Ratio of Steel required to Cement Concrete
In civil engineering the thumb rule for Steel to Concrete ratio is 100:130. The ratio means for every 130 kg concrete 100 kg of steel is needed. 100 kg of steel strengthen the structure in RCC. Failing this ratio of steel to concrete would cause weakening the structure and fatal cracks to it. Based on the construction type ratio of TMT Steel Bar to Concrete is:
Civil Construction / Heavy Industrial Construction = 130 kg/m3
Commercial Construction = 100 kg/m3
Institutional Construction = 90 kg/m3
Residential Construction = 85 kg/m3
In case of civil constructions the structure remain unchanged however for building constructions the ratio may vary. It depends upon the nature of building. For example a multi-storied building meant to be strong rather than a 3 storied building.
The Steel Bars that are used for construction should be best in quality. Important factors that determine the strength of concrete are:
- Age of Concrete
- Temperature in the applied place
- Humidity in that area
- Curing
- Quality of other raw materials
Higher Salt, Sulphate, Chlorides reduces the strength in concrete. Aggregates should be fine and as per requirement in RCC. Mixture should be even and there should not be any lumps to it.
For different parts of the house different quantities of Reinforcement Bar is needed. An estimation chart here below that will explain that how much TMT Bar is required in kg for different parts of a building.
| Different Parts of the Building | Requirement of Steel TMT Bars in Kg |
| Ground Beams | 230-330 |
| Columns | 200-450 |
| Beams | 150-300 |
| Load Bearing Slabs | 150 |
| Capping beams | 135 |
| Stairs | 130-170 |
| Joint beams | 130-170 |
| Rafts | 115 |
| Light Loaded Columns | 110-200 |
| Walls (Retainers) | 110-150 |
| Pile Caps | 110-150 |
| Light Loaded Beams | 100-150 |
| Plate Slabs | 95-135 |
| Bases | 90-130 |
| Floor Slabs | 80-120 |
| One way Slabs | 75-125 |
| Two way Slabs | 67-135 |
What is RCC? Why TMT Bar is required in RCC?
RCC stands for Reinforced Cement Concrete.
Cement Concrete carries strong compressive strength but it has no tensile strength. Therefore TMT Bars are used in Cement Concrete to increase the tensile strength. Without using TMT Bars no structure can withstand during an earthquake. TMT Steel Bars/Reinforced Bars are highly ductile and for its tensile strength it can hold the building during an earthquake.
For different concrete grades different quantity of the materials are required.
| Concrete Grade | Proportion of Cement : Sand : Stone pieces | Expected Compressive Strength at 28 days |
| M10 | 1 : 3 : 6 | 10 N/mm2 or 100 Kg/cm2 |
| M15 | 1 : 2 : 4 | 15 N/mm2 or 150 Kg/cm2 |
| M20 | 1 : 1.5 : 3 | 20 N/mm2 or 200 Kg/cm2 |
| M25 | 1 : 1 : 2 | 25 N/mm2 or 250 Kg/cm2 |
TMT Bar adds strength to the RCC. Various elements of RCC constructions are slabs, beams, foundation etc.
It is always recommended to maintain the accurate ratio as per the type of construction. TMT Bar is the main component in RCC that gives the tensile strength to your home. All architects, engineers recommend using the best quality TMT Bar in RCC.