F. Cannella

Moment-Axial Domain of Corroded R.C. Columns

In the present paper, a simplified model to determine the moment-axial force domain of the cross-section of reinforced concrete columns subjected to corrosion process is presented. The model considers members with square and rectangular cross-sections and it accounts for cover spalling, buckling of longitudinal reinforcing bars, loss of bond of bar in tension, reduction of confinement pressures (due to the reduction of the area of stirrups and cracking of concrete induced by rust formation). The analytical expressions for prediction of the area reduction of steel, bond strength and critical load of longitudinal bars utilized were verified against experimental data available literature.

Analytical prediction of the flexural response of external RC joints with smooth rebars

An analytical model in a closed form able to reproduce the monotonic flexural response of external R.C. beam-column joints with smooth rebars is presented. The column is subjected to a constant vertical load and the beam to a monotonically increasing lateral force applied at the tip. The model is based on the flexural behavior of the beam and the column determined adopting a concentrated plasticity hinge model including slippage of the main bars of the beam. A simplified bilinear moment-axial force domain is assumed to derive the ultimate moment associated with the design axial force. For the joint a simple continuum model is adopted to predict shear strength and panel distortion. Experimental data given in the literature are utilized to validate the model. Finally, the proposed model can be considered a useful instrument for preliminary static verification of existing external R.C. beam-column joints with smooth rebars.