Integrity of Precracked Reinforced Concrete Retrofitted withComposite Laminates

复合层板加固预裂钢筋混凝土的完整性

• 批准号: 9634763
• 负责人: Oral Buyukozturk
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9634763&HistoricalAwards=false
• 关键词: Integrity; Precracked; Reinforced; Concrete; Retrofitted

9634763 Buyukozturk The objective of this research is to provide a scientific basis for the underlying mechanisms of fracture and delamination of precracked reinforced concrete retrofitted using fiber-reinforced plastic (FRP) composite laminates, and to develop design guidelines for efficient applications and safe engineering designs of these systems. Laminated beams have been observed to fail through several mechanisms, including yielding of the laminate, crushing of the concrete, and brittle fracture through delamination of the composite from the concrete. Available experience has shown that fracture through delamination can occur at stress below material limits and under loads within normal service. The emphasis of this study will be on delamination and its causes, specifically in the presence of combined flexural and shear cracks in the retrofitted concrete beam. Fracture mechanics based combined experimental and numerical studies of failure initiating from the concrete-adherent-laminate interface region will be performed on concrete beams laminated with fiber-reinforced plastics. Parametric investigations involving different materials and construction techniques will determine the optimum effectiveness of these combinations. The project will have the collaboration of Swiss Federal Laboratories for Materials Testing and Research (EMPA) in Switzerland where large scale tests will be conducted with consistent parameters as will be used in this study. This research is expected to provide a fundamental knowledge of FRP delamination, and be developing the needed design guidelines to have a direct impact on engineering application in the retrofitting field in an efficient, economical, and safe manner. ***

9634763 Buyukozturk 这项研究的目的是为使用纤维增强塑料 (FRP) 复合材料层压板改造的预裂钢筋混凝土的断裂和分层的基本机制提供科学依据，并为这些系统的高效应用和安全工程设计制定设计指南。 据观察，层压梁会通过多种机制失效，包括层压板的屈服、混凝土的压碎以及复合材料与混凝土分层导致的脆性断裂。 现有经验表明，在低于材料极限的应力和正常使用中的负载下，可能会发生分层断裂。 本研究的重点是分层及其原因，特别是在改造混凝土梁中存在弯曲和剪切裂缝的情况下。 将对纤维增强塑料层压混凝土梁进行基于断裂力学的组合实验和数值研究，研究从混凝土-粘附-层压板界面区域开始的失效。 涉及不同材料和施工技术的参数研究将确定这些组合的最佳效果。 该项目将与位于瑞士的瑞士联邦材料测试与研究实验室 (EMPA) 合作，该实验室将使用与本研究中使用的一致参数进行大规模测试。 这项研究预计将提供 FRP 分层的基础知识，并制定所需的设计指南，以高效、经济和安全的方式对改造领域的工程应用产生直接影响。 ***