HOLLOW CORE BLOCK STABILIZATION SYSTEM

SYSTEME DE STABILISATION DE BLOC A AME ALVEOLEE

English Abstract

A system and method of stabilizing wall structures constructed with hollow core cementitious blocks that have not been filled with concrete. Relatively small cores are drilled along either the upper or lower portion of the wall structure to allow for the insertion of a rigid yet flexible reinforcing rod into the hollow core of the block. Through the same hole and other ports drilled into the hollow core block, high density expanding resin is injected to fully fill and encapsulate the reinforcing bar or rod thereby providing sufficient rigidity to the wall structure to withstand significant seismic activity.

French Abstract

Un système et une méthode sont destinés à la stabilisation des structures murales faites de blocs cimentaires à âme creuse qui n'ont pas été remplis de béton. Des trous relativement petits sont percés le long de la portion supérieure ou inférieure de la structure murale pour permettre l'insertion d'une tige de renforcement souple, mais rigide dans l'âme creuse du bloc. Une résine expansible haute densité est injectée dans le trou percé et les autres trous présents dans le bloc à âme creuse afin de remplir totalement et entourer la barre ou la tige de renforcement et assurer à la structure murale la rigidité suffisante pour résister à une importante activité sismique.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of stabilizing a building constructed with a wall comprising a
plurality of
stacked rows of hollow core blocks, the hollow core blocks having cores, the
cores defining a
plurality of hollow channels within the wall, the wall extending from a
foundation to a roof of the
building, the building being stabilized after the roof is in position on the
wall, comprising the
following steps:
drilling ports in hollow core blocks; and
injecting expanding polymer resin through the ports into at least some of the
hollow
channels of the plurality of hollow channels, to fill at least some of the
hollow channels in the
hollow core blocks from the foundation to the roof.
2. The method of claim 1 in which the ports comprise a first port and a
second port into a
hollow channel, the method further comprising inserting a reinforcing rod
through the first port
into the hollow channel and the step of injecting the expanding polymer resin
further comprises
injecting the expanding polymer resin through the second port into the at
least one hollow core
block.
3. The method of claim 1 or 2 in which the expanding polymer resin is a
high density closed
cell expanding polyurethane foam.
4. The method of claim 1, 2 or 3 in which the expanding polymer resin is
not introduced
into each hollow channel.
5. The method of claim 4 in which the expanding polymer resin is injected
into evenly spaced
hollow channels.
6. The method of claim 5 in which the expanding polymer resin is injected
into each second
hollow channel.
6

