Corrosion-resistant concrete composite column and preparation device thereof

Abstract

The utility model belongs to the technical field of concrete structures, and provides a corrosion-resistant concrete composite column and a preparation device thereof, the corrosion-resistant concrete composite column comprises a common concrete column body and a hollow magnesium phosphate concrete column body covering the outer side of the common concrete column body, the height of the magnesium phosphate concrete column body is consistent with that of the common concrete column body, and the magnesium phosphate concrete column body is arranged in the common concrete column body. And the size of the magnesium phosphate concrete column body except the height is equal-proportion amplification of the size of a common concrete column body. And the thickness of the magnesium phosphate concrete column body is reduced, so that the production cost of the whole composite column is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of concrete structures, and in particular relates to a corrosion-resistant concrete composite column and a preparation device thereof. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Concrete is the most widely used and largest amount of structural material. The reinforced concrete structure formed by combining with steel bars is also the most widely used structural form, generally also called concrete structure. Compared with other structural materials such as steel, wood and plastic, reinforced concrete structural materials have the characteristics of high temperature resistance, corrosion resistance, fire resistance and aging resistance, and also have the characteristics of wide material sources and relatively low prices. Therefore, concrete structure has been a very important structural form since its birth, because of its excellent durability. Under normal environmental conditions, the service life of concrete can reach decades or even hundreds of years.

[0004] Among concrete structures, columns are an extremely common structural form and the most important structural form. Many important structures are inseparable from column structures. Usually, column structures need to contact soil and water environments, and many of these environments are severely corrosive, such as saline-alkali land, salt lakes and marine environments. This places very high demands on the durability of concrete column structures. The current practice is to protect the concrete column by coating a protective layer on the surface of the concrete column after the concrete is formed and hardened, so as to improve the corrosion resistance of the concrete column. However, the protection of concrete columns through secondary construction is not only complicated in process, but also increases costs to a certain extent. In particular, the degree of bonding between the protective layer and the concrete is limited, so the protective effect is limited.

[0005] There are many ways to improve the corrosion resistance of concrete itself, but the effect is very limited for ordinary concrete. Therefore, there is also a practice of using new cementitious materials instead of ordinary Portland cement. Among them, magnesium phosphate concrete has the most effective corrosion resistance. Magnesium phosphate concrete uses magnesium phosphate cementitious material (also known as magnesium phosphate cement) as a cementitious material, and a certain amount of graded sand, stone aggregate and admixtures are mixed in a certain proportion, and finally water is added. After stirring and forming, it can quickly solidify to form an artificial stone with a certain mechanical strength. Magnesium phosphate concrete has strong corrosion resistance. However, magnesium phosphate concrete is relatively expensive and difficult to use in large areas or large volumes. Utility Model Content

[0006] In order to solve the above problems, the utility model proposes a corrosion-resistant concrete composite column and a preparation device thereof. By covering a hollow magnesium phosphate concrete column on the outside of an ordinary concrete column, the thickness of the magnesium phosphate concrete column is reduced, and the production cost of the overall composite column can be reduced.

[0007] According to some embodiments, the utility model adopts the following technical solutions:

[0008] In the first aspect, a corrosion-resistant concrete composite column is proposed, comprising an ordinary concrete column and a hollow magnesium phosphate concrete column wrapped around the outside of the ordinary concrete column, wherein the height of the magnesium phosphate concrete column is consistent with the height of the ordinary concrete column, and the dimensions of the magnesium phosphate concrete column other than the height are proportionally enlarged to the dimensions of the ordinary concrete column.

[0009] Furthermore, the magnesium phosphate concrete column has a uniform thickness.

[0010] Furthermore, the ordinary concrete column and the magnesium phosphate concrete column are both cubes, and the side length of the ordinary concrete column is smaller than the side length of the magnesium phosphate concrete column.

[0011] Furthermore, the ordinary concrete column and the magnesium phosphate concrete column are both cylinders, and the outer diameter of the ordinary concrete column is equal to the inner diameter of the magnesium phosphate concrete column.

[0012] Furthermore, a plurality of steel bars are arranged in the ordinary concrete column.

