Water-reducing and retarding ASTM C494 Type B and D

Product Description

ZYLA® R is a ready-to-use aqueous solution of organic compounds specifically designed as an admixture for Portland cement concrete. The ingredients are factory pre-mixed in exact proportions under strict quality control to provide uniform results. One gallon weighs approximately 8.9 lbs (one liter weighs approximately 1.07 kg).

Product Advantages

  • No impact on concrete air content
  • Better control of water reduction and setting times as compared to traditional lignin-based water reducers
  • Synergistic performance of polycarboxylate-based mid-range and high-range water reducers, which includes water reduction and concrete strength and air control
  • In the hardened state, improves the compressive and flexural strengths at all ages of concrete versus traditional lignin-based water reducers
  • Linear set retardation with increasing addition rates

Product Uses

Set Retarder

ZYLA® R is used to retard the initial and final set of concrete. At the usual addition rate of 3 to 5 fl oz/100 lbs (195 to 325 mL/100 kg) cementitious it will extend the initial setting time of Portland cement concrete by approximately 2 to 3 hours at 70°F (21°C). It is specifically designed to be a linear set retarder with increasing dosage rate. See Table 1. ZYLA® R is used wherever a delay in setting time will insure sufficient delivery, placement, vibration or compaction time. It may be used in all types of concrete.

Water-Reducing Properties

Along with set retardation, ZYLA® R typically provides 5% water reduction in a concrete mix. This water-reducing action of ZYLA® R produces greater plasticity and workability in the fresh concrete and the strength and permeability of the hardened concrete are measurably improved. ZYLA® R is designed for use on jobs where high temperatures or extended setting times are the prime factors. It is recommended only when the primary purpose is to delay and control the setting time of concrete.

Concrete Workability

Although ZYLA® R is formulated primarily as a concrete set retarder for all types of concrete, it is also used to aid placing of low-slump concrete such as curb and gutter, paving and pervious concrete. It reduces the amount of hand finishing required in these applications and makes it easier to discharge from the truck, while better controlling the setting time.

Addition Rates

Addition rates of ZYLA® R as an ASTM C494 Type D retarder, may be 2 to 12 oz/100 lbs (130 to 780 mL/100 kg) of cementitious. Proper dosage rate selection can only be achieved through pretesting before a project starts, and as job and environmental conditions change. Consult your local GCP Applied Technologies admixture representative.

Compatibility with Other Admixtures and Batch Sequencing

ZYLA® R is compatible with most GCP admixtures as long as they are added separately to the concrete mix, usually through the water holding tank discharge line. In general, it is recommended that ZYLA® R be added to the concrete mix near the end of the batch sequence for optimum performance. Different sequencing may be used if local testing shows better performance. Please see GCP Technical Bulletin TB-0110, Admixture Dispenser Discharge Line Location and Sequencing for Concrete Batching Operations for further recommendations.

Pretesting of the concrete mix should be performed before use, as conditions and materials change in order to assure compatibility, and to optimize dosage rates, addition times in the batch sequencing and concrete performance. For concrete that requires air entrainment, the use of an ASTM C260 air-entraining agent (such as Daravair® or Darex® product lines) is recommended to provide suitable air void parameters for freeze-thaw resistance. Please consult your GCP Applied Technologies representative for guidance.

Dispensing Equipment

A complete line of accurate, automatic dispensing equipment is available. ZYLA® R should be introduced to the mix through the water tank pipe or through a separate hose.

Packaging & Handling

ZYLA® R is available in bulk, delivered by metered tank trucks, totes and drums.

ZYLA® R will freeze, but will return to full effectiveness after thawing and thorough mechanical agitation.


Concrete shall be designed in accordance with Standard Recommended Practice for Selecting Proportions for Concrete, ACI 211.1.

The set-retarding/water-reducing admixture shall comply with ASTM Designation C494, Type D admixture, and shall be ZYLA® R, as manufactured by GCP Applied Technologies, or equal. Certification of compliance shall be made available on request. It shall be used in strict accordance with the manufacturers’ recommendations.

The addition rate shall be adjusted to produce the specified retardation of the concrete mix at all temperatures.

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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.

ZYLA, DARAVAIR and DAREX are trademarks, 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 Inc., 2325 Lakeview Parkway, Suite 475, Alpharetta, GA 30009, USA
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