The Grand Anukampa, a project located in Jaipur comprising of 3 Blocks, out of which Block-C is constructed in voided slab having total area of 61,222 Sq. Ft.
The primary requirement was to have a flat plate slab without any obstruction so that an exposed slab finishing can be achieved.
In order to construct a flat plate for long span and considering slab thickness, RCC slab was not an advisable option. Hence we suggested PT voided slab wherein PT reduces section sizes by controlling deflection and void will further reduce concrete self-weight.
A post-tensioned one-way void slab is proposed in a column free area measuring 121 ft. × 69 ft. with a grid of 3 hidden beams (beams having depth same as that of slab depth and hence aren’t visible from underneath), as a result forming a one-way spanning flat plate of 400mm total virtual thickness. The void slab is made to rest directly on 14 columns at periphery, 4 at corners and remaining 10 on side edges. 550 voids of size 520mm × 520mm × 200mm are used.
Adoption of void slab resulted a flat bottom and achieved considerable reduction of concrete (6 to 7 %). This reduction in concrete volume plus reduced reinforcement caused overall reduction in self-weight of slab resulting in lighter floor. Reduction in self-weight of the slab and provision of hidden beams, eliminated the need of providing columns in the interior area.
Hence, even by using less materials, the structural requirements remains intact and the overall cost is reduced. Also the primary requirement of clear headroom space is achieved.