Note: Descriptions are shown in the official language in which they were submitted.
CA 02488149 2004-11-22
Docket No. 027262-195
POLYMER CONCRETE PIPE
CROSS-REFERENCE TO RELATEb APPLICATION
[0001] This application claims the benefit of U.S. provisional application No.
601525,506, file November 26, 2003, the entire specification of which is
incorporated herein by
reference.
TECHNICAL F'I1;LA
[0002] The present application relates generally to polymer concrete pipe, and
more
particularly to polymer concrete pipe having a cost-saving configuration.
EACKGROUND
[0003] Polymer concretes have been known and used for various purposes for
sonic time.
Examples of polymer concrete compositions include those described in U.S.
Patent Nos.
6,048,593; 6,034,155; 4,737,538 and 4,371,639.
[0004] One of the primary obstacles to widespread use ofpolymer concrete
compositions is the cost associated with such compositions. For ~xaraple,
standard Portland
cement concretes tend to cost about one fifth (!/5) that of a typical polymer
concrete mix. To
daft, use of polymer concrete compositions has been mostly limited to
specialized applications
where the price of the structure formod of the polymer concrete composition
can be justified and
obtained in the marketplace. In most applications for concrete pipe, the
additional cost cannot be
justified in the marketplace. However, in certain concrete pipe applications
it would be desirable
to use pipe having the advantageous properties of polymer concrete. Those
advantageous
properties include added strength and exceptional chemical and corrosion
resistance.
[0005) Accordingly, it would be desirable to provide a polymer concrete pipe
configuration that provides the advantages of polymer canerete while at the
same time rtducing
the impact of the high price ofpolymer concrete.
SUMMARY
[0006] Polymer concrete pipe configurations are formed to reduce the requir4d
amount of
polymer concrete.
-1_
CA 02488149 2004-11-22
Docket No. 027262-195
[0007) The details of one or more embodiments are set forth in the
accompanying
drawings and the description below. Other features, objocts, and advantages
will be apparent
from tho description and drawings, and from the claims.
BRIEF DESCR.E'1'ION OF THE DRAW>rTGS
[0008] Fig. 1 is a cmss-section along a longitudinal axis of one embodiment of
a polymer
concrete pipe incorporating a sexiss of spaced apart ribs;
[0009] Fig. 2 is a partial cross-section along a longitudinal axis of another
embodiment of
a polymer concrete pipe incorporating a series of spaced apart ribs;
[0010] Figs. 3 and 3A illustrate another embodiment of a polymer pipe using a
reinforcing void form;
(0011] Figs. 4A-4C are cross-section views of various resinforcing void form
embodiments; and
[0012] Fig. 5 is a partial cross-suction along a longitudinal axis of another
embodiment of
a polymer concrete pipe.
RETAILED DESCRIPTION
(0013] Referring to Fig. 1, an exemplary polymer concrete pipe 10 has inner
diameter D
and includes a unitary tubular member 12 having a primary wall portion ! 4 and
a plurality of
reinforcing ribs 16 extending radially outwardly floor the wall portion's
periphery, positioned at
selected locations along a length of the tubular member. The reinforcing ribs
16 are sized and
positioned to reinforce the primary wall portion 14 and can be formed of the
same polymer
concrete forming the primary wall portion 14 of the tubular member 12. The
ribs may be unitary
with the primary wall where the primary wall and the ribs are formed
simultaneously with each
other. In the example of Fig. 1, the n'bs are generally annular in
configuration.
[0014] In the illustrated embodiment of Fig. 1, reinforcing members 18 located
in the
primary wall have a solid, circular cross-suction and arc arranged in an
overlapping cross-hatch
style funning a layer or region 21 located within the primary wall portion,
while reinforcing
members 18' arc shaped as individual bands or rings located in the ribs 16.
Suitable materials
for forming the reinforcing members include metal, such as steel, and/or
fiberglass rods or
strands. As will be described below, other configurations for reinfom3ng
members arc
-2-
CA 02488149 2004-11-22
Docket No. 027262-195
contemplated, such as helical coil farms, void forms, elliptical, triangular,
rectangular cross-
sections, etc. It is recognized that in some cases, such as in relatively law
load carrying
applications, it is possible for only the reinforcing nbs 1 G to include the
reinforcing member or
material. It is also recognized that each n'b may include more than one
reinforcing member.
[0015] Tho reinforcing raembers are arranged to carry tension and compression
forces.
