Which specification governs the quality of prestressing strand in concrete?

The specification that governs the quality of prestressing strand in concrete is ASTM A416. This standard specifically addresses the requirements for low-relaxation, high-strength steel strands that are intended for use in prestressing concrete applications. The ASTM A416 specification outlines the material properties, testing procedures, and performance criteria that these strands must meet to ensure their effectiveness and reliability in providing tension in prestressed concrete structures.

In the context of prestressing, the use of high-strength steel strands is crucial because they must withstand significant tensile forces while also being durable over time. ASTM A416 ensures that these strands have the necessary mechanical properties, including yield strength and elongation, which contribute to the overall performance and longevity of the prestressed concrete element.

The other standards listed do not pertain to prestressing strands. For example, ASTM C578 relates to rigid, cellular polystyrene thermal insulation. ASTM D1751 specifies joint fillers for concrete and asphalt pavements. ASTM C90 governs loadbearing concrete masonry units. Each of these standards serves a different purpose and does not specifically address the requirements for prestressing materials.