High-range water-reducing admixture for shotcrete

Product Description

TYTRO® WR 158 is a polycarboxylate-based high-range water-reducing admixture specifically formulated to provide prolonged workability, excellent plasticity and extended slump life in underground shotcrete applications.

Featuring the latest in the polycarboxylate technology, TYTRO® WR 158 provides superior water reducing performance to shotcrete.

Manufactured under closely controlled conditions to provide uniform, predictable performance, GCP’s TYTRO® WR 158 contains no added chlorides and is formulated to comply with specifications for Chemical Admixtures for Concrete, ASTM Designation C494 as a Type A and F admixture.

Product Advantages

  • Efficient dosage rate – Produces high slump shotcrete at very low dosages
  • Operational flexibility – Prolonged workability
  • Improved pumpability – Improved consistency
  • Lower water-to-cementitious materials ratio – Enables designing shotcrete mix with higher strength and durability
  • Neutral impact on set time and air content
  • Consistent performance across cement chemistries


TYTRO® WR 158 is used in all shotcrete applications where it is desired to minimize the water-to-cementitious materials ratio yet maintaining workability, especially in the following applications:

  • Temporary and permanent rock support in tunnels
  • Underground rock support in mining
  • Slope stabilization

Addition Rates

The dosage of TYTRO® WR 158 can vary based on the mix design, cementitious content, water-to-cementitious materials ratio, aggregate gradations and slump required.

The dosage of TYTRO® WR 158 normally ranges between 0.8% and 1.5% by the total weight of cementitious materials. At a given water-to-cementitious materials ratio, the slump required for placement can be controlled by varying the addition rate. Should conditions require using more than the recommended addition rates, please consult your GCP representative.

GCP recommends that trials be performed with cement and aggregates under local conditions before use to assess and optimize dosage rates and performance.

Mixing & Dispensing

In general, it is recommended that TYTRO® WR 158 be added to the mix near the end of the batch sequence for optimum performance.

It is recommended that TYTRO® WR 158 be introduced into the mixer by means of automatic dispensing equipment. A range of equipment is available, and advice on supply and fitting is available from GCP on request.


TYTRO® WR 158 is available in bulk, totes and drums.



TYTRO® WR 158 should be stored at a temperature range of 2 °C to 35 °C.

If TYTRO® WR 158 freezes, it will return to full effectiveness after thawing and thorough mechanical agitation. It is recommended that your local GCP sales representative be consulted prior to the use of any products that may have been frozen. Performance tests should always be carried out prior to use.


TYTRO® WR 158 must be kept in closed plastic containers or closed tanks.

Shelf life

If stored in tightly closed original containers and under the above mentioned conditions, TYTRO® WR 158 has a shelf life of at least 12 months.

Please contact your local GCP sales representative regarding the suitability for use if the shelf life of TYTRO® WR 158 has been exceeded.

Health and Safety

Avoid eye and skin contact and wear rubber gloves and safety glasses when handling this product. If contact occurs, rinse with plenty of water and seek medical advice.

For further information, refer to the SDS (Safety Data Sheet) or contact your local GCP representative.


TYTRO® WR 158 is compatible with all GCP TYTRO® shotcrete admixtures.

GCP recommends that a suitable alkali-free set accelerator and a hydration control admixture be incorporated into the shotcrete mix to achieve the required strength performance and setting characteristics. TYTRO® SA series of high performance set accelerator along with TYTRO® HC series of hydration stabilizing admixtures are recommended for this purpose. For shotcrete requiring air entrainment, the use of TYTRO® AE series is recommended to provide desired air content and air-void system for resistance against freezing and thawing cycles.

Pretesting of the shotcrete mix should be performed before use and as conditions and materials change in order to ensure compatibility with other admixtures.

For use with other shotcrete admixtures systems, we recommend you contact GCP for further advice.


Form Liquid
Density (g/cm3) 1.06-1.10
pH (20 °C / 68 °F) 4.2-6.0
Chloride Content ≤500 ppm

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

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.

TYTRO 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 Inc., 2325 Lakeview Parkway, Suite 450, 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: 2023-06-29