Heavy-duty road grates for heavy vehicles

What they are

Heavy-duty road grates are welded steel grates built for pavements that carry trucks, forklifts, straddle carriers and other heavy plant. Compared with a standard steel drainage grate, they use deeper and thicker bearing bars at closer centres, a heavier frame angle or built-up frame, more anchor lugs and positive locking so that braking and turning wheels cannot lift or shift the grate. The frame is cast into a reinforced concrete surround that spreads the load into the pavement.

World Steel fabricates these grates in the same plant and to the same welding procedures as our heavy-duty grating for industrial floors. Typical uses are container terminals and wharves, freight and logistics yards, industrial estate roads, fuel and transport depots and mining haul roads, where cast items are difficult to source in the size required or where a project wants all drainage steelwork in one package.

Load classes covered

The values are the class test loads, not working wheel loads. For port and mining plant the designer often checks the grate for the actual vehicle wheel or axle load and contact area as well as the class – we work to whichever is the more onerous design given on the drawings.

Design and compliance

The grate is designed as a series of bearing bars spanning the clear opening, with cross bars and edge bars distributing the wheel load. Bar depth is governed by bending and deflection, while frame and anchorage design must resist both vertical load and horizontal braking forces. World Steel prepares calculations or checks the client's design for the specified class, sizes the welds, and produces shop drawings in Tekla. Test evidence for a class – where an authority requires it – is specific to the design and is agreed and witnessed in the contract; we do not claim road-authority prequalification or third-party approval unless it has been obtained for that design.

Anchorage to concrete is checked to AS 5216, EN 1992-4 or ACI 318 Chapter 17. Welding follows AS/NZS 1554.1, AWS D1.1 or EN ISO 3834-2, and coatings are applied by qualified galvanisers to AS/NZS 4680, ASTM A123 or EN ISO 1461. Our design team can coordinate frame details with the pavement engineer.

Fabrication at World Steel

• Deep bearing bars and frame plates are CNC cut, notched and welded in jigs for consistent seats.
• Frames can be angle, channel or built-up plate sections with anchor lugs or studs at close centres.
• Locking is by countersunk bolts into tapped frame bosses or by locking bars, keeping the top surface flush.
• Every grate is trial-fitted to its frame, marked with location and class, galvanised as a pair and checked again.
• Heavy items are packed on steel skids for crane handling; see packing and shipping.

Installation and site notes

Heavy-duty frames must be fully bedded – voids under the seat flange are the most common cause of rocking, noise and early failure. Brace frames during the pour, compact concrete thoroughly around the anchor lugs and keep grates in place until curing is complete. Tighten locking bolts to the specified torque and recheck after the first period of traffic. Inspect grates during routine pavement maintenance and repair any zinc damage with zinc-rich paint. Consult our foundation interface notes for cast-in tolerances.

Selecting and specifying

Please send the load class or design vehicle, clear openings and depth limits, the pavement and concrete detail, the locking requirement and any authority standard drawing. For drainage lines along wharves and yards we can also supply matching trench covers and pit covers so the whole drainage package arrives from one fabricator.