Hybrid Concrete Construction
Hybrid concrete construction (HCC) is a method
of construction which integrates precast concrete and cast in-situ
concrete to make best advantage of their different inherent
qualities. The accuracy, speed and high-quality finish of precast
components can be combined with the economy and flexibility of cast
in-situ concrete.
Hybrid concrete construction produces simple,
buildable and competitive structures. The client is given better
value and the contractor benefits from increased off-site component
manufacture, safe and faster construction and consistent
performance.
Benefits of using HCC
Cost
Although the structural frame of a building
represents only 10 per cent of the total construction cost, the
choice of material for the frame has dramatic consequences for
subsequent processes. HCC is able to offer greater speed, quality
and overall economy on a project.
The use of concrete has additional benefits in
assessing whole-life costs, a factor important to owner-occupiers
and PFI operators. For example, the thermal mass of concrete can
moderate energy demands in cooling and heating buildings.
Buildability
As precast and cast in-situ concrete are used
where most appropriate, construction becomes relatively simple and
logical. The use of HCC encourages design and construction
decisions to be resolved at design stage.
The use of HCC also means that a percentage of
the frame is manufactured by a skilled workforce in a weatherproof
factory, resulting in faster construction and better quality.
Safety
A high proportion of the work for a hybrid
concrete construction project is carried out in the precast
factory. On site, the use of HCC helps ensure that each safety plan
is drafted on the individual project’s merits. HCC can reduce the
potential for accidents by providing successive work platforms on a
generally less cluttered site.
Sustainability
HCC offers the opportunity to exploit the
inherent thermal mass of concrete by
exposing the soffit of precast concrete floor slabs. This fabric
energy storage (FES) of the structure can help to control
temperatures in the context of a naturally ventilated low-energy
building. The finish and shape of exposed concrete units can also
be used to help with the even distribution of lighting and to
reduce noise levels.
Concrete structures have the equivalent less
embodied energy and CO2 emissions than structures built using other
materials. For all buildings the operational energy consumption is
far more significant than that during construction, but concrete
buildings utilising thermal mass can reduce this impact on the
environment by minimising the need for air-conditioning.