CN112392201A

CN112392201A - Square segmental type prestressed ultrahigh-performance concrete pipe combined column

Info

Publication number: CN112392201A
Application number: CN201910762087.9A
Authority: CN
Inventors: 单波; 肖岩; 李天宇
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2019-08-19
Filing date: 2019-08-19
Publication date: 2021-02-23

Abstract

The invention discloses a square sectional type prestressed ultrahigh-performance concrete pipe combined column which comprises ultrahigh-performance concrete pipe sections (1) and prestressed longitudinal ribs (2), wherein the ultrahigh-performance concrete pipe sections (1) are connected through the prestressed longitudinal ribs (2), and filling concrete (3) is poured inside; the method is characterized in that: the ultra-high performance concrete pipe joint (1) is a hollow pipe which is formed by a centrifugal method, is square outside and circular inside, a closed stirrup (4) is arranged inside, a through-long reserved hole channel (5) is arranged at the corner along the direction of a longitudinal axis, and a male connector (6) and a female connector (7) are respectively arranged at two ends of the hollow pipe; the prestressed longitudinal bars (2) penetrate through the reserved pore channels (5) of one or more ultrahigh-performance concrete pipe sections (1), and axial pretightening force is applied to the ultrahigh-performance concrete pipe sections (1) through post-tensioned prestressing force. The invention is suitable for centrifugal production, has convenient length adjustment, meets the requirements of assembly type construction, has the characteristics of high bearing capacity, good durability and the like, and has good application prospect in assembly type buildings and ocean engineering.

Description

Square segmental type prestressed ultrahigh-performance concrete pipe combined column

Technical Field

The invention mainly relates to the field of building structures in civil engineering, in particular to a square sectional type prestressed ultrahigh-performance concrete pipe combined column which can be used as a structural column.

Background

The ultra-high performance concrete (UHPC for short) is a novel cement-based composite material with ultra-high compressive strength, high durability and high toughness. The general compression strength is more than 150MPa, the bending strength can reach 30-60 MPa, the high brittleness of common concrete is effectively overcome, the performance is excellent, the mixing process is similar to that of the common concrete, and the concrete has wide application prospect in civil engineering.

As a high-tech concrete, there are two major factors that currently hinder the large-scale application of UHPC: the first is the higher cost of the unilateral material. The cement and the active admixture of the active powder concrete have large using amount, and simultaneously, a high-efficiency water reducing agent, steel fiber and the like are required to be doped, so the material cost is obviously increased; and the other is that the component needs to be subjected to thermal curing to accelerate the reaction process of the active material and realize rapid improvement of the strength. Therefore, in practical engineering, the application of UHPC takes prefabricated parts as main forms, and the UHPC and other materials form combined parts, so that the ultrahigh pressure resistance of the UHPC is fully exerted, and the material consumption is reduced as much as possible, thereby improving the index of the performance/cost ratio of the UHPC.

The centrifugal method is an efficient mode for producing hollow thin-wall concrete prefabricated parts, and the principle of the centrifugal method is that a pipe die generates huge centrifugal force under high-speed rotation, so that concrete is gathered on the inner wall of the die and a small amount of water is drained, and therefore the concrete pipe with compact texture and uniform thickness is obtained. Practice proves that the method has simple and mature process, does not need an internal mold and has high production efficiency. At present, UHPC pipes produced by a centrifugal method are applied to the power industry, and a combination column for pouring concrete inside the UHPC pipes appears. However, the existing UHPC tube combined column has some defects, firstly, the UHPC tube produced by the centrifugal method is all round tubes, and the formed combined column is a cylinder, but in practical application, a square column is more common, so the application prospect of the combined column based on the UHPC round tube is obviously limited; moreover, for practical buildings, the length of the prefabricated UHPC circular pipe is limited, the prefabricated UHPC circular pipe is often disconnected at a floor position, if longitudinal steel bars are arranged in the pipe wall to resist lateral force (such as earthquake action) born by the building, the longitudinal steel bars are disconnected at the end part of the prefabricated pipe, and the tension of the longitudinal steel bars caused by the lateral force at the upper part cannot be transmitted downwards, so that the longitudinal steel bars cannot be arranged in the pipe wall to resist the lateral force, continuous longitudinal steel bars need to be arranged in filling concrete poured in the prefabricated pipe, and the working procedure of processing and binding longitudinal steel bar cages greatly increases the construction difficulty and the construction period of the combined column; in addition, due to the production equipment, transportation limitation and hoisting requirements, the length of the UHPC prefabricated pipe is limited, so that the length of a single-section prefabricated pipe cannot meet the design requirement possibly for some buildings with high floors or high pier bridges, and the application of the single-section prefabricated pipe is also limited. Therefore, it is desirable to develop a square UHPC tube composite column with adjustable length, which is suitable for centrifugal production.

