TRIAXIAL COMPRESSIVE STRENGTH OF CORE CONCRETE HEAVILY CONFINED BY VIRTUE OF TIE BARSAND STEEL PIPE AND EVALUATION OF LOAD-CARRYING CAPACITY OF RC COLUMN

摘要

The reinforcement and repairing works for the earthquake-proof concerning the bridge piers have been carrying out actively since the Hyogo-Nanbu earthquake. This paper deals with the analysis of steel pipe deformation characteristic and the effectiveness of confined effect in order to look for the basic design concepts for strengthening reinforced concrete column; so, two kinds of the non-loaded sound concrete cylinder and the internally damaged one loaded adjacently before the ante-peak were reinforced by the steel-pipes and then were loaded under compression. The effects of the physical properties of the fillers injected between the steel-pipe and the concrete cylinder on the deformation and the rehabilitation were verified both experimentally. The relationship between the tri-axially, perfectly confined concrete strength according to the decrease of pitch width of tie bars of the RC column and the compressive load-carrying capacity of the steel pipe concrete column has been discussed and further formularized comprehensively, and proposed the compressive load-carrying capacity equation for the reinforcing column model considering the tri-axial confinement strength ratio.