Technical Field
[0001] The present invention relates to composite structural walls, methods to construct
composite structural walls, prefabricated construction modules, e.g. Prefabricated
Prefinished Volumetric Construction (PPVC), and building structures constructed therefrom.
Background of the invention
[0002] Construction of buildings with shear walls cast-in situ on site is known, and widely
used in the industry. As it is a cast-in situ process, formwork and reinforcement
of the shear wall has to be erected before casting with concrete. The curing of concrete
on site is time-consuming and dependent on environmental conditions (e.g. weather
and temperature). After curing the concrete, it is further necessary to remove formwork.
While the cast-in situ method generally provides a monolithic concrete wall that can
withstand high loads and is applicable for most, if not all, types of buildings, this
method is a time and labour intensive construction activity.
[0003] To improve productivity, precast concrete walls and prefabricated construction modules
have been developed and used in the construction industry. The prefabricated walls
and modules are produced in a factory and transported to the building site as needed.
This allows for better control, and reduces variations in the curing process of the
concrete due to environmental factors (e.g. weather and temperature) at the building
site. However, existing methods of joining two side-by-side precast concrete walls
would result in a composite wall that functions as individual walls rather than as
a single or monolithic wall. Similarly, joining precast concrete walls of side-by-side
prefabricated construction modules would result in a composite wall that functions
as individual walls rather than as a single or monolithic wall.
[0004] Consequently, in order to achieve same vertical loading capacity provided by a monolithic
wall constructed from existing cast-in situ methods, a composite wall, i.e. a combined
width of individual walls joined by existing cast-in situ method to form the composite
wall, would have to be thicker than the monolithic wall. Alternatively, in order to
ensure the width of the composite wall, i.e. combined width of individual walls, is
no more than the monolithic wall constructed from cast-in situ methods, vertical load
bearing limit of the composite wall, as well as the height limit of the building structure,
would have to be reduced. Either way poses a restriction to design and construction
of the building, and prevents the building owner from maximising value from the constructed
building.
Summary of the invention
[0005] In a first aspect of the invention, there is provided a method for constructing a
composite structural wall, the method comprises: adjacently arranging a first pair
of wall panels, wherein each wall panel of the first pair of wall panels includes
a first panel body, and at least one first guide attached thereto and protruding from
a first groove formed in the first panel body, wherein adjacently arranging a first
pair of wall panels includes overlapping the first guides of the first pair of wall
panels to form a first channel; inserting a first linking rod into the first channel;
dispensing a first grout into a first gap between the first pair of wall panels, wherein
dispensing a first grout into a first gap includes dispensing the first grout into
the first channel; and curing the first grout to join the first pair of wall panels.
[0006] In an embodiment of the first aspect of the invention, the method further comprises:
vertically-stacking a second pair of adjacently arranged wall panels on the first
pair of wall panels, wherein each wall panel of the second pair of wall panels includes
a second panel body, and at least one second guide attached thereto and protruding
from a second groove formed in the second panel body, wherein vertically-stacking
a second pair of adjacently arranged wall panels on the first pair of wall panels
includes overlapping the second guides of the second pair of wall panels to form a
second channel; inserting a vertical securement rod into the first and the second
channel such that the vertical securement rod have opposite end portions at least
partially inserted into the first and the second channel respectively; dispensing
a second grout into a second gap between the second pair of wall panels, wherein dispensing
a second grout into a second gap includes dispensing the second grout into the second
channel; and curing the second grout to join the second pair of wall panels.
[0007] In an embodiment of the first aspect of the invention, the method further comprises:
inserting a second linking rod into the second channel.
[0008] In an embodiment of the first aspect of the invention, the vertical securement rod
is integral with the first and/or the second linking rod.
[0009] In an embodiment of the first aspect of the invention, dispensing the first grout
includes dispensing the first grout to a level below where the vertical securement
rod is to be inserted to.
[0010] In an embodiment of the first aspect of the invention, each wall panel of the first
and the second pair of wall panels is provided by separate prefabricated construction
modules, adjacently arranging a first pair of wall panels includes adjacently arranging
a first pair of prefabricated construction modules, and vertically stacking a second
pair of adjacently arranged wall panels on the first pair of wall panels includes
vertically stacking a second pair of adjacently arranged prefabricated construction
modules on the first pair of prefabricated construction modules.
[0011] In an embodiment of the first aspect of the invention, each wall panel of the first
and the second pair of wall panels includes a bottom end portion attached to a floor
slab, the method further comprising: inserting a plurality of backing rods between
of the first pair of prefabricated construction modules and floor slabs of the second
pair of prefabricated construction modules to provide a third gap which intersects
the first and the second channel, wherein dispensing a second grout into a second
gap includes dispensing the second grout into the third gap, wherein curing the second
grout to join the second pair of wall panels includes curing the second grout to join
the second pair of prefabricated construction modules to the first pair of prefabricated
construction modules.
[0012] In an embodiment of the first aspect of the invention, each floor slab of the second
pair of prefabricated construction modules includes at least one floor slab guide
attached to each respective floor slab and protruding from each respective floor slab,
wherein overlapping the second guides of the second pair of wall panels to form a
second channel includes overlapping the floor slab guides of the second pair of prefabricated
construction modules to provide the second channel.
[0013] In an embodiment of the first aspect of the invention, the at least one first guide
includes a wire attached to a reinforcement structure embedded in each wall panel.
[0014] In a second aspect of the invention, there is provided a wall panel in a prefabricated
construction module, the wall panel comprising: a panel body; and at least one guide
attached to the panel body and protruding from a groove formed in the panel body,
wherein the guide is adapted to overlap with an adjacent guide of an adjacently-arranged
wall panel to provide a channel for receiving a linking rod therethrough, and wherein
the wall panel is adapted to join to the adjacently-arranged wall panel by grouting
a gap, including the channel, between the wall panel and the adjacently-arranged wall
panel.
