A gabion is a cage, cylinder, or box filled with soil, sand or rocks that can be used in drainage channel construction, road building, shore protection works or other civil engineering works, undertaken by councils.
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If rocks are used, suitable sizes are 100 mm to 200 mm. The Australian Standard AS2758.4 - 2000 Aggregate for gabion baskets and wire mattresses, specifies aggregate requirements suitable for use in gabion structures.
A Mattress is a commonly used form of gabion with relatively small height relative to the lateral dimensions; commonly very wide. They are used to protect surfaces from wave erosion and similar attack, rather than building or supporting high structures.