LAUSR

Abstract Ultra-high performance concrete (UHPC) is proven to provide superior performance, in terms of both strength and durability, compared to conventional concrete. While the response characteristics of UHPC have been extensively explored under conventional loads, there is a gap in the literature concerning how UHPC can be employed as a protective system against windborne debris impact. This is of particular interest because windborne debris has been the primary source of damage to building envelopes during extreme wind events. To investigate the performance of UHPC wall panels subjected to windborne debris impact, a set of high-fidelity finite-element models were developed in the current study. Upon validating the models using the experimental test data, numerical simulations were conducted to assess the performance of a variety of UHPC wall panels under windborne debris impact. The UHPC wall panels under consideration had a wide range of thicknesses, i.e., from 76.2 mm to 203.2 mm, and were modeled both without and with embedded steel rebars. As for impact scenarios, both lumber and pipe projectiles were considered with a range of velocities, spanning from 10.0 m/s to 70.0 m/s. This holistic matrix of simulations helped characterize various response measures, including the type and extent of damage to the UHPC wall panels individually and in comparison to their normal-strength concrete (NSC) counterparts. The investigations were then extended to evaluate the UHPC and NSC wall panels under a set of pass/fail criteria prescribed by the relevant codes and standards for basic and enhanced protection wall systems. The wealth of data generated through this study was finally employed to develop a set of closed-form equations for predicting the mean impact force that the UHPC wall panels are expected to experience, given the mass and velocity of the debris object. This is expected to facilitate the design of this emerging category of wall panels, especially in the regions that witness a high risk of windborne debris impact.