Welded rebar truss


Welded rebar truss in Pooladkaf Industrial Group

Truss is a rigid rectangular structure with straight members, the members of truss are connected with joints (hinges). Rebar truss is a prefabricated mesh of lower, upper and lateral (zigzag) tensile rebar welded or hooked together, providing sufficient stability for transportation and installation. Pooladkaf Industrial Group is the founder of floor block joist manufacturing in Fars Province and has played a significant role in promoting block joist floors. Until 1985, joists used in Iran were manually welded and manufactured. In 1985, Pooladkaf Industrial Group established Pooladkaf Company in Iran to manufacture trusses using machines; in this factory, first low carbon rebar are cold forged and spun in spools. The rebar are then automatically bent to shape by truss making machines and linked by electrical current and hydraulic welding systems. Finally, trusses are cut to desired sizes and packaged.

Descriptions of rebar truss:

  • Height: 7 to 30 centimeters
  • Length: 1 to 13 meters
  • Diameter: Lower and upper rebar from 7 to 14 millimeters and zigzag rebar from 4 to 6 millimeters
  • Minimum yield stress of rebar: 4200 kilograms per square centimeter
  • Weight of each meter of truss based on rebar diameter and height: 900 grams to 4 kilograms

Advantages of using rebar truss:

  • All components are point welded by automatic machines
  • Absolute order in all member of the truss in terms of rebar diameter, resistance, welding and length
  • High resilience in rebar used
  • Possibility of ordering it in desired lengths, avoiding waste by cutting and ease of transportation (ten thousand meters of truss in one trailer)
  • Vast range of truss height and rebar diameters
  • Reduced use of candles or jacks during construction due to the strength of trusses

Uses of rebar truss:

  • Fabrication of joists for joist block or light weight floors
  • Use in prefabricated concrete parts as stringer or for holding the meshes
  • Use in vertical and horizontal ties

Truss standards in Iran

  • In Iran, the Organization for State Management and Planning has set the standards for trusses and joists via two publications.
  • Publication 82 of the Organization for State Management and Planning, Deputy of Technical Affairs, 1385 Edition
  • Publication 94 of the Organization for State Management and Planning, Deputy of Technical Affairs, 1384 Edition
  • Subsequently, the Standard and Industrial Research Organization of Iran provided the 2909-1 standard of year 85 in two sections of “trusses” and “joists” used in joist block floors.