CN111255159A - A thin-walled steel composite column partially filled with ultra-high toughness cementitious composites - Google Patents

Abstract

The invention discloses a thin-walled steel composite column partially filled with ultra-high toughness cement-based composite material. Two thin-walled flange plates are arranged in parallel, and the middle is connected by a thin-walled web to form an H-shaped structure. The rods are connected, and the ultra-high toughness cement-based composite material is filled between the thin-walled web and the thin-walled flange plate. The ultra-high-toughness cement-based composite material can be wrapped by the thin-walled flange plate and the thin-walled web to form a columnar structure. The invention can overcome the shortcomings of the existing section steel concrete column with excessive self-weight, complex node structure, cumbersome construction process, and need to build a large number of formwork. Filled concrete composite columns.

Description

A thin-walled steel composite column partially filled with ultra-high toughness cementitious composites

technical field

The invention belongs to the technical field of building structures, in particular to a thin-walled steel composite column partially filled with ultra-high toughness cement-based composite materials.

Background technique

At present, steel and concrete composite columns are widely used in construction projects, which have high bearing capacity and good fire resistance. However, the concrete material has low tensile strength, easy cracking, poor ductility, and does not match the deformation capacity of the steel column, which affects the mechanical properties of the composite column. And for the composite column, the section steel is completely filled in the concrete, which causes the composite column to be heavy, complex joints and long construction period.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a thin-walled steel composite column partially filled with ultra-high toughness cement-based composite material in view of the above-mentioned deficiencies in the prior art. .

The present invention adopts following technical scheme:

A thin-walled steel composite column partially filled with ultra-high toughness cement-based composite materials, comprising thin-walled flange plates, two thin-walled flange plates are arranged in parallel, and the middle is connected by a thin-walled web plate to form an H-shaped structure, and the outer edges of the two thin-walled flange plates pass through The tie rod is connected, and the ultra-high-toughness cement-based composite material is filled between the thin-walled web and the thin-walled flange plate. The ultra-high-toughness cement-based composite material can be wrapped by the thin-walled flange plate and the thin-walled web to form a columnar structure.

Specifically, the tie rods are perpendicular to the two thin-walled flange plates, and are arranged parallel to the thin-walled web plates.

Specifically, the tie rods include a plurality of tie rods, which are arranged at equal intervals between the two thin-walled flange plates.

Further, a protective layer with a thickness of 30-50 mm is left between the tie rod and the outer edge of the thin-walled flange plate.

Specifically, the ultra-high toughness cement-based composite material includes cement, fly ash, quartz sand, water reducing agent, water and polyvinyl alcohol fiber, cement: fly ash: quartz sand: water: water reducing agent = 1: 1.5: 1.62:0.9:0.025, the volume ratio of polyvinyl alcohol fiber is 1.5%～2%.

Further, under the condition of room temperature, the cement, fly ash and fine sand are mixed and stirred for 1-2 minutes; the polyvinyl alcohol fibers are added and the stirring is continued for 3-5 minutes until the mixture has no polyvinyl alcohol fibers agglomeration; finally, the water reducing agent is added. Mix it with water and stir well, add it to the mixture and stir for 3-5 minutes to prepare an ultra-high toughness cement-based composite material.

Specifically, the thin-walled flange plate and the thin-walled web plate in the middle are connected by fillet welding.

Further, the cross-sectional shape of the thin-walled steel composite column is square or rectangular.

Compared with the prior art, the present invention at least has the following beneficial effects:

The invention is a thin-walled steel composite column partially filled with ultra-high-toughness cement-based composite material. The ultra-high-toughness cement-based composite material is filled between the thin-wall flange and the thin-walled web, and the thin-wall flange and the thin-walled web can be filled with the material. The formwork saves the formwork; the overall structure is simple, and the thin-walled flange plate is exposed, which is convenient for node connection, convenient for production, and shortens the construction period.

Further, it is formed by welding thin-walled flanges and thin-walled webs of any cross-sectional size. The cross-section of the combined column can be combined according to the engineering conditions, and the cross-sectional form is flexible.

Further, a protective layer of 30-50 mm is left between the tie rod and the outer edge of the thin-walled flange plate to prevent the tie rod from being corroded and failing.

Further, the ultra-high-toughness cement-based composite material exhibits good deformation ability and crack resistance under axial compression and tensile loads, and the ultra-high-toughness cement-based composite material and thin-walled steel columns have good synergistic deformation ability. , which can provide effective support for thin-walled steel columns and improve the overall stability of thin-walled steel columns;

Further, the tie rods welded between the thin-walled flange plates can improve the local buckling capacity of the thin-walled flange plates, and at the same time, the tie-rods, the thin-walled flange plates and the thin-walled web provide restraints on the ultra-high toughness cement-based composite materials, so that the material properties can be obtained. fully use.

Further, the cross-sectional shape of the column is set to be square or rectangular, which can facilitate the connection between the column and the beam and facilitate construction.

