Cement kiln dust (CKD) is a byproduct of Portland cement manufacturing that is highly effective for soil stabilization, subgrade treatment, and road base improvement on Texas projects. Hasten Chemical supplies bulk CKD to contractors and engineers across Texas at competitive pricing.
What Is Cement Kiln Dust?
Cement kiln dust is collected from the exhaust gases of Portland cement kilns. It consists primarily of calcium carbonate, calcium oxide (free lime), silicates, and alkali sulfates. Because of its high free lime content, CKD reacts with clay soils in a manner similar to hydrated lime — reducing plasticity and improving bearing capacity — while also providing some cementitious strength gain over time.
How CKD Stabilizes Soil
When CKD is mixed into clay soil, several reactions occur simultaneously:
- Cation exchange: Calcium ions from CKD replace sodium and hydrogen ions on clay particles, reducing plasticity index (PI) and shrink-swell potential
- Flocculation: Clay particles clump together, improving workability and reducing moisture sensitivity
- Pozzolanic reaction: Long-term cementation develops as CKD reacts with silica and alumina in the clay, increasing unconfined compressive strength
CKD is particularly effective on high-PI black clay soils common throughout Central and East Texas — the same soils responsible for pavement heave, cracked foundations, and road failure.
TxDOT Specifications for CKD
CKD supplied by Hasten Chemical meets the following TxDOT specifications:
- Item 260 — Lime, Fly Ash, or Cement Treatment: CKD used for subgrade soil stabilization on highway projects
- Item 265 — Treated Base: CKD used to stabilize existing base course material
- Item 275 — Cement Treatment (Road Mixed): CKD as a cementitious stabilizer for road-mixed base treatment
- DMS-4600 — Hydraulic Cement: CKD used as a supplementary cementitious material
CKD vs. Lime vs. Fly Ash for Soil Stabilization
Each stabilization material has a role depending on soil type and project requirements:
- CKD vs. Lime: CKD is typically less expensive than hydrated lime and provides similar PI reduction. Lime produces faster initial strength gain; CKD offers slower, longer-term pozzolanic strength development
- CKD vs. Fly Ash: CKD has higher immediate reactivity due to free lime content. Fly ash provides higher long-term compressive strength in treated base applications. The two materials are sometimes blended for optimal performance
- CKD vs. Portland Cement: CKD is significantly less expensive than Portland cement and performs comparably in many stabilization applications, particularly for plasticity reduction
CKD Applications on Texas Projects
Highway Subgrade Stabilization
CKD is specified on TxDOT and county road projects across Texas where expansive clay subgrade requires treatment before base and pavement placement. Application rates typically range from 4–8% by dry weight of soil depending on existing PI and target strength.
Road Base Treatment
CKD can be used to stabilize marginal base material in place, avoiding the cost of base removal and replacement. This is an effective approach for county roads, FM routes, and commercial parking areas.
Commercial and Industrial Site Work
CKD improves bearing capacity on soft or high-plasticity sites where direct slab or pavement construction is not feasible without subgrade improvement.
Bulk CKD Supply and Delivery
Hasten Chemical delivers cement kiln dust in bulk pneumatic tanker loads to project sites throughout Texas. We supply CKD to contractors, civil engineers, county road departments, and private developers across Houston, Dallas/Fort Worth, San Antonio, Austin, and the Permian Basin.
Material data sheets and TxDOT compliance documentation are provided with all orders. Contact Hasten Chemical for CKD pricing and availability on your project.