Hardore 2

The material used for hardcore should be chemically inert , not appreciably affected by water and be free from water-soluble suphates.

Material used for hardcore are :

• -Brick or tile rubble

1. Clean , hard broken brick or tile crushed and graded
2. Bricks should be free or plaster

• Concrete rubble

1. Clean , broken , well graded concrete is a good material for hardcore
2. THe concrete should be free from plaster

• Gravel and crushed hard rock

1. Clean , well graded gravel or crushed hard rock are both excellent , but expensive materials for hardcore

• Chalk

1. Broken chalk is a good material for hardcore providing it is protected from expansion due to frost

• Road planings

1. When roads are resurfaced , the top of the road is planed off
2. THe planings provide a very good strong hardcore , which binds together when compacted