CN215716556U

CN215716556U - Novel prefabricated UHPC-NC superposed beam

Info

Publication number: CN215716556U
Application number: CN202120420162.6U
Authority: CN
Inventors: 李志杰
Original assignee: Xinjiang University
Current assignee: Xinjiang University
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2022-02-01
Anticipated expiration: 2031-02-24

Abstract

The utility model discloses a novel prefabricated UHPC-NC superposed beam, which comprises: the prefabricated part of composite beam, combination semi-closed stirrup and cast-in-place concrete lamination layer. The prefabricated part is Ultra-High Performance Concrete (UHPC), and the cast-in-place Concrete is Normal Concrete (NC). The cross section of the superposed beam is rectangular or T-shaped, wherein a bottle-shaped groove is formed in the prefabricated part; pouring common cast-in-place concrete to fill the inner bottle-shaped groove and form a whole with the laminated layer poured on the top of the prefabricated part of the laminated beam; the combined semi-closed stirrup consists of a U-shaped opening stirrup arranged in the prefabricated part of the superposed beam and a stirrup cap arranged in cast-in-place concrete. The UHPC has high tensile strength and good crack resistance, and the bottle-shaped groove can effectively restrain common concrete, improve the bonding property of the superposed surface and improve the bearing capacity of the structure. The novel prefabricated UHPC-NC superposed beam provided by the utility model has the advantages of good integrity, excellent anti-seismic performance, high comprehensive economic benefit, energy conservation and environmental protection, and conforms to the national green development concept.

Description

Novel prefabricated UHPC-NC superposed beam

Technical Field

The utility model belongs to the technical field of civil engineering, and particularly relates to a novel prefabricated UHPC-NC superposed beam.

Background

Compared with a cast-in-place construction mode, the fabricated concrete structure meets the requirements of land conservation, energy conservation, material conservation, water conservation, environmental protection and the like of green construction, reduces negative effects on the environment, including noise reduction, dust prevention, environmental pollution reduction, clean transportation, site interference reduction and resource conservation.

The superposed beam is a beam which is cast and tamped with concrete twice, the precast beam is made in a precast yard for the first time and is carried out in a construction site for the second time, and after the precast beam is hoisted and placed, the concrete at the upper part is cast and tamped to connect the precast beam and the precast beam into a whole. At present, most of materials of the concrete superposed beams used at home and abroad are common concrete, the superposed beams have good economic benefit and convenient construction, but the member integrity is poorer than that of the integral cast-in-place beam.

The utility model provides a novel prefabricated UHPC-NC superposed beam, wherein the lower prefabricated part is made of UHPC, and the upper cast-in-place part is made of common concrete. Compared with common concrete, the tensile strength of the UHPC cannot be ignored, and the UHPC is adopted at the lower part of the superposed beam, so that the bending resistance bearing capacity of the beam can be obviously improved; the UHPC has high strength, steel fibers are doped in the UHPC, and when cracks appear, the tensile action of the steel fibers can effectively inhibit the development of the cracks, so that the ductility of a component is enhanced, and the span of a beam is increased; be equipped with the recess in the prefabricated part, can protect inside ordinary concrete, improve structural durability. Experiments show that the shear strength of the superposed surface of the common concrete and the ultrahigh-performance concrete is far higher than that of the superposed surface of the common concrete superposed beam.

Disclosure of Invention

The utility model aims to provide a superposed beam which has the advantages of high bearing capacity, reasonable stress, convenient construction and good integrity and seismic performance.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides a novel prefabricated UHPC-NC superposed beam, which comprises a superposed beam prefabricated part (1), cast-in-place concrete (2) and a combined semi-closed stirrup (3), wherein the integral cross section of the superposed beam is rectangular or T-shaped; a bottle-shaped groove (4) formed in the prefabricated part (1) of the superposed beam; the cast-in-place concrete (2) is formed into a whole by filling a bottle-shaped groove (4) in the precast composite beam part (1) and a superposed layer poured on the top of the precast composite beam part (1) by casting common cast-in-place concrete; the combined semi-closed stirrup (3) is composed of a U-shaped open stirrup (5) which is provided with a superposed beam in the prefabricated part (1) and a stirrup cap (6) which is arranged in cast-in-place concrete (2), and the U-shaped open stirrup and the stirrup cap are mutually overlapped.

The prefabricated part (1) of the composite beam is made of UHPC, and the cast-in-place concrete (2) is made of ordinary concrete.

The bottle-shaped groove (4) in the prefabricated part (1) of the superposed beam: the upper part is inverted splayed, the middle rectangular inner groove (8) and the lower splayed inner groove (9) form a tooth shape, the extending length is 15-20mm, and the wall thickness of the bottom rectangular inner groove (10) is 50 mm.

The top of the prefabricated part (1) of the superposed beam and the bottle-shaped groove (4) inside the prefabricated part are both contact surfaces with cast-in-place concrete (2) and should be made into rough surfaces with the concave-convex difference not less than 4 mm.

The utility model has the advantages that:

1. the utility model reduces the dead weight of the prefabricated part to a certain extent;

2. the utility model can reduce manual work and field construction work;

3. the utility model realizes the industrialized production, and is convenient and fast;

4. the utility model can effectively combine the advantages of common concrete and UHPC, and realize the maximization of the strength under the condition of controlling the cost. And the integrity is good, and the seismic performance is excellent.

