Soil Swelling Test

Expanding soil is a common problem here in North Texas. It’s a phenomenon in which the compounds that make up clay soil soak in water in the air and from recent rainstorms, then expand drastically. Any building above, especially new construction, will be unprepared for the shifting movement of the soil itself. This expansion then leads to cracks forming in the foundation, interior walls beginning to shift, and roadways splintering.

Many of the problems can be alleviated during the construction process by simply testing the soil for expansiveness beforehand. Unfortunately, too few construction companies realize the dangers or delays caused by expansive clay soil.

That’s why, here at Earthlok, we utilize a soil swelling test to determine the nature of expansive soil and how it responds to moisture. If the test proves positive for shifting soils, we can then treat the area using our non-toxic, environmentally friendly soil stabilization solution. We inject this solution directly into the ground around the existing foundation or construction site.

Why Soil Expands

Water in the soil seems to adequately answer the question of why soil expands, but it’s not as simple as that. Moisture is one significant part of the equation, but the problem lies within the makeup of the soil itself.

The expansive clay soil found in North Texas is made up of a number of minerals that expand due to moisture and weather. These include smectite, bentonite, montmorillonite, beidellite, vermiculite, attapulgite, nontronite, and chlorite. Even sulfate salts can lead to expansive clay soil.

The more of these minerals found in the soil, which is where the soil swelling test plays a role, the worse the expansive properties. If we discover extensive amounts of these minerals, your entire construction project could be at risk.

That’s where our soil stabilization solution comes into play. The process is designed to swap out the large water molecules bound to the soil and replace them with smaller ions. These ions force microscopic cracks in the soil closed while also satisfying the electrostatic charge. The clay will then no longer have an affinity to water, meaning the once-expansive soil will no longer warp or swell, protecting your project.

Soil Swelling Testing

There are two primary testing procedures when it comes to expansive soil. These include:

• Plasticity Test – A small sample of the soil is extracted – around 1 cubic inch – and tested for plasticity. The sample is rolled into a thread. If it rolls properly, the plasticity is moderate. If it is difficult, however, the plasticity is low.
• Dilatancy Test – Again, we take a small sample of the soil, shape it into a cube or sphere, and vibrate the sample. If the vibrations cause water to leak to the surface, the clay has low plasticity.

Consider scheduling a soil swelling test before beginning construction of any kind. Call Earthlok at 972-923-9698.