CN217105822U - Hollow sandwich steel pipe sea sand concrete combined column constrained by multiple CFRP (circulating fluidized bed reactor) - Google Patents

Abstract

The invention relates to a multi-CFRP (carbon fiber reinforced plastics) constrained hollow sandwich steel pipe sea sand concrete combination column, which comprises a plastic inner pipe and a common carbon steel outer pipe which are coaxially arranged from inside to outside, wherein the inner wall and the outer wall of the common carbon steel outer pipe are respectively provided with at least one layer of CFRP cloth, the outer wall of the plastic inner pipe is provided with at least one layer of CFRP cloth, sea sand concrete is filled between the plastic inner pipe and the common carbon steel outer pipe, the combination column adopts the plastic inner pipe to have little influence on the bearing capacity of the structure, can also reduce the quality of the structure, has light dead weight, can fully utilize sea sand resources under the condition of preventing corrosion while meeting the mechanical requirement of the structure in the actual engineering, reduces the excavation and use of river sand, and saves great engineering cost.

Description

Hollow sandwich steel pipe sea sand concrete combined column constrained by multiple CFRP (circulating fluidized bed reactor)

Technical Field

The invention relates to a hollow sandwich steel pipe and sea sand concrete combined column constrained by multiple CFRP.

Background

With the continuous promotion of the infrastructure of China, the demand of building materials is increased day by day. According to the incomplete statistics of the Chinese concrete net, the total yield of commercial concrete in China in 2019 is 27.38 billion cubic meters, and the yield is increased by 7.51 percent on a par. Meanwhile, the demand of the building sand used as concrete fine aggregate is continuously increased, and the annual building sand consumption of China reaches 26 hundred million tons according to statistics. At present, river sand is a main source of building sand in China, and because the natural resources of the river sand are limited and the regeneration speed is slow, the river sand is difficult to meet the rapidly-increased building development scale in China. In recent years, a series of problems of serious river sand shortage, river bed reduction, peripheral ecological environment damage and the like caused by river sand over-exploitation and disorderly excavation by illegal manufacturers also cause serious economic loss to the nation, the society and people. The building sand has large gaps, the contradiction between the supply and the demand of the sand is increasingly prominent, and river sand resources face the danger of exhaustion, so that other sand sources are urgently needed to solve the problem of river sand shortage.

Sea sand has its unique advantage compared with river sand: low mud content, uniform fineness modulus, low price and the like. How to reasonably develop and utilize sea sand resources to replace river sand, relieving the supply and demand contradiction between the resource limitation of the river sand and the increase of urban development demand, and especially in the southeast coastal areas with relatively large sand amount for buildings, the method has important significance for energy conservation, emission reduction and ecological environment protection.

Compared with natural river sand, the main reasons for limiting the application of sea sand to building engineering are the high content of chlorine salt and shells and light substances. The chloride in the sea sand can influence the hydration process of the portland cement, particularly has corrosion action on concrete steel bars, can cause the corrosion problem of the steel bars in a concrete structure, and seriously influences the service life of the structure; light materials such as seashells affect the workability, strength, durability, etc. of concrete. There are also many cases of "sea sand houses" caused by the improper use of sea sand concrete in recent years.

Disclosure of Invention

Aiming at the defects, the invention provides the hollow sandwich steel pipe and sea sand concrete combined column with multiple CFRP constraints.

The technical scheme for solving the technical problem is that the multi-CFRP-constrained hollow sandwich steel tube sea sand concrete combination column comprises a plastic inner tube and a common carbon steel outer tube which are coaxially arranged from inside to outside, wherein at least one layer of CFRP cloth is arranged on the inner wall and the outer wall of the common carbon steel outer tube, at least one layer of CFRP cloth is arranged on the outer wall of the plastic inner tube, and sea sand concrete is filled between the plastic inner tube and the common carbon steel outer tube.

Furthermore, the plastic inner pipe is a round pipe or a square pipe.

Furthermore, the common carbon steel outer pipe is a round pipe or a square pipe.

Furthermore, the CFRP cloth is adhered to the outer wall of the plastic inner pipe or the inner wall and the outer wall of the common carbon steel outer pipe through resin adhesive.

Further, the plastic inner pipe is a PVC pipe, a PPR pipe or an FRP pipe.

Further, the plain carbon steel outer pipe is made of carbon steel.

Compared with the prior art, the invention has the following beneficial effects: the self-weight is light, the mechanical requirements of the structure in actual engineering are met, sea sand resources can be fully utilized under the corrosion prevention condition, the excavation and the use of river sand are reduced, and great engineering cost is saved.

Drawings

The invention is further described with reference to the following figures.

FIG. 1 is a schematic diagram of a first embodiment of an integrated column.

FIG. 2 is a schematic diagram of a second embodiment of the integrated column.

