A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Improvement of bond performance between concrete and CFRP bars with optimized additional aluminum ribs anchorage
https://orcid.org/0000-0002-9405-3757
Highlights The applied additional ribs anchorage system was an efficient method to enhance the bond stuffiness and pull-out strength. Additional rib anchorage system was obviously optimized and exhibited a very slight tensile strength loss of CFRP bars. The existence of additional ribs transformed the bond stress transferring mechanism and thus delayed the occurrence of the concrete splitting. Empirical expression in ultimate tensile stress that considers the influence of bond length was proposed.
Abstract 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.
Improvement of bond performance between concrete and CFRP bars with optimized additional aluminum ribs anchorage
https://orcid.org/0000-0002-9405-3757
Highlights The applied additional ribs anchorage system was an efficient method to enhance the bond stuffiness and pull-out strength. Additional rib anchorage system was obviously optimized and exhibited a very slight tensile strength loss of CFRP bars. The existence of additional ribs transformed the bond stress transferring mechanism and thus delayed the occurrence of the concrete splitting. Empirical expression in ultimate tensile stress that considers the influence of bond length was proposed.
Abstract 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.
Improvement of bond performance between concrete and CFRP bars with optimized additional aluminum ribs anchorage
https://orcid.org/0000-0002-9405-3757
Highlights The applied additional ribs anchorage system was an efficient method to enhance the bond stuffiness and pull-out strength. Additional rib anchorage system was obviously optimized and exhibited a very slight tensile strength loss of CFRP bars. The existence of additional ribs transformed the bond stress transferring mechanism and thus delayed the occurrence of the concrete splitting. Empirical expression in ultimate tensile stress that considers the influence of bond length was proposed.
Abstract 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.
Improvement of bond performance between concrete and CFRP bars with optimized additional aluminum ribs anchorage
Zhang, Bai (author) / Zhu, Hong (author) / Wu, Gang (author) / Wang, Qiang (author) / Li, Ting (author)
2020-01-02
Article (Journal)
Electronic Resource
English
Bond Properties of Additional Anchorage Schemes for a CFRP Plate-Concrete Externally Bonded System
| Online Contents | 2017