预制CFRP筋增强板加固素石板受弯性能试验研究

来源期刊:中南大学学报(自然科学版)2021年第2期

论文作者:叶勇 苗伟 郭子雄 张世江

文章页码:589 - 599

关键词:石结构;抗弯加固;CFRP筋;石板;预制增强板

Key words:stone structure; flexural strengthening; CFRP bar; stone slab; prefabricated strengthening sheet

摘    要:提出一种预制CFRP筋增强板抗弯加固技术,实现对既有传统石结构中素石板的快速原貌加固。为验证该技术的加固效果,对石板试件进行受弯性能加载试验,研究加固方式、增强板宽度、CFRP筋直径和配筋率对受弯性能的影响。研究结果表明:将预制CFRP筋增强板粘贴于素石板受拉面的加固技术可使石板的破坏形态由脆性断裂转变为延性良好的弯曲破坏,石板的受弯承载力和变形能力得到显著提高;CFRP筋增强板与被加固石板之间的界面黏结性能良好,加载试验过程中未出现界面剥离和CFRP筋滑移现象,加固后的石板具有良好的整体工作性能;在加载过程中,CFRP筋增强板加固石板试件和嵌埋CFRP筋组合石板试件的截面应变分布和发展规律基本相同,均满足平截面假定;与采用表层嵌埋CFRP筋加固的石板相比,采用预制CFRP筋增强板加固的石板破坏形态相近,同时受弯承载力有所提高;随着CFRP筋配筋率和增强板宽度的增大,预制CFRP筋增强板的加固效果更为显著。配筋率相近时,采用较小直径的CFRP筋可更好地发挥加固筋的材料性能;条带增强板加固可有效提高素石板的受弯性能,且质量较轻,在实际加固工程中更具有易于施工的优势。

Abstract: A strengthening technique by using prefabricated CFRP-reinforced stone sheets was proposed to achieve easy construction and maintain the appearance of the strengthened stone members. In order to verify the effectiveness of the strengthening technique, a series of bending tests were carried out to study the effect of the strengthening method, width of the prefabricated CFRP-reinforced stone sheet, diameter of CFRP bar, and reinforcement ratio on flexural performance. The results show that, the strengthening technique by using prefabricated CFRP-reinforced stone sheets effectively improve the flexural behaviour of bare stone slabs by both shifting the failure mode from brittle fracture to ductile bending and increasing the load-bearing capacity and deformation capacity. Good interfacial bond is found between the prefabricated CFRP-reinforced stone sheet and the stone slab, and no debonding or slipping of CFRP bars occurs during testing, ensuring the improved flexural behaviour of the strengthened stone slabs. During the testing, the strain distribution and development rule of the stone slab strengthened with prefabricated CFRP-reinforced stone sheets are similar to those of the stone slab strengthened with NSM CFRP bars. Compared with the stone slabs strengthened with NSM CFRP bars, the stone slabs strengthened with prefabricated CFRP-reinforced stone sheets have a similar failure mode but an increased flexural strength. As the reinforcement ratio or width of the prefabricated CFRP-reinforced stone sheet increases, a more obvious strengthening effect is achieved. With the same reinforcement ratio, a smaller diameter of CFRP bar leads to better utilization of the CFRP material. The bare stone slab strengthened with prefabricated CFRP-reinforced stone strips exhibits significant enhancement in flexural performance, as well as a lighter self-weight, which renders easy construction in the practical application.

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号