Uncoated PC Strand – Bare Prestressed Concrete Steel Strand for Post-Tensioning & Pre-Tensioning

Low-Relaxation Bare PC Strand – Reliable Tensile Performance for Bridge, Building & Precast Concrete Applications

Product Introduction

The primary raw material for steel strands (Uncoated PC strands) is Grade 82B high-carbon steel. Renowned for its exceptional tensile strength, excellent cold-forming properties, and cost-effectiveness, it has become the most widely used choice in prestressed concrete applications such as buildings, bridges, and water conservancy projects. The uncoated PC strand features a seven-wire configuration (1×7) with low-relaxation properties, ensuring stable and long-lasting prestress retention. It is available in various diameters (9.5mm, 12.7mm, 15.2mm, 15.7mm, 17.8mm, and 21.8mm) and strength grades (1860MPa, 1960MPa) to meet diverse engineering requirements.

Key Features & Advantages

🏭 Raw Material: Grade 82B high-carbon steel for exceptional tensile strength and cold-forming properties.

📉 Low Relaxation: Relaxation rate ≤ 2.5% after 1000 hours, ensuring minimal prestress loss over time.

🔧 Seven-Wire Configuration: Standard 1×7 construction with smooth surface for reliable bond with concrete.

💪 High Tensile Strength: Available in 1860MPa and 1960MPa strength grades.

📏 Wide Diameter Range: Available in 9.5mm, 12.7mm, 15.2mm, 15.7mm, 17.8mm, and 21.8mm.

🔄 Excellent Fatigue Resistance: Withstands dynamic loads in bridges and heavy traffic structures.

💰 Cost-Effective: Grade 82B raw material offers excellent value for large-scale prestressed concrete projects.

📜 Compliant Standards: Manufactured to GB/T 5224 and international equivalents.

Ⅰ. Steel Strand Mechanical Property Parameters

Nominal Diameter (mm)	Nominal Area (mm²)	Tensile Strength (MPa)	Min Break Load (kN)	0.1% Proof Load (kN)	Elongation (%)	Relaxation (1000h, 70% load)
9.5	54.8	1860	102	87.7	≥3.5	≤2.5%
12.7	98.7	1860	184	158	≥3.5	≤2.5%
15.2	140	1860	260	224	≥3.5	≤2.5%
15.2	140	1960	274	236	≥3.5	≤2.5%
15.7	150	1860	279	240	≥3.5	≤2.5%
17.8	190	1860	353	304	≥3.5	≤2.5%
21.8	285	1770	505	434	≥3.5	≤2.5%

* All parameters for reference only. Custom specifications available upon request.

Ⅱ. Steel Strand Production Standards

Steel Strand Production Standards:

• GB/T 5224 – 2023: Steel Strands for Prestressed Concrete

• GB/T 25823 – 2010: Single-Wire Epoxy-Coated Prestressed Steel Strands

• JT/T 737 – 2009: Filled Epoxy-Coated Steel Strands

• GB/T 21073 – 2007: Epoxy-Coated Seven-Wire Prestressed Steel Strands

• GB/T 33363 – 2016: Prestressed Hot-Galvanized Steel Strands

Application

Uncoated PC strand is widely used as prestressing tendons in concrete structures requiring high tensile strength and low relaxation. Typical applications include:

Bridge Engineering: Used as prestressing tendons in post-tensioned box girders, T-beams, segmental bridges, and cable-stayed bridge stays.

Building Construction: Applied in post-tensioned floor slabs, transfer beams, foundations, and parking garages.

Precast Concrete Industry: Used in precast beams, hollow-core slabs, piles, railway sleepers, and concrete poles.

Water Conservancy: Applied in dam tendons, lock chambers, and hydraulic tunnel linings.

Ground Anchors & Soil Nailing: Provides tensile elements for slope stabilization, retaining walls, and deep excavation support.

Wind Power Towers: Anchors prestressing tendons in wind turbine towers for onshore and offshore projects.

Workshop

Our Manufacturing Base – Liuzhou Xuanqiao Prestressed Machinery Co., Ltd.

Located in Liuzhou, Guangxi – a key industrial hub for prestressed technology – our modern workshop covers over 10,000㎡. We operate CNC machining centers, automated assembly lines, and precision testing equipment to ensure consistent quality.

Every batch of raw material is inspected, and finished products (anchors, jacks, pumps, ducts) are tested in our in‑house laboratory for mechanical performance and pressure resistance. We are certified under ISO 9001:2015 and comply with FIP international standards.

Annual capacity: 6 million anchor holes and 1,000+ sets of hydraulic equipment. Our experienced technicians and engineers follow strict SOPs to guarantee reliability.

We maintain sufficient raw material inventory and finished goods for fast delivery. Continuous investment in equipment and training keeps us at the forefront of prestressed manufacturing – because a strong factory means reliable products and long‑term trust.