(10) WO 2020/141564 Al
(57) Weight is a highly effective factor in the design of structures with different occupancies, particularly in cases where it increases the gravity and seismic forces acting on the structure. In applications, thickness of the beams and slabs with large spacing must be increased, leading to a corresponding increase in structural weight. Different methods including the hollow-core and the waffle methods have been proposed to reduce ceiling weight in structures. The proposed method in this paper would not only provide a greater ceiling weight reduction than other similar methods, but also eliminate certain limitations associated with the hollow-core method, including the precast production and the one-way action of this design. To this end, permanent forms were designed and placed together inside the concrete to provide end-to-end voids through the midsection of the concrete slab in two mutually perpendicular directions and a greater volume of unworkable concrete would be removed from the slab midsection.
(71) BAHAVAR, Ali [—AR]; Unite 7, No 28, 51 th St, Jahan Ara St, TEHRAN, 1436743353 (IR).