Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02331237 2001-O1-17
Partially :Prefabricated Waffle Slab
FIELD OF THE INVENTION
This presented invention relates to partially prefabricated waffle slabs
especially
'_~ for the purpose of installing equipment which produces wafers in a wafer
foundry. (Said
invention is also suitable for structures of other purposes). Said partially
prefabricated
waffle slabs will meet requirerr~ents in achieving field safety, reasonable
cost, rapid
production, transportation needs, easy installation, and simple structural
joints.
1C~ PROBLEM THE PRESENT INVENTION AIMS TO SOLVE
As the semi-conductor market changes rapidly, construction of a wafer foundry
("Fab") must be very efficient, so that construction and performance testing
can be
completed which allows production to commence within set schedule to ensure
profit.
As required by these delicate equipment, the Fab floors must be able to
withstand
1 ~~ microvibrations. The slabs are the so-called waffle slabs. Waffle slabs,
which are
supported by main pillars, can be used in Fabs and other structures where
resistance of
microvibrations or wide spans is required.
In the conventional Fab waffle slab construction, the construction platform
must
be set up first, then placing the pre-assembled wooden molds on the
construction platform.
2C~ After the wooden molds are secured in place the reinforced steel bars are
arranged, finally
topped with concrete to obtain a waffle slab. Wafer production equipment can
be
installed after the installations of rigidly shaped elevated floors. The
multiple holes of
the waffle slabs are designed to provide air circulation and other mechanical
needs (the
functions of such waffle slab holca are of learned technology, the description
of which is
2~~ therefore not briefed further.)
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CA 02331237 2001-O1-17
Since conventional waffle; slabs are assembled at the construction site,
conditions
like the weather, the elevated construction platform and the mass number of
construction
platforms will affect the construction transportation that will cause delay in
construction
and undermine business opportunity.
:i In order to reduce the impact of weather and the massive number of workers
at the
construction site and to improve quality, prefabrication emerges as the
preferred choice.
But feasibility of such prefabrication will depend on whether requirements for
structural
safety and acceptable cost during the stages of production, transportation,
installation and
assembly can be satisfied. In the past, the prefabrication of waffle slabs,
because of the
complexity in jointing waffle slabs in both the transverse and longitudinal
directions,
coupled by the slab's heavy weiglht, the cost for production, transportation
and installation
would increase significantly. Tlherefore, prefabrication of waffle slabs was
not feasible
in the past, and the problems ~of long construction period and unpredictable
quality
associated with the construction of Fab have persisted.
1 _'i
SOLUTION OFFERED BY OF THE PRESENT INVENTION
The primary objective is 1:o provide a type of partially prefabricated waffle
slabs.
The slabs are partially prefabricated with a bottom plank first, then shipped
to the
construction site for the next phrase of construction. Such partially
prefabrication can
reduce the weight of the waffle slabs to allow easier facilitation of
production,
transportation and installation. Since the concrete topping is poured on site
(second
phase of construction), adjacent slabs can easily be jointed. The bottom
planks of
partially prefabricated slabs are bvuilt strong enough to support the weight
of concrete and
construction dead loads, so the construction platforms, which can affect the
construction
2~~ transportation, are no longer reduired.
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CA 02331237 2004-11-25
The objective is achieved by a type of partially prefabricated waffle slab
that
comprises a main body which comprises of a number of holes for air circulation
and other
mechanical needs.
The main body can also extend forward horizontally to form a bearing plate.
The bearing plate has a number of secondary holes for air circulation and
other
mechanical needs.
The main body is preferably rectangular in shape for easier assembly.
The primary holes of the main bodies are preferably rectangular or circular in
shape for easier facilitation in construction.
The secondary holes of the bearing plate are preferably circular or
rectangular in
shape for easier facilitation in construction.
Four corners of either the main body or the bearing plate are notched, for
continual
of columns.
The main body can also be prefabricated with holes for pillars (or columns) to
pass
through.
In another aspect of the invention, there is provided a partially
prefabricated waffle
slab, comprising at least one main body having a plurality of primary holes
and disk-
shaped plates extending outward horizontally, said disk-shaped plates having a
plurality of
holes and thinner than said main body.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 An isometric view of the main body of the first embodiment.