[0015] In an embodiment of the second aspect of the invention, the wall panel further comprises
a reinforcement structure embedded in the panel body, wherein the guide is attached
to the reinforcement structure.
[0016] In an embodiment of the second aspect of the invention, the reinforcement structure
is any one selected from the group consisting of a plurality of steel bars, a plurality
of corrugated pipes each adapted to receive a steel bar of a vertically stacked wall
panel, a mesh of steel bars, a mesh of steel wires, and a plurality of steel bars
each attached to a splice connector adapted to receive a steel bar of a vertically
stacked wall panel.
[0017] In an embodiment of the second aspect of the invention, a surface of the panel body,
which includes the groove formed therein, is roughened.
[0018] In a third aspect of the invention, there is provided a prefabricated construction
module comprising: at least one wall panel according to the second aspect of the invention;
and a floor slab attached to a bottom end portion of the wall panel.
[0019] In an embodiment of the third aspect of the invention, the floor slab comprises a
floor slab guide attached thereto and protruding therefrom, wherein the floor slab
guide is adapted to form the channel.
[0020] In a fourth aspect of the invention, there is provided a building structure comprising:
at least one first composite structural wall which comprises: a first pair of wall
panels arranged adjacent to each other, wherein each wall panel of the first pair
of wall panels includes a first panel body and at least one first guide attached thereto
and protruding from a first groove formed in the first panel body, wherein the first
guides of the first pair of wall panels overlap to provide a first channel; a first
linking rod disposed within the first channel; and a first grouting disposed in a
first gap, including the first channel, between the first pair of wall panels, wherein
the first grouting joins the first pair of wall panels.
[0021] In an embodiment of the fourth aspect of the invention, the building structure further
comprises: at least one second composite structural wall which is vertically stacked
on the first composite structural wall and comprises: a second pair of wall panels
arranged adjacent to each other, wherein each wall panel of the second pair of wall
panels includes a second panel body and at least one second guide attached thereto
and protruding from a second groove formed in the second panel body, wherein the second
guides of the second pair of wall panels overlap to provide a second channel; a second
linking rod disposed within the second channel; a vertical securement rod having opposite
end portions at least partially inserted into the first and the second channel respectively;
a second grouting disposed in a second gap, including the second channel, between
the second pair of wall panels, wherein the second grouting joins the second pair
of wall panels.
[0022] In an embodiment of the fourth aspect of the invention, each wall panel of the first
and the second pair of wall panels is provided by separate prefabricated construction
modules.
[0023] In an embodiment of the fourth aspect of the invention, each wall panel of the first
and the second pair of wall panels includes a top end portion attached to a ceiling
slab and a bottom end portion attached to a floor slab, the building structure further
comprising: a plurality of backing rods interposed between ceiling slabs of the first
pair of prefabricated construction modules and floor slabs of the second pair of prefabricated
construction modules to provide a third gap, wherein the second grout is further disposed
in the third gap and joins the second pair of prefabricated construction modules to
the first pair of prefabricated construction modules.
[0024] In an embodiment of the fourth aspect of the invention, each floor slab of the second
pair of prefabricated construction modules includes at least one floor slab guide
attached to each respective floor slab and protruding from each respective floor slab,
and wherein the floor slab guides of the second pair of prefabricated construction
modules overlap to provide the second channel.
[0025] In an embodiment of the fourth aspect of the invention, the vertical securement rod
is integral with the first and/or the second linking rod.
[0026] In an embodiment of the fourth aspect of the invention, the building structure further
comprises a reinforcement structure embedded in each of the first and the second panel
body, wherein the first and the second guide is attached to the respective reinforcement
structure.
[0027] In an embodiment of the fourth aspect of the invention, the reinforcement structure
is any one selected from the group consisting of a plurality of steel bars, a plurality
of corrugated pipes each adapted to receive a steel bar of a vertically stacked wall
panel, a mesh of steel bars, a mesh of steel wires, and a plurality of steel bars
each attached to a splice connector adapted to receive a steel bar of a vertically
stacked wall panel.
[0028] The composite structural wall, joined from the individual wall panels, functions
as a single or monolithic wall and retains the advantages of both existing cast-in
situ and prefabrication methods. The composite structural wall provides the benefits
of precast wall panels including controllable curing of the wall panel, and reduced
time required to construct the composite structural wall and/or join adjacent modules
both horizontally and vertically. The dimensions of the composite structural wall
are similar to a monolithic wall constructed from existing cast-in situ methods and
yet the composite wall of the invention is capable of providing a similar vertical
load bearing capacity as the monolithic wall constructed from existing cast-in situ
methods.
Brief description of the drawings
[0029] The embodiments are described further with the following figures:
Figure 1A shows a perspective view of a construction site with prefabricated construction
modules;
Figure 1B shows a perspective view of a multi-storey building constructed from prefabricated
construction modules;
Figure 2 shows a prefabricated construction module;
Figures 3A - 3D show a method for constructing a composite structural wall;
Figure 4A shows a top cross-sectional view of the adjacent wall panels in Figure 3C;
Figure 4B is a partial close-up view of Figure 4A;
Figures 5A - 5C show perspective views of two pairs of wall panels being vertically
stacked with different sequences of construction;
Figure 6 shows a top cross-sectional view of the composite structural wall with two
rods in each channel;
Figure 7A shows a perspective view of a composite structural wall having an opening
for a door, a floor slab, and a beam structure;
Figure 7B shows an expanded view of the bottom portion of Figure 7A;
Figure 8 shows a side cross-sectional view of a junction at four wall panels, e.g.
bedding joint between two pairs of wall panel in a vertically stacked arrangement;
Figure 9 shows a perspective view of a composite structural wall with an example of
a reinforcement structure in the wall panel;
Figure 10 shows a top cross-sectional view of the composite structural wall in Figure
9;
Figure 11 shows a perspective view of a composite structural wall with embedded corrugated
pipes adapted to receive steel bars into the composite structural wall;
Figure 12A shows a top cross-sectional view of the composite structural wall in Figure
11;
Figure 12B shows a partial close-up view of Figure 12A;
Figure 13 shows a perspective view of a composite structural with splice connectors
which are adapted to receive and connect to vertical steel bars;
Figure 14 shows an example of a wire rope suitable to be used as a guide.
