Page 63 - Lecture Notes DCC3113

4.1.2 Preparation of materials used in the

a. Sub-base
b. Road base
c. Road surface

Preparation of materials used in the sub-base

Materials
Sub-base shall be a natural or artificial mixture of locally available materials such as sand, gravel,
crushed aggregate etc, free from organic matter, clay lumps and other deleterious materials. It shall be
well graded and conform to Table 4.2.2 and the following quality requirements;

Source : Jabatan Kerja Raya, STANDARD SPECIFICATION FOR ROADWORKS, JKR/SPJ/2008-S4,
2008 (page 14)

Preparation of materials used in the Road base

Construction Methods

The FOUR (4) methods for the construction of road base course in flexible pavement
i. Macadam Crusher-Run Road Base
ii. Dry Bound Macadam Road Base
iii. Wet-Mix Road Base
iv. Bituminous Roadbase
v. Cement-Treated Base

Macadam Crusher-Run Road Base

Materials

Crushed aggregate roadbase material shall be crushed rock, crushed gravel or a mixture of crushed rock
and gravel, which shall be hard, durable, clean and essentially free from clay and other deleterious
materials.

The material shall conform to the following physical and mechanical quality requirements;
i. The plasticity index when tested in accordance with BS 1377 shall be not more than 6.
ii. The aggregate crushing value when tested in accordance with MS 30 shall be not more than 25%.
iii. The flakiness index when tested in accordance with MS 30 shall be not more than 25%.

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