Classifications

• • 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
  • E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic 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
  • E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements
  • E04G2023/0255—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements whereby the fiber reinforced plastic elements are stressed
  • E04G2023/0259—Devices specifically adapted to stress the fiber reinforced plastic 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
  • E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements
  • E04G2023/0262—Devices specifically adapted for anchoring the fiber reinforced plastic elements, e.g. to avoid peeling off

Definitions

• the invention relates to a method for upgrading and / or renovating reinforced concrete or prestressed concrete structures, wherein a prestressed band-shaped tension member is connected to the concrete surface of the structure by means of a composite.
• brackets made of steel or reinforced concrete are anchored to the concrete surface, and the tension member is stretched between these brackets. Due to the offset between the axis of the tension member and the concrete surface, however, an unfavorable offset moment arises, which has to be recorded and forwarded in the bracket anchoring; in addition, a bond between the tension member and the concrete surface can not be made.
• high-strength, thin and therefore comparatively light strips are preferably used as tension members.
• These bands made of high-strength materials usually behave linearly elastic until they break; a flowing plateau, i.e. an area with constant force approximated by the expansion path does not appear with such high-strength materials.
• an adhesive composite in areas where cracks have to be bridged, an adhesive composite can be selected which itself has a certain deformability, ie has a high modulus of deformation, so that in the event of a crack opening, expansion compensation in the tension member can take place over a length which is significantly greater than the increase in the crack width.
• Such adhesive composite with a high deformation modulus are unsuitable as permanent anchoring because of the creep losses associated therewith.
• the object of the invention is to overcome the disadvantages mentioned and to provide a method for retrofitting and / or renovating reinforced concrete or prestressed concrete structures in which the risk of breakage in the range of avoiding an offset moment when the band-shaped tension member is directly applied to the concrete surface Cracks avoided, but at the same time creep losses can be excluded.
• the tension member is prestressed only in a central region of its length and is connected to the concrete surface by means of a first composite with a high deformation modulus and that the tension member is connected at its two end regions in the non-prestressed state to the concrete surface by means of a second compound with a low deformation modulus.
• the first and the second composite means are preferably adhesive composite means.
• the non-prestressed overhang in the two end regions of the tension member serves as anchoring and reinforcement. Since in this non-prestressed area an adhesive composite with a low deformation modulus, i.e. a largely rigid adhesive compound is used, the prestressing force is largely transmitted to the concrete without creeping losses.
• the surface-flush arrangement of the band-shaped tension member prevents the occurrence of an offset torque.
• a separate anchoring and reinforcement is not necessary, because these functions are particularly simple and can be achieved in a space-saving manner by the rigid adhesive connection of the non-prestressed end regions of the traction means to the concrete surface.
• the invention further relates to a band-shaped tension member for upgrading and / or renovating reinforced concrete or prestressed concrete structures.
• the tension member according to the invention is characterized in that the tension member is prestressed only in a central region of its length and to the concrete surface by means of a first composite means, preferably adhesive composite means is connected to a high deformation module and is connected at its two end regions in the non-prestressed state to the concrete surface by means of a second compound, preferably with a low deformation module.
• the tension member can consist of steel, plastic or preferably carbon fibers.
• the invention also relates to a device for carrying out the method with a band-shaped tension member arranged on the concrete surface of the structure, tensioning devices acting thereon and end anchors.
• this device is characterized in that the tensioning device has a force-transmitting body which is non-positively connected to the band-shaped traction means and which is m It is displaceable in the longitudinal direction of the traction mechanism that a tensioning drive can be used between the force-transmitting body and the base body and that at least one spacer can be used between mutually facing abutment surfaces of the base body and the force-transmission body.
• This tensioning device which is arranged at one or preferably at both ends of the central, prestressed area of the tension member, creates in a structurally simple and space-saving manner the possibility of applying the required pretensioning force to the middle area of the tension member, the two end areas lying beyond the force introduction points of the tension member remain untensioned.
• 1 is a simplified representation of a reinforced concrete or prestressed concrete structure with an attached tension member
• FIG. 4 is a view of the tensioning device in the direction of arrow IV in FIG. 2,
• FIG. 5 is a view of the tensioning device in the direction of arrow V in Fig. 3,
• FIGS. 2-5 shows the clamping device according to FIGS. 2-5 in an exploded view
• FIG. 7 in a representation corresponding to FIG. 1, a reinforced concrete or prestressed concrete structure with a tension member applied by a modified method
• Fig. 8 in a schematic longitudinal section, the ends of several superimposed tension members.
• a band-shaped tension member 3 which consists for example of carbon fibers, is applied to its concrete surface 2.
