Steel reinforced polymer strengthening of reinforced concrete to resist blast loads

The columns of reinforced concrete (RC) buildings are very susceptible to blast loading from close proximity terrorist bombs. When the columns in a multi-story building are targeted, their failure can lead to collapse and catastrophic loss of life. Research sponsored by the U.S. Department of Defense (DoD) has suggested that the retrofitting of RC columns with Fibre Reinforced Polymer (FRP) sheets may be an efficient means of boosting their survivability in an explosion.;The present work was designed to examine the effectiveness of using SRP wraps as a retrofit to increase the blast resistance of RC columns and beams. From the series of tests, it was observed that SRP wraps may change the mode of failure under these circumstances by reducing the occurrence of concrete compression failure at the plastic hinge locations and may improve the survivability of concrete columns. This was particularly significant for the axially loaded element. Whereas for the unwrapped specimen a concrete crushing mode of failure and no residual capacity was observed, a more ductile steel yielding failure was observed for the wrapped specimen that allowed it to remain intact. As well, the durability of the material when subjected to the extreme temperatures and loading conditions found in a blast environment suggests that it may be suitable for use in retrofit projects where close proximity explosions are a concern. (Abstract shortened by UMI.);Steel Reinforced Polymer (SRP) sheets are a recent addition to the market of structural strengthening materials and research suggests that flexural strengthening effects similar to FRP can be achieved at a fraction of the materal cost. The increased toughness and lateral stress resistance of the steel chords found in SRP also make it an ideal candidate for use in the retrofitting of RC members against blast effects.