Strength and fracture energy characteristics of self-consolidating concrete incorporating polyvinyl alcohol, steel and hybrid fibres

Fibre-reinforced self-consolidating concrete (FRSCC) combines the advantages of self-consolidating concrete (SCC) and fibre-reinforced concrete (FRC). In this study, 18 concrete mixtures were developed by incorporating different volumes of polyvinyl alcohol (PVA) and metallic fibres to a maximum of 0.3% by volume. Fresh, mechanical and durability (in terms of chloride penetration resistance) properties of all FRSCC mixtures were evaluated. The influence of fibre type/size/dosage and combination (used in hybrid mixes) on fresh properties (slump flow, L-box passing ability, V-funnel flow time and segregation index) and hardened properties (fracture energy and compressive/flexural/splitting tensile strength) were critically analyzed to study the performance of the FRSCC mixtures. The fibres – metallic ones in particular – were more effective in increasing the fracture energy of FRSCC than in increasing its compressive/splitting tensile/flexural strength. A substantial fracture energy gain of about 507% was observed compared to a 10% increase in compressive strength, a 39% gain in splitting tensile strength and a 124% increase in flexural strength. The improved strength and fracture energy of such FRSCC mixtures can significantly reduce the amount of tensile reinforcement required and substantially increase the energy-absorbing capacity of concrete structures.