Please note: The use of recycled asphalt for crossovers is not supported by the Shire.

Boxing out

Where necessary, the site of the crossover should first be cleared of all vegetation, roots and trees, the site then boxed out and the sub-grade formed to levels and gradients as required - the site being excavated or filled, as the case may be.

The formation shall be consolidated, ready to receive the required thickness of gravel, or other approved foundation material.

Gravel base

Gravel is to have a total consolidated thickness of not less than 100mm in the case of a residential vehicle crossover, not less than 150mm in the case of industrial crossovers, which are required for service stations, factories, schools and shops, and all places subject to more than residential traffic.

Gravel to be spread, rolled, water-bound and corrected as necessary to shape, grade, etc.

Compaction

The gravel shall be placed in layers and compacted to 98% of the maximum dry density when tested in accordance with AS1289 E2.1-1977.

Surfacing

The surface is to be again reshaped and gravel added where required to give correct shape. The surface is to be well watered and rolled with a vibrating roller, slurried and swept clean of any loose material.

When the foundation is dry:

  • Spray tack coat at a rate of .9 litres per sqm
  •  Apply 20mm consolidated thickness of 5mm hot, non-flux asphalt.

The asphalt to be provided by an approved plant. The aggregate material to be granite.

The material is to be laid at a temperature not less than 160 degrees C (320 degrees F) spread to an even thickness to provide a finished, consolidated thickness of 20mm by vibration. The thickness of the material is to be even and this is to be maintained by approved techniques.

The finishing work shall be undertaken while the material is hot, to produce a fine, dense, smooth surface, free of surface voids.

Edging

The edges of the crossover are to be formed using a flexible 30mm deep steel border pegged to shape (to be removed on completion), to provide a symmetrical and uniform shape and appearance. A gravel shoulder, 500mm wide and 100mm thick, should be provided at the edges of the crossover to finish flush with the top of the asphalt surface.

Concrete kerb laid to finish flush with the final surface of the crossover may also be used as edge restraints if desired, but not essential.

Site tidying

On completion, all surplus materials are to be removed and the site of the works left clean and tidy.

Drainage pipes (if applicable)

All drainage pipes are to be ‘X’ class concrete and shall be spigot and socket rubber ring joint type unless otherwise authorised by the Shire. Minimum pipe size is 375mm wide diameter or as determined by the Shire. Reject pipes or second-hand pipes are not acceptable.

Headwalls (if applicable)

Headwalls are to be constructed from in situ concrete, precast concrete, stone or brick.

Standard crossover details

Standard crossover details diagram (PDF)

More information and contact

For more information contact the Shire's Infrastructure Services Team on 9290 6716 or email shire@mundaring.wa.gov.au