WO1982003647A1 - Devices for improving the flexural strength of wood beams - Google Patents

Devices for improving the flexural strength of wood beams Download PDF

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Publication number
WO1982003647A1
WO1982003647A1 PCT/BE1982/000006 BE8200006W WO8203647A1 WO 1982003647 A1 WO1982003647 A1 WO 1982003647A1 BE 8200006 W BE8200006 W BE 8200006W WO 8203647 A1 WO8203647 A1 WO 8203647A1
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Prior art keywords
cable
beams
cables
hand
support
Prior art date
Application number
PCT/BE1982/000006
Other languages
French (fr)
Inventor
Henriette Wilggaut
Francois Zak
Thierry Zak
Original Assignee
Zak Telesphore
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from BE5/5228A external-priority patent/BE888355A/en
Priority claimed from BE5/5229A external-priority patent/BE888356A/en
Application filed by Zak Telesphore filed Critical Zak Telesphore
Publication of WO1982003647A1 publication Critical patent/WO1982003647A1/en

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
    • E04C3/292—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures the materials being wood and metal
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
    • E04C3/18—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with metal or other reinforcements or tensioning members
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
    • E04G21/12—Mounting of reinforcing inserts; Prestressing
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G23/00—Working measures on existing buildings
    • E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
    • E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G23/00—Working measures on existing buildings
    • E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
    • E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
    • E04G2023/0248—Increasing or restoring the load-bearing capacity of building construction elements of elements made of wood

Definitions

  • Modern constructions like those of yesteryear, often use wooden structures using planks, beams, beams. These elements are assembled to form a frame which is subjected to a set of static forces, assumed to be invariable, the result of which is vertical and directed downwards and passes through the center of gravity of the structure. Aging, bad weather, the weight of snow in the cold season, are elements that often have an influence such that the construction becomes fragile and that it is sometimes essential to consider strengthening or even replacing it.
  • These phenomena of weakening of a wooden structure are, today, much more frequent than formerly: the forest which the modern man exploits is made of less deciduous trees and the coniferous species which populate it are cut in any season , saturated with resins that accelerated drying methods do not sufficiently remove fibers.
  • the young woods proposed to serve as beams are highly elastic and efforts have been made to improve their resistance to bending. It is well known to reinforce a wooden structure by propping it by resting on the nearest flat surface (generally the attic). This obviously has major disadvantages (possible sagging of the support surface). Apart from an improvement in drying techniques and shoring, no particular technique can strengthen the planks. The strongest beams are laminated and are known.
  • the essential idea of the invention is the use of steel cables, the tension of which is adjusted so as to increase the static resistance characteristics of a beam.
  • FIG. 1 An embodiment of the invention is visible in Figure 1 in which there is shown a beam modified according to the method mentioned above: a cable follows, along the beam, the path with groove, from the mark 1 to mark 5.
  • the beam placed horizontally has its upper extreme angles cut at 45 ° and 135 °. Perpendicular to the surfaces thus made, a hole is drilled from 5 to 4 and from 1 to 2 respectively.
  • the lower part 2, 3, 4 of the beam is grooved in the middle 8.
  • Three plates 6 serve to fix and hold the cable in place. Each plate is screwed diagonally.
  • two tensioning devices 11 are provided (blocking cone 11 and plates 10) which put the cable under tension.
  • the same beam, statically modified and in the pre-tensioned state, according to the invention, has an arrow of 11 mm under 500 kgs . only and the breaking limit is raised to 1760 kgs. (without collapse).
  • the same idea of reinforcement by metal cable is the basis of a second embodiment according to the invention and illustrated in FIG. 2.
  • the wooden beam 9 (resting on the walls 14) has two fixing ends 1 and 6 , in general rafters of the roof.
  • a metallic hand is moreover capable of sliding along the beam while conforming to its shape.
  • the metal hand 8 is provided with a support 10 to which it is welded.
  • the base of the support is connected on the left to a cable going from the fixing 4 towards the cable clamp 5 by encircling the beam at 6. Similarly symmetrically, the right cable follows the path 3, 2, 1. (2 designated the greenhouse -right cable).
  • the references 11 and 12 designate cable tensioners (with left and right screw threads).
  • the reinforcement of the wooden beam 9 using the support according to the invention is therefore easily conceivable.
  • the metal hand is fixed vertically to the center of gravity of the assembly constituted by the beam to be reinforced and by its load. In practice, for reasons of symmetry, the metal hand is placed in the center of the beam. For exceptional cases where the distribution is not symmetrical, the graphostatic methods make it possible to determine the location of the metallic hand.

