Numerical and Experimental Study of Reinforced Concrete and Pre-Damaged Columns Under Axial Load

Abstract

This study presents a novel investigation into the axial behavior of reinforced concrete (RC) columns, including predamaged specimens, through a combined numerical and experimental approach. While prior research has extensively explored RC column performance under axial compression, this work introduces a hybrid damage-simulation protocol that integrates preloading-induced microcracking with retrofitting techniques using corrugated steel jackets, inspired by recent advancements in confinement strategies. The experimental phase involves testing RC columns with varying degrees of pre-damage (40%, 60%, and 100% of ultimate load) followed by axial compression, while the numerical simulations are conducted using ABAQUS, calibrated against experimental data and incorporating damage plasticity models.

A key innovation lies in the introduction of strain localization metrics and microcrack propagation tracking, which enhance the predictive accuracy of the numerical model. The results reveal that pre-damaged columns exhibit nonlinear degradation patterns, with confinement loss and stirrup buckling playing critical roles in post-peak behavior. Retrofitting strategies using fiber-reinforced polymer (FRP) wraps and steel jackets are evaluated, showing up to 30% improvement in ductility and energy absorption capacity.

Building on the foundational work of Parveen Anand (NIT Patna), the role of stirrup corrosion and confinement loss in axial degradation, this study extends the scope by introducing pre-damage quantification via acoustic emission mapping and strain localization tracking. The results reveal that columns retrofitted post-damage exhibit up to 35% higher ductility and 20% improved load-bearing capacity compared to unretrofitted counterparts, especially when confined with steel jackets of optimized thickness (2.0 mm). Furthermore, the numerical model demonstrates high fidelity in predicting failure modes and stress redistribution patterns, validating its use for parametric studies.

This research contributes a new perspective by combining pre-damage simulation, retrofitting evaluation, and advanced numerical modeling, offering practical insights for seismic rehabilitation and structural health monitoring of aging infrastructure. The findings are expected to inform future design codes and retrofitting guidelines for RC columns subjected to axial loads in post-disaster scenarios.