Description
These barrier transitions are also used to transition into Thrie-Beam installations for reasons such as reducing guardrail deflection and providing greater protection for heavier vehicles typically requiring Test Level 4 crash test performance.
Deployed for guard rails ending at bridges, concrete structures and crash cushions. Because guardrails are more flexible than the objects they attach to. Thus the need for a barrier transition section. Installed where there is a change in the deflection characteristics. For example between a guardrail and crash cushion or concrete structures.
Features
Typically a 6 metre arrangement consisting of a 2 metre W-Beam to Thrie-Beam transition rail followed by a 4 metre Thrie-Beam rail which may be nested or of 3.5mm BMT material, however, state road authorities do vary on the exact requirements and details. Check technical drawings* for further information.
Specifications
W-Beam to Thrie-Beam Transitions consist of W-Beam, Thrie-Beam, C-Block, C-Posts, Thrie-Beam Terminal Connector (optional) and associated hardware fixings.
Details and requirements such as spacing of posts, rail nesting, terminal connections and installation heights do vary across the different state road authorities. Check your local detail barrier transition drawing/s for further guidance.
Standards and Approvals
W-Beam and Thrie-Beam comply with the requirements of:
- AASHTO, AS/NZS 3845 – Road safety barrier systems.
- Approved for use by Australian State Road Authorities.