Enviromental Soil Stablilisation Improving and Stabilising Soil Conditions with Lime

The condition of soil can be enhanced through the use of lime and lime kiln dust on construction sites.

Soil Stablilisation

Construction periods can be prolonged by utilising lime to dry soil, hence decreasing the impact of the weather on construction sites. Lime is traditionally used to dry soil as it reacts with water in the soil, releasing heat and therefore ridding wet soil of excess water. Clay-based soil can be altered with the addition of lime and lime kiln dust over a short length of time, producing a material that is able to be broken down into smaller particles, making it more amenable to areas under construction. The soil is more accepting of further treatment, and is less malleable. When enough lime is added, the soil can be permanently stabilised, increasing its strength and decreasing movement – resulting in resistance to repeated freezing and thawing cycles.

Stabilisation as a result of lime addition is different to modifying soil, as the former needs a high pH over a long period of time. This causes chemical reactions in the soil and results in areas of almost cement-like features. This obviously makes for a better base on which to build, due to the nature of the soil being firmer and stronger.

.Lime vs. Limestone

Ground calcium carbonate is known as limestone, and its chemical formula is CaCO3. Calcium oxide, lime or quicklime is written as CaO, and is produced by the calcination of limestone (decomposing CaCO3 into CaO and CO2, or carbon dioxide). In agricultural and other situations, limestone can be referred to as lime, and when limestone is added to soil it's called liming. Technically, though, it's not lime but limestone that is used.

When added to water, chemical lime is highly reactive and produces copious amounts of heat, whereas limestone reacts more slowly. However, both react rapidly with acids. Therein lies the importance of specifying clearly which form of lime is needed for what situation.

Dolomite is frequently utilised instead of limestone. Dolomite is a double salt, with the chemical formula CaMg(CO3)2 – calcium magnesium carbonate.

Lime is used to treat industrial water supplies and waste water, potable water, liquid waste and human or animal solid waste. The lime used should have a high calcium oxide level, be exceptionally pure and have high chemical reactivity.