Note: Descriptions are shown in the official language in which they were submitted.
2191533
The present invention relates to a wall system
utilizing stacked precast interlocking concrete blocks
which may be joined by a bonding agent. The
structural blocks are adapted for mortarless assembly
with an inner tier of blocks interlocking with an
outer tier of blocks. The respective tiers are each
aligned in horizontal rows and vertical columns, and
are not staggered as in a running bond. Relatively,
however, the respective tiers are offeet laterally and
vertically from one another such that inner and outer
blocks in their interlocked positions are offset
sideways by one half block length and vertically by
one half block height.
The invention further includes a bonding agent
which is adapted to be applied by immersion or dipping
into an emulsion or slurry mixture, and allowed to set
so as to create an integral structural joint between
blocks and to establish a subst~nt;~11y rigid wall
structure In addition, the emulsion or slurry may be
applied by brush to the inner or outer wall surfaces
after a wall or building has been assembled to provide
a seal coat and final bond between the constituent
blocks of the structure.
BackgrD1-n~ of ~P Invontion
In the concrete block industry, precast concrete
blocks are generally of standard modular sizes,
normally having a height of 8" (200 mm), a length of
16" (400 mm) and various modular widths, which vary
depending upon the application in which the blocks are
used. A standard 8" (200 mm) wide block defines the
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prime modular unit, a3 it is particularly proportioned
to achieve a running bond for a wall, which does not
require cutting of blocks. Other modular units of 6"
(150 mm), 10" (250 mm) and 12" (300 mm) wide blocks
are also frequently used. The latter sizes of block,
however, do not exhibiting the 'prime' proportionality
of an 8" modular block, cannot be used to achieve a
true running bond, and require that blocks be cut or
mortar interfilled whenever it is n~R=~ry to
complete any structural corner.
Normal concrete blocks have planar, orthogonal
faces and are bonded with mortar to adjacent blocks to
form a wall. In consequence of the labour and time
constraints imposed by traditional lay up of mortar
bonded concrete blocks, attempts have been made to
design dry stackable blocks for use in wall systems.
Such blocks may include a hollow structure for
~ubsequent infilling with concrete, may utilize
joining clips, or may be interlocking. Various
interlocking blocks have been designed, including
upstanding pintals or tongues which interfit with
gudgeons or grooves in adjoining blocks, as for
example in U.S. Patent 2,610,503 to Hall or in U.S.
Patent 3,618,279 to Sease. Interlocking blocks,
joinable by roas are illustrated in U.S. Patent
932,157 to Matthews. All of these blocks are hollow,
with a central void which will permit subsequent
filling of the void with concrete.
Interlocking block structures have been disclosed
in U.S. Patent 1,356,590 to Baumann, U.S. Patent
3,557,505 to Kaul, U.S. Patent 1,493,811 to Frewen and
21 91 533
in my U.S. Patent 4,633,630 to Rindyiides. Each of
the blocks disclosed in the foregoing patents utilizes
a system of interlocking male and female elements such
as tongues and grooves or similar elements. The
S Baumann, Raul and Rindylides patent all require a
specialized corner block to enable the construction of
an enclosed structure by the orthogcnal alignment of
respective walls. In the Baumann patent, the blocks
are of full wall thickness, whereas in the Raul and
Frewen patents, separate and offset inner and outer
tiers of stacks interlocking blocks are employed. The
Rindylides patent further discloses use of a half
block vertical off~et, in addition to lateral offset
between the blocks of respective inner and outer
tiers.
To date, two tier interlocking block structures
having inner and outer tiers of blocks, such as
illustrated in Frewen, Kaul and Rindylides, have
utilized special corner blocks to enable closure of
the structures. Erewen, which illustrates only a
running length of wall structure, does not disclose
such a corner block and does not address the problem
of closure although such a block is necessary if
closure i9 to be achieved. Kaul is silent on closure
but utilizes a specially adapted full wall width
corner block to enable the construction of orthogonal
wall systems. In addition, in consequence of the
loose interfit of the Kaul connecting arms, a curved
structure, such as a cylindrical silo, may be
constructed. ~nly the Kindylides patent, by the same
inventor as the present application, discloses a two
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tier wall etructure with a specialized outer tier
corner block enabling orthogonal wall structures to be
assembled. ~owever, a separate corner block is
provided for each different thickness of wall, not
only in Xindylides but also in Kaul and inherently 8c
in Frewen.
