Numerical Study of Composite Wrapped Reinforced Concrete Columns Subjected to Close-in Blast

A blast or an explosion has become a considerable form of threat to civilian infrastructures worldwide in recent-decades because of their highly dynamic, non-linear and destructive nature. As opposed to conventional loads, the response of RC members to a blast wave is highly erratic as it depends on a lot of factors such as type, shape, orientation and mass of explosive, standoff, ground reflection to mention a few. The damage of an RC member on application of blast pressure is also very severe as it is a combination of flexural and shear deformations, spalling and crushing of concrete etc. For RC columns however, when compared to beams or slabs the situation is more critical since its failure can often result in global structural collapse due to progressive failure. This research article provides a comparative analysis of the effectiveness of various composite wraps in protecting RC Columns against the detrimental effects of blast wave impingement by reduction of peak mid span displacement and subsequently the support rotation of column and reduction in deformation, energy and stresses of concrete and reinforcements. The analysis is performed using the CONWEP approach in LS-DYNA finite element package through which blast loading can be applied by specifying the mass and deflagration co-ordinate and then the CONWEP applies the blast load through a time-varying pressure which is very much similar to a real blast scenario.