To sum up, the present invention can overcome the shortcomings of the existing profiled steel concrete column with excessive self-weight, complex joint structure, cumbersome construction process, and need to build a large number of formwork, and is excellent in cost, steel content, cross-section flexibility, crack resistance, and deformation capacity. Fill the existing section with concrete composite columns.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

1 is a schematic cross-sectional view of the present invention;

Fig. 2 is a three-dimensional schematic diagram of the present invention;

Figure 3 is a schematic diagram of the pouring surface of the present invention.

Among them: 1. Thin-walled flange plate; 2. Thin-walled web; 3. Tie rod; 4. Ultra-high toughness cement-based composite material.

Detailed ways

In the description of the present invention, it should be understood that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left", "right", " The orientation or positional relationship indicated by "vertical", "horizontal", "top", "bottom", "inside", "outside", "one side", "one end", "one side", etc. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Also, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Ultra-high toughness cement-based composite materials, based on micromechanical principles, improve the fiber, matrix and the interface between the two in cement-based composite materials. By adding high-performance polyvinyl alcohol fibers, the tensile strength of traditional concrete materials is greatly improved. The ductility and brittle fracture properties have the characteristics of high deformation ability, crack resistance and good ductility; and the ultra-high toughness cement-based composite material and thin-walled steel column have good cooperative deformation ability.

1 and 2, a thin-walled steel composite column partially filled with ultra-high toughness cement-based composite material of the present invention includes thin-wall flange plate 1, thin-walled web plate 2, tie rods 3 and ultra-high toughness cement-based composite material 4 .

The two thin-walled flange plates 1 are arranged in parallel, and the middle is connected by the thin-walled web 2 to form an H-shaped structure. After molding, the ultra-high-toughness cement-based composite material 4 is filled in the blank areas formed by the thin-walled flange plates 1 at both ends and the middle thin-walled web plate 2 respectively. There are two parts in total. The composite material 4 cannot be completely filled, which is called partial filling. The ultra-high toughness cement-based composite material is wrapped on three sides by the thin-walled flange plate 1 and the thin-walled web plate 2 to form a columnar structure.

The thin-walled flange plate 1 and the thin-walled web plate 2 are hot-rolled thin-walled steel plates of the same material.

The thin-walled flange plates 1 at both ends of the steel composite column and the thin-walled web plate 2 in the middle are connected by fillet welding.

The tie rods 3 are arranged between the two thin-walled flange plates 1 at intervals, and the arrangement is perpendicular to the thin-walled flange plates 1 and parallel to the thin-walled web plate 2 .

The section shape of the thin-walled steel composite column is square or rectangular.

Ultra-high toughness cement-based composite material 4 includes cement, fly ash, quartz sand, naphthalene-based superplasticizer, water and polyvinyl alcohol fiber, in terms of mass percentage, cement: fly ash: quartz sand: water: water reducing Agent=1:1.5:1.62:0.9:0.025, and the volume ratio of polyvinyl alcohol fibers is 1.5% to 2%.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example

Please refer to FIG. 3 , a thin-walled steel composite column partially filled with ultra-high toughness cement-based composite material of the present invention, the thin-walled steel composite column is a square column with a side length of 450mm and a column height of 3.0m; the tie rod 3 is a steel rod with a diameter of 14mm, And arranged at a distance of 450mm; thin-walled flange plate 1 and thin-walled web plate 2 are both Q345 grade steel with a thickness of 6mm, and thin-walled flange plate 1 and thin-walled web plate 2 are welded into H-shape, and thin-walled flange plate 1 and thin-walled web plate 2 are welded into H shape. The ultra-high toughness cement-based composite material 4 is filled between the wall webs 2 .

The specific construction process is as follows:

S1. The thin-walled flange plate 1 and the thin-walled web plate 2 are welded by electrode arc welding and fillet welding to form an H-shaped thin-walled steel column;

S2. Arrange the tie rods 3 on the inner side of the thin-walled flange plate 1 at a fixed distance. The method used is to position and perforate the thin-walled flange plate 1 first, and then insert the tie rods 3 into the flange positioning holes. double-sided spot welding;

S3. There is a protective layer thickness of 30-50mm between the tie rod 3 and the outer edge of the thin-walled flange plate 1;

S4, pouring the ultra-high toughness cement-based composite material 4, filling the space between the thin-walled flange plate 1 and the thin-walled web plate 2, and mechanically planing both ends of the composite column after the natural curing is completed to obtain the part filled with ultra-high toughness cement Thin-walled steel composite columns of matrix composites.

A vertical forced mixer is used in the production of ultra-high toughness cement-based composite materials. The mixing sequence is as follows: first weigh cement, fly ash, fine sand, water reducing agent and water; The fine sand is mixed and stirred for 1-2 minutes; the polyvinyl alcohol fibers are added manually and stirred for 3-5 minutes, until the mixture has no agglomeration of the polyvinyl alcohol fibers; finally, the water reducing agent is mixed into the water, stirred well, and added to the mixture Stir for 3 to 5 minutes, and the production process is complete.

