US2022950A - Reenforcing structure in buildings - Google Patents

Description

Dec. 3, 1935. P. BUZZONI I REENFORCING STRUCTURE IN BUILDINGS I Filed Aug. 3, 1953 4 Sheets-Sheet 1 Dec. 3, 193 5. V BUZZON] 2,022,950

REENFORCING STRUCTURE IN BUILDINGS Filed Aug. 3, 1933 4 Sheets-Sheet 2 Dec. 3,' 1935. v

P. BUZZONI REENFORCING STRUCTURE IN BUILDINGS Filed Aug. 3, 1933 4 Sheets-Sheet 3 Dec. 3, 1935; P. BUZZONI REENFORCING STRUCTURE IN BUILDINGS Filed Aug. 3, 1933 4 Sheets-Sheet 4 Patented Dec. 3, 1935 UNlTED STATES PATENT OFFICE Paride Buzzoni, Rome, Italy, assignor to Soc. An. Commercio Industria Edili, S. A. C. I. E., Rome,

Italy Application August a, 1933, Serial No. 683,543 In Italy August 4, 1932 4 Claims.

In the modern practice of building or restoring old structures, the following problems are frequently to be solved: securing stability also against sismic action in house building or in any other masonry work; reenforcement of existing masonry works erected without regard to sismic action in order to make them resistant against same; consolidation of the foundations of masonry walls in order to check or to prevent the settlement or sliding of these or to allow superelevation or higher loads; putting in girders or beams to reenforce ceilings, vaults or domes in old or new buildings; restoring any kind of masonry work in order to reenforce it, so as to allow a high load or great openings; conservation of old and staggering masonry structures of historical or artistical interest, and so on.

The various systems hitherto employed for the solution of these construction problems showed in practice a great number of inconveniences and sometimes were quite irrational, especially as, in view of obtaining a full warranty of stability at present not reached in a convenient manner, the usual structures have been completely abandoned notwithstanding their experienced advantages from technical, economical and hygienic standpoints.

Thus, for instance, in the construction of antisismic buildings, having a supporting cage in reenforced concrete of the usual type (with vertical struts and horizontal booms of a full rectangular section, forming together large bays or meshes, horizontally connected by the ceilings of reenforced concrete), this cage alone having to ensure the general resistance of the building, the vertical bays are usually filled with wall structures of the lightest kind, as they have only to separate one room from the, other. Such a structure has all the inconveniences of thin walls, such as insufficient protection against heat, cold, moisture and sound, and is not apt to take up any shock. On the other hand, in such a system of supporting cage the masonry work being excluded from any participation in the totalresistance of the building, forms only a dead weight, or, what is worse, it increases the shocks against the skeleton of the building, so as to require a supporting cage of excessive proportions if ordinary walls should be used to fill the bays.

Concerning the safety, it must be observed that the system of a cage does not afford sufficient protection, as the walls are badly connected with the girders and the struts, especially on the upper side of the walls, a settlement being unavoidable in these. This system is quite inappropriate for the purpose of antisismic consolidation of existing buildings executed in normal masonry, as it is difiicult, or even impossible, 5 to insert the usual supporting cage in the wall structure without disconnecting it by cutting it into independent fields.

One comes to similar conclusions on examining the various other systems of antisismic 10 building hitherto proposed, as, for instance, a system having a non-supporting cage, either in iron, reenforced concrete or even wood, as these cages connect only common masonry or special masonry in little blocks of artificial stone or in 15 hollow brickwork.

In a general way, it may be said that none of the systems already proposed corresponds perfectly to its purpose, as the antisismic buildings should olfer, together with the special guarantee 20 of stability, also any normal guarantee of hygiene and long duration, of good cohesion between walls and supporting cage, of a high insulating power against heat, cold, humidity and sound, and of adaptability to eventual modifications and rebuilding. All these guarantees would be obtained only if the antisismic structure syste'ms would satisfy to the conditions of adaptability to the normal masonry structures.

