Water, Sewage & Effluent July August 2018 | Page 19

Seals bottom of cells against base The rigging is used in conjunction with Y10 rebar pegs to firmly draw the cell walls into intimate contact with the underlying material. This prevents the grout that is cascading down the slope over the tops of the cell walls from flowing underneath the cell mat instead, wasting large volumes of grout and eliminating the flexibility of the cast articulated paving. More rigging strings are required on slopes than on the dam floor and Meintjies threaded extra rigging lines on site, using the pre-drilled holes supplied for this option. The weight of the wet grout held on the slope is considerable and Meintjies found that even with the extra rigging strings, he had to adopt the technique of casting the walls in strips — cast one, miss one — and return to fill the gaps when the first series of panels had set. The weight of the wet grout on a slippery slope is a feature that makes armouring of a conventional plastic liner a much slower and more difficult process, especially as care must be taken not to damage the liner. environment Hyson Cells has always used integral rigging because it is needed to assist in imparting rigidity to the thin-walled cells for filling. When pouring the cement grout on slopes, the use of the rigging is critical. Importance of the rigging Working in panels owing to the weight of the wet grout. Water Sewage & Effluent July/August 2018 17