The wall system of the present invention
eliminates the need for a sp~ri~1;7ed corner block for
each selected th;rkn~s~ of wall, and by the use of a
universal or common corner block, walls of any desired
thickness, within the range of standard block sizes,
can be erected. This versatility allows extra
thickness block frames to be combined with inset block
panels of reduced thickness, incorporating the
structural strength of post and beam frame
construction, and the economies of infilled panels.
When combined with the emulsion or slurry bonding
agent of the present invention, an integral structure
of increased strength and reduced costs may be erected
1lt;1;7;ng the advantages of quickly connected
interlocking blocks and relatively unskilled labour.
The further advantages and economies of the
present invention will be disclosed by reference to
the following description and accompanying drawings
wherein:
Figure lA is a schematic plan view of a closed
block structure using standard 8" modules.
Figure lB is a schematic plan view of a closed
block structure using 6" modules.
Figure 2 is a perspective view of a common
stretcher block according to the present invention.
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Figure 3 is a perspective view of a universal
corner block of the present invention.
Figure 4 is a plan view illustrating blocks of
the present invention, with a common interlock line.
Figure 5 is a plan view illustrating interlocking
of various modular block thicknesses with a common
corner block.
Figures 6-8 are perspective views of a wall
construction according to the present invention
illustrating how the full and half height common
corner and basic stretcher blocks interlock in a
corner construction.
Figure 9 is a simplified perspective view of a
building under construction with the system of the
present invention.
Figure lO is a plan view of an orthogonal wall
structure employing the common modular blocks of the
present invention.
Figure ll is a plan view of an orthogonal wall
structure employing blocks of differential modular
thicknesses in accordance with the present invention.
De~ ed De~cr;ption of ~h~ Invention
A structural wall system in accordance with the
present invention is adapted for use in building
construction. It is assembled by stacking of
interlocking concrete blocks in laterally and
vertically offset inner and outer tiers of rows and
columns of blocks.
2 1 9 ~ 533
In contrast to existing block systems, the
present system permits the closure of an orthogonal
structure assembled from the blocks of the present
system without the requirement to cut or infill
S between blocks. Cutting and tnf;ll;n3 is not an issue
wherein an ideally proportion block is used, such as a
'prime' modular concrete block unit having a length
equal to twice its width and height (i.e.
16"x8"x8"/400x200x200 mm). It does become a problem
where other non-proportional modular blocks are used,
such as a 6" thick block (16" long, 8" high, 6"
thick).
The problem may be illustrated by reference to
Figures lA and lB. In Figure lA, a closed structure
comprised of proportional or prime blocks, such as
16nx8nx8" blocks, is illustrated. A running bond wall
constructio~ permits alternate courses of blocks to be
positioned symmetrically above the joint line of the
course below, and to meet evenly at the corner without
requiring the cutting of blocks. This is a
consequence oi- the width of the block being one half
of the length, i.e. the length is an integral multiple
of the width.
In Figure 1~, a similar sized structure is
illustrated, but using a thinner 6" block. As may be
seen, the second course will not fit evenly in a
running bond over the course below, and require~
cutting of the block in the second course as at points
C2. Alternatively, if the same base dimension D is
~ 2191533
retained, as in Figure lA, then filling of spaces
between blocks as at point F1 in the first course is
required if cutting is to be avoided.
The blocks utilized in the wall system of the
S present invention are similar to the type disclosed
and claimed in my ~AnA~iAn Patent 1,275,359. As may
be seen in Figure 2, a concrete block 10 comprises a
longi~n~inAlly ~t~n~;ng shell 12 having inner and
outer shell faces 14 and 16, respectively. The length
of the shell 12 is nominally twice the height of the
shell. The shell has a thickness which is variable
depending upon the ultimate wall thickness selected,
as will be P~p1A;n~d hereafter. In a prime
proportional block the thickness of a wall constructed
of prime blocks will be one half the length of the
block.
Centred on the longitudinal length of the shell
is a web member 18 which projects from the inner face
of the shell 14 and extends over the median one half
of the length of the block. Tongue and groove type
projections 20 and recesses 22 are provlded on shell
face 14 and on web 18 for mating with corresponding
projections and reces~es on other block in the manner
hereafter described. This permits blocks 10 to be
longitudinally, transversely and vertically
interlocked together with the inner faces of alternate
blocks facing one another.