On the contrary, the reenforcing structure, ac- 3O cording to the invention, is of a universal, easy and cheap application adapted to the reenforcement of normal as well as of any other masonry work of old or new structure.

Moreover, it fully solves all the problems of modern building mentioned in the introduction, and particularly of antisismic bu-ilding,'and consists essentially in the formation of booms or reenforcing ribs solid with the masonry or independent from it, adapted to bring to the desired degree of security the insufiicient resistance of any masonry structure.

The reenforcing structure which forms the object'of the present specification is essentially formed by a girder, or rib, having a section, which is partially, i. e. at intervals, hollow in proximity of its axis of symmetry, and which may becomposed of two or more principal elements or flanks, connected at intervals by secondary transversal elements or joints rigidly connecting the two flanks.

Relative to the masonry structure, the girder is so executed that the two flanks applied on the two sides of the masonry are rigidly connected by the joints which are applied across the masonry.

Any material is more or less suitable to form this supporting or reenforcing structure, such as iron, reenforced concrete, and even wood; and

' porting cage and masonry work, solid or, if necessary, independent one from the other.

With a certain number of these girders, connected together in a convenient manner, it is possible to form in the inside of any masonry work a real reenforcing woof, which, if it is proportioned by form and dimension to the peculiar scope, will ensure a perfect stability to these masonry works.

In contradistinction to the aforesaid known systems of antisismic supporting structures have ing a supporting cage of full section dividing the full or hollow masonry work in single bays or fields and not representing a complete solution of the problems of antisismic building, the reenforcing structure type according to the invention is based on the principle of using a PBIfO-r rated supporting structure traversed by fullmasonry work, and abandons the old principle of a plain supporting structure, filled by hollow walls. The new system has useful applications in new as well as in old buildings of ordinary masonry structure. Its application is also use? ful in restoring works, in the superelevation and consolidation of buildings and particularly in antisismic buildings, and ensures a perfect inser-,

tion of the masonry in the supporting structure with the advantage of maintaining the continuity of the masonry work and of utilizingits important contribution to. the stability of same Without the necessity of supporting its weight, which, naturally, is discharged on the foundations. W

In practice, the type of the reenforcing cage may be realized outside or inside the existing masonry work by using various proceedings, ac.-, cording to the problems to be solved.

In the annexed drawings are demonstrated some of these methods applied to the solution of certain cases often occurring in the practice of.

modern building.

Fig. l is a perspective detail showing the use of a beam for strengthening a wall with the flanks of the beam embedded in the wall,

Fig. 2 is a top plan view thereof,

Fig. 3 is a top plan view of the flanks of the beam or strut anchored against the outside of the wall,

Fig. 4 is a perspective detail of the arrangement shown in Fig. 3,

Fig. 5 is a perspective view of a slightly modified form in which the wall is reenforced by a girder, the flanks of which are disposed exteriorly of the wall,

Fig. 6 is a perspective detail of a slightly modified arrangement of an interconnected beam and girder,

Fig. 7 is a perspective detail showing the connection between the two girders,

Fig. 8 is a top plan detail of the invention as applied to an L-shaped wall,

Fig. 9 isa top plan detail of a modification of the arrangement as applied to cross walls,

Fig. '10 is a similar view showing an application of the invention to a Wall of T-shaped formation, 5

Fig. 11 is a perspective view showing the invention applied to a cross Wall formation with the flanks of the beams or struts anchored against the outer surface of the wall,

Fig. 12 is a top plan view of the arrangement shown in Fig. 11,

Fig. 13 is an elevational detail of a further modification of the invention,

Fig. 14 is a perspective detail of a further modification constructed in the form of a cage, 15

Figs. 15, 16 and 1'? show top plan views of further modified forms of the invention in which flanks of the beams or struts are imbedded on one side wall and anchored exteriorly of the other side wall, 20

