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Standard Concrete Mix Ratios:
M15 Grade: 1:2:4 (Cement: Sand: Aggregate)
M20 Grade: 1:1.5:3 (Cement: Sand: Aggregate)
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Concrete mix ratios represent the proportion of cement, sand, and aggregate used in concrete preparation. These ratios determine the strength and workability of the concrete.
Common standard concrete mix ratios:
M15 Grade: 1 part cement : 2 parts sand : 4 parts aggregate (Normal strength concrete)
M20 Grade: 1 part cement : 1.5 parts sand : 3 parts aggregate (Standard strength concrete)
Explanation: The numbers represent the volume ratio of each component. For example, M15 means for every 1 unit of cement, you need 2 units of sand and 4 units of aggregate.
Details: Correct ratios ensure the concrete has the desired strength, durability, and workability. Improper ratios can lead to weak concrete or excessive cracking.
Tips: Select the desired concrete grade and enter the volume needed in cubic meters. The calculator accounts for the dry volume (54% more than wet volume).
Q1: What does M15/M20 mean?
A: The number represents the compressive strength in MPa (15 MPa or 20 MPa) that the concrete should achieve after 28 days of curing.
Q2: How much water should I add?
A: Typically 0.4-0.6 times the weight of cement, but this depends on required workability and aggregate moisture content.
Q3: Can I use different ratios?
A: Special projects may require different ratios, but standard ratios work for most general construction purposes.
Q4: How accurate are these calculations?
A: They provide good estimates for small projects. Large projects should use precise batching plants.
Q5: What if my sand is wet?
A: Wet sand occupies more volume. Either measure sand by weight (about 1600 kg/m³ dry) or account for bulking (typically 20-30% more volume when wet).