Drawings

The utility model will be further described with reference to the accompanying drawings in which:

fig. 1 is a schematic front view of a prefabricated UHPC-NC composite beam according to the present invention.

Fig. 2 is a schematic cross-sectional view of the prefabricated UHPC-NC composite beam according to the present invention.

Fig. 3 is a schematic view of the bottle-shaped groove (4) inside the prefabricated UHPC-NC composite beam according to the utility model.

Fig. 4 is a schematic diagram of the overlapping of the prefabricated UHPC-NC superposed beam combined stirrup of the utility model.

Reference numbers in the figures: 1-prefabricated part of a superposed beam, 2-cast-in-place concrete, 3-combined stirrups, 4-bottle-shaped grooves, 5-U-shaped open stirrups, 6-stirrup caps, 7-inverted splayed holes, 8-rectangular inner grooves, 9-splayed inner grooves and 10-rectangular inner grooves.

Detailed Description

As shown in the front view of fig. 1, a novel prefabricated UHPC-NC composite beam comprises the following components: the composite beam comprises a prefabricated part (1) of a composite beam, cast-in-place concrete (2) and a combined semi-closed stirrup (3).

Fig. 3 is a schematic diagram of bottle-shaped grooves (4) in a prefabricated UHPC-NC composite beam, wherein the bottle-shaped grooves (4) are formed in a prefabricated part (1) of the composite beam and are divided into four parts: the upper part is an inverted splayed opening (7), the middle part is a rectangular inner groove (8), the lower part is a splayed inner groove (9), the bottom part is a rectangular inner groove (10), and the overall section of the splayed inner groove is a bottle-shaped groove (4).

The manufacturing method of the novel prefabricated UHPC-NC superposed beam comprises the following manufacturing steps:

the method comprises the following steps: pouring the prefabricated part (1) of the superposed beam, the U-shaped opening stirrup (5) and the bottle-shaped groove (4) in a prefabricated part factory, and maintaining the prefabricated part to the designed strength;

step two: transporting the superposed beam prefabricated part (1) to a construction site, and hoisting the superposed beam prefabricated part in place;

step three: the longitudinal bars at the top of the beam are firmly bound with the U-shaped opening stirrups (5), and finally, the stirrup caps (6) are bound on the U-shaped opening stirrups (5) to form combined semi-closed stirrups (3);

step four: a template is arranged on the outer side of the prefabricated part (1) of the superposed beam, common concrete is used for pouring the cast-in-place concrete (2) of the superposed beam, and the superposed beam is closely vibrated during pouring;

step five: and removing the die and maintaining to form the UHPC-NC superposed beam.

The foregoing is an exemplary embodiment of the present invention, and the practice of the present invention is not limited thereto.

Claims

1. The utility model provides a novel prefabricated UHPC-NC superposed beam which characterized in that: the composite beam comprises a composite beam prefabricated part (1), cast-in-place concrete (2) and a combined semi-closed stirrup (3), wherein the cross section of the composite beam is rectangular or T-shaped, and a bottle-shaped groove (4) is formed in the composite beam prefabricated part (1); the cast-in-place concrete (2) is formed into a whole by filling a bottle-shaped groove (4) in the precast composite beam part (1) and a superposed layer poured on the top of the precast composite beam part (1) by casting common cast-in-place concrete; the combined semi-closed stirrup (3) is composed of a U-shaped open stirrup (5) which is provided with a superposed beam in the prefabricated part (1) and a stirrup cap (6) which is arranged in cast-in-place concrete (2), and the U-shaped open stirrup and the stirrup cap are mutually overlapped.

2. The novel prefabricated UHPC-NC composite beam of claim 1, characterized in that: the material of the prefabricated part (1) of the superposed beam is UHPC; the cast-in-place concrete (2) is made of common concrete, and the outer surface of the cast-in-place concrete is flush with the outer surface of the prefabricated part (1) of the composite beam.

3. The novel prefabricated UHPC-NC composite beam of claim 1, characterized in that: the bottle-shaped groove (4) in the prefabricated part (1) of the superposed beam, the inverted-splayed hole (7) in the upper part, the middle rectangular inner groove (8) and the lower splayed inner groove (9) form a pair of teeth, the extending length is 15-20mm, and the wall thickness of the bottom rectangular inner groove (10) is 50 mm.

4. The novel prefabricated UHPC-NC composite beam of claim 1, characterized in that: u-shaped opening stirrups (5) are arranged inside the prefabricated part (1) of the superposed beam, the prefabricated part (1) of the superposed beam extends upwards from two sides of the prefabricated part of the superposed beam, and the length of the prefabricated part of the superposed beam extending out of the U-shaped opening stirrups (5) is more than 10 times of the diameter of the prefabricated beam.

5. The novel prefabricated UHPC-NC composite beam of claim 1, characterized in that: the top of the prefabricated part (1) of the superposed beam and the bottle-shaped groove (4) are both contact surfaces with cast-in-place concrete (2) and should be made into rough surfaces with the concave-convex difference not less than 4 mm.