RCC Roof Slab – In the construction industry, when they use the word concrete, they are talking about reinforced cement concrete, also known as RCC. The reinforced concrete features combined the strength of cement and steel bars which are the basic components of a modern structural design. RCC is one of the widely used building materials that can be used for creating
- Roofs and slabs
In this post, we will focus on the RCC roof slab reinforcement details which will save you from the hefty consultation fees. If you are planning to utilize the structural element for your home or office building, then you must know how what should be the exact recipe for reinforcement and how to calculate the construction cost.
Benefits of RCC
Concrete features good compression strength but lacks the strength to resist tension. Therefore reinforcement with steel is essential to attain the expected tensile strength. Usually, 6mm to 32mm diameter of steel bars (check type of steel bars here) are used depending on the slab thickness.
To create RCC, you will need cement, coarse aggregate, fine aggregate, M.S. steel bar, binding wire and water along with shuttering materials such as wooden planks and iron plates. Firstly, a cage of reinforcements is prepared in a form work, then concrete is poured and when the concrete is hardened the form work is removed. The reasons people prefer RCC as a structural element for roofs and slabs is that:
- RCC withstands tensile, compressive, bending and shear forces
- RCC is a good fire resistant material
- RCC can be molded to any desired shape
- RCC is remarkably durable and can take any load
RCC Roof Slab Reinforcement Details
If you follow the minimum standards for structural design for modern day buildings you can opt for creating the RCC without a beam, it is called a flat slab. However, including the beams would effectively transfer a load of slabs to the columns, which is good for durability of the structure.
- The cross-sectional dimension for the column can be 9”X9” or 9”X12” with minimum 4 steel bars of 12 MM with stirrups of 8 MM steel rings.
- Ideal beam size should not be less than 9”X9” with a minimum of4 steel bars, with 2 bars of 12 MM thickness in the bottom of the beam, and 2 bars of 10 MM at the top of the beam.
- For slab thickness, it is advised to keep it at least 5” because at some places the slab depth can be less due to electrical pipes and internal wiring. The reinforcement details for RCC roof can be categorized in two ways:
- One way slab: Main steel bars of 8MM and distribution steel bars of 6MM
- Two-way slab: Main steel bars of 8MM and distribution steel bars of 8MM
Every structural design is based on the above-mentioned standards and gaining a general knowledge of these standards will not only help to prevent cheating, but you will also be able to calculate the construction cost for RCC in advance.
How to calculate the construction cost for RCC Roof Slab?
In order to make reinforced concrete, first the form work, then the reinforcement cage is created, and then theright level of concrete mixture is filled and cured for at least month to help it reach its full strength. The entire process can be done with the help of a small contractor, but you need to estimate the construction cost to decide whether the quotation offered by your contractor is acceptable or not.
The construction cost for RCC roof slab depends on lots of variables like:
- Thickness of slab
- One-way or two-way slab
- Construction method and
- Thickness of beam and column
However, you can get a rough estimate with a simple RCC roof slab steel calculation formula. To find out the exact amount it will take to construct an RCC roof slab, let’s take an example.
If the RCC Roof Slab size is 25X20 Sq. Ft. and the concrete mix ratio is 1:2:4 then to find out the construction cost, you will need to calculate
- Concrete slab area
- Concrete cost
- Labor cost
- Shuttering cost
- Steel cost
The steel quantity for the slab will be around 60 to 65 kg per cubic meter. You can take assistance from civil engineers or market experts to find out the steel cost in your area.
Given that the concrete slab area is 25′ x 20′
To convert it into cubic meter
= 7.62 x 6.096 = 46.451 Sq meter
The minimum roof slab thickness is 125mm.
So 46.451 x .125
= 5.806 CUM
The Approx ready mix concrete rate is 3000/cum;
Labor charges for Mason -3no, MC-4no
Shuttering cost is 500
So the concrete cost = (5.806×3000) + 2900+ 500
= Rs 20819/-
To get a rough idea for the construction cost you can get a hint from this formula, however, in general, it is assumed that to construct an RCC roof slab the approx cost would be Rs 180 to 200-00 per Sq Ft, where the cost for steel, labor, shuttering and material is included. But please note, this also vary location to location. E.g construction cost would be different in cities like delhi, mumbai, gurgaon, chennai, jaipur, chandigarh etc.