Strain-hardening Ultra-high Performance Fibre Reinforced Concrete: Deformability versus Strength Optimization

Abstract

High Performance Cement-based composites such as some UHPFRC or SHCC exhibit a tensile strain hardening response associated to the progressive formation of finely distributed microcracks. Strain Hardening (SH) - UHPFRC with suitable fibrous mixes have a dense matrix, a very low capillary absorption of liquids, significant viscoelastic potential and limited shrinkage. They exhibit a tensile strain hardening response up to 0.3 ‰. Strain hardening materials are candidates for improving existing or new structures to increase their durability and mechanical performance. With this aim in view, the impact of macro and microcracking on the protective function and corrosion mechanisms in cementitious materials has to be critically weighed to choose adequate materials in terms of strength and deformability, to fulfil durability requirements. From this basis, the mechanical response (strength, deformability and associated crack formation) can be tailored according to the applications. Finally, future steps for the development and applications of these advanced contemporary materials can be defined.