Abstract:

This study presents a new methodology to evaluate the load carrying capacity of deteriorated nonslender bridge pier columns by construction of the full P-M interaction diagrams. This method uses the actual material properties of deteriorated columns, and accounts for amount of corrosion and exposed bar length, concrete loss, loss of concrete strength due to stirrup deterioration (i.e., loss of confinement), bond failure, and type of stresses in the corroded reinforcement. The developed structural model and the damaged material models are integrated in a spreadsheet for evaluating the load carrying capacity for different deterioration stages and/or corrosion amounts. Structural effects of corrosion on the residual load carrying capacity of reinforced concrete columns are investigated for three equal size columns having different reinforcement ratios, cover to diameter ratios and cover to height ratios and exposed bar lengths by using the developed model. Available experimental and analytical data for the effects of corrosion on short columns subject to axial loads combined with moments (eccentricity induced) are used to verify the accuracy of proposed model. It is observed that for the limited available experimental data the proposed model is conservative and is capable of predicting the load carrying capacity of deteriorated reinforced concrete columns with reasonable accuracy. The proposed analytical method along with results of detailed investigation of deteriorated reinforced concrete columns will improve the understanding of effects of deterioration on structural members, and allow inspectors, and engineers to qualitatively assess load carrying capacity of deteriorated reinforced concrete bridge pier columns.