Disclosure of Invention

The invention aims to provide a square sectional type prestressed ultrahigh-performance concrete pipe combined column which is suitable for centrifugal production, convenient in length adjustment, capable of meeting the requirements of assembly type construction, high in bearing capacity, good in durability and the like.

The solution of the invention is a square sectional type prestressed ultra-high performance concrete pipe combination column, which comprises ultra-high performance concrete pipe sections (1) and prestressed longitudinal ribs (2), wherein the ultra-high performance concrete pipe sections (1) are connected through the prestressed longitudinal ribs (2), and filled concrete (3) is poured inside; the method is characterized in that: the ultra-high performance concrete pipe joint (1) is a hollow pipe which is formed by a centrifugal method, is square outside and circular inside, a closed stirrup (4) is arranged inside, a through-long reserved hole channel (5) is arranged at the corner along the direction of a longitudinal axis, and a male connector (6) and a female connector (7) are respectively arranged at two ends of the hollow pipe; the prestressed longitudinal bars (2) penetrate through the reserved pore channels (5) of one or more ultrahigh-performance concrete pipe sections (1), and axial pretightening force is applied to the ultrahigh-performance concrete pipe sections (1) through post-tensioned prestressing force; grouting materials (8) are poured into the reserved hole channels (5); the stress longitudinal bar (2) and the closed stirrup (4) comprise reinforcing steel bars and fiber reinforced plastic bars; the filling concrete (3) comprises common concrete, light concrete, seawater sea sand concrete and recycled aggregate concrete.

Compared with the prior art, the invention has the advantages that:

the square UHPC pipe section is suitable for centrifugal production. The hollow square section is in an axial symmetry shape, and eccentric force cannot be generated when the hollow square section rotates around the longitudinal axis of the hollow square section, so that the hollow square section is suitable for centrifugal production, the existing centrifugal equipment can be adopted for production only by replacing a square mould with a round mould, and the production is simple and convenient.

Secondly, the length of the combined column is convenient to adjust. Through the adjustment and the combination of UHPC pipe coupling quantity and pipe coupling length, the length of very convenient adjustment combination post satisfies the nonstandard length and the design requirement of overlength post, has broken through prior art's restriction, and greatly reduced the degree of difficulty of links such as prefabricated pipe production, transportation, hoist and mount.

And thirdly, the assembly type construction requirement is met. The UHPC pipe sections are spliced in a butt joint mode, pre-tightening force connection is realized through the longitudinal pre-stressed tendons, and full-assembly construction is realized. In addition, the longitudinal prestressed tendons which are arranged in a full-length mode are used as longitudinal stress tendons of the combined column, so that the tensile force generated by lateral force can be effectively transmitted, the continuous longitudinal stress tendons do not need to be additionally arranged in the internal filling concrete, and the construction is greatly simplified.

And the combined column has high bearing capacity. The UHPC prefabricated pipe has high axial bearing capacity, and the closed stirrups prepared in the prefabricated pipe provide effective lateral constraint stress for the concrete filled in the prefabricated pipe, so that the constrained combined column is formed, and the compressive strength of the concrete in the prefabricated pipe is greatly improved. Therefore, the square sectional type prestressed ultra-high performance concrete pipe combined column effectively combines the UHPC ultra-high strength with the constraint effect of the stirrups, and the combined column has ultra-high pressure-resistant bearing capacity and ductility.

The durability of the combined column is good, and the use and maintenance cost is low. UHPC has high compactness, difficult invasion of external harmful media and outstanding durability. Therefore, the combined column has good corrosion resistance and durability, and is low in use and maintenance cost.

