The slippage of fiber-reinforced polymer (FRP) bars in concrete occurs frequently because of the insufficient anchorage capacity of FRP bars in concrete, and it considerably affects the reliable application of FRP bars as reinforcing steel bars in civil engineering structures, especially in prestressed structures. In this paper, an optimized additional rib (AR) anchorage system was applied to the carbon-FRP (CFRP) bars to improve this weak anchorage characteristic of CFRP bars. The extrusion technology of the additional ribs was optimized, and only a slight deterioration of approximately 1.85% in the tensile strength of the CFRP bars was noted, compared to that corresponding to our previous extrusion technology (a loss of approximately 7.84%). Subsequently, pull-out tests were performed to investigate the influence of the number of additional ribs and bond length on the bond performance between the CFRP bars and concrete. The experimental results demonstrated that the existence of additional ribs, which produced an end pressure, transformed the bond stress transferring mechanism and reduced the radial force exerted on the surrounding concrete, thereby delaying the occurrence of the concrete splitting failure. In addition, the CFRP bars anchored with the additional ribs exhibited a remarkable enhancement in the pull-out strength, whereas this improvement was influenced by the embedment length of the CFRP bars and the ratio of the additional rib length to the bond length (l_ar/L). Finally, an empirical expression to calculate the development length of the CFRP bars with and without an AR anchorage was proposed and compared with the expressions provided in the existing design standards. It was concluded that the applied AR anchorage system could effectively reduce the development length of the CFRP bars. Compared to that of the control specimens, there was approximately 16.7% decrease in the development length for the specimens anchored with one additional rib.

由于FRP钢筋在混凝土中的锚固能力不足，因此经常会在混凝土中发生滑移，这极大地影响了FRP钢筋作为土木工程结构中钢筋的可靠应用，特别是在预应力结构中。在本文中，将优化的附加肋筋（AR）锚固系统应用于碳FRP（CFRP）钢筋，以改善CFRP钢筋的这种弱锚固特性。优化了附加肋的挤压技术，与之前的挤压技术相比，CFRP筋的拉伸强度仅略微下降了约1.85％（损失约7.84％）。后来，进行了拉拔试验，以研究附加肋的数量和粘结长度对CFRP筋和混凝土之间粘结性能的影响。实验结果表明，附加肋骨的存在会产生最终压力，改变了粘结应力的传递机理，并减小了施加在周围混凝土上的径向力，从而延迟了混凝土劈裂破坏的发生。此外，锚固有附加肋的CFRP筋条的拉拔强度显着提高，而这种改进受到CFRP筋的埋入长度和附加筋长与粘结长度之比的影响（实验结果表明，附加肋骨的存在会产生最终压力，改变了粘结应力的传递机理，并减小了施加在周围混凝土上的径向力，从而延迟了混凝土劈裂破坏的发生。此外，锚固有附加肋的CFRP筋条的拉拔强度显着提高，而这种改进受到CFRP筋的埋入长度和附加筋长与粘结长度之比的影响（实验结果表明，附加肋骨的存在会产生最终压力，改变了粘结应力的传递机制，并减小了施加在周围混凝土上的径向力，从而延迟了混凝土劈裂破坏的发生。此外，锚固有附加肋的CFRP筋条的拉拔强度显着提高，而这种改进受到CFRP筋的埋入长度和附加筋长与粘结长度之比的影响（l _ar / L）。最后，提出了经验表达式来计算带有和不带有AR锚固的CFRP钢筋的发展长度，并将其与现有设计标准中提供的表达式进行比较。结论是，应用的AR锚固系统可以有效地减少CFRP钢筋的发展长度。与对照样品相比，锚定有一条附加肋骨的样品的发育长度减少了约16.7％。