Soil Stabilization


In many cases, lime can be used to improve soil workability and load-bearing properties. Quicklime is often used to dry Age soils on construction sites and elsewhere, which reduces waiting time. A more significant use of lime is the stabilization of soil under road and similar construction projects. The use of lime can significantly increase the stability of the substrate, its load-bearing capacity. Both quicklime and Hydrated lime can be used for this purpose.


IMPROVEMENT OF SOIL PROPERTIES WITH LIME: Lime is a perfect material for the short-term replacement of soil properties. Lime can replace almost all well-ground soils, but the most striking development occurs in clay soils with medium to high plasticity. The change occurs because the calcium cations provided by the slaked lime supported by the high pH environment of the lime-water system normally replace the cations on the surface of the clay mineral. Thus, the clay surface mineralogy is modified by creating the following benefits:

• Reduction of plasticity

• Reduction of moisture-holding capacity (drying)

• Reduction of swelling

• Increased stability

• Creation of a dry work platform

SOIL STABILIZATION WITH LIME: Soil stabilization occurs when lime is added to the reactive soil to form long-term strength through pozzolanic reaction. Since calcium comes from lime reacts with soluble aluminates and silicates which comes from the clay, this reaction produces constant calcium silicate hydrates and calcium alumina hydrates. The Pozzolanic reaction can continue for a very long time, even for decades - as long as there is sufficient lime and the pH remains high (above 10). As a result, lime processing can provide high and long-term strength gains. The key of a good pozzolanic reaction is a reactive soil, a good mix and reliable construction applications.

The benefits of soil stabilization are as follows:

• Increases in the modulus of elasticity (in most cases 10-fold or higher)

• Severe improvements in breaking strength (in some cases 20 times or higher)

• Continuous power gain over time, even during periods of environmental or load damage (self-recovery)

• Long-term durability under decades of service and even under severe environmental conditions.

These performance benefits turn into short- and long-term economic benefits.

In addition to the stabilization of new materials, lime is an excellent choice for the recovery of road floors.

Lime stabilization is not a difficult process to perform. After a suitable mixture design and testing have been carried out, onsite mixing is often used to add an appropriate amount of lime at a depth appropriate to the soil. Spraying and mixing is used to combine lime and soil in a comprehensive manner. For heavy clays, the pre-mixing is continued for 24 to 48 hours (or more) of moisture improvement followed by final mixing. Appropriate compression is required to maximize strength and durability. Appropriate improvement is also important. If sulfur is present at levels above 0.3 percent, special procedures are required.