WO2010100661A1

WO2010100661A1 - Modular building system

Info

Publication number: WO2010100661A1
Application number: PCT/IT2009/000083
Authority: WO
Inventors: Andrea Alberghina; Livio Barel; Lorella D'ortona
Original assignee: Andrea Alberghina; Livio Barel; D Ortona Lorella
Priority date: 2009-03-06
Filing date: 2009-03-06
Publication date: 2010-09-10

Abstract

A modular building system (10) having external walls consisting of prefabricated panels (16) which are vertically arranged side by side and placed between corner- pillars present at the change of direction of said walls. A cable loop (20) passes horizontally through all panels of each external wall, so as to stabilize them. The resulting structure is particularly simple to build and resistant.

Description

MODULAR BUILDING SYSTEM

DESCRIPTION

The invention relates to a modular building system.

The demand for buildings that can be erected quickly assembling prefabricated components is increasing. To satisfy it various solutions have been proposed in the art. For example CA 1 081 911 describes a building made of shaped blocks to be superimposed one over the other and hold together by a vertical passing-through cable.

U.S. 4 294 051 teaches how to build a medium-sized building by fixing panels to a structure of metal fins and stabilizing it with cables that pass inside the panels for the length of a wall. This system is not proposable for massive and heavy concrete structures.

In the case of masonry works the current solutions consider (see diagram SL in fig. 1 ) to construct a load-bearing structure of comer pillars P and intermediate wall columns C in reinforced concrete supporting the beams of the ceiling S. Then the span between the remaining pillars P, C is occluded with non-bearing curtain panels.

The assembly of large-sized wall panels can be achieved in various ways, the most used being:

- the rigid fixing on the joint present between a panel and the other by means of metallic flanges screwed with screws, as long as the size of the panel is equal to the size of the wall. These panels are very large, at least 3m in length, 3m in height and thickness varying between 20 and 50 cm;

- Fixing the joints between the panels with links cast during installation and then reinforced. It is obtained through vertical grooves arranged so as to form a cavaedium receiving a reinforcement cage and then a cast of concrete, to finally form a small pillar. The panels have horizontal links to ensure their adherence to the pillar.

Both solutions do not allow, however, to ensure full continuity of the system because of the possibility of detachment of the screws in the first case, and the imperfect adhesion of pillars with the panels in the second, besides the total absence of the shielding for thermal bridges.

The main object of the invention is to provide a modular building system with an improved assembly system. Another object is to allow the erection of a building more quickly than compared to the prior art. Still another object is to reduce the construction cost, installation time and labor resources.

These objects are achieved with the system defined in claim 1. Advantageous variants of the system are defined in the dependent claims.

The advantages and features of the invention will be more apparent from the following description of an exemplary embodiment, with the attached drawing in which: Fig. 1 shows schematically the structure of a known building;

Fig. 2 shows part of the bearing structure of a construction according to the invention;

Fig. 3 shows the path of a cable;

Fig. 4 shows a three-dimensional view of a vertical panel; Fig. 5 shows a plan view of two panels according to the invention placed side by side;

Fig. 6 shows a plan view of two known panels placed side by side;

Fig. 7 shows a side view of the base of a panel (enlarged detail of the dashed circle in Figure 2). Fig. 8 shows a three-dimensional view of a base kerb;

Fig. 9 shows a three-dimensional view of a kerb for a ceiling;

Fig. 10 shows a three-dimensional view of a horizontal panel for a ceiling.

Part of a building according to the invention, in the example having parallelepiped form with square base, is shown at 10.

It consists of a base or base floor 12 on which there are placed perimetrical base kerbs 14 acting as a pedestal for vertical panels 16 forming the external walls. Above the panels 16 are arranged perimetrical kerbs 30 on which are supported beams or horizontal floor panels 40. In the outer corners of the building 10, i.e. at the corners with change of direction for the exterior walls, there are pillars made of reinforced concrete (not shown). In Fig. 2 two walls are not drawn. The panels 16 are made of reinforced cellular concrete, with a density class of at least 50. This makes them adapted to support the structure above (i.e. they are load-bearing), very light (they weigh 1/4 of the concrete), excellent thermal and acoustic insulators, and breathable.

