CN108360748A - A kind of composite steel tube UHPC damping stubs - Google Patents

Abstract

The invention relates to the technical field of civil engineering, in particular to a composite steel pipe UHPC shock-absorbing pier. The composite steel pipe UHPC damping pier of the present invention is composed of an outer steel pipe, an inner steel pipe, a UHPC layer and a rubber concrete layer; the inner steel pipe is sleeved inside the outer steel pipe; the UHPC layer is filled in the inner wall of the outer steel pipe Between the outer wall of the inner steel pipe; the rubber concrete layer is filled inside the inner steel pipe. The present invention makes full use of the advantages of steel pipe, UHPC and rubber concrete, better solves the anti-corrosion problem of steel pipe concrete, improves the durability of the component, reduces the cost of the whole life cycle of the component, and prolongs the life cycle of the component; at the same time, the composite column Energy saving and environmental protection, in line with the concept of green building and the requirements of sustainable development of the construction industry; and the component has a large bearing capacity reserve, good ductility, superior seismic performance, fatigue resistance and impact resistance, good damping performance, excellent seismic performance and good shock absorbing capacity.

Description

A composite steel pipe UHPC shock-absorbing pier

technical field

The invention relates to the technical field of civil engineering, in particular to a composite steel pipe UHPC shock-absorbing pier.

Background technique

my country is one of the countries that produce the largest amount of waste rubber tires, and its consumption of rubber resources ranks among the top in the world. According to relevant data predictions, by 2020, the generation of waste rubber in my country will reach more than 6 million tons. Waste rubber is not easy to degrade, and it will pollute the environment after landfill, and incineration will bring air pollution. Simultaneously, if waste rubber can not be rationally utilized, it will also cause a waste of effective energy. The disposal of waste rubber and how to reasonably solve the resource utilization of waste rubber have become urgent problems to be solved.

Rubber aggregate concrete is a new type of green environmental protection building material made by mixing rubber particles into cement concrete mixture. Current research at home and abroad shows that the physical and chemical properties of rubber particles are relatively stable, and the surface is rough. Noise performance, impact resistance, toughness and shock isolation energy dissipation capacity have become an effective way to deal with rubber waste. Rubber concrete has been widely used in roads, bridges, housing construction and other projects at home and abroad.

Ultra-High Performance Concrete (UHPC for short), including reactive powder concrete (Reactive Powder Concrete, RPC for short), due to its different preparation and components, its mechanical properties and deformation ability are significantly better than ordinary concrete , high-strength concrete and high-performance concrete. Its preparation principles include removing coarse aggregates based on the theory of maximum compactness, increasing the fineness and activity of components, etc., so as to minimize internal defects of the material; adding steel fibers to increase toughness; using high-efficiency water reducers to reduce water rubber ratio and porosity etc. UHPC is a kind of material with extremely high compressive strength (its compressive strength is usually between 100-300MPa), flexural strength, high toughness, high durability, high crack resistance, ultra-high impermeability and good durability. Green new ultra-high-strength concrete with abrasive properties, high ductility and tensile strength has broad application prospects in municipal, housing construction, nuclear power, marine and other engineering and military facilities, but it is inherently brittle with its ultra-high strength Limit its application in civil engineering.

Concrete-filled steel tube (CFST) structures can make up for each other's strengths, complement each other, and work together. With its advantages such as small cross-sectional size, high rigidity, strong compressive capacity, good seismic performance, and convenient and quick construction, it has become a widely used in housing construction and bridge engineering. One of the structural forms. However, regular and strict anti-corrosion treatment is required for ordinary concrete-filled steel pipe concrete during service, otherwise it is prone to corrosion, which will affect the mechanical properties and durability of the overall component, increase the maintenance cost and cost of the entire life cycle of the structure, and limit the use of this type of component in special environments. Applications.

Columns are important load-bearing components in building structures, and their seismic performance plays a vital role in the safety of building construction and the protection of people's lives and property.

At present, the earthquake resistance of buildings mainly depends on the strength and stiffness of structural components, resulting in excessive structure weight, resulting in excessive use of building materials, resulting in resource constraints, high project costs, and to a certain extent, affecting the appearance and function of buildings. The practice of resisting earthquakes by increasing the rigidity and strength of the structure does not meet the requirements of sustainable development of the construction industry.

Based on this, it is necessary to develop a group of composite steel pipe UHPC shock-absorbing column piers with good shock resistance and shock absorption performance.

Contents of the invention

The technical problem to be solved by the present invention is to provide a composite steel pipe UHPC shock-absorbing column pier, which effectively overcomes the defects of the prior art.

The technical scheme of the present invention to solve the above-mentioned technical problems is as follows: a kind of composite steel pipe UHPC damping pier, is made up of outer steel pipe, inner steel pipe, UHPC layer and rubber concrete layer;

The above-mentioned inner steel pipe is sleeved inside the above-mentioned outer steel pipe;

The UHPC layer is filled between the inner wall of the outer steel pipe and the outer wall of the inner steel pipe;

The rubber concrete layer is filled inside the inner steel pipe.

The beneficial effects of the present invention are: making full use of the advantages of steel pipe, UHPC and rubber concrete, better solving the anticorrosion problem of steel pipe concrete, improving the durability of components, reducing the cost of the whole life cycle of components, and prolonging the life cycle of components ; At the same time, the composite column is energy-saving and environmentally friendly, which meets the requirements of the green building concept and the sustainable development of the construction industry; and the component has a large bearing capacity reserve, good ductility, superior seismic performance, fatigue resistance and impact resistance, and good damping performance. Excellent shock resistance and good shock absorption capacity.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the above-mentioned outer steel pipe is a stainless steel pipe, and the above-mentioned inner steel pipe is a carbon steel pipe.

The beneficial effect of adopting the above further scheme is that the outer steel pipe has strong corrosion resistance, the outer steel pipe can resist acid and alkali long-term corrosion, the service life of the pipe is long, and the inner steel pipe adopts carbon steel pipe to save engineering construction cost.

Further, the cross-section of the above-mentioned outer steel pipe and/or inner steel pipe is circular or polygonal, and the centerlines of the two coincide.

The beneficial effect of adopting the above-mentioned further scheme is that the cross-sectional shape of the outer steel pipe and the inner steel pipe can be arbitrarily selected according to the actual situation.

Further, the diameter or side length of the above-mentioned outer steel pipe is not less than 200mm, and the thickness is not less than 3mm; the diameter or side length of the above-mentioned inner steel pipe is not less than 80mm, and the thickness is not less than 2mm.

The beneficial effect of adopting the above further scheme is that its shape is diversified, and it can ensure that the inner and outer steel pipes provide appropriate constraints on the concrete in the pipe, so as to meet the strength and ductility requirements of the specimen.

Further, the vertical distance between the inner wall of the outer steel pipe and the outer wall of the inner steel pipe at any corresponding position is not less than 50mm.

The beneficial effect of adopting the above further scheme is that the structure of the entire pier is relatively reasonable, which is convenient for pouring and vibrating the UHPC between the pipes, and is beneficial to ensure the construction quality of the UHPC.

Further, the diameter of the above-mentioned outer steel pipe or the side length of any side of the cross-section is greater than 1000mm, and the inner wall of the above-mentioned outer steel pipe is evenly spaced with a plurality of pegs for strengthening the bonding performance with the UHPC layer.

The beneficial effect of adopting the above further solution is that the bonding performance between the outer steel pipe and UHPC can be enhanced, and at the same time, the local buckling of the outer steel pipe can be delayed, and the interaction between the outer steel pipe and UHPC can be improved.

Further, the vertical distance between the inner wall of the outer steel pipe and the outer wall of the inner steel pipe at any corresponding position is greater than 500mm, and the inner wall of the outer steel pipe and the outer wall of the inner steel pipe are evenly spaced along the direction of the center line of the two. Multiple supporting partitions, both ends of each supporting partition are connected and fixed to the inner wall of the outer steel pipe and the outer wall of the inner steel pipe.