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Composite Materials (AREA)
  • Rod-Shaped Construction Members (AREA)

Abstract

Use is made of the tensioning of a steel cable to reduce the sag either of beams of young conifers or of installed beams which have become weak by an overload or xylophagous attack. In the first case, the steel cable (wires) follows, along one groove (8) the length of the beam, goes through it to the left (4-5) and to the right (1-2) at 45 % and is finally tensioned at its extremities (1 and 5) thereby effectively prestressing the beam. In the second case, a hanging clamp (8) with a support (10) is arranged perpendicularly to the beam and passes by the plane of the gravity center of the beam and of its load. On either side of the metal hanging clamp (8) and of its support (10), two cables (2-1, 5-6) are tensioned along one path embracing the beam at both its ends. The tensioning is carried out by means of screwing tie rods (11 and 12) so as to bring the mechanical sag of the assembly back at a desired level and compatible with the diameter of the steel cables.

Description

DISPOSITIFS D'AMELIORATION DE LA. RESISTANCE A LA FLEXION DE POUTRES EN BOIS. DEVICES FOR IMPROVING THE. RESISTANCE TO BENDING OF WOODEN BEAMS.
Les constructions modernes, comme celles d'autrefois, font appel souvent à des structures en bois mettant en oeuvre des madriers, poutrelles, poutres. Ces élément sont assemblés pour former une charpente qui est soumise à un ensemble de forces statiques, supposées invariables dont la résultante est verticale et dirigée vers le bas et passe par le centre de gravité de la structure. Le vieillissement, les intempéries, le poids de la neige en saison froide, sont des éléments qui ont souvent une influence telle que la construction se fragilise et qu'il est parfois indispensable d'envisager son renforcement voire même son remplacement. Ces phénomènes d'affaiblissement d'une structure en bois sont, de nos jours, beaucoup plus fréquents qu' autrefois : la forêt que l'homme moderne exploite est faite de moins de feuillus et les essences résineuses qui la peuplent sont coupées en toute saison, gorgées de résines que les méthodes de séchage accéléré éliminent insuffisamment des fibres. La résistance à la traction de la future poutre est déjà compromise au départ par le choix même de l'essence du bois et par la manière dont ce dernier est traité. Il a paru indispensable, vu cet état de fait, de chercher, au départ d'une poutre usuelle en construction moderne (par exemple Sapin rouge (ou blanc) du Nord, séché aux rayons infra-rouges et stocké en hangar à l'air libre environ six mois) d'en augmenter la résistance statique. Dans la même ligne d'idées, de telles poutres en bois résineux jeunes (ou des poutres plus anciennes sèches, mais affaiblie par une invasion de parasites xylophages que l'on aurait enrayée) peuvent même installées dans une structure de construction, être renforcée pour offrir plus de sécurité. L'objet de la présente invention est double : d'une part améliorations de la résistance mécanique d'une poutre avant sa mise en oeuvre, d'autre part renforcement d'une poutre installée qui ne présente pas Joutes les garanties de résistance.Modern constructions, like those of yesteryear, often use wooden structures using planks, beams, beams. These elements are assembled to form a frame which is subjected to a set of static forces, assumed to be invariable, the result of which is vertical and directed downwards and passes through the center of gravity of the structure. Aging, bad weather, the weight of snow in the cold season, are elements that often have an influence such that the construction becomes fragile and that it is sometimes essential to consider strengthening or even replacing it. These phenomena of weakening of a wooden structure are, today, much more frequent than formerly: the forest which the modern man exploits is made of less deciduous trees and the coniferous species which populate it are cut in any season , saturated with resins that accelerated drying methods do not sufficiently remove fibers. The tensile strength of the future beam is already compromised at the outset by the very choice of the type of wood and the way it is treated. It seemed essential, given this state of affairs, to search, starting from a usual beam in modern construction (for example Northern red (or white) fir, dried with infrared rays and stored in a hangar in the air free about six months) to increase the static resistance. In the same line of ideas, such young softwood beams (or older dry beams, but weakened by an invasion of xylophagous parasites that would have been checked) can even be installed in a construction structure, be reinforced to provide more security. The object of the present invention is twofold: on the one hand improvements in the mechanical resistance of a beam before its implementation, on the other hand reinforcement of an installed beam which does not have resistance guarantees.
