Softened Truss Model Theory for the Analysis of Fibre Reinforced Concrete Deep Beams and Corbels - E

Abstract

Reinforced concrete members may be subjected to axial load, bending moment, shear and torsion. However the behaviour of these members under shear or combined shear and torsion is a complex phenomenon. In this study the softened truss model theory is applied for the analysis of fibre reinforced concrete deep beams and corbels. The theory is more promising than the strut and tie model which satisfies the equilibrium conditions and to some extent materials constitutive relationships. While this theory, considers the equilibrium, compatibility, materials constitutive relationships and the degrading effect of the diagonal tension cracks on the compressive strength of cracked reinforced concrete element when subjected to biaxial compression-tension stresses. The previously developed algorithms for the analysis were modified by incorporating the effect of short discrete steel fibres on the behaviour and strength of concrete subjected to shear. Fibre reinforced concrete deep beams and corbels were analyzed using the adopted algorithm and materials constitutive relationships. The predicted effects of the shear span / depth ratio, volume fraction of steel fibres and the longitudinal steel ratio on the shear strength of fibre reinforced concrete deep beams and corbels showed good agreement with published experimental results.

Shear Bearing Capacity of Steel-Fiber-Reinforced Concrete Shear Wall under Low-Cycle Repeated Loading Based on the Softened Strut-and-Tie Model

“…In order to reduce the cost of computation, the random distribution of SF within the three dimensions of the SFRC SW web can be considered equivalent to the arrangement of horizontally and vertically finely distributed steel bars in the SBC analysis of SFRC SWs. Consequently, the cross-sectional area of the horizontally distributed SF tie rod, A h,sf , can be determined by [38]:…”

“…where A sf is the cross-sectional area of a single SF; and n sf is the number of equivalent horizontal SFs, which can be determined by [38]:…”

“…where ρ f is the volume ratio of SF; the equivalent reduction coefficient, denoted as η 2 , can be approximately considered as 0.41, as inferred from the analysis of experimental results reported in the literature [38].…”

Shear Strength Prediction for SFRC Shear Wall with CFST Columns by Softened Strut and Tie Model

“…where ρ sf is the steel fiber volume fraction and η 2 is the equivalent coefficient, which can be approximately designated as 0.41 according to the study in the literature [26]. e sectional area of horizontal steel fibers, A sf,h , can be determined as…”