Custom Prefabricated Steel Truss Bridge Project Delivered for Southeast Asia Valley Transportation

Guoyu Steel supplied a full-set prefabricated steel truss bridge for valley traffic. ISO standard 3-coat anti-rust paint system, factory prefabrication, fast site installation, long service life for heavy load transport.

Project Overview

This custom steel truss bridge project is designed for a mountainous valley region in Southeast Asia, to solve the transportation barrier between farm zones and the main highway. The client required a heavy-load, low-maintenance steel bridge, capable of supporting farm trucks and heavy cargo vehicles, adapting to humid, high-rainfall valley corrosive environment. Guoyu Steel Structure took full responsibility for engineering design, steel fabrication, anti-corrosion coating, factory pre-assembly, container packing and technical erection guidance.

Core Project Data

• Bridge Type: Steel truss girder bridge
• Total span: 42m single span
• Width: 7.2m, two-way vehicle passage
• Total steel weight: 128 tons
• Design load: 30-ton vehicle load, comply with AASHTO highway standard
• Service life: 15–20 years with our complete 3-layer anti-corrosion coating
• Environment: High humidity, frequent rainfall, valley atmospheric corrosion (C3 corrosion grade, ISO 12944)
• Production cycle: 65 days factory fabrication
• On-site installation time: 10 days (only bolt assembly, no heavy on-site welding required)

Material & Fabrication Details

1. Main Steel Material Main truss members use Q355B high strength structural steel. All raw steel plates and sections pass material inspection, with MTC (Material Test Certificate) provided for every batch. CNC plasma cutting and robotic automatic welding are applied for all components. Welding joints are inspected by ultrasonic non-destructive testing (UT), to eliminate internal welding defects. All bridge segments are prefabricated and pre-assembled fully inside our factory workshop before shipment. We carry out trial assembly to check dimensional tolerance, bolt hole alignment and connection fit, guaranteeing seamless assembly on-site.
2. Anti-corrosion Coating System (ISO 12944 C3 standard, same paint system as your warehouse projects)

• Step 1: Surface blasting treatment to Sa2.5 grade, remove rust, oil and oxide scale
• Primer: Epoxy zinc-rich primer, film thickness 80μm
• Intermediate coat: Epoxy micaceous iron oxide paint, film thickness 100μm
• Topcoat: Polyurethane finish paint, film thickness 80μm Total dry film thickness: 260μm. This three-coat system provides long-term protection against moisture, rain and atmospheric corrosion, suitable for humid tropical valley conditions.

Construction & Delivery

All bridge truss segments are split into modular units for sea container shipment. After arrival at the port, the components are transported to the mountain valley site. Since all welding work is finished inside Guoyu factory, field workers only use high-strength bolts to connect prefabricated segments. This greatly cuts down site work duration and construction risk, also reduces environmental disturbance to the valley. Our technical team provides remote construction guidance, installation drawings and video tutorials for local builders.

Project Value & Client Feedback

Before the bridge was built, local farm products had to take a long detour. After completion, the 42m steel truss bridge directly connects the agricultural zone and main road, cutting transport time significantly. The client chose Guoyu because of our proven anti-rust coating technology and prefabricated steel manufacturing capacity. The modular design saves construction cost and minimizes future maintenance work.

Key Advantages of Guoyu Steel Bridge Solution

✅ Custom design according to local terrain, load and seismic requirement

✅ Full factory fabrication & pre-assembly, fast on-site erection

✅ ISO 12944 certified 3-layer anti-corrosion coating

✅ Complete test reports & certification documents for export

✅ Technical support for installation, after-sales maintenance guidance

✅ Suitable for farm access road, river crossing, industrial park, mining area bridges

CTA: Contact Guoyu Steel Structure to get your custom steel bridge design and factory quotation.