U-BOOT CONSTRUCTION TECHOLOGY

Abstract

U-boot betons is a formwork made of recycled polypropylene, designed to create lightened intermediate slabs and raft foundations in reinforced concrete. The use of U-boot formworks permits to build specific mushroom slabs: the mushroom is part of the slab thickness. U-boot remains dip into the concrete casting. Thus, a grid of orthogonal beams, superiorly and inferiorly closed by plane slabs of different heights, is obtained without executing two distinct concrete castings, all that implies a remarkable saving of concrete and reinforcement. A simply supported reinforced concrete beam has two zones, one above neutral axis and other below neutral axis. The region below neutral axis is in tension and above neutral axis is in compression. As concrete is weak in tension, steel reinforcements are provided in tension zone. The concrete below the neutral axis acts as a stress transfer medium between the compression zone and tension zone. Polythene u boots of varying sizes of 50*50 mm, 60*60 mm & height of 40 cm, thickness of 10 cm at 5 cm, 10 cm, 15 cm spacing u boots are placed in compression zone. Hence the usage of concrete in beams and self-weight of the beams gets reduced considerably. The Load carrying capacity, Deflection of beams and crack patterns were studied and compared with conventional reinforced concrete beams. Key words: Orthogonal Slab, U- Boot, Mushroom slab