FIELD OF INVENTION

The present invention relates to galvanized steel deck and a system thereof for use in the construction industry, and in particular but not exclusively, for use in the construction of buildings such as steel frame buildings, concrete frame building and similar building types.

BACKGROUND TO THE INVENTION

The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known or part of the common general knowledge in any jurisdiction as at the priority date of the application.

Composite construction is widely used in the construction industry due to the benefits it brings. The benefits include structural stability, an increased speed of construction, and savings in weight and size of the primary structure of a building. The combination of concrete and steel when joined together structurally, due to its strength and stiffness, can give rise to an efficient and lightweight design and material.

Composite slabs comprise reinforced concrete cast on top of profiled steel decking, in which the decking typically acts as formwork during construction and as external reinforcement at the composite stage. Hence, it is essential that such steel decking is carefully designed and constructed. However, during the construction stage in which wet concrete is poured over conventional galvanized steel decking, the steal decks of the decking can easily move apart. Furthermore, temporary propping may also be required during the construction stage.

Therefore, there is an urgent need for effective and efficient galvanized steel decking to address the aforementioned disadvantages. The present invention seeks to provide a galvanised steel deck and a system thereof to overcome at least in part some of the aforementioned disadvantages. SUMMARY OF THE INVENTION

Throughout this document, unless otherwise indicated to the contrary, the terms "comprising", "consisting of, and the like, are to be construed as non-exhaustive, or in other words, as meaning "including, but not limited to". In accordance with a first aspect of the present invention, there is provided a metal deck comprising an elongate member having a first portion shaped for receiving a female connector and a second portion shaped for receiving a male connector. The first portion comprises a male connector and the second portion comprises a female connector. The height of the first and second portions lies between approximately 60 mm and 120 mm. The male connector comprises a projection extending outwardly, with a first concave portion connected to a first convex portion and further extends upwardly into a first flange and a second concave portion connected to the base via a second convex portion.

The female connector comprises a corresponding indentation in relation to the male connector and adapted to receive the male connector, with a first concave portion connected to a first convex portion and further extends upwardly into a second flange and a second concave portion connected to the base via a second convex portion.

The male and female connectors are releasably connectable to corresponding connectors on an adjacent metal deck, thereby enabling a plurality of metal decks to be connected to one another, by engaging the first and second concave portions of the male connector and the female connector bearing the corresponding indentation to form positively interlocking metal decking, thereby enabling constant engagement of the male and female connectors and retention of said engagement.

When a female connector of one metal deck is connected to a corresponding male connector of an adjacent metal deck, they are positively interlocked, hence advantageously preventing the connected metal decks from moving apart during the construction stage where wet concrete is poured over the metal decks.

The male connector can take a form of a truncated rectangle with rounded edges and the female connector comprises an indentation that can take the form of a rectangle with rounded edges. The male connector length is shorter than the female connector length. The male connector length lies between approximately 19 mm and 70 mm. The female connector length lies between approximately 20 mm and 72 mm.

The first and second concave parts, adjoining the connectors and the first and second flanges, comprise curved radius of approximately 2.5 mm. Preferably, the margin error for the measurement is approximately + 0.2 mm.

The base of the metal deck comprises at least one trough-shaped portion that extends longitudinally, to prevent oil canning. Preferably, the length of the trough- shaped portion is approximately 38 mm.

The first and second flanges extend generally perpendicular from the base. Each of the first and second flanges that extend upwardly from the connectors comprises a first portion and a second portion. The first portion extends inwardly. The second portion comprises a bent edge that points towards the base of the elongate member. The length of the second portion lies between approximately 8 to 9 mm. The lengths of the first and second flanges lie between approximately 43 mm and 54 mm. Preferably, the margin of error for the measurements is approximately + 5mm. More preferably, the margin of error for the measurements is approximately + 1 to 2 mm.

The metal deck comprises a galvanized coating of Zinc. The combination of the metal deck with concrete provides fire resistance properties.

In accordance with a second aspect of the present invention, there is provided a metal decking system. The metal decking system comprises a plurality of metal decks arranged alongside each other, in which each metal deck comprises an elongate member having a first portion shaped for receiving a female connector and a second portion shaped for receiving a male connector. The first portion comprises a male connector and the second portion comprises a female connector, in which the male and female connectors are releasably connectable to corresponding connectors on an adjacent metal deck thereby enabling a plurality of metal decks to be connected to one another to form a metal decking system.

