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 according to the preamble of claim 1.
• 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 in the bracket anchoring and forwarded; 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 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 deformation modulus, 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.
• a tension member which has fiber components, is prestressed in a central region of its length and glued to the concrete surface of a supporting structure. In its two end regions, the tension member is received in a clamping device which is connected to the supporting structure via a plastically deformable transmission element.
• the plastically deformable transmission element forms a composite, the deformation modulus of which is significantly higher than that of the adhesive composite in the central region of the tension member. Since the anchoring of the traction means at its end regions only becomes effective when the traction means is overloaded over its entire central region, ie not in the event of local overloads, the risk of breakage in the area of cracks is not avoided.
• 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 creep losses are excluded at the same time.
• This object is achieved in that the second deformation module is significantly lower than the first deformation module.
• the non-prestressed protrusion in the two end areas of the tension member serves as anchoring and reinforcement. Since an adhesive composite with a low deformation modulus, ie a largely rigid adhesive composite is used in this non-prestressed area, the prestressing force is largely transferred into the concrete without creep losses.
• the surface-flush arrangement of the band-shaped tension member prevents the occurrence of an offset moment.
• a separate anchoring and back-up reinforcement is not necessary, since these functions are achieved in a particularly simple and 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 device for carrying out the method with a band-shaped tension member to be arranged on the concrete surface of the structure, tensioning devices and end anchors acting thereon, the tensioning device having a force introduction body which is non-positively connected to the band-shaped tension member and which, in the longitudinal direction of the tension member, is fixed to the structure is displaceable, and wherein a tension drive can be used between the force introduction body and the base body.
• a tension drive can be used between the force introduction body and the base body.
• This tensioning device which is arranged at one or preferably at both ends of the central, prestressed area of the tension member, creates the possibility in a structurally simple and space-saving manner to apply 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 unstressed.
• a band-shaped tension member 3 is applied to the concrete surface 2, which consists, for example, of carbon fibers.
• the central area 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 In its central, prestressed area 3a, 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. In its two end regions 3b, 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 is 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 T-shaped force introduction body 10 is attached with its T-stem 10a to the underside of the band-shaped tension member 3, preferably glued and is arranged in a recess 11 of the base body 8, that the force introduction body 10 also in the recess 9 of the Concrete surface 2 is sunk.
• the connecting surface which is preferably connected by adhesive bond to the tension member 3, ie the upper side of the T-arm 10a of the force introduction body 10 lies in the plane of the concrete surface 2.
• 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 arranged on both sides of the T-arm 10a, 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.
• the tension member 3 is prestressed in its central region 3a on the concrete surface 2 before the first adhesive compound 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 sheet metal pieces with which the force introduction 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 introduction 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 thus 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 subsequent end region 3b.
• 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 composite and fixed to the concrete surface 2 with this.
• Fig. 8 it is shown that several band-shaped tension members 3, 3 'can be applied one after the other.
• the lowest band-shaped tension member 3 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.

Landscapes

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

Applications Claiming Priority (3)

Publications (2)

Family

ID=7843513

Family Applications (1)

Country Status (7)

Families Citing this family (25)

Family Cites Families (10)

• 1997
  • 1997-09-24 DE DE19742210A patent/DE19742210A1/de not_active Withdrawn
• 1998
  • 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 WO PCT/EP1998/006099 patent/WO1999015744A1/de not_active Ceased
  • 1998-09-24 AT AT98955408T patent/ATE263296T1/de active
  • 1998-09-24 EP EP98955408A patent/EP1025323B1/de not_active Expired - Lifetime
  • 1998-09-24 DE DE59811116T patent/DE59811116D1/de not_active Expired - Lifetime
  • 1998-09-24 DK DK98955408T patent/DK1025323T3/da active

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