Hi, in this article i am going to tell you about, what is the clear cover?, why should we provide clear cover?, and how much should be the clear cover for slab, beam, column, and other different RCC concrete structure like retaining wall.
So, lets start the topic with,
What is clear cover?
The clear cover is simply the small distance between the outside surface of concrete and the reinforcement. i.e steel rod provided inside of that concrete structure. This clear cover for different structures depends upon the design of a structure that how much is its length, width, and load on the structure.
But the minimum thickness of clear cover should be taken from Is code which is recommended for different structures like a beam, column, and slab, wall, etc.
Why clear cover is important?
If I say you in one line, then it will be ” clear cover is provided to make the RCC structure long-lasting“.
But let us discuss some of the important of clear cover,
- It is provided to prevent steel rod inside the structure from corrosion due to weather and thermal effect. For example, in the case of fire in the building, the metal begins to melt and lose its strength. So, the clear cover acts as an insulator and prevent from melting. Also in case of weather, it acts as a cover that does not let steel come in contact with the atmosphere and prevent it from corrosion.
- It makes the bond between the steel and concrete which makes it capable to bear compression as well as tensile force.
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How much should be clear cover of the structure?
As initially, i have told you, It depends on types of structure but the minimum clear cover recommended for the different structure is given as,
- The minimum clear cover of the beam should be 25 mm and the column should be 40 mm.
- The minimum clear cover of the slab should be 15 mm. But, for safety rather than economical, we should provide 20 mm.
- The minimum clear cover for footing should be above 50 mm. because all the loads of superstructure are transferred to the ground through the footing. So, it should be more.
- The minimum clear of the column should be 40 mm.
- The minimum clear cover for the raft foundation should be 75 mm.
- The minimum clear cover for the staircase should be 15 mm.
- The minimum clear cover for retaining structure or retaining wall should be 20 mm.
Watch video on clear cover of different stucture
Hence, these are the minimum clear cover for slab and other different structures recommended to provide. Concrete should be prepared with fresh and non-acidic water and by washing aggregate well so that, it does not affect the steel inside in it.
I hope these articles on “Minimum clear cover for slab, column, beam, Retaining Structure” remains helpful for you.
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