コンクリート構造物の耐震補強の接合部に適用する円柱状シアキーの提案と耐力式の構築

Abstract

In the seismic retrofitting of an existing concrete structure, the surface of the structural frame is chipped to improve the integrity between the existing frame and retrofitting member. But, quantitatively evaluating strength of these joints are difficult because the concavo-convex shape is influenced by construction worker. Therefore, the authors developed a new joint referred to as the cylindrical shear-key. The cylindrical shear-key is made by filling a cylindrical core on the concrete surface with grouting mortar or concrete, and resists shear forces as a shear-key. Creating a uniform shape is expected to enable quantitative strength evaluation. In this study, direct shear tests were conducted using a cylindrical shear-key to investigate the fundamental performance of the shear-key. Then, based on the test results, an equation was developed for evaluating the strength of cylindrical shear key, and it was shown that the maximum strength could be quantitatively evaluated accurately. And cylindrical shear-key is can contribute to the progression of seismic retrofitting.

Development of Post-installed Headed Bars Embedded into Grouted Holes with Enlarged Ends

“…(3) when bond interface conditions are improved or confining is provided, as in the case carried out by Peng et al (2021) on slanted interfaces, Fc: concrete compressive strength [note that the unit of Fc in Eq. ( 3) is N/mm 2 ], τg: grout shear strength [a lower limit formulation is considered based on the test results of Abe et al (2017) for non-confined grout, whereas the enlarged grout part of the proposed anchor system is actually confined. As confined grout performs better toward shear, as shown by the work carried out by Chen et al (2018), the grout shear strength Eq.…”