Rehabilitation of structural concrete with fibre reinforced polymers

钢筋腐蚀是结构（钢筋或预应力）混凝土结构的头号劣化问题。拟议的研究将调查使用纤维增强聚合物（FRP）加固修复结构混凝土。将进行两个主要项目：(1)使用玻璃钢层压板进行修复：申请人的研究表明，使用玻璃钢系统进行修复可以通过限制钢筋腐蚀引起的膨胀力来减轻腐蚀。然而，迄今为止所做的工作主要集中在卸载状态下用FRP修复的构件以及腐蚀暴露后的测试。本研究将研究在腐蚀环境下FRP修复构件在使用荷载作用下的修复后结构性能和粘结性能。为腐蚀构件的玻璃钢修复建立分析模型和使用寿命预测模型。这项研究将对钢筋腐蚀的结构进行有效修复。(2) FRP加固预应力：申请人最近开发了一种用于碳纤维增强聚合物（CFRP）肌腱的新型锚固系统。碳纤维布加固是预应力混凝土的一种替代材料，但由于缺乏合适的锚，其使用非常有限。拟议的研究将采用UW开发的锚来抓住CFRP筋或条作为混凝土构件的加强措施。将建造钢筋混凝土梁或板，用CFRP筋进行外部预应力，并将在静荷载和循环荷载条件下进行测试。使用近表面安装（NSM）预应力CFRP筋加强将进行研究。利用碳纤维增强塑料（CFRP）筋的预应力系统的发展将促进这些材料在修复和新建造耐用结构中的使用。

Steel reinforcement corrosion is the number one deterioration problem for structural (reinforced or pre-stressed) concrete structures. The proposed research will investigate the use of fibre reinforced polymer (FRP) reinforcement to rehabilitate structural concrete. Two major projects will be pursued:     (1) Rehabilitation using FRP laminates: Research by the applicant has demonstrated that rehabilitation with FRP systems can mitigate corrosion by providing confinement to the expansive forces caused by reinforcing bar corrosion.  However, the work done to-date was focused on members repaired with FRP while in an unloaded state and tested after corrosion exposure. The proposed research will investigate the post-repair structural performance and bond performance of FRP repaired members under service loads in a corrosive environment. Analytical and service life prediction models will be developed for the FRP repair of corroded structural members.  This research will result in an effective rehabilitation of structures that have suffered steel reinforcement corrosion.     (2) Prestressing with FRP reinforcement: A novel anchor system for a carbon fibre reinforced polymer (CFRP) tendon has been recently developed by the applicant. CFRP reinforcement is an alternative material in prestressed concrete but has had very limited use mainly due to the lack of a suitable anchor. The proposed research will employ the UW developed anchor to grip CFRP tendons or strips as a strengthening measure for concrete members.  Reinforced concrete beams or slabs will be constructed, externally prestressed with CFRP tendons, and will be tested under static and cyclic loading conditions. Strengthening using near surface mounted (NSM) prestressed CFRP tendons will be investigated. The development of prestressed systems utilizing CFRP tendons will facilitate the use of these materials in rehabilitation and new construction of durable structures.