The male connector releasably connects to a female connector bearing a corresponding indentation in relation to the male connector. The male and female connectors are positively interlocked, thereby enabling constant engagement of the connectors and retention of the engagement.

In accordance with a third aspect of the present invention, there is provided a composite structure comprising a concrete slab and a metal decking, in which the composite structure is clad or embedded in the concrete slab.

In accordance with a fourth aspect of the present invention, there is provided a metal deck substantially as herein described with reference to the accompany drawings as appropriate.

The present invention has at least the following advantages: 1. The present invention prevents the metal decks from moving during the construction stage where wet concrete is poured over the decks.

2. The present invention provides improved mechanical bonding between the metal decks and concrete which results in improved composite performance.

3. Metal decks of the present invention have large spanning ability (span longer distance with a lighter steel weight) as compared to conventional metal decks.

This advantageously removes the need for any temporary or permanent propping during the construction stage.

4. Metal decks of the present invention have improved fire resistance properties as compared to conventional metal decks, and meet the requirements of both local and International Fire Codes.

Other aspects and advantages of the invention will become apparent to those skilled in the art from a review of the ensuing description, which proceeds with reference to the following illustrative drawings of various embodiments of the invention.

BRIEF DESCRIPTION OF DRAWINGS The present invention will now be described, by way of illustrative example only, with reference to the accompanying drawings, of which: Figure 1 shows a profile of a galvanized steel deck in accordance with an embodiment of the present invention;

Figure 2 shows a sectional profile of galvanized steel decks in accordance with an embodiment of the present invention; Figure 3 shows a profile of a galvanized steel deck in accordance with an embodiment of the present invention and its corresponding preliminary load/span results when a theoretical load is applied to the galvanized steel deck;

Figure 4 shows (A) the profile of the galvanized steel deck of Figure 3; and (B) a profile of a plurality of the galvanized steel decks when connected to one another; Figure 5 shows a profile of a galvanized steel deck in accordance with another embodiment of the present invention and its corresponding preliminary load/span results when a theoretical load is applied to the galvanized steel deck;

Figure 6 shows (A) the profile of the galvanized steel deck of Figure 5; and (B) a profile of a plurality of the galvanized steel decks when connected to one another; Figure 7 shows a profile of a galvanized steel deck in accordance with yet another embodiment of the present invention and its corresponding preliminary load/span results when a theoretical load is applied to the galvanized steel deck;

Figure 8 shows (A) the profile of the galvanized steel deck of Figure 7; and (B) a profile of a plurality of the galvanized steel decks when connected to one another; Figure 9 shows a profile of a galvanized steel deck in accordance with yet another embodiment of the present invention and its corresponding preliminary load/span results when a theoretical load is applied to the galvanized steel deck; and

Figure 10 shows (A) the profile of the galvanized steel deck of Figure 9; and (B) a profile of a plurality of the galvanized steel decks when connected to one another. DETAILED DESCRIPTION

Particular embodiments of the present invention will now be described with reference to the accompanying drawings. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. Additionally, unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. The use of the singular forms "a", an", and "the" include both singular and plural referents unless the context clearly indicates otherwise.

The use of "or", "/" means "and/or" unless stated otherwise. Furthermore, the use of the terms "including" and "having" as well as other forms of those terms, such as "includes", "included", "has", and "have" are not limiting. The use of "metal decking" as used herein refers to steel decking, galvanized steel decks or any permanent formwork to concrete for providing structural stability.

With reference to Figures 1 and 2, there is described hereinafter a galvanized steel deck 10 in accordance with an embodiment of the present invention. The galvanized steel deck

10 is for use in the construction of buildings such as steel frame buildings, concrete frame building and the like.

The galvanized steel deck or metal deck 10 comprises an elongate member having a base

11 extending to a first portion and a second portion, the first portion comprises a male connector 12 and the second portion comprises a female connector 13. The galvanized steel deck 10 is one of a plurality of steel decks arranged alongside one another to form steel decking 30. The steel decking 30 is designed for use with concrete topping and to be embedded herein.

