BUILDING SYSTEM WITH A LOAD-RESISTING FRAME MADE OF REINFORCED CONCRETE OR STEEL INTEGRATED WITH WOODEN INFILL PANELS

Abstract

A construction system with a new or pre-existent supporting framework, made of reinforced concrete or steel, integrated with infill panels made of wood. The supporting framework is constituted by a frame of columns and beams. The infill panels are inserted and put under stress in one or more fields of the frame of the structure, forcedly and without play all along their perimeter.

Claims

1-4. (canceled)

5. A construction system with a supporting framework, new or pre-existent, made of reinforced concrete or steel, integrated with infill panels made of wood, wherein said supporting framework is constituted by a frame of columns and beams, wherein said infill panels are inserted and put under stress in one or more fields of the frame of the structure, forcedly and without play all along their perimeter.

6. The construction system according to claim 5, wherein said infill panels are made of laminated wood.

7. The construction system according to claim 6, wherein said infill panels are made of cross-laminated wood.

8. The construction system according to claim 5, wherein said infill panels are integrated in a frame.

Description

[0047] The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiment, with particular reference to the figures of the accompanying drawings, in which:

[0048] FIG. 1 shows a perspective view of an infill panel inserted in a frame of reinforced concrete according to the present invention,

[0049] FIG. 2 shows a perspective view of a detail of the panel and the frame of FIG. 1, during assembly,

[0050] FIG. 3 shows a perspective view of a further detail of the panel and the frame of FIG. 1, during assembly,

[0051] FIG. 4 shows a plan sectional view of a detail of the panel and the frame of FIG. 1, assembled,

[0052] FIG. 5 shows a plan sectional view of a covering panel inserted in a frame made of steel according to the present invention, assembled,

[0053] FIG. 6 shows a plan view of the load-bearing structure of a building, in which some wooden infill panels are inserted, according to the present invention,

[0054] FIG. 7 shows a representative model of the displacements in the horizontal direction of the elements of the frame made of reinforced concrete of a building, with brick panels as infills, for comparative purposes,

[0055] FIG. 8 shows a representative model of the displacements in the vertical direction of the elements of the frame made of reinforced concrete of a building, with brick panels as infill, for comparative purposes,

[0056] FIG. 9 shows a representative model of the displacement in the horizontal direction of the elements of the frame made of reinforced concrete of a building, with cross-laminated wood panels as infill, according to the present invention,

[0057] FIG. 10 shows a representative model of the displacements in the vertical direction of the elements of the frame made of reinforced concrete of a building, with cross-laminated wood panels as infill, according to the present invention,

[0058] FIG. 11 shows a representative model of the stress state of the reinforced concrete columns of the frame of a building, with brick panels as infill, for comparative purposes, and

[0059] FIG. 12 shows a representative model of the stress state of the frame-reinforced concrete columns of a building, with cross-laminated wood panels as infill, according to the present invention.

[0060] The present invention is essentially based on the replacement of infill elements made of bricks with infill elements made of wood; the elements having sometimes structural reinforcement function, as in the case of the bracing elements, made of laminated wood panels and preferably of laminated wood with glued crossed lamellas, such as the panel marketed by KLH with the name X-Lam; and sometimes with perimeter infill function and partition walls, as in the case of elements of external and internal vertical closing.

[0061] The bracing elements, within the load-bearing skeleton of a building, are configured as special constraints that prevent the structure to carry out a displacement or a rotation due to a horizontal force induced by seismic events of average and high intensity.

[0062] The higher tensile strength and higher ductility of the wooden panels compared to masonry panels made of brick, allows to avoid the elastic-fragile behavior of the infills and to improve the distribution of pressing loads on the columns. This results in a substantial increase in the ability to dissipate energy, such as to increase the load bearing capacity of the structure, thus allowing a global seismic upgrading of buildings.

[0063] As regards the elements of internal and external vertical closing, the use of dry-layered infills allows easy redistribution of the environments, improving the flexibility of the plant and allowing to adapt the system to the different possibilities of use, while the inclusion of perimeter wooden infills contributes to improving the energy performance of the building envelope.

