STUDIES IN FLAT PLATE AND FLAT SLAB FLOOR SYSTEMS

Abstract

Structural floor transmits the imposed loads including its own self-weight priman. ,ugh flexural action. Simplest amongst the floor systems is the slab simply supported along .1 its sides. This is the case when the slab is supported on a system of brick walls. However, the situation substantially changes when slab is framed into a system of RC columns. Such a floor system is referred-to as Flat Plate. There is shift in bending moment value from mid span to near the supports. The floor starts sharing its moments with the RC column as result of each floor deflection and the moment values decrease. It is, therefore, pertinent to study the suitability of Flat Plate floor system with regard to its range of span and imposed load. A variant of Flat Plate floor system is the one wherein the slab thickness maybe changed to cater to some specific needs in terms of increased shear force. This part of the slab is called as Drop Panel, which results in enhanced shear capacity along with some increase in slab stiffness. As the span increases, the shear along around the column faces also. increases making the slab thickness (including drop panel) inadequate. An attempt is then made to flare up the column cross section just below the slab. This element is called as Column Capital or Column Head. A suitable size of the capital would increase the slab stiffness also and thereby making such a floor suitable for larger span and enhanced load. In the present study, attempts have been made to identify the range of the span, both short as well as long, which would be suitable for Flat plate construction as against the Flat Slab (With or Without Drop Panel). The live load considered is 2kN/m2 for flat plate floor system commensurate with the residential floor loads requirements. The Flat Slab systems have been identified for larger spans and loads commensurate with office / commercial use. The loads adopted are, therefore, 3kN/m2 and 4kN/m2. Appropriate conclusions arrived at have bee presented in the last chapter of the dissertation.