OPTEC® EC-978 Data Sheet

Color enhancing and efflorescence control admixture

Product Description

OPTEC® EC-978 admixture provides color enhancement and efflorescence control to the concrete roof tile industry. It is formulated as a ready-to-use admixture to aid the extrusion process and enhance the quality and appearance of concrete roof tile.

Product Uses

OPTEC® EC-978 admixture is especially designed for the efficient production of concrete roof tile. However, it can also be used in other manufactured concrete products such as architectural concrete masonry units and hardscape concrete products such as segmental retaining wall units and pavers. OPTEC® EC-978 improves color, via reduced efflorescence on concrete roof tile.

Product Advantages

  • Improves cement and pigment dispersion

  • Minimizes efflorescence

  • Enhances color

  • Aids extrusion process

  • Lowers absorption

  • Improves compressive strengths

Product Function

OPTEC® EC-978 admixture interacts with the cement and pigment and helps to uniformly disperse them in the mixture. OPTEC® EC-978 also lubricates the mixture aiding the roof tile extrusion process.

OPTEC® EC-978 reacts with the hydrating cement to produce a hard, less permeable surface and helps inhibit the formation of unsightly efflorescence on the surface of the concrete roof tile.

OPTEC® EC-978 may allow for a reduction of acrylic coatings used to protect the surface of the concrete roof tile. But, testing with local materials, production equipment and storage conditions is necessary to determine whether the acrylic coating can be reduced.

Application Information

Addition Rates

OPTEC® EC-978 admixture is generally used at a rate of 6–12 oz/ cwt (400–800 mL/100 kg) of cementitious materials including fly ash and other pozzolans. The addition rate is dependent upon the specific materials used and the desired end properties.

OPTEC® EC-978 should be added separately to the mix after the initial wetting of the cement and before or with the addition of the final mix water. Once OPTEC® EC-978 is batched, it should be mixed for a minimum of one minute, but preferably two minutes. Mix times of less than one minute should be avoided. Never add
OPTEC® EC-978 to dry cement.


OPTEC® EC-978 is compatible with other GCP admixtures. When multiple admixtures are used however, they must be added separately to the concrete mixture. Variables such as cementitious content, aggregate gradations, processing equipment, and curing conditions may have an impact on the effectiveness of OPTEC® EC-978. Testing with local materials and production equipment is necessary to determine the end results. Consult your GCP Masonry Products representative for more information.

Dispensing Equipment

OPTEC® EC-978 can be dispensed using conventional air diaphragm pump systems. For further information, contact your local GCP Masonry Products representative.


OPTEC® EC-978 is available in 55 U.S. gallon (208 L) drums, 275 U.S. gallon (1,040 L) returnable totes, and bulk. OPTEC® EC-978 weighs approximately 8.2 lbs/gallon (3.7 kg).

Health and Safety

All precautions defined on the SDS (Safety Data Sheet) for OPTEC® EC-978 must be followed.


OPTEC® EC-978 must be protected from freezing at temperatures of  32°F (0°C) and below, as the admixture is not usable once frozen.  Mechanical agitation may be required when stored for a period greater than 30 days.


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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 our conditions 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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This document is only current as of the last updated date stated below and is valid only for use in the United States. 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: 2023-06-28