Efflorescence Control Admixture

Product Description

OPTEC® EC-925 is an innovative admixture specifically formulated to enhance the overall appearance of hardscapes and architectural concrete masonry units. OPTEC EC-925, is a unique blend of novel ingredients that help improve and retain color vibrancy by controlling both primary and secondary efflorescence. OPTEC EC-925 also contains a “slip” ingredient that aids in workability and provides a smooth modest swipe texture on the surface of the unit.

Product Uses

OPTEC EC-925 may be used in hardscapes such as concrete pavers, concrete slabs and segmental retaining wall units. Other uses where improved aesthetics are desired include architectural block, concrete brick, manufactured stone veneer and cast stone units. OPTEC EC-925 is designed to reduce both primary and secondary efflorescence, while maintaining unit physical properties.

Product Advantages

  • Controls primary and secondary efflorescence
  • Optimized for dosage efficiency
  • Improves cement and pigment dispersion

Product Function

OPTEC EC-925 improves the dispersion of the cement throughout the mix. Through this dispersion action, cement and consequently pigment reductions are possible. OPTEC EC-925 improves the plasticity of the mix for improved machinability and reduced cycle times.

Application Information

OPTEC EC-925 is typically used at a rate of 2-4 oz./cwt (130-260 mL/100 kg) of cementitious materials including pozzolans. The addition rate is dependent upon the specific set of materials and the desired end properties.

Mixing Procedure

OPTEC EC-925 is compatible with most admixtures. However, when multiple admixtures are used they must be added separately to the concrete.

OPTEC EC-925 is typically added separately to the mix after all of the ingredients have been added. Shorter mix cycles may warrant adding either on prewetted aggregates or after the cement has been “wetted out”. OPTEC EC-925 should be mixed for a minimum of one minute, but preferably two minutes. Never add OPTEC EC-925 to dry cement. Variables such as cementitious content, aggregate gradations, processing equipment, and curing conditions may have an impact on the effectiveness of OPTEC EC-925. Testing with local materials and production equipment is necessary to determine the end results.

Packaging and Handling

OPTEC EC-925 is available in drums and returnable totes.

Dispensing Equipment

OPTEC EC-925 can be dispensed using conventional air diaphragm pump systems. For further information, contact your local GCP representative.

Health and Safety

All precautions defined on the SDS (Safety Data Sheet) must be followed.


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We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with ourconditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

OPTEC is a trademark, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

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GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6.
This document is only current as of the last updated date stated below and is valid only for use in the Canada. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2024-06-21