Shear performance and size effect of CFRP strengthened RC beams

• Published in: International journal of mechanical sciences 2024-04, Vol.267, p.109012, Article 109012
• Main Authors: Zhang, Jiangxing, Li, Dong, Huang, Baihui, Wang, Xinrui, Jin, Liu, Du, Xiuli
• Format: Article
• Language: English
• Subjects: CFRP fiber ratio; CFRP strengthened RC beam; Meso-scale method; Shear performance; Shear-span ratio; Size effect law
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2024.109012

•A 3D meso-scale numerical simulation method of CFRP strengthened RC beams is established.•The coupling effect between shear-span ratio and CFRP fiber ratio is explored.•The quantitative relationship between the contribution of CFRP and shear-span ratio is analyzed.•The effect of shear-span ratio and CFRP fiber ratio on the size effect is investigated.•The shear strength size effect law of CFRP strengthened RC beams is proposed. In this study, a 3D meso-scale numerical simulation method is established for analyzing the shear failure of carbon fiber reinforced polymer (CFRP) strengthened RC beams without stirrups. The inhomogeneity of concrete, the bond-slip relationship between steel bars and concrete, and the interaction between CFRP and concrete are considered. Based on this method, effects of shear-span ratio and CFRP fiber ratio on the shear performance and nominal shear strength size effect of CFRP strengthened RC beams are investigated. Results indicate that the size effect of CFRP strengthened RC beams is obvious, however, the shear-span ratio has little impact on the size effect of nominal shear strength of RC beams. The CFRP fiber ratio enhances the shear strength of RC beams on the one hand, while weakens the shear size effect of RC beams on the other hand. However, its influence on the shear performance of RC beams remains basically unchanged with varying shear-span ratios, indicating that there is no coupling effect between the shear-span ratio and CFRP fiber ratio. The shear-span ratio significantly influences both the shear bearing capacity of RC beams and the shear contribution of CFRP sheets, with the increase in the shear-span ratio, the shear bearing capacity of RC beams decreases to varying degrees, and the shear contribution of CFRP sheets increases initially and then decreases. Finally, the shear strength size effect law (SEL) of CFRP strengthened RC beams is proposed, which can quantitatively describe the effects of the shear-span ratio and the CFRP fiber ratio. [Display omitted]