Figs. 18 to 22 inclusive are perspective views of modified forms of joints,

Figs. 23 to 26 inclusive are perspective views of iron joints,

Fig. 27 is a perspective view of a part of the wall in which the reenforcement includes iron flanks,

Fig. 28 is a perspective view of a wall with iron flanks of channel-shaped formation imbedded therein,

Fig. 29 is a. perspective view of a further form of the invention,

Fig. 30 is a perspective view of the ceiling re;- enforcement,

. Fig. 31 is a perspective view showing the in- 35 vention applied to foundation plates for buildings,

Fig. 32 is a perspective view showing the in,- vention applied to a superelevation on an old building, 4o

enforcement applied about the doorway of a 15 building,

Fig. 36 is a perspective view showing a further modification of the invention applied to a wall,

Fig. 37 is a perspective view showing a modification of the invention applied to the ceiling and floor structure, and

Fig. 38 is a perspective vie Showing a further modification as applied to a wall structure.

As it is evident from the drawings, the two flanks f and f of the beam T, which are applied to the two faces of the wall P, are connected the one to the other at certain intervals, the length of which will be determined according to any specific case, by the joints 9, also reenforced, which render the flanks solidar-y between themselves.

The total section of the beam is in this Way comparable with the section of a common pile of rectangular section, in which a number of trans: versal holes has been made to allow the masonry to traverse the pile. V

In the Fig. 2 the flanks and f are completely embedded in the masonry, in other cases, as shown in Fig. 3 they may be also disposed par-. tially ortotally outside the masonry work. 7

The typical structure of a reenforcing cage, according to the invention, is such that vertical struts M or horizontal girders, C may beegrecuted in new buildings together with the masonry itself In this case it is convenient to prepare outside 76 the building yard only the reenforced joints and to insert them into the masonry during the proceeding of same, in the place of the common masonry material, at the desired intervals, as is shown in Fig. 4.

In this case, the extent of wall P, under notice, will show, when finished, a series of joints g which form part of the masonry but have their extremities free of their iron reenforcement, allowing their connection with the reenforcing irons of the flanks ,f and which complete the flanks and the strut M, when they have been embedded in a layer of concrete.

With a quite similar method the horizontal girder C is executed and in this case the joints 9 Will be introduced into the masonryin correspondence to a horizontal layer and disposed on edge. Afterwards, their reenforcing irons will be connected with the horizontal and longitudinal irons for the formation of the flanks f and f necessary to complete the girder C.

These girders may also be executed with the flanks wholly or partially embedded in the wall or totally outside of the masonry.

The execution of a complex of beams or struts and girders may give a system of rectangular meshes or bays which forms a cage for antisismic buildings.

The union of a strut M with a girder C or the union of two girders, C and C is shown as an example in the Figures 6 and '7.

This union may be realized in correspondence to the joints, or for increased security, the girders may be of full section near their point of union.

Corresponding to the meeting of the walls in form of L, T or in cross form, not always the elevation of a vertical strut is necessary in the reenforcing structure according to the invention, but if they are adopted they may be executed with flanks of only one or of more elements outside or inside the masonry, as demonstrated by Figures 8 and 13.

The flanks beside the executions as shown, wholly or partially embedded in the masonry work or outside of it, may also assume different forms, such as U or T, polygonal, curved or columnar form (see Figs. 15, 16 and 17), solving at the same same static as Well as aesthetic problems.

The joints also, beside the normal parallelepipedic form, may assume various other forms as a conical or a dowel form and so forth. They may be disposed in one or in more directions or alternated in two senses as shown in the Figures 14, 18, 19, 20, 21, and 22.

For masonry work of small height, the system may be applied in a simplified form, reducing the joints and the flanks to the iron reenforcement only, thus forming a kind of reenforced masonry work as shown on Fig. 27.

