Abstract
This study describes a three-dimensional material nonlinear finite element model suitable for
the analysis of high strength reinforced concrete slabs under different states of loading. The
twenty-node isoparametric brick element has been used to model the concrete while reinforcing
steel bars have been idealized as axial members embedded within the brick elements. The
behavior of concrete in compression is simulated by an elasto-plastic work hardening model
followed by a perfectly plastic response, which is terminated at the onset of crushing. In
tension, a smeared crack model with fixed orthogonal cracks has been used with the inclusion
of models for the retained post-cracking tensile stress and for the reduced shear modulus. Three
high strength reinforced concrete slabs and one normal strength concrete slab have been
analyzed in the present study with different boundary conditions and loading arrangements.
Parametric studies have been carried out to investigate the effect of some important finite
element and material parameters. These parameters include the compressive strength of
concrete, amount of reinforcement and slab thickness. The finite element analysis indicated that
when the concrete compressive strength of the slab is increased from (35 MPa) to (80 MPa) an
increase in the ultimate capacity of about (60%) has been achieved. In general good agreement
between the finite element solutions and the available experimental results have been obtained