Les bois jeunes proposés pour servir de poutres sont fortement élastiques et l'on a cherché à améliorer leur résistance à la flexion. Il est bien connu de renforcer une structure en bois en étançonnant celleci en prenant appui sur la surface plane la plus proche (en général le grenier). Ceci présente évidemment de gros désavantages (affaissement possible de la surface d'appui). A part une amélioration des techniques de séchage et l'étançonnage, aucune technique particulière ne permet de renforcer les madriers. Les poutres les plus résistantes sont lamellées et sont connues. L'idée essentielle de l'invention est l'usage de câbles d'acier dont la tension est réglée de manière à augmenter les caractéristiques de résistance statique d' une poutre. On sait, en effet, que la section transversale de toute poutre est le siège d'efforts équivalent à une force ~
Figure imgf000004_0001
et à un couple
Figure imgf000004_0002
La force
Figure imgf000004_0003
est dé composable en composante longitudinale (effort de
Figure imgf000004_0004
traction ou de compression, suivant le cas) et en composante transversale (effort tranchant ou de cisail
Figure imgf000004_0005
lement). De même le coupe C'est dé—composable en couple de torsion et couple de flexion.The young woods proposed to serve as beams are highly elastic and efforts have been made to improve their resistance to bending. It is well known to reinforce a wooden structure by propping it by resting on the nearest flat surface (generally the attic). This obviously has major disadvantages (possible sagging of the support surface). Apart from an improvement in drying techniques and shoring, no particular technique can strengthen the planks. The strongest beams are laminated and are known. The essential idea of the invention is the use of steel cables, the tension of which is adjusted so as to increase the static resistance characteristics of a beam. We know, in fact, that the cross section of any beam is the seat of efforts equivalent to a force ~
Figure imgf000004_0001
and a couple
Figure imgf000004_0002
Strength
Figure imgf000004_0003
is de composable in longitudinal component (effort of
Figure imgf000004_0004
tension or compression, as the case may be) and in transverse component (shear or shear force
Figure imgf000004_0005
). In the same way the cut It is decomposable in couple torsional and bending torque.
Un mode de réalisation de l'invention est visible à la figure 1 dans laquelle on a représenté une poutre modifiée selon le procédé évoqué ci-dessus : un câble suit, le long de la poutre, le trajet avec rainure, allant du repère 1 au repère 5. La poutre placée horizontalement a ses angles extrêmes supérieurs coupés à 45° et à 135°. Perpendiculairement aux surfaces ainsi pratiquées un trou est foré de 5 vers 4 et de 1 vers 2 respectivement. La partie inférieure 2, 3, 4 de la poutre est rainurée en son milieu 8. Trois plaques 6 servent de fixation et de maintien du câble en place. Chaque plaque est vissée en diagonale. Aux extrémités 1 et 5 eu câble on a prévu deux dispositifs de mise sous tension 11 (cône de blocage 11 et plaques 10) qui mettent le câble sous tension. Cette mise sous tension a pour effet de diminuer les composantes des efforts résiduels
Figure imgf000005_0001
et
Figure imgf000005_0002
ci-dessus évoqués et de mettre la structure véritablement à l'état précontraint. Pour la plaque 5 centrale, il y a lieu de clouer de part et d'autre 2 pitons de manière à maintenir le câble au milieu lors de la traction pratiquée. Comparativement : une poutre d'un même bois (sapin rouge du Nord : section 6,5 × 17,5 cm2, longueur : 5,4 m) sous une charge de 500 legs (10 sacs de 50 kgs équidistants) présente une flèche de 31 mm. ; sa limite de rupture à une forte traction sur les fibres est de 900 à 1000 kgs (avec éclatement), La même poutre statiquement modifiée et à l'état précontrait, selon l'invention, présente, sous 500 kgs, une flèche de 11 mm. seulement et la limite de rupture est remontée à 1760 kgs. (sans effondrement). La même idée de renforcement par câble métallique est à la base d'un second mode de réalisation selon l'invention et illustrée à la figure 2. La poutre en bois 9 (reposant sur les murs 14) comporte deux extrémités de fixation 1 et 6, en général chevrons de la toiture. Une main métallique est d'autre part susceptible de coulisser le long de la poutre tout en épousant sa forme. La main métallique 8 est munie d'un support 10 auquel elle est soudée. La base du support est reliée à gauche à un câble allant de la fixation 4 vers le serre câble 5 en encerclant la poutre en 6. De même symétriquement, le câble de droite suit le trajet 3, 2, 1. (2 désignât le serre-câble de droite). Les repères 11 et 12 (voir Fig. 2) désignent des tendeurs de câble (à g pas de vis gauche et droit). Le renforcement de la poutre en bois 9 à l'aide du support selon l'invention se conçoit dès lors aisément. La main métallique est fixée à la verticale du centre de gravitté de l'ensemble constitué par la poutre à renforcer et par sa charge. En pratique, pour des raisons de symétrie la main métallique est placée au centre de la poutre. Pour des cas d'exception ou la répartition n'est pas symétrique, les méthodes de la graphostatique permettent de déterminer l'emplacement de la main métallique. On peut également placer de part et d'autre du