Bulk filling generally uses a cement/pulverised fuel ash (PFA) mix to suit site conditions with compressive strengths in the order of 1.0 N/mm2. The mixes may include sand and bentonite etc as required. Gravel is introduced to fill major voids and/or to form containment barriers.
Bulk infill grouting is normally carried out from primary grout injection holes on a square grid with secondary and tertiary holes as required.
Keller has extensive knowledge of grout injection and grout mixes, a variety of rig types to accommodate access constraints and can offer alternative grout mixes to mitigate dust.