The beneficial effect of adopting the above-mentioned further solution is that the integrity of the outer steel pipe and the inner steel pipe can be strengthened, and the composite pipes can be synchronously and cooperatively operated.

Further, the above-mentioned rubber concrete layer is made by mixing the following materials in parts by weight:

The beneficial effect of adopting the above-mentioned further scheme is that the rubber concrete layer has a good energy-absorbing effect, and improves the energy dissipation and shock-absorbing performance of the whole pier.

Furthermore, the above-mentioned water reducer is a polycarboxylate water reducer, and its water reducing rate is greater than or equal to 25%.

The beneficial effect of adopting the above-mentioned further scheme is that it has good compatibility with various cements, good slump retention performance of concrete, and prolongs the construction time of concrete; low dosage, high water-reducing rate, and small shrinkage; greatly improves the concrete's slump retention performance. Early and late strength; low chloride ion content and low alkali content are beneficial to the durability of concrete; the production process is pollution-free and does not contain formaldehyde, which meets the international standard of ISO14000 environmental protection management; polycarboxylate water reducing agent can be used more More slag or fly ash to replace cement, thereby reducing costs.

Furthermore, the particle size of the above-mentioned rubber particles or rubber powder is 0-3 mm.

The beneficial effect of adopting the above further scheme is that the particle size is moderate, which is conducive to the uniform dispersion of rubber particles or rubber powder in the concrete matrix, reducing the weak surface at the interface with the matrix, and ensuring that the overall pier has better structural strength and shock absorption. performance.

Description of drawings

Fig. 1 is the cross-sectional structure schematic diagram of composite steel pipe UHPC damping pier of the present invention;

Fig. 2 is the cross-sectional structure schematic diagram of some embodiments of composite steel pipe UHPC shock-absorbing pier of the present invention;

Fig. 3 is a cross-sectional structural schematic diagram of other embodiments of the composite steel pipe UHPC shock-absorbing pier of the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Outer steel pipe, 2. Inner steel pipe, 3. UHPC layer, 4. Rubber concrete layer, 5. Studs, 6. Supporting partition.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and examples are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Embodiment: As shown in Figure 1, the composite steel pipe UHPC shock-absorbing pier of this embodiment is composed of an outer steel pipe 1, an inner steel pipe 2, a UHPC layer 3 and a rubber concrete layer 4;

The above-mentioned 2 inner steel pipes are set inside the above-mentioned outer steel pipe 1;

The UHPC layer 3 is filled between the inner wall of the outer steel pipe 1 and the outer wall of the inner steel pipe 2;

The rubber concrete layer 4 is filled inside the inner steel pipe 2 .

The inner steel pipe 2 of the entire composite steel pipe UHPC shock-absorbing pier can provide constraints on the rubber concrete layer 4, which can improve the bonding performance between rubber and concrete, and enhance the shock isolation and energy dissipation capacity of the rubber concrete layer 4; Provides strong constraints, overcomes the brittleness of UHPC layer 3, can make full use of the strength of outer steel pipe 1 and UHPC layer 3, reduces the section size of the entire pier member, increases the buildable height and span of the building, and reduces the maintenance of composite steel pipes during service Expenses, expanding the scope of application of composite steel pipe concrete.

Compared with the prior art, the present invention has the following advantages:

1) The outer steel pipe can effectively restrain the UHPC layer 3, not only can make full use of the high-strength properties of the UHPC layer 3 to effectively overcome the brittleness of the UHPC layer 3, but also make full use of its own strength and ductility;

2) The application of the high-durability green UHPC layer 3 can reduce the amount of concrete, protect the environment, save resources, and meet the sustainable development needs of the construction industry. The high strength of the UHPC layer 3 is conducive to reducing the cross-sectional size of the column pier member and reducing the structural weight;

3) The internal rubber concrete 4 has a good energy dissipation and shock absorption effect, can effectively absorb part of the earthquake energy, and improve the seismic performance of the column pier components, which is conducive to meeting the requirements of various performance levels;

4) The entire composite steel pipe UHPC shock-absorbing column pier has high bearing capacity, residual bearing capacity and ductility performance, which can increase the structural height and span, facilitate structural layout, and increase the usable space of the building.

