CN201206337Y

CN201206337Y - Prestressed concrete structure

Info

Publication number: CN201206337Y
Application number: CNU200820004915XU
Authority: CN
Inventors: 陈明留; 王杰; 周春辉; 石磊
Original assignee: China Construction Third Engineering Bureau Co Ltd
Current assignee: China Construction Third Engineering Bureau Co Ltd
Priority date: 2008-03-14
Filing date: 2008-03-14
Publication date: 2009-03-11
Anticipated expiration: 2018-03-14

Abstract

The utility model discloses a prestressed concrete structure. The prestressed concrete structure is characterized in that the structure comprises an original structural concrete layer (7). A prestressed tendon bunch (6) is arranged in the original structural concrete layer (7); a concrete layer (8) which is cast at the first time is arranged on the original structural concrete layer; the prestressed tendon bunch is radial in the concrete layer which is cast at the first time, and the other end of the prestressed tendon is bunchy; a concrete layer (9) which is cast at the second time is arranged outside the concrete layer (8) which is cast at the first time; and the tail end of the prestressed tendon bunch (6) is a separated prestressed tendon (2) which is arranged in the concrete layer (9) which is cast at the second time. The prestressed concrete structure has the advantages of safety, quickness, cost saving and social benefit. Furthermore, the utility model solves the engineering problem that an unbonded prestressed structure which has been built or is being built needs to be reconstructed because of the change of the purpose of a building. Therefore, the construction difficulty is low.

Description

Prestressed reinforced concrete construction

Technical field

The utility model belongs to the building structure reconstruction field, relates to a kind of prestressed reinforced concrete construction.

Background technology

Prestressed reinforced concrete construction is not generally done transformation after building up, but in recent years, because the change of building purposes and need the engineering of building up or the prestressing without bondn structure of Hot work in progress is transformed often being occurred, because the presstressed reinforcing steel stretch-draw of original structure finishes, have higher pre-tensile stress, cutting off prestressing force can be to the amount of deflection of prestressed structure, cracks etc. produce considerable influence, the work progress safety requirements is high especially simultaneously, the characteristics that are limited to prestressed reinforced concrete construction itself and construction, the prestressed reinforced concrete construction transformation is compared with the ordinary concrete structure of modification, has certain difficulty of construction.

If the presstressed reinforcing steel of having constructed directly cuts off, the presstressed reinforcing steel of that stretch-draw is with in the indentation concrete beam plate, and presstressed reinforcing steel will lose efficacy, and cuts muscle and put Zhang Shihui to produce bigger retraction, and moment produces huge relaxation force simultaneously, and degree of danger is quite high.So must prestressed structure be transformed guaranteeing that structural safety does not promptly influence under the prerequisite of prestressing effect and construction safety in beam and the plate.

The content of utility model

Technical problem to be solved in the utility model provides a kind of prestressed reinforced concrete construction, removes strengthening construction at the increasing prestressed reinforced concrete construction of present appearance, and this structure can be safely in work progress, quick, saving cost.

Technical problem to be solved in the utility model is achieved through the following technical solutions:

A kind of prestressed reinforced concrete construction comprises the original structure layer of concrete, is provided with the presstressed reinforcing steel bundle in the described original structure layer of concrete; Described original structure layer of concrete is provided with the layer of concrete of cast for the first time, and described presstressed reinforcing steel bundle presents outside radial in the layer of concrete of the described cast first time, and the other end is a pencil; Outside the layer of concrete of the described cast first time, be provided with fluid concrete layer for the second time; The end of described presstressed reinforcing steel bundle is for the presstressed reinforcing steel that separates, in the fluid concrete layer inside second time.

The layer of concrete of described original structure layer of concrete, cast for the first time and be respectively equipped with first hole, second hole and the 3rd hole on the layer of concrete of presstressed reinforcing steel 2 tops in the fluid concrete layer for the second time.

Described presstressed reinforcing steel bundle the layer of concrete of original structure layer of concrete, cast for the first time and for the second time the fluid concrete layer distribute for disconnecting.

Described second time, the fluid concrete layer was provided with a layer of concrete to some cast outward.

The utility model has following advantage:

1, safety, quick, saving cost, obvious social benefit.

2, solved because the change of building purposes and need be to the engineering problem that builds up or the prestressing without bondn structure of Hot work in progress is transformed, at the bottom of the difficulty of construction.Be to guarantee that structural safety does not promptly influence the structure of under the prerequisite of prestressing effect and construction safety in beam and the plate prestressed structure being transformed.

Description of drawings

Fig. 1 is the prestressed reinforced concrete construction schematic diagram.

Fig. 2 is the cut-out schematic diagram of Fig. 1 presstressed reinforcing steel.