Detailed description of embodiments of the invention
[0030] In the following description, numerous specific details are set forth in order to
provide a thorough understanding of various illustrative embodiments of the invention.
It will be understood, however, to one skilled in the art, that embodiments of the
invention may be practiced without some or all of these specific details. It is understood
that the terminology used herein is for the purpose of describing particular embodiments
only, and is not intended to limit the scope of the invention. In the drawings, like
reference numerals refer to same or similar functionalities or features throughout
the several views.
[0031] Embodiments described in the context of one of the methods or devices are analogously
valid for the other methods or devices. Similarly, embodiments described in the context
of a method are analogously valid for a device, and vice versa.
[0032] Features that are described in the context of an embodiment may correspondingly be
applicable to the same or similar features in the other embodiments. Features that
are described in the context of an embodiment may correspondingly be applicable to
the other embodiments, even if not explicitly described in these other embodiments.
Furthermore, additions and/or combinations and/or alternatives as described for a
feature in the context of an embodiment may correspondingly be applicable to the same
or similar feature in the other embodiments.
[0033] As used herein, the articles "a", "an" and "the" as used with regard to a feature
or element include a reference to one or more of the features or elements.
[0034] As used herein, the term "and/or" includes any and all combinations of one or more
of the associated listed items.
[0035] As used herein, the terms "first," "second," and "third," etc. are used merely as
labels, and are not intended to impose numerical requirements on their objects.
[0036] As used herein, the term "each other" denotes a reciprocal relation between two or
more objects, depending on the number of objects involved.
[0037] The embodiments of the present invention provide a mechanism to connect or join two
(or a pair of) adjacently-arranged wall panels 100, 200 together to form a composite
structural wall 55. In an embodiment, each connecting wall panel 100, 200 is provided
with guides 105, 205 (for example, steel wire loops, or steel wire ropes, or J-connection
loop as shown in Figure 14) at intervals or spaced apart from each other. A portion
of each guide 105, 205 is embedded within the wall panel 100, 200 while another portion
protrudes from the jointing surface. A groove 110, 210 is formed or provided in the
jointing surface of the wall panel 100, 200 to accommodate the guides 105, 205. The
two connecting wall panels 100, 200 are brought close to each other (leaving a gap
30 between the wall panels 100, 200) such that the guides 105, 205 of the wall panels
100, 200 are disposed or overlap to form a channel 25. A linking rod 40 (for example,
a steel bar) is inserted into the channel 25 formed by the guides 105, 205 of the
connecting wall panels 100, 200. The gap 30 between the wall panels 100, 200 is subsequently
in-filled with concrete or grout and cured to form a composite structural wall 55.
The grout should be of a high strength and non-shrink type. High strength grout is
a fluid form of concrete, and is generally made from a mixture of cement, water, graded
fillers and chemical additives. The two wall panels 100, 200 are held in position,
by the linking rod 40 coupling the guides 105, 205, while the grout is dispensed and
cured. This makes it easier for the composite wall 55 to be constructed in a faster
and more efficient manner.
[0038] Embodiments of the present invention provide an innovative connection system to connect
or join two adjacently-arranged wall panels 100, 200 by using guides 105, 205, with
in-fill concrete or grouting 50 to form a composite structural wall system instead
of forming a cast-in situ concrete shear wall in the conventional way. This allows
wall panels 100, 200 to be joined in a horizontal and vertical direction. The wall
panels 100, 200 may be part of separate prefabricated construction modules 5 and provide
a connection means to join a plurality of prefabricated construction modules 5 to
construct a structure. The constructed structure could be a single storey or a multi
storey building with different compartments or modules. Each prefabricated construction
module 5 could be a single habitable unit, e.g. apartment, or part of a single habitable
unit.
[0039] Figure 1A shows an elevated perspective view of a construction site at which a building
structure is being constructed from a plurality of prefabricated construction modules
5, an example of which is shown in Figure 2. Figure 1B shows a multi-storey structure
that may be constructed by vertical stacking of the prefabricated construction modules
5. At least one wall panel 100 of each prefabricated construction module 5 is joined
to another wall panel 200 of an adjacently-arranged prefabricated construction module
5, by in-situ grouting in the middle joint between the wall panels 100, 200, to form
a composite structural wall 55.
[0040] Briefly, without being limited by theory, the composite structural wall 55 is designed
to be built to the Standard Number SS EN 1992-1-1:2008, titled "Eurocode 2: Design
of concrete structures, Part 1-1 General rules and rules for buildings", which is
incorporated by reference herein.
[0041] At the mid-height, the composite wall 55 is to be designed for moment as follows:
wherein
and
l0 = effective length (vertical length of wall) plus slenderness moment f or slender wall, if applicable.
[0042] The composite structural wall 55 may be built to other relevant national standards
as well without deviating from the methods and wall panels 100, 200 disclosed herein.
[0043] In an embodiment where two composite walls 55 are stacked vertically, a bedding joint
is formed between the upper and lower composite walls 55. At the bedding joint, the
composite wall 55 is to be designed for an assumed eccentricity or imperfection of
20 mm. Key or linking bars are placed along the center line of the composite wall
55 and are designed to take moment due to this eccentricity.
[0044] Each composite wall 55 may be a shear wall of the building structure. Each composite
wall 55 is designed as one element to take into account the design value of the applied
axial or vertical force in the z-direction (N
Ed), bending moment in the x-direction (M
Ed,xx), and y-direction (M
Ed,yy), as shown in Figures 3A - 3D. The illustrated x, y, and z directions are perpendicular
to each other to represent a three-dimensional axis.