FIG. 3 is a schematic view of a third embodiment of the integrated column.

FIG. 4 is a schematic diagram of a fourth embodiment of the integrated column.

Fig. 5 is a first structural diagram of the base mold.

Fig. 6 is a second schematic view of the base mold structure.

In the figure: 1-ordinary carbon steel pipe; 2-sea sand concrete; 3-plastic inner tube; 4-CFRP cloth; and 5-reinforcing steel bars.

Detailed Description

The technical solution 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.

As shown in fig. 1-4, a multiple CFRP-constrained hollow sandwich steel tube sea sand concrete composite column comprises a plastic inner tube 3 and a common carbon steel outer tube 1 which are coaxially arranged from inside to outside, wherein the inner wall and the outer wall of the common carbon steel outer tube are both provided with at least one layer of CFRP cloth 4, the outer wall of the plastic inner tube is provided with at least one layer of CFRP cloth, sea sand concrete 5 is filled between the plastic inner tube and the common carbon steel outer tube, the CFRP cloth on the inner wall of the common carbon steel outer tube can prevent harmful substances in the sea sand concrete from corroding the outer steel tube, and the plastic inner tube, the common carbon steel and the CFRP cloth constrain core concrete together, so that the bearing capacity, ductility and durability of the whole structure are improved; under the condition of the same size and thickness, the price of CFRP + common carbon steel is only about 50% of that of stainless steel, so that the structural form has better economy; the plastic inner pipe can be used as a water supply pipe, a drain pipe, an industrial anti-corrosion pipe and the like while reducing the self weight of the combined column, and the structure can be used in an oil or gas pipeline, so that the application range of the steel pipe concrete is expanded; in the construction process, the plastic inner pipe can also be used as a template for pouring concrete, so that the template cost is saved, the template does not need to be disassembled, the construction procedures are reduced, and the construction efficiency is improved; the CFRP cloth on the circumferential side wall of the plastic inner pipe can well restrict the deformation of the plastic inner pipe and prevent the plastic inner pipe from brittle failure, and meanwhile, the plastic inner pipe with the CFRP cloth adhered on the outer wall can also restrict the deformation and crack development of core concrete, so that the bearing capacity of the structure is indirectly improved, but the load is not directly borne.

In this embodiment, the sea sand concrete is prepared by uniformly stirring and pouring ordinary undisturbed sea sand, ordinary well-graded stones, ordinary tap water, fresh water or seawater and ordinary cement in a set proportion. The application of the sea sand in the concrete has the following advantages: the price is 3/5 of the price of river sand with the same quality; the mud content is low, which is beneficial to improving the mechanical property of the concrete; the sorting is good, the distribution is centralized, and the transportation is convenient; the particles are uniformly distributed, and the crushing index is small.

In this embodiment, the plastic inner tube is a circular tube or a square tube.

In this embodiment, the outer tube of plain carbon steel is a round tube or a square tube.

In this embodiment, the CFRP cloth is attached to the outer wall of the plastic inner pipe or the inner and outer walls of the plain carbon steel outer pipe by resin adhesive.

In this embodiment, the plastic inner pipe is a PVC pipe, a PPR pipe, or an FRP pipe.

In the embodiment, the outer tube of the plain carbon steel is carbon steel, such as Q235, Q345 carbon steel.

The construction of the combined column comprises the following steps:

1. pasting CFRP cloth on the outer wall of the pipe:

(1) calculating the length and width of the CFRP cloth according to the number of layers of the CFRP cloth and the sizes of the outer steel pipe and the plastic inner pipe, and cutting for later use;

(2) before winding CFRP cloth, polishing and derusting the outer wall of the steel pipe by using abrasive paper, stopping polishing when the steel pipe is silvery white, and wiping the outer wall of the steel pipe by using alcohol cotton soaked by alcohol until dirt on the outer wall of the steel pipe is wiped completely, and meanwhile, wiping the outer wall of the plastic inner pipe completely by using alcohol;

(3) the CFRP impregnating glue is prepared according to the following steps of A: b =2:1, and stirring at low speed until the color is uniform;

(4) uniformly coating impregnating glue on the front side and the back side of the cut CFRP cloth, repeatedly lightly coating and pressing by using a scraping plate to fully impregnate the CFRP cloth, and coating a layer of glue on the outer wall; then fixing one end of the CFRP cloth to enable the CFRP cloth to be tightly attached to the outer wall of the steel pipe or the plastic inner pipe, rolling the steel pipe or the plastic inner pipe to enable the CFRP cloth to be wound and attached, and meanwhile, slowly smoothing and extruding along the winding direction by using a scraper to remove air bubbles;

(5) and (4) after the impregnating adhesive is completely cured.

