Blast Testing of Pre-Cast Concrete Load-Bearing Wall Panels

Over the past two decades, blast resistant design of buildings has become increasingly prevalent, with most U.S. Government owned or leased buildings requiring some level of blast resistance. The number of buildings being designed for blast resistance has increased, resulting in precast pre-stressed concrete structural system becoming a common consideration for construction type. The blast response characteristics of some of these systems are not supported by available test data. One such system is load-bearing precast panels. While concrete has long been used for blast resistant construction, including building columns subject to axial load, blast response research on load-bearing concrete wall panels is extremely limited. A research program to gather response data and improve analytical models for load-bearing pre-stressed pre-cast concrete wall panels was funded by the Precast Concrete Institute to provide a better characterization of the blast response of this structural system. This paper will describe the experimental portion of the research program, focusing on the approach used in testing three different wall panel designs in shock tube tests that included static applied axial loading. Discussion will include the apparatus designed for application of the axial load and its capabilities, including changes in axial loading as the test specimens respond to applied blast loads. The axial force provided by the apparatus will also be compared to analytical predictions of axial forces for a building determined from finite element calculations. General effects of the axial load on performance of the panels compared to performance of non-load bearing panels will also be discussed in the paper.