Note: Descriptions are shown in the official language in which they were submitted.
THIS INVENTION relates to improvements to
liquid retaining structures and in particular to
improved swimming pool constructions.
Ingrained liquid retaining structures, or
example swimming pools, are formed by many different
methods. In a common form of construction, an area of
ground is excavated and a reinforcing structure normally
formed by interconnecting a plurality of reinforcing
rods is placed within the excavation. Furthermore, a
reinforcing structure is formed within boxing form work
around the upper periphery of the pool to define the pool
coping and provide the required structural strength.
Subsequently, concrete is applied preferably by spraying
to cover the reinforcing structure to form the pool
walls, floor and coping. In this known arrangement, however,
a considerable period of time is required to bend and
interconnect the reinforcing rods to form the reinforcing
structure and accordingly, the construction method can be
relatively expensive. Furthermore, the time delay between
forming the reinforcing and applying the concrete can cause
difficulties if weather conditions subsequently prevent
the application of the concrete.
The present invention aims to overcome or
alleviate at least some of the above disadvantages by
providing an improved method of forming a liquid retaining
structure which at least substantially reduces and in some
circumstances completely eliminates the use of a separate
reinforcing structure and which, therefore, enables the
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rapid and economical constructiorl of a liquid retaining
structure such as a pool. Other objects and advantage
of the invention will become apparent herein.
With the above and other objects in view, tnia
invention resides broadly in a method of forming a liquid
retaining structure, including the steps of applying to a
side wall of a cavity formed in the ground a first mix of
concrete to define a first wall layer; applying to said
first wall layer a second concrete mix to form a second wall
layer, said second concrete mix containing steel fires and
said second wall layer being extruded upwardly above said
first wall layer to define about at least portion of the
upper periphery of said liquid retaining structure a
reinforced coping beam.
In order that the invention may be more readily
understood and put into practical effect, reference will now
be made to the accompanying drawings wherein:-
Fig. 1 is a cut-away view showing the wall and
floor construction of one form of liquid retaining
structure according to toe present invention; and
Figs. 2 and 3 illustrate in sectional view
alternative embodiments of a wall and adjacent portion
of the floor of liquid retaining structures in
accordance with the invention.
In a construction of a pool in accordance
with the present invention and a shown in Fig. l, a
suitable site for the pool is initially excavated to form
a cavity 10 to a desired pyrometrically shape having at least
one upstanding side wall 11 and a floor 12 which may be
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53
of any desired contour. Normally at least the exit
side wall 11 is relatively rough and undulating due tug
the nature of the excavation equipment employed.
After formation of the cavity 10, a concrete
mix is applied preferably by spraying directly onto the
excavated side wall 11 to form a first layer of concrete
13. This first layer of concrete fills in undulations in
the excavated wall and is applied so as to form a substant-
tally even surface 14 to accept a second layer of concrete
mix. The concrete mix in the first layer comprises a
Port land cement, aggregate, sand and water mix, or any
other relatively inexpensive cement mix and will hereinafter
be referred to as lea first concrete mix".
Tory the first layer 14 is formed and
allowed to at least substantially set, a concrete mix
reinforced with steel fires (commonly known as FIBRESTEEL~
is applied to the first layer surface 14 to form a second
inner layer 15 which defines the inner wall of the pool.
The steel fire reinforced layer at the same time is also
extended upwardly above the first layer 13 to form a coping
beam 16 with or without the assistance of conventional
stuttering or boxing arrangements. The so-formed coping
berm 16 extends around the upper perimeter of the pool
and being formed of steel fire reinforced concrete, defines
I a structural berm member which is Effective to resist
occupy and/or herding stresses which may be venerated in the
pool. This, therefore, permits the elimination of
conventional reinforcing rods or the like which are normally
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used in formation of a coping beam whilst maintaining
the necessary structural strength in the pool. Furthermore,
the inner steel fire reinforced layer 15 also acts as a
structural element to resist stresses.
The above construction therefore is relatively
inexpensive as use of reinforcing rods may be eliminate
by the use of the outer relatively thick first layer
of relatively inexpensive concrete and an inner relatively
thin layer of more expensive steel fire reinforced
concrete.
A pool constructed in accordance with the
above method is particularly suitable for use with a
flexible vinyl liner 17 and for this purpose the excavated
loon of the pool may be covered with a sand bed 18 and
fixing strip 19 attached to the inner steel fire
reinforcing concrete wall adjacent the upper edge of the
coping 16 so that the vinyl liner 17 is supported in use.
Alternatively, the sand bed 18 may be replaced by steel
mesh reinforced concrete, steel fire reinforced concrete
or other concrete reinforced with ibres such as polypropylene
fires. Furthermore, conventional brick or exposed aggregate
or other finish can be applied to the coping to form the
normal pool walk around area 20.
In a further embodiment of the invention
shown in Fig. 2, the first concrete mix layer 13 applied to
the side walls may also be extended to form a floor layer
22 end for this purpose, the floor layer 22 is preferably
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so
applied over a sand bed 23 initially laid on the flyer of the excavated cavity lug. floor reinforcing
assembly 24 preferably comprising a plurality of inter-
connected reinforcing rods is arranged over the floor
layer 22 and extended upwardly partly along the surface
14 of the wall layer 13 as illustra Ed A steel fire
reinforced concrete mix is then sprayed on to the surface
14 of the outer wall layer 13 to form the inner wall layer
15 which as in the above embodiment is extended upwardly
above the layer 13 to define the reinforced coping beau
16. The floor layer 22 is then covered with a further
layer 25 of concrete which covers the reinforcing assembly
24. In this arrangement, or the arrangement of Fig 1, the
walls and floor of the pool may be finished with colored
or plain concrete render, synthetic plastic render,
sprayed pebble or an exposed aggregate finish, or alter-
natively, a vinyl liner may be-fit-ted.
In yet an alternative method of construction
shown in Fig. I the outer wall layer 13 it initially
formed and subsequently a floor reinforcing assembly 26
preferably comprising a plurality of interconnected rein-
forcing rods, is arranged at the floor 12 of the excavation
and extended partly along the surface 14 of the wall layer
13 as illustrated. A steel fire reinforced concrete mix
is then sprayed onto the outer wall layer 13 to form the
inner wall layer I so khaki the upwardly extending portions
of the reinforcing are covered. The steel fire reinforced
layer 15 is also extended upwardly to define the coping 16
' .,
So
in the manner described above. The floor of the exca~ ion
may then be sprayed with concrete mix preferably of the
type used for the first layer 13 to cover the floor
reinforcing and form a reinforced concrete pool floor 27.
The walls and floor of the pool may then be finished in
any of the above described manners.
Preferably the steel fire reinforced concrete
side walls on the above embodiments are constructed to
be approximately 25 mm. to 70 mm. in thickness. Thus,
the method of construction of the present invention enables
pools or other liquid retaining structures to be manufactured
quickly and efficiently and with a minimum of cost, whilst
the elimination of or reduction in the use of reinforcing
material enables the construction of a pool in a relatively
short time.
The method ox the present invention is
particularly suitable to the construction of rectangular
pools. However, of course the method may be applied to
any shape ox pool or other liquid retaining structure.
Whilst the above has been given by way of
illustrative embodiment of the present invention t all
such modifications and variations a would be apparent
to persons skilled in the art are deemed to Hall within
the broad scope and gambit ox the invention as herein
defined by the appended claims.
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