[0013] In a second aspect, a preparation device for a corrosion-resistant concrete composite column is provided. The corrosion-resistant concrete composite column adopts the corrosion-resistant concrete composite column described in the first aspect. The preparation device includes an inner mold for pouring ordinary concrete and an outer mold for pouring magnesium phosphate concrete.

[0014] The inner mold is arranged inside the outer mold, and the central axes of the inner mold and the outer mold are located on a straight line.

[0015] Furthermore, a plurality of evenly distributed connecting rods are arranged on the top of the inner mold, a first end of each connecting rod is fixedly connected to the top of the inner mold, and a limiting block is fixedly arranged on the second end of each connecting rod;

[0016] The connecting rod is a telescopic rod and is provided with a scale.

[0017] Furthermore, the height of the outer mold is smaller than the height of the inner mold.

[0018] Furthermore, the inner mold is an integrated structure.

[0019] Furthermore, the inner mold and the outer mold are both bottomless and hollow cylinders, and the radius of the inner mold is smaller than the radius of the outer mold. The radius difference between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column, and the radius of the inner mold is the radius of an ordinary concrete column.

[0020] Furthermore, the inner mold and the outer mold are both bottomless and hollow cubes, and the side length of the inner mold is smaller than the side length of the outer mold. Half of the difference in side length between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column, and the side length of the inner mold is the side length of an ordinary concrete column.

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] The utility model provides a corrosion-resistant concrete composite column, which reduces the thickness of the magnesium phosphate concrete column by covering the hollow magnesium phosphate concrete column outside the ordinary concrete column, and can reduce the production cost of the overall composite column.

[0023] The utility model provides a corrosion-resistant concrete composite column, the interior of which is an ordinary concrete column body, and the exterior of which is a hollow magnesium phosphate concrete column body with excellent corrosion resistance. It is resistant to sulfate and chloride corrosion and can be used in seawater environments, salt lake environments, saline-alkali lands, and soil environments with extremely high sulfate content.

[0024] The utility model provides a preparation device for a corrosion-resistant concrete composite column. Through an inner mold and an outer mold, different concretes can be poured simultaneously. The integrated design of the inner mold can realize the lifting of the inner mold after the magnesium phosphate cement concrete solidifies and before the ordinary concrete inside solidifies, so that the magnesium phosphate concrete as a concrete protective layer is seamlessly combined with the ordinary concrete.

[0025] The utility model provides a preparation device for a corrosion-resistant concrete composite column. Through the arrangement of a connecting rod and a limit block, the central axes of an inner mold and an outer mold can be made consistent, and the uniformity of the thickness of a magnesium phosphate concrete column can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0027] Figure 1 This is a schematic diagram of the overall structure of a corrosion-resistant concrete composite column of the utility model;

[0028] Figure 2 It is a side view of the inner mold of the utility model;

[0029] Figure 3 This is a top view of the inner mold of the utility model which is a cylinder;

[0030] Figure 4 This is a top view of the inner mold of the utility model which is a cube;

[0031] Figure 5 It is a top view of the semicircular plate of the utility model;

[0032] Figure 6 It is a top view of the square plate of the present invention. DETAILED DESCRIPTION

[0033] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the term "comprising" is used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] In the present invention, terms such as "upper", "vertical", "horizontal", "upward", "downward" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention.

[0037] In the present invention, terms such as "fixed" and "fixed" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they cannot be understood as limiting the present invention.

[0038] Terminology explanation:

[0039] Ordinary concrete: An artificial stone made by mixing cement as the main cementitious material with water, sand, gravel, and, if necessary, chemical admixtures and mineral admixtures in appropriate proportions, through uniform mixing, compaction, and curing and hardening.

[0040] Embodiment 1

[0041] This embodiment provides a corrosion-resistant concrete composite column.

[0042] The present embodiment provides a corrosion-resistant concrete composite column, comprising an ordinary concrete column 1 and a hollow magnesium phosphate concrete column 2 coated on the outside of the ordinary concrete column. The magnesium phosphate concrete column 2 has a uniform thickness, a height of the magnesium phosphate concrete column 2 is consistent with the height of the ordinary concrete column 1, and the dimensions of the magnesium phosphate concrete column 2 other than the height are proportionally enlarged to the dimensions of the ordinary concrete column 1.

