Response of Ultra-High Performance Fibre Reinforced Concrete Wall Panels to Blast Loading

Abstract

<p>Ultra-High-Performance Fibre Reinforced Concrete (UHP-FRC) is a next-generation concrete with outstanding properties in the fresh and hardened state and superior dynamic properties to traditional concretes. This research focuses on the response of UHP-FRC wall panels under blast loading and presents the advantage of using UHP-FRC over traditional concrete in blast-resistant applications while proposing procedures for the practical analysis and design of UHP-FRC blast protection shields. These objectives are achieved through a two-phased experimental investigation and a comprehensive numerical study.</p> <p> The first phase of the experimental program is conducted at Ryerson University. It includes static four-point load testing on six UHP-FRC one-way panels to investigate the effects of different reinforcement ratios (0%, 1%, and 2%) and fibre volumetric ratios (2% and 3%) on flexural response. The experimental results are used as reference static data for the dynamic shock tube testing. The second phase of the experimental program is conducted at the University of Ottawa using a blast load simulator (shock tube) to investigate the dynamic response of UHP-FRC panels to blast loading. Eight one-way simple supported panels of identical dimensions are tested. The parameters investigated are the steel reinforcement ratio (0%, 1%, and 2%), steel fibre volumetric ratio (2% and 3%), and concrete type (UHP-FRC vs. NSC and HSC). Furthermore, the study provides reference data for the validation of the numerical modelling. The test results showed that UHP-FRC outperformed traditional concrete by showing reduced fragmentation and higher ductility and energy absorption. Experimental results also showed that steel reinforcement is critical to the overall performance of the UHP-FRC panels.</p> <p> The numerical investigation included the development of a new constitutive model suitable for UHP-FRC to be used with the concrete damage plasticity model (CDP) for finite element analysis. The numerical simulations are performed using the ABAQUS/Explicit[1] numerical platform. The model is validated against the experimental data from the current study and other published data from the literature, yielding good results. The developed numerical model is further used to conduct a comprehensive design optimization study on UHP-FRC wall panels. The parametric study provides guidelines for selecting optimum design parameters for UHP-FRC blast protection panels. </p>