How to give lapping to a column or beam and how much to give these things are very important. Also, in giving extra top to a beam column, the ring barrier and giving ring should be done according to proper rules. Besides, in the case of slabs, crank bars, extra tops, etc. should be taken care of.
From the ideas of various drawings of practical work, some rules for giving columns, beams, and roof rods have been shared, but some things may differ from drawing to drawing. The things that remain roughly the same are highlighted
Rule of barring rings in columns:
- Rings or tie bars are provided on both sides of the column and shall be thicker within a distance of L/4 from the adjacent part of floor and roof and shall be maintained as per the drawing.
- Spacing can be 3/4/5 inches
- Rings or tie bars are provided at the center of the column and are to be provided less frequently outside the distance L/4 from the adjacent part of the floor and roof, maintained as per drawings.
- Spacing can be 6/7/8 inches
Rule of Beam Ring Interruption:
- Rings or tie bars are provided on both sides of the beam and shall be thicker within a distance of L/4 from the adjacent part of the column, to be maintained as per the drawing.
- Spacing can be 3/4/5 inches
- Rings or tie bars are provided in the middle of the beam and are to be provided less frequently outside the distance L/4 from the adjacent part of the column, maintained as per drawing.
- Spacing can be 6/7/8 inches
Extra top in case of beam:
- The amount of extra top at the ends of the beam is given as L/4
- The amount of extra top at the middle support side of the beam is given as L/3
- Extra bottom is provided in beam at distance L/7 or L/8 from column
Rules for giving rods to the roof:
Main Rod and Binder Rod:
- The main rod is provided on the roof in a short direction
- Roof binder rods are provided along the long direction
- The main rod is outside the cage, i.e. up and down
- The binder rod stays inside the cage
Extra Top in Slab:
- Extra top is provided at the edge of the slab up to L/4
- Extra top up to L/3 is provided at middle support of slab
Slab Crank Bar:
- The magnitude of the crank at the end of the slab is L/5
- The magnitude of the crank at the middle support of the slab is given as L/4
- Note: These things are by design, so you have to work S per drawing. But roughly according to the above rules, they can be used in most cases.
