Novel steel fibre-reinforced preplaced aggregate concrete with superior mechanical performance

This study pioneers the concept of fibre-reinforced preplaced aggregate concrete through premixing and preplacing steel fibres with aggregates in the formwork, then injecting a flowable grout. Unlike in conventional steel-fibre reinforced concrete where the fibre dosage, length and aspect ratio are hampered by workability considerations, the influence of fibres on workability, place-ability and consolidation is eliminated. Hence, fibre dosages beyond those conceivable in conventionally mixed concrete can be considered. The compressive, tensile and flexural strengths, load-deflection curves and toughness were appraised for the new steel fibre-reinforced preplaced aggregate concrete incorporating various dosages of steel fibres having different lengths. It is shown that the ability of using higher fibre dosages allows achieving exceptional engineering properties for preplaced aggregate concrete. Indeed, the material can easily be produced with steel fibre dosages exceeding 6%, making this innovative, yet simple to produce concrete, a strong contender in many construction applications.