GB2371313A

GB2371313A - Partially prefabricated waffle slab

Info

Publication number: GB2371313A
Application number: GB0101413A
Authority: GB
Inventors: Samuel Yin
Original assignee: RUNHORN PRETECH ENG CO Ltd
Current assignee: RUNHORN PRETECH ENG CO Ltd
Priority date: 2001-01-17
Filing date: 2001-01-19
Publication date: 2002-07-24
Also published as: US20020092249A1; GB0101413D0; CA2331237A1; CA2331237C

Abstract

A waffle slab (1) comprises a main body (10), having number of primary holes (11). Preferably the main body includes a thin, flat lip (12) extending outwardly from the body where the lip has a plurality of holes(13). The main body or the lip may also include pillar holes (24, Figure 18) or notched corners (14) thereby allowing attachment to support pillars.

Description

PARTIALLY PREFABRICATED WAFFLE SLAB

The present invention relates to partially prefabricated waffle slabs especially for the purpose of installing equipment which produces wafers in a wafer foundry. The invention is also suitable for structures of other purposes. Said partially prefabricated waffle slabs will meet requirements in achieving field safety, reasonable cost, rapid production, transportation needs, easy installation, and simple structural joints.

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 so as to allow production to commence within a set schdule to ensure profit.

As required by this delicate equipment, the Fab floors must be able to withstand 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 are required.

In conventional Fab waffle slab construction, the construction platform must be set up first, then the pre-assembled wooden molds are placed on the construction platform. After the wooden molds are secured in place reinforced steel bars are arranged in place, finally topped with concrete to obtain a waffle slab. Wafer production equipment can be installed after the installation 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 holes are well-known in this area of technology, and are therefore not described further).

Since conventional waffle slabs are assembled at the construction site, conditions like the weather, the elevated construction platform and the number of construction platforms will affect the

construction transportation which will cause delay in construction and undermine business opportunities.

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, during 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 weight, the cost for production, transportation and installation would increase significantly. Therefore, prefabrication of waffle slabs was not feasible in the past, and the problems of long construction periods and unpredictable quality associated with the construction of Fab have persisted.

According to the present invention there is provided a partially prefabricated waffle slab comprising of at least one main body having a number of primary holes. The holes being useful for air circulation and other mechanical needs.

Preferably, the main body is substantially rectangular in shape. A rectangular shape being advantageous in allowing for easier assembly.

Additionally, the holes of the main body are preferably substantially rectangular or circular in shape. An advantage being that rectangular or circular shaped primary holes allow for easier facilitation in construction.

In a preferred embodiment the main body has disk-shaped plates capable of extending horizontally outwards.

Preferably, the disk-shaped plates have a plurality of holes.

These secondary holes being useful for air circulation and other mechanical needs.

The secondary holes of said 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 preferably notched. This is useful for continuation of columns.

The main body can also be prefabricated with holes for pillars (or columns) to pass through.

The slabs are partially prefabricated with a bottom plank first, then shipped to the construction site for the next phrase of construction.

Such partial 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 built to be strong enough to support the weight of concrete and construction dead loads, so the construction platforms, which can affect the construction transportation are no longer required.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which : Fig. 1 is a perspective view of the main body according to a first embodiment of the present invention ; Fig. 2 is a perspective view of several partially prefabricated waffle slabs according to the present invention jointed together to form a larger waffle slab area ready for second phase of construction, with one of the partially prefabricated waffle slabs shown placed over four pillars (or columns) ; Fig. 3 is a perspective view of the underneath of the view illustrated in Fig. 2 ; Fig. 4 is a top view of Fig. 2 ; Fig. 5 is a front view of Fig. 2 ; Fig. 6 is a sectional view taken along the dotted line A-A of Fig. 4 ; Fig. 7 is a sectional view taken along the dotted line B-B of

Fig. 4, which shows the waffle slab at the end of the second phase of construction; Fig. 8 is a sectional view of the waffle slab of Fig. 7 at completion ; Fig. 9 is a sectional view taken along the dotted line C-C of Fig. 4, which shows the partially prefabricated waffle slab with a reinforced steel bar cage installed ; Fig. 10 is the same view as Fig. 6 and additionally shows Hshaped steel replacing the reinforced bars of Fig. 9; Fig. 11 shows the view of Fig. 10, with the waffle slab illustrated at the end of the second phase of construction.

