Thrie-beam guardrail is the taller, three-wave version of the standard W-beam. Its extra corrugation and greater section depth give it more stiffness and containment height, so it is specified where a standard W-beam would deflect too far — bridges, ramps, high-risk curves and transitions. SinoBarrier rolls thrie-beam in-house to AASHTO M180 and supplies it as a complete crash-tested system.
Thrie-beam specifications
| Parameter | Standard value |
|---|---|
| Profile | Thrie-beam (three-wave corrugated) |
| Section width | 506 mm |
| Section depth | 83 mm |
| Steel thickness | 2.67 mm / 3.0 mm (per drawing) |
| Standard length | 3810 mm / 4130 mm (custom on request) |
| Base metal | Q235B or S355JR |
| Coating | Hot-dip galvanized, 550 g/m² minimum (AASHTO M180) |
When to specify thrie-beam over W-beam
- Bridge and overpass protection — where deflection space is constrained and a taller barrier is required.
- High-risk curves — where vehicles approach at speed and angle.
- Transitions — between a stiff bridge rail and a standard W-beam run.
- Median and narrow-shoulder sites — where more containment height is needed in less room.
Built and tested for high-risk sites
Thrie-beam sections are hot-dip galvanized to AASHTO M180 and the assembled barrier is crash-tested to MASH TL3 / TL4. Send your alignment drawings and we return a take-off with the correct post spacing and terminal treatment for each transition.