Study On The Mechanical Performance Of Post-Installed Stressed Steel Bar

With the increase of the number of building which need to be strengthened and reformed, the technology of chemically planting bar has became a important technical way which is widely used for the structural reinforcement and reform in practical project. So there are significant means in theory and practical project.This paper made a deeply analysis to the mechanical performance of post-installed stressed steel bar by theoretical analysis, experimental verification and numerical simulation. In the theoretical part, introduced bearing capacity constraints on every part of chemically planting bar component, and summarized it is calculation ways of ultimate bearing capacity. Study on shearing force transfer mechanism in new to old concrete interface has been done, and summarized the existing formulas of shear bearing capacity of new to old concrete interface. Chemically planting bar specimen's pull-out test and new to old concrete interface's shearing test have been done, to respectively verify the chemically planting bar component's calculation theory of ultimate tensile bearing capacity and formulas of shear bearing capacity of new to old concrete interface which used planting bar as connectors. At the same time, pull-out test is stimulated numerically by the contacting analysis method of the finite element program ANSYS. Obtained the following conclusions:1,The anchorage depth reach to 15d, which can ensure that planting bar component's ultimate tensile bearing capacity meet the requirement.2,When chemically planting bar component come to ultimate limit state, it can continue to work, but the bearing capacity begin to decrease, so the failture of planting bar component is a ductile failture, which can satisfy the requirements of actual engineering tasks.3,In the new to old concrete interface's shearing theory, the old concrete surface roughness have great influence to component's shear bearing capacity.4,Embedded steel bar's stress distribution is linear in the middle section, stress have a maximum on the edge of orifice, and close to zero in the innermost.5,In the numerical simulation,it is accurate to use contacting analysis method to stimulate the bond-slip of anchoring adhesive between steel bar and concrete.Finnaly genelization of this paper is issued, and proposed the further research direction and methed about chemically planting steel bar.