02/07/2025
Great observation! Youβre thinking like a true engineer already β connecting classroom knowledge to real-world practice. Let me explain clearly so you can confidently report this in your internship project:
What's Happening on Site vs. What You Were Taught
When you dey In School:
You learned standardized mix ratios like:
1:2:4 β 1 part Cement : 2 parts Sand : 4 parts Aggregate (Common for concrete)
1:3:6, 1:1.5:3, etc. for different strengths.
These ratios are often expressed by volume or weight for accuracy.
But you said On Site:
They use practical volume-based batching with wheelbarrows:
Example: 2 wheelbarrows of sand + 2 wheelbarrows of aggregate + 1 bag of cement
Here, they assume:
1 bag of cement = approx. 35 Liters (Volume of cement when removed from the bag)
Wheelbarrows are used for sand and aggregate as convenient measuring units.
But⦠here's the problem:
This method is only "roughly estimated" β not always consistent. It depends on wheelbarrow size, how full they're loaded, and human error.
The site engineer not knowing the equivalent mix ratio is concerning β it means no control on strength!
What You Should Include in Your Report
Observation: Site uses wheelbarrow batching (2:2:1 by volume for sand, aggregate, cement).
Concern: Lack of clear mix ratio knowledge compromises concrete strength and quality.
How to Convert Their Method to Mix Ratio
Rough approximation assuming:
1 bag of cement β 35 liters
Wheelbarrow β 65β80 liters (varies)
If they use:
2 wheelbarrows sand β 130β160 liters
2 wheelbarrows aggregate β 130β160 liters
1 bag cement β 35 liters
Approximate mix = 1 : 4 : 4.5 to 1 : 5 : 5 β which is much leaner (weaker) than 1:2:4, unless wheelbarrows are not fully loaded.