Synergistic Action of Short and Continuous Fibres in Mineral-Bonded Hybrid Protective Composites

The development of novel, cost-effective and highly-optimised construction materials to protect existing infrastructure against extreme loads in a sustainable and affordable way is crucial for the transformation of the construction sector. In this context, fibre and textile reinforced cement-based composites offer attractive solutions. Although Textile Reinforced Concrete (TRC) is emerging as a promising technology, the use of a brittle matrix still raises major concerns, particularly in terms of impact resistance in combination with fire. This paper investigates the mechanical behaviour of hybrid cementitious composites, in which high-tenacity textile plies are embedded in fibre-reinforced matrices with additional ductility resources. The tensile properties of such hybrid solutions are assessed by quasi-static testing. It is shown that short fibres lead to damage smearing by multiple cracking and optimal exploitation of the strength of the textile. More remarkably, this damage smearing plays a critical role under impact and blast scenarios by dissipating considerable amounts of mechanical energy and favouring the strengthening action of the textile, which underlies a promising application potential as an externally bonded protection for critical concrete members to enhance robustness and resilience. Some examples from recent research are presented to illustrate how fibres and textiles work synergistically in hybrid composites for structural protection.