Do You Know the Differences between HDPE Coated Prestressed Steel Strand and Unbonded Prestressed Steel Strand?

Both HDPE coated prestressed steel strand and unbonded steel strand all have the HDPE sheath, which offering excellent corrosion resistance and have wide range of applications. However, many customers often cannot distinguish between those two products. Therefore, this article will compare them from multiple perspectives to help you better understand these two products. If you have any questions, please contact us at any time via the phone number or email address listed on our official website. The specific differences are as follows:

1. Structural Composition

- HDPE Coated Prestressed Steel Strand: Its core structure consists of a layer of HDPE material directly wrapped around the surface of the steel strand. Some products may also include anti-corrosion grease for enhanced protection.

- Unbonded Prestressed Steel Strand: It employs a "double-layer protection" structure. First, anti-corrosion grease or paraffin is applied to the surface of the ordinary prestressed steel strand, followed by the HDPE sheath. Both the anti-corrosion grease layer and the HDPE sheath are essential components.

2. Concrete Bonding Performance

- HDPE Coated Prestressed Steel Strands: It offers greater adaptability and can be flexibly applied to bonded or unbonded prestressed systems according to project requirements.

- Unbonded Prestressed Steel Strands: Characterized by distinct properties, they do not bond with the surrounding concrete throughout the entire process. During operation, longitudinal relative sliding between the prestressing tendons and concrete is permitted, and the prestressing force is entirely transferred to the concrete structure through the anchorages.

3. Construction Process

- HDPE Coated Prestressed Steel Strand: The application scenario determines the process. When used in bonded systems, the steps of pre-drilling, threading, and grouting must be completed sequentially. When used in unbonded systems, the grouting step can be omitted.

- Unbonded Prestressed Steel Strand: The construction process is simpler. No pre-drilling is required. It can be laid directly inside the formwork like ordinary steel bars. After pouring concrete, tensioning and anchoring can be carried out once the strand reaches the design strength.

4. Application Scenarios

- HDPE Coated Prestressed Steel Strand: Its core advantage lies in corrosion resistance, making it widely applicable to various prestressed projects with high corrosion resistance requirements, such as coastal areas and damp underground environments.

- Unbonded Prestressed Steel Strand: Balancing corrosion resistance and structural adaptability, it is suitable for large-span stadiums, exhibition halls, and other locations with high requirements for deformation and flexibility, as well as structures requiring seepage prevention and complex maintenance, such as water tanks and sewage treatment ponds.

5. Performance Characteristics

- HDPE Coated Prestressed Steel Strand: Its core highlight is the outstanding corrosion resistance. HDPE material effectively isolates it from various corrosive media, ensuring the service life of the steel strand.

- Unbonded Prestressed Steel Strand: In addition to corrosion resistance, it also boasts advantages such as low prestress loss and excellent seismic performance—the anti-corrosion grease layer reduces tension friction loss. Even when seismic loads cause significant structural displacement, the sliding steel strands remain under tension, resulting the stable stress changes.

In Summary, those two products can be easily distinguished by their structure, bonding performance, construction process, application scenarios, and core characteristics. You can also choose the appropriate steel strand type based on the specific application environment, and it can help you complete your project faster. For product inquiries, if you needs coordination or price requests, please feel free to contact us. Please visit our official website (www.yxmaterial.com) for product details. We're looking forward to cooperating with you in future!