[0043] As an implementation method, both the ordinary concrete column 1 and the magnesium phosphate concrete column 2 are cubic. Figure 1 As shown, the side length of the ordinary concrete column 1 is smaller than the side length of the magnesium phosphate concrete column 2.

[0044] As an implementation mode, both the ordinary concrete column 1 and the magnesium phosphate concrete column 2 are cylinders, and the outer diameter of the ordinary concrete column 1 is equal to the inner diameter of the magnesium phosphate concrete column 2 .

[0045] As an implementation mode, the ordinary concrete column 1 is cast by reinforced concrete or plain concrete or ordinary Portland cement.

[0046] As an implementation mode, the magnesium phosphate concrete column 2 is cast by mixing magnesium phosphate cementitious material with a certain proportion of aggregate and water to obtain a fluid slurry.

[0047] The thickness of the outer magnesium phosphate concrete column 2 is less than 3 cm. If the protective layer of the reinforced concrete column includes a hollow magnesium phosphate concrete column and some other protective materials, more than 50% of the protective layer of the reinforced concrete column is magnesium phosphate concrete. The maximum aggregate particle size of the magnesium phosphate concrete column 2 is less than 1 cm, ensuring that the outer magnesium phosphate concrete column 2 has good fluidity when poured.

[0048] If the thickness of the outer magnesium phosphate concrete column 2 is less than 2 cm, the maximum aggregate particle size of the magnesium phosphate concrete column 2 is less than 5 mm.

[0049] The magnesium phosphate cement concrete column 2 has a magnesium phosphate cement concrete aggregate to magnesium phosphate cementitious material mass ratio of less than 1.5, and a magnesium phosphate cementitious material mass ratio of less than 0.3.

[0050] Alternatively, the magnesium phosphate cement concrete column 2 uses a magnesium phosphate cement concrete in which the mass ratio of aggregate to magnesium phosphate cementitious material is less than 2, and the mass ratio of water to magnesium phosphate cementitious material is less than 0.4.

[0051] The present embodiment provides a corrosion-resistant concrete composite column, which is composed of two nested inner and outer concrete columns. The inner column is an ordinary concrete column, and the outer column is a hollow magnesium phosphate concrete column with excellent corrosion resistance. It is resistant to sulfate and chloride corrosion and can be used in seawater environments, salt lake environments, saline-alkali lands, and soils with extremely high sulfate content.

[0052] The corrosion-resistant concrete composite column provided in this embodiment reduces the thickness of the magnesium phosphate concrete column, thereby reducing the production cost of the overall composite column.

[0053] The present embodiment provides a corrosion-resistant concrete composite column, in which the magnesium phosphate concrete column body is made entirely of inorganic materials. Compared with the existing concrete columns using organic protective materials, the column is more environmentally friendly and durable.

[0054] The present embodiment provides a corrosion-resistant concrete composite column, wherein the outer layer adopts a magnesium phosphate concrete column body, which is weakly alkaline and has good compatibility with marine organisms when used in a marine environment.

[0055] The corrosion-resistant concrete composite column provided in this embodiment has a magnesium phosphate cement concrete column body as an outer layer, and does not change the ordinary concrete mix ratio and reinforcement conditions of the inner ordinary concrete column body.

[0056] Embodiment 2

[0057] This embodiment provides a preparation device for a corrosion-resistant concrete composite column, wherein the corrosion-resistant concrete composite column adopts the corrosion-resistant concrete composite column described in Example 1, and the preparation device includes an inner mold 3, an outer mold, a connecting rod 4 and a limit block 5.

[0058] like Figure 2 , Figure 3 and Figure 4 As shown, the inner mold 3 is a bottomless and hollow cylinder or cube.

[0059] A plurality of evenly distributed connecting rods 4 are arranged on the top of the inner mold 3, the first end of the connecting rod 4 is fixedly connected to the top of the inner mold 3, and the second end of the connecting rod 4 is fixedly connected to the top of the limit block 5. After connection, the limit block 5 is parallel to the central axis of the inner mold 3.

[0060] The connecting rod 4 is a telescopic rod and is provided with a scale, so as to adjust the distance between the inner mold 3 and the outer mold.

[0061] The outer mold is also a bottomless and hollow cylinder or cube, and the height of the outer mold is smaller than that of the inner mold 3 .

