Masonry Infill Walls Enhanced with the Reinforced Shotcrete in Blast Incidents

Explosions would be categorized as one of the rare loading scenarios for common occupancy type buildings and/or not highly important structures and, eventually being neglected in their design procedure, shall be rather closely attended to in the design of the essential buildings or ones located in the sensitive sites. In this paper, the performance of isolated masonry walls confined within a structural frame and subjected to blast-load perpendicular to the wall face is explored by constructing masonry walls' FE numerical models, and the level of observed damages is set as the controlling criterion. To achieve this goal and to encompass a full range of predefined displacement-based performance levels (associated with the different levels of damage) described by the FEMA code, walls are subjected to low- to high-severity explosions. The masonry walls enhanced with the shotcrete are then numerically investigated with shotcrete positioned at the wall face in front of and back to the explosion source with the aim of evaluating the retrofitted masonry wall performance while exposed to an explosion. The geometrical parameters including the thickness of the shotcrete (5-10 cm) and the amount of reinforcement (0-2.5%) as well as their mechanical properties such as the shotcrete compression strength (25-48 MPa) are altered within the practical range to find out the effects of each parameter on improving the enhanced masonry wall performance through a direct application of the pre-obtained damage index quantities. Accordingly, a step-wise design procedure for the selection of the shotcrete is suggested.