<p>Here Plan of slab for access crossing including ms grating , pre cast concrete slab <strong>the top and bottom extra bars that usually provided along slab openings should be at least equal to the area of the openings which supposed to have a steel reinforcement or a mesh reinforcement</strong>. The total area of these rebars should be distributed along the side of the slab openings. A slab is <strong>a structural element, made of concrete, that is used to create flat horizontal surfaces such as floors, roof decks, and ceilings</strong>. A slab is generally several inches thick and supported by beams, columns, walls, or the ground.a height of not less than 2.4 m measured from the top of the floor to the lowest point of the air-conditioning duct or the false ceiling should be provided for more details download this file.</p>