RDA® Additive for Cement Aid

Additive for Cement Aid

Product Description

RDA® is a chemical additive to be interground during the manufacture of Portland and blended cements to retard the initial and final set of cement pastes and mortars.

RDA® is based on an aqueous solution of hydroxylated organic compounds.

Physical Properties


Appearance: brown or blue liquid

Density (g/l): 1200-1250

pH: 6.5-7.5

Recommended Addition Rate

According to GCP experience the addition rate of RDA® is in the range of 250-1000 g/t of treated cement. However the optimum addition rate of RDA® depends upon the degree of retardation required under job condition. Longer setting times or higher temperatures will require higher addition rates.

Deviation from the optimum cannot guarantee the expected results.


RDA® controls effectively the setting process and permits significant extension of the board life.

Typical Application

RDA® is used wherever a delay in setting time will insure sufficient delivery, placement, vibration or compaction time.

How to Use

RDA® should be added on to the feed belt or injected into the mill. For an accurate proportioning of RDA® a volumetric metering pump is suitable.

GCP can advise on the most appropriate dosing equipment.

Specification Compliance

Approved for use under ASTM C465 specifications as a nonharmful processing addition. RDA® has been thoroughly tested and is widely used in the cement industry.

Packaging and Handling

RDA® is supplied in 210 liter drums, in 1000 liter plastic containers or bulk.

Shelf life is 24 months if stored in manufacturer’s containers.

Storage Precautions

RDA® does not require particular precaution for the storage. RDA® has to be protected from freezing.

For tanks and containers placed outside a heating system or a re-mixing device is suitable. It is also better to insulate exposed pipelines.

GCP personnel can help in designing the best system.

Handling Precautions

RDA® does not require particular precaution for health and safety. Please refer to the SDS (Safety Data Sheet).

Accidental release or spillage is to be absorbed with an inert material, such as sand or sawdust.

Tanks and containers can be cleaned with water.

ca.gcpat.com | North America customer service: 1-877-4AD-MIX (1-877-423-6491)

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: 2020-07-09