Fiber Reinforced Polymer (FRP) composites in the form of laminates and fabrics are installed on reinforced concrete members, using externally bonded (EB) techniques for strengthening. However, the utilisation of capacity of FRP composites is limited due to debonding observed in the strengthening system, due to FRP and concrete interfacial shear stress. Carbon fiber reinforced polymer (CFRP), in a new form of strand sheets were recently developed and have not been adequately investigated upon. These strands are less than 1.0 mm in diameter is woven with thread to obtain the desired width of the sheet. Such strand sheets are likely to have enhanced bond strengths due to the gaps between the strands that increase the surface available for bonding with the adhesive compared to laminates. This paper presents details of an experimental investigation of the influence of CFRP strand sheets on the flexural performance of CFRP strengthened reinforced concrete (RC) beams. In the experimental study, RC beams strengthened with CFRP strand sheets and lami-nates, were tested under four-point bending and compared with an un-strengthened specimen. The main parameter varied was the elastic modulus of the CFRP strand sheet and width ratio (w_f /b) of high strength CFRP strand sheets. The relative contribution of the CFRP strand sheets to the bending moment capacity was observed to be significantly higher than that in the case of the CFRP laminate. The failure mode was observed to change from debonding to concrete cover separation with an increase in width ratio. The rupture was observed as the failure mode in the specimens strengthened with high modulus CFRP strand sheets. As a result, an increase in the bending-moment capacity and ductility of the beams was also observed. Based on the observed failure modes, models for predicting the mechanical behaviour of various systems were assessed.

使用外部粘结（EB）技术将层压板和织物形式的纤维增强聚合物（FRP）复合材料安装在钢筋混凝土构件上。但是，由于在FRP和混凝土界面剪切应力的作用下，在增强体系中观察到脱粘，因此FRP复合材料的产能利用率受到限制。碳纤维增强聚合物（CFRP），以一种新形式的线束片材被开发出来，尚未进行充分的研究。这些线的直径小于1.0mm，用线编织以获得所需的片材宽度。由于股线之间的间隙与层压板相比增加了可用于与粘合剂粘结的表面，因此这种股线片可能具有增强的粘结强度。本文详细介绍了CFRP绞合板对CFRP增强钢筋混凝土（RC）梁抗弯性能影响的实验研究细节。在实验研究中，用CFRP绞合薄板和层压板加固的RC梁在四点弯曲下进行了测试，并与未加强的试样进行了比较。变化的主要参数是CFRP股片材的弹性模量和宽度比（w _f / b）高强度CFRP绞合板。观察到CFRP股片材对弯矩能力的相对贡献明显高于CFRP层压板的情况。随着宽度比的增加，观察到破坏模式从脱粘变为混凝土覆盖层分离。随着高模量CFRP股板加强了试样的破坏模式，观察到了断裂。结果，还观察到梁的弯矩容量和延展性增加。基于观察到的故障模式，评估了用于预测各种系统的机械行为的模型。