• the central region 3a of the tension member 3 is prestressed between two force introduction points 4 by a prestressing force indicated by arrows 5 in FIG. 1.
• the tension member 3 is not prestressed in its two end regions 3b located beyond the force introduction points 4.
• the band-shaped tension member 3 is connected to the concrete surface 2 by means of a first adhesive compound which has a relatively high modulus of deformation.
• the tension member 3 is connected to the concrete surface 2 by means of a second adhesive compound, which has a deformation module that is considerably lower than that; this second adhesive compound is largely rigid in the hardened state.
• a tensioning device 7 is arranged at each of the two force introduction points 4, as shown in FIGS. 2-6.
• Each tensioning device 7 has a plate-shaped base body 8 which is fastened to the base of a flat recess 9 of the concrete surface 2, preferably glued on.
• a in plan T-shaped Kraftem effets 1969 10 is attached with its T-stem 10a on the underside of the band-shaped tension member 3, preferably glued and is so m a recess 11 of the base body 8 that the Kraftem effets crusher 10 also m of the recess 9 Concrete surface 2 is sunk.
• the connecting surface connected to the connecting member 3, preferably by gluing, ie the upper side of the T-arm 10a of the force introduction body 10 lies in the plane of the concrete surface 2.
• connection between the T-shaped force introduction body 0 and the band-shaped tension member 3 can alternatively also be carried out as follows:
• the T-arm 10a can be made longer than shown;
• a second T-shaped force introduction body (not shown) can on the first force introduction body
• lamellae for example steel lamellae
• the tension member 3 can be glued to the tension member 3 and connected to the force introduction body 10, for example also glued or positively connected.
• a hydraulic or mechanical tensioning element of a tensioning drive 12 which is supported on the base body 8, acts on the two T-arms 10b of the force introduction body 10.
• the tensioning drive 12 has two hydraulic tensioning cylinders 12a which are arranged on both sides of the T-arm 10a and which act on the two T-arms 10b.
• An angular cover 13 is connected to the base body 8 and serves to fasten the tensioning drive 12. After application, the tension member 3 is prestressed in its central region 3a on the concrete surface 2 before the first adhesive composite has hardened between the tensioning drives 7 of the two force application points 5.
• At least one spacer 14 is used between mutually facing abutment surfaces 10c of the force introduction body 10 and abutment surfaces 8a of the base body 8.
• the spacers 14 consist of a plurality of pieces of sheet metal, with which the force transmission body 10 is wedged relative to the base body 8.
• the tensioning drive 12 can be removed from the tensioning device 7 in order to be used for prestressing another tension member.
• the force transmission body 10 is also provided on its underside with an adhesive compound which hardens to a largely rigid adhesive connection after the tensioning process.
• the end regions 3b of the tension member 3 are fixed to the concrete surface 2 by means of an adhesive compound which is largely rigid after hardening.
• the end regions 3b attached to the concrete surface 2 in this way form a reinforcement for the two ends of the tension member 3.
• the pretensioning force for the central region 3a was introduced at two force introduction points 4 each lying between the central region 3a and the adjoining end region 3b. Deviating from this, it is shown in FIG. 7 that the pretensioning force 5 can be introduced via force introduction points 4 'located at the ends of the tension member 3 after the first adhesive composite has been applied only in the central region 3a.
• the ends of the tension member 3 are detached, for example cut off, from the tensioning devices arranged at the force introduction points 4 '.
• the end regions 3b of the tension member 3 are folded up, provided with the second adhesive compound and fixed to the concrete surface 2 with this.
• a plurality of band-shaped tension members 3, 3 ' can be applied one above the other.
• the lowest band-shaped tension member 3 m is applied to the concrete surface 2 in the manner already described.
• a second band-shaped tension member 3 ' is again placed on the top of the first band-shaped tension member 3 with an adhesive composite with a high deformation modulus (represented by a wavy line).
• the clamping devices 7 arranged at the two ends apply the required pretensioning force.
• the end of the tension member 3' is separated from the tensioning device 7 in the manner described.
• the end regions 3b ' are folded up, coated with the adhesive compound with a low deformation modulus and glued to the concrete surface 2.
• This process can be repeated several times in order to apply a plurality of tension members one above the other, the end regions 3b, 3b '... being rigidly attached directly to the concrete surface 2.
• the tensioning device 7 can be completely detached from the concrete surface 2; instead, only the base plate 8 can remain, while all other parts of the clamping device 7 are removed.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Structural Engineering (AREA)
• Working Measures On Existing Buildindgs (AREA)
• Reinforcement Elements For Buildings (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
• Joining Of Building Structures In Genera (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7843513

Family Applications (1)

Country Status (7)

Cited By (3)

Families Citing this family (22)

Citations (2)

Family Cites Families (8)

• 1997
  • 1997-09-24 DE DE19742210A patent/DE19742210A1/de not_active Withdrawn
• 1998
  • 1998-09-24 DE DE59811116T patent/DE59811116D1/de not_active Expired - Lifetime
  • 1998-09-24 DK DK98955408T patent/DK1025323T3/da active
  • 1998-09-24 AT AT98955408T patent/ATE263296T1/de active
  • 1998-09-24 WO PCT/EP1998/006099 patent/WO1999015744A1/de not_active Ceased
  • 1998-09-24 JP JP2000513026A patent/JP4152070B2/ja not_active Expired - Fee Related
  • 1998-09-24 US US09/509,259 patent/US6385940B1/en not_active Expired - Lifetime
  • 1998-09-24 EP EP98955408A patent/EP1025323B1/de not_active Expired - Lifetime

Patent Citations (2)

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