[0045] In Figure 3A, a wall panel 100 is shown. The wall panel 100 comprises a panel body
101 which is provided with at least one groove 110 (on a surface of the panel body
101), and at least one guide 105 protruding from the at least one groove 110. The
wall panel 100 in Figure 3A is shown to have two grooves 110 each having three guides
105, but it is to be appreciated that other number of grooves 110 and/or guides 105
are possible in various embodiments. The position and number of grooves 110 and guides
105 are dependent on the required load bearing capacity and dimensions of the composite
structural wall 55.
[0046] In an example, the wall panel 100 has two grooves 110, wherein two guides 105 protrude
from each groove. The guides 105 may be arranged near the ends of each groove 110
(i.e. top and bottom of the panel body) or at other suitable positions. In another
example, in addition to having two guides in each groove, a third guide 105 may be
provided near the middle portion of the panel body. In another example where the composite
structural wall may be of a smaller dimension and load bearing capacity, a single
groove 110 and guide 105 may suffice.
[0047] In various embodiments, the wall panel 100, 200 may be a precast concrete wall, i.e.
the wall panel 100, 200 is fabricated at a site other than the actual site for constructing
a building structure e.g. multi-storey building.
[0048] In Figure 3B, a pair of wall panels 100, 200 is shown and includes wall panel 100
of Figure 3A and another wall panel 200. Wall panel 200 comprises a panel body 201
which is provided with at least one groove 210 formed on a surface of the panel body
201, and at least one guide 205 protruding from the at least one groove 210. Both
wall panels 100, 200 may have similar or complementary structure and features. When
the pair of wall panels 100, 200 are adjacently arranged as shown in Figure 3B, guides
105, 205 of both wall panels 100, 200 overlap to form a channel 25 which allows one
or more linking bars 40 to be subsequently inserted there into (see Figures 4A, 4B
and 6).
[0049] In an embodiment where guides 105, 205 are arranged at the same height, the guides
105, 205 may have some flexibility to allow bending to form the channel 25 when the
wall panels 100, 200 are adjacently arranged as shown in Figure 3B.
[0050] In an embodiment where guides 105, 205 are arranged at different heights, the guides
105, 205 may be arranged in overlapping contact when wall panels 100, 200 are adjacently
arranged as shown in Figure 3B. Alternatively, the overlapping guides 105, 205 may
have a vertical gap therebetween.
[0051] In an embodiment, the guides 105, 205 are fabricated from flexible high strength
steel wires. The guides 105, 205 are attached to the wall panel 100, 200 with a portion,
e.g. circular, semi-circular, arc, loop, protruding from the wall panel 100, 200.
The semi-circular portion of the guides 105, 205 is adapted to form the channel 25
and receive a first linking rod 40 and vertical securement rod 45. The guides 105,
205 may be attached to the wall panel 100, 200 during the fabrication of the wall
panel. As an example, the guides 105, 205 may be formed by making a loop with a steel
wire, with a portion of the loop embedded in the wall panel 100, 200 and the remaining
portion protruding from the surface of the wall panel 100, 200 as shown in Figures
4A and 4B. Two ends of the steel wire may be joined by a connector or cramp to form
the loop. Alternatively, the two ends are tied together, or placed in close proximity,
as shown in the J-connection loop of Figure 14, to be embedded within the wall panel
with the loop or circular or oval portion of the steel wire protruding from the wall
panel to form the channel 25. The steel wires may have a tensile strength equal to
at least 2.5% of the induced vertical load of the wall panel 100, 200. The tensile
strength of the wall panels 100, 200 depends, at least in part, on the number of guides
105, and may be varied accordingly.
[0052] A method for constructing a composite structural wall 55 and/or building structure,
is shown in Figures 3A - 3D and described below.
[0053] The method comprises providing a wall panel 100 (Figure 3A), adjacently arranging
a first pair of wall panels 100, 200 with a first gap 30 therebetween (Figure 3B).
This step includes overlapping the guides 105, 205 (or first guides) of the first
pair of wall panels 100, 200 to form a first channel 25. The first gap 30 includes
the space provided by the grooves 110, 210 (or first grooves) facing each other and
the first channel 25 as seen most clearly in Figures 4A and 4B. The first gap 30 further
includes a space formed between facing non-grooved surfaces of the wall panels 100,
200.
[0054] The method further comprises inserting a first linking rod 40 into each first channel
25 (Figure 3C) to couple the wall panels 100, 200. The first linking rods 40 should
be of sufficient length to pass through the guides 105, 205 of both wall panels 100,
200. In an embodiment, the length of the first linking rod 40 is approximately or
at least the whole longitudinal length of the at least one groove 110, 210.
[0055] The method further comprises dispensing a first grout into the first gap 30 (Figure
3D) while the first linking rods 40 couple the wall panels 100, 200.
[0056] The method further comprises curing and/or hardening the first grout to form a sealant
50 to join the first 100 and second wall panel 200 and thereby forming the composite
structural wall 55 (Figure 3D). The composite structural wall 55 constructed therefrom
would behave as a monolithic structural wall and has increased load bearing capacity
as compared to a similarly dimensioned composite wall formed from two precast concrete
walls using traditional cast-in situ methods.
[0057] Figure 4A shows a top cross-sectional view of the first pair of wall panels 100,
200 corresponding to Figure 3C while Figure 4B shows an expanded view of Figure 4A,
particularly the grooves 110, 210 and first channels 25 with the first linking rod
40 inserted. The above-described method according to the invention produces a horizontal
connection between adjacent wall panels 100, 200 to form a composite structural wall
55. When the wall panels 100, 200 form part of separate prefabricated construction
modules 5, the invention allows horizontal securement or joining of horizontally adjacent
prefabricated construction modules 5.
