Pouring construction system and method for near-zero magnetic concrete structure

Abstract

The invention discloses a pouring construction system and method for a near-zero magnetism concrete structure, the pouring construction system comprises a vibrating device and a trowelling device, the vibrating device is used for vibrating low-magnetism concrete, and the trowelling device is used for demagnetizing and trowelling the concrete. The method comprises the following steps: firstly, vibrating cementitious material particles in the concrete to a disordered state by utilizing vibration, reducing a residual magnetism value by destroying a magnetic state of the cementitious material particles to form low-magnetism concrete, and then carrying out dynamic demagnetization on an environmental magnetic field to form low-magnetism concrete; the problem that the residual magnetism value is increased due to the fact that the low-magnetism concrete formed through vibration is magnetized by an environment magnetic field before forming a cementing material particle net-shaped lap joint structure is solved, then the residual magnetism value is prevented from being increased in the concrete hardening process, finally, surface trowelling is conducted through the trowelling device, and pouring construction of the near-zero-magnetism concrete is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of near-zero magnetic concrete construction, in particular to a pouring construction system and method for a near-zero magnetic concrete structure. BACKGROUND

[0002] Low magnetic concrete, as a kind of special concrete material, is often used in the construction of low magnetic medical rooms, low magnetic geomagnetic stations, and demagnetization laboratories, etc., to form a closed low magnetic concrete structure space and ensure that sensitive instruments and equipment are not affected by external strong magnetic fields during use.

[0003] Existing research shows that the residual magnetic value of ordinary concrete is about several hundred to several nT, and after pouring construction by various low-magnetization production means, the residual magnetic value of conventional concrete is at least 3nT, and it is easy to be magnetized by the surrounding geomagnetic field or strong magnetic field source during pouring. However, for key scientific devices such as extremely weak magnetic large scientific facilities and high-end zero magnetic medical equipment, the design requirement value of the extremely weak environmental magnetic field is extremely low, and the residual magnetic value of the concrete should not exceed 0.5nT, which is near-zero magnetic concrete. However, when using near-zero magnetic concrete for construction, although the residual magnetic value of the near-zero magnetic concrete itself meets the requirements, it is still easy to be magnetized by the environmental magnetic field during construction, which leads to an environmental magnetic field after construction that does not meet the requirements, making it extremely difficult to construct an extremely weak environmental magnetic field. The present application provides a pouring construction system and method for a near-zero magnetic concrete structure to solve the above problems. SUMMARY

[0004] The present application provides a pouring construction system and method for a near-zero magnetic concrete structure, which realizes the pouring construction of a near-zero magnetic concrete structure through demagnetization and dynamic demagnetization.

[0005] The technical solution adopted by the present application to solve the above technical problems is as follows: A pouring construction system for a near-zero magnetic concrete structure, comprising a vibrating device and a troweling device, the vibrating device is used for vibrating the concrete, and the troweling device is used for environmental demagnetization and concrete troweling. The vibrating device comprises a vibrator and a measurer, the vibrator is used for vibrating the concrete, and the measurer is used for measuring the state of the concrete after vibration. The troweling device comprises a demagnetization mechanism and a troweling mechanism, the demagnetization mechanism is arranged on the troweling mechanism, the demagnetization mechanism is used for dynamic demagnetization of the environmental magnetic field after the concrete is vibrated, and the troweling mechanism is used for troweling of the concrete after vibration.

[0006] Further, the vibrator comprises a first power device, a shielding chamber, a connecting pipe and a vibrating rod, the first power device is arranged in the shielding chamber, and the vibrating rod is connected with the first power device through the connecting pipe.

[0007] Further, the shielding chamber comprises a protection layer, a shielding layer, a protection layer and a demagnetization layer, the protection layer and the shielding layer are alternately stacked on the inner side of the protection layer, and the demagnetization layer is arranged on the outer side of the protection layer.

[0008] Further, the measuring device comprises a measuring probe and a display, the measuring probe is used to measure the phase angle of the concrete, and the display is used to display the measured phase angle of the concrete.