[0062] If both the inner mold and the outer mold are cylinders, the radius of the inner mold is smaller than the radius of the outer mold, and the radius difference between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column 2, and the radius of the inner mold is the radius of the ordinary concrete column 1.

[0063] If both the inner mold and the outer mold are cubes, the side length of the inner mold is smaller than the side length of the outer mold, and half of the difference in side length between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column 2, and the side length of the inner mold is the side length of the ordinary concrete column 1.

[0064] In this embodiment, the inner mold is made of PET plastic and has an integrated molding structure.

[0065] In this embodiment, the outer mold is made of steel plate.

[0066] like Figure 5 As shown, if the outer mold is a cylinder, the outer mold is composed of two semicircular plates 6, a connecting block 7 is provided at the first end of each semicircular plate, a groove 8 is provided on the outer surface of the second end of each semicircular plate, the connecting block 7 and the groove 8 are adapted to each other, the two semicircular plates 6 are connected by the connecting block 7 and the groove 8, and bolts are fixedly provided on the outer side of the groove 8, and bolt holes adapted to the bolts are provided on the connecting block 7.

[0067] like Figure 6 As shown, if the outer mold is a cube, the outer mold is composed of four square plates 9, and a connecting block 7 is provided at the first end of each square plate 9. The two are L-shaped after being fixed, and a groove 8 is provided on the outer surface of the second end of each square plate 9. The connecting block 7 and the groove 8 are adapted to each other. The two square plates 9 are connected by the connecting block 7 and the groove 8, and a bolt 10 is fixedly provided on the outer side of the groove 8, and a bolt hole adapted to the bolt is provided on the connecting block 7.

[0068] During use, a semicircular plate 6 is fitted with the connecting block 7 and the groove 8 of another semicircular plate 6 (or, the connecting blocks 7 and the grooves 8 of four square plates 9 are fitted in sequence), and after being connected by bolts, bolt holes and nuts, an outer mold is obtained, the inner mold 3 is placed in the outer mold, and the length of the connecting rod 4 is adjusted. When the lengths of all connecting rods 4 are the same, the inner surface of the limit block 5 fits exactly with the outer surface of the outer mold, and the central axis of the inner mold 3 and the outer mold are consistent at this time; then, ordinary concrete is injected into the inner mold, and magnesium phosphate concrete is injected into the outer mold; after the magnesium phosphate cement concrete solidifies and before the internal ordinary concrete solidifies, the inner mold 3 is lifted, and then the ordinary concrete is made dense and tightly combined with the outer layer of magnesium phosphate concrete by vibration and the like; after the ordinary concrete solidifies, the outer mold is removed to obtain a corrosion-resistant concrete composite column as described in Example 1.

[0069] In this embodiment, the setting time of magnesium phosphate concrete and ordinary concrete in the composite column is measured. The cone of the cement mortar standard consistency meter is used to contact the concrete surface. Relying on the cone's own gravity, if there is no obvious mark on the surface, it indicates that the concrete is completely set and hardened.

[0070] The present embodiment provides a preparation device for a corrosion-resistant concrete composite column. Through an inner mold and an outer mold, different concretes can be poured simultaneously. The integrated design of the inner mold can enable the inner mold to be lifted after the magnesium phosphate cement concrete solidifies and before the ordinary concrete inside solidifies, so that the magnesium phosphate concrete serving as a concrete protective layer is seamlessly combined with the ordinary concrete.

[0071] The present embodiment provides a device for preparing a corrosion-resistant concrete composite column. By setting a connecting rod and a limit block, the central axes of the inner mold and the outer mold can be made consistent, and the uniformity of the thickness of the magnesium phosphate concrete column can be controlled.

[0072] The present embodiment provides a preparation device for a corrosion-resistant concrete composite column, wherein an outer mold is used for casting magnesium phosphate concrete. Magnesium phosphate concrete has the characteristics of fast coagulation and hardening and can coagulate and harden under negative temperature conditions. Therefore, the construction speed of the composite column can be increased compared with that of an ordinary concrete column. After demolding, there is no need to perform thermal insulation and moisture maintenance on the outer surface of the column, especially construction can be performed under ambient temperature below 5°C or even under negative temperature conditions.

[0073] The preparation device of a corrosion-resistant concrete composite column provided in the embodiment is particularly suitable for concrete structures with high corrosion resistance requirements. Since magnesium phosphate concrete can achieve rapid coagulation and hardening and generate a certain amount of heat in the early stage, it can increase the coagulation and hardening rate of the inner layer of ordinary concrete, reduce the ordinary concrete maintenance links, and speed up the construction speed overall.

[0074] This embodiment provides a preparation device for corrosion-resistant concrete composite columns, which can integrate concrete casting and later protection, not only simplifying the preparation process, but also allowing magnesium phosphate concrete as a concrete protective layer to be seamlessly combined with ordinary concrete.

[0075] Experiment 1: Under the condition of ambient temperature of 25℃ and relative humidity of 60%, a 20cm*20cm*20cm cubic outer mold was used, and the inner mold was placed in the outer mold, with the inner mold and the inner side of the outer mold spaced 30mm apart; dead-burned magnesium oxide with a MgO content of 90%, 10% borax, 25% diammonium phosphate and 100% sand were added to the mass of magnesium oxide, and then 25% water was added to the mass of magnesium oxide, and fluid magnesium phosphate concrete was prepared after sufficient stirring; ordinary concrete was prepared according to the C40 strength grade and slump 20cm ordinary concrete mix ratio. The prepared freshly mixed magnesium phosphate concrete and ordinary concrete were injected into the outer mold and the inner mold respectively at the same time, and then the inner mold was lifted and vibrated for compaction. The setting time of magnesium phosphate concrete and ordinary concrete was measured, and the interface bonding between the magnesium phosphate concrete column and the ordinary concrete column in the composite column was observed after demolding.

[0076] Experiment 2: Under the condition of ambient temperature of 25℃ and relative humidity of 60%, a cylindrical outer mold with a diameter of 10cm and a height of 20cm was used, and the inner mold was placed in the outer mold, with the inner side of the inner mold and the outer mold separated by 10mm; the same ratio of magnesium phosphate concrete and ordinary concrete was used in Experiment 1 to prepare two types of concrete. The two types of concrete were poured at the same time, and after lifting the inner mold, the concrete was compacted by vibration. The setting time of magnesium phosphate concrete and ordinary concrete was measured, and the interface bonding between the magnesium phosphate concrete column and the ordinary concrete column in the composite column after demolding was observed.

[0077] Experiment 3: When the ambient temperature is 8°C, the same inner and outer molds as in Experiment 1 are used, and the remaining steps are the same as in Experiment 1. The setting time of magnesium phosphate concrete and ordinary concrete is measured, and the interface bonding between the magnesium phosphate concrete column and the ordinary concrete column in the composite column after demolding is measured.

[0078] Experiment 4: When the ambient temperature is 8°C, the same inner and outer molds as in Experiment 2 are used, and the remaining steps are the same as in Experiment 2. The setting time of magnesium phosphate concrete and ordinary concrete is measured, and the interface bonding between the magnesium phosphate concrete column and the ordinary concrete column in the composite column after demolding is measured.

[0079] Experiment 5: Under the condition of ambient temperature of 25℃ and relative humidity of 60%, a cylindrical outer mold with a diameter of 10cm and a height of 10cm was used, and the inner mold was placed in the outer mold, and the inner side of the inner mold and the outer mold were separated by 5mm; dead-burned magnesium oxide with a MgO content of 90%, 10% borax by weight of magnesium oxide, 25% diammonium phosphate, and 22% water by weight of magnesium oxide were added, and fluid magnesium phosphate concrete was prepared after sufficient stirring; ordinary concrete was prepared according to the C40 strength grade and slump 20cm ordinary concrete mix ratio. The prepared freshly mixed magnesium phosphate concrete and ordinary concrete were injected into the outer mold and the inner mold respectively at the same time; a steel bar segment with a diameter of 1cm and a length of 5cm was placed in the center of the ordinary concrete, and then the inner mold was lifted and vibrated to compact. After demolding, it was cured for 28 days, and then the upper and lower end faces of the column were sealed with epoxy resin. The sealed composite column was immersed in 5% Na2SO4 + 3.5% NaCl solution, and the solution was replaced after 12h of soaking and drying for 12h for one cycle, and the solution was replaced every cycle. After 10, 20, and 30 cycles, the epoxy sealing layer was removed, and the interface bonding and appearance between the magnesium phosphate concrete column and the ordinary concrete column were observed. The composite column was then split to observe the corrosion of the embedded steel bars.