[0058] The invention further allows vertical securement or joining of vertically adjacent
composite structural walls 55 or prefabricated construction modules 5. Accordingly,
the above-described method for constructing a composite structural wall 55 and/or
building structure, as shown in Figures 3A - 3D may be suitably modified as described
below and shown in Figure 5A.
[0059] Continuing from the above-described method with reference to Figures 3A to 3C, the
method further comprises vertically stacking a second pair of adjacently arranged
wall panels on the first pair of wall panels (see Figure 5A). This step includes overlapping
the guides (or second guides) of the second pair of wall panels to form a second channel.
At least in some embodiments, the wall panels of the second pair may have similar
or identical configuration as the wall panels of the first pair and therefore the
details of wall panels 100, 200 would apply correspondingly to the second pair of
wall panels.
[0060] The method further comprises inserting a vertical securement rod 45, through the
second channel and partially into the first channel 25, such that a lower end of the
vertical securement rod 45 is at least partially inserted into the first channel and
overlaps with a portion of the first linking rod 40 (see Figure 5A). The overlapped
portion is known as the lap length and allows for the vertical loads to be transferred
between the first linking rod 40 and vertical securement rod 45. The grooves and channels
of the first and of the second pair of wall panels 100, 200 should preferably be aligned
in a substantially linear manner for greatest structural strength. Figure 5A shows
the vertical securement rod 45 disposed in the second channel while the second pair
of wall panels, together with vertical securement rod 45, are being stacked upon the
first pair of wall panels. Alternatively, the vertical securement rod 45 may be inserted
into the second and first channels after the second pair of wall panels are stacked
on the first pair wall panels.
[0061] The method further comprises dispensing a second grout into a second gap between
the second pair of wall panels, wherein dispensing a second grout into a second gap
includes dispensing the second grout into the second channel.
[0062] Modifications may be made to the above-described method described with reference
to Figure 5A and possible modifications are described but are not limited to the following.
[0063] In one embodiment, after stacking the second pair of wall panels on the first pair
of wall panels and after inserting a vertical securement rod 45 through the second
channel and partially into the first channel 25, but before dispensing the second
grout into the second gap, the method further comprises inserting a second linking
rod 47 into the second channel. The second linking rod 47 may be of sufficient length
to pass through the second guides of the second pair of wall panels. In an embodiment,
the length of the second linking rod 47 is approximately or at least the whole longitudinal
length of the second channel.
[0064] In one embodiment, the vertical securement bar 45 is inserted into the first channel
25 prior to dispensing and curing the first grout, and also prior to vertically stacking
the second pair of adjacently arranged wall panels on the first pair of wall panels.
In one example of this embodiment (see Figure 5B), a second linking rod 47 may be
present in the second channel at the second pair of wall panels while the second pair
of wall panels, together with second linking rods 47, are being stacked on the first
pair of wall panels. In another example of this embodiment (see Figure 5C), second
linking rods 47 may be absent in the second channel at the second pair of wall panels
while the second pair of wall panels are being stacked on the first pair of wall panels.
Thereafter, the second linking rods 47 may be inserted into the second channel.
[0065] In one embodiment, the vertical securement bar 45 may be inserted into the first
channel 25 after the first grout is dispensed but before the first grout has cured
completely. Whereas in another embodiment, the first grout is dispensed to a level
below where the vertical securement rod 45 is to be inserted to, e.g. below the lap
length. In other words, only the non-overlapping portion of the first linking rod
40 or non-lap length portion is grouted; the overlapping portion of the first linking
rod 40, i.e. lap length, and the corresponding portion with respect to the first channel
25 and the first gap 30 remain ungrouted for the time being. This has an advantage
that the first grout dispensed may be allowed to cure without a need to quickly or
immediately stack the second pair of wall panels and insert the vertical securement
rod 45 into the first channel 25 before the first grout cures completely. In due course,
after the first grout has cured, the second pair of adjacently arranged wall panels
are stacked onto the first pair of wall panels, the vertical securement rod 45 is
inserted into the second channel, a second grout is dispensed into the portion of
the first channel 25 and gap 30 not filled by the first grout previously, and also
into the second channel. It will be apparent that the second channel may be partially
filled with the second grout, e.g. dispensed to a level below a subsequent overlap
length to accommodate the third or subsequent pair of wall panels and its vertical
securement rod.
[0066] In one embodiment, the vertical securement rod 45 may additionally serve as the first
40 and/or second linking rod 47. In one example, the vertical securement rod 45 is
integral with or forms part of the first linking rod 40. In another example, the vertical
securement rod 40 is integral with or forms part of the second linking rod 47. In
yet another example, the vertical securement rod 45 is integral with or forms part
of both the first 40 and the second linking rod 47. Whereas in another embodiment,
the vertical securement rod 45 is only inserted partially into both the first channel
25 and the second channel. In various embodiments, the first linking rod 40, second
linking rod 47, and/or vertical securement rod 45 may be steel rods.
[0067] To further increase the height of the building structure, further pairs of wall panels
can be vertically stacked as described above, i.e., a third pair of adjacently arranged
wall panels are stacked, in a vertical or upward direction, upon the second pair of
joined wall panels, a fourth pair of adjacently arranged wall panels are vertically
stacked on the third pair of joined wall panels, and so on.
[0068] In some embodiments, the wall panels 100, 200 form part of separate prefabricated
construction modules 5. Accordingly, references to adjacently arranging wall panels
100, 200 and vertically stacking adjacently arranged wall panels include, respectively,
adjacently arranging prefabricated construction modules and vertically stacking adjacently
arranged prefabricated construction modules.
[0069] In an embodiment, the first channel 25 formed by the guides 105, 205 should be suitably
sized to receive the first linking rod 40 as well as the vertical securement rod 45
to allow a second set of wall panels to be vertically stacked upon the first pair
of wall panels. Figure 6 shows a top cross-sectional view of the composite structural
wall 55 with the first linking rod 40 and vertical securement rod 45 in the first
channel 25.
