Concrete vessel having wall apertures lined with tubular inserts

Apertures in the cast concrete walls of a swimming pool are lined with tubular inserts entirely received in the apertures in sealing, conforming engagement with the concrete. The length of each insert in the direction of wall thickness is equal to or shorter than the corresponding length of the receiving aperture. The insert essentially consists of a solid mixture of a particulate, rigid, inorganic material, such as quartz sand, and a smaller amount of a more resilient, synthetic organic resin binder. A fastening flange is provided in the bore of the insert for fastening the insert in a form while the wall is being built by pouring fluid concrete mixture into the form. The flange provides a fastening base for later installed fittings, pumps, etc. During construction of the swimming pool, a form bounding a cavity is erected. The afore-mentioned insert is secured in the form by means of the fastening means, and fluid concrete mixture is poured into the form cavity until the insert is enveloped by the concrete mixture. After curing of the concrete mixture, the form is removed.

This invention relates to vessels having walls of cast or poured concrete, 
and particularly to a vessel having such walls formed with apertures 
therethrough. 
The invention will be described hereinbelow in its specific application to 
a vessel which is a swimming pool, but it is not limited to any specific 
application. 
Practically all large swimming pools have upright and bottom walls of cast 
concrete, the term being used herein to designate the hard product 
obtained by spontaneous curing of a fluid mixture of Portland cement, 
aggregate, and water. Apertures in the swimming pool walls are necessary 
for supplying and withdrawing water from the cavity of the pool and for 
other purposes, and liners of materials other than concrete are often 
arranged in the apertures for connection to various operating elements. 
Tubular liners of metal and plastic were embedded in the concrete walls of 
swimming pools prior to this invention. They have a useful life much 
shorter than that of the concrete walls, and they are not readily repaired 
or replaced without requiring partial destruction and reconstruction of 
the adjacent concrete. 
It is a primary object of this invention to provide a vessel having an 
apertured wall of cast concrete with a tubular liner or insert for the 
aperture which is as durable and resistant to environmental influences as 
the concrete of the wall, but permits operating elements for the swimming 
pool to be connected thereto and to absorb stresses generated by such 
elements more readily than the brittle concrete. 
According to one aspect of this invention a tubular insert received in the 
aperture of the cast concrete wall of the vessel is as long as or shorter 
than the length of the aperture in a direction through the wall. The 
insert is received in the wall aperture in sealing, conforming engagement 
with the concrete of the wall. The insert essentially consists of a solid 
mixture of a particulate, rigid, organic material and of a more resilient, 
synthetic organic resin binder. Fastening means are provided on the insert 
which permit the same to be fastened in the interior of a form while the 
wall is being built by pouring fluid concrete mixture into the form.

Referring now to the drawing in detail, and initially to FIG. 1a, there are 
shown the top edge of a concrete pool and a narrow deck integral with the 
upright pool wall 2 which is still confined between an outer wooden form 
wall 51 and an inner form wall 52 bounding the cavity of the pool and 
connected to the form wall 51 by a multiplicity of threadedly fastened 
spacer rods 53. A tubular insert 1 of generally cylindrical shape about a 
horizontal axis is embedded in the concrete of the wall 2. It is flush 
with the inner, vertical face of the wall 2 so that its bore 13 is sealed 
in one axial direction by the form wall 52. Annular reinforcing ribs 11 
project from the outer cylindrical face of the insert 1 into the concrete 
of the wall 2, and the concrete in turn fills the grooves 12 between the 
ribs 11. 
Near the axial end of the insert 1 remote from the form wall 52, an 
integral radial flange 14 projects into the bore 13. The insert 1 was held 
in position during the pouring of the concrete wall 2 in the form 51, 52 
by a stay bolt 54 anchored in the outer form wall 51. A washer on the stay 
bolt closes the opening bounded by the flange 14. The insert 1 was further 
held in position during the pouring of the wall 2 by a cup-shaped spacer 4 
of cellular polystyrene which prevented the concrete mixture from entering 
a space in the wall 2 axially aligned with the insert 1 whose length is 
smaller than the wall thickness. A notch 55 in the stay bolt 54 permits 
the bolt to be broken with relative ease. 
When the concrete has set, the form walls 51, 52 are removed. It is 
preferred to release the stay bolt 54 before removing the wall 51. If this 
is overlooked, damage to the flange 14 of the insert 1 during removal of 
the wall 51 is prevented by breaking of the bolt 54 at the notch 55. The 
spacer 4 also is removed. 
The tubular insert 1 then provides anchorage and an inlet in the pool wall 
2 for an overflow skimmer 60 as is shown in FIG. 1b. The space around the 
outside of the completed pool is filled with earth 66 on which the deck 63 
rests. Access to the buried overflow vessel 61 of the skimmer 60 is 
provided by an opening 65 in the deck 63, normally closed by a round, 
removable cover 64. A pipe 62 leads from the bottom of the vessel 61 to a 
suction pump, not shown. The inner face of the upright pool wall 2 is 
covered with ceramic tiles 67 which also cover the annular end face of the 
insert 1 flush with the concrete face of the wall. A decorative inlet pipe 
68 of bright metal is received in the insert 1 and has an outer radial 
flange 69 overlapping the tiles 67 near the orifice of the insert 1. 
