How is ribbed slab constructed?

Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. Normally the ribs and the beams are the same depth. A thin topping slab completes the system. Waffle slabs tend to be deeper than the equivalent ribbed slab.

What are the techniques in the construction of waffle floor?

Traditional construction technique of waffle slab system includes the storage of materials, establishment of supports and formwork assembly in situ for worker convenience. Consequently, reinforcement is cut and tied followed by the insertion of opening steel cylinder into the reinforcement.

What is a rib in construction?

And all done with low wages laborers. At left a sketch of the steel reinforcement of the stem (rib) where rebars and stirrups are designed by structural calculations, to take the loads and stress depending of the conditions of the location of the building.

Where is ribbed slab used?

Ribbed slabs are suitable for medium to heavy loads, can span reasonable distances, are very stiff and particularly suitable where the soffit is exposed. Slab depths typically vary from 75 to 125 mm and rib widths from 125 to 200 mm. Rib spacing of 600 to 1500 mm can be used.

What is the disadvantage of ribbed slab?

Disadvantages of Ribbed and Waffle Slabs Not suitable where the live loads are huge as heavy manufacturing buildings, warehouses. The thickness of the slab is controlled as the requirement of fire resistance. Formwork cost is high. Sometimes difficult to install the electric equipment.

What is two way ribbed slab?

Two-way joist slab often called two-way ribbed slab or waffle slab is an economical floor system when the spans are long and/or loads are high.

What is the maximum span for flat slab?

Examples of slab thickness and indication of maximum span for solid slabs with ordinary ( ) and prestressed ( ) reinforcement according to [2]. The allowed recommended span lengths for continuous slabs are equal to 13.6m for two-way slabs and to 12.5m for unidirectional slabs.

What is the difference between raft slab and waffle slab?

Q: What is the difference between a raft slab and waffle slab? A: The primary difference between the two is raft slabs cast against the ground. Waffle slabs, on the other hand, cast upon polystyrene void formers and strips of concrete.

What is another name for vertical ribs in construction?

rib vault, also called ribbed vault, in building construction, a skeleton of arches or ribs on which masonry can be laid to form a ceiling or roof.

What is meant by ribbed slab?

Ribbed or waffle slab is a slab system which consists of series of parallel reinforced concrete T beams framing into reinforced concrete girders. The slab is the flange of the beam and the extended part is the web. The extended part is known as ribs. The spacing between the ribs should be in general 20-30 inch.

What is the advantage of ribbed slab?

Ribbed Slabs: The main advantage of ribbed floors is the reduction in weight achieved by removing part of concrete below the neutral axis. This makes this type of floor economical for buildings with a long span with light or moderate loads. This includes apartment buildings and hospitals.

What is two-way ribbed slab?

How is a one way ribbed slab analyzed?

One way ribbed slab as a model is analyzed by the two methods “traditional and the finite element method “. The Slab was 6*10m simply supported on four sides and subjected to uniform load 1t/m 2and as shown in Fig. (1). Fig. (1) geometry for one way ribbed slab The load on each rib equals 0.5 t/m` The shear force and the bending moment are

How to install a concrete slab with ribs?

If using Polystyrene block system, first place 6 concrete trays, thereafter place polystyrene block, then place cross ribs. Place reinforcement in transverse cross-ribs and place mesh reinforcement sheets over slab area.Place electrical conduit pipes and/or plumbing services. Clear all rubble on ribs and blocks and wet slab thoroughly. 1.

How is the concrete rib construction method managed?

CONCRETE RIB CONSTRUCTION METHOD, (CRCM) uses the engineering technology to design the elements structural’s to handle the loads originated by climatic and or geographical location of the project. The cost is managed by supervision of non skilled laborers, following the recommendations in this Manual.

What kind of reinforcement do you use on a ribbed slab?

The rib reinforcement follows the same rules with the beam reinforcement. However, mainly as far as the stirrups are concerned, the amount of placed rebars is not as large as it is in beams. Between the ribs, the slab is usually reinforced with a common wire mesh.