Fig. 12 is a perspective view of a waffle slab according to a second embodiment of the invention; Fig. 13 is a plan view of a waffle slab according to a third embodiment of the invention; Fig. 14 is a plan view of a waffle slab according to a fourth embodiment of the invention; Fig. 15 is a sectional view taken along the dotted line D-D of Fig. 14; Fig. 16 is a plan view showing the jointing of several prefabricated waffle slabs of Fig. 14.; Fig. 17 is a plan view of a waffle slab according to a fifth embodiment of the invention; Fig. 18 is a plan view of a waffle slab according to a sixth embodiment of the invention; Fig. 19 is a plan view of a waffle slab according to a seventh embodiment of the invention.

NUMBERING SCHEME OF ELEMENTS 1, 2 waffle slabs 10, 20 main body 11, 21 primary holes 12, 22 disk-shaped plates 13, 23 secondary holes 14 notches 15 reinforced web 18 multi-cylindrical post connectors 19 cylindrical pillars 24 secondary holes.

As shown in Figs. 1 & 6, the partially prefabricated waffle slab 1 comprises a main body 10 and disk-shaped plate 12. The main body 10 is a rectangular structure having a plurality of primary holes 11. The primary holes 11 are rectangular in shape in this embodiment. The primary holes 11 form reinforced webs 15, transversely and longitudinally so that the main body 10 is structurally safe. The disk-shaped plate 12 is formed by the extension of the main body 10 and is thinner than the main body 10.

The disk-shaped plate has a number of secondary holes 13, which are cylindrical in shape. The corners of the disk-shaped plate 12 are also notched. In Fig. 7, a multi-cylindrical post connector 18 made of material like FRP is placed inside each of the primary holes 11 of the main body 10 ; cylindrical pillars 19 made of such material as FPR are also placed inside each of the secondary holes 13 of the disk-shaped plate 12. The multicylindrical post connectors 18 and cylindrical pillars 19 are embedded before the 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 the second phase of construction continues with the pouring of concrete. (For ease of understanding, the reinforced steel bar cage 94, multi-cylindrical post connectors 18 and cylindrical pillars 19 are

now drawn in Figs. 1 through 5).

The waffle slab 1 of a Fab and prefabricated pillars (or columns) 9 will now be described with reference to 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 structural needs. Each pillar 9 has a cap 91, which forms a supporting area 92 that has larger area than the cap 91. The notches 14 in the corners of said waffle slab 1 are each placed on one of the four pillars 9, respectively at corresponding positions. A larger area of waffle slab floor is achieved by jointing several said waffle slabs 1. The purpose of the notches 14 is to allow the reinforced bars 90 to pass through for the continual jointing of pillar 9 (or columns). (For ease of understanding, Figs. 2-5 show only the 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 of construction of the waffle slabs 1.

While the 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 on top. (Fig. 7 shows a structural view of each waffle slab 1 after the second phase of construction). It can be seen in Fig. 8, that the surfaces of each multi-cylindrical post connectors 18 and cylindrical pillars 19 are removed to form a through passage for air circulation and other mechanical needs.

Fig. 10 shows an example of using H-shaped steel 96 as a substitute to the reinforced steel bar cage 94 shown in Fig. 9. As can be seen from Fig. 11, after concrete 95 is poured, the top surface 97 of the Hshaped steel 96 remains exposed. By virtue of its rigidity, the top surface 97 can serve as a support for the machines required for the installation of said rigid shaped elevated floors. This will prevent concrete on the surface 97 from cracking.

Fig. 12 shows a second embodiment of the waffle slab. Said

partially prefabricated waffle slab 1 A is different from the partially prefabricated waffle slab 1 of the first embodiment in that the partially prefabricated waffle slab 1A does not have the disk-shape plate and that there are holes 11'surrounding the rectangular primary holes 11.

Fig. 13 shows a third embodiment of the waffle slab, where the partially prefabricated waffle slab 1 B is more similar to the partially prefabricated waffle slab 1 A of Fig. 12. The difference is that the primary holes 11'of partially prefabricated waffle slab 18 are all in circular shape.

