CRC Joint-Cast
The combination of high strength, a large
silica fume content and fibre reinforcement provides CRC
with exceptional bond properties, which are utilized in a
product called CRC Joint-Cast. CRC Joint-Cast is used for
in situ cast joints between pre-cast elements in
conventional concrete. As full anchorage of a reinforcing
bar can usually be achieved with an embedment length of
5-8 bar diameters after only 3 days, CRC Joint-Cast can
provide small and simple joints that have full moment
resistance and considerable ductility.A number of
different types of joints have been tested and for bar
dia-
meters from 8 mm up to 51 mm.
The system was first used to connect
slabs for a new building at Aalborg University. In this
case a column/flat slab system was used where the columns
were placed in a 6x6 m grid. This could have been done
with an in-situ cast slab, but in order to take advantage
of the flexibility and speed of erection of using
elements a system was developed where pre-cast 3x6 m
slabs were joined with CRC Joint-Cast in the middle of a
span and over the columns.
CRC Joint-Cast is used where it can
provide a solution that is better, faster or cheaper and
preferably all of those. Examples could be where
traditional joints are much too complicated or too
expensive, or where the possibility of having a full
strength joint in 3 days can be used in the building
process. Yet another application is in seismic areas, as
the joint is
often the weakest part in precast buildings. With CRC
Joint-Cast the joint has sufficient strength and
ductility to avoid failure in this area.
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