Concrete, an essential building material, comprises cement, sand, aggregates, and water. Its versatility allows for the creation of robust structural elements. In this guide, we’ll walk through the steps to determine the amounts of cement, sand, aggregate, and water needed for 1 cubic meter of concrete.
Important Estimation Points
Density Values:
- Density of Cement: 1440 kg/m³
- Density of Sand: 1450 – 1500 kg/m³
- Density of Aggregate: 1450 – 1550 kg/m³
Cement Bag Information:
- Weight of Cement Bag: 50 kg
- Volume of 1 Bag Cement (in cubic meter): 0.03472 m³
- Volume of 1 Bag Cement (in cubic feet): 1.226 ft³
- Number of Cement Bags in 1 cubic meter: 28.8 bags
Conversion Factors:
- 1 Cubic Meter (1 Cum) = 35.31 Cubic Feet (35.31 cft)
For M-15 Grade Concrete
Grade and Mix Ratio:
- Grade of Concrete: M-15
- Mix Ratio: 1:2:4 (cement:sand:aggregate)
- Sum of Ratios: 1 + 2 + 4 = 7
Volume Calculations:
- Wet Volume of Concrete: 1 cubic meter
- Dry Volume of Concrete (after 54% increase): 1.54 cubic meters
Understanding the 54% Increase:
Dry materials like aggregate, sand, and cement have air voids. These voids are approximately 33-34% for aggregate, 20% for sand, and negligible for cement due to its fine particles. When combined, the air voids in sand and aggregate total 20% + 34% = 54%, which is why we increase the volume by 54% to get from wet to dry volume.
Quantity of Cement
Step-by-Step Calculation:
-Dry Volume / Sum of Ratio × Ratio of Cement
- 1.54 / 7 × 1 = 0.22 cubic meters (where 1 is the cement ratio)
-Quantity of Cement in kg
- 1.54 / 7 × 1440 (Density of Cement = 1440 kg/m³)
-Quantity of Cement in Bags
- 316.8 / 50 = 6.336 bags (weight of one bag of cement = 50 kg)
-Quantity of Cement in Cubic Feet
- Number of Bags × 1.226 (Volume of 1 bag of cement = 1.226 ft³)
Quantity of Sand
Step-by-Step Calculation:
-Dry Volume / Sum of Ratio × Ratio of Sand
- 1.54 / 7 × 2 = 0.44 cubic meters (where 2 is the sand ratio)
-Quantity of Sand in kg
- 0.44 × 1450 (Density of Sand = 1450 to 1500 kg/m³)
-Quantity of Sand in Cubic Feet
- 1.54 / 7 × 2 × 35.314 (1 Cum = 35.314 cft)
- Result: 15.53 cubic feet
Alternative Calculation for Sand in Cubic Feet
- Number of Cement Bags × Volume of one Bag of Cement in Cubic Feet × Ratio of Sand
- Result: 15.53 cubic feet
Quantity of Aggregate
Step-by-Step Calculation
-Dry Volume / Sum of Ratio × Ratio of Aggregate
- 1.54 / 7 × 4 = 0.88 cubic meters (where 4 is the aggregate ratio)
-Quantity of Aggregate in kg
- 0.88 × 1500 (Density of Aggregate = 1450 to 1550 kg/m³)
- Result: 1320 kg
-Quantity of Aggregate in Cubic Feet
- 1.54 / 7 × 4 × 35.314
- Result: 31.07 cubic feet
Alternative Calculation for Aggregate in Cubic Feet
- Number of Cement Bags × Volume of one Bag of Cement in Cubic Feet × Ratio of Aggregate
- Result: 31.07 cubic feet
Quantity of Water
Considering Water Cement Ratio = 0.45:
- Water requirement for 1 bag of cement = 0.45 × 0.03472 (Volume of 1 bag of cement = 0.03472 cubic meters)
- Result: 0.0156 cubic meters
1 cubic meter = 1000 liters, so:
- Water requirement for 1 bag of cement = 0.0156 × 1000
- Result: 15.6 liters
Finally, for 6.336 bags of cement:
- Water requirement = 6.336 × 15.6
- Result: 98.93 liters
Conclusion
For M-15 grade concrete (1:2:4), the quantities needed are:
- Cement: 6.336 bags
- Sand: 0.44 cubic meters
- Aggregate: 0.88 cubic meters
- Water: 98.93 liters
Similarly, you can calculate the quantity of materials for different mix ratios.