The male connector 12 of the galvanized steel deck 10 and the female connector 13 are positively interlocked, enabling constant engagement of the male 12 and female connectors 13 and retention of said engagement. The connectors are releasably connectable to adjacent galvanized steel deck 10. Advantageously, this eliminates the use of securing means to secure the adjacent steel deck 10 together.

The male connector 12 comprises a projection extending outwardly, with a first concave portion 14 connected to a first convex portion 15 and further extends upwardly into a first flange 16 and a second concave portion 17 connected to the base 11 via a second convex portion 18.

The female connector 13 comprises a corresponding indentation in relation to the male connector 12, wherein this inwardly directed portion receives the male connector 12, with a first concave portion 14 connected to a first convex portion 15 and further extends upwardly into a second flange 16 and a second concave portion 17 connected to the base 11 via a second convex portion 18.

The first and second flanges 16 extend generally perpendicular from the base 11. Each of the first and second flanges 16 that extend upwardly from the connectors comprises a first portion 19 and a second portion 20. The first portion 19 extends inwardly. The second portion 20 comprises a bent edge 19 that points towards the base 11 of the elongate member.

Example 1

With reference to Figures 3 and 4, there is described hereinafter a galvanized steel deck 10 in accordance with an embodiment of the present invention.

The galvanized steel deck 10 comprises an elongate member having a first portion shaped for receiving a female connector 13 and a second portion shaped for receiving a male connector 12. The first portion comprises a male connector 12 and the second portion comprises a female connector 13, in which the male and female connectors are releasably connectable to corresponding connectors on an adjacent steel deck thereby enabling a plurality of steel decks 10 to be connected to one another to form a galvanized steel decking system 30 (see Figure 4). When a female connector 13 of one galvanized steel deck 10 is connected to a corresponding male connector 12 of an adjacent galvanized steel deck 10, they are positively interlocked, hence advantageously preventing the connected galvanized steel decks 30 from moving apart during the construction stage where wet concrete is poured over the galvanized steel decks 30.

The dimensions of the galvanized steel deck 10 are collectively chosen to take into account the load to be carried by the steel deck 10. The height of the galvanized steel deck 10 is about 60 mm and the width of the galvanized steel deck 10 is about 300 mm. In other embodiments of the present invention, the height of the galvanized steel deck 10 ranges from about 60 mm to about 120 mm. It would be appreciated that the height and the width of the galvanized steel deck 10 can be lesser than or greater than the measurements or range of measurements mentioned above to suit the needs of the desired composite. Preferably, the margin of error for the measurements is approximately + 5 mm. More preferably, the margin of error for the measurements is approximately + 1 to 2 mm.

Preferred Properties of Galvanized Steel Deck

The preferred properties of the galvanized steel deck 10 comprise the following:

1. Grade of steel used for the galvanized steel deck 10 has high tensile strength that ranges from about 450 to about 550 MPa yield strength.

2. The galvanized steel deck 10 has a base metal thickness that ranges from about 0.75 mm base metal thickness to about 1.50 mm. Preferably, the base metal thickness is about 0.75 mm, about 0.90 mm, about 1.00 mm, about 1.20 mm or about 1.50 mm.

3. The galvanized coating of the steel deck 10 is Z275 min. (275 g/m ) in accordance with AS 1397:2011 Australian Standard.

4. The galvanized steel deck 10 meets the requirements of both local, the Singapore Fire Code and International Fire Codes, which includes the European Fire Code. The galvanized steel deck 10 is embossed on the rib and at the bottom side of the deck for improved diaphragm action.

The galvanized steel deck 10 is subjected to a preliminary load/span testing, which shows the performance of the deck. During the testing, a theoretical load is applied to a galvanized steel deck 10 of a pre-determined steel thickness and a pre-determined slab thickness, and the corresponding span (in mm) is measured (see results table of Figure 3).

Example 2

With reference to Figures 5 and 6, there is described hereinafter a galvanized steel deck 10 in accordance with another embodiment of the present invention. The structure and design of the galvanized steel deck 10 in this embodiment is similar to the galvanized steel deck 10 described in Example 1 and similarly comprises the preferred properties mentioned above (see Figure 6). However, in this embodiment, the height of the galvanized steel deck 10 is about 80 mm.