[0064] In accordance with the requirements dictated by law and by the rules of proper design, the earthquake resistant infills made of laminated wood with crossed lamellae have to be positioned symmetrically and uniformly distributed both in plan and elevation, so as to counter the torsional motions of the building in case of side actions.

[0065] To ensure the effectiveness of the proposed solution, it is essential the correct execution of the details concerning the connections between the wooden bracing infills and the frames made of reinforced concrete or steel. In fact, to have an adequate effectiveness of the bracing effect of the infills made of cross-laminated wood, the last must be appropriately forced in their respective fields of the frames, in order to eliminate any possible play and thus make the bracing active since the first occurrence of a horizontal action (wind or earthquake).

[0066] So, for the purposes of the present invention, the wooden panels made of cross laminated wood must be forcedly placed along the entire perimeter inside frames made of reinforced concrete or steel of buildings already existing or to be realized.

[0067] The way in which this is achieved is not important, different assembling alternatives are apparent to experts in the field on the basis of the teachings of the present invention.

[0068] In other words, to be structurally efficient, the wooden panels, preferably made of laminated wood and more preferably made of cross-laminated wood, must be, regardless the adopted method of laying in work, inserted forcedly and without play, all along their perimeter, within the field of the frame (made of reinforced concrete or steel) in which they are inserted.

[0069] Referring to FIGS. 1-4, it is shown, for purposes of example only and not of limitation, a simple embodiment of the present invention, in which a wooden panel, indicated by the reference number 10, is laid in place and forcedly put all around its perimeter in a frame 11 made of reinforced concrete, consisting of columns 12 and beams 13, according to a very simple and generic method, used by way of example but not of limitation of the present invention, by means of a wooden counter-frame 14. In the figures, the panel 10 is in turn integrated in a frame 15, also made of wood. Again with reference to FIGS. 1-4, the forced insertion of the panel 10 is obtained, by way of example and not of limitation, by inserting between the panel 10, or better between the frame 15 of the panel 10 and the counter-frame 14, a plurality of wedges 16. In particular, FIG. 1 and FIG. 4 show the constituent elements of the construction system according to the present invention subsequently to the forced insertion, with wedges 16 tightly packed between the counter-frame 14 of the building structure and the frame 15 of the panel 10, and FIG. 2 and FIG. 3 show the same items before forced insertion.

[0070] This particular embodiment of the present invention is very similar to that of installation of the doors, with the difference in that, while between the frames and the counter-frames it is sufficient to put four wedges, two for each vertical upright, according to the present invention putting into force must be made all along the perimeter of the panel 10, with the exception of the base (automatically forced by putting into force the upper side 10 of the same panel), through a suitable number of wedges 16.

[0071] If desired, in the case of columns 12 made of steel or reinforced concrete with perfectly vertical faces, it could also be possible to put into force only one of the vertical sides of the panel 10.

[0072] In particular, FIG. 4 shows how the panel 10 is made integral with the frame 15 due to the action of coupling effected by screws 17, which preferably may be double thread screws 17. By contrast, the counter-frame 14 also is made integral with the column 12 made of reinforced concrete due to the effect of the coupling action operated by respective screws 18. In FIG. 4 is also shown a further screw 19, which preferably may be a double thread screw 19, by which the panel 10, by means of its frame 15, the counter-frame 14 and the wedges 16 are rendered integral with each other, after the putting into force of the system.

[0073] FIG. 5, very similar to FIG. 4, presents the difference that the supporting skeleton of the building is made of steel, so that, instead of the column 12 made of reinforced concrete shown in FIG. 4, in FIG. 5 a column 20 of steel with double-T type profile is shown.

