right contractor, to meet the project’s specific
requirements. This resulted in the appointment
of a specialist waterproofing consultancy. With a
new contractor and a new specification in hand,
the waterproofing works commenced again in all
earnest, following the re-installation of the acrylics.
The new product installation did not go without
its own inherent problems, as the application
method had to be changed from spray-on as
advised by the product supplier (but which proved
impossible), to roll on, having a further knock-on
effect on both cost and time.
Project Close
In view of the above, the tank completion was
delayed by almost 18 months and was successfully
opened to the public in June 2016.
ARCHITECTURE & STRUCTURE
The new I&J Ocean Exhibit is a 20x12m reinforced
concrete rectangular tank with chamfered corners.
The concrete walls provide support to the adjoining
first floor and roof slabs. The floor of the tank is
a reinforced mass concrete raft founded on the
Two Oceans Aquarium
in-situ rock. The floor varies from 550mm to
400mm thick and was cast as a continuous pour
with no construction joints.
The main tank concrete wall panels were poured
in single continuous 8m high lifts to avoid horizontal
construction joints. To make this possible, pull-out
bars were used for the adjoining slabs, together
with mechanical couplers for the adjoining beams.
PVC waterstops anchored into the floor slab were
used between adjacent wall panels.
Formwork for the tank walls was kept in place
for a minimum of 7 days as part of a stringent curing
regime. Concrete with a corex-slag replacement
of 50% was specified for the tank structure
to increase marine-classification durability.
Additionally, the concrete was waterproofed with
a specialist elastomeric polyurea lining to meet a
completely water-tight specification.
Specialist rebates were provided to the acrylic
windows and tunnel roof to accommodate the
stringent tolerances required by the acrylic
installer. In most cases, specialist form rebates
were constructed off site to mimic the acrylics,
and installed within the formwork.
BELOW:
NORTH ELEVATION
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