Analytical Assessment of Blast Resistance of Precast, Prestressed Concrete Components

Protection against blast has become a high priority for many owners of structures. Blast retrofits/structural hardening, as with earthquake retrofits, can be costly. For this reason, it is important to understand that any structural element has an inherent capacity to absorb energy and resist some level of blast demand. A general evaluation that allows a designer to realize the absorption capacity of a structural element may preclude the need for a blast-specific retrofit. To illustrate this concept, blast resistances of non-loadbearing precast, prestressed concrete sandwich wall panels (PCSWP) are examined. These components are extensively used in modern construction for cladding of structural systems and often provide a significant level of protection from blast events. This paper examines the behavior of PCSWP subjected to blast loads. Four explosive experiments were performed on 4 sets of wall panels. An analytical model was developed and validated with the measured blast demands and peak displacements. The analytical model is used to predict wall-panel damage for varying levels of peak pressures and impulses. An extension of this method is proposed for assessing the blast resistance of horizontal diaphragm elements, such as double tees or hollow-core. An example analysis for a double-tee structural base system with a localized blast is provided.