The specific embodiment

Below in conjunction with accompanying drawing the utility model is done and to be described in further detail:

A kind of prestressed reinforced concrete construction as shown in Figure 1 and Figure 2 comprises original structure layer of concrete (7), is provided with presstressed reinforcing steel bundle 6 in the described original structure layer of concrete 7); Described original structure layer of concrete (7) is provided with the layer of concrete (8) of cast for the first time, and described presstressed reinforcing steel bundle (6) presents outside radial in the layer of concrete (8) of the described cast first time, and the other end is a pencil; Outside the layer of concrete (8) of the described cast first time, be provided with fluid concrete layer (9) for the second time; The described fluid concrete layer second time (9) is the end of described presstressed reinforcing steel bundle (6), is the presstressed reinforcing steel (2) that separates.

Be respectively equipped with first hole (3), second hole (4) and the 3rd hole (5) on the layer of concrete of presstressed reinforcing steel (2) top in the layer of concrete (8) of described original structure layer of concrete (7), cast for the first time and the fluid concrete layer second time (9).Its objective is in order to find the cut-out point of presstressed reinforcing steel on concrete.

Described presstressed reinforcing steel bundle (6) is to disconnect distributing at the layer of concrete (8) and the fluid concrete layer second time (9) of original structure layer of concrete (7), cast for the first time.Its objective is prestressing force is slowly bled off.

The described fluid concrete layer second time (9) is outer can also to be provided with a layer of concrete to some cast (10), its better effects if.

Described prestressed reinforced concrete construction can obtain by following method: the step before presstressed reinforcing steel 2 on-the-spot cut-outs is set up for the off-load frame, when if the engineering presstressed reinforcing steel mainly is temperature steel, purpose is that structure can not produce big adverse effect to structure because of variations in temperature, in the plate since presstressed reinforcing steel to put a time shorter, and the hole of putting the cutter that picks in the process is also less, so do not need to set up support under the plate.Because beam section is less, to open the hole that picks cutter also less though prestressing force is put, and the useful cross section of beam can reduce, and can the bearing capacity of beam be affected greatly, so need set up reliable support under beam.Presstressed reinforcing steel is provided with for solving crack and amount of deflection in the beam of encorbelmenting, and bigger crack appears in the Liang Zhonghui that may encorbelment after putting, so also need to set up support.That supports sets up the effect that needs to bear deadweight of beam body and working load, supports the support situation that need return to before the former tension of prestressed tendon simultaneously, guarantees in the prestressing force off-load back rest not recurring structure distortion and cracking, the safety of assurance structure.

After finishing the off-load frame and setting up, need to determine the position of prestressed reinforcement 2, support system set up finish after, will be with reference to original structure pre-stress construction drawing, and in conjunction with some detection instruments such as radar survey meter etc., determine the accurate position of prestressed reinforcement and the position of prestressed node, and make a mark, find out presstressed reinforcing steel 2 and prepare for next step picks the cutter concrete.

After the position of prestressed reinforcement 2 is determined, will manually pick cutter and find out prestressed reinforcement 2.Because the lay position to presstressed reinforcing steel 2 is difficult to accurate location in picking the cutter process, so at first by definite radical and position range that needs the presstressed reinforcing steel of processing such as drawing and instrument, and then punch mouthful presstressed reinforcing steel 2 picked according to the size shown in the drawing and dig out apart from beam limit or edges of boards, the plate hole is the square hole hole of 200mm * 200mm, and the hole is deck-siding * 200mm on beam.Must guarantee that presstressed reinforcing steel is without any damage in order to avoid muscle occurs after presstressed reinforcing steel 2 damaged and broken, the anchor head accident such as hurt sb.'s feelings that flies out.So picking when cutter must be earlier with manually bit by bit picking cutter, wait to expose and carry out large tracts of land with electric hammer again behind the presstressed reinforcing steel and pick cutter, and strictness is constructed by construction process.

Pick the selection of the position, hole of punchinging: in prestressed reinforced concrete construction was transformed, picking the hole of punchinging was a bigger workload, and selected suitable position is picked the hole of punchinging and can be reduced a lot of work, reduces and transforms the duration.

Pick the selection of cutter position and mainly follow following principle: presstressed reinforcing steel is nearer from the beam slab face, and needs reservation structure is not had breakage.It is bigger to pick cutter place stirrup spacing, so that manually pick cutter.Generally avoid beam slab end stirrup encrypted area, presstressed reinforcing steel has enough stretch-draw length when guaranteeing to recover prestressing force.

After finding out the prestressed reinforcement position and punching, prestressed reinforcement is carried out temporary fixed and put to open unloading anchor, use extraordinary ground tackle (as opening anchorage, C type ground tackle) to clamp temporarily, adopt different punching and method of temporarily fixing according to different situations.Can adopt the method for gas cutting that the prestressed reinforcement in the hole is cut off then, the prestressing slow release is fallen, must do protection reliably at this tension of prestressed tendon end before blowing, so as to avoid an accident, stretch-draw end presstressed reinforcing steel and ground tackle fly out and hurt sb.'s feelings, and guarantee the people that mustn't stand behind the stretch-draw end in the work progress.Use special equipment such as twin-tub jack with interim ground tackle removal then, finish to put to open and unload the anchor operation.Must be noted that if the place's presstressed reinforcing steel that punches is longer, cut muscle and put Zhang Shihui and produce bigger retraction, security incident occurs, must slowly put and open, strictly undertaken by operational procedure for avoiding putting in the process.