[0009] Further, the troweling mechanism comprises a second power device, a troweling plate and an outer frame, the second power device is arranged on the outer frame, and the troweling plate is arranged at the bottom of the outer frame and connected with the second power device. The outer frame comprises a frame, a walking wheel and a handrail, and the walking wheel and the handrail are arranged on the front side of the frame.

[0010] Further, the detection device is a magnetic flux gate, and the demagnetization device is a demagnetization coil and is arranged around the frame.

[0011] Further, the detection device is a magnetic flux gate, and the demagnetization device is a demagnetization coil and is arranged around the frame.

[0012] Further, the vibrating rod is made of 316L material, and the shielding layer is made of permalloy.

[0013] A construction method of a pouring construction system for a near-zero magnetic concrete structure, comprising the following steps, S1, concrete pouring: pouring of concrete is carried out, and layer pouring is adopted during pouring, and the layer thickness is not more than 300mm; S2, conventional vibrating of concrete: after the completion of concrete pouring, the concrete is subjected to initial conventional vibrating; S3, demagnetization vibrating of concrete: 1h before initial setting of concrete, the concrete is subjected to demagnetization vibrating, and the demagnetization vibrating is repeatedly operated in the mode of vibrating first and then measuring until the phase angle of the concrete after vibrating is not less than 85°, and then the vibrating rod is lifted out of the concrete; S4, dynamic demagnetization of concrete: the troweling equipment is transferred to the concrete after vibrating, and the environmental magnetic field is subjected to dynamic demagnetization by the demagnetization device, and the magnetic field strength generated by the demagnetization device is ten times the detected environmental magnetic field strength during dynamic demagnetization; S5, troweling of concrete: after the completion of dynamic demagnetization of concrete, the surface of the concrete is troweled by the troweling mechanism, and then the concrete is hardened after troweling.

[0014] Further, in step S4, after the dynamic demagnetization ends, the phase angle of the concrete is measured by the measuring probe, if the phase angle of the concrete is not higher than 10 degrees, the dynamic demagnetization is stopped, if the phase angle of the concrete is higher than 10 degrees, the dynamic demagnetization is performed again; when the phase angle of the concrete is 10-20 degrees, the dynamic demagnetization is performed again for 1 minute, and the demagnetization time is increased by 1 minute for each 10 degrees of the phase angle of the concrete.

[0015] The application has the following advantages: First, the cementitious material particles in the concrete are vibrated to a disordered state by vibration, the remanence value is reduced by destroying the magnetic state, and low-magnetic concrete is formed, then the environmental magnetic field is dynamically demagnetized, the problem that the low-magnetic concrete formed by vibration is magnetized by the environmental magnetic field and the remanence value increases before the formation of the cementitious material particle net-like lap joint structure is avoided, and the remanence value increase in the hardening process of the concrete is avoided, finally the surface is smoothed by the smoothing device, and the pouring construction of near-zero magnetic concrete is realized. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A vibration demagnetization working state diagram of the vibration device of the application is shown in the figure; Figure 2 A dynamic demagnetization working state diagram of the smoothing device of the application in the environment is shown in the figure; Figure 3 A structure diagram of the smoothing device of the application is shown in the figure; Figure 4 A structure diagram of the vibrator of the application is shown in the figure; Figure 5 A layered structure diagram of the shielding room of the application is shown in the figure; Figure 6 A phase angle and remanence value relationship diagram in the concrete vibration demagnetization process of the application is shown in the figure; Figure 7 A concrete remanence value and dynamic demagnetization stage relationship diagram of the application is shown in the figure.

[0017] The figure shows: 100, vibration device; 200, smoothing device; 1, vibrator; 11, first power device; 12, shielding room; 121, protective layer; 122, shielding layer; 123, protective layer; 124, demagnetization layer; 13, connecting pipe; 14, vibrating rod; 2, measuring device; 21, measuring probe; 22, display; 3, demagnetization mechanism; 31, detection device; 32, demagnetization device; 4, smoothing mechanism; 41, second power device; 42, smoothing plate; 43, outer frame; 431, frame; 432, walking wheel; 433, handrail. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0019] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0020] As shown in Figure 1 , 2 A pouring construction system for near-zero magnetic concrete structure, comprising a vibrating device 100 for vibrating the concrete and a troweling device 200 for environmental demagnetization and concrete troweling.

