GB2373003A

GB2373003A - Precast panel building system

Info

Publication number: GB2373003A
Application number: GB0107415A
Authority: GB
Inventors: John Joseph Owens; Hugh Norbert Henry
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-09
Filing date: 2001-03-22
Publication date: 2002-09-11
Anticipated expiration: 2021-03-22
Also published as: IE20020171A1; IES20010233A2; GB2373003B; GB0107415D0

Abstract

A cavity wall assembly (1) comprises two parallel opposed leaves (15,16) defining a cavity which contains an insulation layer (31). The opposed leaves comprise precast concrete panels each having at least one, but preferably two, sockets (36) formed therein. There is provided at least one bracket (e.g. 35) for connecting the opposed panels. The bracket, which may be u-shaped, has a first part which bridges the cavity and has two downwardly depending fastening members e.g. dowels, extending substantially perpendicular to the bridging part, one fastening member being received in one socket of one panel and the other fastening member being received in a corresponding socket in the opposed panel, whereby the panels are secured in position. The fastening members may be secured into the sockets by the use of grout. The brackets may have laterally extending straps (41) for fastening to a floor slab.

Description

A Building System

Field of the Invention The invention relates to a building system comprising precast panels and connecting means for joining the panels together in the construction of a building. The invention also concerns a method of building and a building constructed by the method.

Background Art It is known to use precast panels for the modular construction of houses and other buildings. Such systems have advantages in that they improve speed of construction and reduce building costs.

For example, US 5,230, 191 (Mayrand) discloses a precast insulated concrete panel and method of forming same and a building structure incorporating such panel. The precast insulated concrete panel is comprised of an outer insulating skin formed by a rigid layer of insulating sheet foam material connected to a concrete inner wall layer cast on the inner surface of the insulating material. The inner surface of the insulating material has connecting cavities formed therein so that the concrete flows into the cavity and connects to the rigid insulating material through integral plugs of concrete which are set formed with the connecting cavities. Connectors are also formed in the concrete and the insulation to connect and manipulate the panels and to attach outer finishing building materials to the insulation.

These panels may be utilized in a tilt-up construction method and connect to floor slabs to form building structures of more than one storey. The system described uses a single leaf insulated panel construction.

Many of the known modular building systems utilising precast panels have single leaf walls which simplifies the connections between the elements.

It is known to use precast panels in the construction of a wall having an inner leaf and an outer leaf defining a cavity. For example. US 5,802, 793 (De Vore, Jr. ) discloses a wall

system utilizing a plurality of precast concrete panels so that a parallel inside wall and outside wall is created. Each panel of the plurality has a continuous slot on all four perimeter sides that mutually oppose slots on adjacent panels. A strip fits into the slot formed by the two abutting panels, thus aligning, reinforcing, and sealing the plurality. The outside wall is connected to the inside wall by one or more embedded protrusions from the opposite panels so that the protrusions overlap upon each other. The overlap is then fastened together by a chosen method, for example a cast-in bolt and nut or spot welding areas of mesh intersection providing a bridge between the opposite panels. The panels are relatively small modular units.

Object of the Invention It is an object of the invention to provide a simplified system and method for the modular construction of buildings using precast panels to form cavity walls and floors, and to provide a simplified and rigid connecting system for the panels.

Summary of the Invention In accordance with one aspect the invention provides an assembly for constructing a building wall structure having two parallel laterally spaced opposed leaves which define a cavity which is intended to contain an insulation layer, the assembly comprising two precast concrete panels which define the leaves, and each of which panels is generally planar having a pair of opposed planar surfaces joined by top, bottom, and end edge faces; each of the panels has at least one socket formed in the panel; and at least one connecting bracket for connecting the opposed panels, the bracket comprising a bridging part which bridges the cavity and has two downwardly depending fastening members, extending substantially

perpendicular to the bridging part, one fastening member being received in one socket of one t : zn panel and the other fastening member being received in a corresponding socket in the opposed panel, whereby the panels are tied together. Preferably each of the panels has at least two sockets formed in a top edge face of the panel, and the sockets are spaced apart along the length of the panel, and there are at least two connecting brackets.

