In cases of concrete specimens strengthened by section enlargement, much researches have been concerned with only axial strength on specimens of which inner and outer sections were cast with same strength concrete, but on specimens of which inner and outer sections were cast with different strength concretes have not been carried out in depth.
The objective of this study is to investigate the axial strength of concrete specimens strengthened by section enlargement.
Twenty-four specimens were manufactured and tested to investigate the effect of difference of strength, Poisson‘s ratio and stress-strain curve between inner and outer section concretes, the effect of size difference of specimens on axial strength of specimens strengthened by section enlargement.
The results obtained from test and analysis showed that the axial strength of specimens had been greatly influenced by the effect of Poisson`s ratio and stress-strain curve between inner and outer section concretes. An approach method to predict for axial strength of concrete strengthened by section enlargement was suggested and parameter used in suggested approach method was concrete strength in standard size concrete specimen.
