A COMPARATIVE EVALUATION OF FIBER SHOTCRETES

This report presents a comparative evaluation of the performance characteristics of fiber shotcretes with four types of steel fibers. The fibers used were two types of collated fibers with deformed ends, straight fibers, and cut steel tire cord. Three different fiber concentrations were used at 0.6, 1.0, and 1.3 percent. The dry-process sanded mix shotcrete with an assumed water cement ratio of 0.46 and 5 percent entrapped air wa used in this investigation. Using a well established shotcreting company and quality equipment, and a nozzelman with 18 years of shotcreting experience, 336 test panels were made with 1 1/2 inch (38 mm) and 3 inch (76 mm) thicknesses. Test panels were shot in a raised vertical position against rigid plywood forms with open bottoms. Saw and core samples were made from the test panels and the following tests were conducted: cube compression test including unit weight, flexural test including load-deflection curves, impact test, shrinkage meaurements, and pulse velocity and dynamic modulus of elasticity tests. One major finding is that collated fibers with hooked ends could be effectively used in shotcreting and that they perform well. Excellent distribution of fibers was noted from the x-ray photos. All of the fibe shotcretes showed a tremendous ability to absorb impact loading; the hooked fibers showing a far superior ability than the straight fibers. The static flexural test shows tht an excellent end anchorage is established in the case of thee hooked fibers resulting in a high ductility of the shotcrete. For the three fiber concentrations used, only a slight increase was recorded in the properties of the hardened shotcretes.

• Supplemental Notes:
  • Prepared for the Bekaert Steel Wire Corporation.
• Corporate Authors:

  South Dakota School of Mines and Technology, Rapid City

  Department of Civil and Environmental Engineering, 500 East St Joseph Street
  Rapid City, SD  United States  57701
• Authors:
  • Ramakrishnar, V
  • Coyle, W V
  • Fowler, L J
  • Schrader, E K
• Publication Date: 1979-8

Media Info

• Pagination: 35 p.

Subject/Index Terms

• TRT Terms: Alternatives analysis; Compression tests; Concrete; Crash tests; Ductility; Fibers; Measurement; Modulus of elasticity; Performance; Shotcrete; Shrinkage; Water cement ratio; X rays
• Uncontrolled Terms: Comparative analysis
• Old TRIS Terms: Concrete shrinkage
• Subject Areas: Highways; Materials; Research;

Filing Info

• Accession Number: 00322258
• Record Type: Publication
• Report/Paper Numbers: Rpt SDSM&T-CBS 7902
• Files: TRIS
• Created Date: Jan 19 1981 12:00AM