The galvanized steel deck 10 is similarly subjected to a preliminary load/span testing. During the testing, a theoretical load is applied to a galvanized steel deck 10 of a predetermined steel thickness and a pre-determined slab thickness, and the corresponding span (in mm) is measured (see results table of Figure 5).

Example 3

With reference to Figures 7 and 8, there is described hereinafter a galvanized steel deck 10 in accordance with yet another embodiment of the present invention. The structure and design of the galvanized steel deck 10 in this embodiment is similar to the galvanized steel deck 10 described in Example 1 and similarly comprises the preferred properties mentioned above (see Figure 8). However, in this embodiment, the height of the galvanized steel deck 10 is about 100 mm. The galvanized steel deck 10 is similarly subjected to a preliminary load/span testing. During the testing, a theoretical load is applied to a galvanized steel deck 10 of a predetermined steel thickness and a pre-determined slab thickness, and the corresponding span (in mm) is measured (see results table of Figure 7).

Example 4 With reference to Figures 9 and 10, there is described hereinafter a galvanized steel deck 10 in accordance with yet another embodiment of the present invention. The structure and design of the galvanized steel deck 10 in this embodiment is similar to the galvanized steel deck 10 described in Example 1 and similarly comprises the preferred properties mentioned above (see Figure 10). However, in this embodiment, the height of the galvanized steel deck 10 is about 120 mm.

The galvanized steel deck 10 is similarly subjected to a preliminary load/span testing. During the testing, a theoretical load is applied to a galvanized steel deck 10 of a predetermined steel thickness and a pre-determined slab thickness, and the corresponding span (in mm) is measured (see results table of Figure 9). In each of Examples 1 to 4 described above, the load/span testing and results table are based on the following assumptions:

1. The concrete density being about 2400 kg/m .

2. There are end supports across the full width of a panel. The panel comprises the total number of galvanized steel decks 10 that is required to cover a desired open space.

3. The bearing area to be about 70 mm. The bearing or "end bearing" is the end support that sits in the steel beam at both ends of a steel sheet.

4. The construction loads being: a. Point load to be about 100 kg/m . b. Imposed construction load to be about 1.5 KPa (or 4.5/Load for Length>3m).

5. The spans are based on maximum allowable deflection of about Load/250.

6. The cantilevered portion of a composite slab to be less than 5 x H, where H = height of slab thickness.

In accordance with another aspect of the present invention, there is described hereinafter a galvanized steel decking system 30 for use in the construction of buildings such as steel frame buildings, concrete frame building and similar building types.

The system comprises a plurality of galvanized steel decks 10 connected to one another. Each of the galvanized steel deck 10 comprises an elongate member having a first portion shaped for receiving a female connector 13 and a second portion shaped for receiving a male connector 12. The first portion comprises a male connector 12 and the second portion comprises a female connector 13, in which the male and female connectors are releasably connectable to corresponding connectors on an adjacent steel deck 10 thereby enabling a plurality of steel decks to be connected to one another to form a galvanized steel decking system 30. When a female connector 13 of one galvanized steel deck 10 is connected to a corresponding male connector 12 of an adjacent galvanized steel deck 10, they are positively interlocked, hence advantageously preventing the connected galvanized steel decks 10 from moving apart during the construction stage where wet concrete is poured over the galvanized steel decks 10. Each of Figures 4B, 6B, 8B and 10B shows a galvanized steel decking system 30 in accordance with an embodiment of the present invention. Advantageously, the present invention possesses a positive interlocking system which advantageously prevents galvanized steel decks 10 from moving apart during the construction stage where wet concrete is poured over the galvanized steel decks 10. The present invention also provides an improved bonding between a galvanized steel deck 10 and concrete which results in improved compose performance, improved spanning ability and improved fire resistance properties.

It is to be understood that the above embodiments have been provided only by way of exemplification of this invention, and that further modifications and improvements thereto, as would be apparent to persons skilled in the relevant art, are deemed to fall within the broad scope and ambit of the present invention described herein. It is further to be understood that features from one or more of the described embodiments may be combined to form further embodiments.