Seismic behavior of reinforced concrete columns with lightly transverse reinforcement

Reinforced concrete columns which are designed on non-seismic details have been known to be vulnerable to shear failure during earthquakes. The axial loads that arise from a combination of framing action of multiple column system and vertical ground motion experience a considerable change which consequently produces complex column behaviour as compared to column under constant load action. Shear degradation of a reinforced concrete column leads to a reduction in axial strength of the column. This in turn causes the design capacity of the reinforced concrete column to be lowered and excess gravitational load will be transferred to neighbouring structural elements. This causes structural instability and propagation of collapse due to the unbalanced state of structural elements. The experimental results gathered showed the effect of varying the axial load on the column behaviour. There is similarity to the crack and failure pattern. The tested specimens recorded different maximum shear capacity and stiffness bahavior. The rectangular column cross section tested at the major modulus of elasticity showed higher shear capacity and ductility as compared to other experimental researches which focuses on square column. Past experimental researches aim to recognize the risk of column shear failure, this allows future engineers to evaluate existing and design new buildings capacity with considerations of seismic effects aimed specifically to avoid column failure. The uncertainties that are present in current shear strength models need to be verified and tested to fully determine the reliability of its uses. Therefore, this research will focus on the mechanism of the axial strength degradation of non-seismically detailed columns under reverse seismic loadings. The tests were designed to observe the behaviour of these columns. The final data gathered analyzed, will provide information on shear strength, Displacement Composition and its overall stiffness behaviour.Bachelor of Engineering (Civil