The example of building 10, in the light of current laws in the Applicants' country, can be used for buildings with up to two floors above ground, over which it is not allowed to have load-bearing walls.

It is a feature of the invention the presence of a cable 20, shown alone in Fig. 3, which forms two horizontal rings or loops 21a, 21b going through the base and the top of all the panels 16. The cable 20 is redirected several times and stretched at its ends through a tensioning member 22. The cable is inserted into channels or pipes arranged in the body of the panels 16 at the desired height, while the tensioning member 22 is preferably placed inside a corner pillar.

It is preferred using a cable coated with aramide, preferably made of steel, or a carbon fiber and aramide cable or a cable made completely of aramide, which has the advantage of offering low friction and simultaneously being very resistant to tension and shear. Too high a friction coefficient would not allow bending and pulling the cable 20 inside the building 10, let alone putting it in tension after the laying. Indeed it is difficult to pull a steel cable or the like along a tortuous path.

The changes of direction of the cable are facilitated by curved and/or saddle- shaped elements, preferably made of zinc-coated steel, adapted to greatly reduce if not completely cancel the friction of the cable into the pipes along curvatures.

The cable 20 serves to tighten the panels 16 between each other and avoids the complicated assembly methods of the prior art. It can also keep the entire building 10 elastic and with good anti-seismic qualities. During an earthquake the panels 16 cannot become detached from the concrete pillars because the cable 20 does not allow that, but allows them to wobble slightly thereby dissipating the destructive kinetic energy acquired and to discharge it to adjacent panels. The destructive energy of the earthquake is not borne only by 4-6 pillars as in the known art, but by a plurality of panels 16 which are all load-bearing, resilient and resistant. The building 10 reacts to the earthquake as a single elastic body due to the cerclage effect of the cable 20, being certainly more difficult to demolish than a series of isolated pillars.

Thus, the use of a cable (preferably two), at the same time very resistant to tension and shear, guarantees a very strong assembly between a panel 16 and the other, allowing at the same time a remarkable ease of assembly. When using a single loop of cable it is advisable to fix it at about half height of the pillars 16, windows and openings taken account of.

The connection of the panels 16 through the cable 20 also works with panels made of reinforced concrete, but a thicker cable and more cable rings are needed, because of their greater weight. Note that making the panels 16 load-bearing allows to remove from the structure 10 the concrete pillars C of the known art placed in the middle of a wall for supporting beams above. This decreases the costs and time of completion.

The panel 16 has a particular shape, which also solves the problem of reducing heat leakages and cancelling the thermal bridges, where as thermal bridge it is meant the part of the structure of a building with thermal characteristics very different from those surrounding it. A thermal bridge allows faster heat flows, and worsens the insulation of a building because it forms a path for the exchange of heat to and from the outside. The drawbacks of thermal bridges may be the cooling of the neighboring areas, thus creating condensation and hence mould, or the reduction of the insulation capacity of the wall. A thermal bridge is shown in Fig. 6 for two known panels 50 placed side by side, whose joint cavity 52 is filled with cellular concrete 54 during installation. The concrete 54 forms a thermal bridge that facilitates the flow of localized heat (see flow arrows F).

Fig. 4 and in particular fig. 5 shows the shape of the panel 16 and the connection with an adjacent panel. Preferred dimensions for the panel 16 are: width 70-80cm, height up to 360cm, thickness 30 to 40 cm. It has two parallel surfaces 17a, b, which will be facing respectively the outside and the inside of the building 10, while the sides exhibit a Z-shaped step 19. The steps 19 on the sides of a panel 16 are complementary, i.e. the right side of a panel may abut with matching the left side of the adjacent panel (see fig. 5). In the small space between the abutting sides is laid out a layer of insulating adhesive 21. The overlap of the two ends of adjacent panels 16 eliminates the problem of thermal bridges, because it ensures the continuity of the wall.

