Behavior of High Strength Reinforced Concrete Hollow Circular Short Columns under Axial Loads

Abstract

This work deals with investigating the capacity of highstrength columns, under axial compression loads. A total ofnine circular column with 600 mm length and 150 mm outerdiameter were tested, three of them were solid as a reference,the remaining six columns were with internal hole of 50 and75 mm dimeter. The effect of hole size as well as area oflongitudinal steel reinforcement was studied. Area of steelused where 0, 301 and 471 mm2and two hole size were 50and 75 mm. The results showed that the increasing oflongitudinal reinforcement ratio from 0 % (plain) to 2.67%(steel reinforcement area of 471 mm2) for solid column causean increase in the ultimate strength by 33.6%, while forhollow columns with 75 mm internal hole the ultimatestrength increased up to 33.2 %. Increase in hole dimeterfrom 50 to 75 mm caused a reduction of columns capacity inall cause, the decrease was up 33 % for columns with 301mm2steel area was up to 32 %, for columns with 417 mm2.