Structural Behavior Investigation of Reinforced Concrete Tapered Solid and Hollow Section Columns under Axial Load

Abstract

 This study involves taking eight models of reinforced concrete tapered columns section where the dimensions of the base at the bottom (da=200 mm) and at other end (db=150 mm) and side depth of (d=200 mm) while the total length (1000 mm).The main variable were taken the longitudinal and ties reinforcing ratio and section type (solid or Hollow) and hollow ratio. All specimens were simple support under influence of axial load to see the effect of these variables on strength and behavior of columns. All columns were classified as short due to slenderness ratio equal to (15.78) less than (22) according to ACI code. Test results gives, the strength capacity of Specimens increased by about (25%) where increased the longitudinal reinforcing ratio to 50% and decreased in corresponding lateral displacement by about (30%), also the ties reinforcing gives same trend but by about (12%) increasing in susceptibility endurance and decrease in lateral displacement by 20% at the mid and quarter upper slim of columns and simple attribution. The hollow section of columns have (recess) effect on columns behavior by reduced ultimate load capacity about (22-37%) and increased in lateral displacement by about (18-35%) for same of applied load compare with solid section. Also the increasing hollow ratio (16 to 41%) led to reduce in load capacity about (13-16%) and increased lateral displacement about (10-14%) with kept other properties constant of specimens. Patterns of failure was exfoliated in the concrete and an increase cracks numbers of the upper slim parts of specimens.