Proposed Flexural Test Method and Associated Inverse Analysis for Ultra-High-Performance Fiber-Reinforced Concrete

The tensile stress-strain response of ultra-high-performance fiber-reinforced concrete (UHPFRC) is a fundamental constitutive property, and reliable knowledge of this response is necessary for appropriate application of the tensile-carrying capacity of such advanced cement-based materials. Flexural test methods whose implementation is well-established present a test procedure capable of assessing this property. Nevertheless, these methods provide indirect information and need to be complemented by inverse analysis to quantify the intrinsic tensile behavior of tested materials. Moreover, bias or scatter can be induced when simplified constitutive laws are assumed for the analysis. Flexural tests were completed on multiple types of commercially available UHPFRC. Relying on direct strain measurements, a new inverse analysis method is presented and qualified, compared with an existing simplified method, and also compared with results from direct tensile tests (DTTs). The advantages and limitations of the experimental and analysis methods were derived.