This article explores the factors affecting the cost of RCC (Reinforced Cement Concrete) and provides an example calculation for a slab.
Factors Affecting RCC Cost:
Concrete Grade: Higher grade concrete (e.g., M20) generally costs more than lower grades (e.g., M15).
Steel Grade and Quantity: Different steel grades and the amount used impact cost.
Mix Ratio: The ratio of cement, sand, and aggregate in the concrete mix affects cost.
Labor Charges: Labor rates can vary depending on location and experience.
Machinery Charges: Costs associated with equipment used for mixing and placing concrete.
Raw Material Costs: Prices of cement, sand, and aggregate can fluctuate depending on location.
RCC Structure Variations:
The amount of steel used in slabs, beams, and columns differs, influencing the overall RCC cost. Slabs typically require less steel than beams and columns.
Rule of Thumb for Steel Quantity:
Columns: 1% to 6% minimum steel requirement.
Beams: 1% to 2% minimum steel requirement.
Slabs: 0.7% to 1% minimum steel requirement.
Example Calculation: 1000 sq ft RCC Slab
Material Assumptions:
Slab area: 1000 sq ft
Thickness: 5 inches (ft / 12 = 0.4167 ft)
Concrete grade: M20
Mix ratio: 1:1.5:3 (cement:sand:aggregate)
Thumb Rule for Material Quantities:
Steel: 80 kg/cubic meter (m³)
Cement: 5 kg/sq ft
Sand: 0.175 cubic feet (cft) / sq ft
Aggregate: 0.350 cft / sq ft
Labor & Shuttering: ₹60/sq ft
Calculations:
Volume of RCC Slab: 1000 sq ft x 0.4167 ft = 416.6 cft
Cubic Meters (m³) from Cubic Feet (cft): 416.6 cft / 35.32 cft/m³ = 11.8 m³
Steel Quantity: 80 kg/m³ x 11.8 m³ = 944 kg (approx. 945 kg)
Cement Quantity: 5 kg/sq ft x 1000 sq ft = 5000 kg (100 bags of 50 kg each)
Sand Quantity: 0.175 cft/sq ft x 1000 sq ft = 175 cft
Aggregate Quantity: 0.350 cft/sq ft x 1000 sq ft = 350 cft
Cost Estimation (Assumed Market Rates):
Steel (₹60/kg): 945 kg x ₹60/kg = ₹56,700
Cement (₹350/bag): 100 bags x ₹350/bag = ₹35,000
Sand (₹40/cft): 175 cft x ₹40/cft = ₹7,000
Aggregate (₹50/cft): 350 cft x ₹50/cft = ₹17,500
Labor & Shuttering (₹60/sq ft): 1000 sq ft x ₹60/sq ft = ₹60,000
Total Cost: ₹176,200
Cost per Unit:
Per sq ft: ₹176,200 / 1000 sq ft = ₹176.20 (approx. ₹176)
Per cft: ₹176,200 / 416.6 cft = ₹423.00 (approx. ₹423)
Per m³: ₹176,200 / 11.8 m³ = ₹14,932.20 (approx. ₹14,932)