2. Pasting CFRP cloth on the inner wall of the pipe:

(1) calculating the length and width of the CFRP cloth according to the number of layers of the CFRP cloth and the size of the steel pipe, and cutting for later use;

(2) before winding CFRP cloth, polishing and derusting the inner wall of the steel pipe by using abrasive paper, stopping polishing when the steel pipe is silvery white, and wiping the inner wall of the steel pipe by using alcohol cotton soaked by alcohol until dirt on the inner wall of the steel pipe is wiped completely;

(3) the CFRP impregnating glue is prepared according to the following steps of A: b =2:1, and stirring at low speed until the color is uniform;

(4) uniformly coating impregnating glue on the front side and the back side of the cut CFRP cloth, repeatedly lightly coating and pressing by using a scraping plate to fully impregnate the CFRP cloth, and coating a layer of glue on the inner wall; then, putting the fresh-keeping film on a prepared transparent fresh-keeping film, one surface of which is coated with lubricating oil and the size of which is slightly larger than that of the CFRP cloth to be placed, wherein the surface of the fresh-keeping film, which is in contact with the CFRP cloth, is not coated with the lubricating oil; finally, wrapping one side of the preservative film, which is coated with lubricating oil, on a tubular rubber air mold with the diameter slightly smaller than the inner diameter of the steel pipe, and ensuring a certain lap joint length;

(5) and after the impregnating adhesive is completely cured, deflating the air mould and detaching the air mould.

3. Pouring interlayer sea sand concrete:

4. firstly, manufacturing a base mold according to the size of a component pasted with CFRP cloth, respectively welding four reinforcing steel bars 5 according to the inner diameter of an inner pipe and the outer diameter of an outer pipe, wherein the specific style is shown in figures 5 and 6, and the inner pipe and the outer pipe are fixed without deviation when the base mold is used for pouring; then, preventing concrete from entering the inner pipe during pouring, and wrapping one end of the inner pipe which is poured by plastic cloth; finally, ordinary undisturbed sea sand, ordinary stones with good gradation, ordinary tap water fresh water or seawater and ordinary cement are graded and stirred into concrete according to a certain proportion, the concrete is poured into the middle of an interlayer of the steel pipe, the member is placed on a vibration table to vibrate until the concrete in the steel pipe is poured compactly, and the top of the concrete is slightly higher than the upper end face of the steel pipe.

5. Polishing and maintaining:

6. and after the concrete is poured, covering geotextile on the surface of the test piece, watering and curing at regular intervals, and after the test piece is cured for 28 days, grinding redundant concrete and redundant CFRP (carbon fiber reinforced plastics) cloth at the end part to be flush with the end surface of the steel pipe by using an angle grinder, so that the core concrete and the steel pipe can be stressed together as soon as loading is ensured as possible.

If this patent discloses or refers to parts or structures that are fixedly connected to each other, the fixedly connected may be understood as: a detachable fixed connection (for example using bolts or screws) is also understood as: non-detachable fixed connections (e.g. riveting, welding), but of course, fixed connections to each other may also be replaced by one-piece structures (e.g. manufactured integrally using a casting process) (unless it is obviously impossible to use an integral forming process).

In the description of this patent, it is to be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the patent, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.

The above-mentioned preferred embodiments, further illustrating the objects, technical solutions and advantages of the present invention, should be understood that the above-mentioned are only preferred embodiments of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. The utility model provides a cavity intermediate layer steel pipe sea sand concrete combination column of multiple CFRP restraint which characterized in that: the sea sand concrete composite pipe comprises a plastic inner pipe and a common carbon steel outer pipe which are coaxially arranged from inside to outside, wherein the inner wall and the outer wall of the common carbon steel outer pipe are both provided with at least one layer of CFRP cloth, the outer wall of the plastic inner pipe is provided with at least one layer of CFRP cloth, and sea sand concrete is filled between the plastic inner pipe and the common carbon steel outer pipe.

2. The multiple CFRP confined hollow sandwich steel pipe sea concrete composite column of claim 1, wherein: the plastic inner pipe is a round pipe or a square pipe.

3. The multiple CFRP confined hollow sandwich steel pipe sea concrete composite column of claim 2, wherein: the common carbon steel outer pipe is a round pipe or a square pipe.

4. The multiple CFRP confined hollow sandwich steel pipe sea concrete composite column of claim 1, wherein: the CFRP cloth is adhered to the outer wall of the plastic inner pipe or the inner wall and the outer wall of the common carbon steel outer pipe through resin adhesive.

5. The multiple CFRP confined hollow sandwich steel pipe sea concrete composite column of claim 1, wherein: the plastic inner pipe is a PVC pipe, a PPR pipe or an FRP pipe.

6. The multiple CFRP confined hollow sandwich steel pipe sea concrete composite column of claim 1, wherein: the common carbon steel outer pipe is made of carbon steel.

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