Page 38 - Lecture Notes DCC3113

3.1.3 The uses, types and grades of aggregate and binder

Aggregates

“Aggregate” is a collective term for sand, gravel and crushed stone mineral materials in their natural or
processed state (NSSGA, 1991). In hot mix asphalt (HMA), aggregates are combined with a asphalt
binding medium to form a compound material. The raw material which is used as road aggregate can
be further classified as:
a. Naturally occurring aggregate :
i. Igneus
ii. Sedimentary
iii. Metamorphic

Figure 3-3: Sources natural aggregate

b. Artificial Aggregate
- Blast Furnace Slag
- Burnt Shale

In road construction materials, some other terms used for aggregate are:
i. Coarse Aggregate – pass sieve 28mm and retained sieve 2.36 mm
ii. Fine Aggregate – pass sieve 2.36 mm and retained sieve 75 micron
iii. Mineral Filler – pass sieve 75 micron, consist fine material such as cement, lime, crushed
aggregate dust

Figure 3-4: Different between Fine and Coarse Aggregate

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