Drawings

FIG. 1 is a schematic cross-sectional structure diagram of a square sectional prestressed ultra-high performance concrete pipe composite column;

FIG. 2 is a schematic structural view of a square sectional type prestressed ultra-high performance concrete pipe composite column in a longitudinal section cut along a longitudinal axis;

fig. 3 is a schematic structural diagram of a square sectional type prestressed ultra-high performance concrete pipe composite column in a longitudinal section cut along a longitudinal prestressed tendon.

Description of the figures

1 is an ultra-high performance concrete pipe section 2 is a prestressed longitudinal bar

3 is filled concrete and 4 is a closed stirrup

5 is a reserved hole passage 6 which is a male connector

7 is a female connector and 8 is grouting material

Detailed Description

As shown in attached

drawings

1, 2 and 3, the square sectional type prestressed ultra-high performance concrete pipe combination column comprises ultra-high performance concrete pipe sections (1) and prestressed longitudinal reinforcements (2), wherein the ultra-high performance concrete pipe sections (1) are connected through the prestressed longitudinal reinforcements (2), and concrete (3) is poured and filled in the square sectional type prestressed ultra-high performance concrete pipe combination column; the method is characterized in that: the ultra-high performance concrete pipe joint (1) is a hollow pipe which is formed by a centrifugal method, is square outside and circular inside, a closed stirrup (4) is arranged inside, a through-long reserved hole channel (5) is arranged at the corner along the direction of a longitudinal axis, and a male connector (6) and a female connector (7) are respectively arranged at two ends of the hollow pipe; the prestressed longitudinal bars (2) penetrate through the reserved pore channels (5) of one or more ultrahigh-performance concrete pipe sections (1), and axial pretightening force is applied to the ultrahigh-performance concrete pipe sections (1) through post-tensioned prestressing force.

When the method is implemented, firstly, a stirrup cage formed by a closed stirrup (4) is bound and placed in a mould of the ultra-high performance concrete pipe joint (1), and the mould is formed by a centrifugal method; the manufactured ultra-high performance concrete pipe joint (1) is placed in hot water at the temperature of 90 ℃ for curing for 48 hours; the prefabricated ultrahigh-performance concrete pipe joint (1) is transported to a construction site to be hoisted and butted in a mode that a male connector (6) is inserted into a female connector (7); penetrating longitudinal prestressed tendons (2) into reserved channels (5) in the ultra-high performance concrete pipe sections (1), tensioning, and applying axial pretightening force to each ultra-high performance concrete pipe section (1); then, pouring filling concrete (3) in the ultra-high performance concrete pipe joint (1); and finally, pouring grouting materials (8) into the reserved hole channel (5) to finish construction.

Claims

1. The square sectional type prestressed ultrahigh-performance concrete pipe combined column comprises ultrahigh-performance concrete pipe sections (1) and prestressed longitudinal ribs (2), wherein the ultrahigh-performance concrete pipe sections (1) are connected through the prestressed longitudinal ribs (2), and concrete (3) is poured and filled in the square sectional type prestressed ultrahigh-performance concrete pipe combined column; the method is characterized in that: the ultra-high performance concrete pipe joint (1) is a hollow pipe which is formed by a centrifugal method, is square outside and circular inside, a closed stirrup (4) is arranged inside, a through-long reserved hole channel (5) is arranged at the corner along the direction of a longitudinal axis, and a male connector (6) and a female connector (7) are respectively arranged at two ends of the hollow pipe; the prestressed longitudinal bars (2) penetrate through the reserved pore channels (5) of one or more ultrahigh-performance concrete pipe sections (1), and axial pretightening force is applied to the ultrahigh-performance concrete pipe sections (1) through post-tensioned prestressing force.

2. The square sectional prestressed ultra-high performance concrete pipe composite column as claimed in claim 1, wherein said reserved hole (5) is filled with grouting material (8).

3. The combined column of the square sectional prestressed ultra-high performance concrete pipe according to claim 1, wherein the prestressed longitudinal ribs (2) and the closed stirrups (4) comprise steel bars and fiber reinforced plastic ribs.

4. The square segmented prestressed ultra-high performance concrete pipe composite column according to claim 1, wherein said filler concrete (3) comprises ordinary concrete, light concrete, seawater sea sand concrete and recycled aggregate concrete.