Factors That Impact Lime Stabilization Of Soils

When building roads or putting in foundations, stable soil is a must or it can settle and shift until the new construction suffers damages. Lime stabilization is one effective method for stabilizing the site.

Soil Structure

The structure and soil type is the main consideration when determining whether lime stabilization is the right option. Lime works best in clay soil with a fine grain structure. These soil types typically have plenty of silica within, which will react with the calcium in the lime to form a strong bond reminiscent of cement. Lime doesn't work as well in coarse-grained soils with little clay content, so in these types of soil other soil stabilization methods may be recommended.

Availability

The availability of lime in your area may also impact your stabilization technique. Lime stabilization is done with a specific type of lime, typically referred to as quicklime. This lime either consists of calcium hydroxide or calcium oxide. Other types of lime, like agricultural lime, will not work for stabilization purposes. If quick limes are readily available in your area or mined nearby, then it is a cost-effective stabilization solution. If the lime must be shipped in, then the cost can be prohibitive and it may be better to research other options like cement stabilization.

Site Depth

One issue with lime stabilization methods is that one can't just spread the lime over the site surface and expect it to stabilize sufficiently. Lime must be worked into the top layer of the soil, sometimes to a depth of a foot or more. Otherwise, the top of the soil will form a crust and stabilize, but soil movement will continue beneath this top crust. Working in the lime requires heavy equipment and time, which can add to the cost of a project. The soil must also be relatively free of large obstructions like rocks so that the equipment can incorporate the lime as needed. Of course, ensuring the soil is properly stabilized will prevent issues later down the road, such as cracks in a roadbed or foundation. 

Moisture Level

The chemical reaction between the lime and the soil that leads to stabilization only occurs if moisture is present. This is one of the reasons why clay soil works so well with lime -- it naturally tends to hold moisture. Moisture can be provided by the installers at the time the lime is spread to begin the process, but some natural moisture in the soil will be needed to ensure that full stabilization occurs.

Contact a construction company to learn more about lime stabilization. 

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