The double wall unit consists of two skins of 65mm thick concrete connected
using a steel lattice girder. The cavity between the skins is then filled
with concrete on site after the panel has been erected. Any tie steel joining
the wall to the foundation or other adjacent double walls or half floor
units is placed in the cavity prior to concreting and the resulting structure
is a single monolithic element when finished.
Typical applications of Double Wall:
Hotel/Apartment/House precast shells
Nursing Homes
Internal dividing walls
Retaining Walls/Bund Walls
Watertight Basements
Tanks (Attenuation and foul collection)
Dock Leveller housings, perimeter retaining walls to industrial units
Lift shafts/stairwells & shear cores
Prison cells
ESB Substation buildings - Compliant with ESB specification number 13320
- MV Substation Buildings (Rev 7)
Advantages:
Considerable saving on main contractor programme against traditional
construction methods
Factory controlled conditions ensure highest accuracy and consistent
manufacturing quality
Greatly reduced labour on site
Excellent acoustic characteristics
Excellent fire resistance, Class 0, BS8110:Part 2
Immediate cosmetic finish, décor can be applied to both faces as soon
as the building is watertight
Easier to comply with health and safety regulations due to the above
savings
Saving on contract preliminary items as complete external scaffolding
can be done away with in some instances or started very late into the
program once the precast shell is nearing completion
Environmentally friendly as there is a minimum of waste on site compared
to traditional building methods
Design:
Wall thicknesses can vary from a minimum of 200mm up to 400mm. All of
the design work required is based on the traditional limit state design
for ordinary reinforced concrete, (BS8110). Panels can be designed for
either load bearing or non-load bearing situations.
Once designed, the building is drawn completely in 3D within the CAD
system of the plant and fully detailed with respect to reinforcement,
cast-in items and openings for windows, doors and services.
Any wall geometry can be accommodated within the limits of our pallets.
Electrical services can also be included in the pre-engineering of the
panels at the design stage. Electrical back boxes and conduits can be
cast in, if required.
Erection:
The procedure for erecting any double wall panel is the same irrespective
of the size or shape. Panels higher than 3,0m have to be turned on site
by 90º.
Customer/Contractor provides a base slab with starter bars, and water
bar if required, ready for first lift of walls.
All grid lines and wall positions are marked directly on the floor slab.
Shims are placed at the wall positions and levelled (typically 25mm)
ready to receive the wall.
The double wall is hooked onto the crane and lifted into position.
When in the correct position 2 No. push pull props are secured to the
face of the panel and the floor slab.
When all panels for a section are in place, plumb and straight the vertical
and horizontal joints are sealed.
Fit the required joint reinforcement.
The cavity of the double wall is filled with a self-compacting concrete
at a rate of 800mm height/hour.