As previously explained, in the building
industry, there are certain standards or modular sizes
of blocks. The basic fully proportional or 'prime'
concrete block is nl ;nA1ly 16" long, 8" high and 8
8 2 1 9 1 533
thick. Other modular sizes are nl ;n~lly based upon
2" differentials in thickness, namely 6" wide, 10
wide, 12" wide, etc. To close a rectilinear
structure, any block which does not have a length that
is twice the width will require cutting or filling on
alternate courses of blocks.
In the present invention, the wall system
utilizes blocks which provide the modular sizes common
in the industry, including a basic prime or
proportioned stretcher block and a common corner block
which have an effective length of 16 inches, and
height of 8 inches. In wall construction in
accordance with the present invention, half height
blocks are also required, which have the same length,
width and plan but only one half the height of the
full stretcher and common corner block. When a prime
structure block is interlocked with other prime
stretcher blocks they produce a wall 8 inches thick.
The common corner block has a shell of the same
thickness, and produces an 8" corner. In order to
generate walls of different thicknesses, other block
modules are used in which the shell is of a greater or
lesser modular thickness, but the web portion remains
identical. As may be seen in Figure 4, the prime
block 10, for example, with, a nominal 8 inch width
when assembled in a wall, has a shell 12 and a web 18.
A smaller modular block 30 having, for example an
equivalent wall thickness of 6 inches, has a thinner
shell portion 31 than shell 12 but the same web size
of portion 18. Similarly, a larger size modular block
32 or 34, for use in 10~ and 12" thick walls, have
2 1 9 1 533
outer shells 33 and 35 of increased thickness, but use
the common web 18. Figure 4 lllustrates that the
centre lire of interlocking "I" is common for all
blocks. The width of a wall constructed from such
S blocks will be determined by the thickness of the
shell portions 31, 12, 33 and 35, for example, where
blocks 30, 10, 32 and 34 would be used to build 6",
8", 10" and 12'i inch walls respectively, and the
distance from the interlocking centre line "I" to the
outer face of shells 31, 12, 33 and 35 would be 3~,
4", 5" and 6", respectively.
Referring now to Figure 5, it may be seen how
various blocks of equal modular length and web size,
but of varying ~h;rkn~s may be interchangeably
interlocked to construct a wall structure of varying
thickness. At the corner, it may be seen that a so-
called 8" corner block 40 interlocks with so-called 6"
stretcher blocks 30 at each end, and in turn can
interlock with other thickness of blocks.
C~n~ru~tion of W~ll
Figures 6, 7 and 8 illustrate the construction of
a wall and corner unit with the prime stretcher and
common corner blocks of this invention. Commencing
from a level footing, a pair of half height basic
stretcher blocks llA and llB may be positioned to form
a corner with the outer shell face of the blocks at
right angles to one another. Half height blocks 11
are of the same plan configuration as block 10
illustrated in Figure 2, but of only one half the
height (nominally 4"/100 mm). The=bases of a pair of
lo 2 1 9 1 533
right angled walls may then be constructed by laying a
plurality of half height stretcher blocks 11 to the
right of block llB shown in Figure 6 and by laying a
further plurality of half height blocks 11 in
S longitudinally end to end relationship with block llA
shown in Figure 6.
As may be seen in Figure 7, a full height prime
stretcher block lOA is placed in longitudinally and
transversely interlocked relation with half height
10 prime block llB of Figure 6 (block llB is obscured
from view in Figure 7 by blocks stacked on top and in
front of it). The recesses and pro~ections of full
height common corner block 40 are then aligned over
the corresponding mating projections and recesses of
15 half block llA and full height block lOA. Common
corner block 40A is then lowered down 80 that it
interlocks both longitudinally and transversely with
blocks llA and lOA as shown in Figure 7 (block llA is
also obscured from view in Figure 7 by blocks stacked
20 on top and in front of it). When block 40A is in
place, a 90~ corner of opposed interlocking blocks is
established.
Subsequent full height stretcher blocks 10 and
common corner blocks 40 may then be alternatively
25 stacked in respective inner and outer tiers 80 as to
longitudinally, transversely and vertically interlock
the lower halves of the newly stacked full height
blocks in longitudinal overlapping relationships with
the exposed upper portions of full height blocks which
30 have already been installed.
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11
As may be seen from Figure 9, construction of the
wall continues in this manner, leaving a staggered
upper surface along the tops of opposed tiers of
interlocking blocks until the wall reaches its desired
height. A final course of half height block is then
positioned along the tops of the lower tier so as to
level the top surface of the wall. The resulting wall
is securely interlocked longitudinally, transversely
and vertically and thus able to withstand forces which
may damage or destroy structures formed with prior art
blocks.
