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TECHNICAL TERMS ABOUT REINFORCEMENT A SUPERVISOR MUST KNOW
Reinforcement in concrete may be simple bar or series of bars, bend to a given schedule which is known as bar schedule. It is also one of the most widely used modern building materials.
This article is to enable supervisor going or are already on site to understand how to use this building materials. Below are a few technical terms that should be understand properly.
1: Concrete Cover for Reinforcement
Concrete cover is also called clear cover for reinforcement. and it is the distance b/w steel surface and nearest outer surface of concrete structure.
Concrete cover for different RCC members
- Pile = 75 mm
- Pile cap =75 mm
- Footing = 75 mm
- Column below ground = 65 mm
- Column above ground = 40 mm
- Shear wall below ground = 65 mm
- Shear wall above ground = 40 mm
- Beam below ground = 65 mm
- Beam above ground = 40 mm
- Slab below ground = 50 mm
- Slab above ground = 20 mm
- Stair = 20 mm
: Unite Weight of Steel bar
Site supervisor should be know the unite weight of steel we have given weight of steel for different dia of steel
- 8 mm ø bar – 0.12 kg/ft
- 10 mm ø bar – 0.19 kg/ft
- 12 mm ø bar – 0.27 kg/ft
- 16 mm ø bar – 0.48 kg/ft
- 20 mm ø bar – 0.75 kg/ft
- 25 mm ø bar – 1.25 kg/ft
3: Lap in compression zone:
Steel should be lapping for compression zone with 50d where ( d ) is dia of steel bar
4: Lapping for Tension
Steel should be lapping for tension zone with 40d where ( d ) is dia of steel bar
5: No Lapping
Lap should be not provide larger than 36mm dia of steel
6: Require bending wire
For binding one ton of MS bar 7 kg to 13 kg binding wire is required.
7: Standard length of Mild steel bar
Mild steel Standard length is 40′
8: Minimum Longitudinal Bar in a Column
Use Minimum 4 No’s of steel in Square column and 6 No’s for circular column
9: Placing 1st Stirrup:
Place 1st stirrup with the spacing of 2 inches.
10: Hook’s Angle of Stirrup
Stirrup’s hook angle is 135°.
11: Bend for Vertical Bar of Column
Remember that vertical column bars are called longitudinal bars, and bend is provide at one end of longitudinal bar with the angle of 90 degree and then length should be not less than 18 inches.
12: End Hook for Longitudinal Bar of Beam
Column end hook angel should be with 90 degree
13: Hook’s Length of Stirrup:
The stirrup hook length should be not less than 3 inches or use this formula = 6d where d is dia of steel bar which used for stirrup.
14: Maximum Lap in a Zone
Don’t use more than 50% lapping zone in any RCC structure.
15: Bent Up bar
Provide bent up bar near at support of slab and beam.
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