support droit entre les points de fixation 3 et 4 et les tendeurs 11 et 12 deux dynamomètres. La position de la main métallique est déterminée pour que, avec un réglage identique des tendeurs, la lecture dynamométrique soit lauême à gauche et à droite du support. (Annulation du moment résultant de l'ensemble des forces de l'assemblage). Les avantages obtenus grâce à ce renforcement de poutre usagée sont évidents dans le cas de réfection de vieilles bâtisses : de vieilles poutres qui présentent une flèche importante et une dégradation avancée sont redressées jusqu'à annulation totale de la flèche. Il va de soi que le choix du diamètre du câble, celui des deux dispositifs de mise sous tension 11 et 12 font partie du savoir faire de l' homme de l'art et ne sont pas l'objet de la présente invention, qui par contre, présente dans une même idée de renforcement des performances statiques d'une poutre à l'aide de câbles, deux modes de réalisation permettant d'une part de précontraindre une poutre jeune et d'autre part de renforcer la résistance à la charge d'une poutre installée plus ancienne, douteuse au point de vue de la sécurité et dont le remplacement est financièrement peu envisageable. An embodiment of the invention is visible in Figure 1 in which there is shown a beam modified according to the method mentioned above: a cable follows, along the beam, the path with groove, from the mark 1 to mark 5. The beam placed horizontally has its upper extreme angles cut at 45 ° and 135 °. Perpendicular to the surfaces thus made, a hole is drilled from 5 to 4 and from 1 to 2 respectively. The lower part 2, 3, 4 of the beam is grooved in the middle 8. Three plates 6 serve to fix and hold the cable in place. Each plate is screwed diagonally. At the ends 1 and 5 of the cable, two tensioning devices 11 are provided (blocking cone 11 and plates 10) which put the cable under tension. This energizing has the effect of reducing the components of the residual forces
Figure imgf000005_0001
and
Figure imgf000005_0002
above mentioned and to put the structure truly in the prestressed state. For the central plate 5, it is necessary to nail on both sides 2 pitons so as to keep the cable in the middle during the traction practiced. Comparatively: a beam of the same wood (northern red fir: section 6.5 × 17.5 cm 2 , length: 5.4 m) under a load of 500 legs (10 bags of 50 kg equidistant) has an arrow 31 mm. ; its breaking limit at high tensile strength on the fibers is 900 to 1000 kgs (with bursting), The same beam, statically modified and in the pre-tensioned state, according to the invention, has an arrow of 11 mm under 500 kgs . only and the breaking limit is raised to 1760 kgs. (without collapse). The same idea of reinforcement by metal cable is the basis of a second embodiment according to the invention and illustrated in FIG. 2. The wooden beam 9 (resting on the walls 14) has two fixing ends 1 and 6 , in general rafters of the roof. A metallic hand is moreover capable of sliding along the beam while conforming to its shape. The metal hand 8 is provided with a support 10 to which it is welded. The base of the support is connected on the left to a cable going from the fixing 4 towards the cable clamp 5 by encircling the beam at 6. Similarly symmetrically, the right cable follows the path 3, 2, 1. (2 designated the greenhouse -right cable). The references 11 and 12 (see Fig. 2) designate cable tensioners (with left and right screw threads). The reinforcement of the wooden beam 9 using the support according to the invention is therefore easily conceivable. The metal hand is fixed vertically to the center of gravity of the assembly constituted by the beam to be reinforced and by its load. In practice, for reasons of symmetry, the metal hand is placed in the center of the beam. For exceptional cases where the distribution is not symmetrical, the graphostatic methods make it possible to determine the location of the metallic hand. It is also possible to place on either side of the straight support between the fixing points 3 and 4 and the tensioners 11 and 12 two dynamometers. The position of the metal hand is determined so that, with an identical adjustment of the tensioners, the torque reading is the same on the left and right of the support. (Cancellation of the moment resulting from all the forces of the assembly). The advantages obtained with this reinforcement of used beams are obvious in the case of repair of old buildings: old beams which present a significant deflection and an advanced deterioration are straightened until total cancellation of the deflection. It goes without saying that the choice of the diameter of the cable, that of the two tensioning devices 11 and 12 are part of the know-how of those skilled in the art and are not the object of the present invention, which by against, present in the same idea of strengthening the static performance of a beam using cables, two embodiments allowing on the one hand to prestress a young beam and on the other hand to strengthen the resistance to the load d '' an older installed beam, dubious from the point of view of safety and whose replacement is financially unlikely.