[0021] The specific principle of the present application is as follows: low magnetic concrete is easily magnetized by the environmental magnetic field during pouring due to its low residual magnetism value and the fact that it is in a state of being easily magnetized before solidification, resulting in an increase in the residual magnetism value, and the residual magnetism value after hardening does not meet the requirements of the extremely weak environmental magnetic field. Therefore, during concrete pouring, the concrete is first vibrated using a vibrator 1, and the phase angle of the concrete is measured during the vibration process. The phase angle is a direct observation parameter representing the degree of lapping of the network lapping structure of the cementitious material particles in the concrete. When the network structure between the particles is destroyed, the cementitious material particles can move and rotate freely, and the magnetic structure formed after being magnetized by the environmental magnetic field disappears immediately. By reading the phase angle, the residual magnetism value of the concrete at this time is obtained. When the residual magnetism value meets the requirements, i.e., after the formation of low magnetic concrete, the vibration is stopped, and then the environmental magnetic field is dynamically demagnetized by a demagnetization mechanism 3 to avoid the low magnetic concrete that has not formed a network lapping structure after vibration from being magnetized by the environmental magnetic field again. After dynamically demagnetizing the environmental magnetic field, the low magnetic concrete is troweled to complete the construction, and the residual magnetism value of the final concrete structure is less than 0.5nT, realizing the pouring construction of near-zero magnetic concrete.

[0022] Further, through laboratory experiment observation, the concrete with higher residual magnetization value, the flocculation network structure of cementitious material particles will be destroyed during vibrating, the particles can move freely and re-order, while through detection, it is found that the phase angle of the concrete will also change synchronously, and the greater the value of the phase angle, the higher the degree of destruction of the flocculation network structure, i.e. the existing magnetic structure, when the phase angle reaches 85° or above, the flocculation network structure of the cementitious material particles in the concrete reaches the degree of complete destruction, the cementitious material particles move and rotate freely, at this time, the concrete is in a non-magnetic or low-magnetic state, and after stopping vibrating, the cementitious material particles will be affected by the magnetization of the external magnetic field and move towards the direction of the strong magnetic field, thereby forming a magnetic domain structure and showing magnetism, if the external magnetic field is dynamically demagnetized by an alternating magnetic field immediately after vibrating, since the direction of the external magnetic field is indefinite, the cementitious material particles will also be in a disordered arrangement state, and the cementitious material particles hardened in a disordered state will not show uniform magnetic ordering, thereby showing low-magnetic or near-zero-magnetic concrete. With the solidification of the concrete, the degree of freedom of the cementitious material particles also decreases, and with the decrease of the degree of freedom of the cementitious material particles, a stable flocculation network structure will be formed between the cementitious material particles, when the phase angle is not higher than 10°, it indicates that a stable flocculation network structure has been completely formed between the cementitious material particles, at this time, the external magnetic field environment cannot magnetize the cementitious material particles, and thus cannot cause the residual magnetization value of the concrete to increase, thereby ensuring that the residual magnetization value of the hardened concrete is not higher than 0.5nT, and realizing the construction of near-zero-magnetic concrete building structure.

[0023] As shown in Figure 6 , using commercially available ordinary cement and aggregate with a residual magnetization value not higher than 1nT, the concrete is prepared in a conventional environmental magnetic field, after the preparation of the concrete is completed, the concrete is vibrated to realize demagnetization, the residual magnetization value of the same kind of concrete prepared when vibrated to different phase angles, since the residual magnetization value of the commercially available concrete itself is between dozens to hundreds, and the higher the degree of destruction of the existing magnetic structure of the concrete by vibrating, the lower the residual magnetization value, when vibrated to a phase angle of only 10°, the residual magnetization value is as high as 115.7nT, and when the phase angle reaches 85°, the residual magnetization value is only 0.4nT, meeting the requirement of near-zero-magnetic.

