STRUCTURAL BEHAVIOR OF NON-DUCTILE REINFORCED CONCRETE COLUMNS

Abstract

Confinement of columns with non-seismic detailing is prevalent in many old buildings and
common in current detailing practice in many developing countries. This type of columns is believed to have
a very low drift capacity from a conventional design perspective. To investigate the lateral load-drift behavior
and the collapse mechanism of such columns, the experimental tests on four lightly reinforced concrete
columns with light transverse reinforcement ratio have been undertaken. The quasi-static tests were applied on
concrete columns with various longitudinal reinforcement ratio, transverse reinforcement ratio, and lap splice
position. Interestingly, the results showed that the total drift capacities could reach up to 7% well beyond the
required maximum drift suggested by many codes despite the low detailing. Reasonably, the closer the stirrups
spacing, the higher the ductility of the columns. Whereas, it appeared that the higher the longitudinal
reinforcement ratio, the lower the ductility ratio. Furthermore, the theoretical analyses have been conducted to
estimate the lateral load-deflection behavior of the columns which were in a good agreement with the test
results.