FIELD OF INVENTION The present invention relates to the field of panels used in the construction industry.

BACKGROUND Construction technology constantly evolves, and an area of technology which has been increasingly adopted for construction of buildings relates to prefabricated prefinished volumetric construction (PPVC). With the use of PPVC construction processes, buildings are constructed at a faster pace, with fewer workers required on-site. Furthermore, quality of construction can also be better controlled, as the PPVC construction structures can be constructed in a remote location where quality control processes are in place, resulting in buildings with a more consistent level of quality,

However, PPVC structures typically require use of concrete when assembling the PPVC structures. There is a requirement for pouring, setting and curing of the concrete, which requires substantial time as well as the application of appropriate processes to ensure that the concrete is used in a desired manner. If the concrete is not applied in the desired manner, the quality/safety of the building becomes compromised, which is undesirable.

In addition, the use of concrete requires the concrete to be beyond a minimum thickness so as to have desired strength and fire retardation properties. Unfortunately, this leads to a situation whereby heights of individual PPVC structures are adversely affected. This substantially affects an appearance of the buildings constructed using PPVC processes. Therefore, it is evident that there are shortfalls in relation to PPVC processes which are currently in use for construction projects.

SUMMARY

There is provided a panel system comprising:

a loadbearing portion comprising:

a non-combustible structural cementitious layer;

at least one insulation layer adjacent to the non-combustible cementitious structural layer;

a plurality of fibrous insulation layers adjacent to the at least one insulation layer;

a first plurality of metal joists for securing the aforementioned layers of the loadbearing portion; and

a metal base grid plate; and

a fire-compartmental portion adjacent to the loadbearing portion comprising:

a metal top plate;

at least two fire-retardant plasterboard layers; and

a second plurality of metal joists for attaching the aforementioned layers of the fire-compartmental portion.

Preferably, the loadbearing portion is configured to provide structural rigidity for the panel system. It is preferable that the non-combustible cementitious structural layer comprises gypsum and cement.

It is preferable that the fire-compartmental portion is configured to prevent fire from causing failure of the panel system before a pre-determined period of time.

Preferably, the at least one insulation layer is made from mineral fiber wool, and the metal base grid plate/the metal top plate is made from steel. The steel plate is preferably between 1 mm and 1 .2mm thick, and has a density of between 7750 kg/m ³ and 8050 kg/m ³ .

It is preferable that a perimeter of the at least two fire-retardant plasterboard layers is in contact with a fire-retardant sealant.

The metal top plate portion is preferably configured to provide strength and weather protection, the loadbearing portion is preferably usable for flooring, and the fire-compartmental portion is preferably usable for ceilings.

Preferably, the loadbearing portion is within a flooring steel beam frame, while the fire-compartmental portion is preferably mounted to a ceiling bracket.

It is advantageous that the panel system is rated for at least two hours of fire resistance.

DESCRIPTION OF FIGURES

Some embodiments of the present invention are hereinafter described, by way of example only, with reference to the accompanying drawings, wherein:

Figure 1 shows an embodiment of a cross sectional view of a panel system;

Figure 2 shows an embodiment of a perspective view of the panel system of Figure 1 ;

Figure 3 shows an example of a PPVC structure; and

Figure 4 shows a graph of temperature vs time of the panel system of Figure 1 during a fire testing session.

DETAILED DESCRIPTION The present invention provides a panel system which can be used in prefabricated prefinished volumetric construction (PPVC) structures. The panel system can comprise a floor structure and a ceiling structure of the PPVC structures, with the ceiling structure being a self load-bearing structure, without any hanger. The panel system provides a completely "dry" application, whereby there is no use of concrete. Thus, there is no need for pouring, setting and curing of the concrete, which saves time and labour involvement/costs. The panel system is installable in a manner which requires less time and labour involvement/costs. Higher productivity is an advantageous consequence. The panel system also results in a thinner floor/ceiling configuration, which enables taller interior spaces.

Referring to Figures 1 and 2, there is provided an embodiment of a panel system 100 comprising a loadbearing portion 102, and a fire-compartmental portion 104. The loadbearing portion 102 conforms with Eurocode 3 and can be usable for flooring for a PPVC structure. The loadbearing portion 102 can also be configured to provide structural rigidity for the panel system 100. The fire-compartmental portion 104 can be usable for ceilings for a PPVC structure. The fire- compartmental portion 104 can be configured to prevent fire from causing failure of the panel system 100 before a pre-determined period of time. Some test findings for an embodiment of the panel system 100 will be provided in a subsequent section.