Suitably, the bracket is substantially u-shaped. It many comprise two downwardly extending dowels (as hereinafter defined) connected by a bridging part which may be in the form of a plate. Alternatively, the bracket may comprise a bridging plate and the dowels comprise bolts which extend through holes in the plate. The u-shaped bracket could also be formed by bending a steel rod to a substantially u-shape.

Preferably, the wall structure has a lower wall level comprising two laterally spaced wall panels, and an upper wall level comprising two laterally spaced wall panels resting substantially vertically on the lower wall panels, and wherein the panels are interconnected by means of at least two connecting brackets, each bracket comprising a bridging part which is positioned between the upper and lower wall panels and which bridges the wall cavity, and, adjacent each end of the bridging part, there are opposed substantially vertically extending fastening members, e. g. dowels, the downwardly depending fastening members fitting within the sockets formed in the top part, e. g. the top edge faces of the lower level panels, and the upstanding fastening members fitting within corresponding sockets formed in the bottom part, e. g. the bottom edge faces of the upper level panels.

The laterally opposed panels forming the upper wall level are interconnected at the tops, e. g. the edge faces, thereof by means of connecting brackets, as described above.

Suitably, the precast wall panels are connected substantially perpendicularly to each other to define a corner, with the end edge faces of two laterally spaced panels abutting the planar surfaces of two perpendicularly adjoining laterally spaced panels, and the adjoining panels are connected together by connection means, each of which means comprise a bolt which passes through a bolt-retaining plate held in a recessed opening through the opposed planar surfaces of one panel, adjacent an end thereof, and the bolt is engagable with an insert

in the abutting end edge face of the perpendicularly adjoining panel.

F-7 In accordance with another aspect, the invention provides a building comprising a front wall, a rear wall, and two side walls, wherein at least the front and rear walls are cavity wall structures as defined above, and wherein at ground level the laterally opposed precast concrete wall slab forming the wall leaves rest upon rising walls or other foundation

structures, and the building includes a floor slab which forms the ground floor of the building and which is connected to the laterally spaced wall panels, forming at least the front and rear walls of the building, by connecting brackets which also connect the laterally spaced wall panels, each of the connecting brackets comprising a bridging part, e. g. a plate, which bridges the cavity between the spaced wall panels and has a pair of spaced upstanding dowels, one of which is received in a socket in the lower end face of one panel, and the other of which is received in a corresponding socket in the lower end face of the opposed panel, and the bracket has a strap portion which extends laterally therefrom and which is fastened to the floor slab.

Suitably, the building has a ground floor level, and a first floor level, the front and rear walls of which are comprised of wall structures as defined above, and the building includes a first floor slab structure which is connected to the laterally spaced wall panels by connecting brackets which also interconnect the laterally spaced wall panels of the upper and lower wall levels, the bracket comprising a bridging part, e. g. a plate, which bridges the cavity between the laterally spaced wall panels at the joint between the upper wall level and the lower wall level, and adjacent each end of the bridging part there are opposed substantially vertically extending dowels, the downwardly depending dowels fitting within the sockets formed in the top edge faces of the lower level panels, and the upstanding dowels fitting within corresponding sockets formed in the bottom edge faces of the upper level panels, and each bracket has a strap portion which extends laterally therefrom and is fastened to the upper floor slab.

The opposite edges of the floor slab structure abut the inner leaf of each opposite wall of the building and is connected thereto by the connecting brackets, and wherein at least one of the remaining opposite edges of the floor slab structure is supported on the upper end face of the inner leaf of the adjoining lower level wall.

The front and wall structures are connected at ends thereof to a party wall which separates the building from an adjoining building having similar wall structures, and the inner ends of the inner leaves of the adjoining wall structures of each building overlap the end edge face of the party wall and are connected thereto by bolts which pass through a bolt

retaining plate held in recesses in the ends of the wall panels, and the bolts are engagable with inserts in the end edge face of the party wall, and the inner and outer leaves of the wall structure are interconnected by connecting brackets.

The sockets formed on the lower edge faces of the panels are of such dimensions that the dowels fit loosely within the sockets, and the sockets have access ports opening to the panel surface to enable grout, or similar fixing material, to be injected into the sockets.

The term"dowel"as used in the description and claims is intended to embrace any suitable elongate member, such as a pin, bolt, plate or the like, which is suitable for retention within a complementary socket.

Brief Description of the Drawing One embodiment of the invention is hereinafter described with reference to the accompanying drawings, wherein Figure 1 is an isometric view of the front and side walls of a building showing the wall structure of the invention; Figure 2 is a front elevation of a precast front wall panel of the invention forming the outer leaf of the wall; Figure 2A is a front elevation of the wall panel forming the inner leaf of the front wall; Figure 3 is a part-plan view of the assembled panels of Figures 1 and 2; Figure 4 is a cross-section of a building construction of the invention on the line V-V of Figure 5; Figure 5 is a ground floor plan of the building construction of Figure 4; Figure 6 is a first floor plan of the building construction of Figure 4; Figure 7 is a sectional view to an enlarged scale of the building construction at ground floor and foundation level showing the connection A of Figure 4; Figure 8 is a comer detail, to an enlarged scale, of the corner joint B of Figure 5; Figure 9 is an isometric view, to an enlarged scale, showing a detail at first floor level of the connection C of Figure 4;

Figure 10 is an isometric view, to a smaller scale, of a connecting strap of the invention ; Figure 11 is a sectional view of the detail of Figure 9 ; Figure 12 is a plan view, to an enlarged scale, at first floor level of the connection D of Figure 6; Figure 13 is a sectional elevation, to an enlarged scale, of a wall/floor joint at E of Figure 1; Figure 14 is an isometric cutaway view of the wall/floor joint of Figure 13; Figure 15 is an isometric view of a wall connector of the invention; Figure 16 is a sectional elevation, to an enlarged scale, of a detail of the wall at roof level at F of Figure 4; Figure 17 is an isometric view of the detail of Figure 16; and Figure 18 is an isometric view of a wall connector of the invention.

Referring to the drawings, Figure 2 shows a precast concrete front wall panel 1 which is intended to form the outer leaf of a front cavity wall of the building construction of Figure 1. Figure 2A is a similar view of a precast concrete wall panel 2 which forms the inner leaf of the cavity wall. Thus, the panel of Figure 2A is narrower in width than that of Figure 2.

The panels 1 and 2 have pre-formed door openings 3 and window openings 4. Figure 3 shows the panels 1,2 in an erected form to define a cavity 5 therebetween. Also shown in Figure 3 are parts of side wall panels 6,7 partition wall 18 and party wall 9.

Referring now to Figures 1 and 4 these are an isometric and cross-section, respectively, of a house constructed by means of the wall structure of the invention. The house comprises foundations 10 upon which are built rising side walls 11,12, and a central rising wall 13, all built in well known manner. A ground floor slab 14, preferably cast in situ on a suitable hard core base extends between the rising walls 11,12, 13 and the walls are connected to the floor slab as described below.

Precast front wall panels 1,2 (see Figs. 1 to 3) are erected on the rising walls 11,12 and form the front of the building. The wall panels 1,2 extend to first-floor level. Similarly, rear pre-cast wall panels 20,21 form the rear wall of the building to first floor level (Fig. 4).

A partition wall 8 is erected on the central rising wall 13. A second pair of wall panels 15, 16 is mounted on the lower front wall panels 1,2, respectively and form the upper front

facade of the building, while rear wall panels 22, 23, resting on walls panels 20, 21, form the rear upper facade of the building. A plurality of precast slabs 19 form the first floor of the building and are connected to the wall panels as described in more detail with reference to Figure 9 below. The upper wall panels 15,16 and 22,23 support a standard roof truss 17, as described in more detail below with reference to Figures 16 and 17.

Figure 5 is a ground floor plan of the building showing the front walls 1,2 forming the front of the building, the rear wall panels 20,21 forming the rear cavity wall of the building and side wall panels 6,7 forming a side cavity wall of the building. The building is substantially rectangular in plan, and the remaining wall 9 is a party wall separating the building from an adjoining building which is constructed in a similar manner. The building has internal partition walls 8,18, in well known manner.

Figure 6 is a plan view similar to Figure 5 but at the first floor level. This shows the upper first floor wall panels 22,23 which are resting on the lower panels 20,21 ; the upper front wall panels 15,16 resting on lower panels 1,2 and upper side wall panels 24,25 which rest on lower side wall panels 6,7 (se also Fig. 1).

Referring now to Figure 7, this shows the connection between the ground floor slab 14 and the wall panels 20,21 at the location A of Figure 4. Rising walls 11,12 are built in conventional manner from block, on a foundation 10. The rising walls 11,12 rise above the ground level 30. The precast rear wall panels 20,21 rest upon, and extend vertically from, the rising walls 11,12 respectively. A damp proof course (not shown) is inserted between the bottoms of the panels 20,21 and the top of the rising walls 11,12. The precast panels 20, 21 are spaced apart to define a cavity 5 which contains a sheet of insulation 31 in well known manner. A ground floor slab 14 extends horizontally and its end face abuts the inner rising wall 12 at a position such that the top surface of the slab 14 is substantially co-planar with the top of the rising wall 12. The ground floor slab 14 is cast in-situ on a suitable hardcore base contained between the rising walls 12. An insulation layer 32 is attached to the lower surface of the floor slab 14.

A connector, similar to that shown in Figure 10 (but without the downwardly extending dowels) is used to connect the floor slab to the two rear wall panels 20, 21. As shown in Fig. 1, a similar connector is used to tie the front panels 1,2 to the floor slab, and also the side wall panels. The connector 40 comprises an elongate bridging strap or bracket 41, which is attached to the top surface of the floor slab 14 by bolts or pins (not shown) inserted through holes 42 in the strap 41 and into the top face of the slab 14. The bridging strap 41 extends across the top of the rising wall 11, bridges the cavity 5, and extends across the top of the rising wall 11. The connector 40 has two upstanding dowels 43,44, which extend substantially vertically of the strap 41 when it is in the position as shown in Figure 7.

The dowels 43,44 fit within sockets 48,49 formed in the lower ends of the precast panels 20,21. The sockets 48,49 extend in a plane which is substantially parallel to the plane of the front and rear faces of the panels 20,21.

In the construction of the building the foundations 10 are first laid, the rising walls 11,12 are then built, the floor slab 14 is laid horizontally by casting in-situ in concrete. The strap 41 is then fixed in position on the top surface of the floor slab. The strap bridges the standing walls 11,12 and the dowels extend vertically upwardly. The inner wall slab 21 is then lowered by a crane onto the rising wall 12 such that the dowel 44 fits within the socket 49. Likewise, the outer wall slab 20 is lowered onto the rising wall 11 with the dowel 43 fitting within the socket 48. Grout 50 is pumped into the sockets 48,49 through a grout access opening 51. The grout hardens about the dowels 48,49 to form a rigid connection between the floor slab 14 and the wall panel 20,21. A screed layer 52, about 50 mm in thickness, is laid over the upper surface of the floor slab 14, and also over the strap 41. A vertical insulation 53 is positioned between the end of the floor slab and the inner wall leaf.

As shown in Figures 7 and 10 the connector 40 has a bridging piece 47 located between the dowels 43,44, the purpose of which is to cause any condensation forming on the connector 40 to drip within the cavity 5.

Similar connections are made to tie-in the other wall panels to the floor slab 14 so as to stabilise the walls.

Referring to Figure 8, this shows the detail of the corner B of Figure 5 in which the front wall panels 1, 2 abut, at right angles with the side panels 6, 7. Each of the wall panels 1,2 which are intended to abut at right angles to an end face of adjoining panels 6,7 are formed with an stainless steel threaded insert 60. The stainless steel insert 60 is cast into the end edge face of the panel and extends, in a plane parallel to the plane of the face of the panel for a short distance. Although not shown in the drawings, it is tied into reinforcing steel in the panel structure by suitable steel linkage.

