Understanding RCC – Reinforcement steel bar or rebar

The strength of your RCC building is decided mainly by

1. Reinforcement steel bars used
2. Their design and use as specified by the structural engineer
3. Placement of columns and beams
4. Concrete mix and grade used in these structures
5. Seismic zone your building is situated.

The steel companies providing rebars are normally Tata, Jindal, and a host of other companies. Please review what each steel has to offer and decide which is best for your building and budget.

What is your contribution to the process?

1. Check which seismic zone your building falls under and choose the appropriate steel quality. For example Tata Tiscon 500D is suitable for certain level of seismic zones.  So choose one suitable for your location and consult structural engineer if any doubts.
2. Diameter of the rebar. Bigger the diameter more the strength and also more weight. So choose appropriate size so that you consider weight/load on the structure along with strength. Do no assume that higher diameter means best for your building. Feel free to question and discuss with structural engineer on any doubts in this aspect. The normal diameter of rebars is 8mm, 10mm, 12mm, 16mm,20mm,25mm in almost all steel providers.
3. Certain aspects of steel such as purity, content, ribbed[for extra binding to concrete], and other steel properties are captured in detail on the website of each of these steel providers. Do give it a read even if somethings are not very clear. It will give an idea on why some brands are costly and the R&D that goes with designing such a rebar.
4. The binding rods which are normally of 8mm or 10mm which are bent into a box shape. The placement of these at every fixed distance is mandatory to provide the required strength. For example these are used to bind the column at every 4 inches or 5 inches as specified in structural drawing. Similarly they are used at fixed distance for the beams.
5. Binding wire is used to bind the intersection points of the vertical and horizontal bars. They hold in place the system and ensure there is no movement during concrete and vibrator usage. This binding also adds to strength of the structure. Every intersection needs to be bound. If missed you can request the barbender [ the person who forms these structure on-site by bending and cutting these rebars.]
6. You can check the drawings and calculate the required number of rods. Earlier the rods were sold on weight and was difficult to verify. Now you can simply place a call on the phone and verify on your site whether the number of rods have arrived. The price is now based on per rod of a given diameter. This is more transparent and reference pricing is provided by the steel company on their website. So you need not be present at booking time since there is no more weighing. You can simply count the number of rebars delivered to your site. If your barbender is providing the request you could simply reverify or clarify on the quantity that he is quoting. There is something about being aware of things going on and having the knowledge to check/re-check/verify/clarify.
7. If you have given for material contract, make sure to pre-discuss on the brand of steel used. This ensures he does not use any cheap rebars since the structure is the most important part of a building. Also you can suggest the better brand or quality and renegotiate the price than to accept something inferior in your building.

Normally in a building construction people discuss on the taps, tiles, etc accessories which are replaceable and forget the most important part of a building, the structure. So please take your time to go through the blog, gain understanding of different aspects, and discuss on the structure – the rebars used, cement used, bricks used, and a good structural engineer for your building before discussing on accessories. Make your house construction a learning and understanding of various aspects. All the best !!

Hope the information presented clears some aspects. Here is a more complete list of articles. Do read about them

• Understanding RCC – structural RCC columns
• Understanding RCC – structural Beam aspects
• Understanding RCC – structural footing drawings