Referring to Figure 3 for illustrative purposes, the loadbearing portion 102 is shown as a floor of a PPVC structure 99, and the fire-compartmental portion 104 is shown as a ceiling of the PPVC structure 99. Even though the loadbearing portion 102 and the fire-compartmental portion 104 appear to be separate components assembled to the PPVC structure 99, it should be noted that the loadbearing portion 102 and the fire-compartmental portion 104 are adjacent to one another during stacking of a plurality of the PPVC structures 99, whereby each PPVC structure 99 is in a vertical orientation as shown in Figure 3. Thus, the panel system 100 of Figures 1 and 2 is formed once the plurality of the PPVC structures are stacked.

The loadbearing portion 102 can be part of a flooring steel beam frame 106. The loadbearing portion 102 comprises a non-combustible cementitious structural layer 108. The cementitious structural layer 108 can be, for example, a panel that includes both gypsum and cement. The loadbearing portion 102 also includes at least one insulation layer 1 12 adjacent to the non-combustible cementitious structural layer 108. The at least one insulation layer 1 12 can be in contact with the non-combustible cementitious structural layer 108, or a gap can be left between the at least one insulation layer 1 12 and the non-combustible cementitious structural layer 108. The at least one insulation layer 1 12 can be configured to provide sound and temperature insulation and is made from, for example, mineral fiber wool, stone wool (for example, Rockwool™ ThermalRock S60) and so forth.

In addition, the loadbearing portion 102 also includes a plurality of fibrous insulation layers 1 10 adjacent to the at least one insulation layer 1 12. For example, a fibrous insulation layer can be made from 50mm rock wool with density of 60 kg/m ³ . The loadbearing portion 102 also includes a first plurality of metal joists 1 14 for securing the aforementioned layers 108, 1 10, 1 12 of the loadbearing portion 102. The first plurality of metal joists 1 14 can be made from steel and can be in a form of, for example, a channel of dimensions 125mm x 65mm. The plurality of metal joists 1 14 distributed within the loadbearing portion 102 provides structural strength to the loadbearing portion 102.

The loadbearing portion 102 also includes a metal base plate 1 1 1 which is mounted to the flooring steel beam frame 106. In some instances, the metal base grid plate 1 1 1 is made from steel, and is similar in form to "chicken wire netting" or "chicken mesh". The metal base grid plate 1 1 1 can be between 1 mm and 1 .2mm thick, and can have a density of between 7750 kg/m ³ and 8050 kg/m ³ . Steel brackets 107 are included within the flooring steel beam frame 106 for mounting the aforementioned layers 108, 1 10, 1 12 of the loadbearing portion 102.

The fire-compartmental portion 104 is incorporated within a ceiling frame 126 and the ceiling frame 126 is mounted to a ceiling bracket 1 18. The fire-compartmental portion 104 comprises a metal top plate 122, which can be made from steel. The steel plate can be between 1 mm and 1 .2mm thick, and can have a density of between 7750 kg/m ³ and 8050 kg/m ³ . The metal top plate 122 provides cover for the ceiling frame 126 and correspondingly, also provides weather protection and strength for the ceiling frame 126.

The fire-compartmental portion 104 also includes at least two fire-retardant plasterboard layers 120. Each fire-retardant plasterboard layer 120 can be, for example, a 16mm Firestop™ board manufactured by USG Boral™. The fire- compartmental portion 104 also includes a second plurality of metal joists 124 for attaching the aforementioned layers of the fire-compartmental portion 104.

When the fire-compartmental portion 104 is mounted to the ceiling bracket 1 18, a perimeter of the at least one fire-retardant plasterboard layer 120 is in contact with a fire-retardant sealant 1 16. The fire-retardant sealant 1 16 can be, for example, Firecault™ sealant from USG Boral™.

Referring to Figure 4, there is shown a graph of temperature vs time of the panel system 100 of Figure 1 during a fire testing session. The fire testing session is in accordance with BS 476: Part 21 : 1987, Clause 7 on a double deck load-bearing insulated flooring system and a non-load-bearing ceiling system. It can be seen from the graph that the maximum elevation of temperature of the panel system 100 is less than 180°C, after nearly 140 minutes of the fire testing session. In relation to fire testing, once 180°C is breached by a construction system undergoing the test, the thermal insulation criteria is reached and the fire test ceases. This indicates that under the defined conditions of the fire testing session, the panel system 100 is able to demonstrate at least two hours of fire resistance.

With the present invention, there is provided a panel system which can be used in PPVC construction and is able to demonstrate at least two hours of fire resistance. The panel system is particularly useful for PPVC construction as the stacking of PPVC structures consequently aids in forming the panel system and the associated benefits. As described in the preceding paragraphs, the panel system provides a completely "dry" application, whereby there is no need for concrete. Thus, there is no necessity for pouring, setting and curing of the concrete, which saves time and labour involvement/costs. This panel system allows PPVC construction to be carried out in a manner which requires less time and labour involvement/costs. Higher productivity is an advantageous consequence. The panel system also results in a thinner floor/ceiling configuration, which enables taller interior spaces and enhanced interior aesthetics.

Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention.