Background of the Invention In situ construction methods of reinforced concrete buildings are well known. In many technologically advanced countries the method has been overtaken by the use of pre- fabricated modular building construction, steel framed structures and so called industrialized building. Nevertheless, in situ or on-site construction methods are still extensively used, particularly in those countries where labour is relatively cheap and/or load bearing steel framing for buildings is relatively expensive.

The most common method of in situ construction of reinforced concrete buildings known to the applicant, consists of the sequential steps of preparing formwork and casting the foundation, preparing formwork and casting the load bearing floor beams together with the floor slab, preparing formwork and casting the ground floor support pillars, preparing formwork and casting the upper floor beams together with the upper floor slab and finally forming the walls by in-filing between the beams and pillars with a wall panel, brick, doors, windows or the like, as desired. The sequence of building is repeated during the construction of additional floors.

Summary of the Invention One object of the present invention is to provide a useful alternative to the above well known method. Another object is to improve existing methods by making more efficient use of labour and materials during the in situ construction of concrete buildings.

In accordance with one aspect of the invention there is provided a method of in-situ construction of a reinforced concrete building including, first temporarily supporting pre-

formed wall members in desired positions on building support means, and then casting the building vertical support pillars utilising suitable surfaces of the wall members as formwork for the pillars.

The wall members preferably include a lower horizontal load bearing reinforced concrete support beam adapted to form at least a part of a load bearing horizontal support beam for the concrete building. Reinforcement means extends from the ends of the beam ready for interconnection with the building support pillars during the casting of the pillars.

During the casting of the floor slabs, suitable surfaces of the wall members may be utilised as part of the slab formwork when casting the floor slab (s).

In floor plans where a pillar is located at the intersection of a plurality of wall members, then suitable surfaces of each wall member can be utilised as formwork when casting the pillar (s).

In accordance with another aspect of the invention, there is provided a method of in-situ construction of a reinforced concrete building including the steps of, first positioning and temporarily supporting pre-formed concrete frame wall members on building support means, said wall members including upper and lower horizontal frame members and vertical frame members located adjacent each end of the horizontal members, said lower horizontal frame member being in the form of a load bearing reinforced concrete support beam adapted to form at least a part of a load bearing horizontal support beam for the reinforced concrete building, casting the building support pillars utilising suitable surfaces of the wall member as part of the formwork for the pillar, and casting the floor slab, utilising suitable surfaces of the wall member as part of the formwork for the building floor slab.

When it is desired to build multi-storey buildings then the invention includes the additional steps of, positioning and temporarily supporting pre-formed upper wall members on the lower wall members, casting the building support upper pillars utilising suitable surfaces of the upper wall members as part of the formwork for at least one pillar, and casting the upper floor and roof slabs, utilising suitable surfaces of the wall members as part of the formwork for the slabs.

In accordance with another aspect of the invention, there is provided a concrete wall member for use in the in situ construction of a reinforced concrete building having load bearing horizontal support beams, said wall member including upper and lower horizontal frame members and vertical frame members located adjacent each end of the horizontal members, said lower horizontal frame member being in the form of a load bearing reinforced concrete support beam adapted to form at least a part of the load bearing horizontal support beam for the reinforced concrete building.

The wall members may be pre-formed in any suitable location. For example, they could be pre-formed remote from the building site and transported thereto.

A variety of different wall members may be provided. For example, the wall panels may be suitably in-filled and finished with, a hollow concrete panel, and/or bricks, cement, doors, widows or the like.

Brief Description of the Drawings Figure 1 to 8 illustrate the steps in the prior art method of in-situ concrete building construction.

Figure 9 is a front view of a pre-formed wall member constructed in accordance with this invention.

Figure 10 to 14 illustrate the steps in a method of in-situ concrete building construction, the method being in accordance with this invention.

Figure 15 to 18 are plan views of the intersection of the wall members with the vertical support pillars, constructed in accordance with this invention.

Figure 19 to 21 illustrate the steps in the construction of the wall panel of Figure 9.

Figure 22 is an enlarged cross-sectional view along axis AA of the wall panel of Figure 20.

Detailed Description of the Preferred Embodiment Figure 1 to 8 illustrate the prior art method of the in situ construction of a simple single room per floor, two storey reinforced concrete building.

Referring first to Figure 1, building support means in the form of footings (2) are cast in position. Next, as illustrated in Figure 2, suitable formwork is prepared and reinforced concrete floor beams (4) are cast together with a floor slab (6). Referring now to Figure 3, suitable formwork is prepared and the ground floor pillars (8) are cast in situ. Next, suitable fonnwork is prepared and the upper floor beams (10) as shown in figure 4 are cast in situ together with the upper floor slab. The lower wall (14), see figure 5, is then constructed, for example by in-filing with bricks and finishing with plaster. Next, the upper floor is commenced by preparing suitable formwork and casting the upper floor pillars (16) as seen in figure 6. Next, referring to figure 7, suitable formwork is prepared and the roof beam (18) is cast in place together with roof slab. Finally, referring to figure 8, the upper wall (22) is constructed with suitable in-filing. The relatively large amount of formwork is removed at convenient stages.

