STRUX® 85/50 Synthetic Macro-Fiber

Synthetic Macro Fiber for reinforcement of concrete

Product Description

STRUX® 85/50 synthetic macro fibers are a unique form of high strength, high modulus synthetic macro reinforcement that is evenly distributed throughout the concrete matrix. It consists of synthetic macro fibers 50 mm (2 in.) in length with an aspect ratio of 85 that have specifically been designed to ensure ease of use and rapid dispersion in concrete. STRUX® 85/50 is used in concrete to improve the material properties including toughness (post crack energy absorption), impact and fatigue resistance, residual strength and durability.

Compliance and Certification

  • ASTM C1116 / C1116M, Standard Specification for Fiber-Reinforced Concrete, Type III Synthetic Fiber-Reinforced Concrete
  • ASTM D7508 / D7508M, Standard Specification for Polyolefin Chopped Strands for Use in Concrete
  • ANSI/SDI C-2017, Composite Steel Floor Deck Slabs (Section 2.4.B.15.a.3)
  • CSA B66-16, Design, material and manufacturing requirements for prefabricated septic tanks and sewage holding tanks

Product Advantages

STRUX® 85/50 macro fibers have been designed to:

  • Eliminates the need for welded wire reinforcement (WWR) and small diameter bars used as secondary reinforcement
  • Enhances safety by eliminating handling of steel fibers, welded wire reinforcement and rebar
  • Improved durability, ductility, energy absorption, shatter resistance, fatigue resistance and flexural toughness
  • Improves control of both plastic and drying shrinkage
  • Quick, easy and safe application; arrives at the jobsite mixed into the concrete and ready to place
  • Savings from reduced labor, material and storage costs and shorter construction time compared to secondary reinforcement
  • Easily pumped; reduces wear on pump equipment associated with steel fibers
  • Reduces shotcrete rebound and improves cohesion

Primary Applications

STRUX® 85/50 macro fibers may be used in a variety of ready mix, precast and shotcrete applications including: bridge decks, overlays, whitetopping, pipes, vaults, septic tanks, tunnel linings, slope stabilization, and swimming pools.

When added to shotcrete and concrete, the primary benefit of STRUX® 85/50 macro fiber is a significant improvement in flexural toughness.

Addition Rates

STRUX® 85/50 macro fibers addition rates are dependent on the specific application and desired properties and will typically vary between 5 to 15 lb/yd3 (3 to 9 kg/m3). Please consult your GCP Applied Technologies sales representative for the proper addition rate of STRUX® 85/50 macro fibers for your application.  Always consult local building codes.

Guidelines for Usage and Compatibility with Other Admixtures

The utilization of STRUX 85/50 macro fibers generally requires the use of a superplasticizer such as ADVA® to restore the required workability to fiber reinforced concrete. In addition, slight increases in fine aggregate contents may be needed. STRUX® 85/50 may be added to concrete at any point during the batching or mixing process. STRUX® 85/50 should be added at a maximum rate of one bag every 30 seconds. After fiber addition the concrete should be mixed at the recommended mixing speed for a minimum of 70 revolutions to ensure adequate fiber dispersion. Please contact your GCP representative with any questions.

STRUX® 85/50 macro fibers are compatible with all GCP admixtures. Their action in concrete is mechanical and will not affect the hydration process of the cement or the compressive strength. Each liquid admixture should be added separately to the concrete mix.

STRUX® 85/50 Macro Fibers Physical Properties

Specific gravity 0.92 
Absorption None 
Modulus of elasticity 1,235 ksi (8.5 GPa) 
Tensile strength 81 ksi (560 MPa) 
Melting point 320°F (160°C) 
Ignition point 1,050°F (570°C) 
Alkali, acid & salt resistance High 
Material 100% virgin polypropylene and polyethylene blend
Electrical and Thermal Conductivity Low
Nominal Length 2 in. (51 mm)
Nominal Aspect Ratio 85
Nominal Equivalent Diameter 0.023 in. (0.59 mm)
Nominal Fiber Count 37,500 per lb (82,600 per kg)


STRUX® 85/50 macro fibers are available in 2.3 kg (5 lb) bags.

Safety and Handling:

Read and understand the product label and Safety Data Sheet (SDS). All users should acquaint themselves with this information prior to working with the products and follow the precautionary statements. SDSs can be obtained by contacting your local GCP representative or office.

U.S. Patent No. 6,569,525
U.S. Patent No. 6,569,526
U.S. Patent No. 6,758,897
U.S. Patent No.  6,863,969 | 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.

ADVA, MIRA and STRUX 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.

© Copyright 2020 GCP Applied Technologies Inc. All rights reserved.

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 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