The insert is pre-fabricated and is installed between the form walls 51, 52 
prior to the pouring of concrete mixture. It consists of inorganic, inert 
particles and a plastic binder cementing the particles to each other. 
Quartz sand provides the preferred particles in all inserts of the 
invention, and polyester resin binders, which are staple articles of 
commerce, are preferred. Depending on the specific nature of the polyester 
resin in the binder, the binder may further include curing and hardening 
agents, such as benzoyl peroxide, secondary binders, such as styrene, and 
coloring matter to give a more pleasing appearance to the parts of the 
insert which may be visible. An insert material which has been found very 
useful for all swimming pool applications illustrated consists basically 
of approximately 80% quartz sand or gravel having a grain size of 0.04 to 
8 mm and 20% polyester resin. 
Under most conditions, the insert 1 is adequately secured in an axial 
direction by the ribs 11 and grooves 12 conformingly interengaged with the 
concrete of the wall 2, but firmer anchorage is obtained by a flat annular 
disc 20 of sheet metal which is embedded in one of the reinforcing ribs 11 
and projects from the rib into the surrounding concrete, as is shown in 
FIG. 1c, the illustrated portion of the swimming pool being otherwise 
identical with what has been described with reference to FIG. 1a. 
The same vertical wall 2 shown in FIGS. 1a, 1b, 1c is provided at an 
intermediate level with another tubular insert 1' of the same material as 
the insert 1, but mounted between the form walls 51, 52 by means of 
several long bolts 54 passing through respective bores in the flange 14' 
of the insert 1', the heads of the bolts abutting against the inner radial 
face of the flange, and the shanks of the bolts passing through the outer 
form wall and carrying nuts. Notches 55 forming frangible, reduced 
portions of the bolts 54 are provided as described above. The insert 1' is 
axially longer than the insert 1, but still shorter than the aperture in 
the wall 2 in which it is set, the remainder of the aperture being sealed 
against ingress of fluid concrete mixture by a spacer ring 4 of cellular 
polystyrene interposed between the insert 1' and the outer form wall. 
After curing of the concrete in the wall 2, the form walls, the bolts 54, 
and the spacer ring 4 are removed, and a circulating pump assembly 70 is 
mounted on the flange 14' by means of bolts as is shown in FIG. 2b. The 
electric motor 71 of the assembly projects outward of the pool wall 2 into 
a concrete-lined compartment 77 in the surrounding earth fill 66. Access 
to the compartment may be had through an opening releasably closed by a 
cover 76. 
The motor drives an axial flow pump 72 arranged behind a baffle 78 in such 
a manner that water flows mainly from the bottom region of the pool toward 
the pump intake, as indicated by arrows 73, while the pump output is 
discharged through a nozzle 74 in a mainly horizontal direction, as 
indicated by arrows 75. 
A further insert 1" is installed between the form walls 51, 52 prior to 
pouring of the pool walls approximately on the same level as the pump 
assembly 80 in a manner evident from FIG. 3a. The element corresponding in 
the insert 1" to the afore-described flanges 14, 14' is a partition 15 
formed with a relatively small central, axial aperture 82. The insert 1" 
is initially clamped to the outer form wall 51 by means of a bolt 54 
having a frangible portion at a notch 55. The head of the bolt abuts 
against the outer radial face of the partition 15, and its shank passes 
through the form wall 51. A spacer ring 4 of cellular plastic is clamped 
between the form wall 51 and the outer, annular end face of the insert 1". 
As is seen in FIG. 3b, a floodlight 80 is mounted in the bore 13 of the 
insert 1" after removal of the form walls 51, 52 and associated elements 
in the manner described above. The power supply cable 81 for the 
floodlight passes through a sealing plug 83 in the aperture 82, but the 
pre-fabricated insert 1" is also provided with a radial passage 84 
communicating with the bore 13 for accomodating a power cable and plugged 
in the illustrated embodiment. The floodlight 80 is held in position in 
the wall 2 by a flat mounting ring 85 which may also carry a pane of 
glass. 
The modified insert 1" shown in FIG. 3c is axially as long as the spacing 
of the form walls 51, 52, and thus as long as the thickness of the 
finished concrete wall 2. It does not need a spacer 4 to be held in 
position between the form walls during the pouring of concrete for the 
pool. A flat, annular disc 20 is anchored in one of the external 
reinforcing ribs 11 of the modified insert 1". It is formed with a row of 
circumferentially distributed openings 21 therethrough which are filled 
with the material of the insert 1" during the molding of the latter at 
elevated temperature and pressure from the mixture of quartz sand and 
polyester resin binder. After curing of the concrete in the pool wall 2, 
the modified insert 1" serves as a mounting base and receptacle for a 
floodlight in the manner shown in FIG. 3b. 
Water is fed to the pool partly illustrated in the drawing figures 
described above by an inlet arrangement respectively shown in FIGS. 4a and 
4b in an intermediate stage of construction and after completion. 