The adjoining panels 6,7 are each formed with an opening or slot 61 formed during the moulding of the panel. The opening 61 has a recess 62 to receive a steel fixing plate 63.

When inserted in the recess 62, the plate 63 abuts a rabbet 64. In its inserted position the front of-the plate 63 is substantially flush with the face of the panel 6. The fixing plate 63 has a round hole 65 through which a stainless steel bolt 66 may be inserted. The bolt passes through the opening 61 and is threadedly engaged in the insert 60. When the bolt 66 is tightened it serves to secure end face of the panel 1 at right angles to the end of the panel 6.

In a similar manner, the panels 2,7 forming the inner leaves are likewise connected.

The connection assembly comprising the bolt 66, plate 63, opening 61 and insert 60 are positioned at predetermined intervals on the vertical edge faces of the panels, the number depending upon the height of the panels (see also Fig. 1) The joint shown in Figure 8 is that indicated by B in Figure 5, and is the front corner of the building. At the opposite rear corner the side wall panels 6,7 are connected to the rear wall panels 20,21 in a similar fashion. However, in that connection it is the panels 6,7 which contain the steel inserts in their end faces. Thus, each precast wall panel is provided with inserts 60 at one end face, and with openings 61 at the opposite end face.

The first floor of the building is made up of a plurality of floor slabs 19 which are laid side by side and extend between the side walls of the building, running parallel to the front and rear walls. The connection between the first floor slabs 19 and the side walls, for example at the position C of Figure 4, is illustrated in Figure 9. It will be noticed from

Figure 4 that at the two opposite front and rear walls of the house, the side faces of the floor slabs 19 abut the inner faces of the wall panel leaves 23, 16, respectively. However, at the side walls of the house, the ends of the floor slabs 19, at one end, rest on the top of the wall panel forming the lower inner leave, 7 as shown in more detail in Figure 13. At the opposite end the floor slabs rest on the party wall 9.

Referring now to Figures 9 and 11, the side end face 29 abuts the inner face of the top of the wall panel 21 forming the inner leaf of the wall. In the construction of the building, the connector 40 is then fixed in place. The strap 41 is fixed to the top surface of the floor panel 19, as described previously in relation to Figure 7. However, in this connection arrangement, the connector 40 has two depending dowels, 45,46 aligned with the upstanding dowels 43,44. In fact, in the construction shown the dowels 43,45 and 44,46 are formed by inserting a single pin through the strap 41 to form the dowels. The depending dowels 45,46 fit within sockets 55,56 formed in the top end faces of the wall slabs 20,21. The dowels 45, 46 form a tight fit within the sockets 55,56. The upper wall panels 22,23 are then lowered in position. The upstanding dowels 43,44 fit within sockets 57,58 formed in the lower end faces of the wall panels 22,23. The sockets 57,58 are wider than the sockets 55,56 to allow sufficient play when the top wall panels are lowered. Openings 59 in the face of the wall panels 22,23 give access to the sockets 57,58 to enable grout to be pumped within the sockets to secure the dowels 43,44. A bitumastic impregnated foam strip 67 is placed between all abutting faces of wall panels 22,20 and 23,21, respectively. A screed layer 52 is then laid over the floor panels 19 and the strap 41. As shown in Figure 9, the elongate abutting side faces of the floor slabs 19 are formed with a channel 54. When the floor slabs 19 are laid alongside each other the adjoining channels 54 form an elongate key recess which receives a grout filling. When the grout hardens it keys the floor slabs together (see Fig. 14).

A similar connection arrangement, as described above, is used at spaced intervals to

connect the abutting ends of the floor slabs 19 to the wall slabs and at the same time to c connect the upper and lower wall slabs together, and to secure the inner and outer wall slabs together.

Figures 9 and 11 show the connection of the first floor slab 19 to the rear wall of the building. A similar connection is made to the front wall, as shown in Figure 1.

