Behavior and punching capacity of flat slabs with the rational use of UHPFRC: NLFEA and analytical predictions

Theoretical model of shear capacity of steel fiber reinforced concrete beams

“…The scope of this work is normal strength SFRC members. It is only briefly explored if tension-stiffening ultra-high performance fiber reinforced concrete (UHPFRC) [12,13] can be addressed with the same model. The shear capacity is derived by summing the contributions of aggregate interlock [14], dowel action [15], capacity in the tension zone [16], and capacity of the uncracked concrete in the compression zone [17], considering the mechanical properties of SFRC [4], the sectional equilibrium of SFRC [18,19], and the effect of fibers on crack width and spacing [20].…”

Nonlinear analysis of flat slab‐column connections to optimize the use of HPFRC under monotonic vertical loading

“…The first one is the lack of guidelines in the current concrete design codes, which are more suited for NSC 14 . Another obstacle is the limited advancement in the development of rational constitutive models and the absence of easily employed finite element (FE) models for calculating fiber‐reinforced concrete (FRC) structural components, as discussed by Zhang et al 15 As a consequence, a few numerical studies related to the application of HPFRC/UHPFRC in flat slab connections can be mentioned 16–18 . Furthermore, the results of blind competitions organized by the fib WG 2.4.1 have shown considerable scatter in the FEM‐based assessment of real‐scale FRC beams and one‐way slabs failing in shear 19 .…”

One-way shear and punching strength of reinforced concrete slabs without transverse reinforcement under concentrated loads

“…In approach 4, the viscosity parameter from approach 3 was reduced to the value of 0.00001, which was demonstrated in other studies as being a value sufficiently low to not change the material behavior in an undesirable way and allow numerical convergence in the processing of the FEM (SOUSA et al, 2021b). Table 7-9 shows that the predicted failure load decreased markedly from approach 3 to approach 4, and most of the prediction failure loads arose on the safe side.…”

“…A large number of studies contributed to predicting the sectional shear capacity of reinforced concrete (RC) beams (RIBEIRO et al, 2020;SANTOS et al, 2019) and the punching capacity of flat slabs or slab-column connections (SOUSA et al, 2021b; GENIKOMSOU; POLAK, 2015) using three-dimensional (3D) non-linear finite element analyses (NLFEA).…”

“…The interface between the support plates and loading plate surface with the slab was modeled assuming (i) hard contact (allowing separation of the surfaces) and (ii) frictionless. A perfect bond between reinforcement and concrete was also assumed based in previous publications (SOUSA et al, 2021b) since no anchorage failure was reported.…”