Carry out the concrete excision in specified scope afterwards; after presstressed reinforcing steel 2 off-loads are finished; promptly the transformation position that can punch to needs concrete carries out the large tracts of land excision; in the stretch-draw length range of presstressed reinforcing steel 2, need to keep certain cutter length of picking; pick the cutter process and will note protecting prestressed reinforcement 2, so as to avoid an accident.To guarantee that it has enough stretch-draw active lengths, also will guarantee the anchorage length that it is enough when cutting off presstressed reinforcing steel 2.

Fig. 2 is the presstressed reinforcing steel 2 on-the-spot schematic flow sheets that cut off.Hole place presstressed reinforcing steel 2 cut off put after, also need carry out stretch-draw again, the pre-stressed state in the position peripheral structure that recovers to punch, stretching force carries out according to the prestressed stretching force of original structure.Should be noted that because presstressed reinforcing steel is put and opened and again during stretch-draw, stretch-draw end concrete strength is difficult to satisfy construction requirement and presstressed reinforcing steel and goes out the position, end and be difficult to guarantee perfect condition, therefore before stretch-draw, must carry out consolidation process, to satisfy the requirement of concrete partial pressing to presstressed reinforcing steel 2 ends.Prestressed concrete is transformed, and will need earlier to remove on every prestressed reinforcement 2 positions of member to pick three holes of cutter, and wherein first hole 3 and 5 positions, the 3rd hole are at the edge of the member of intending removing, and is intending in the middle of the member of removing 4 positions, middle hole.After first hole 3, the 3rd hole 5 were picked cutter and finished, the temporary fixed ground tackle 1 of use for tendon at first hole 3,5 places, the 3rd hole was fixed, and adopts hot melt that presstressed reinforcing steel 2 is cut off at 4 places, middle hole.

Fig. 1 is the prestressed reinforced concrete construction schematic diagram.Prestressed reinforcement group bundle 6 in beam arranges that for group's bundle be furnished with many presstressed reinforcing steels 2 in every beam in the original structure concrete seven, in the beam-ends position, this prestressed reinforcement group bundle 6 all is arranged in the upper end of beam.Because the prestressing force stretch-draw processing that prestressed reinforcement 2 need be scatter again, so this just need pour into a mould a part of concrete again and lay bearing plate after concrete removal finishes, and the additional bar of configuration some, to bear the effect of prestressed reinforcement partial pressing.This part concrete strength reaches after 85%, just can be to prestressed reinforcement 2 stretch-draw once more, and control stress for prestressing carries out according to the requirement of original structure.Add ground tackle size and thickness of concrete cover, the concrete eight of cast needs 300mm at least for the first time, and the remainder concrete is fluid concrete 9 for the second time.

By implementing above-mentioned process, in prestressed reinforced concrete construction rebuilding construction process,, guaranteed engineering structures safety and work progress safety in strict accordance with construction technology and rules organizing construction, also obtained good social benefit simultaneously.

Claims

1, a kind of prestressed reinforced concrete construction is characterized in that: comprise original structure layer of concrete (7), be provided with presstressed reinforcing steel bundle (6) in the described original structure layer of concrete (7); Described original structure layer of concrete (7) is provided with the layer of concrete (8) of cast for the first time, and described presstressed reinforcing steel bundle (6) presents outside radial in the layer of concrete (8) of the described cast first time, and the other end is a pencil; Outside the layer of concrete (8) of the described cast first time, be provided with fluid concrete layer (9) for the second time; The end of described presstressed reinforcing steel bundle (6) is for the presstressed reinforcing steel (2) that separates, in the fluid concrete layer second time (9) inside.

2, prestressed reinforced concrete construction according to claim 1 is characterized in that: be respectively equipped with first hole (3), second hole (4) and the 3rd hole (5) on the layer of concrete of the layer of concrete (8) of described original structure layer of concrete (7), cast for the first time and presstressed reinforcing steel (2) top in the fluid concrete layer second time (9).

3, prestressed reinforced concrete construction according to claim 1 and 2 is characterized in that: described presstressed reinforcing steel bundle (6) is to disconnect distributing at the layer of concrete (8) and the fluid concrete layer second time (9) of original structure layer of concrete (7), cast for the first time.

4, prestressed reinforced concrete construction according to claim 1 and 2 is characterized in that: the outer layer of concrete to some cast (10) that is provided with of the described fluid concrete layer second time (9).