Fig. 2 An isometric view of the partially prefabricated waffle slabs placed
over
four pillars (or columns), and shows several partially prefabricated waffle
slabs joined together to form a larger waffle slab area ready for second
phase of construction.
Fig. 3 A reflected isometric view of Fig. 2.
Fig. 4 A top view of Fig. 2.
Fig. 5 Front view of Fig. 4
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CA 02331237 2001-O1-17
Fig. 6 Section A-A of Fig. 4.
Fig. 7 Section B-B of Fig. 4, which shows the waffle slab at the
finish of the second .
phase construction.
Fig. 8 Section of Fig. 7 at completion.
:i Fig. Section C-C of Fig. 4, which shows the partially prefabricated
9 waffle slab with
reinforced steel bar cage installed.
Fig. 10 Section of Fig. 6, which shows the H-shaped steel replacing
reinforced bars in
Fig. 9.
Fig. 11 Section of Fig. 10, which shows the waffle slab at the
finish of the second
phase construction.
Fig. 12 A waffle slabs in a second embodiment of the invention.
Fig. 13. A waffle slabs in a third embodiment of the invention.
Fig. 14. A waffle slabs in a fourth embodiment of the invention.
Fig. 15. Section D-D of Fig. 14.
1 _'~ Fig.Jointing of several prefabricated waffle slabs of Fig.
16. 14 .
Fig. 17. A waffle slabs in a fifth embodiment of the invention.
Fig. 18. A waffle slabs in a sixth embodiment of the invention.
Fig. 19. A waffle slabs in a seventh embodiment of the invention.
NUMBERING
SCHEME
OF ELEME',NTS
1, 2 waffle slabs
10, 20 main body
11, 21 primary holes
12, 22 disk-shape plates
13, secondary holes
23
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CA 02331237 2001-O1-17
14 notches
15 reinforced web
18 mufti-cylindrical post connectors
19 cylindrical pillars
:i 24 secondary holes
DETAILED DESCRIPTION OF THE; INVENTION
As shown in Figs. 1 & fi, the partially prefabricated waffle slab I comprises
a
main body 10 and disk-shaped plate 12. Said main body 10 is a rectangular
structure
1(I and having a plurality of primary holes 11. Said primary holes 11 are
rectangular in
shape in this instance of embodiment. The primary holes 11 form reinforced
webs 15
transversely and longitudinally s~o main body 10 is structurally safe. Said
disk-shaped
plate 12 is formed by the extension of main body 10 and is thinner than main
body 10.
The disk-shaped plate is made with number of secondary holes 13, which are in
1 ~~ cylindrical shape. The corners of the disk-shaped plate 12 are also
notched. In Fig. 7, a
mufti-cylindrical post connector 18 made of material like FRP is placed inside
each of the
primary holes 11 of the main bod'r 10; cylindrical pillars 19 made of such
material as FPR
are also placed inside each of secondary holes 13 of the disk-shaped plate 12.
The multi-
cylindrical post connectors 18 and cylindrical pillars 19 are embedded before
20 prefabrication process begins. The reinforced steel bar cage 94 is then
laid in the
transverse and longitudinal directions over the main body 19 (see Fig. 9).
Then second
phase of construction continues vvith pouring concrete. (For easier
understanding, the
reinforced steel bar cage 94, mufti-cylindrical post connectors 18 and
cylindrical pillars
19 are not drawn in Figs. 1 through 5).
25 The waffle slab 1 of a Fab and prefabricated pillars (or columns) 9 will be
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CA 02331237 2001-O1-17
described with illustration Figs. 1 through 5.
As shown in Figs. 2 through 5, several prefabricated pillars (or columns) 9
are
placed at appropriate positions in accordance with the structural needs. Each
pillar 9 has
a capital 91, which forms a supporting area 92 that has larger area than a
capital 91. The
:i notches of corners 14 of said waffle slab 1 are placed on the four pillars
9 at the
corresponding position. A larger area of waffle slab floor is achieved by
jointing several
said waffle slabs 1. The purpose of said notches 14 is for the reinforced bars
90 to pass
through for the continual jointing of pillar 9 (or columns). (For easier
understanding,
Figs. 2-5 show only reinforced bars 90 of one main pillar (or columns)).
Please refer to Figs 2-5 and Fig. 7 for the following discussion of the second
phase
construction of the waffle slabs 1..