Description

CA 02594908 2007-07-23
HOLLOW CORE BLOCK STABILIZATION SYSTEM
BACKGROUND
100011 This patent document relates to a system to reinforce cindercrete or
other
cementitious hollow core building blocks used in the construction of walls,
building and other
enclosures or enclosed spaces.
[0002] Many wall structures, typically no more than three stories in height,
are constructed
of cementitious hollow core blocks. Wall structures for schools, industrial
and commercial
buildings, warehouses, and other structures are commonly constructed from such
building
material. The hollow cores are filled with concrete, a loose insulation or are
left hollow.
[0003] Concern has arisen in regard to the stability of structures constructed
with hollow
core blocks located in earth quake prone zones. Since the hollow core blocks
are held together
with only a cementitious grout, there is concern that seismic activity and the
tremors such
activity can create will collapse such rigid cementitious structures.
[0004] Stabilizing existing hollow core block wall structures using
cementitous materials
such as concrete requires much work, which is very intrusive and dirty, and
typically requires
considerable block break-out to allow for the pouring of concrete into the
hollow cores to
provide additional rigidity to the wall structure. Any concrete fill into the
cavity of a hollow
core block will add significant weight to the structure's foundation which was
probably not
designed for such additional loading. Typically as well, a steel reinforcing
bar would be
inserted into the hollow cores which requires further break out of the
structure at the top of the
wall to access the hollow cores to allow for the insertion of the reinforcing
bar.
SUMMARY
[0005] This patent document addresses these and other difficulties with the
prior art.
[0006] There is provided a method of stabilizing structures constructed with
hollow core
blocks. A reinforcing rod is inserted into the hollow core block and expanding
polymer resin
is injected into the hollow core block.
[0007] These and other aspects of the device and method are set out in the
claims, which
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CA 02594908 2007-07-23
are incorporated here by reference.
BRIEF DESCRIPTION OF THE FIGURES
[00081 Embodiments will now be described with reference to the figures, in
which like
reference characters denote like elements, by way of example, and in which:
Fig. 1 is a cross section of a hollow core block.
Fig. 2 is side view of a wall configuration of hollow core blocks;
Fig. 3 is a cross section of a hollow core block filled with expanding polymer
resin;
Fig. 4 is a side view of a wall configuration with ports for supplying
reinforcing
material and polymer resin into the wall; and
Fig. 5 shows a perspective view of three hollow core blocks in the wall
configuration of Fig. 3.
DETAILED DESCRIPTION
[0009] In the claims, the word "comprising" is used in its inclusive sense and
does not
exclude other elements being present. The indefinite article "a" before a
claim feature does
not exclude more than one of the feature being present. Each one of the
individual features
described here may be used in one or more embodiments and is not, by virtue
only of being
described here, to be construed as essential to all embodiments as defined by
the claims.
[0010] Fig. 1 shows a hollow core block 10. The hollow core block 10 is made
of a
cementitious shell 14, which surrounds a hollow core 12. Fig. 2 shows a wall
configuration
using hollow core blocks 10. A foundation 16 supports the hollow core blocks
10. Grout lines
going horizontally and vertically around each hollow core block 10 are filled
with mortar 18.
[0011] Fig. 3 shows a cross section of a treated hollow core block 10.
Expanding polymer
resin 20 fills the hollow core 12 of the hollow core block 10. Reinforcing
rods 22 are placed
within the hollow core 12. The reinforcing rods 22 are held in place by the
expanding polymer
resin 20.
[0012] Figs. 4 and 5 show a wall structure constructed from hollow core blocks
10. Fig. 4
shows ports 24 and 26 through the cementitious shells 14 (Fig. 1) of the
hollow core blocks
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10. Ports 24 may be larger in size than ports 26 to allow the reinforcing rods
22 to be threaded
through ports 26 into the hollow core 12 (Fig. 1) of the hollow core block 10.
Polymer resin
may be injected through the smaller ports 26. Each port may be used to supply
reinforcing
rods 22 into the hollow core 12 or each port may be used to supply expanding
polymer resin
into the hollow core 12, or each port may be used to supply both reinforcing
rods 22 and
supplying expanding polymer resin into the hollow core 12. Although ports 24
and 26 are
shown in different sizes in Fig. 4, all the ports may be constructed with
uniform size. The
ports may also be existing holes in the hollow core block from previous
construction work.
Additionally, the ports may be created perpendicularly into the side of the
blocks, or may be
cut at an angle to assist in introducing the reinforcing rods.
[0013] As shown in Fig. 5, the hollow core blocks 10 may be stacked so that
the hollow
cores 12 define a hollow channel into which the reinforcing rods 22 and
expanding polymer
resin can be supplied. Depending on the height of the hollow channels,
multiple ports may be
provided in each of the hollow channels to provide multiple insertion points
for the
reinforcing rods and the expanding polymer resin. The ports may also be
created at the top of
the wall structure. Access to the hollow channels may also be provided
directly through the
top of the wall structure by removing or partially removing the roof of the
structure. The
reinforcing rods 22 and expanding polymer resin may be introduced directly
into the hollow
channels through the top of the wall if the wall has no roof or if the roof
has been partially
removed. Inserting the reinforcing rods through the top of the wall structure
may provide an
easier method of introduction long lengths of reinforcing rods into the hollow
channels.
[0014] The expanding polymer resin may be delivered into the hollow cores of
existing
cementitious block wall structures by firstly inserting a reinforcing material
through a
relatively small cored hole in the hollow core block and then filling the
hollow core with the
expanding polymer resin through ports which may be no larger than 5/8" in
diameter.
[0015] Depending upon the height of the wall structure, two or more injection
ports may
have to be drilled to access the hollow channel of a stack of hollow core
blocks 10. The high
density expanding resin is then injected into the hollow core and the
aggressive expansive
nature of the resin will fill the cores and encapsulate the reinforcing
material thereby
providing significantly increased rigidity to the wall structure in case of
seismic activity.
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[0016] The reinforcing rods 22 may be any structural support which reinforces
the hollow
channels when the hollow channels are filled with expanding polymer resin. The
reinforcing
rods may be a solid or hollow core synthetic polymer rod, tube, bar, coil or
pipe or may be a
metallic rod, bar, tube, coil or pipe. Other materials and designs may be used
to provide
equivalent structural support.
[0017] Reinforcing rods and expanding polymer resin provide an effective
method of
stabilizing wall structures constructed of hollow core block. There are
additional benefits as a
consequence of using reinforced rods and expanding polymer resin. The
extremely
lightweight nature of the expanding polymer resins does not add significant
weight to an
existing foundation that may not be designed for additional weight loading.
The very high R-
value of the expanding resin will provide additional thermal protection to the
structure.
Additionally, polyurethane foam is an excellent sound inhibitor and as such
will provide
increased sound insulation to treated walls.
100181 Expanding polymer resin, being flexible and not brittle, will not break
under
conditions where hollow or cement filled cementitious blocks will break. For
example, in an
earthquake, blocks may knock against each other and break, rather than swaying
from side to
side. Blocks having hollow channels that are filled with expanding polymer
resin will sway
together as a cohesive structure rather than crumbling into each other.
[0019] The cementitious blocks in this patent application may be any type of
hollow core
block, for example including cement, concrete or cindercrete blocks.
[0020] The ports created in the hollow shells may be created by drilling,
chiseling,
chopping, coring, punching, hammering or any other method. Many different
types of
expanding polymer resin may be used to fill the hollow channels. One example
of expanding
polymer resin is high density closed cell expanding polyurethane foam. Any
method of
injecting the expanding polymer resin may be used.
[0021] When injecting expanding polymer resin into the hollow channels in a
wall,
expanding polymer resin may be introduced into every hollow channel. However,
expanding
polymer resin may not need to be introduced into every hollow channel. For
example, the
expanding polymer resin may be inserted into every second hollow channel to
provide the
necessary additional support for the wall. The number and spacing of the
reinforcing rods may
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depend on the height of the wall. Flexible reinforcing rods may be introduced
to allow
insertion into the side of a wall of hollow core blocks. Reinforcing rods
introduced through
the top of a wall of hollow core blocks need not be flexible. The size of
reinforcing rod able to
be introduced into the wall will be dependant on the size of the ports
created.
100221 Immaterial modifications may be made to the embodiments described here
without
departing from what is covered by the claims.

Representative Drawing