New Specification for Twisted Steel Micro Reinforcement for Concrete
1. Scope
This specification covers minimum requirements for twisted micro reinforcement for concrete. Twisted steel micro reinforcement is a steel rod or wire with a non-circular section that shall be twisted at least one time (360 degrees) about its own axis. Used as discontinuous reinforcement, the product is typically small enough to be mixed in large numbers into the concrete before placement.
The proposed standard covers specific mechanical properties and measurements that differ from requirements for fiber reinforced concrete and are not covered in ASTM A820/A820M. Properties such as twist pitch, number of faces and perimeter are required to compute bond properties. A paper by the original inventor of the technology is referenced that explains these principles.