Structural performance of RC columns retrofitted with steel-reinforced grout jackets under combined axial and lateral loading

The effectiveness of steel-reinforced grout (SRG) jacketing in improving the structural performance of deficient reinforced concrete (RC) columns is experimentally investigated in this study. Four full-scale cantilever columns were designed following the old construction practice (pre-1970s) in southern Europe. Due to lack of adequate seismic detailing, the columns were susceptible to buckling failure when subjected to combined axial loading and cyclic lateral displacement reversals, simulating seismic loading. Three alternative SRG jacketing configurations were applied differing in the number of layers and density of the Ultra High Tensile Strength Steel (UHTSS) textile. The test results demonstrated the efficiency of SRG jacketing to modify the response of the columns with poor detailing from brittle to ductile by substantially improving their overall structural performance. Finally, code formulations were used to assess the performance of the SRG jacketed columns.