Thumb rule for the percentage of Steel in RCC structures

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    RCC (Reinforced Cement Concrete) is the concrete in which the steel is provided within the concrete to increase the tensile strength of the concrete structure. Concrete has very high compressive strength but it has very low tensile strength. To overcome this steel reinforcement is provided inside the concrete. At the same time both concrete and steel have the same properties like both have nearly the same or similar thermal expansion hence when they expand or contract due to environmental changes both expand or contract at the same rate. Steel can last up to 100 years if it is not exposed to open air with water.

 Thumb Rule

    Thumb rules were used to get quick results for verification purposes in the construction/project site to check or to find how much steel is needed for the work. The thumb rule saves a lot of time in the project since the normal standard methods that are used for the design of the structure are time-consuming. There are various standards in different countries if you want to know who controls or frames the standards check out our article "Code of Practice or Standards for Civil Engineering".

Thumb Rule for Steel Requirement for Footing

    For Footing 0.8% of the Volume of concrete needs to be given as reinforcement. Let's take, for example, the Length, breadth, and depth of Footing 1.52 Meters, 1.52 Meters, and 0.15 Meters. Then the volume of concrete is 1.52 * 1.52 * 0.15 = 0.347 cum of concrete. Therefore 0.8% of concrete is cum (Cubic Meter). Now convert cum to a kilogram of steel multiplied by the unit weight of steel which is 7850 kg/cum. So the steel required will be 0.03 * 7850 = 235.5 kgs of steel required for the construction of the Beam.

Thumb Rule for Steel Requirement for Column

    For Columns 2.5% of the Volume of concrete needs to be given as reinforcement Let's take for example, the Length, breadth, and depth of Column 0.5 Meter, 0.23 Meter, and 3.35 Meter. Then the volume of concrete is 0.5*0.23*3.35 = 0.385 cum of concrete. Therefore 2.5% of concrete is cum (Cubic Meter). Now convert cum to a kilogram of steel multiplied by the unit weight of steel which is 7850 kg/cum. So the steel required will be 0.009 * 7850 = 70.65 kgs of steel required for the construction of the Column.

Thumb Rule for Steel Requirement for Beams

    For Beams 2% of the Volume of concrete need to be given as reinforcement Let's take for example, the Length, breadth, and depth of Beam is 3.35 Meter, 0.23 Meter, and 0.5 Meter. Then the volume of concrete is 3.35 * 0.23 * 0.5 = 0.385 cum of concrete. Therefore 2% of concrete is cum (Cubic Meter). Now convert cum to a kilogram of steel multiplied by the unit weight of steel which is 7850 kg/cum. So the steel required will be 0.009 * 7850 = 70.65 kgs of steel required for the construction of the Beam.

Thumb Rule for Steel Requirement for Slabs

    For slabs 1% of the Volume of concrete need to be given as reinforcement Let's take for example, the Length, breadth, and depth of the slab as 10 Meter, 10 Meter, and 0.15 Meter. Then the volume of concrete is 10*10*0.15 = 15cum of concrete. Therefore 1% of concrete is 0.15cum (Cubic Meter). Now convert cum to a kilogram of steel multiplied by the unit weight of steel which is 7850 kg/cum. So the steel required will be 0.15 * 7850 = 1177.5 kgs of steel required for the construction of the slab.

Member	% of Steel from the Volume of Concrete
Footing	0.8%
Column	2.5%
Beams	2%
Slab	1%