Yes, I know. The right proportioning of ingredients to be mixed for preparation of concrete is called batching of materials for concrete production.

Types: Volume Batching and Weight Batching.

Weight Batching is preferred due to following reasons.

1. Correct method
2. Provide accurate ratio of constituents as per design on the basis of specific gravity of materials.
3. Moisture content presence in the aggregate should also be considered while batching. In case of fully automatic weight batching it can be considered but volume batching is not suitable in such cases.
4. Compressive strength of same concrete mix at 7 days and 28 days is higher for weigh batching concrete mix than volume batching concrete mix.

Shape of Aggregate – Rounded, Angular, Flaky, Elongated

• Rounded – minimum voids, require minimum cement but poor interlocking and bonding.
• Angular – Higher voids, require more cement, but best interlocking and bonding.
• Flaky: Aggregates having its least dimension less than 0.6 times its mean dimension. It has poor bonding and has adverse effect on homogeneity of mix and its strength.
• Elongated: Aggregates having its larger dimension greater than 1.8 times its mean dimension. It has poor bonding and not considered suitable for medium to high strength concrete

Size of Aggregate – Fine, Medium and Coarse

• Fine
• Medium
• Coarse

The maximum size aggregate gives the lower surface area for the development of gel bonds which is responsible for the low strength concrete. Also, non-uniformity in concrete.

Large Aggregate – Lean Mix – High Strength

Smaller Aggregate – Rich Mix –High Strength