10.46243/jst.2023.v8.i03.pp17-24 registered

This investigation experimentally studies the behaviour of reinforced concrete columns strengthened using reinforced concrete and geopolymer concrete jacketing by subjecting them to axial loading. The experimental results were analytically validated by the finite element model. For this work, six columns of M25-grade conventional concrete were subjected to more than 75% of the ultimate load, after which three columns were jacketed using M40-grade reinforced concrete and another three columns were jacketed using M40-grade geopolymer concrete. The interfacial behaviour of the conventional reinforced concrete column and jacketed geopolymer concrete columns was studied and compared. A three-dimensional linear finite element model was employed to measure the effect of conventional reinforced concrete and geopolymer concrete-jacketed columns under increasing load by considering the concrete damage plasticity and elastoplastic models with isotropic hardening, with validation against the experimental results confirming 90% accuracy of the analytical model. Test results indicated a 15% increase in axial load-carrying capacity compared to control columns, and that repairing similar reinforced concrete columns of square cross section preloaded up to failure with the same jacket restored almost the original load-carrying capacity and stiffness of control columns. The strengthened and repaired columns failed in a ductile manner, whereas repaired failed columns showed a significant loss in ductility due to the existence of cracks in failed columns.