CN2784490Y

CN2784490Y - Prestress connection node for beam column of assembled concrete frame structure

Info

Publication number: CN2784490Y
Application number: CN 200520017140
Authority: CN
Inventors: 马华; 李振宝; 董挺峰; 白聪敏
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2005-04-22
Filing date: 2005-04-22
Publication date: 2006-05-31
Anticipated expiration: 2015-04-22

Abstract

The utility model relates to a prestressing force connection node for beams and posts of assembled concrete frame structures, which belongs to the technical field of precast assembly type concrete structures in civil engineering. The utility model aims at overcoming the defects of a normal concrete structure that damage controlling design is difficult to realize, and cast-in-place connection nodes of precast units need cast-in-place concrete. The utility model is characterized in that beams (1) and posts (2) are all precast, gaps with the width no more than 10 mm are arranged between the beams and the posts, and the gaps are closed by mortar (3); a pore canal (4) is arranged in the position of upper and lower core points of the cross section of the beams (1) and on the posts (2) corresponding to the upper and the lower core points of the cross section of the beams, so that a non-adhesive prestressing force rib (5) can penetrate into the pore canal (4); the range between the upper and the lower parts at the end of the beams is respectively provided with two spiral steel reinforcement confined concrete (6) overlaping with each other, and the height of the range is no more than one half of the height of the posts to the surface of the posts. The utility model creates conditions for realizing the damage controlling design of the structure, and is favorable to the realization of strong nodes, or can reduce the configuration quantity of hoop reinforcements of nodes by adopting the identical design prestressing force.

Description

The prestressing force connected node of assembly concrete frame construction beam column

Technical field

The prestressing force connected node of assembly concrete frame construction beam column is used for prefabricated beam column concrete component is assembled into framework integral body, belongs to prefabricated assembled concrete technical field of structures in the civil engineering.

Background technology

Along with the development of society, the function of building becomes increasingly complex, and other loss that earthquake brings may be more much bigger than the loss that building itself destroys.And at present for macroseism, the final goal of structure design is to avoid the life security of building collapsing with the protection people, also is difficult to realize to control the economy that macroseism causes and the damage control design of loss function.This difficulty is said from structure and mainly is following three aspects: the ordinary concrete structure relies on member to absorb and the dissipation seismic energy, so member is ftractureed and damages by pressure unavoidable; Reinforcement stresses surpasses yield stress, is difficult to accurate calculating; Tend to occur bigger permanent set.Therefore, how to address these problems, significant to the ACTIVE CONTROL level that improves the loss that people cause earthquake disaster.

On the other hand, reduce that situ wet workload, easily assurance of component quality, good endurance, simplification support works, speed of application are fast, economical with materials, help advantages such as industrialization of construction industry, economy and social environment benefit are good, because prefabricated concrete structure is compared with cast-in-place concrete structure to have so should actively apply prefabricated concrete structure.Yet the anti-seismic performance of fabricated construction is determined by the connection between the prefabricated units.The most of area of China is in the district that provides fortification against earthquakes, so connect the whether reliable application that directly influences fabricated construction.First assembled formula concrete structure relies on substantially and is welded to connect, and, in Tangshan Earthquake in 1976, fabricated construction destroys serious, almost all collapses.Henceforth, be to improve the anti-seismic performance of fabricated construction, require the connected node of fabricated construction can be similar with cast-in-place node.Generally adopted the assembly structure form of the cast-in-place nodes of prefabricated units for this reason.This connected node is that the reinforcing bar that stretches out in the prefabricated beam and column is coupled together by welding or overlap joint at the node place, reproduces and waters the concrete at node place, thereby form the cast-in-situ steel reinforced concrete node.Although the globality of this form of structure and anti-seismic performance can compare favourably with cast-in-place structural, but because this connected node needs cast-in-situ concrete, thereby having weakened prefabricated concrete structure short construction period, good in economic efficiency advantage greatly, this makes the development of fabricated construction and application be subjected to having a strong impact on.Therefore eliminate cast-in-situ concrete, the advantage of giving full play to prefabricated concrete structure seems very necessary.

In view of above reason, we are by having researched and proposed the prestressing force connected node of assembly concrete frame construction beam column.

The utility model content

The utility model is difficult to realize damage control design at the ordinary concrete structure, and the cast-in-place connected node of prefabricated units needs the shortcoming of cast-in-situ concrete, provides a kind of novel connected node, to address the above problem.

The structure of the prestressing force connected node of assembly concrete frame construction beam column is as shown in Figure 1: beam 1 and post 2 are prefabricated, leave between beam 1 and the post 2 to be not more than the wide slit of 10mm, by mortar 3 sealings; The core point position is stayed and is established duct 4 so that penetrate unbonded prestressing tendon 5 about the corresponding beam section on upper and lower core point of beam section and post; The beam-ends upper and lower part is not less than apart from the post surface and adopts two spiral reinforcement 6 confined concretes of overlap joint mutually in the 1/2 deck-molding scope respectively.

The upper and lower core point in described beam 1 cross section is on the vertical axis, cross section respectively apart from last lower limb 1/3 depth of section place for the square-section.

Described spiral reinforcement 6 is that the beam-ends concrete damages by pressure too early and disposes when preventing that earthquake from causing large deformation repeatedly; Configuration amount is by being no less than 2% of its confined concrete volume, and pitch is not more than 1/4 of screw diameter, and screw diameter should be between 1/2 deck-siding and 1/3 deck-molding; Requiring of its concrete cover minimum thickness and stirrup is identical.