Claims

REVENDICATIONS . CLAIMS.
1. Dispositif de renforcement statique d'une poutre en bois à l'aide de câbles ou fils d'acier caractérisé en ce que la poutre est pourvue d'une part d'une rainure longitudinale lelon de laquelle court le câble, d'autre part de deux orifices à 45 degrés par rapport à la poutre et en ce que le câble traverse les deux orifices et est coiicé dans la rainure.1. Static reinforcement device for a wooden beam using steel cables or wires, characterized in that the beam is provided on the one hand with a longitudinal groove along which the cable runs, on the other hand part of two holes at 45 degrees to the beam and in that the cable passes through the two holes and is coiicée in the groove.
2. Dispositif selon la revendication ci-dessus caractérisé en ce que les deux extrémités 1 et 5 du câble sont munis de cônes de blocage 11 permettant une mise de la poutre à l'état précontraint par tension suivant la charge à supporter.2. Device according to claim above characterized in that the two ends 1 and 5 of the cable are provided with locking cones 11 allowing the beam to be put in the prestressed state by tension according to the load to be supported.
3. Dispositif de renforcement statique à l'aide de câbles ou fils d'acier, d'une poutre en bois, mise ou non sous charge, caractérisé en ce que dans le plan du centre de gravité de la poutre on place une main métal lique munie d'un support aux extrémités duquel deux câ bles aboutissent, effectuant chacun les lacets (4,5,6) et (3,2,1) respectivement autour de la poutre et qui sont tendus à l'aide des serre-câbles 10 et 11 de manière à ramener la flèche mécanique de l'ensemble à un niveau souhaité et compatible avec le diamètre des câbles d'acier. 3. Static reinforcement device using steel cables or wires, a wooden beam, whether or not under load, characterized in that in the plane of the center of gravity of the beam a metal hand is placed lique provided with a support at the ends of which two cables terminate, each effecting the laces (4,5,6) and (3,2,1) respectively around the beam and which are stretched using cable ties 10 and 11 so as to bring the mechanical deflection of the assembly to a desired level and compatible with the diameter of the steel cables.
PCT/BE1982/000006 1981-04-09 1982-04-07 Devices for improving the flexural strength of wood beams WO1982003647A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
BE5/5228A BE888355A (en) 1981-04-09 1981-04-09 FRAME SUPPORT,
BE5228 1981-04-09
BE5/5229A BE888356A (en) 1981-04-09 1981-04-09 Prestressed wooden beam
BE5229810409 1981-04-09