[0080] Experiment 6: Under the conditions of ambient temperature of 25°C and relative humidity of 60%, a cylindrical outer mold with a diameter of 10 cm and a height of 10 cm was used. The inner mold was placed inside the outer mold with a spacing of 10 mm between the inner and outer side surfaces. The remaining steps were the same as those in Experiment 5.

[0081] Experiment 7: Under the conditions of ambient temperature of 25°C and relative humidity of 60%, a cylindrical outer mold with a diameter of 10 cm and a height of 10 cm was used, and the inner mold was placed in the outer mold. The inner side of the inner mold and the outer mold were spaced 10 mm apart; heavy-burned magnesium oxide with a MgO content of 90% was used, 8% borax by mass of magnesium oxide, 33.3% ammonium hydrogen phosphate and 100% sand were added, and then 28% water was added to prepare magnesium phosphate concrete with good fluidity. The other steps were the same as those in Experiment 5.

[0082] Experiment 8: Under the conditions of ambient temperature of 25°C and relative humidity of 60%, a cylindrical outer mold with a diameter of 10 cm and a height of 10 cm was used, and the inner mold was placed in the outer mold. The inner side of the inner mold and the outer mold were spaced 10 mm apart; heavy-burned magnesium oxide with a MgO content of 90% was used, and 8% borax by mass of magnesium oxide, 33.3% ammonium hydrogen phosphate and 20% water were added to prepare magnesium phosphate concrete with good fluidity. The other steps were the same as those in Experiment 5.

[0083] Comparative Example 1: Under the condition of ambient temperature of 25℃ and relative humidity of 60%, a cylindrical outer mold with a diameter of 10cm and a height of 10cm was used to prepare ordinary concrete according to the ratio of C40 and slump 20cm ordinary concrete. The prepared fresh ordinary concrete was injected into the outer mold, and a steel bar segment with a diameter of 1cm and a length of 5cm was placed in the center of the ordinary concrete. After the concrete hardened, the mold was removed and placed under standard curing conditions for curing for 28 days, and then the upper and lower end faces of the column were sealed with epoxy resin. The sealed ordinary concrete column was immersed in 5% Na2SO4 + 3.5% NaCl solution. After soaking for 12h, it was taken out and dried for 12h as one cycle, and the solution was replaced once every cycle. The appearance of the main body was observed after 10, 20 and 30 cycles, and then the column was split to observe the corrosion of the steel bars buried therein.

[0084] Comparative Example 2: Under the condition of ambient temperature of 8°C and relative humidity of 50%, ordinary concrete was prepared by using a 10cm*10cm*10cm cubic outer mold according to the C40 and slump 20cm ordinary concrete ratio. The prepared fresh ordinary concrete was injected into the outer mold at the same time. The setting and hardening of the concrete was observed. After the concrete hardened, the mold was removed and placed under standard curing conditions for 28 days, then immersed in 5% Na2SO4 + 3.5% NaCl solution. After soaking for 12 hours, it was taken out and dried for 12 hours as one cycle. The solution was replaced once every cycle, and the appearance was observed after each cycle.

[0085] Table 1 is a summary of the test results of Experiments 1-8 and Comparative Examples 1-2.

[0086] Table 1. Summary of test results of experimental examples and comparative examples

[0087]

[0088] Note: The symbol “-” in the table means there is no test content

[0089] By comparing the above embodiments and comparative examples, according to the test results and observation results in Table 1, it can be concluded that:

[0090] The composite columns of magnesium phosphate concrete and ordinary concrete prepared under all conditions have intact appearance, and the interface between the magnesium phosphate concrete column and the ordinary concrete column is clear and tightly bonded, indicating that although the composite columns use two concretes with different properties, especially those with a large difference in setting time, the obtained composite columns are still complete and dense.

[0091] For the composite column of magnesium phosphate concrete and ordinary concrete, since magnesium phosphate concrete has a fast setting time and a high temperature rise, it can promote the setting of ordinary concrete, especially when the ambient temperature is relatively low, the promoting effect is more obvious. This shows that the composite column of magnesium phosphate concrete and ordinary concrete of the present invention can be constructed at a relatively low ambient temperature.