[0070] In an embodiment, the at least one groove 110, 210 may be of suitable dimensions
to at least accommodate the protruded portion of the at least one guide 105, 205.
In an embodiment, the combined depth of facing grooves 110, 210 (Figure 6, two of
w
2) and the size of the gap 30 (Figure 6, w
3) may be slightly larger than the protruded portion of the at least one guide 105,
205. This minimises the dimensions of the structural composite wall 55 and the amount
of grouting needed.
[0071] In an embodiment, each wall panel 100, 200 is attached to a floor slab 15 (Figure
7A and 8). Each floor slab 15 may further comprise a slab guide 115 or 215. The slab
guide 115, 215 is similar to the guides 105, 205 in that the slab guides 115, 215
of adjacent floor slabs 15 are disposed in an overlapping arrangement to form the
channel e.g. first channel 25. A portion of each slab guide 115, 215 is embedded within
a substantial length of the floor slab to provide the continuity of slab reinforcement.
Similar to guides 105, 205, the slab guide 115, 215 may be a high strength steel wire
rope. In an embodiment, the slab guide 115, 215 has a higher tensile strength than
the guide 105, 205 to provide reinforcement for the floor slab 15. In an embodiment,
the floor slab 15 is further attached to a beam structure 17 to provide additional
structural strength as shown in Figure 7B. Figure 7B shows the composite structural
wall 55 formed with attached floor slabs 15 and beam structures 17.
[0072] In an embodiment, each wall panel 100, 200 in respective prefabricated construction
modules 5 is further attached to a ceiling slab 10. In other words, opposed end portions
of each wall panel are respectively attached to a ceiling slab 10 and a floor slab
15 (Figure 2). Alternatively, the floor slab 15 of the upper module 5 may serve as
the ceiling of the lower module.
[0073] In an embodiment, backing rods 130, 230 are inserted or interposed between the first
pair of prefabricated construction modules (optionally, ceiling slab 10 thereof) and
floor slabs 15 of the second pair of prefabricated construction modules to provide
a third gap which intersects the first and the second channel (Figure 8). Grout is
dispensed to fill the third gap to join the first to the second pair of prefabricated
construction module or floor slab 15 of the second pair of prefabricated construction
module to the ceiling slab 10 of the first pair of prefabricated construction module.
The backing rods 130, 230 prevent leakage of grout and when the grout is cured, the
bedding joint is formed. The backing rods 130, 230, the first pair of prefabricated
construction module or ceiling slab 10 thereof and floor slab 15 of second pair of
prefabricated construction module may form an enclosed space for receiving grout.
[0074] The wall panel 100, 200 may further comprise a reinforcement structure to provide
structural strength, in particular tensile strength, to the wall panel. The reinforcement
structure may also serve as an attachment or anchoring point for the guide 105, 205
to be attached to, for example by welding or tying. The reinforcement structure may
be embedded within the wall panel 100, 200 during the pre-fabrication process. The
reinforcement structure may be provided as a plurality of steel bars 125, 225, a mesh
of steel bars or wires, or a plurality of corrugated pipes wherein each corrugated
pipe is adapted to receive a steel bar. Figures 4A and 4B show a reinforcement structure
being a plurality of steel bars 125, 225 embedded in the wall panel. Figure 9 shows
a composite wall 55 which is joined from two wall panels 100, 200, each being embedded
with a reinforcement structure comprising of a mesh of steel bars. The mesh comprises
an arrangement of intersecting vertical steel bars 125, 225 and horizontal steel bars
135, 235.
[0075] Figure 10 shows a top cross-sectional view of the composite wall 55 in Figure 9.
Figures 11, 12A and 12B show a plurality of non-intersecting corrugated pipes 140,
240 embedded in the wall panel, wherein each corrugated pipe is adapted or sized to
receive a steel bar.
[0076] In an embodiment, a splice connector 145 (mechanical rebar connector) may be provided
to receive steel bars 125 of vertically stacked wall panels. Figure 13 shows a composite
structural wall 55 wherein in each wall panel, a splice connector 145 is attached
to each steel bar 125 and is adapted to receive and secure to another steel bar of
a vertically stacked wall panel. The attachment of the splice connector 145 to the
steel bars 125 may be by any suitable means, for example by a taper-threaded design,
by welding, or by using grout. Figure 13 shows the splice connector 145, which is
arranged near the upper end of the wall panel 100, attached e.g.welded, to a vertical
steel bar 125 of the wall panel 100 and positioned to receive a vertical steel bar
125 of a vertically stacked or upper wall panel (not shown). As a second (upper) pair
of wall panels are being stacked on a first (lower) pair of wall panels, each vertical
steel bar 125 from the upper wall panel is inserted into a splice connector and may
be secured by a tapered design, welding or grout. The splice connector 145 may alternatively
be arranged at the lower end of the wall panel to receive steel bars of a lower wall
panel.
[0077] Other types of reinforcement structures may also be used alone or in conjunction
with the non-limiting examples described herein. It may be seen from the top cross-sectional
view of the various embodiments that the reinforcement structure would not affect
the method for joining the wall panels.
[0078] A shear resistance check may be performed to determine the structural integrity of
the composite wall 55. The shear resistance would be checked at the interface between
the wall panel 100, 200 and the in-fill grout. The shear resistance could be due to:
- (a) Induced shear force from lateral load in wall minor direction;
- (b) Induced shear force from differential lateral load in wall major direction;
- (c) Induced shear force from frame action in wall minor direction.
[0079] In an embodiment, the surface of the wall panel 100, 200 with the at least one groove
110, 210 may be roughened to provide surface roughness for interface shear transfer.
