High Range Water Reducing Admixture (Retarding Type)

Product Description

DARACEM 921 is a versatile High-Range Water Reducer of Retarding type designed to cover several concrete applications, under normal to very high ambient temperatures without severely extending the set time of the concrete.

DARACEM 921 can specifically be used in concrete mixes containing cements or other SCMs, which record delayed set times with other conventional retarding type admixtures evenwhen desired slump retentions are not achieved.

DARACEM 921 is based on specially selected polymeric sulphonate materials and is a powerful deflocculant.

Depending on the addition rate, DARACEM 921 conforms to IS 9103, Type A, F, D and G materials of ASTM designation C 494, complies with EN934 Part 2.

Typical Properties

Appearance Dark brown liquid
Chloride Content NIL

Method Of Use

DARACEM 921 is supplied ready for use. It is a versatile, high performance product that can be used in a wide variety of applications.

When producing readymixed concrete It should be added in its supplied form with part of the batching water, after the addition of the cementitious component.


  • DARACEM 921 yields exceptional ultimate compressive strength over a wide range of cement contents
  • Imparts excellent and high water reduction
  • Exhibits very limited and predictable retardation characteristics
  • Compatible with GGBF Slag and PFA concretes
  • Can produce highly workable, self-levelling concrete when used at increased dosage
  • Aids cohesion of concrete
  • Multi-role capabilities

Addition Rates


  • 300 ml -1700 ml per 100 kg cement
  • 0.30% -1.70% (v/w) by wt. of cement

As a guide to these trials, an addition level of 0.3-1.7 % DARACEM 921 volume by weight of cement is recommended.

For advice and assistance with trials we recommend that you consult GCP Applied Technologies.

As with most products of this type the magnitude of the effect obtained with DARACEM 921, is governed by the quantity of product used, water-cement ratio, and the specific nature of the concrete and constituent materials.

It is necessary, therefore, to assess performance under site conditions using actual materials to determine optimum performance and dosage and effect on both plastic and hardened concrete properties such as cohesiveness, workability retention, setting characteristics, rate of early strength gain, ultimate strength and shrinkage where these are of importance.

Technical Service

Our Technical Service department of GCP Applied Technologies is available to assist you in the correct use of our performance chemicals.

Compatibility with Other Admixtures

DARACEM 921 should not be premixed under any circumstances with other admixtures. The performance of the product will be affected by the presence of other chemicals and we recommend that GCP be consulted in such circumstances.

Effects of Overdosing

The effects of overdosing DARACEM 921 are a function of the degree of overdose.

When producing high workability concrete, overdosing will increase the level of workability and may induce the onset of segregation.

Depending on the extent of the overdose, an increase in the setting time may also occur, especially in low temperatures and/or when employing sulphate resisting cement or cement replacement materials.

In any situation where overdosing is suspected, a careful inspection of the concrete in its plastic state should be conducted. Particular attention should be paid to consistency and cohesiveness, prior to a decision on the suitability of the concrete for the particular application.


It is preferable that DARACEM 921 should be introduced into the mixer by means of independent automatic dispensing equipment.

Equipment or advice on dispensing can be obtained from GCP Applied Technologies.

Health and Safety

For further information on Health and Safety matters regarding this product we recommend that you consult the relevant Safety Data Sheet from GCP Applied Technologies.


DARACEM 921 is supplied in 200 litre non-returnable drums. Alternatively, 1,000 litre totes and bulk deliveries can be arranged.


DARACEM 921 should preferably be stored away from extremes of cold or heat. The product should be kept in shaded storage at all times.

Storage Life in Manufacturer’s Drums:

12 months from date of manufacture.

Storage Life in Bulk Storage:

12 months from date of delivery.

gcpat.in | India customer service: +91 124 4885915

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.

DARACEM 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.

© Copyright 2016 GCP Applied Technologies Inc. All rights reserved.

GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140 USA.

90/2, Meppur Thangal Road, (Behind motel Highway), Madavillagam Village, Thirumazhisai, Tiruvalluvar Dt, Chennai- 602 103.India

This document is only current as of the last updated date stated below and is valid only for use in India. 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.in. 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: 2018-11-30