Are you looking for a clear and practical explanation of what is a spacer bar in the beam? | cutting length calculation | uses? You have come to the right place. In this article, we break down this important civil engineering concept in a way that is easy to understand and apply on the job site.
What is a Spacer bar/Pin bar in the beam?
Spacer Bar is used when there are 2 or more Layers of reinforcements. A steel bar placed in between the two layers of the main reinforcement in the beam is called a spacer bar.
Mostly, it used in Beams to space the reinforcements of the different layer as shown in the image below.
They are in a tapered position or inserted perpendicularly in between the two layers.
Must Read: All You Want Know About Inverted Beam
Why the spacer bars are provided in the beam reinforcement?
As the name implies, spacer bars are provided to maintain a uniform spacing between the two reinforcement layers. Typically, the maximum amount of coarse aggregates size used in beam concrete is 20 mm. The spacer bar maintains a gap between the reinforcement bars for easy flow of concrete aggregate, otherwise, gaps would have formed between the bars.
Due to the spacer bars, the beam is filled with concrete between the bar layers to provide sufficient bonding strength as required.
What should be the spacing & diameter of the spacer bars?
As always, the diameter of the spacer bar should be greater than the maximum size of aggregates used in concrete. Assume that the total size is 20 mm, therefore. The spacer bar diameter should be 25 mm or 32 mm.
Spacer bars should be placed at a distance of 1000 mm C/C. Each other.
How to calculate the cutting length of the spacer bar?
Let us calculate the cut length of the spacer bar for the diagram given below.
Given Data:
Beam width = 400mm.
Beam depth = 500mm.
Clear cover = 25mm.
The cutting length of the spacer bar
= [( beam width – ( 2nos. × clear cover )) +10mm.]
10mm for the grip of the bar
= [ (400mm – ( 2 × 25)) +10mm.]
= [(400mm) – 40mm.] = 360mm
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Also read: Know How To Calculate Quantity Of Steel Requirement For Per m3 | Slab | Lintel | Beam | Column | Foundation |
Conclusion
That wraps up our comprehensive guide on what is a spacer bar in the beam? | cutting length calculation | uses. Mastering these concepts will help you perform better on site and make more informed engineering decisions. Keep visiting CivilNotess for the latest articles, calculators, and construction tips that every civil engineer needs.
❓ Frequently Asked Questions (FAQ)
What is the standard size of TMT bars used in construction?
TMT bars commonly come in sizes of 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, and 32mm diameter. The 8mm and 10mm bars are typically used for stirrups, while larger sizes are used for main reinforcement.
What is the difference between Fe415 and Fe500 grade steel?
Fe415 has a yield strength of 415 N/mm² while Fe500 has 500 N/mm². Fe500 is stronger and allows for using less steel quantity, making it more economical for modern construction.