[0024] As shown in Figure 7As shown, after the concrete is vibrated and forms the near-zero magnetic concrete, in order to avoid the concrete being magnetized by the environmental magnetic field again, the dynamic demagnetization needs to continue until the concrete forms a stable mesh structure, and then the concrete will remain in the near-zero magnetic state. Experiments show that if the dynamic demagnetization is stopped at different stages before the concrete forms a stable mesh structure, the residual magnetism of the concrete will have a large difference. After the concrete is vibrated and demagnetized, if the dynamic demagnetization is not performed, the concrete will be magnetized again during the hardening process, and the residual magnetism of the hardened concrete is 113.8 nT. If the dynamic demagnetization is performed after the concrete is vibrated and demagnetized until the concrete forms a stable mesh structure, that is, the dynamic demagnetization is stopped when the phase angle of the concrete is not higher than 10°, the residual magnetism of the hardened concrete is 0.3 nT, and the residual magnetism of the concrete will not increase again.

[0025] As shown in Figure 1 , 4 , the vibrating device 100 includes a vibrator 1 and a measurer 2. The vibrator 1 is used for concrete vibration, and the concrete is demagnetized by vibration to form low-magnetic concrete by destroying the magnetic structure in the concrete. The measurer 2 is used to measure the state of the concrete after vibration, and the residual magnetism of the concrete at this time is measured by measuring the phase angle of the concrete. When the phase angle meets the requirements, the vibration is stopped.

[0026] As shown in Figure 2 , 3 , the troweling device 200 includes a demagnetizing mechanism 3 and a troweling mechanism 4. The demagnetizing mechanism 2 is arranged on the troweling mechanism 4. The demagnetizing mechanism 2 is used to dynamically demagnetize the environmental magnetic field after the concrete is vibrated. The troweling mechanism 4 is used to trowel the near-zero magnetic concrete after vibration.

[0027] Further, the vibrator 1 includes a first power device 11, a shielding chamber 12, a connecting pipe 13, and a vibrating rod 14. The first power device 11 is arranged in the shielding chamber 12 and is used to provide power for the vibrating rod 14. The shielding chamber 12 is used to shield the electromagnetic field generated when the first power device 11 works. The vibrating rod 14 is connected with the first power device 11 through the connecting pipe 13. The connecting pipe 13 is used to transmit the power of the first power device 11 to the vibrating rod 14.

[0028] As shown in Figure 5As shown, the shielding chamber 12 further includes a protective layer 121, a shielding layer 122, a protective layer 123, and a demagnetizing layer 124. The protective layers 121 and 122 are alternately stacked on the inner side of the protective layer 123. One layer of protective layer 121 and one layer of shielding layer 122 are alternately stacked, and three layers of shielding layers 122 are provided. A layer of protective layer 121 is provided between the outermost shielding layer 122 and the protective layer 123, for a total of four layers of protective layers 121. The demagnetizing layer 124 is provided on the outer side of the protective layer 123. The shielding chamber 12 using multiple shielding layers 122 has an overall remanence value of no more than 30nT.

[0029] Furthermore, the vibrating rod 14, the protective layer 123, and the metal components in the device are all made of 316L stainless steel, which is a near-zero magnetic material and will not magnetize the concrete. The protective layer 121 is a flexible insulating material that plays a buffering and protective role. The shielding layer 122 is Permalloy, which is a commonly used magnetic shielding material. The demagnetization layer 124 is a demagnetization coil. The shielding layer 122 is easily magnetized by the magnetic field, so it needs to be demagnetized by the demagnetization layer 124 before use.

[0030] like Figure 1 As shown, further, the measuring device 2 includes a measuring probe 21 and a display 22, wherein the measuring probe 21 is used to extend into the concrete to measure the phase angle of the concrete, and the display 22 is used to display the measured phase angle of the concrete.

