Unstable soil can compromise even the smallest of building projects. Knowing when to stabilize and the basic methods is necessary before beginning any project.
Reasons for Stabilization
Soil stabilization is done before a construction project when the soil has low stability. Soils that need to be stabilized are those with high clay or sand content, as well as wet soils. The more plastic a soil is, the more likely it is to shift, thus requiring stabilization. All building projects should begin with a soil analysis to determine whether stabilization is required. In many areas, building permits won't be issued until this task is completed.
Failure to stabilize the soil properly can cause building foundations to shift over time, which means even with good engineering structural damage can occur. Paved areas, like parking lots and roads, are more likely to develop a wavy surface or even large cracks if the soil isn't properly stabilized prior to construction.
Benefits of Lime Stabilization
A common method of stabilization that is used is lime stabilization. Lime is especially well suited to wet soils that contain a lot of clay, but it is less effective in dry, sandy soils. For those soils, cement is often used instead of lime.
Lime works so well in wet, clay-heavy soils because the fine lime particulates bond with the wet clay and create a firm, interlocking mass of soil that resists water penetration. The result is a firmer, more stable soil base. Most lime stabilization methods use hydrated lime, which also is known as calcium chloride.
Basic Implementation Method
There are three main processes used when stabilizing with lime — pulverizing, additions, and curing. The soil in the site is always completely pulverized and turned before the first addition of lime is made. This ensures that the lime mixes thoroughly into the soil and no clay or wet pockets are left untreated. Once the first pulverization is complete, lime is mixed into the soil and wet down thoroughly. Then the soil is lightly compacted and left to cure, or dry out, for a couple of days.
A second pulverization is completed after the first cure, which further ensures that the lime is integrated well into the soil mix. Once this is complete, a more thorough compaction is done to press out any air spaces in the limed soils. The site is ready to build upon after a couple of days of curing.
Contact a soil stabilization service for more help.