Work Item
ASTM WK86788

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.


acceptance testing; classification; twisted steel micro reinforcement, fiber-reinforced concrete; tensile strength; testing procedures


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.

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: A01.05

Committee: A01

Staff Manager: W Scott Orthey

Work Item Status

Date Initiated: 06-13-2023

Technical Contact: Luke Pinkerton