This paper computationally investigated behavior of metal sheet confined concrete specimens subjected to axial compression. To understand mechanisms that occurred in the metal sheet confinement system during the loading, plain concrete specimens confined with 1-3 layers of metal sheet were analyzed via the three dimensional finite element analysis. Cylindrical and square cuboid concrete specimens of the same cross sectional area were selected to understand effect of specimen shapes on axial compression behavior of metal sheet confined specimens. The numerical results showed that the metal sheet confinement system could improve axial compression capacity of all the specimens. The improved stress-strain behavior of the specimens was not influenced by lateral confinement only, but also by ability of metal sheet in resisting axial compression. It was observed that shape and number of layers of confinement affected the strength increase. For two layers of metal sheet application, slightly different behaviors were found at the inner and the outer jackets. For the cuboid specimen, different behaviors at the region near the corner and on the side were noticed. The non-uniform stress distribution across the square section led to lower axial strength improvement when applying the same number of metal sheet layers, as compared to the circular section.
Keywords
concrete, metal sheet, axial compression, finite element analysis, confinement.