Determination Shear Cracking Patterns of Fibre Reinforced Concrete

Concrete has been the most widespread construction material in civil engineering and architecture in modern times. Its remarkable compression strength, and the reduced tensile strength and ductility lead to the use of steel bars in the zones where tensile stresses appear. Another option when needing to improve the tensile and bending properties of concrete is achieved through the use of structural fibres such as steel fibres or polymer ones. These fibres added in the correct dosages may be considered as a structural element of the material and consequently the reduction or elimination of steel bars might be enabled. Although literature provides numerous research with respect to the tensile or bending behaviour of fibre reinforced concrete, there are certain aspects that need to be studied regarding the shear behaviour of the material. In this contribution, fibre reinforced concrete (FRC) with steel or polyolefin fibres added in various dosages were tested under a pure shear stress state. Through a digital image correlation system, the cracking patterns of the mixes tested were obtained and the influence of the type and dosage of fibres analysed. In addition, the shear-friction theory when applied to FRC has been discussed.