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2150969A (en) * 1983-12-06 1985-07-10 Dinardo And Partners Restoring and strengthening of timber components
FR2585393A1 (en) * 1985-07-29 1987-01-30 Renofors France Beam or other construction element made of timber which is reinforced by means of a reinforcing element, and method for its manufacture
FR2627210A1 (en) * 1988-02-11 1989-08-18 Antignac Paul Pre-stressed joint esp. for plywood beam - comprises cylindrical elements with holes for tensioned steel wires
DE4242525A1 (en) * 1992-12-16 1994-06-23 Jurck Hans Henrich Multipart support component for large hall roof
US20130239512A1 (en) * 2010-03-19 2013-09-19 Weihong Yang Steel and wood composite structure with metal jacket wood studs and rods
RU2512147C2 (en) * 2012-08-07 2014-04-10 Александр Григорьевич Леонтьев Strut beam
EP2868829B1 (en) * 2013-10-30 2017-12-13 M Lefevre Method for reinforcing a timber construction element by assembling a reinforcement module placed under post-tension
RU2718572C2 (en) * 2017-10-27 2020-04-08 Федеральное Государственное Бюджетное Образовательное Учреждение Высшего Образования "Дагестанский Государственный Технический Университет" (Дгту) Reinforced glued laminated beam
IT202000000640A1 (en) * 2020-01-16 2021-07-16 Arsenio Borgnini SALVA CAPRIATA TENSIONING SYSTEM

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Publication number Priority date Publication date Assignee Title
CH255339A (en) * 1945-11-03 1948-06-30 Muther Adolf Prestressed wooden beam.
US2601910A (en) * 1944-05-16 1952-07-01 Thomas F Nichols Composite structural member
US2856644A (en) * 1955-07-05 1958-10-21 Royal J Ahlberg Joist brace
US3251162A (en) * 1962-01-25 1966-05-17 Pierce J Strimple Laminated prestressed beam construction
BE888356A (en) * 1981-04-09 1981-07-31 Wilgaut H Prestressed wooden beam
BE888355A (en) * 1981-04-09 1981-07-31 Wilgaut H FRAME SUPPORT,

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2601910A (en) * 1944-05-16 1952-07-01 Thomas F Nichols Composite structural member
CH255339A (en) * 1945-11-03 1948-06-30 Muther Adolf Prestressed wooden beam.
US2856644A (en) * 1955-07-05 1958-10-21 Royal J Ahlberg Joist brace
US3251162A (en) * 1962-01-25 1966-05-17 Pierce J Strimple Laminated prestressed beam construction
BE888356A (en) * 1981-04-09 1981-07-31 Wilgaut H Prestressed wooden beam
BE888355A (en) * 1981-04-09 1981-07-31 Wilgaut H FRAME SUPPORT,

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2150969A (en) * 1983-12-06 1985-07-10 Dinardo And Partners Restoring and strengthening of timber components
FR2585393A1 (en) * 1985-07-29 1987-01-30 Renofors France Beam or other construction element made of timber which is reinforced by means of a reinforcing element, and method for its manufacture
FR2627210A1 (en) * 1988-02-11 1989-08-18 Antignac Paul Pre-stressed joint esp. for plywood beam - comprises cylindrical elements with holes for tensioned steel wires
DE4242525A1 (en) * 1992-12-16 1994-06-23 Jurck Hans Henrich Multipart support component for large hall roof
US20130239512A1 (en) * 2010-03-19 2013-09-19 Weihong Yang Steel and wood composite structure with metal jacket wood studs and rods
US8820033B2 (en) * 2010-03-19 2014-09-02 Weihong Yang Steel and wood composite structure with metal jacket wood studs and rods
RU2512147C2 (en) * 2012-08-07 2014-04-10 Александр Григорьевич Леонтьев Strut beam
EP2868829B1 (en) * 2013-10-30 2017-12-13 M Lefevre Method for reinforcing a timber construction element by assembling a reinforcement module placed under post-tension
RU2718572C2 (en) * 2017-10-27 2020-04-08 Федеральное Государственное Бюджетное Образовательное Учреждение Высшего Образования "Дагестанский Государственный Технический Университет" (Дгту) Reinforced glued laminated beam
IT202000000640A1 (en) * 2020-01-16 2021-07-16 Arsenio Borgnini SALVA CAPRIATA TENSIONING SYSTEM

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AU8336182A (en) 1982-11-04
EP0076812A1 (en) 1983-04-20

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