Performance of RCC Column Retrofitted with CFRP Wrappings and the Wrappings with Steel Angle-Batten Jacketing Under Blast Loading

Blasts and accidental explosions are being reported more frequently than before with grievous injuries and loss of lives and damage to the structure, increasing the concern of disaster management authority officials. Structural engineers apprehend that such events may trigger progressive structural collapse leading to huge loss of property and its consequences and therefore the blast performance of important load-carrying members such as columns becomes the topic of interest. Blast performance and blast-resistant design are being given importance for the structure likely to be the target of insurgents by various researchers and engineers. In a framed structure system, the safety of columns being the principal element against blast loading is extremely important for the stability of the structure. The present study focuses on how best can we enhance the blast performance of the reinforced concrete (RC) columns of an existing building. One 3000 mm long, 300 mm × 300 mm RC column carrying an axial load of 950 kN subjected to the 82 kg TNT equivalent blast loading tested experimentally has been first analyzed using the ABAQUS/CAE software. The concrete damage plasticity (CDP) model including the strain rate effect is used to model the concrete material behavior to blast loading. To enhance the performance of the column, (1) CFRP wrappings over the (i) seismic confining regions, (ii) seismic and mid-height regions, and (iii) entire length, and (2) jacketing with steel angles at the corners throughout the column length and connected with battens on the wrappings are considered. Results in terms of displacement, damage, and stresses are compared and discussed. Considered provisions lead to a novel technique of retrofitting the RCC columns with CFRP wrappings with steel angle and batten jacketing over the seismic confining regions and mid-height against blast loading.