While said waffle slabs 1 have been placed to form a larger area of waffle
slab
floor, the steel bars are installed .at the junctures of adjacent slabs. The
second phase of
construction is to pour concrete 95 as the topping. (Fig. 7 shows the
structural view of
1 _'i each waffle slab 1 after the second phase of construction). In Fig. 8,
the surfaces of each
multi-cylindrical post connectors 18 and cylindrical pillars 19 are removed to
form
thorough passage for air circulation and other mechanical needs.
Fig. 10 shows the example of using H-shaped steel 96 to substitute said
reinforced
steel bar cage 94 shown in Fig. 9. In Fig. 11, after concrete 95 is poured,
the top surface
97 of the H-shaped steel 96 remains exposed. By virtue of its rigidity, the
top surface 97
can serve as support of the machines required for the installation of said
rigid shaped
elevated floors. This will prevent concrete on the surface 97 from cracking.
Fig. 12 is the second embodiment of the waffle slab. Said partially
prefabricated
waffle slab lA is different from the partially prefabricated waffle slab 1 of
first
embodiment in that the partially prefabricated waffle slab lA does not have
the disk-
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CA 02331237 2001-O1-17
shape plate and that there are holes 11' surrounding the rectangular primary
holes 11.
Fig. 13 shows the third embodiment of the waffle slab, where the partially
prefabricated waffle slabs 1 B are more similar to the partially prefabricated
waffle slabs
lA of Fig. 12. The difference is that the primary holes 11' of partially
prefabricated
.5 waffle slabs IB are all in circular shape.
Fig. 14 shows the fourth embodiment of the waffle slab. The differences
between
the first embodiment and the fourth embodiment are that the primary holes 21
and the
secondary holes 23 are in circular shape, and the four corners of the fourth
embodiment
are not notched. In the fourth embodiment, said waffle slabs are made with
rectangular
holes 24 in the main body 20 for the continual jointing of major pillars (or
columns);
there are four major pillars (or columns) in this embodiment. Fig. 15 shows
the section
D-D in Fig. 14. Fig. 16 shows a larger waffle slab floor area composed of
several
partially prefabricated waffle slabs 2 of Fig. 14. For constructing the same
area, the span
between the main pillars (or collumns) in the fourth embodiment shown in Fig.
14 is
1 '_~ smaller than the span between pillars (or columns) in the first through
third embodiment,
but this offers another option for the clients when building a Fab.
Fig. 17 shows the fifth err~bodiment. The partially prefabricated waffle slabs
2A
are similar to the partially prefabricated waffle slabs 2 in Fig. 14. The
difference of the
two is that the partially prefabricated waffle slabs 2 in this embodiment do
not have the
20~ disk-shaped plate 12 or 22.
Fig. 18 shows the sixth embodiment. The partially prefabricated waffle slabs
2B
are similar to the partially prefabricated waffle slabs 2 in Fig. 14. The
difference of the
two is that the partially prefabricated waffle slabs 2B have only one
rectangular hole 24
for major pillar (or column) to pass through in the center of main body 20.
Since there is
25 only one rectangular hole 24 for one major pillar (or column) to support,
this embodiment
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CA 02331237 2001-O1-17
allows greater span between pillars (or columns) and the best visual
penetrations when
constructing the same quantity oi' floors.
Fig. 19 shows the seventlh embodiment. The partially prefabricated waffle
slabs
2C are similar to the partially prefabricated waffle slabs 2B in Fig. 18. The
difference is
that the partially prefabricated waffle slabs 2C do not have the disk-shaped
plate 12 or 22.
EFFECTIVENESS OF THE INVEN7C1ON
The partially prefabricated waffle slabs of the present invention have the
advantage of meeting the requirements in achieving field safety, reasonable
cost, rapid
14 production, transportation needs, easy installation, and simple structural
joints and at the
same time complying with the specifications of Fab. A number of partially
prefabricated
waffle slabs can be jointed to form the waffle slab floor large enough for the
Fab.
However, the present invention aloes not place limitations on the shape of the
primary or
secondary holes ~ the presence or absence of the disk-shaped plate ~ the
penetration of
1.'> major pillars (or columns) ~ the notched corners ~ type of reinforcing
method used
or the span between the pillars (or columns). The scope of claims herein
should cover
all feasible technology for partially prefabricated waffle slabs.
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