Assessment of the Shear Behaviour of Fibre Reinforced Concrete Through Numerical Modelling of Shear-Friction Theory

Few published studies have dealt with the mechanisms of reinforcement of fibre reinforced concrete (FRC) when it is subjected to shear stresses. Possibilities for noticeable improvements and steel rebars reduction have been reported although additional research is needed in order to determine and quantify the shear resisting mechanisms of FRC. The significance of this research relies on the use of several types of FRC, previously characterized under flexural tests, to perform push-off tests. The tests were complemented with digital image correlation (DIC) techniques in order to obtain displacements and crack openings that will permit the development of the shear-friction theory adapted to FRC. The experimental campaign was performed with specimens of dimensions 270 º— 150 º— 150 mm3. The specimens were manufactured with six types of concrete: two moderate-strength concrete matrixes with 6 and 7.5 kg/m3 of polyolefin fibres, two medium-strength concrete (vibrated and self-compacted) reinforced with 10 kg/m3 of polyolefin fibres and two steel fibre reinforced concrete types with 50 and 70 kg/m3 of steel hooked fibres. The results showed that FRC follows an analogous behaviour compared with reinforced concrete and the shear-friction theory. The relations between the displacements and the crack openings were achieved as well as deformation maps in the push-off tests. © 2021, RILEM