Combined influence of polymeric and mineral fibres on fresh-state performance and fracture properties of high-performance self-compacting concrete

Abstract

Abstract This study investigates the influence of polyolefin, polypropylene (PP), basalt, and polyvinyl alcohol (PVA) fibres, applied individually and in hybrid systems, on the rheology-related fresh-state behaviour and fracture performance of high-performance self-compacting concrete (HPSCC). Nine concrete mixtures were formulated, including a fibre-free reference and eight reinforced variants with short (12 mm) and long (38 mm) fibres. Fresh-state properties were evaluated using V-funnel, L-box and J-ring tests, while hardened specimens were evaluated for compressive, tensile and flexural strength, as well as fracture energy and crack propagation characteristics. The results demonstrate that the fibre type and geometry significantly affect both workability and mechanical performance. Crimped PP fibres (38 mm) achieved the highest compressive strength (+ 19.9%) and tensile strength (+ 64.8%), while short PVA fibres provided the greatest improvement in flexural strength (+ 122%). The highest fracture energy (~ 1879 J/m²) and post-cracking ductility were obtained for hybrid systems combining long ductile and short stiff fibres (PD38 + PVA12), confirming the effectiveness of multiscale reinforcement. However, enhanced fracture resistance often came at the expense of workability, especially in PVA-rich systems. Future research should address this balance by optimising hybrid ratios and admixture design. The presented dataset provides reproducible results linking fresh-state behaviour with fracture performance and offers guidance for the design of fibre-reinforced HPSCC balancing self-compactability and mechanical resilience.