SINTA® F38 Data Sheet

Synthetic fiber for concrete ASTM C1116, ASTM C94 (formerly 1 1/2" Grace Fibers™ )

Product Description

SINTA® F38 synthetic fibers for concrete, are manufactured from 100% virgin polypropylene in collated, fibrillated form. Designed specifically for use in concrete, they are alkali resistant, non-absorptive and completely noncorrosive. Their use protects concrete from stresses which cause cracking while it is most vulnerable during the first 24 hours after placement. SINTA® F38 comply with ASTM Designation C1116, Standard Specification for Fiber-Reinforced Concrete and Shotcrete, Type III Synthetic Fiber-Reinforced Concrete or Shotcrete. They are available in  1.5 in. (37 mm) length.


SINTA® F38, at the appropriate dosage rate, may be used as an alternative to welded-wire reinforcement, depending on the application, to provide temperature and shrinkage crack control.

Specifically, such applications include but are not limited to, slabs on grade, pavements, overlays, sloped walls, pools, shotcrete, stucco, precast and prestressed products. It is suggested that this product be used in conjunction with properly compacted base materials and jointing in accordance with ACI guidelines and standards.

Product Advantages

  • Reduces plastic shrinkage cracking and improves durability
  • Protects concrete from stresses that cause cracking
  • Provides cost effective control of plastic shrinkage
  • Provides overall higher quality of concrete


SINTA® F38 uniformly distribute multi-dimensionally throughout the concrete mixture. The small fibrillated fibers mechanically lock in the fresh concrete matrix providing reinforcement for the mixture while its tensile strength is the weakest. This reinforcement reduces the formation of plastic shrinkage cracking that may otherwise permanently weaken the resulting concrete. The concrete permeability is decreased, while the surface characteristics, impact and toughness properties are improved. Together these effects work synergistically to produce a long-term better quality, more durable and serviceable concrete.

Addition Rates

SINTA® F38 may be added to concrete at any point during the batching or mixing process. SINTA® F38 may be added to the aggregate during weighing or charging, or to the central mixer or truck before, during, or after charging. The load must be mixed at high speed for 5 minutes, or 70 revolutions, after the addition of the SINTA® F38 to ensure uniform distribution. The standard range of addition for SINTA® F38 is ¾ to 3 lbs/yd3 (450 to 1800 g/m3) of concrete. Typically, 1½ lbs/yd3 (900 g/m3) of SINTA® F38 provides excellent results. Higher addition rates may be used to produce concrete when special properties are required.

Compatibility with Other Admixtures

SINTA® F38 are compatible with all GCP admixtures. Their action in concrete is purely mechanical and will not affect the hydration process. Each admixture should be added separately.

Packaging & Handling

SINTA® F38 are available in convenient Concrete-Ready® Bags which are added, unopened, to the truck drum or central mixer. The specially designed cellulose fiber bag disintegrates and disperses its contents of SINTA® F38, throughout the mix.


Fibers shall be 1.5 in. (38 mm) collated, fibrillated polypropylene fibers as supplied by GCP Applied Technologies, Cambridge, MA 02140. Required dosage rate shall be as specified by the design engineer or architect. SINTA® F38 shall be used in strict accordance with the supplier’s recommendations and within time as specified in ASTM C94. The fibers shall comply with ASTM Designation C1116 Type III 4.1.3 and with applicable building codes. Certification of compliance shall be made available on request. Standard ACI 302 procedures for placing, finishing and curing shall be followed when using SINTA® F38.


Building Codes

  • BOCA National Building Codes, SBCCI Standard Building Code, ICBO Uniform Building Code and all supplements as adopted by the Council of American Building Officials

Fire Classifications

  • Underwriters Laboratories (UL) on Series D700 and D800 metal deck assemblies

American Concrete Institute (ACI)

  • ACI 544 State of the Art Report of Fiber-Reinforced Concrete
  • ACI 302 Guide for Concrete Floor and Slab Construction

American Society of Testing and Materials (ASTM)

  • ASTM C1116 Standard Specification for Fiber-Reinforced Concrete and Shotcrete
  • ASTM C1579 Standard Test Method for Evaluating Plastic Shrinkage Cracking of Restrained Fiber Reinforced Concrete (Using a Steel Form Insert)
  • ASTM C94 Standard Specification for Ready-Mixed Concrete | North America Customer Service: +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.

SINTA 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 2018 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 United States. 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