KEY PARAMETERS FOR THE DEVELOPMENT OF AN INVERSE ANALYSIS METHOD FOR CHARACTERIZING UHPC TENSILE BEHAVIOUR

Designing structures with UHPC requires a thorough understanding of its tensile behaviour. Direct tensile tests provide valuable insights but require specialized equipment available in limited number of research laboratories. Bending tests are more accessible and several inverse analysis methods were developed to estimate UHPC tensile properties. However, each method was developed and validated for specific testing configurations. The inclusion of UHPC in CSA A23.1 and S6 (2019) prompted the adoption of European inverse analysis methods for North American bending tests, with limited success without adequate calibration. This provision was removed in 2025 leaving CSA S6 (2025) without a model for determining UHPC tensile behaviour from bending tests. This paper addresses this gap by proposing a simplified methodology that adapts an existing inverse analysis to alternative testing configurations, enables direct calculation of strain hardening UHPC pre peak tensile properties, and improves the reproduction of experimental tensile behaviour observed in 5 UHPC mixtures.