18 Technical Terms about RCC you should know
Role of a Site Supervisor in Construction Project
A Site Supervisor supervises the health & safety of a construction site. The Site Supervisor manages and assesses any potential safety hazards on site and looks at eliminating them. He reads specification sheets for information, such as sizes of aggregates and proportions of cement and water required, to ensure that concrete is mixed according to specifications and should be well aware with the concrete technical terminology.
The Construction Site Supervisor should have a positive attitude and be able to motivate their team. They must have an overall understanding of health & safety, be able to read site drawings and documents and have strong organisational skills.
Concrete Cover Specifications for Reinforcement in Different Codes
Concrete cover is assumed to be the first measure considered to prevent influences of aggressive elements on the reinforcement steel bars. That is why utmost cautions are needed during concrete cover thickness design and its construction.
The specification of different codes regarding concrete cover is commonly dependent on nature of the structure, method of construction, environmental factors around the structure, and quality of concrete utilized in the construction.
Concrete cover alias clear cover refers to the distance among the surface of reinforcement nearest to the adjacent exterior surface of concrete member.
1. The safeguarding of the steel from erosion.
2. The movement of bond forces securely.
3. Sufficient fire resistance.
Concrete cover varies based on the size and position of RCC member
Get the values of concrete cover for different RCC members as follows:
Pile – 3″ or 75 mm
Pile cap – 3″ or 75 mm
Footing – 3″ or 75 mm
Column underneath ground – 2.5” or 65 mm
Column over ground – 1.5” or 40 mm
Shear wall underneath ground – 2.5” or 65 mm
Shear wall over ground – 1.5” or 40 mm
Beam underneath ground – 2.5” or 65 mm
Beam over ground – 1.5” or 40 mm
Slab underneath ground – 2″ or 50 mm
Slab over ground – 0.75” or 20 mm
Stair – 0.75” or 20 mm
Retaining wall’s earth face – 1.5” or 40 mm and opposite face: 1″ or 25 mm
Door-window lintel –0.75” or 20 mm
Sunshade – 0.75” (20 mm)
2) Stirrup’s hook length: The formula 6db is used to work out the hook length of stirrup. Here “db” denotes the diameter of bar. The hook length should not be lower than 3".
3) End Hook for Longitudinal Bar of Beam: End hook is placed in both end of longitudinal bar. The length of hook should not be under 12db.
4) End Hook of Slab Top Reinforcement: End hook length of slab’s top bar shouldn’t be lower than 12db.
5) Bend for Vertical Bar of Column: Vertical bar of column is also known as longitudinal bar. Bend is given at one end of longitudinal bar. The bend should be 90° and length of bend should not remain under 18″(450 mm).
6) Anchorage Length of Cantilever Member: The anchorage length of main bar of a cantilever RCC member should not remain under 69db.
7) Hook’s Angle of Stirrup: The hook angle of stirrup should be 135°.
8) End Hook’s Angle of Longitudinal Bar: End hook angle of longitudinal bars of column and beam should be 90°.
9) No Lap Bar: If the diameter of MS bar is greater than 36 mm, it should not be lapped.
10) Maximum Lap in a Zone: In one zone, greater than 50% of bars shouldn’t be lapped.
11) Lap in Tension: There should be no lapping in tension zone.
12) Placing 1st Stirrup: 1st stirrup of beam should be set within 2″ from the support.
13) Least Longitudinal Bar in a Column: A square-shape column should contain least 4 numbers of bars and a round column should contain least 6 numbers of bar.
14) Chair: MS bar for chair shouldn’t be lower than 12 mm diameter.
15) Unit Weight of MS Bar:
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.
16) Standard Length of MS Bar: Total length of a deformed MS bar should be around 4o feet.
17) Required Binding Wire: To tie one ton of MS bar, 7 kg to 13 kg binding wire is necessary.
18) Minimum Longitudinal Bar in a Column: A square-shape column should have minimum 4 numbers of bars and a round column should have minimum 6 numbers of bar.