BIS has introduced the IS 6006:2014 standard for uncoated stress-relieved strands used in prestressed concrete. Manufacturers must secure BIS certification to ensure their uncoated stress-relieved strands meet quality and compliance requirements. These strands, made of multiple steel wires twisted together, provide high-strength reinforcement by being tensioned before concrete is poured. Once the tension is released, they create a compressive force that enhances the concrete's load-bearing capacity and reduces cracking. This method is crucial for constructing durable structures like bridges, highways, and high-rise buildings. The stress-relieved process guarantees consistent mechanical properties for better performance and reliability in prestressed concrete applications.

Indian Standard IS 6006: 2014

Under the latest Quality Control Order (QCO) from the Ministry of Steel, effective February 5, 2024, uncoated stress-relieved strands for prestressed concrete must adhere to Indian Standard IS 6006: 2014. This standard outlines the key requirements for manufacturing and testing these strands, ensuring they meet high quality and safety standards. Compliance with IS 6006:2014 guarantees essential criteria such as tensile strength, ductility, and corrosion resistance, crucial for the durability and performance of prestressed concrete structures. Following this standard is vital for the reliability and structural integrity of infrastructure projects, including bridges and buildings, ensuring safety and long-term performance in construction.

Tests

Key tests for IS 6006: 2014 As Uncoated stress relieved strand for Pre-stressed concrete:

• Strand

• Size and Designation a) Nominal diameter b) Nominal cross-sectional area c) Nominal mass of strand

• Breaking strength

• Proof load

• Elongation

PROCESS FOR BIS ISI MARK CERTIFICATION