Preferably, the above-mentioned outer steel pipe 1 is a stainless steel pipe, the above-mentioned inner steel pipe 2 is a carbon steel pipe, and the stainless steel outer steel pipe 1 can reduce and avoid the rust and corrosion prevention problems of the steel pipe during service, reduce the maintenance cost during the service period of the project, and save the whole life Cycle costs, expanding the scope of use of concrete filled steel pipe structures, so that they can be used in some special environments (humid, acidic, etc.).

Preferably, the cross-section of the outer steel pipe 1 and/or the inner steel pipe 2 is circular or polygonal, and the centerlines of the two coincide. During construction, steel pipes with different cross-sectional shapes can be arbitrarily selected according to the construction requirements on site. Higher, so that the final pier structure meets the requirements of architectural modeling and structural stress.

Preferably, the diameter or side length of the above-mentioned outer steel pipe 1 is not less than 200mm, and the thickness is not less than 3mm; the diameter or side length of the above-mentioned inner steel pipe 2 is not less than 80mm, and the thickness is not less than 2mm. To match the engineering requirements, the inner and outer steel pipes provide appropriate constraints on the concrete inside the pipes to meet the strength and ductility requirements of the specimens.

Preferably, when the cross-section of the outer steel pipe 1 and/or the inner steel pipe 2 is circular, the ratio of its diameter to its thickness is not greater than 150, or when the cross-section of the outer steel pipe 1 and/or the inner steel pipe 2 is polygonal , the ratio of the length of any side of its cross-section to its thickness is not greater than 60.

Preferably, the vertical distance between the inner wall of the above-mentioned outer steel pipe 1 and the outer wall of the above-mentioned inner steel pipe 2 at any corresponding position is not less than 50mm, and the distance between the inner and outer pipes in this design is moderate, ensuring the structural strength of the entire pier Match actual engineering performance requirements.

Preferably, the diameter of the above-mentioned outer steel pipe 1 or the length of any side of the cross-section is greater than 1000 mm, and the inner wall of the above-mentioned outer steel pipe 1 is evenly spaced with a plurality of pegs 5 for strengthening the bonding performance with the UHPC layer 3 , the stud 5 is buried in the UHPC layer 3 during the construction process, which can strengthen the bonding performance between the outer steel pipe and the UHPC layer 3, and at the same time play a supporting role to a certain extent for the outer steel pipe 1, prevent its local buckling, and improve the outer steel pipe. Interaction with UHPC layer 3.

Preferably, the vertical distance between the inner wall of the outer steel pipe 1 and the outer wall of the inner steel pipe 2 at any corresponding position is greater than 500 mm, and the distance between the inner wall of the outer steel pipe 1 and the outer wall of the inner steel pipe 2 is along the centerline of the two. A plurality of support partitions 6 are arranged at uniform intervals in the direction to improve the overall performance or cooperative performance (including strength, ductility and toughness, etc.) of the shock-absorbing pier. The inner wall of the steel pipe 1 is connected and fixed to the outer wall of the above-mentioned inner steel pipe 2. This design is based on a pier structure with a larger size. The integrity of the outer steel pipe 1 and the inner steel pipe 2 can be strengthened through a plurality of uniformly distributed support partitions 6 to ensure the composite Tubes work together synchronously.