The pre-fabricated sheet 1"' which is the base of the inlet arrangement is 
axially substantially shorter than the spacing of the form walls 51, 52. 
It has a flange 14" spacedly adjacent the inner form wall 52 and is held 
in position prior to and during pouring of the pool wall 2 by a bolt 54 
whose head holds a large washer against the inner, radial face of the 
flange 14", and whose shank passes through the outer form wall 51, a notch 
55 making a portion of the bolt 54 readily frangible. Ribs 11 and grooves 
12 conformingly interengage the poured concrete of the wall 2. 
The centrally apertured plug or ring 4 of cellular polystyrene which is 
axially interposed between the insert 1"' and the outer form wall 51 has a 
V-shaped, circumferential groove 41 which permits the axial length of the 
plug or ring 4 to be reduced to a precise value with the simplest of 
tools. The plug initially had several, axially spaced grooves 41 and was 
reduced to the illustrated axial length by splitting the initial blank of 
foamed plastic along one of the grooves. 
After removal of the forms 51, 52, a pipe coupling 91 was coaxially bolted 
to the flange 14" as is shown in FIG. 4b. The discharge end of a plastic 
supply pipe 92 is adhesively secured in the coupling 91 in a position in 
which it abuts against an internal shoulder of the coupling. Another pipe 
94 carrying an ornamental, radial flange 93 is inserted into the coupling 
from inside the pool, and the flange is fastened to the wall 2 by bolts 95 
which pass through openings in the facing tiles 67. A nozzle 96 rotatably 
mounted in the orifice of the pipe 94 permits water supplied through the 
pipe 92 to be directed inward of the pool in a desired direction. 
The bottom drain of the pool is shown in FIG. 5 in an intermediate stage of 
construction. Two inserts 1.sup.iv, 1.sup.v of polyester-bonded quartz 
sand are installed prior to pouring in the portions of the pool form which 
define the shapes of the bottom wall 3 and of one of the upright walls. 
They engage each other in a bell-and-pivot joint 100. Rubber sleeves 104 
line the axially adjacent, joined portions of the two inserts. Lips of the 
sleeves 104 overlap the two annular, radial end faces 17 of the inserts 
1.sup.iv, 1.sup.v which bound a narrow annular gap between the inserts, 
and a polyvinyl chloride tube 105 frictionally received in the sleeves 104 
bridges and seals the gap. 
The insert 1.sup.iv is an elbow fitting having a wide, upwardly directed 
opening remote from the horizontally straight, tubular insert 1.sup.v. An 
integral boss projecting vertically from the wall of the insert 1.sup.iv 
into the bore of the insert and toward its wide opening is aligned with 
the center of the opening and provided with a vertical bore 16 in which a 
drain valve, conventional in itself, will be installed in the completed 
pool portion, not specifically illustrated, but obvious from the preceding 
description. 
While the invention has been described with particular reference to a 
swimming pool having cast concrete walls, it is applicable in an obvious 
manner to other concrete-walled vessels having apertured walls and 
operating elements of different materials associated with the apertures. 
Storage and processing tanks for liquids other than water, silos for 
grain, and storage bins for other particulate solids are merely 
representative of such other applications. 
Tubular inserts pre-fabricated from a mixture of rigid, inorganic particles 
and a resilient binder of synthetic resin composition combine properties 
valuable in each of these and many other applications. The exact nature of 
the particulate component and of the resilient binder will readily be 
selected to suit particular requirements which may be more demanding than 
those in swimming pool service. The fact that the tubular inserts of the 
invention are entirely received within the apertures of the concrete wall 
widens the choice of suitable materials which are protected by the 
concrete wall against mechanical damage and many atmospheric agents 
including solar radiation which accelerates aging of many plastics. 
In most applications, it is necessary that the material of the insert be 
wetted by and integrally bonded to the Portland cement mixture normally 
constituting the matrix of a concrete wall. The afore-described mixture of 
quartz sand and an organic resin binder, not necessarily polyester binder, 
fully meets this requirement. The annular metal disc 20 shown in FIGS. 1c, 
3c, and 5 not only strengthens the mechanical bond between the insert and 
the concrete wall, it also impedes leakage along the interface of the 
insert and the wall if a leakage path should have been created by faulty 
pouring technique. The disc may consist of the conventional low carbon 
steel commonly employed for reinforcing concrete which bonds firmly both 
to Portland concrete mixture and to the mixture of sand and polyester 
resin which preferably constitutes the tubular insert. The thickness of 
the disc may be as small as 0.5 mm or as great as 3 mm, and it may project 
beyond the outer circumference of the insert by ten to one hundred times 
its thickness. It is most effective if anchored in a portion of the insert 
strengthened by a reinforcing rib 11, and if provided with openings 21 
filled with an integral portion of the material constituting the insert. 
It should be understood, of course, that the foregoing disclosure relates 
only to preferred embodiments of the invention, and that it is intended to 
cover all changes and modifications of the examples of the invention 
herein chosen for the purpose of the disclosure which do not constitute 
departures from the spirit and scope of the invention set forth in the 
appended claims.