PERFORMANCE OF FERROCEMENT ANGLE TO RETROFIT THE PARTIALLY DAMAGED RC COLUMN

Abstract

Reinforced concrete (RC) columns are the most crucial building component in concrete buildings, resisting both gravity and lateral loads. Therefore, their effective retrofitting technique is a burning topic in the scientific community. This research investigates the performance of prefabricated ferrocement angles (PFAs) as a retrofitting solution for damaged RC columns. A total of 18 scaled-down square columns of three different concrete strengths of 36.40 MPa, 34.20 MPa and 31.40 MPa were experimentally investigated. The strength of the ferrocement used to make the PFAs was 39 MPa. Each concrete strength group consists of 6 columns: 1 control, 1 control pre-cracked, 2 retrofitted with single-layer wire mesh PFAs and 2 retrofitted with double-layer wire mesh PFAs. The complete retrofitting procedures involved the external application of PFAs at the column corners with bonding agents, joining the PFAs with each other by sewing wire meshes and filling the voids between PFAs with high-strength mortar. The specimens were tested under displacement-controlled axial loading and performance in regard to ultimate load capacity, stiffness, energy absorption, ductility and failure patterns were evaluated.

The application of PFAs significantly increased the axial load capacity of the pre- cracked RC columns. Increasing the layer of wire mesh also increased the gain of

axial load capacity by almost 50%. This increase was found to be more for RC columns of the higher concrete strength group, indicating the dependence of the axial load capacity increase after PFA jacketing on the actual concrete strength of

the RC columns. PFA jacketing also helped to retain the stiffness of the pre- cracked samples while allowing greater lateral and axial deformation. Jacketing

the pre-cracked columns with PFAs increased their energy absorption capacity by more than 100%. The proposed jacketing method of RC columns with PFAs

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also improved their ductility via the confinement effect, ensuring higher plastic deformation and preventing brittle failure.