Figures 13 to 15 show how the ends of the first floor slabs 19 are connected to the walls at the side of the building. At this location, an end of each of the floor slabs 19 rests on the top of the wall panel 7 forming the inner leaf of the side wall. Before the floor slab 19 is laid on the top of the inner leaf, the connecting bracket 70, shown in Figure 15 is put in position. The connecting bracket 70 is shown in more detail in Figure 15, and comprises a flat plate 71 having a dowel 72 extending upwardly at right angles, at one end thereof, and two depending dowels 73 extending downwardly, at right angles, at each opposite end. The plate 71 fits into recesses 74 in the top end faces of the panels 6,7. The two depending dowels 73 form a tight fit within the respective sockets 56 at the top end faces of the wall panels 6,7. The plate 71 bridges the cavity 5 between the walls 6 and 7 and the opposite end of the plate 71 rests within the recess 74 of the wall 6 with the dowel 72 extending vertically upwardly. The upper wall panel 24 is lowered in position such that the upstanding dowel 72 fits within the socket 57 in the lower end face of the upper panel 24, and is grouted in position as hereinbefore described. The inner wall leaf 25 is shorter in height than the outer leaf 24, by a distance equal to the thickness of the floor slab 19. Thus when the inner wall leaf 25 is lowered into position its lower end face rests on the top of the floor slab 19 as shown in Figure 13.

As shown in Figure 14, the floor slabs 19 and the inner wall leaf 25 are interconnected, and tied together, by means of a connecting bracket 80. This comprises an elongate strap 81 to which is fastened the top surface of the floor slab 19 by fasteners inserted through holes 82 The innermost end of the strap 81 is formed with a single upstanding dowel 83 at right angles to the strap 81. When the upper inner leaf 25 is lowered the dowel 83 fits within the socket 58 and is grouted in position by grout inserted through opening 59 as previously described.

When the first floor slabs 19 are secured in position, a screed 52 is laid over the slabs.

Referring now to Figure 12 this is a plan view showing the connection, at first floor level (at location D of Figure 6) between the party wall 9 and the front walls of the two adjoining buildings. As explained in relation to Figures 1 to 3, the front wall of each house is comprised of single panels which span the full width of the building. Thus, the front wall of each adjoining house comprises an outer leaf each comprised of wall panel 1 at ground level, and an inner leaf comprised of wall panel 2. As shown in Figure 12, the outer wall panels 1 of each house abut opposite the centre of the party wall 9. An expansion joint 75, (for example of mastic) is positioned between the abutting end faces of the adjoining wall panels 1. The inner leaves 2 of the front wall of each adjoining house overlap the end of the party wall 9, as shown in Figure 12, but their end faces are spaced apart to define a space 76.

The outer and inner wall leaves 1,2 are connected by a bridging bracket 90 (see Fig.

18) which comprises a flat plate 91 which bridges the cavity 5 between the outer and inner leaves 1,2. The plate 91 has downwardly depending dowels 93,94, one adjacent each end thereof. The plate 91 fits into a recess in the top end faces of the panels 1,2. The depending dowels 93,94 form a tight interference fit within sockets 55,56 in the top end faces of the wall panel 1,2, respectively. The sockets 55,56 are not shown in Figure 12 but are similar to the socket shown in Figure 18.

The ends of the inner leaves 2 are connected to the party wall 9 by means of a connection system which comprises plates 95 which are located, at their ends, in corner recesses 96 moulded into the ends of the leaves 2. Stainless steel bolts 97 are inserted through the plates 95 and are threadedly engaged with threaded sockets 98 secured in the end face of the party wall 9. The threaded sockets are secured by reinforcing bars 89.

The internal partition walls 8 of each adjoining building are secured to the party wall 9 by means of a connecting bracket 85. The connecting bracket 85 comprises a plate 86, which has three spaced apart depending dowels 87,88 and 89, which are disposed at right angles to the plate 86. The dowels form a tight fit within sockets at the top edge faces of the partition walls 8 and a socket centrally disposed in the top edge face of the partition wall 9.

The sockets (not shown in Figure 12) are similar to the sockets 56 of Figure 13.