In this case, the armature of the joints must be fixed with cement mortar to the masonry structure and in analogy the iron reenforcement of the flanks must be embedded in the 65mm mortar after having been connected with the transversal reenforcements of the joints.

In order to justify the denomination of iron reenforcing structure for this system, it is necessary that all its elements be executed in iron only, as is shown on Fig. 28, in which the flanks of the beams are formed by two flat irons or by a U-iron.

In this type of a cage-structure the connections between the flanks and the joints must be very accurate and all the elements of the cage protected and fixed with fine mortar in order to avoid the formation of rust.

The different types of joints in iron alone, of which the Figures 23-26 reproduce a few samples, may also be applied in the execution of the 5 reenforcing structures in concrete, as it has been described, thus giving origin to a series of intermediate types in mixed material, in which the section, the form and the composition of the flanks and of the joints as well as the kind of 10 connection, may vary and be combined in the best convenient manner.

The Fig. 29 shows how in a reenforcing structure in reenforced concrete for strengthening new antisismic buildings, a ceiling S in reinforced con- 15 crete may be connected by its small girders with the inner side of the main girders C and C The Fig. 30 shows the application of the structure, according to the invention, to the reenforcing of old buildings in the zone corresponding to 20 the common ceiling in iron, and vaults or slabs.

The Fig. 31 gives a sample of the application of the structure to a foundation plate for buildings. It shows how it may form a plan of foundation and contribute to the distribution of pres- 25 sure, when the flanks and f are conveniently enlarged, for instance in the form of L, with or without reenforcing ribs.

In this application the joints g have, as it is evident, a different function, as they represent, 30 besides their normal function of connecting and reenforcing the flanks, the means for the transmission of load to the flanks themselves, as it happens in any supporting beam.

The greatest advantage and the characteristi- 5 cal feature of the reenforcing structure, according to the invention, consist in the fact that the structure is adapted to the reenforcement of old buildings in normal masonry and, in a general line, to the strengthening of all the works which 40 must be restored, consolidated and superelevated; particularly if the said building has been originally erected without regard to antisismic resistance and is now to be transformed in a building of exceptional stability, as required by 45 the rules of antisismic construction.

The reenforcing construction, according to the invention offers these advantages as the beams or girders composing same may be formed gradually by placing first the joints and executing 50 the flanks afterwards.

It will indeed be suflicient, in the cases of consolidation, to open in correspondence with the vertical struts or with the horizontal girders, to be constructed, the holes necessary for introduc- 55 ing the joints in the masonry work of the foundations, walls, vaults, domes or the like, to be reenforced. These holes are disposed or alternated in a convenient manner and are perforated one at a time or two, at the utmost, so as 60 to avoid the weakening of the existing masonry. After having introduced a joint in the hole prepared, same is accurately refilled with cement mortar in order to re-establish perfectly the wall structure before other holes are being drilled. 65 When the joints corresponding to a single girder are inserted into the masonry, the girder may be finished by connecting to the irons of the joints the longitudinal irons of the flanks and embedding these irons in a layer of concrete or 70 cement mortar by means of boards which may be taken down after a fortnight.

This gradual proceeding, if applied to the enlargement of old foundations in intermediate levels of middle depth, allows the consolidation 75 tween the new beams and the old structure. separating material is afterwards withdrawn so as to allow a small free space which is suflicient ofthe foundations of buildings without making it necessary to touch or to lay open the masonry work of the existing foundation.

In the case of superelevation of buildings having an insuflicient thickness of walls, the new system may also be used. When applied to the existing masonry, it allows, in the case of sufficiently solid foundations or after a reenforcemerit of same, as described, or after a suffi cient foundation of the vertical beams of the reenforcing structure, the execution of any superelevation as shown in Fig. 32, without any alteration to the old masonry. But the beams-in this case, must be made in a slightly different manner, that is to say, the cementation of the joints with the old masonry must be delayed until the beams are finished and put under the new load.