The design principles of the prestressing force size of unbonded prestressing tendon is: should guarantee the friction shear resisting ability of junction, the stress in the presstressed reinforcing steel is remained in the yield limit.

The configuration amount of unbonded prestressing tendon is determined according to connecting section design anti-bending bearing capacity in this connected node.The internal diameter in duct 4 should be than the diameter of unbonded prestressing tendon big 6～15mm.

In this connected node, beam column produces pressure and frictional force by means of the prestressing force of unbonded prestressing tendon at beam column contact surface place, and the beam column member is assembled into framework integral body.The shearing of beam passes to post by the frictional force between the Liang Yuzhu, therefore all bracket need be set in beam and column.Unbonded prestressing tendon is when providing junction moment of flexure bearing capacity, and build-up pressure between the beam column contact surface also so that the junction has enough friction shear resisting abilities, passes to post with the shearing of beam.By the initial stress of suitable design unbonded prestressing tendon, the stress in the unbonded prestressing tendon is remained in the elastic range, even behind the earthquake displacement of big earthquake intensity, also can between beam column, keep compressive pre-stress.This rigidity that keeps when being connected normal service load and little shake, when meeting with the earthquake of big earthquake intensity, beam column contact surface place becomes hinge and rotates, thus the dissipative part energy.Be aided with energy-dissipating device dissipative part seismic energy in case of necessity again.Because unbonded prestressing tendon keeps elasticity, the permanent set of structure after shake is very little, can ignore and not remember.This is resolved with regard to making existing aforementioned three problems of ordinary concrete structure, has created condition thereby control design for the damage of implementation structure.In addition, owing to adopt unbonded prestressing tendon, during the stirrup of configuration and ordinary reinforced concrete structure equivalent, the stress of stirrup reduces, and helps realizing strong node in node area and beam; Can reduce the stirrup configuration amount of node when perhaps adopting identical design stress.

Description of drawings

Fig. 1 is the prestressing force connected node front elevation view of assembly concrete frame construction beam column;

Fig. 2 is for being beam-ends sectional view (the A-A cross section of Fig. 1);

Fig. 3 is a girder span middle part sectional view (the B-B cross section of Fig. 1).

Among the figure: the 1st, beam, the 2nd, post, the 3rd, mortar, the 4th, duct, the 5th, unbonded prestressing tendon, the 6th, spiral reinforcement.

Attention: for making clear other arrangement of reinforcement of beam column that do not draw of drawing, other arrangement of reinforcement should be determined by design.

The specific embodiment

For realizing the prestressing force connected node of assembly concrete frame construction beam column, at first according to precast beam 1 and posts 2 such as the definite sectional dimension of design, quantity of reinforcement, strength grade of concrete, beam and column is precast reinforced concrete structure, also can be the precast prestressed concrete member.At the fixing spiral reinforcement 6 of beam-ends, adopt pre-buried bellows or steel pipe to stay and establish duct 4 when prefabricated, the duct lays respectively at the position of core point up and down of beam section; Same pre-buried bellows of assigned position or steel pipe stay and establish duct 4 in post; Should adopt unpolished wooden form to make matsurface to increase frictional force at the contact surface place of beam column.The beam and column concrete curing can be transported and on-site hoisting after design strength.The lifting post lifts beam more earlier, and beam can support by interim bracket is installed on post.After post, beam are in place, in reserving hole channel 4, penetrate unbonded prestressing tendon 5.Unbonded prestressing tendon should adopt the non-bending steel cable (f of extruding plastic-coated _Ptk=1860N/mm ²).Penetrate the slit perfusion mortar 3 between beam column behind the unbonded prestressing tendon, and the mortar in perfusion duct 4.The used mortar in slit between the beam column should be with fibre mortar or epoxy mortar, and fiber should be used nylon fiber, the desirable 10～15mm of its length, and volume can be by every cubic metre of mortar 1.5～2kg.The duct gets final product with the ordinary mortar perfusion.Mortar available water mud replaces, and requires the design compressive strength of mortar or cement paste to be not less than beam concrete design compressive strength.Grouting reaches design strength post tensioning unbonded prestressing tendon and uses the ground tackle anchoring.Remove interim support at last, promptly form desired connected node.

Claims

1, the prestressing force connected node of assembly concrete frame construction beam column is characterized in that: beam (1) and post (2) are prefabricated, leave between the Liang Yuzhu and are not more than the wide slit of 10mm, seal by mortar (3); At the upper and lower core point in beam (1) cross section, and post (2) is gone up corresponding beam section and is stayed and establish duct (4) so that penetrate unbonded prestressing tendon (5) in the core point position up and down; The beam-ends upper and lower part is not less than apart from the post surface and adopts two spiral reinforcement (6) confined concretes of overlap joint mutually in the 1/2 deck-molding scope respectively.

2, the prestressing force connected node of assembly concrete frame construction beam column according to claim 1, the upper and lower core point in described beam (1) cross section is on the vertical axis, cross section respectively apart from last lower limb 1/3 depth of section place for the square-section.

3, the prestressing force connected node of assembly concrete frame construction beam column according to claim 1, described spiral reinforcement (6) configuration amount is by being no less than 2% of its confined concrete volume, and pitch is not more than 1/4 of screw diameter, and screw diameter should be between 1/2 deck-siding and 1/3 deck-molding; Requiring of its concrete cover minimum thickness and stirrup is identical.