Development of advanced strengthening technique for steel structures using externally bonded FRP members

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04238
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22020:Structure engineering and earthquake engineering-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Nakamura Hitoshi 東京都立大学, 都市環境科学研究科, 准教授 (70264596)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 構造工学・地震工学 / 構造・機能材料 / 維持管理工学 / 補修・補強 / FRP部材 / 鋼構造物 / 接着接合 / 耐久性

Outline of Final Research Achievements

In response to the demand for efficient maintenance and management of infrastructures, this study proposes a repair and strengthening method for existing steel structures using FRP, which is lightweight and has excellent durability. The objective of this study is to develop the repair and strengthening techniques for existing steel structures utilizing advanced FRP members by bringing fibers to the construction site and impregnating and bonding resin to the reinforcing fibers using a molding technique called VaRTM (Vacuum assisted Resin Transfer Molding Method). In this study, (1) the strength and durability of adhesive joints with steel members were investigated, and (2) the stacking configuration and cross-sectional stiffness of FRP members were experimentally and analytically investigated. Furthermore, Furthermore, efficient adhesive bonding and optimal installation of FRP members are shown for steel members required for repair and strengthening.

Free Research Field

土木工学

Academic Significance and Societal Importance of the Research Achievements

FRP部材を用いた接着工法は，孔明け等が不要で，施工が簡便であるため，種々の既設鋼構造物の補修・補強に適用できると考えられるが，接着接合部のはく離や長期耐久性に対する懸念やFRPの効果的な配置が課題であった．本研究の成果より，複合応力を考慮した接着強度，接着接合部のクリープ特性，疲労耐久性が定量的に示されたこと，また，補修・補強が必要な鋼部材に対するFRP部材の積層・断面構成の配置の考え方が示されたことから，FRP部材の高度利用とその普及に貢献するものと考えている．