TRADITIONAL APPROACH
The standard method of building ‘tiered’ concrete slabs has demanded
that one establish a well compacted, ‘sloped’ base. Several factors work
against the successful preparation and maintenance of the inclined
grade: stable fill materials, unsuitable weather conditions,
installation and bracing of the forming system, installation of
structural reinforcing, and accessibility to various construction
workers applying their trade.
ALTERNATE APPROACH
Another method requires forming and placing concrete one ‘tier’ at a
time. After placing the lower row, subsequent rows of concrete will bear
upon six inches of the previous row(s). After stripping the edge forms,
fill is brought in and compacted to the top level of the adjoining
concrete. This redundant and labor intensive technique yields an
assembly of disconnected slabs that risk shifting and settling.
INNOVATION
An early advancement in this industry was the development of
pre-assembled gang forms; fabricated to the needs of a specific project.
While these heavy (crane handled) forms can significantly reduce labor
costs, the concept only works when there is enough reuse to justify the
cost to build the forms and transport them.
IMPROVEMENTS
For nearly two decades, contractors have used EPS Geofoam as a
lightweight replacement for compacted fill. This proven material
provides a substantial base that is ‘capped’ with concrete to produce
‘tiered’ slabs. This method has found a welcome acceptance by those in
the business of building movie theaters and cinemas.
SYSTEM APPROACH
2007 ushered in the newest and most versatile method for constructing
‘tiered‘ concrete slabs. RISER SOLUTIONS® can easily adapt to the needs
of smaller or unusual projects; yet it not uncommon to see it used on
larger, and more demanding jobs. In particular, ‘tiered’ concrete slabs,
designed with a radius configuration of the riser faces, can be built
with the same confidence as jobs with straight riser faces. Previous
construction methods have provided either 1) structural concrete over
marginal fill or 2) non-structural concrete over engineered fill. RISER
SOLUTIONS®
is a hybrid system, offering rapid and accurate installations of
structural concrete over EPS (expanded polystyrene), a light density,
engineered fill. Whether used for ‘stepped’ concrete slabs, large
stairways, or frost protected entry stoops; the design and installation
of ‘tiered’ structural concrete, slabs is reaching new potentials. |
