The context of this study is the shear strengthening analysis of a concrete beam using a new natural material. This paper presents the experimental results of the shear reinforcement of concrete beams with a flax fiber reinforced polymer (FFRP) using the External Bonding method (EB) and the Near Surface Mounted method (NSM). A total of 16 beams were tested with three point bending tests. The beams had rectangular sections and a 2-meter span and a T sections with a 2.5 m span. The following parameters were investigated: (i) the percentage of flax reinforcement (continuous vs non continuous), (ii) the percentage of transversal steel (stirrups), (iii) the method of reinforcement (EB vs NSM), (iv) and the interaction between the FFRP and the stirrups.

The results obtained showed that the ultimate load increased by 10% to 35% for these reinforced beams; however, this type of reinforcement did not contribute to a modification of the type of failure or the behavior of post failure. The results also showed that the NSM method is more efficient than the EB method. In addition, the presence of transversal reinforcement reduces the contribution of flax fibers in the shear resistance of the beam. Finally, the experimental results obtained are compared succefully to different design code equations.

这项研究的背景是使用新的天然材料对混凝土梁进行抗剪加固分析。本文介绍了使用外部粘结法（EB）和近表面贴装法（NSM）用亚麻纤维增强聚合物（FFRP）剪切混凝土梁的实验结果。通过三点弯曲测试对总共16条光束进行了测试。横梁具有矩形截面和2米跨度，T截面具有2.5 m跨度。研究了以下参数：（i）亚麻增强的百分比（连续与非连续），（ii）横向钢的百分比（箍筋），（iii）增强方法（EB与NSM），（iv）和FFRP和箍筋之间的相互作用。

结果表明，这些增强梁的极限荷载增加了10％至35％。但是，这种类型的加固并没有有助于破坏类型的改变或后期破坏的行为。结果还表明，NSM方法比EB方法更有效。另外，横向增强的存在减少了亚麻纤维在梁的抗剪强度中的贡献。最后，将获得的实验结果成功地与不同的设计代码方程式进行比较。