Title: Flexural Fatigue Behavior of RC Beams Strengthened with FGREM Composites

Author(s): Aohan Zheng, Siyu Wang, Yiyan Lu, and Shan Li

Publication: Structural Journal

Volume: 119

Issue: 6

Appears on pages(s): 205-219

Keywords: engineered cementitious composite (ECC); fatigue loading; fiber-reinforced polymer (FRP) grid; flexural performance; reinforced concrete (RC) beam; strengthening

DOI: 10.14359/51736112

Date: 11/1/2022

Abstract:
In this study, the flexural fatigue performance of reinforced concrete (RC) beams strengthened with a fiber-reinforced polymer (FRP) grid-reinforced engineered cementitious composite (ECC) matrix was experimentally investigated. An FRP grid-reinforced ECC matrix (FGREM) composite strengthening layer was applied by reinstating the original concrete layer to a predetermined depth. The load level, FRP grid type, and strengthening amount were considered as test variables. The ultimate fatigue failure of the strengthened beams was found to be governed by the fracture of tensile steel bars. However, premature end debonding could be triggered in specimens subject to excessive strengthening. Furthermore, the fatigue life of the strengthened beams was distinctively improved owing to the relieved tensile stress range of the steel reinforcements. By relieving the damage accumulation of the constituent materials, this strengthening system can effectively ameliorate cracking, which is of great significance to the degeneration of stiffness and the development of deflections.