[0080] In an embodiment, the wall panel 100 is part of a prefabricated construction module
5 as shown in Figure 2. The prefabricated construction module 5 comprises a floor
slab 15, at least one wall panel 100 as described herein, and optionally a ceiling
10 and/or a beam structure 17. The prefabricated construction module 5 may further
comprise at least one end wall 20. The prefabricated construction module is to be
joined to an adjacent prefabricated construction module using the wall panels 100,
200 and the method described herein. The at least one wall panel 100 serves as the
connection means between adjacent prefabricated construction modules 5. Additional
prefabricated construction modules 5 may be stacked on top of a lower pair of prefabricated
construction modules 5 to stack the modules 5 and extend the building structure vertically
upwards as per the addition of the wall panels vertically. For the prefabricated construction
modules 5 to be joined vertically, the channel 25 formed from the wall panels 100,
200 of adjacent prefabricated construction modules should be able to receive a vertical
securement rod 45.
[0081] It will be apparent that the prefabricated construction modules 5 need not be identical,
in particular for the horizontally adjoining prefabricated construction modules 5.
For example, a prefabricated construction module 5 placed at an end of the structure
will typically have one wall panel 100 and two or three end walls 20, whereas a prefabricated
construction module in the center portion of the structure may have two or three wall
panels 100, 200, and one or two end walls 20. The wall panels 100, 200 serve as a
connection means to join the adjoining prefabricated construction modules 5.
[0082] For example, a prefabricated construction module 5 to be placed in the middle of
a structure may have four wall panels 100, 200 for attachment to four other prefabricated
construction modules 5. It will be apparent that other shapes for the prefabricated
construction module 5 could be similarly designed and applied.
[0083] The end wall 20 and wall panel 100 may take on any shape or dimensions as required
and/or have openings for door and/or window fittings as required. The prefabricated
construction module 5 may have an exposed side (i.e. no end wall or wall panel) as
well to allow for different design structures. A plurality of prefabricated construction
modules 5 as described may be joined together to form a structure. The structure may
be a single or multi storey building. The structure may be employed as buildings for
private or commercial use. The structure may possibly be of use as temporary buildings
in events and disaster relief operations, where ease and speed of construction at
the site is important.
[0084] According to one aspect of the invention, a building structure comprises one or more
composite structural walls 55 arranged as a single-storey or multi-storey arrangement.
Each composite structural wall 55 may comprise joined wall panels 100, 200 as described
above, and therefore the corresponding description of wall panels 100, 200 and their
features, including additions, combinations, alternatives, attachments, may be omitted
here. Each of the wall panels 100, 200 may form part of separate construction modules
5 as described above and therefore the corresponding description of their features,
including additions, combinations, alternatives, attachments, may be omitted here.
Example 1
[0085] A first 100 and second wall panel 200 is each constructed with a horizontal length
(
l1) of 1200 mm, a width (w
1) of 90 mm (Figure 6). The groove has a depth (w
2) 25 mm and length (
l3) of 100 mm. The wall panel 100 comprises two grooves 110 with centres which are 800
mm apart (
l2). A gap 30 of 20 mm (w
3) between the first 100 and second wall panel 200 is used to illustrate this example
of the composite structural wall 55. The reinforcement structure in the wall panels
100, 200 are steel bars 125, 225 embedded in the panel body 101, 201 along the longitudinal
height of the wall panels 100, 200.
[0086] The composite structural wall of Example 1 has a width or thickness of 200 mm (assuming
grouting width is 20 mm) and has a load bearing capacity similar to a conventional
cast- in situ wall of similar width or thickness. It is to be appreciated that other
grouting width or gap width is equally possible.
Example 2
[0087] In this example of the composite structural wall 55, the reinforcement structure
in the wall panels 100, 200 is a mesh of horizontal 135, 235 and vertical steel bars
125, 225 (Figure 9 and 10). The wall panels 100, 200 constructed with a length (
l1) of 1000 mm, a width (w
1) of 140 mm, and a similar groove as in Example 1. The wall panel 100 comprises two
grooves 110 with centres which are 600 mm apart (
l2). The gap 30 between the first 100 and second wall panel 200 is 20 mm. Optionally,
corrugated pipes 140, 240 or splice connectors 145 may be used in combination with
the steel bars 125.
Example 3
[0088] A prefabricated construction module 5 is constructed as in Figure 2 with a wall panel
100 as in Example 1, a floor slab 15 with a thickness of 130 mm, an end wall 20 with
a width of 150 mm, and a ceiling slab 10 with a 50 mm x 50 mm hollow section size
spaced at 600 mm centre to centre.
[0089] Embodiments of the invention as described herein allow for horizontally adjacent
wall panels or prefabricated construction modules to be supported relative to each
other via linking rods while grouting is dispensed and cured. This reduces construction
time and labour requirements and therefore reduces construction costs. Embodiments
of the invention allow vertically stacked wall panels or prefabricated construction
modules to be supported relative to each other via a vertical securement rod while
grouting is dispensed and cured.
[0090] With the invention, pre-cast wall panels 100, 200 and prefabrication construction
modules 5 can be assembled into a building structure more quickly and efficiently
at a construction site. The wall panels 100, 200 and construction modules 5 may be
fabricated in the factory while the foundation works at the construction site are
on-going, thereby reducing the construction cycle time and leading to increased productivity.
Furthermore, the quality of the wall panels 100, 200 and construction modules 5 are
improved due to the controlled environment they are prepared in. Furthermore, a composite
structural wall 55 constructed using the present invention would behave as a monolithic
wall and therefore would be able to achieve similar load-bearing capacity as a monolithic
wall constructed from existing cast-in situ method and having similar width dimensions
or thickness. Accordingly, it will be appreciated that the invention will lead to
reduction in construction costs while increasing productivity and economic benefits.
[0091] Whilst there has been described in the foregoing description preferred embodiments
of the invention, it will be understood by those skilled in the field concerned that
many variations or modifications in details of design or construction may be made
without departing from the present invention.
