Soil Properties
Soil encountered at construction sites is commonly too wet, expansive, or weak to meet structural requirements needed to support roads, buildings, parking lots, airport runways, and other load bearing structures. Soil varies in its moisture content and composition and may contain combinations of clay, silt, sand, gravel, and other inorganic and organic compounds. These properties determine how a soil compacts and absorbs and releases moisture which determines its suitability for construction applications. Calciment stabilizes soil by improving mechanical stability, durability, and volume change characteristics of soil.

Calciment Stabilization Chemistry
When Calciment is mixed into wet soil there is an immediate drying reaction as the calcium oxide hydrates and eliminates water. In fine grained soil such as clay and silt, cation exchange and flocculation reactions occur which improves soil plasticity, workability, compaction, and uncured strength. These immediate effects expedite construction operations when soft, plastic, cohesive soil won't support vehicles or provide subgrade support for paving operations. Following the drying reaction, Calciment begins to cement with the soil. These pozzolanic cementing reactions produce increased unconfined compressive strength, shear strength, tensile strength, reduced permeability and swell potential. Since Calciment is cementitious, coarse grained soil containing sand and gravel can be stabilized where lime alone would fail. Also, the more gradual pozzolanic cementing reactions of Calciment can be beneficial compared to the quick setting rigid nature of Portland cement. Calciment provides greater field working time, typically less cracking and shrinking, and exhibits autogenous healing.

Application Rate, Spreading, Mixing, Watering, Compacting, Curing
Calciment application rates are determined in the geotechnical laboratory where the properties of moisture reduction, compaction, and strength development are optimized. Typical application rates by weight of the soil range from 4 to 10 percent depending on the moisture content and soil type. Calciment is spread as a dry powder by a variety of methods. The newer spreader designs can accurately place Calciment at any application rate while minimizing dusting. Mixing is accomplished with a pulvamixer or rotary stabilizer to a depth of 12 to 18 inches. A disc harrow can be utilized provided several passes are made to assure thorough mixing. When required, water is added during or immediately after mixing with a water truck. The proper water content would allow soil to be molded in your hand without crumbling or be visibly wet. Compaction is accomplished with a sheepsfoot, smooth drum, or rubber tired roller. When bridging poor soil it is important not to make numerous unnecessary passes with the compactor which will push the stabilized soil layer into the unstable soil beneath and cause pumping. Curing or hardening is a gradual process that continues over many days. Geotechnical evaluations are commonly performed at 3, 7, and 28 days to confirm unconfined compressive strength gains. From a practical perspective the construction contractor wants to proceed as quickly as possible and it is not uncommon to support heavy equipment the same day.

	Projects are not delayed by wet weather - Stabilized soil will shed additional rainfall
	Increased unconfined compressive strength of subgrade can allow for reduced pavement thickness in structural designs
	Parking lots and roads will not deteriorate prematurely due to subgrade failure
	Replace expensive cut and fill operations for marginal soils - Pumping soils can be bridged.