[0092] By observing the accelerated test results of Comparative Examples 1 and 2, it can be seen that the surface of the ordinary concrete column was damaged after 30 accelerated destruction tests, while the appearance of the magnesium phosphate concrete and ordinary concrete composite column was still intact after 50 accelerated tests. The steel bars embedded in the ordinary concrete were corroded after 10 accelerated tests, while in Experiment 5, the concrete composite column with a magnesium phosphate concrete protective layer of 5 mm showed slight corrosion of the steel bars embedded in the ordinary concrete only after 50 accelerated tests.

[0093] The thicker the magnesium phosphate concrete in the composite column, the more conducive it is to promoting the coagulation of ordinary concrete, and this promotion effect is particularly obvious under low temperature conditions. The addition of aggregates in magnesium phosphate concrete will affect the protective effect of steel bars in ordinary concrete. Therefore, for ordinary reinforced concrete, magnesium phosphate concrete without aggregates should be used as much as possible, or the thickness of magnesium phosphate concrete should be increased.

[0094] By comparing Experiment 5, Experiment 6, Experiment 7 and Experiment 8, it can be seen that the phosphorus-magnesium ratio, borax dosage and water-cement ratio of magnesium phosphate concrete have no obvious effect on the protective effect of magnesium phosphate concrete, that is, concrete prepared with magnesium phosphate cementitious materials can usually meet the requirements of composite columns.

[0095] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A corrosion-resistant concrete composite column, characterized in that: It comprises an ordinary concrete column and a hollow magnesium phosphate concrete column wrapped around the outer side of the ordinary concrete column. The height of the magnesium phosphate concrete column is consistent with that of the ordinary concrete column, and the dimensions of the magnesium phosphate concrete column except the height are proportionally enlarged to those of the ordinary concrete column.

2. The corrosion-resistant concrete composite column according to claim 1, characterized in that: The magnesium phosphate concrete column has a uniform thickness.

3. The corrosion-resistant concrete composite column according to claim 1, characterized in that: The common concrete column and the magnesium phosphate concrete column are both cubes, and the side length of the common concrete column is smaller than that of the magnesium phosphate concrete column.

4. The corrosion-resistant concrete composite column according to claim 1, characterized in that: The common concrete column and the magnesium phosphate concrete column are both cylinders, and the outer diameter of the common concrete column is equal to the inner diameter of the magnesium phosphate concrete column.

5. The corrosion-resistant concrete composite column according to claim 1, characterized in that: A plurality of steel bars are arranged in the ordinary concrete column.

6. A preparation device for a corrosion-resistant concrete composite column, wherein the corrosion-resistant concrete composite column is a corrosion-resistant concrete composite column according to any one of claims 1 to 5, characterized in that: The preparation device comprises an inner mold for pouring ordinary concrete and an outer mold for pouring magnesium phosphate concrete; The inner mold is arranged inside the outer mold, and the central axes of the inner mold and the outer mold are located on a straight line.

7. The device for preparing a corrosion-resistant concrete composite column according to claim 6, characterized in that: A plurality of evenly distributed connecting rods are arranged on the top of the inner mold, a first end of each connecting rod is fixedly connected to the top of the inner mold, and a limiting block is fixedly arranged on the second end of each connecting rod; The connecting rod is a telescopic rod and is provided with a scale.

8. The device for preparing a corrosion-resistant concrete composite column according to claim 6, characterized in that: The height of the outer mold is smaller than the height of the inner mold.

9. The device for preparing a corrosion-resistant concrete composite column according to claim 6, characterized in that: The inner mold is an integrated structure.

10. The device for preparing a corrosion-resistant concrete composite column according to claim 6, characterized in that: The inner mold and the outer mold are both bottomless and hollow cylinders, and the radius of the inner mold is smaller than the radius of the outer mold. The radius difference between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column, and the radius of the inner mold is the radius of the ordinary concrete column. Alternatively, the inner mold and the outer mold are both bottomless and hollow cubes, and the side length of the inner mold is smaller than the side length of the outer mold. Half of the difference in side length between the inner mold and the outer mold is the thickness of the magnesium phosphate concrete column, and the side length of the inner mold is the side length of an ordinary concrete column.

Images