Definition of Aggregate:
The material used for manufacture concrete and mortar such as sand, gravel etc. are called as aggregate. The aggregate gives volume, stability, resistant to wear or erosion and other desired physical properties.
The Classification of aggregates are as Follow according to
- Source or nature of formation.
- Size.
- Shape.
Classification of aggregates
According to source or nature of formation:
Classification of aggregate according to source or nature of formation are more classified in four type. These are explain below.
a) Naturally-occurring aggregates-
The aggregates are found in the natural source like sea bed, slope deposits, river Basin e.g. sand and gravel, pit Run.
The recycled aggregate are manufactured by crushing inert construction and demolition waste.
c) Artificial aggregates-
The artificial aggregates are made up by various waste material iron ore, artificial cinders, Burnt clay, Steel rivet etc.
d) Crushed Rock aggregates-
Crushed rock aggregates is formed by crushing the various Rocks quarries e.g. stone aggregate.
Classification of aggregate According to size:
a) Coarse aggregates –
The aggregate having size of particles is more than 4.75 mm are called coarse aggregate. (Range 80mm to 4.75 mm)
b) Fine aggregates –
The aggregate having size of particles is less than 4.75mm are called fine aggregate. (4.75 mm to 150 Micron)
c) All-in-one aggregates –
The aggregate containing both aggregate i.e. fine aggregate and coarse aggregate is called as All-in-One aggregate.
Aggregates according to shape:
a) Rounded –
The shape of aggregate particles is almost circular with even smooth surface. It possess 33-35 % Void ratio. This type of aggregate is not suitable for concreting.
b) Angular –
The shape of aggregate friction is triangular with rough surface. It possess 38-41% void ratio.
c) Flaky-
The shape of aggregate particle is showing less thickness than length and breadth. It has highest percentage of voids. It is suitable for lower grade of concrete.
d) Elongated-
The shape of aggregate having more length than Breadth and thickness.
e) Irregular or partly rounded-
The shape of aggregate is partly rounded with uneven surface. It possess 35 to 37% void ratio. Useful for medium quality concrete.
- Read article on Type of Cement
