Near Surface Mounted (NSM) fibre reinforced polymer (FRP) bars is an effective technique of improving the performance of timber beams. Despite the potential of NSM technique, literature remains limited, whilst there is not any standard method for the prediction of the NSM FRP timber flexural capacity. Extending the pool of experimental data and thus the understanding of FRP strengthened timber structures, the present paper reports an experimental study of timber beams reinforced with glass and basalt FRP bars. Moreover, the paper presents a general theoretical model in order to estimate the moment resistance of the NSM FRP timber beams. The experimental study examined white spruce timber specimens in two reinforcement configurations; one with reinforcement bars only on the tension zone and one with reinforcement bars both on the tension and the compression zone. Control specimens were also included for comparison purposes. All beams had a rectangular cross-section of 70 × 215 mm and were loaded under four-point bending configuration with a 2.3 m span. A total of 20 specimens were tested under displacement control quasi-static monotonic loading. The main failure mechanism observed for both NSM FRP reinforced and unreinforced specimens was brittle tensile failure of the timber at the tensile zone. The load–deflection curves, the strain distribution profiles and the failure modes were discussed. It was observed that a significant increase on the ultimate load (33–69%) and the flexural stiffness (22–33%) of the timber beams can be achieved due to the NSM reinforcement. The proposed theoretical model for the ultimate strength of NSM FRP strengthened timber beams is assessed on the basis of the test results and collated data, showing a good comparison between the experimental and theoretical results.

近表面安装（NSM）纤维增强聚合物（FRP）钢筋是提高木梁性能的有效技术。尽管NSM技术具有潜力，但文献仍然有限，而没有任何标准方法可用于预测NSM FRP木材的挠曲能力。本文扩大了实验数据的范围，从而加深了对FRP加固的木材结构的了解，对玻璃和玄武岩FRP筋加固的木梁进行了实验研究。此外，本文提出了一个通用的理论模型来估计NSM FRP木梁的抗弯矩。实验研究检查了两种加固结构的白云杉木材标本。一种是仅在受拉区域上带有钢筋的钢筋，另一种在受拉和受压区域上都带有钢筋的钢筋。还包括对照样品以用于比较目的。所有梁的矩形横截面均为70×215 mm，并在跨度为2.3 m的四点弯曲配置下加载。在位移控制准静态单调载荷下测试了总共20个样品。对于NSM FRP增强和未增强的试样，观察到的主要破坏机理是木材在拉伸区的脆性拉伸破坏。讨论了载荷-挠度曲线，应变分布曲线和破坏模式。据观察，由于NSM的增强，木梁的极限载荷（33-69％）和抗弯刚度（22-33％）显着增加。