Structural Floor Panels Design Guide - Hebel Supercrete AAC ...

3.2 Lifting
3.2.1 Crane and Lifting Procedure.
The bundles of panels are un-strapped and the first panel
rolled off the supporting timber strapping blocks and laid
on its flat, using car tyres, or similar, as a cushioning support.
Position the tyres to allow the lifting cradle to get access to
the panel at mid span. Ensure the panel is sitting with the
top surface up. This is the face with the ring anchor grooves
on the top edge.
Using lifting strops (rated for the load).
A variety of lifting devices can be used. Even a 5.6 metre
long 250mm thick panel weighs less than 600kg and more
typical 4 metre, 150mm thick panels weigh in at around
250kg each. This means that panels have been installed
using small truck-mounted cranes, fork trucks and tractors,
gantry cranes, even stropped off a digger bucket arm. The
key consideration is not usually the weight of the panel to
be lifted, but rather the reach of the crane/lifting machinery
being used.
Lifting with a forklift
Driver/operator visibility may also play a part in crane
choices, although on lifts to multi storey buildings, the
operator is often unable to see the drop zone and relies on
good radio communication with the install crew to position
the panel.
The Supercrete Panel cradle is a clamp that fits to the
lifting chain/cable of the crane. It is swung into position at
the mid span of the panels that have been laid flat on the
tyre supports. A lever opens the jaws of the cradle and
once the weight of panel is applied as the lift commences,
the jaws clamp shut. Safety chains wrap around the panel
to ensure it does not slip out. These chains are removed as
the panel is placed.
A lifting cradle in use. Safety chain detached
for placement.
3.2.2 Panel Placement Times
Panel placement times vary depending upon the following
factors;
a) How close the bundles of panels can be delivered to
the intended position on the building
b) The speed of the horizontal travel of the crane boom
c) Whether the panels need to be cut to size on site.
d) The rhythm, or efficiency of the team of personnel
e) The adequacy of the support system (walls and beams
in the right place and at the correct levels)
Times ranging from 5 to 6 minutes per panel for simplistic
easily placed panels up to 15 minutes per panel for
complicated layouts (including panel cutting, or difficult site
access, slow cranes, etc) have been reported. This gives
between 4 and 10 panels per hour. Depending upon the
surface area of the panels, square metre rates will vary
accordingly.
Lifting cradles are fitted to truck mounted
cranes.
SFP 2012 44 Copyright © Supercrete Limited 2008