Old school thinking in the construction of working platforms, roads, and transportation infrastructure projects misleadingly suggests the only option for improving the engineering properties of clay soil materials is with calcium-based chemical soil stabilization, specifically cement, fly ash and lime. Many clay soils are highly moisture susceptible, making them prone to volume changes and loss of bearing strength with fluctuations in moisture content. While those three calcium-based products inhibit volume change and strengthen soils to varying degrees, they all flocculate the clay. Flocculation destroys the natural cohesion and plasticity and creates an expanded soil structure with lower density. This chemical reaction creates a completely different soil structure that while less prone to swelling and shrinking, comes with a list of negative tradeoffs. Flocculated soil structure contains a greater amount of void space. This altered structure increases the rate that water and air can flow through the soil (permeability), and brings with it the very real risk that the calcium-based stabilizer product will be leached out of the soil along with the benefits it provided. The practice of adding calcium-based chemical stabilizers that flocculate clays soils and increase access to water is a roundabout detour route to solving a stability problem generated by water infiltration and fluctuations in moisture content. Common sense would indicate that solving the water infiltration problem itself would be a better solution, but this line of thinking runs contrary to the mistaken assumption that soil stability can only be achieved by application of the massive quantities of calcium-based chemicals to radically change soil structure and destroy the natural plasticity and cohesion of the clay.

The fact is that clay soils can be stabilized in a far more cost-effective and sustainable manner using chemistry that retains plasticity while strengthening cohesive forces and better organizing soil structure to resist water infiltration, essentially working with the strengths of the clay rather than changing it into an entirely different type of material. Clay soils offer natural benefits for use as building materials. They have cohesive strength and elastic behavior (plasticity), and they are relatively impermeable in comparison to other types of soil. Adobe bricks are among the oldest building materials and include clay soils in their composition. The liners for the bottom of landfill cells, and the caps for the permanent closure of the cells require the use of clay soils in their construction. Clay soils can provide durable low-permeability barriers with elastic and self-healing properties to resist the development of cracks that otherwise would be generated by ground movement and subsidence of the closure cap as landfilled waste decomposes over time. When clay soils are maintained at or near their optimum moisture content, which is the moisture content at which a particular soil can be compacted to its highest density, they provide impressive strength and hardness as well as resistance to cracking and erosion.

EMC SQUARED System stabilizer products are the alternative to cement, fly ash and lime stabilizers. As opposed to these three extreme pH, calcium-based chemicals that are applied in bulk quantities at great cost and effort, the neutral pH EMC SQUARED System products are highly concentrated liquids applied to the soil as additives to the compaction water during standard earthwork construction procedures. Without radically changing the pH, plasticity or natural structure of the treated soil material, EMC SQUARED stabilizers increase strength and density and help stabilize the moisture content of the stabilized soil within range of its optimum moisture content. The treated soil sheds rainwater and resists the rise of capillary water, thereby functioning as a moisture barrier as well as a stable and erosion-resistant working platform. Stabilizing the moisture content of the soil in a state of equilibrium eliminates the fluctuations in moisture content that otherwise drive the volume change of expansive clay soils, commonly known shrinking and swelling, that is so highly destructive of road pavements and other built structures. Without fluctuations in soil moisture content, there is no shrinking and swelling.

Next time the use of a calcium-based soil stabilizer is under consideration, or the purchase and import of a large quantity of crushed aggregate base course material, take time to review over thirty years of EMC SQUARED project case histories and test results and then schedule laboratory or field testing of what could be a far more cost-effective and sustainable solution.