Details of the roof construction of the building are shown in Figures 16 to 18. At roof level the outer and inner wall leaves 22, 23 are connected by a bridging bracket 90, as shown in Fig. 18 and which has been described above. The downwardly depending dowels 93,94 form a tight interference fit within the sockets 55,56 in the top end faces of the wall panels 22,23. The ends of the plate 91 fit into recesses 99 formed in the top end edges faces of the panels 22, 23. A wall plate 78 is fixed to the top edge face of the panel 23 and a standard roof truss 79 bears on the wall plate 78 in well known manner.

In the embodiments described above the connecting brackets for tying together the outer and inner leaves of the wall structure are, in their basic form, the bracket 70 of Figure 15, or the bracket 90 of Figure 18. Where the bracket is used to tie the wall structure to a floor slab, the bracket has an extending strap part, such as the strap 41 of bracket 40 (Fig.

10). The connecting brackets are provided with downwardly depending dowels, and depending upon the location of use may also be provided with one or more upstanding dowels.

The shape of the connecting brackets may be modified within the scope of the invention, and different possible alternative shapes are illustrated in Figure 1. For example, the bracket 33 is substantially u-shaped and comprises a flat bridging plate bent downwards at each opposite end to form downwardly depending flanges which engage in complementary shaped sockets 34 at the top of each wall leaf. The brackets 35 are also substantially ushaped, and are bent from a length of steel rod, one of which is corrugated on its outer surface. The downwardly depending rod portions engage in cylindrical sockets 36 formed in the top ends of the wall panels. The connecting bracket 37 comprises a flat plate having bolt holes at each end. The ends of the plate fit within recesses 38 formed in the top edge faces of the panels. Bolts 39 are inserted through the holes in the plate and threadedly engage with inserts 69 in the top end faces of the wall panels. The inserts 69 are similar to the inserts 60 described previously, and are secured in a similar fashion. The bracket 90 shown in Figure 1 is similar to that of Figure 18.

In the embodiments illustrated, the sockets which receive the fastening members of the connecting brackets are formed in the top or bottom edge faces of the panels. However,

it will be appreciated that in some cases the sockets may be located on the side face of the panel adjacent the top or bottom end. Thus, for example where the connecting bracket is a u shaped plate, such as the connector 33 shown in Figure 1, the sockets which receive the downwardly extending flanges, which form the fastening members, may be in the form of recesses formed in the faces of the wall panels, adjacent the top and bottom ends. The flanges can be secured in the recesses by grouting or by means of bolts or nails extending perpendicular to the planar surface of the panel.

In general there are two fixing locations on each end of the precast wall panels and two fixings, at least, on the top edge faces. Where the panels are in an upper storey of a building there are also at least two fixings on the bottom edge faces.

From the foregoing, it will be apparent that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It will be appreciated that the present disclosure is intended to set forth exemplifications of the invention which are not intended to limit the invention to the specific embodiments illustrated. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.

The words"comprises/comprising"and the words"having/including"when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims

1. An assembly for constructing a building wall structure having two parallel laterally spaced opposed leaves which define a cavity which is intended to contain an insulation layer, the assembly comprising : c a) two precast concrete panels which define the leaves, and each of which panels is generally planar having a pair of opposed planar surfaces joined by top, bottom, and end edge faces, each of the panels has at least one socket formed in the panel; and b) at least one connecting bracket for connecting the opposed panels, the bracket comprising a bridging part which bridges the cavity and has two downwardly depending fastening members, extending substantially perpendicular to the bridging part, one fastening member being received in one socket of one panel and the other fastening member being received in a corresponding socket in the opposed panel, whereby the panels are secured in position.

2. An assembly as claimed in claim 1, wherein each of the panels has at least two sockets formed in a top edge face of the panel, and the sockets are spaced apart along the length of the panel, and there are at least two connecting brackets.