In some embodiments, the above-mentioned rubber concrete layer 4 is made by mixing the following materials in parts by weight:

In other embodiments, the above-mentioned rubber concrete layer 4 is made by mixing the following materials in parts by weight:

In some other embodiments, the above-mentioned rubber concrete layer 4 is made by mixing materials of the following parts by weight:

The above-mentioned water reducer is a polycarboxylate water reducer, its water reducing rate is greater than or equal to 25%, its versatility is strong, its compatibility with various cements is good, and the slump retention performance of concrete is good; and in the preparation of rubber Concrete 4 has low content, high water-reducing rate, and small shrinkage; greatly improves the early and late strength of concrete; low chloride ion content and low alkali content are beneficial to the durability of concrete; the production process is pollution-free and does not contain formaldehyde; In addition, with the use of polycarboxylate water reducers, more slag or fly ash can be used to replace cement, thereby reducing costs.

Preferably, the particle size of the above-mentioned rubber particles or rubber powder is 0-3 mm, and its size is moderate, which is conducive to the uniform dispersion of rubber particles or rubber powder in the concrete matrix, reducing the weak surface at the interface with the matrix, high structural strength, shock resistance, Good shock absorption performance.

The above-mentioned rubber granules or rubber powder can be used as waste rubber, which can effectively recycle waste rubber, help save energy, protect the ecological environment, and meet the strategic goal of sustainable development.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. A composite steel pipe UHPC shock-absorbing column pier is characterized in that: it is composed of an outer steel pipe (1), an inner steel pipe (2), a UHPC layer (3) and a rubber concrete layer (4); The inner steel pipe (2) is sheathed inside the outer steel pipe (1); The UHPC layer (3) is filled between the inner wall of the outer steel pipe (1) and the outer wall of the inner steel pipe (2); The rubber concrete layer (4) is filled inside the inner steel pipe (2). 2. A composite steel pipe UHPC shock-absorbing pier according to claim 1, characterized in that: the outer steel pipe (1) is a stainless steel pipe, and the inner steel pipe (2) is a carbon steel pipe. 3. A kind of composite steel pipe UHPC shock-absorbing pier according to claim 2, characterized in that: the cross-section of the outer steel pipe (1) and/or the inner steel pipe (2) is circular or polygonal, and both centerlines coincide. 4. A kind of composite steel pipe UHPC damping pier according to claim 3, characterized in that: the diameter or side length of the outer steel pipe (1) is not less than 200mm, and the thickness is not less than 3mm; the inner steel pipe (2 ) diameter or side length is not less than 80mm, and the thickness is not less than 2mm. 5. A composite steel pipe UHPC shock-absorbing column pier according to claim 3 or 4, characterized in that: the inner wall of the outer steel pipe (1) and the outer wall of the inner steel pipe (2) are at any corresponding position The vertical distance between them is not less than 50mm. 6. A composite steel pipe UHPC shock-absorbing pier according to claim 5, characterized in that: the diameter of the outer steel pipe (1) or the side length of any side of the cross section is greater than 1000mm, and the outer steel pipe (1) A plurality of pegs (5) for strengthening the bonding performance with the UHPC layer (3) are evenly spaced on the inner wall. 7. A kind of composite steel pipe UHPC shock-absorbing pier according to claim 6, characterized in that: the inner wall of the outer steel pipe (1) and the outer wall of the inner steel pipe (2) at any corresponding position The vertical distance is greater than 500 mm, and the inner wall of the outer steel pipe (1) and the outer wall of the inner steel pipe (2) are evenly spaced along the direction of the center line of the two, and a plurality of support partitions (6) are arranged, each of the Both ends of the supporting partition (6) are connected and fixed to the inner wall of the outer steel pipe (1) and the outer wall of the inner steel pipe (2). 8. A composite steel pipe UHPC shock-absorbing column pier according to any one of claims 1 to 4, wherein the rubber concrete layer (4) is made by mixing the following materials in parts by weight: 9. A composite steel pipe UHPC shock-absorbing column pier according to claim 8, characterized in that: the water reducing agent is a polycarboxylate water reducing agent, and its water reducing rate is greater than or equal to 25%. 10. A composite steel pipe UHPC shock-absorbing column pier according to claim 8, characterized in that: the particle size of the rubber particles or rubber powder is 0-3 mm.