Classification of Construction Aggregate Based on Shape

The shape of an aggregate can help efficiently to classify the aggregates in our hands. The shape of the aggregate affects the workability of the concrete mix. Aggregates bought from a standardized dealer will have aggregates with a similar shape. These aggregates can be mixed with another shape to obtain the desired aggregate batch.

The main classification of aggregates based on their shape are:

1. Rounder Aggregates
2. Irregular Aggregates
3. Angular Aggregates
4. Elongated Aggregates
5. Flakey Aggregates
6. Flakey and Elongated Aggregates

1. Rounded Aggregates

These are:

• Smooth Natural Aggregates
• Smoothened by weathering action like erosion and attrition
• Stones, sand, river beds are examples
• These increase workability in a higher manner

2. Irregular Aggregates

These are:

• Irregular Shaped
• Shaped through attrition
• These are not fully rounded
• Gravels are examples
• Reduced workability compared with rounded aggregates

3. Angular Aggregates

These are:

• Take the form of crushed rock and stone
• Used for high-strength concrete
• Workability Impart is low
• Efficiently offset by filling the voids with rounded or smaller aggregates

4. Flaky Aggregates

These are:

• Thin Aggregates 
• Increase the surface area in a concrete mix
• Thickness < (Length and Width)

5. Elongated Aggregates

These are:

• Increases the surface area of the mix
• Demands more cement paste
• Length > (Thickness and Width)

6. Flaky and Elongated Aggregates

• A mix of flaky and Elongated Aggregates
• Imparts least efficient Workability

Read More: Classification of Construction Aggregates