ASTM International’s committee on steel, stainless steel, and related alloys (A01) is revising a steel reinforcement standard that could lead to savings in material and construction costs, as well as greater design efficiency.
Proposed revisions to the standard (A416/A416M, Specification for Low-Relaxation, Seven-Wire Steel Strand for Prestressed Concrete) will add three higher-strength grades (310, 325, and 340) to the specification, representing a 15-25% increase in minimum tensile strength. Requirements for the three grades of higher-strength strand will be included in the new annex.
“In the global engineering and construction industries, there is considerable interest in high-performance materials for use in concrete structures,” says ASTM member Taejin Hwang, who his chairing the task group that is revising the standard. “For steel reinforcement, the term ‘high-performance’ encompasses several desired attributes including corrosion resistance, toughness, weldability, strength, and more.”
Hwang, a senior researcher at Korea Testing Certification in Gunpo, South Korea, says that the higher strength strands being added to A416 are manufactured in Asia and are being used in the construction of bridges, storage tanks, and other structures.