A particular advantage of the present block
system permits walls of varying thickness to be
constructed, using only the common corner block at all
corners. For illustration purposes, the cross-section
of an orthogonal or cruciform structure is illustrated
in plan in Figure lO n~ ;ng the prime or
proportional stretcher block lO and the common corner
block 40 of the present invention. As may be seen,
using fully proportional blocks, the structure may be
closed without requiring cutting of any blocks or
filling any void spaces. For example, the structure
schematically illustrated in Figure lO can use 8"
effective prime stretcher blocks and the common corner
block ~8") to produce a wall thickness W equal to 8
inches.
In modern construction, however, it may be
desired to take advantage of differential wall
thicknesses and consequent different load bearing
~r~h;lities of such walls depending upon the loads to
be carried by them. A structure embodying a post and
12 2 1 9 1 533
beam or frame type construction with thinner infill
wall panels may be desirable. Consequently, a wall
having a thicker frame area and a thinner panel area
will require the use of different block thicknesses.
Once di~ferent block thicknesses are employed,
the problem arise5 of cutting of blocks and filling of
voids in order to close an orthogonal structure. In
the present invention, however, this problem can be
avoided by using the common corner block at all corner
locations. This avoids the prior art problem of
creating speclalized corner blocks for varying wall
thicknesses, and ensure8 that complete closure of the
orthogonal structure is possible regardless of the
thickness of the modular block used at other locations
in the wall structure such as at infill panels.
As may be seen in Figure 11, a building structure
similar to that of Figure 10 is illustrated by a cross
sectional plan view of the structure. It will be
appreciated that the inner and outer tiers of block
are vertically staggered or offset by one half block
height, but for ease of understanding, cross sectional
hatching has been omitted in Figure 11 ~or the opposed
tier.
At each corner, a proportional, or common corner
block 40 has been used, while between the corners, the
infilled space has been filled with thinner
dimensional modular blocks such that the effective
width w' of the wall is less than the width of the
wall w illustrated in Figure 10. Where blocks 30 are
modular units which combine to generate a 6" thick
2 1 9 1 533
13
wall, it may be seen at the structure illustrated in
Figure 11 has an 8" pilaster or corner post, with 6"
infill panels.
Referring to the left hand side of Figure 11,
S rather than using an undersized block 30 to join with
common corner block gO, a prime stretcher block 10
(shown in dashed outline) may be joined with corner
block 40. This will create an effective pilaster or
post of greater dimension and bearing strength at the
corners. Similarly, correspondingly sized blocks 10
and 40 can be used at ;ntPrnAl corners.
As may al~o be seen from Figure 9, it is
desirable at a corner to alternate the wall which
engages the corner block, thereby allowing a further
interlocking of the corner blocks. In conse~uence, it
will be appreciated that if common corner blocks 40
are used with larger or smaller th; ~kn~ stretcher
blocks such as 30, 32 or 34, a staggered cornerstone
or dove-tail effect may be created.
As a manufactured product, the interlocking
blocks of the present wall system are designed with
very close tolerances, cufficient to permit the blocks
to interlock while m;n;ml7lng accumulating errors from
those tolerance~. The present blocks are designed to
be about 1 mm under the nominal 400 mm length and 200
mm height as well as 1 mm under the nominal thicknesc.
B~NnTNG ~ NT
The present wall system, although dry stackable
to form a solid stable load-bearing wall and
structure, may be enhanced and strengthened by the use
2 1 9 1 533
14
of a bonding agent interacting between the blocks.
Unlike traditional masonry work, wherein a mastic or
mortar compound is trowelled onto block surfaces and
then the block placed into position, the present
system utilizes a bonding slurry or emulsion to adhere
the interlocking blocks.
Traditional concrete block is undercized from the
nominal 16~ longitudinal dimension by a tolerance of
approximately 1/4" a block, thereby permitting
construction of a block wall with a 1/2" mortar joint.
A stiff mortar, capable of bearing-the weight of
several rows of block during the curing process must
be used. Traditionally, this stiff mortar is applied
with a trowel, the block is set in place and tapped
into a level and aligned position, and the excess
mortar struck off. This requires skilled tradesmen
and is a time consuming project.
In contrast, the blocks of the present invention
may be dipped in a tank or trough c~nt~;n;ng the
bonding agent. The bonding agent is an emulsion or
slurry having the consi~tency of paste, which adheres
to and coats the surfaces of a block as it is dipped.