This result is due to the particular form of the reenforcing structure according to the invention, which allows to make, at will, the new structure independent from the old masonry work, so that after having reached with the vertical struts the level of the old flat roof, and after having connected to these the horizontal girders supporting the superelevation, this latter may be executed with the new or with any old system, according to the scope to be reached.

The reenforcing structure may be advantageously applied also to masonry walls to which must be fixed mechanical transmission means as it permits the supporting beams being entirely independent from the walls.

This can be realized by inserting during the construction thin metal sheets, or the like, be-

The

to prevent the propagation of the oscillations or of any other force. The same scope may be reached by'filling the free space between the new and the old structure with compressible material, such as cork, tar or other material, which may remain in the construction when the supporting structure is finished without interfering with the required independence.

The reenforcing structure has another advantageous application in the consolidation of vaults (V in Fig. 23) or of domes (Fig. 24), consisting in the possibility of gradual execution as well as the various functions which may be attributed 1 to the girders in view of their form, their reenforcement and their general disposition.

Another application of the system, similar to the application on foundations, is for forming supporting arches or girders to protect or conserve delapidated Walls or to allow the making of great openings, without endangering the existing wall by deep recesses. (Fig. 35.)

During the execution of the restoring works, the consolidation of foundations, walls or vaults, or during the superelevation of a building, the rooms of this building may be used without interruption, as these works do not weaken the existing walls.

The reenforcing structure may also be used for the equal and continuous strengthening of new or old walls, on their whole extent, as by a reenforcing woof, applied in one direction only (Fig. 36), or in two directions (Fig. 38), horizontally and vertically, or inclined. On the crossing points may be placed the joints; whilst the flanks may be continuous or discontinuous.

This special application of the reenforcing structure, according to the invention, makes a wall adapted to resist to the highest strain acting perpendicularly to the wall, and for this reason the system may serve also for strengthening or for building new ceilings having girders in one direction or in two incrossing directions with continuous flanks.

In this case, the procedure adopted for the execution is different, the inferior girder being formed first, then the slabs are being placed, leaving free the space for the joints, in order to allow the joint irons to be embedded in the mortar and to be connected afterwards with the irons of the superior flank, as it may be observed in the example given by Fig. 37.

The advantage of reenforcing structures, according to the invention, may be resumed as follows:

Possibility of application to any kind of building and to any part of the building, resistance against any kind of strain, possibility of execution without trouble or interruption of the use of the building, possibility to realize, at will, independence or interindependence between the reenforcing structure and the reenforced structure, economy of material due to the conservation of the structive functions and of the advantages of the normal masonry structure.

What I claim as my invention is:

l. A reenforcing structure for walls comprising a series of reenforcing joints anchored in transverse. holes in the wall, each of said joints including a body, longitudinally arranged reenforcing bars imbedded therein and having end portions extending freely beyond the ends of the body, a plurality of bars arranged on opposite sides of the wall and across. the ends of the joints and connected to the freely extending end portions of the bars, and cementitious flanks arranged about the last mentioned bars and anchored to the surfaces of the walls.

2. A reenforcing structure as claimed in claim 1, wherein the joints and bars are constructed in the form of a cage.

3. In a reenforcing structure, a wall provided with a series of transverse holes and with grooves on opposite sides communicating with the holes, reenforcing joints anchored in the holes and each including a body, longitudinally arranged reenforcing bars anchored in the body and having end portions extending freely beyond the ends of the body and into the grooves, a plurality of bars arranged on opposite sides of the wall and within the grooves and connected to the freely extended end portions of the reenforcing bars, and cementitious flanks arranged about the last mentioned bars and anchored in the grooves.

4. A reenforcing structure as claimed in claim 3, wherein the wall is provided with holes arranged in rows extending horizontally and vertically thereof and wherein the grooves also extend vertically and horizontally in the wall.

PARIDE BUZZONI.

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