On the crack opening in textile reinforced concrete with regard to fibre bridging: Fid-Bau Portal

On the crack opening in textile reinforced concrete with regard to fibre bridging

Bayer, D. / Richter, M.

In the presented paper the effect of fibre bridging on the crack face displacement of cracks in textile reinforced concrete is studied. Based on the assumptions of linear elastic fracture mechanics and the principle of superposition, an analytical solvable model for the determination of the influence of continuous fibres on the crack opening displacement in fibre reinforced concrete under mixed-mode loading conditions is developed. The developed approach is based on the weight function method, whereas fibres are regarded by means of discrete crack bridging stresses. One advantage of this analytical approximation is a better understanding of fibre bridging crack mechanisms and the resulting influence on the macroscopic mechanical behaviour of cracked fibre reinforced materials. Parametric variations for studying the influence of geometrical or elastic quantities can be done easily as shown in the previous section. The results of the presented analytical model have been verified by means of the finite element simulation. One of the main current intended application areas is the development of a traction-separation law for cohesive elements appropriate for modelling the fracture process zone of quasi-ductile materials. Therefore, the presented model shall effectively enable the simulation of macrocrack propagation with particular consideration of the specific bond behaviour between roving and matrix. At present stage no suitable criteria for crack propagation in a cementitious matrix was formulated. Additionally, for the simulation of fibre bridging under mixed-mode loading conditions the pullout of inclined fibres from concrete matrix has to be investigated in a more detailed manner.