Tworzewski Paweł, Bacharz Kamil
Department of Building Structures, Kielce University of Technology, Al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland.
Department of Strength of Materials and Structures Diagnostics, Kielce University of Technology, Al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland.
Materials (Basel). 2025 May 31;18(11):2579. doi: 10.3390/ma18112579.
The work presents and examines a fiber anchoring system of NSM CFRP strips proposed for strengthening RC beams. The study included 11 beams: 3 unstrengthened beams, 3 beams strengthened with NSM CFRP strip without anchorage, and 5 beams strengthened with NSM CFRP strips with additional anchorage in two variants (the fiber anchor wrapped around the CFRP strip end and fan-folded on the beam surface; the fiber anchor connected with a 20 cm overlap to the strip). All beams were loaded until failure with two concentrated forces (four-point loading test). The measurements were carried out using digital image correlation (DIC). The obtained ultimate load values reached an average of 43.5 kN for unstrengthened beams, while for strengthened beams, they ranged between 56.6 kN and 60.2 kN. The strengthening efficiency was comparable for all beams regardless of the anchorage used and ranged from 29% to 37%. All strengthened beams failed due to strip debonding. The obtained results did not allow confirmation of the effectiveness of the proposed anchoring system. Detailed analysis showed that the lack of anchoring effectiveness was related to the debonding initiating factor, i.e., vertical crack opening displacement, which has not been described in proper detail by the researchers.
该研究介绍并检验了一种用于加固钢筋混凝土梁的新型粘贴碳纤维板条（NSM CFRP）纤维锚固系统。该研究共包括11根梁：3根未加固梁、3根粘贴NSM CFRP板条但未设置锚固的梁，以及5根粘贴NSM CFRP板条并设置了两种形式额外锚固的梁（一种是将纤维锚缠绕在CFRP板条端部并在梁表面呈扇形折叠；另一种是纤维锚与板条搭接20 cm）。所有梁均通过两点集中荷载加载直至破坏（四点加载试验）。测量采用数字图像相关技术（DIC）。未加固梁的平均极限荷载值为43.5 kN，而加固梁的极限荷载值在56.6 kN至60.2 kN之间。无论采用何种锚固方式，所有梁的加固效率相当，在29%至37%之间。所有加固梁均因板条脱粘而破坏。所得结果无法证实所提出锚固系统的有效性。详细分析表明，锚固失效与脱粘引发因素有关，即垂直裂缝开口位移，而研究人员对此未进行适当详细的描述。
