Bottom Structure

The type of pit lining depends on site conditions to be assessed by the engineer on site.
Ferrocement lining to be constructed by first applying a single 20mm thick layer of mortar. Fixing wiremesh with 50mm spacing onto this layer and then applying a 20mm layer of mortar over this layer.
Brick lining consists of M140 concrete blocks. Vertical joint openings in every third block and galvanised brickforce every second course.
Note that no openings are permitted within the first 500m of lining below ground level.
All concrete precast items to be 35mpa.
All other concrete applications to be 25mpa.
Mortar shall be 5 parts sand to 1 part cement.
Mortar to be dry mixed until a uniform colour and whole turned until thoroughly and evenly mixed.
Mortar shall be freshly mixed and mortar which has begun to set shall not be used.
Mortar shall be mixed by hand, special care to be taken to remove any old mortar which has already set before commencing to mix a fresh batch.
All steelwork shall be galvanised.
Soil analysis required to determine correct pit formation. Incorrect design may lead to collapsing structures.