The tensile and compressive performance tests of ultra-high toughness cement-based materials and their results are as follows:

(1) Prepare a 70.7mm×70.7mm×210mm prismatic test block for axial compression test. The test results show that the average compressive strength of the test block is 74.0Mpa. Due to the existence of polyvinyl alcohol fibers, the compressive deformation ability of the test block is enhanced, and the ultimate compressive strain reaches 0.01, while the ultimate compressive strain of ordinary concrete test block is only 0.003 to 0.004. The test block prepared from the ultra-high-toughness cement-based material can maintain good integrity during the whole loading process, and has no brittle failure characteristics similar to ordinary concrete, and has good compressive toughness.

(2) Prepare a 330mm×60mm×13mm dog-bone test block for axial tension test. During the test, the test block has multiple fine cracks, the crack width is 0.05~0.1mm, the tensile strength is 4.5Mpa, and the ultimate tensile strain It is 2.0% to 2.5%, showing excellent tensile toughness. In comparison, the ultimate tensile strain of ordinary concrete is extremely small, which can be ignored. The tensile failure of ultra-high toughness cement-based materials is obviously different from that of ordinary concrete.

The ultra-high toughness cement-based composite material improves the fiber, matrix and the interface between the two in the cement-based composite material based on the micromechanical principle. When it is damaged, it shows multi-crack cracking, and does not appear the spalling phenomenon of ordinary concrete. It has good resistance. Compression and tensile toughness.

The ultra-high toughness cement-based composite material improves the fiber, matrix and the interface between the two in the cement-based composite material based on the principle of micromechanics. When it is damaged, it shows multi-crack cracking without the spalling phenomenon of traditional concrete. It has good resistance. Compression and tensile toughness.

The ultra-high toughness cement-based composite material has good deformation ability, and has a good cooperative deformation ability with the thin-walled steel column. Filling the material between the thin-walled flange plate and the thin-walled web can improve the overall stability of the thin-walled steel column. At the same time, by filling the ultra-high toughness cement-based composite material, the exposed area of the thin-walled steel plate can be reduced, the corrosion rate of the thin-walled steel plate can be effectively reduced, the service life of the composite column can be increased, and the fire resistance of the composite column can be improved.

In terms of construction, the construction template required for pouring is reduced, the construction is convenient, and the social and economic benefits are relatively good.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (8)

1. The utility model provides a thin wall steel combination column of part packing ultra high tenacity cement based composite, a serial communication port, including thin wall flange board (1), two thin wall flange boards (1) parallel arrangement, the centre is connected through thin wall web (2) and is constituted H type structure, the outward flange of two thin wall flange boards (1) passes through tie rod (3) to be connected, fill ultra high tenacity cement based composite (4) between thin wall web (2) and thin wall flange board (1), ultra high tenacity cement based composite can be wrapped up by thin wall flange board (1) and thin wall web (2) and form the column structure.

2. The thin-walled steel composite column partially filled with an ultra-high toughness cement-based composite material according to claim 1, wherein the tie rods (3) are arranged perpendicular to the two thin-walled flange plates (1) and parallel to the thin-walled web (2).

3. The thin-walled steel composite column partially filled with an ultra-high toughness cement-based composite material according to claim 1, wherein the tie rod (3) comprises a plurality of tie rods, which are arranged at equal intervals between the two thin-walled flange plates (1).

4. The thin-walled steel composite column partially filled with the ultra-high toughness cement-based composite material as claimed in claim 3, wherein the tie bars (3) leave a protective layer with a thickness of 30-50 mm from the outer edge of the thin-walled flange plate (1).

5. The thin-walled steel composite column partially filled with an ultra-high toughness cement-based composite material according to claim 1, wherein the ultra-high toughness cement-based composite material (4) comprises cement, fly ash, quartz sand, a water reducing agent, water and polyvinyl alcohol fiber, the cement: fly ash: quartz sand: water: 1 of water reducing agent: 1.5: 1.62: 0.9: 0.025, and the volume ratio of the polyvinyl alcohol fiber is 1.5-2%.

6. The thin-walled steel composite column partially filled with the ultra-high toughness cement-based composite material according to claim 5, wherein the cement, the fly ash and the fine sand are mixed and stirred for 1-2 min at room temperature; adding polyvinyl alcohol fibers, and continuously stirring for 3-5 min until the mixture has no polyvinyl alcohol fiber agglomeration phenomenon; and finally, adding the water reducing agent into water, stirring uniformly, adding the mixture into the mixture, and stirring for 3-5 min to prepare the ultra-high-toughness cement-based composite material.

7. The thin-walled steel composite column partially filled with an ultra-high toughness cement-based composite material according to claim 1, wherein the thin-walled flange plate (1) and the thin-walled web plate (2) in the middle are connected by fillet welding.

8. The thin-walled steel composite column partially filled with an ultra-high toughness cement-based composite material according to any one of claims 1 to 7, wherein the thin-walled steel composite column has a square or rectangular cross-sectional shape.

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