One Way Roof Slab Design

One way slabs transfer the imposed loads in one direction only.

One way roof slab design.

When the ratio of the longer to the shorter side l s of the slab is at least equal to 2 0 it is called one way slab shown in figure 8 1 a. Calculate aspect ratio and determine either it is one way or two way slab. Longer span l shorter span b 2. However main reinforcement bar and distribution bar in transverse direction.

Examples of one way slab. One way slab can be defined as the type of slab in which the ratio of the longer span to the shorter span is greater than two. 1 1 a in which the structural action is essentially one way the loads being carried in direction perpendicular to the supporting beams or walls. In other words the one way slab is supported by beams in such a way that the load is carried along one direction.

Simply supported one way slab a rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and 3 75 m apart. They may be supported on two opposite sides only fig. Design a one way slab for the inside of a building using the span loads and other data given in figure 1. The load on the slab is carried by the short span in one direction.

Assuming cover 3 4 in figure 1 the minimum thickness for one way slab simply supported l 20 using table 1 aci 9 5 2 1. Under the action of loads it is deflected in the short direction only in a cylindrical form. One way slab is designed as singly reinforced rectangular section. Normal weight aggregate concrete is specified with a density of 145 pcf.

Calculate the effective span of slab from is 456 clause 22 2 which is least of. L ln h 2 h 2 ln h h depth of slab and l c c distance between supports. Determine the minimum thickness of slab from serviceability criteria of deflection control. The slab has to carry a distributed permanent action of 1 0 kn m2 excluding slab self weight and a variable action of 3 0 kn m2.

One way slab and two way slab. L effective span lesser of the following. When a slab is supported on all four sides and the ratio of long span to short span is equal or greater than two it will be considered as one way slab.