Each block is dipped up to its mid-height prior to
being stacked in the staggered tier courses of the
wall. The emulsion or slurry on the dipped block is
then available to contact the entire exposed area of
the previous block to which the dipped block is then
interlocked.
Given the afull ~nt;oned tolerances of only 1 mm
on these interlocking blocks, the emulsion adhering to
each consecution block is sufficient to virtually fill
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the tolerance gap. Any excess emulsio~ is forced into
the joints between the blocks below or extruded
towards the outer shell faces of the blocks. Such
extruded emuleion may then be spread on the surface of
the block with a brush, thereby sealing the surface
and the joint. In addition, the thin layer of bonding
agent acts as a filler between irregularities in the
surfaces of the interlocking blocks. It will be
apparent that the level of skill required by a worker
to stack a dipped block ie substantially below that
reriuired for a skilled tradesman to mortar and lay up
a traditional concrete block wall.
It has been found that a satisfactory bonding
agent, in slurry or emulsion form, may be compounded
from an aqueous mixture of portland cement, lime,
bentonite, fly ash, sand and an adhesive or glue. For
example, elurry of 55 parts by volume of water, l0
parts portland cement, l0 parts hydrated lime, 5 parts
dry bentonite, 40 parts fly aeh and 40 parts fine sand
(No. 40 seive) and 2 parts glue will, when mixed, form
a wet paste-like substance of the consistency of
yogurt. Fly ash from thermal electric coal hae been
found to be satisfactory. Applicant has also found
that a glue of elastomeric modified polyacrylate is
effective. Such a glue has been manufactured by
Hoechst Chemicals under the trade name Mowiton LDM
3750, and is currently sold by Gehring-Montgomery Inc.
under the trade name MOWILITH LDM 3750. Other acrylic
based elastometric adhesives, such as carpenters glue
will al50 be effective in correct proportions. When a
block is dipped into a flat tank or trough rrnt~;n;ng
2 1 9 1 533
16
the bonding agent, and immersed to a depth in excese
of 4"/l00 mm (i.e. half the height of an 8"/200 mm
block), the emulsion will cling to the sides of the
block to a thickness of over l mm. Such a coating
S carries sufficient emulsion to fill the tolerance
spaces between ad~acent blocks as the wall is erected.
Although there is a tendency for the components
of the slurry to settle out of suspension, the
agitation of dipping each block into the tank
~nt~;ning the slurry is normally sufficient to
inhibit such undesirable settlement. Occasional
remixlng may be appropriate however.
Optionally, the bonding agent can also be brush
applied to the wall surface, either during erection of
the structure or eubsequently, to seal any cracks or
irregularities in the surface and to provide a finieh
coat, similar to a smooth stucco. Additionally, for
ornament, pigments can be added to the honding agent
to provide a coloured finish to the structure.
The emulsion, being aqueous-based, is quickly
absorbed into the block after it has been stacked,
leaving a stiff, rapidly setting bonding agent which
is sufficient to carry the weight of a wall as it is
erected YormaI curing time for cement or mortar is
to be observed, such that the walls should not be
heavily loaded for approximately four days, and an
ultimate stre~gth will be achieved in approximately 28
days.
A wall system erected with the bonding agent of
the present invention becomes an integral structure,
without any ~oint loosenees. Consequently, the wall
17 2 1 9 1 533
is rigid both laterally, longitudinally and
vertically. In fact, it has been found that the
structure is so integral that it is not necessarv to
insert structural lintels over standard doorways and
S windows up to a span of 5 ft. Tests conducted on
structures assembled by this method have established
the bonded wall of the present invention is able to
support a load of over 2500 lbs. on non-relnforced
lintele spanning five feet.
It will be recognized that the voids 24 in the
blocks as illustrated in Figures 2 a~d 3, may be
filled with concrete and reinforcing rods if greater
strength is required at any point.
It will be appreciated that the blocks disclosed
by example herein conform to general industry standard
sizes. Other length and width dimensions may be used
so long as the relative shape and size of the
interlo~k is sufficient to withstand the shear stress
applied to it, and to resist longitudinal and
transverse horizontal loads. Slmilarly, the emulsion
employed in the present invention may be varied
somewhat in its proportions, or precise constituents
by the 3ubstitution of equivalent materials (i.e.
ceramic waste may be substituted for sand), without
departing for the scope of the invention.
