Kingscote Streets Upgrades - Kangaroo Island Council

The surface of the base slab shall be screeded off to the levels and cross-sections shown on the
drawings and trowelled to a smooth steel float finish.
4.3.13 Box Culvert Installation - Crown Units
The precast concrete box culvert crown units shall be laid on the previously placed base.
Where precast base slabs are specified, the crown sections shall be accurately positioned so that
the joints between the crown and base sections coincide.
The crown sections shall be seated evenly on the base, by bedding in 1:3 cement and sand mortar if
necessary.
4.3.14 Box Culvert Jointing
Culvert units shall be jointed externally by applying joint sealing tape (Densopol 60HT or similar)
fitted in accordance with the manufacturers recommendations.
The internal rebate of each joint shall be carefully packed with 1:2 cement and sand grout and tooled
to give a smooth finish.
4.3.15 Backfilling and Surface Reinstatement
After the initial backfilling with surround material has been completed, the remainder of the trench
shall be backfilled and the surface reinstated in accordance with the requirements of the Site
Preparation and Earthworks section of this specification.
4.3.16 Drainage Structures
Drainage structures include, headwalls, wing-walls, junction boxes, side entry pits, drop structures
and energy dissipaters.
All drainage structures shall be constructed to the lines, levels and dimensions as shown on the
drawings. The Contractor shall make provision during pipe laying for all such drainage structures by
setting pipes to levels and locations shown on the drawings.
All maintenance holes, junction boxes, inspection pits, side entry pits or other drainage structures
shall be fitted with a cover and frames as approved by the Superintendent. All such covers and
frames shall be supplied by the Contractor and shall include the provision of key and concrete infill
where applicable. They shall be installed in accordance with the manufacturer's instructions.
Concrete work shall comply with the relevant requirements of the AS 3000 Concrete Structures, the
design drawings and any Standard Council details. Reinforcement for drainage structures shall be
manufactured and supplied in AS 4671 – “Steel Reinforcing Materials” class N and installed in
accordance with AS 3600 – “Concrete Structures”.
All steel components shall be hot-dip galvanised prior to installation. Covers and frames for drainage
structures will be as per the drawings and in accordance with AS 3996 – “Metal Access Covers,
Road Grates and Frames" and AS 4198 – “Precast Concrete Access Chambers for Sewerage
Applications” as appropriate.
Particular care is to be taken with streamlining of all internal surfaces of sumps, junction boxes and
pipe joints, as required by and shown on the drawings. Joints between drainage lines and precast
drainage structures shall be strengthened with a concrete “bandage” of a minimum of 100 mm thick,
encircling the pipeline at the joint .The inside joint between drainage lines and pipelines shall be
rendered flush with the inside wall of the structure with mortar or equivalent.
Top of the cover or grade including frame shall be flush with the paving surface or 25 mm above the
finished surface of landscaped areas as appropriate.
4.3.16.1 Ground Water Pumping
No concrete shall be placed in water. Should pumping be necessary from the interior of any
excavation, it shall be done in such a manner as to preclude the possibility of the movement of water
through any fresh concrete.
Ref No. 20120236SA1 Kingscote Streets Upgrades Technical Specification 17