Experimental Study On The Shear Capacity Of Post-installed Anchor Group In Concrete Structures

Chemical anchor is a widely-used post-installed anchorage connection in the fields of strengthening and retrofitting engineering in China. The current study is mostly about behavior of single anchor, while in practice the anchorage system comprises multiple post-installed anchors in complex loading conditions. Based on research achievements of anchorage behavior under shear, experimental study of four chemical anchor group with different spacing and different edge distance are carried out and the behavior of shear capacity and failure mode are explored in this paper. The effect of spacing and edge distance on shear behavior of anchor group is analyzed with ANSYS software. Which includes as follows:(1) The former research achievement on post-installed technology are summarized, as the factors affecting the post-installed anchor include: concrete strength, concrete reinforcement, concrete crack, anchor depth, anchor spacing and edge distance, concrete depth, friction between the steel plate and concrete surface.(2) Experiments on static shear tests of specimens with four chemical anchors are carried out, and failure course, failure mode and shear capacity of chemical anchor group are supervised and measured.(3) Experimental data are analyzed and summarized. The concrete breakout of wedge cone occurs in the specimens with 5d edge distance, with the crack expanding along 35 degree from the former anchors to the concrete free edge, always steel failure is observed in the latter anchors at the same time. Finite element software-ANSYS is used to simulate the behavior of post-installed anchor group under shear. The results are compared with data and phenomena of experiment in loading capacity, failure mode, deformation and displacement.(4) The design of the shear capacity of post-installed anchors all over the world is presented based on the failure modes. The analysis of different design method is compared, and some practical application of the design for shear capacity is put forward at the end of the paper.