محمدرضا ماهینی

Increasing concerns about terrorist attacks and the possibility of accidental explosions in or close to the buildings has increased demands for assessment and retrofit of structural elements against blast loads. In order to avoid hazards and expenses included in the real blast tests, numerical simulation has found to be an efficient alternative for investigation of structures exposed to blast loads, provided that the material model is properly selected and correctly calibrated. In the context of structural failure due to blast loads, concrete structures are more likely to be in danger as a consequence of concrete brittleness. As a remedy to this shortcoming, several fiber reinforced and composite concrete materials have been proposed and successfully verified in diverse technological environments. Among these new generations of enhanced concrete materials, Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) possesses remarkable tensile strength, and its reasonable ductility and significant ability in energy dissipation prior to failure, has been sufficiently encouraging for researchers to examine performance of such material in blast resistant columns. Herein some reported real blast tests on UHPFRC coulmns are simulated using ABAQUS, adopting suitable damageplasticity model for the UHPFRC material. Computed responses for weak and strong explosions nearby the columns has been found in good agreement with the real blast test results. Ability of the developed model in prediction of the real responses, reveals validity and reliability of the simulation for further numerical and parameter analyses. It was observed that the maximum displacement of a model is only 25 millimeters and about 60% will be reduced to non-resistant ones, When it is used with the UHPC jacket for the retrofitting of RC columns. Also, by introducing a pressure-impulse diagram for assessing damage to the column, blast resistance capacity of the column against the contact and far explosions inc