Mattresses are designed to be laid flat on a prepared slope, joined together, and then filled with
concrete (Figure B-13). From a large mass of pillow-like concrete sections with regularly spaced filter
meshes for the passage of water.
Bags and mats should be placed only on a stable slope. When a stacked bag revetment can be
placed at a steeper slope that mattress, it should not exceed 1 vertical on 1.5 horizontal. stacked bag
revetment should be at least two bags thick. For permanence, the outside layer should be concrete-filled
but the layer may be sand-filled.
Bags that have been used include:
Burlap Bags
These are recommended only when filled with concrete because of their rapid deterioration and the
ease with which they can torn.
Sand Pillows
Sand Pillows are ultraviolet-resistant bags made from woven acrylic fabric. They weigh approximately
100 pounds when filled.
Dura Bags
Dura Bags are large (4 x 12 x 1.7 feet) and must be filled i place with a pumped sand slurry or
concrete. Their large size makes them more resistant to movement under wave attack. Fabricated of
ultraviolet-resistant material, they can be used in e posed installations.
Fabriform Nylon Mat
The mat is designed to be filled with a highly fluid grout mixture. The exterior cloth envelope
serves primarily as a for until the grout hardens. Fabriform comes in several fabric styles. Including
some with filter points (weep holes) for slope drainage Fabriform mats are patented and should be
installed according the manufacturer's instructions.
MISCELLANEOUS REVETMENTS
Gabions
Wave Height Range: Above five feet.
Runup Characteristics: Rough.
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