DCI® Corrosion Inhibitor ASTM C1582 and ASTM C494

Addition Rates

Recommended addition rates range from 2.0 to 6.0 gal/yd³ (10 to 30 L/m3). The level of corrosion protection increases in proportion to the dosage. The project specification will indicate the addition rate. In the absence of a specified dosage, or where needed to offset premixed chlorides, call your GCP admixture technical representative.

DCI also increases the early strength of a concrete mixture and may have an accelerating action on setting time. These effects become more pronounced as the addition rate rises. Control of setting time can be achieved with retarding admixtures (see Set Acceleration).

Mix Water Reduction

Mix water adjustment is essential to account for the water in DCI and thus maintain the desired water/cement ratio. The mix water added at the batch plant must therefore be reduced to compensate for the addition of the corrosion inhibitor. The adjustment factor is 7.0 lbs per gallon of water (.84 kg/L) of DCI.

A high-range water reducer such as ADVA® , DARACEM® 100 or Daracem 19 may be used to maintain workability in low water/ cement ratio concrete.

Compatibility with Other Admixtures and Batch Sequencing

DCI is compatible with most GCP admixtures as long as they are added separately to the concrete mix, usually through the water holding tank discharge line. In general, it is recommended that DCI be added to the concrete mix near the end of the batch sequence for optimum performance. Different sequencing may be used if local testing shows better performance. Please see GCP Technical Bulletin TB-0110, Admixture Dispenser Discharge Line Location and Sequencing for Concrete Batching Operations for further recommendations.

DCI is also classified as an ASTM C494 Type C set accelerator. As such, it may be used to accelerate the set time of concrete. If a neutral set is required, the addition of an ASTM Type B or D set retarder may be added to the concrete mix.

Pretesting of the concrete mix should be performed before use and as conditions and materials change in order to assure compatibility and to optimize dosage rates, addition times in the batch sequencing and concrete performance. For concrete that requires air entrainment, the use of an ASTM C260 air-entraining agent (such as DARAVAIR® or DAREX® product lines) is recommended to provide suitable air void parameters for freeze-thaw resistance. Please consult your GCP Applied Technologies representative for guidance.

Cement Compatibility

DCI Corrosion inhibitor is compatible with all types of Portland cement and concretes containing pozzolans. However, due to the significant variation between cements, even the same type, may result in differences in cement response to DCI. This is especially true with respect to the effect on setting time, which also influences slump retention.

Packaging & Handling

DCI Corrosion inhibitor is Available in bulk quantities from GCP Applied Technologies metered systems or in totes and drums.

Dispensing Equipment

A complete line of accurate dispensers is available. DCI may be introduced on the sand, in the water, at the beginning or the end of the batch cycle. Similar to all concrete admixtures, DCI should not come into contact with other admixtures prior to entering the concrete.

Freezing Point

DCI freezes at approximately 5°F (-15°C), but its corrosion inhibition and strength gain properties are completely restored by thawing and thorough agitation.