Fig. 14 shows a fourth embodiment of the waffle slab. The differences between the first embodiment and the fourth embodiment are that primary holes 21 and the secondary holes 23 are in circular shape, and that the four corners of the fourth embodiment are not notched. In the fourth embodiment, the waffle slab is 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 a sectional view of the waffle slab of Fig. 14 along the dotted line D-D. Fig.

16 shows a larger waffle slab floor area composed of several partial prefabricated waffle slabs 2 of Fig. 14. For constructing the same area, the span between the main pillars (or columns) in the fourth embodiment shown in Fig. 14 is smaller than the span between pillars (or columns) in the first through third embodiments, but this offers another option for clients when building a Fab.

Fig. 17 shows a fifth embodiment. The partially prefabricated waffle slab 2A is similar to the partially prefabricated waffle slab 2 in Fig.

14. The difference between the two is that the partially prefabricated waffle slab 2 in this embodiment does not have the disk-shaped plate 12 or 22.

Fig. 18 shows a sixth embodiment. The partially prefabricated waffle slab 28 is similar to the partially prefabricated waffle slab 2 in Fig. 14. The difference between the two is that the partially prefabricated waffle slab 2B has only one rectangular hole 24 for the major pillar (or column) to pass through in the centre of main body 20. Since

there is only one rectangular hole 24 for one major pillar (or column) to support, this embodiment allows a greater span between pillars (or columns) and the best visual penetrations when constructing the same quantity of floors.

Fig. 19 shows a seventh embodiment. The partially prefabricated waffle slab 2C is similar to the partially prefabricated waffle slab 2B in Fig. 18. The difference is that the partially prefabricated waffle slab 2C does not have the disk-shaped plate 12 or 22.

The partially prefabricated waffle slabs of the present invention have the advantage of meeting the requirements in achieving field safety, reasonable cost, rapid 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 does not place limitations on the shape of the primary or secondary holes, the presence or absence of the diskshaped plate, the penetration of major pillars (or columns), the notched comers, type of reinforcing method used, or the span between the pillars (or columns). It will be apparent to the person skilled in the art that variations may be made to the waffle slabs as described, hereinbefore, which will still fall within the scope of the present invention as claimed.

Claims

1. A partially prefabricated waffle slabs, comprising at least one main body having a plurality of primary holes.

2. A partially prefabricated waffle slab as recited in claim 1, wherein the main body has disk-shaped plates capable of extending horizontally outwards.

3. A partially prefabricated waffle slab as recited in claim 2, wherein the disk-shaped plates have a plurality of holes.

4. A partially prefabricated waffle slab as recited in any one of claims 1 to 3, wherein the main body is substantially rectangular in shape.

5. A partially prefabricated waffle slab as recited in any one of claims 1 to 4, wherein the holes of the main body are substantially rectangular or circular in shape.

6. A partially prefabricated waffle slab as recited by any one of claims 1 to 5, wherein the main body has at least one pillar or column hole.

6. A partially prefabricated waffle slab as recited in any one of claims 2 to 5, wherein the disk-shaped plate is thinner than the main body.

7. A partially prefabricated waffle slab as recited in any one of claims 3 to 6, wherein the holes of the disk-shaped plate are substantially rectangular or circular in shape.

8. A partially prefabricated waffle slab as recited in any one of claims 2 to 7, wherein the disk-shaped plates are substantially rectangular in shape with the four comers of each disk-shaped plate being notched.

9. A partially prefabricated waffle slab as recited by any one of claims 4 to 7, wherein the four comers of main body are notched.

10. A partially prefabricated waffle slab as recited by any one of claims 1 to 9, wherein the main body has at least one pillar or column hole.

Amendments to the claims have been filed as follows

CLAIMS 1. A partially prefabricated waffle slab, comprising a main body and a bearing plate horizontally extending from said main body, wherein a plurality of holes are installed respectively on said main body and said bearing plate.

2. A partially prefabricated waffle slab as recited in claim 1, wherein the bearing plate is disc-shaped.

3. A partially prefabricated waffle slab as recited in claim 1 or 2 wherein the main body is substantially rectangular in shape.

4. A partially prefabricated waffle slab as recited in claim 1,2 or 3 wherein the holes of the main body and the bearing plate are substantially rectangular or circular in shape.

5. A partially prefabricated waffle slab as recited in any one of claims 1,3 or 4, wherein the bearing plates are substantially rectangular in shape with the four corners of each bearing plate being notched.