In this paper, the following conclusions and summary can be made : 1) An energy absorption of concrete specimen with unit size of (10 × 10 × 10 cm) is examined from the experimental data under triaxial compression, and then a characteristic equation to evaluate energy absorption after failure of concrete is suggested. 2) An energy absorption of concrete specimen with different shapes and sizes is also considered from the experimental data. 3) A length of failure zone inside the concrete specimen with different shape ratio becomes longer with an increase in the confining pressure. 4) An energy absorption capacity per unit volume decreases with an increase in the size ratio of concrete specimen. 5) Applying the results obtained from items 1) through 4), concrete-filled tubular steel columns are analyzed, and analytical results are compared with the experimental data.