EXAMPLE

[0074] The study of the applicability of the construction system according to the present invention analyzed the general problems of public housing built in Italy in the first half of the XX century and has addressed, in line with the emerging policies of environmental sustainability and reduction of energy consumption, the theme of sustainable restoration of existing buildings by intervening on the particular case study of Preturo ATER district; a small residential settlement located on the outskirts of L'Aquila and characterised by a low level of livability, made worse by the withdrawal as a result of the serious damage caused by the earthquake of April 2009.

[0075] The study allowed to evaluate the applicability of the technology in dry conditions according to the present invention, in the building restoration, verifying how this system is particularly suitable for the improvement of seismic behavior of structures and of the energy behavior of the envelope.

[0076] The restoration project was an important case study on which it was possible to analytically verify the effective functioning of the proposed solution, verifying how with this intervention it is possible to achieve a substantial improvement in the overall seismic behavior of the structure.

[0077] The area forming object of study consists of six buildings arranged as a court and having 3 and 4 floors above ground.

[0078] The six buildings have same construction-structural characteristics: rectangular plan with a size of 39.3 m in the X direction and 12 m in the Y direction and an elevation above ground of 3 and 4 floors with a height of 11.3 m and 14.1 m.

[0079] The load bearing structure, made of reinforced concrete frame, is made up of columns with a size of 3060 cm and beams which can be divided into emerging beams 3050 cm and beams with 6030 cm thickness.

[0080] The typical deck is made with floors in brick-concrete, consisting of rows of perforated brick blocks and reinforced concrete joists with overhanging cooperative slab and transverse warp at the lower side of the building. The infills instead are made in hollow brick and chalk blocks.

[0081] In compliance with the requirements dictated by the regulations in force and of the rules of proper design, as shown in FIG. 6, in which there is shown a plan view of the load-bearing structure of one of the buildings, the panels 10, constituting bracing walls, realized in cross-laminated wood X-Lam, were arranged symmetrically and uniformly distributed in plan and in elevation, thereby reducing the tendency of the structure to twist due to side actions induced by an earthquake.

[0082] The evaluation of structural type has allowed to observe the different dynamic behavior of the structure stressed by seismic action and evaluate the aspects that cross-laminated wood X-Lam technology can offer in restoring infill framed structures.

[0083] The analysis made was of the dynamic linear type with acceleration spectrum response. Through the analysis it was possible to evaluate, in terms of deformation and even better in terms of participants masses, the substantial differences in the behavior of the frames of reinforced concrete infilled with brick panels (referred to in the FIGS. 7 and 8, respectively, as about the displacement in the X direction and the displacement in the Y direction) and of reinforced concrete frames infilled with panel of cross-laminated wood X-Lam (referred to in FIGS. 9 and 10, respectively, with respect to the displacement in the X direction and the displacement in Y direction).

[0084] From the evaluation of the structural weight of the two modeling the improving contributions in terms of reduction of the masses were observed, which of course become part in the dynamic analysis.

[0085] In the model studied with X-Lam panels a drastic reduction of the structural weight was observed, which implied a significant reduction of seismic shear on the building (the latter being nothing more than a cutting action to the base, proportional to the mass of the building and the design spectrum referred to the first return period) and then in an equally significant reduction (up to 20 times) of the etched displacements.

[0086] In the same models the different stress state of columns with different type of panels was then rated (referred to in the FIGS. 11 and 12, respectively, with regard to infills with brick panels and with regard to infills with cross-laminated wood panels X-Lam), noting that the inclusion, in one or more fields of the frame of the structure, of panels made of cross-laminated wood, forcedly and without play all along their perimeter, according to the present invention, give to the structure evident improvements in terms of reduction of tensions.

[0087] In particolar, in the tensional state stress beam earthquake bending y=bending by torsion, it was recorded a reduction of approximately 75% of the stress state of the columns, in the case of the model with infill of cross-laminated wood X-Lam panels (for which a maximum stress has been calculated to be 4.01 N/mm2), compared to the case of the model with brick infill (for which a maximum stress equal to 16.47 N/mm2) was calculated.

[0088] The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that variations and/or modifications can be made by those skilled in the art without departing from the relevant scope of protection, as defined by the enclosed claims.