SPECIFIC BENDING STIFFNESS COMPARISON OF SPHERICALLY VOIDED BIAXIAL CONCRETE SLABS AND SOLID SLABS

Abstract

Spherically hollow or voided biaxial concrete slab (SVBS) configurations that implement empty composite balls as a filling material are gaining momentum due to the reduction in mass-to-capacity and mass-to-stiffness fractions. The SVBS configuration depends on taking out the ineffective concrete mass near the mid-section of a floor in which bending stress is less. This will in turn dramatically reduce the overall structural dead weight. This paper presents comparison of normalized bending stiffnesses for a representative spherically voided biaxial concrete slab with its counterpart solid slab. A representative SVBS element is chosen for capturing the volume action (RVE). The RVE is the primary sub-unit that is periodic and it is modeled in finite element software to determine the stiffness values noting that the SVBS is macroscopically similar, elastic in the linear range, and exhibits isotropic behavior transversely with no thermal stresses. An example SVBS system is shown to be more efficient with 16% higher normalized (specific) stiffness values when compared to solid slabs of equal thicknesses.