1. A method for constructing a composite structural wall, the method comprises:
adjacently arranging a first pair of wall panels, wherein each wall panel of the first
pair of wall panels includes a first panel body, and at least one first guide attached
thereto and protruding from a first groove formed in the first panel body, wherein
adjacently arranging a first pair of wall panels includes overlapping the first guides
of the first pair of wall panels to form a first channel;
inserting a first linking rod into the first channel;
dispensing a first grout into a first gap between the first pair of wall panels, wherein
dispensing a first grout into a first gap includes dispensing the first grout into
the first channel; and
curing the first grout to join the first pair of wall panels.
2. The method according to claim 1 further comprises:
vertically-stacking a second pair of adjacently arranged wall panels on the first
pair of wall panels, wherein each wall panel of the second pair of wall panels includes
a second panel body, and at least one second guide attached thereto and protruding
from a second groove formed in the second panel body, wherein vertically-stacking
a second pair of adjacently arranged wall panels on the first pair of wall panels
includes overlapping the second guides of the second pair of wall panels to form a
second channel;
inserting a vertical securement rod into the first and the second channel such that
the vertical securement rod have opposite end portions at least partially inserted
into the first and the second channel respectively;
dispensing a second grout into a second gap between the second pair of wall panels,
wherein dispensing a second grout into a second gap includes dispensing the second
grout into the second channel; and
curing the second grout to join the second pair of wall panels.
3. The method according to claim 2, further comprising:
inserting a second linking rod into the second channel.
4. The method according to any of claims 2 to 3,
wherein each wall panel of the first and the second pair of wall panels is provided
by separate prefabricated construction modules,
wherein adjacently arranging a first pair of wall panels includes adjacently arranging
a first pair of prefabricated construction modules, and
wherein vertically stacking a second pair of adjacently arranged wall panels on the
first pair of wall panels includes vertically stacking a second pair of adjacently
arranged prefabricated construction modules on the first pair of prefabricated construction
modules.
5. The method according to claim 4,
wherein each wall panel of the first and the second pair of wall panels includes a
bottom end portion attached to a floor slab,
the method further comprising:
inserting a plurality of backing rods between of the first pair of prefabricated construction
modules and floor slabs of the second pair of prefabricated construction modules to
provide a third gap which intersects the first and the second channel,
wherein dispensing a second grout into a second gap includes dispensing the second
grout into the third gap,
wherein curing the second grout to join the second pair of wall panels includes curing
the second grout to join the second pair of prefabricated construction modules to
the first pair of prefabricated construction modules.
6. A wall panel in a prefabricated construction module, the wall panel comprising:
a panel body; and
at least one guide attached to the panel body and protruding from a groove formed
in the panel body, wherein the guide is adapted to overlap with an adjacent guide
of an adjacently-arranged wall panel to provide a channel for receiving a linking
rod therethrough, and wherein the wall panel is adapted to join to the adjacently-arranged
wall panel by grouting a gap, including the channel, between the wall panel and the
adjacently-arranged wall panel.
7. The wall panel according to claim 6 further comprising:
a reinforcement structure embedded in the panel body, wherein the guide is attached
to the reinforcement structure, wherein the reinforcement structure is any one selected
from the group consisting of a plurality of steel bars, a plurality of corrugated
pipes each adapted to receive a steel bar of a vertically stacked wall panel, a mesh
of steel bars, a mesh of steel wires, and a plurality of steel bars each attached
to a splice connector adapted to receive a steel bar of a vertically stacked wall
panel.
8. The wall panel according to any one of claims 6 to 7, wherein a surface of the panel
body, which includes the groove formed therein, is roughened.
9. A prefabricated construction module comprising:
at least one wall panel according to any one of claims 6 to 8; and
a floor slab attached to a bottom end portion of the wall panel.
10. A building structure comprising:
at least one first composite structural wall which comprises:
a first pair of wall panels arranged adjacent to each other, wherein each wall panel
of the first pair of wall panels includes a first panel body and at least one first
guide attached thereto and protruding from a first groove formed in the first panel
body, wherein the first guides of the first pair of wall panels overlap to provide
a first channel;
a first linking rod disposed within the first channel; and
a first grouting disposed in a first gap, including the first channel, between the
first pair of wall panels, wherein the first grouting joins the first pair of wall
panels.
11. The building structure according to claim 10, further comprising:
at least one second composite structural wall which is vertically stacked on the first
composite structural wall and comprises:
a second pair of wall panels arranged adjacent to each other, wherein each wall panel
of the second pair of wall panels includes a second panel body and at least one second
guide attached thereto and protruding from a second groove formed in the second panel
body, wherein the second guides of the second pair of wall panels overlap to provide
a second channel;
a second linking rod disposed within the second channel;
a vertical securement rod having opposite end portions at least partially inserted
into the first and the second channel respectively;
a second grouting disposed in a second gap, including the second channel, between
the second pair of wall panels, wherein the second grouting joins the second pair
of wall panels.
12. The building structure according to any of claims 10 to 11 wherein each wall panel
of the first and the second pair of wall panels is provided by separate prefabricated
construction modules.
13. The building structure according to claim 12,
wherein each wall panel of the first and the second pair of wall panels includes a
top end portion attached to a ceiling slab and a bottom end portion attached to a
floor slab, the building structure further comprising:
a plurality of backing rods interposed between ceiling slabs of the first pair of
prefabricated construction modules and floor slabs of the second pair of prefabricated
construction modules to provide a third gap,
wherein the second grout is further disposed in the third gap and joins the second
pair of prefabricated construction modules to the first pair of prefabricated construction
modules.
14. The building structure according to claim 13,
wherein each floor slab of the second pair of prefabricated construction modules includes
at least one floor slab guide attached to each respective floor slab and protruding
from each respective floor slab, and
wherein the floor slab guides of the second pair of prefabricated construction modules
overlap to provide the second channel.
15. The building structure according to any of claims 11 to 14, wherein the vertical securement
rod is integral with the first and/or the second linking rod.