Examples of Stabilised pavement layers:

Examples

• Sand-clay mixture
• Sand-gravel mixture
• Soil-aggregate mixture
• Soil-soft aggregate mixtures

(b)       Chemical stabilisation by addition of additives like lime, cement, lime and flyash, bituminous materials, etc.

Lime stabilisation is suited for clayey soil, the lime reacting with the minerals and developing cementitious gels. The quantity of lime varies from 2 to 10 percent by weight.

Cement stabilisation is suited for silty and sandy soils. The cement content varies from 3-15 per cent by weight.

Lime-flyash stabilisation is based on the fact that lime reacts with silica in the flyash and produces cementitious gels.

Bituminous materials are used for stabilizing fine sand. Sand-bitumen has been tried successfully on desert roads in India.

Generally, stabilised soils are used for improving the sub-grade and for sub-bases. Soil stabilised layers are also used as a base course for low-volume rural roads.