantial advantages over other construction materials because wood is renewable, sustainable, generates less greenhouse gases during manufacturing and provides a long-term repository for atmospheric carbon. Wood utility poles on average serve for 30 to 40 years; however, this service life can be shortened due to several factors including decay, mechanical damage, weathering and changing design circumstances. Even though a preservative treatment and regular maintenance can extend the pole life, at some point, the pole loses its load carrying capacity and becomes vulnerable to failure, which leads to power outage, costly repair and other economic losses. For example, Manitoba Hydro has over 600,000 power distribution poles across Manitoba. If 3% of these poles need replacement annually, the cost can approach $5.4 million. On the other hand, rehabilitation of these poles will not only save time and money but also will reduce the consumption of trees and cost of treated wood disposal. In the last two decades, fibre-reinforced polymer (FRP) materials have been successfully used in the construction and rehabilitation of civil infrastructure due to their high strength and corrosion resistance. Current FRP rehabilitation of concrete and wood structures are conducted by providing FRP wraps or jackets around the damaged area. However, a relatively new technique, sprayed-FRP composites, is proposed to rehabilitate deficient wood poles. This technique offers advantages over conventional FRP jackets, such as easier application, less surface preparation, less vulnerability to debonding, higher effectiveness on irregular and difficult-to-access surfaces, better deformability, and better cost effectiveness. The objective of this study is to develop design methodologies for rehabilitating wood utility poles using sprayed-FRP composites. The proposed work includes both experimental tests on full-scale poles up to failure under different rehabilitation scenarios and analytical investigation using finite element analysis. This will lead to refurbished wood utility poles with improved performance, better durability, and that incur fewer maintenance costs for hydro distribution agencies.