Supply of A1a crushed stone backfill Sieved backfill Tile backfill Red sand Plastering sand Shaqra'a permeable sand Bat'ha sand Building sand Concrete mix sand Silica sand Splatter sand 3/4 gravel 3/8 gravel Inch stone gravel Zero gravel Asphalt shell Base course backfill Sub-base backfill Dug, compacted, and waste transported Backfilling and compacting necks and beams in layers according to the laboratory