New Form INC

11.17 reading negative reinforcing tables

Tables are prepared for span lengths and span depths for various span configurations. Three distinct slab specifications are catered for :
- Slab specification “B” - refer section 3.6
- Slab specification “A” - refer section 3.7
- Slab specification “R” - refer section 3.8
For each selection of slab and span, three numerical values occur.
            668               General mesh size required.
            12                Negative reinforcement bar size.
            300             Negative reinforcement bar spacing
The negative reinforcing is to be placed as follows
• Slabs to have 25mm cover to top of slab.
• Bar reinforcing is to be placed on top of the mesh. Bars are to be nested into the mesh where possible.
• There is to be no corner lapping of mesh over supports.
• Mesh is to have 25mm cover to topmost part of tray flooring profile.
It is to be noted that as a consequence of the above requirements, congestion plays an important part in continuous slabs and generally it is not possible for 110mm, 120mm and 130mm thick slabs are not able to comply. Therefore, these slab depths are dashed on the span curves, since they are generally restricted to simply supported systems.
Positive FER Tables
For each selection of slab and span, two numerical values occur.
            12                Positive reinforcement bar size.
            600             positive reinforcement bar spacing.
The positive reinforcing is to be placed as follows
• Positive reinforcing is to be placed directly over the intermediate stiffeners placed centrally in the tray floor pans.
• Positive reinforcing is to have 25mm cover to top of intermediate stiffener (total of          45mm cover).
Simply supported slabs are capable of catering for all slab depths included within this manual.