FAQs

Roadbond EN 1 has been in commercial use since 1986. It has a documented track record across hundreds of projects spanning multiple climates, soil types, and construction methods.

Lime works primarily by raising soil pH and driving pozzolanic reactions over time. Roadbond EN 1 works via ion exchange — replacing weakly ionized water in the clay matrix with strongly ionized sulfate radicals. As with lime, metal hydrates form to increase strength, but the clay matrix is left intact, which reduces permeability significantly. Independent testing has measured Roadbond-treated soil as approximately two times less permeable than untreated soil and four times less permeable than lime-treated soil.

Roadbond EN 1 enhances conventional stabilizers rather than competing with them. When added to a Portland cement or fly ash mix design, it allows the conventional stabilizer to be reduced by 40% to 50% without a corresponding loss of strength. In documented field work, fly ash blends moved from Class II base to Class I base simply by adding Roadbond EN 1. It also significantly reduces the reflective and block cracking commonly associated with cement stabilization.

Yes. The ion exchange that occurs at the clay surface is permanent. Field trials and lab tests confirm that strength continues to improve over time rather than degrading.

Roadbond EN 1 is most effective on clayey soils, including high plasticity index (PI) clays, and on base or recycled in-place material containing fines. It has been tested on sulfate-bearing clays, where conventional lime stabilization is prone to sulfate-induced heave. Project-specific lab work is recommended to confirm dosage and design strength.

Roadbond EN 1 is diluted with water in a water truck, then sprayed onto the soil to be treated. The soil and stabilizer solution are mixed with a reclaimer or rotary mixer, compacted to density, and finished — all in one operation. Many projects are placed and paved in less than five days.

The manufacturer specifies dosage based on the volume of soil to be treated. As a general benchmark documented in third-party research, the rate works out to approximately 30 cubic yards of soil per gallon of undiluted product. Project-specific lab design is used to confirm the dosage for the soil and depth in question.

Per standard specification, soil moisture content at the time of installation should not exceed optimum moisture content by more than 3% (ASTM D698, measured by ASTM D2216 or D3017). If moisture is above the limit, the soil is aerated and re-mixed before stabilizer is applied.

Density is controlled per ASTM D698 or as directed by the engineer. A common acceptance criterion: of the most recent five consecutive density tests, no more than one may fall below the specified density, and the failing test must not be more than 80.74 lbs/CY below the spec.

One 5-gallon jerrycan of Roadbond EN 1 replaces approximately 12 tons of lime — roughly 1⅓ truckloads of bulk material. On a representative 54,000-square-yard project, 300 gallons of Roadbond EN 1 replaces 80 or more truckloads of lime delivered to the job site.

Yes. Standard installation specifications are published by the manufacturer and have been adopted into project documents under “Roadbond EN 1 or approved equal” language. Specifications cover materials, water, equipment, mixing, compaction, density, and thickness tolerances. They are available from CSS Technology on request.