Soil stabilisation is one of the technologies applied when constructing roads and pavements. Its application centers on the excavation and grading processes. Like all technologies, soil stabilisation seeks to make paving construction easier and saves costs through a number of ways.

Increases the weight-bearing capacity of the soil

Under normal circumstances, the soil is too weak to sustain pressure from vehicle use. This is why the grading process is carried out so comprehensively. However, some sites have soils that are too weak to form a suitable sub grade layer, even after compacting. To solve this problem, lime is applied to granulize the soil particles. The chemical reaction improves the structural strength of the soil, creating a strong layer that can withstand heavy use without buckling under pressure.

Speeds up construction

Where the soil stabilisation technology is not applied, the weak sub grade soils have to be removed and replaced with more granular soil types. This is a comprehensive task that consumes quite a lot of time when constructing roads. The process eats into the project timetable, and the contractor may delay construction as a result. However, with application of lime, the weak soils are treated within a matter of hours, and the process continues to take place even after other layers have been added. In other areas, soil stabilisation is also used to dry wet soils such as clay so that excavation and grading can take place. This too saves time as natural drying techniques would take days or more.

Saves cost on paving

Where an unstabilised sub base layer is used, the contractor has to spend more resources excavating the unwanted soil and bringing in truckloads of other stable soil types. Furthermore, the added soil, sometimes not locally available, has to be purchased. The added time before completion of this process also necessitates added labor costs. This bloats the construction budget, costs which are passed down to the customer.

Increases soil drainage

By stabilising the soil, lime creates a layer of impermeable and stable sub grade soil. Ground water beneath this soil layer cannot travel upwards and damage the base course or binder course. Ground water, too, does not penetrate the sub grade course to accumulate beneath the paved road. The ground remains firm, and this prevents cracking of the road as is usually the case when ground water rises and falls.

This chemical stabilisation process remains active for a very long time, maintaining the integrity of the soil and the paved surface above. For more information, see http://www.hiways.com.au.

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