1. What Are Concrete Mix Ratios?

Concrete mix ratios specify the proportion of cement, sand, and gravel in concrete. Standard ratios like M15 (1:2:4) and M20 (1:1.5:3) ensure the right strength and workability for different applications.

2. How Does the Calculator Work?

The calculator uses standard mix ratios and accounts for dry volume:

Explanation: The 1.54 multiplier accounts for the fact that dry materials occupy more volume than when mixed with water.

3. Importance of Proper Mix Ratios

Details: Correct ratios ensure concrete has the desired strength, durability, and workability. Too much cement makes concrete brittle, while too little weakens it.

4. Using the Calculator

Tips: Select the concrete grade (M15 for general construction, M20 for stronger applications) and enter the volume needed. The calculator accounts for dry volume automatically.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between M15 and M20 concrete?
A: M15 has a compressive strength of 15 MPa, while M20 has 20 MPa. M20 uses less sand and gravel relative to cement for higher strength.

Q2: Why multiply by 1.54 for dry volume?
A: Dry materials have air gaps between particles that disappear when mixed with water, so we need more dry materials than the final wet volume.

Q3: How many 50kg cement bags per m³?
A: Approximately 7.5 bags for M15 and 8.1 bags for M20 per cubic meter of concrete.

Q4: Can I use this for large projects?
A: For large projects, consult an engineer as other factors like admixtures may be needed.

Q5: What about water content?
A: Water-cement ratio is typically 0.4-0.6 but depends on workability needs. This calculator focuses on dry materials.