Wang Hai-Tao, Bian Zhi-Ning, Xu Guo-Wen, Chen Min-Sheng, Xiong Hao, Liu Sai-Sai
College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China.
China Construction Eighth Engineering Division Co., Ltd., Shanghai 200122, China.
Polymers (Basel). 2022 Dec 15;14(24):5498. doi: 10.3390/polym14245498.
Externally bonded carbon-fiber-reinforced polymer (CFRP) technology can be used by different methods based on the anchorage device, CFRP type, and prestressing/nonprestressing. However, a direct comparison between the strengthening efficacies of different methods is still lacking. Seven large-scale RC beams were tested in this study to investigate the influences of the anchorage method, CFRP type, prestress, and prestressing system on the flexural strengthening efficacy of RC beams. The test results showed that the ultimate load increased by 38.3%, whereas the cracking and yielding loads were slightly affected when the anchorage method was enhanced from CFRP U-wraps to wedge-clamp anchors. The CFRP plate and CFRP sheet could provide a rather close flexural strengthening efficacy under the same CFRP strengthening amount. Compared to the nonprestressed CFRP plate, the prestressed CFRP plate was highly superior in improving the flexural behavior of RC beams. The cracking, yielding, and ultimate loads of the prestressed CFRP-strengthened specimens were 57.1%, 22.9%, and 5.9%, respectively, higher than those of the nonprestressed CFRP-strengthened specimen with an effective anchorage. The two types of prestressing systems based on the adhesive-friction anchor and wedge-clamp anchor were proven to be effective for flexural strengthening of RC beams with prestressed CFRP plates, and they could provide almost the same strengthening effect.
基于锚固装置、碳纤维增强复合材料（CFRP）类型以及预应力/非预应力情况，外部粘贴CFRP技术可采用不同方法。然而，目前仍缺乏对不同方法加固效果的直接比较。本研究对七根大型钢筋混凝土（RC）梁进行了试验，以研究锚固方法、CFRP类型、预应力和预应力体系对RC梁抗弯加固效果的影响。试验结果表明，当锚固方法从CFRP U型箍增强为楔形夹具锚时，极限荷载提高了38.3%，而开裂荷载和屈服荷载受到的影响较小。在相同的CFRP加固量下，CFRP板和CFRP片材能提供相当接近的抗弯加固效果。与非预应力CFRP板相比，预应力CFRP板在改善RC梁的抗弯性能方面具有显著优势。预应力CFRP加固试件的开裂荷载、屈服荷载和极限荷载分别比有效锚固的非预应力CFRP加固试件高57.1%、22.9%和5.9%。基于粘结摩擦锚和楔形夹具锚的两种预应力体系被证明对采用预应力CFRP板的RC梁抗弯加固有效，且它们能提供几乎相同的加固效果。