The base of the panels 16 is suitably shaped as well (see fig. 7). It is not flat but has a stepped or Z-shaped profile such as to match with the supporting kerb 14 which has a constant L-section and is complementary to the step. Such section has a thicker part 14a and a thinner part 14b. The base of the pillar 16 thus forms a step whose lower part should be turned to the outside of the building 10 (hence the socket 14a protruding toward the top of the kerb 14 should be turned to the inside). In this way the coupling between the base of the panel 16 and the kerb 14 creates a natural barrier to moisture and water (see flow-arrow H2O in Fig. 7) in the building 10.

The use of kerbs 14 as support for the panels 16 has another advantage. During the laying of the panels it is sufficient to smooth roughly the base 12 and to put exactly horizontal only the curbs 14, on a bed of mortar. So a lot of labor and installation time will be saved.

Preferred size of a kerb 14 are: depth 30 to 40cm, length up to 360 cm, height of part 14a about 10cm, and of part 14b about 7cm. It is preferred to make the kerb 14 in cellular concrete.

On top of the panels 16 is placed a plurality (or frame) of kerbs 30 with constant L- shaped cross-section. The raised portion of the kerbs 30 is arranged toward the outside of the panels 16, while on the flat part is placed a horizontal row of constant omega cross-section panels 40, made of cellular concrete. The panels 40 are joined to form a roof and rest on their major base. It is preferred to make the kerb 30 in cellular concrete, with a thickness of about 5-10cm. Preferred dimensions for the panel 40 are: width 70-80cm, length up to 700cm, height 20 to 30cm.

Above the panels 40 there is a cast of reinforced concrete 42, to fill their interstices in order to reinforce them. The end of the panels 40 on one side and the raised part of the kerbs 30 on the other in practice create a formwork (the void space indicated by 80). Inside the space 80 are placed iron cages, and then concrete is cast. At the end one gets a kerb in reinforced concrete which welds the panels 40 to the structure.

Claims

1. Modular building system (10) having external walls consisting of prefabricated panels (16) which are vertically arranged side by side and placed between corner- pillars present at the change of direction of said walls, characterized by comprising a cable loop (20) passing horizontally through all panels of each external wall.

2. System according to claim 1 , comprising two cable loops (21a, 21b) each passing horizontally through the panels of each external wall, and placed inside the base and the top of the panels, respectively.

3. System according to claim 1 or 2, wherein one or more cable loops are made of a single cable (20) deviated several times.

4. System according to any of the preceding claims, wherein the cable forming one or more loops is made of or coated with aramide.

5. System according to any of the preceding claims, wherein the panels exhibit two substantially parallel surfaces (17a, 17b) and two sides, where one side has a first shaping (19) and the other side has a second shaping (19) complementary to the first, so that, by putting side by side two panels, one of them partially overlaps the other perpendicularly to said substantially parallel surfaces.

6. System according to claim 5, wherein the first and second shaping are formed by means of a step conformation (19) and/or a Z-shaped conformation.

7. System according to any of the preceding claims, wherein the panels are designed to be weight-bearing.

8. System according to claim 7, wherein the panels are made of cellular concrete having a density class of at least 50.

9. System according to any of the preceding claims, comprising a supporting kerb (14) on which said panels can be laid and erected, said panels having a recessed base for shape-coupling the surface of the supporting kerb which is complementary thereto.

10. System according to claim 9, wherein the supporting kerb (14) has an L- shaped cross-section while the base of the panel has a complementary step thereto.

11. System according to any of the preceding claims, comprising a plurality of L- shaped kerbs (30) laid side by side above the top of the vertical panels (16) and on which horizontal panels (40) are resting, the L-shaped kerbs being adapted to leave between themselves and the horizontal panels a void space (80) acting as a formwork for putting a reinforcement framework and casting concrete therein.

12. System according to any of the preceding claims, comprising between the ends of a cable loop a tensioning member (22), which is adapted to stretch the cable and to be walled up into a corner pillar or a panel.

13. System according to any of the preceding claims, comprising at the changes of direction of the cable (20) curved elements and/or saddle-shaped elements, preferably made of zinc-coated steel, adapted to reduce the sliding friction of the cable.