The area of concrete that can be replaced by 1 square inch of reinforcement is
generally
determined by the ratio of the Young's modules of the two materials. With
steel reinforcements
for example, this ratio is expressed in E steel/iE concrete, which in the case
of polymer concrete
can be in the range of 15 to 30, as compared to normal Portland cement
concrete where the ratio
is typically in the range of 7 to 10. Even though steel is roughly three {3)
times as expensive as
polymer concrete on a per pound basis and roughly nine (9) times more
expensive by volume,
the savings can be significant.
[0016) Referring still to Fig. 1, by utilizing ribs with reinforcing members
18' formed of
reinforcing steel, polymer concrete pipe 10 having a primary wall thickness
of'/,T can be
provided with strength characteristics comparable to a smooth walled concrete
pipe having a
wall thickness ofT, but at a reduction in required concrete of about 20
percent or more (in some
embodiments, about 30-40 percent). This reduction in the amount of required
concrete can
decrease the cost of the polyraer concrete pipe 10 as compared to a comparable
strength smooth
walled pipe.
j0017J In one example, a pipe has an inner diameter D of about 48 inches, a
primary wall
thickness T' is about 2 inches and the reinforcing ribs I6 are {i) spaced
apart a length L of
approximately 12 inches, (ii) raised from the wall portion 14 a height H of
approximately 1.5
inches and (iii} tapered, having a base width W of about 3 inches and a top
width w of about 1.5
inches, (resulting in a trapezoidal-shaped cross-section. Fig. 2 shows a
partial cross-section (wall
and ribs only) for another example of ribbed polymer concrete pipe having a 96
inch inner
diameter and a primary wall thickness T' of about 2.5 inches. The ribs 16 are
spaced apart a
length L of approximately 12 inches, are raised from the wall portion 14 a
height H of
approximately 2.5 inches, are tapered, having a base width W of about 4 inches
and a top width
w of about 1.5 inches. In both illustrated examples of Fig. 1 and 2, the
primary wall portion 14 is
cylindrical (both at its inner and outer surfaces), particularly right
circular, and the ribs 18 extend
circumferentially about the primary wall portion. However, other
configurations far the primary
-3-
CA 02488149 2004-11-22
Docket No. 027262-195
wall portion are contemplated, including non-cylindrical pipe shapes and arch
shapes (for one or
both of the inner and outer surfacts). Accordingly, many variations are
possible.
Reinforcing ribs 16 may be spaced and sized as necessary to provide the needed
reinforcement in the exterior of the pipe. Besides bending tension, the
reinforcement in the
reinforcing rib carries the bending and ring compression loads that otherwise
would have been at
least partially carried by the polymer concrete partion that, in a smooth
walled pipe, would fill
the "valley" (void space) 35 between the ribs.
[0018] Referring now to Figs. 3 and 5, exemplary polymer pipe configurations
using
void form reinforcing members 34 (Figs. 4A-4C) are shown. In the case of each
example, a
unitary tubular member 34 is formed of polymer concrete and has a wall 32. A
void form
reinforcing member 34 is located in the wall to displace polymer concrete and
to provide
compressive and tensile strength. In Figs. 3 and 3A, the reinforcing member 34
is helically
wound to form a coil having a relatively open, constant pitch with polymer
concrete disposed
between the individual turns. Aa above, the void form reinforcing mcmbar can
be of any suitable
configuration that provides the requisite reinforcement for the wall. In
another example, a
polymer concrete pupe such as that shown in Figs. 3 and 3A could utilize a
solid, rod-type
reinforcing member in place of a void form reinforcing member.
[0019) In Fig. 5, the wall 32 includes a primary wall portion 44 and
circumfcrential ribs
42, but a helical rib could also ha used, in which case void form reinforcing
member 34. could
also be helical. In some cases, and as shown by Figs. 3 and 3A, a rib may not
be included.
[0020) The void form reinforcing members can be tubular metal such as steel,
or
possibly tubular fiberglass. Other variations might be used. Referring also to
Figs. 4A-4C, the
void form may have a cross-section that is rectangular, triangular, round, or
some other shape.
[OOZl) Any suitable polymer concrete material can be used to form the polyraer
concrete
pipe. Bxamples of potentially suitable polymer concrete material are described
in U.S. Patent
Nos. 6,448,593; 6,034,155; 4,737,538 and 4,371,639, the disclosures ofwhich
sec hereby
incorporated by reference as if fully set forth herein.
It is to be clearly understood that the above description is inttnded by way
of
illustration and example only and is not intended to be taken by way of
limitation. Other
changes and modifications could be made, including both narrowing and
broadening variations
of the previously described embodiments and examples.
-4_
