By
Sourav Dutta
Manager-Civil

The first version of BIS 1786 came out in 1985 when in Cl.5.1, the code suggested the nominal sizes as shown below:

Fig 1 (s) : BIS1786-1985 and the relevant clause

The next version of the code BIS 1786 was introduced in 2008, where nominal sizes were rationalized and nominal sizes 7 mm, 18 mm, 22 mm, 45 mm and 50 mm had been removed. In Cl. 6.1, the code had suggested the nominal sizes as shown below:

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By
Sourav Dutta
Manager-Civil

The first version of BIS 1786 came out in 1985 where in Cl.1.1, the code had put the detailed physical and chemical properties, testing procedures of following strength grades of HYSD (High Yield Strength Deformed) bars/wires as shown below:

Fig 1 (s) : BIS1786-1985 and the relevant clause

The next version of the code BIS 1786 was introduced in 2008, where new strength grade Fe600 had been introduced. Also, two categories based on elongation for each grade except Fe600 had also been introduced. Thus in Cl.1.1, the code had put the detailed physical and chemical properties, testing procedures of following strength grades of HYSD (High Yield Strength Deformed) bars/wires as shown below:

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By
Sourav Dutta
Manager-Civil

What is slab?
A RCC (Reinforced Cement Concrete) slab is the most common structural element of any type of building. Horizontal slabs, typically between 4 and 20 inches (100 and 500 millimeters) thick, are most often used to construct floors and ceilings.Here discussion on “flat slab” has not been considered.

Typical loads to be considered for slab design
(i) Dead load: Any permanent load acting on the slab e.g. self-weight of slab, weight of floor finish & plaster

(ii) Live Load: Any non-permanent or moving load e.g. weight of occupants, furniture, and partitionon the slab

(iii) Snow load (if any)

Note: Earthquake and Wind loads are not considered in the design of slabs.

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By
Sourav Dutta
Manager-Civil

Introduction
There are a number of ways in which the superstructure can be built. In areas where average to good quality bricks are available, the walls of houses for two to three storeyed constructions can be built out of bricks with the slabs, lintels, chajja etc. in reinforced concrete. Such construction is termed as load bearing construction (Fig 1). This is essentially because the entire load coming from the slabs, beams, walls etc is transmitted to the foundation through the brick walls.

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By
Sourav Dutta
Manager-Civil
Ion Exchange India Limited

Now-a-days for controlling rust/corrosion of rebar some extra treatment is being carried out on rebar, making it more resistant to rusting/corrosion under unfavorable circumstances. Some of these treated rebars normally used are: (1) Fusion bonded epoxy coated rebar, (2) Cement-polymer composite coated rebar,(3) Corrosion resistant steel (CRS) rebar. The following comparison is being made aiming to give a clear cut idea on advantages/disadvantages of each type, which might help and give an idea to construction industry for decision making of selection of any particular type.

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