What is the coefficient method of two way slab?
The Coefficient Method is a quick hand-method of calculating the moments in two- way slabs supported by edge beams. The Coefficient Method was first included in the 1963 edi on of the ACI Code as a method to design two-way slabs supported on all four sides by walls, steel beams, or deep beams.
How moments are calculated in two way slab?
For continuous slabs, the support ends possess negative moments and the middle strip is subjected to a positive moment. Hence, negative and positive moments are determined along the short span (lx) and long span (ly) of the slab. The moments are calculated using the bending moment coefficients given by IS:456-2000.
What is two way beam supported slab?
Two way slab is a slab supported by beams on all the four sides and the loads are carried by the supports along with both directions, it is known as two way slab. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2. In two way slabs, the load will be carried in both the directions.
What is moment coefficient method?
The coefficient method employs tables of moment coefficients for different slab edge conditions. The conditions are based on elastic analysis but inelastic redistribution is accounted for as well. According to the coefficient approach, the slab is divided into the middle strip and column strip in each direction.
When a slab is designed as a two way slab?
When a reinforced concrete slab is supported by beams on all the four sides and the loads are carried by the supports along with both directions, it is known as two way slab. In two way slab, the ratio of longer span (l) to shorter span (b) is less than 2.
What is a two way concrete slab?
Two-way slabs are slabs that are supported on four sides. In two-way slabs, the load will be carried in both directions, thus main reinforcement is provided in both directions for two-way slabs. The slabs are considered as spanning two-way when the longer to shorter span length is less than a ratio of two.
What is 1 way slab and 2 way slab?
In one way slab, the load is carried in one direction perpendicular to the supporting beam. In two way slab, the load is carried in both directions. In two-way slab, the crank is provided in four directions. If L/b the ratio is greater than or equal 2 or then it is considered a one-way slab.
What does moment coefficient mean?
The pitching moment on the wing of an airplane is part of the total moment that must be balanced using the lift on the horizontal stabilizer. If the moment is divided by the dynamic pressure, the area and chord of the airfoil, the result is known as the pitching moment coefficient.
How is the coefficient method used in slab design?
The coefficient method employs tables of moment coefficients for different slab edge conditions. The conditions are based on elastic analysis but inelastic redistribution is accounted for as well. As a result, the design moment on both directions is smaller by a specific amount than the ultimate elastic moment in that exclusive direction.
Which is the ultimate moment at a slab edge?
Various possible support conditions which are considered in the moment coefficient tables are shown in Fig 4. As far as ACI coefficient tables are concerned, Table 1 provides coefficients for negative moments at continuous edges, and the ultimate moment at slab edge is achieved when both adjacent slabs support full dead and live load.
Which is the easiest way to design a two way slab?
The coefficient method may be the simplest, easiest and the quickest approach for the design of two-way slab supported by edge beam on all slab sides. This method was provided in the American Concrete Institute (ACI) in 1963 to design two-way slabs carried by steel beams, deep beam, or walls.
Where is the negative bending moment in a slab?
In this case, negative bending moment will be developed in the top face of the slab at the support both in continuous and discontinuous ends. For restrained slab, IS 456:2000 Table 26 is used for bending moment coefficients. The maximum bending moment per unit width is given by,