Response of strengthened unreinforced brick masonry wall with (1) mild steel wire mesh and (2) CFRP wrapping, under close-in blast

Abstract

In the past few decades, the world is experiencing a number of frequent and unanticipated blast explosions. Property loss and casualties caused by these blasts are of great concern to state authorities and are of sufficient interest to the structural engineers and researchers. A common structural member in the buildings used for both commercial and residential formats is load-bearing brick masonry walls. For the safety of a structure, the masonry walls which are more vulnerable against such loadings are required to be strengthened. Many retrofitting techniques to strengthen the masonry walls are in vogue. In the present study, a detailed micro-model of 1600 mm × 2100 mm × 240 mm (length × height × thickness) clay brick unreinforced masonry wall has been developed, analyzed, and validated with the available experiment results, using the ABAQUS/Explicit software under the 5 kg-TNT blast load at scaled distance 0.58 m/kg1/3. The Concrete Damage Plasticity (CDP) model including the strain rate effects is used to model the masonry material behavior to blast loading. To improve the response of the wall, it has been strengthened with (1) mild steel wire mesh of different thicknesses 2.50, 3.50, and 4.50 mm (i) on the rear face only, and (ii) on both the faces of the wall; and (2) carbon fiber-reinforced polymer (CFRP) wrapping (i) 0.50 and 0.60 mm thick on the rear face only, and (ii) 0.30 mm thick on both the faces of the wall. Response of the strengthened walls is discussed and compared. The equivalent thickness of the wrapping to the steel wire mesh from displacement and damage point of view has been evaluated.