3. An assembly as claimed in claim 1 or 2, wherein the wall structure has a lower wall level comprising two laterally spaced wall panels, and an upper wall level comprising two laterally spaced wall panels resting substantially vertically on the lower wall panels, and wherein the panels are interconnected by means of at least two connecting brackets, each bracket comprising a bridging part which is positioned between the upper and lower wall panels and which bridges the wall cavity, and, adjacent each end of the plate, there are opposed substantially vertically extending fastening members, e. g. dowels, the downwardly depending fastening members fitting within the sockets formed at the top of the lower level panels, and the upstanding fastening members

- I I I I fitting within corresponding sockets formed at the bottom of the upper level panels.

4. An assembly as claimed in claim 3, wherein the laterally opposed panels forming the upper wall level arc interconnected at the top edge faces thereof by means of

connecting brackets as claimed in claim 1. tn

5. A wall structure as defined in any of the preceding claims, wherein the precast wall panels are connected substantially perpendicularly to each other to define a corner, with the end edge faces of two laterally spaced panels abutting the planar surfaces of two perpendicularly adjoining laterally spaced panels, and the adjoining panels are connected together by connection means, each of which means comprise a bolt which passes through a bolt-retaining plate held in a recessed opening through the opposed planar surfaces of one panel, adjacent an end thereof, and the bolt is engagable with an insert in the abutting end edge face of the perpendicularly adjoining panel.

6. A building comprising a front wall, a rear wall, and two side walls, wherein at least the front and rear walls are cavity wall structures as defined in any of the preceding claims, and wherein at ground level the laterally opposed precast concrete wall panels forming the wall leaves rest upon rising walls or other foundation structures, and the building includes a floor slab which forms the ground floor of the building and which is connected to the laterally spaced wall panels, forming at least the front and rear walls of the building, by connecting brackets which also connect the laterally spaced wall panels, each of the connecting brackets comprising a bridging part which bridges the cavity between the spaced wall panels and has two spaced apart upstanding fastening members one of which is received in a socket in the lower end face of one panel, and the other of which is received in a corresponding socket in the lower end face of the opposed panel, and the bracket has a strap portion which extends laterally therefrom and which is fastened to the floor slab.

7. A building as claimed in claim 6, having a ground floor level, and a first floor level, the front and rear walls of which are comprised of wall structures as defined in claim 3, and the building includes a first floor slab structure which is connected to the

laterally spaced wall panels by connecting brackets which also interconnect the laterally spaced wall panels of the upper and lower wall levels, the bracket comprising a bridging part which bridges the cavity between the laterally spaced wall panels at the joint between the upper wall level and the lower wall level, and adjacent each end of the bridging part there are opposed substantially vertically extending fastening members, the downwardly depending fastening members fitting within the sockets formed in the top edge faces of the lower level panels, and the upstanding fastening members fitting within corresponding sockets formed in the bottom edge faces of the upper level panels, and each bracket has a strap portion which extends laterally therefrom and is fastened to the upper floor slab.

8. A building as claimed in claim 7, wherein opposite edges of the floor slab structure abut the inner leaf of each opposite wall of the building and is connected thereto by the connecting brackets, and wherein at least one of the remaining opposite edges of the floor slab structure is supported on the upper end face of the inner leaf of the adjoining lower level wall.

9. A building as claimed in any of claims 6 to 8, wherein the front and wall structures are connected at ends thereof to a party wall which separates the building from an adjoining building having similar wall structures, and the inner ends of the inner leaves of the adjoining wall structures of each building overlap the end edge face of the party wall and are connected thereto by bolts which pass through a bolt-retaining plate hold in recesses in the ends of the wall panels, and the bolts are engagable with inserts in the end edge face of the party wall, and the inner and outer leaves of the wall structure are interconnected by connecting brackets.

10. An assembly as claimed in any of claims 1 to 5, or a building as claimed in any of claims 6 to 9, wherein sockets formed on the lower edge faces of the panels are of such dimensions that the fastening members, e. g. dowels, fit loosely within the sockets, and the sockets have access ports opening to the panel surface to enable grout, or similar fixing material, to be injected into the sockets.

11. A method of assembling a building substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.

12. A building panel substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.

13. A building substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.