Figure 9 to 22 refer to the preferred example of the present invention when constructing a simple one room per floor, two storey reinforced concrete building.

Referring first to figure 9, a wall member (24) is constructed adjacent the building site or it may be constructed remote from the site and transported thereto. The wall member includes upper (26) and lower (28) horizontal frame members and side vertical frame members (30, 32) located adjacent each end of the horizontal members. The lower horizontal frame member (28) is in the form of a load bearing reinforced concrete support beam adapted to form the load bearing horizontal support beam for the reinforced concrete building. Metal reinforcement (33) is shown extending from the load bearing beam ends for interconnection with the support pillars during casting of the pillars. Being the first floor of the building, the upper beam (26) is relatively not load bearing so that a reinforcement extension is not necessary. The wall member is suitably in-filled and finished with, a hollow concrete panel, and/or bricks, cement, doors, widows or the like.

The building is commenced by completing building supports in the form of footings (34) as seen in figure 10. Next, as seen in figure 11, the pre-formed four wall members (24) are temporarily supported in position in accordance with the floor plan. Reinforced concrete ground floor pillars (36) are then cast in situ as seen in figure 12. As seen in figure 15, vertical end faces (38) of the walls are utilised as part of the formwork when casting the pillars (36). Next, the floor slab is cast, utilising the inner surfaces of the lower wall beams (28) as formwork for the slab. The sequence is continued during the construction of the upper floor by first temporarily supporting the pre-formed upper wall members (40) in position, as seen in figure 13. The pre-formed walls include reinforced concrete roof beams (41). The roof beams being load bearing are thus provided with metal reinforcement (43) extending from the beam ends for interconnection with the pillars during casting of the pillars. As seen in figure 14, the upper floor pillars (42) are then cast in-situ utilising end faces of the walls as formwork when casting the pillars. Finally, the upper floor and roof slabs are cast utilising the suitable surfaces of the wall members as formwork for the slabs.

Figure 15 to 18 illustrate in plan view how the surfaces of differently connected pre-formed walls may be used as formwork for casting the pillars. Figure 15 shows the connection of two walls at a corner of the building, wherein two wall edges (38) are utilized as a part of the pillar formwork. Figure 16 shows a two wall co-planar connection, wherein two wall edges (46) are utilized as a part of the pillar formwork. Figure 17 shows the interconnection of three pre-formed walls, wherein three wall edges (48) are utilized as a part of the pillar formwork.

Finally, figure 18 shows the interconnection of four pre-formed walls, wherein four wall edges (50) are utilized as a part of the pillar formwork.

Figure 19 to 22 illustrate the construction of one type of wall member having a hollow wall interior. As seen in figure 21 a wall member (52) is constructed off-site and includes upper (26) and lower (28) horizontal frame members and side vertical frame members (30,32) located adjacent each end of the horizontal members. The lower horizontal frame member (28) is in the form of a load bearing reinforced concrete support beam adapted to form at least a part of the load bearing horizontal support beam for the reinforced concrete building.

Referring to figure 19, the beam (28) and the vertical side members (30,32) are first cast. The hollow panel (54) is then cast as shown in figure 20. To obtain the triangular pattern hollow interior of panel (54) as seen in figure 22, a series of triangular section rods (not shown) are

positioned to extend from the inner face of the lower beam (28) to the height of the side pillars. Following casting of the in-fill area (54) shown in figure 20 the rods are removed.

Finally as seen in figure 21 the top beam (26) is cast in position.

One advantage of the invention over the prior art is that it is not necessary to cast the building horizontal support beams in situ because they are already pre-formed as part of the pre- formed wall. This can result in relatively large savings in the total time taken to complete the in-situ construction of the building.

Another advantage is that the pre-formed wall surfaces can form major parts of the formwork necessary to construct the floor slabs and the pillars. This can result in a reduction in the time required to prepare the formwork and a reduction in materials required for the formwork.

Yet another advantage is that the wall member can be in-filled with windows, doors, bricks, cement or the like off site. This also can result in relatively large savings in the total time taken to complete the in-situ construction of the building.

Although the invention has been described with reference to a simple two storey, single room per floor building, of course the invention may be readily adapted to build both single or multiple storey buildings. Similarly, the floor (s) of the building may be provided with various layouts of single or multiple rooms on each floor.

Of course, obvious modifications to the above preferred example will occur to those skilled in the art. It is to be understood that such modifications are intended to fall within the scope of the invention, which is defined by the following claims.