Kingscote Streets Upgrades - Kangaroo Island Council

No pumping will be permitted during the placing of concrete or for a period of at least 24 hours after,
unless it be done from a suitable sump separated from the concrete work by a watertight wall or by
other effective means.
If water entering any excavation is considered by the Superintendent to be of sufficient quantity to
damage fresh concrete, the Contractor shall at his own expense enlarge the excavation as directed
by the Superintendent, erect watertight forms to support the concrete and carry out pumping from
outside the forms for a period of twenty-four hours after placing the concrete.
4.3.17 Removal of Soil From Drainage lines
Any soil or other material entering the pipes during the construction of the drain shall be
progressively removed as pipe laying proceeds so that the drain provides an unobstructed waterway
of the specified diameter upon completion.
4.3.18 Sealing Off
The ends of reinforced concrete pipe drains shall be sealed off in the locations shown on the
drawings, using a precast concrete slab or a mortar jointed concrete block wall constructed prior to
backfilling. The method of sealing shall be such as to avoid any dislodgment during backfilling
operations and shall be to the prior approval of the Superintendent.
4.3.19 Scour Protection Apron
The scour protection aprons shall be constructed in the locations and to the details shown on the
drawings.
The finished surface of the scour protection aprons shall conform generally to the shape and levels
of the adjacent natural surface. The area in the vicinity shall be trimmed and formed up to allow the
construction to be carried out to this requirement.
The scour protection aprons shall be formed using hard and durable quartzite or dolomite stones,
individually placed so as to provide some mechanical interlock and grouted in using a 1:3 cement
and sand mortar. The grouting shall be finished to a surface at or slightly below the general level of
the stones. Stones shall be thoroughly wet before the grouting is applied.
The stones shall be of reasonably uniform size with a face area in the order of 0.1 square metres.
On completion of the construction of the scour protection aprons, all debris shall be removed and the
surrounding ground disturbed by the construction shall be reinstated by filling as necessary,
compacting and grading off to conform to the adjacent ground conditions.
4.3.20 Scour Protection
Stone scour-protection shall be constructed at the outlet of the drain where detailed on the drawings.
The construction shall be to the details shown on the drawings.
The stone-pitched scour protection shall be constructed downstream from the reinforced concrete
outlet to the details shown on the drawings. The site shall be excavated to suit the specified
construction and the subgrade so formed shall be compacted using a vibrating tamping unit or
similar compaction equipment to give a density of at least 90% of the modified maximum density.
A layer of 20 mm sized quartzite or dolomite gravel of 150 mm nominal thickness shall be placed on
the prepared subgrade and compacted using a vibrating tamping unit or similar to give a uniformly
compacted surface for the placement of the rip-rap.
The rip-rap shall consist of hard and durable quartzite or dolomite material and shall be of a
reasonably uniform size with approximate dimensions of 250 mm in a cubic shape. The individual
stones shall be carefully placed on the prepared gravel bedding to give a basin of the shape and
sizes shown on the drawings. The stones shall be placed so as to provide some mechanical
interlock and shall be grouted in using a 1:3 cement and sand mortar. The grouting shall be finished
to a rough surface at or slightly below the general level of the rip-rap.
Ref No. 20120236SA1 Kingscote Streets Upgrades Technical Specification 18