Uncoated stress-relieved low relaxation seven-ply strands for prestressed concrete are essential for high-strength reinforcement in various construction projects. Comprising seven twisted steel wires, these strands are tensioned before concrete is poured, creating a compressive force that enhances load-bearing capacity and reduces cracking. Their low relaxation property ensures the strands maintain consistent tension over time, boosting the durability and structural integrity of concrete. These strands are ideal for critical infrastructure projects like bridges, highways, and high-rise buildings, where long-term performance and reliability are crucial.

BIS certification is crucial for uncoated stress-relieved low relaxation seven-ply strands used in prestressed concrete. This certification ensures the strands meet stringent quality and safety standards set by the Bureau of Indian Standards, confirming they have the necessary tensile strength, durability, and low relaxation properties essential for effective prestressed concrete applications.

Indian Standard IS 14268: 1995

Under the latest Quality Control Order (QCO) from the Ministry of Steel, effective February 5, 2024, uncoated stress-relieved low relaxation seven-ply strands for prestressed concrete must conform to Indian Standard IS 14268:1995. This standard ensures the strands meet key quality and safety criteria, including tensile strength, durability, and low relaxation essential for prestressed concrete applications. Compliance with IS 14268:1995 guarantees precise manufacturing specifications, enhancing reliability and performance in critical infrastructure projects like bridges, highways, and buildings. Adhering to this standard is vital for manufacturers to meet regulatory guidelines, ensure product consistency, and build consumer trust in construction material quality and safety.

Tests

Key tests for IS 14268: 1995 As Uncoated Stress Relieved Low Relaxation Seven-ply Strand For Pre-stressed Concrete:

• Surface condition

• Dimensions of Indentations

• Strand

• Joints

• Treatment of Strand

• Workmanship and Finish

• Nominal diameter, tolerance, nominal cross-sectional area and nominal mass per unit length of strand.

• Straightness of Strand & Behavior During Cutting

• Breaking strength and 0.2 percent proof load

• Elongation

PROCESS FOR BIS ISI MARK CERTIFICATION