Admixture for enhancing high-quality surfaces and to reduce efflorescence

Product Description

OPTEC® EC-640 is used for the production of coloured concrete products from no-slump or semi-dry concrete. The main fields of application include the production of paver blocks, kerbstones or slabs.

Properties/Mode of Action

Surface-active substances effect a better dispersion of the cement particles. The concrete becomes more homogenous and easier to compact, thereby increasing both, green strength and ultimate strength. Close textured surfaces are promoted by the formation of slurries on the surface during vibration.

The integral hydrophobic components make the capillary pores water-repellent. The combined action of a denser concrete matrix, water repellency of capillary pores and plasticizing, the transport of moisture is reduced in the capillaries. Thus, the dissolved calcium hydroxide can only migrate in small quantities to the surface resulting in a reduced tendency to effloresce.

Finished products are more uniform and more intense in colours.

Dosage and Use

OPTEC® EC-640 is added with the gauging water, or to the readymix.

The concrete should be run as moist as possible in the block making machine in order to even increase the effect of OPTEC® EC-640

Special Information

Preliminary tests according to official national standards are always required before use!

Typical Properties

Effective component Surfactants
Form Liquid
Colour Dark brown
Density 1.01 ± 0.01 g/cm3
Freezing point Approx. 0OC
pH-value 10.0 ± 1
Storage Keep well closed in original containers. Keep well closed. Protect from excessive heat and frost.
Recommended dosage 3–4 ml/kg CEM Approx. 0.3–0.4 % of CEM
Delivery form 1010 kg containers; 200 kg drums; 23 kg cans
Physiological effect May irritate skin and eyes; see MSDS.
Shelf-life Approx. 12 month in closed original containers


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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 Applied Technologies (UK) Ltd, Gate St, Dukinfield SK16 4RU.

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Alpharetta, GA 30009, USA
GCP Applied Technologies (UK) Ltd, 487-488 Ipswich Road, Slough, SL1 4EP
This document is only current as of the last updated date stated below and is valid only for use in the United Kingdom. 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.uk. 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: 2022-11-24