1. a.L Rasha jasim Mohamed Lec.10
Highway engineering
12/6/2017
a.L Rasha jasim Mohamed
Lec.10
Al. Rasha j. mohammed

2. Lec.10 Classification of aggregates
A combination of different sizes and shapes normally of stones. Maximum size is 75 mm.
12/6/2017
Al. Rasha j. mohammed

3. • Lightweight aggregate • Normal-weight aggregate
Based on Density:
Based on specific gravity or density measured in bulk, aggregate is divided into 3 types:
• Lightweight aggregate
• Normal-weight aggregate
• Heavyweight aggregate
12/6/2017
Al. Rasha j. mohammed

4. Normal-weight aggregate
Crushed stone, gravel and ordinary sand are examples of normal weight aggregate. They are commonly used in manufacture of normal weight concrete, asphalt concrete and roadway sub-base. Bulk density of normal weight aggregate is around 1520 to 1680kg/m3.
12/6/2017
Al. Rasha j. mohammed

5. Lightweight aggregate Lightweight fine aggregate is any aggregate with bulk density less than 1120kg/m3 and lightweight coarse aggregate is any aggregate with bulk density less than 880kg/m3. They are commonly used as components in the manufacture of lightweight concrete, for making lightweight masonry blocks (to improved their thermal and insulating properties), and lightweight floor and roof slabs. 2 types of lightweight aggregate: • Natural lightweight aggregates (rice husk, etc). • Manufactured (also called synthetic) lightweight aggregates
12/6/2017
Al. Rasha j. mohammed

6. Heavyweight aggregate
Those aggregate with high density and is used primarily in the manufacture of heavyweight concrete, employed for protection against nuclear radiation and as bomb shelter. The unit weight of heavyweight concrete varies from 2400kg/m3.
12/6/2017
Al. Rasha j. mohammed

7. Physical properties of aggregates Strength Texture Durability
Porosity and Permeability
Water absorption
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Al. Rasha j. mohammed

8. 12/6/2017
Al. Rasha j. mohammed