This paper presents the behavior of hollow concrete cylinders fully- and partially-confined with carbon fiber reinforced polymer (CFRP) sheets. To examine a potential size effect, geometrically similar configurations are considered (diameter to height = 1:2 and inner to outer diameters = 0.75:1.0) with two confining schemes (one-end and both-end wrapping). A total of 72 cylinders are tested, followed by analytical modeling to complement experimental findings. The load-carrying capacity of the cylinders is controlled by the size, CFRP-coverage, and confining methods. The strength of the partially-confined concrete is reliant upon the interaction between the confined and unconfined portions in tandem with stress-restraint zones. Both-end confinement shows better strengthening effects than its one-end counterpart. Three types of failure modes are observed (diagonal tension cracking, local crushing of unconfined concrete, and rupture of CFRP), depending on the degree of CFRP-confinement and wrapping configurations. The unconfined concrete away from the loaded region (40% of the cylinder height) remains undamaged until the strengthened portion fails. The circumferential and radial stresses of the cylinders are influenced by their outer-diameter where the CFRP-concrete interface exists. As the size of the cylinders increases, the failure of the CFRP system is retarded. The core strength of the confined cylinders is uninfluential on the development of radial pressure and the behavior of the CFRP-concrete interface. A design model is proposed for technology transfer.

本文介绍了完全和部分约束碳纤维增强聚合物（CFRP）板的空心混凝土圆柱体的性能。为了检查潜在的尺寸影响，考虑采用两种限制方案（一端和两端包裹）的几何形状相似的配置（直径与高度= 1：2，内径与外径= 0.75：1.0）。总共测试了72个气瓶，然后进行分析建模以补充实验结果。气缸的承载能力由尺寸，CFRP覆盖范围和密闭方法控制。部分承压混凝土的强度取决于承压区域与承压和非承压部分之间的相互作用。两端约束比一端约束显示出更好的加固效果。根据CFRP约束的程度和包裹构造，观察到三种类型的破坏模式（对角张力开裂，未约束混凝土的局部破碎和CFRP破裂）。远离受力区域（圆柱高度的40％）的未约束混凝土保持未损坏，直到加固部分失效为止。圆柱体的圆周应力和径向应力受存在CFRP-混凝土界面的外径的影响。随着汽缸尺寸的增加，CFRP系统的故障得以延迟。密闭圆柱的芯强度对径向压力的发展和CFRP-混凝土界面的行为没有影响。提出了一种技术转让的设计模型。取决于CFRP限制和包裹配置的程度。远离受力区域（圆柱高度的40％）的未约束混凝土保持未损坏，直到加固部分失效为止。圆柱体的圆周应力和径向应力受存在CFRP-混凝土界面的外径的影响。随着汽缸尺寸的增加，CFRP系统的故障得以延迟。密闭圆柱的芯强度对径向压力的发展和CFRP-混凝土界面的行为没有影响。提出了一种技术转让的设计模型。取决于CFRP限制和包裹配置的程度。远离受力区域（圆柱高度的40％）的未约束混凝土保持未损坏，直到加固部分失效为止。圆柱体的圆周应力和径向应力受存在CFRP-混凝土界面的外径的影响。随着汽缸尺寸的增加，CFRP系统的故障得以延迟。密闭圆柱的核心强度对径向压力的发展和CFRP-混凝土界面的行为没有影响。提出了一种技术转让的设计模型。圆柱体的圆周应力和径向应力受存在CFRP-混凝土界面的外径的影响。随着汽缸尺寸的增加，CFRP系统的故障得以延迟。密闭圆柱的核心强度对径向压力的发展和CFRP-混凝土界面的行为没有影响。提出了一种技术转让的设计模型。圆柱体的圆周应力和径向应力受存在CFRP-混凝土界面的外径的影响。随着汽缸尺寸的增加，CFRP系统的故障得以延迟。密闭圆柱的芯强度对径向压力的发展和CFRP-混凝土界面的行为没有影响。提出了一种技术转让的设计模型。