Tensile characterization of high-performance fibre-reinforced concrete: effect of steel or amorphous metallic fibres and of cement type

The need of more sustainable structures pushes ahead the formulation of new advanced cementitious materials which can significantly improve the structural durability, thus resulting into a longer service life with reduced maintenance. Within this framework, the research project ReSHEALience (H2020 GA 760824) has developed a new approach for the design of structures exposed to extremely aggressive environments, starting from a novel concept of High-Performance Fiber-Reinforced Concrete (HPFRC). In a design perspective, this makes it necessary to effectively identify the main parameters describing the overall material behaviour in tension (this being instrumental also for the durability estimation in the cracked state). In the present study, starting from the results of 4-Point Bending Tests on small beams, an inverse-analysis identification procedure has been implemented in order to evaluate the response in direct tension in terms of stress–strain and stress-crack opening laws. The procedure has been implemented for three different HPFRC mixes differing in the type of fibre (straight steel or amorphous metallic ones) and of cement (CEM I or CEM III). The characterization procedure allowed to highlight the effect of fibre type on the whole response in direct tension in terms of loading–unloading response and post-peak regime. In this view, the study aims at further pushing forward the adoption of HPFRC in the design of structures, thanks also to the increasing awareness fostered by the most recent standards.