Serviceability and strength of FRP reinforced concrete structures

加拿大的主要挑战之一是有效地维护和扩大我们广泛的桥梁、公路和其他关键基础设施网络，这些基础设施对加拿大人的生活质量以及该国的经济竞争力和未来发展至关重要。为了迎接这一挑战，我们需要建设新的基础设施，并维护和修复现有的基础设施。其中很大一部分是由钢筋混凝土制成的，由于除冰盐导致钢筋的腐蚀，混凝土桥梁、停车结构、电线杆等正在迅速恶化。这个问题可以通过用纤维增强聚合物(FRP)取代钢筋来解决。玻璃钢具有耐腐蚀性和耐久性，可用于现有结构的改造和新的钢筋和预应力混凝土结构的加固。然而，安全、有效和经济地使用玻璃钢需要有严格的科学原则支持的方法和技术，并经过适当的实验验证。此外，为了确保研究成果在实践中得到应用，需要对严格的方法进行简化，以便纳入设计规范。拟开展的研究旨在实现上述目标，解决玻璃钢混凝土结构设计和加固中的一些重要问题。为了确保FRP钢筋混凝土结构的安全，将对其在剪切、扭转和弯矩引起的复合应力场下的性能和强度进行研究，并提出设计建议。为了防止FRP加固板-角柱节点在剪力和不平衡弯矩共同作用下的意外冲切破坏，本研究将首次对这一问题进行研究。在拟议的研究中，研究了新的锚固和加固系统，以防止过早分层，特别是在混凝土构件为提高剪切强度而进行改造的情况下的分层。研究结果将用于制定相对简单的程序，供结构设计者应用，并纳入设计标准。

One of the major challenges in Canada is to effectively maintain and expand our extensive networks of bridges, highways and other key elements of infrastructure that are essential to the quality of life of Canadians and to the economic competitiveness and future development of the country. To meet this challenge, we need to build new infrastructure and maintain and repair existing ones. A significant portion of these is made of reinforced concrete, and concrete bridges, parking structures, utility poles, etc. are rapidly deteriorating due to corrosion of steel reinforcement caused by deicing salts. This problem can be solved by replacing steel reinforcement by fibre reinforced polymers (FRP). FRP are corrosion resistant and durable and can be used for the retrofit of existing structures and reinforcement of new reinforced and prestressed concrete structures. However, safe, effective and economic use of FRP needs methods and techniques that are underpinned by rigorous scientific principles, validated by appropriate experiments. Furthermore, to ensure that the results of research are applied in practice, the rigorous methods need be simplified for inclusion in design codes. The proposed research is aimed at fulfilling the above objectives with respect to a number of important problems in the design and retrofit of concrete structures involving FRP. To ensure the safety of FRP reinforced concrete structures, their behaviour and strength under combined stress fields caused by shear, torsion and moment will be investigated and design recommendations will be made. To prevent unexpected punching shear failure in FRP reinforced slab- corner column connections under combined shear and unbalanced moment, this problem will be investigated for the first time in the proposed research. In the proposed study novel anchoring and retrofit systems are investigated to prevent premature delamination, with particular focus on delamination in cases of concrete members retrofitted for increased shear strength. The research results will be used to formulate relatively simple procedures for application by structural designers and for inclusion in design standards.