Fracture mechanics of polyolefin fibre reinforced concrete: Study of the influence of the concrete properties, casting procedures, the fibre length and specimen size

Abstract

The final positioning of fibres plays a major role in fibre reinforced concrete (FRC) performance, especially in fracture results used to evaluate the structural competence of the composite material. FRC post-cracking behaviour is related with the number of fibres acting in the cracked surface and the forming angle. This study aims to associate polyolefin fibre orientation and distribution with several external regular and standardised conditions that have been shown to affect steel-rigid fibres positively. The main sources of anisotropy have been addressed: fresh state properties of the concrete, pouring methods, compaction procedures, wall-effects and formwork geometries. The mechanical properties and fracture behaviour showed a remarkably reliable performance of the polyolefin fibre reinforced concrete. While such variations had an equal fibre dosage of 6 kg/m3, the results showed narrow scatter. The fracture surface analysis allowed assessment of the differences, obtaining the orientation factor and evaluating wall effects and fibre distribution with each procedure and concrete type.