A 4-inch thick fibrous concrete was placed on an old asphaltic concrete in 20 ft. wide lanes with sawed joints every 50 feet. All joints were filled with premolded neoprene joint filler. The outer strips of concrete were tied across the joint with tie bars. The interior slabs were not tied. The mix used here consisted of 8 ingredients: fibers (round wires made from rejected brass coated wire used in automobile tires) comprising about 1-1/2 percent of the total mix; cement (5-1/2 sacks of type I); fly ash (replaced 3 sacks of cement and provided pozzolanic action); water (35 gals.); coarse aggregate (rounded aggregate of one size); sand; air entrainment agent to obtain about 4 percent air; and set retarder. The introduction of the fibers in the direction of the conveyor belt carrying other materials and at sufficient speed to prevent tumbling was important. It was also important that fibers be introduced into the mixer at a relatively high speed. Details are given of external vibration, flexure tests, shrinkage of the concrete, and the mix design. Questions which have been raised and which must be answered prior to initiating a full scale project are listed.

  • Corporate Authors:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Gay, L H
    • Hawley, J C
    • Lindsay, W J
  • Publication Date: 1976-4

Media Info

  • Features: Photos;
  • Pagination: p. 53-65
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00149794
  • Record Type: Publication
  • Files: TRIS, USDOT
  • Created Date: Apr 13 1977 12:00AM