[0031] Furthermore, the measuring probe 21 includes a motor, a probe, a normal force sensor and a linear optical encoder. The probe is installed on the motor, and the motor adopts an EC motor. The EC motor is connected to the probe through an air bearing to ensure high-precision transmission with ultra-low deviation. The EC motor drives the probe to rotate in the concrete. The EC motor applies stress through the probe. The normal force sensor is connected to the probe to measure the stress applied to the probe. The linear optical encoder is connected to the EC motor. When the EC motor rotates, the grating produces synchronous displacement. The receiver reads the angular displacement data of the grating, measures the angular displacement of the EC motor, and calculates the shear strain value based on the angular displacement.

[0032] The phase angle is calculated by calculating the shear stress value from the collected torque value, and calculating the shear strain value from the collected angular displacement, and then obtaining the phase angle of the concrete. The specific process is as follows: the probe is set with an angular frequency ω and a strain amplitude γ0, the strain amplitude is realized by controlling the angular displacement, the EC motor drives the probe to rotate according to the sine wave position instruction, and the actual applied strain signal γ(t) = γ0*sin(ωt); the concrete generates resistance to the applied strain, which is manifested as torque M(t), the normal force sensor measures M(t) in real time, and the measured torque is converted into stress τ(t) through geometric conversion, τ(t) = τ0*sin(ωt+δ); the collected strain signal and stress signal are subjected to Fourier transform and comparison by using the Fourier transform method, the time difference between them is determined, and then the time difference is converted into the phase angle difference δ, so that the phase angle of the concrete is obtained. After measuring the phase angle of the concrete, the corresponding residual magnetization value of the concrete at this time is found out through a comparison table.

[0033] As shown in Figure 3 , further, the troweling mechanism 4 comprises a second power device 41, a troweling plate 42 and an outer frame 43, the second power device 41 is arranged on the outer frame 43 and used to drive the troweling plate 42, the troweling plate 42 is arranged at the bottom of the outer frame 43 and connected with the second power device 41, and used to trowel the concrete surface. The outer frame 43 comprises a frame 431, walking wheels 432 and handrails 433, the frame 431 is used to mount the troweling plate 42, the walking wheels 432 and the handrails 433, and the walking wheels 432 and the handrails 433 are arranged at the front side of the frame 431.

[0034] As shown in Figure 2 , 3 , further, the demagnetization mechanism 3 comprises a detection device 31 and a demagnetization device 32, the detection device 31 is arranged on the frame 431 and used to detect the environmental magnetic field, and the demagnetization device 32 is a demagnetization coil and arranged around the outer periphery of the frame 431 and used to demagnetize the environmental magnetic field.

[0035] As shown in Figure 2 , 3 , further, the frame 431 comprises a frame body and an outer cover, the frame body is arranged on the upper part of the outer cover and used to mount the second power device 41, the walking wheels 432 and the handrails 433, the outer cover is a cover body with an open bottom, the troweling plate 42 is arranged in the outer cover, the troweling plate 42 and the outer cover are made of 316L stainless steel material, and the demagnetization device 32 is arranged around the outer periphery of the outer cover.

[0036] A construction method of a pouring construction system for a near-zero magnetic concrete structure, comprising the following steps, S1, concrete pouring: pouring of concrete is carried out, and layer pouring is adopted during pouring, and the layer thickness is not more than 300 mm; S2, concrete conventional vibration: after the completion of concrete pouring, the concrete is initially conventionally vibrated to make the concrete dense; S3, concrete demagnetization vibration: 1h before the initial setting of the concrete, the concrete is demagnetization vibrated. The demagnetization vibration is repeated by first vibrating and then measuring until the phase angle of the concrete after vibration is not less than 85°, and then the vibrating rod 14 is lifted out of the concrete; S4, concrete dynamic demagnetization: the troweling device 200 is transferred to the concrete after the vibration is completed, and the environmental magnetic field is dynamically demagnetized by the demagnetization device 32. During dynamic demagnetization, the magnetic field strength generated by the demagnetization device 32 is ten times the detected environmental magnetic field strength. The dynamic demagnetization is achieved by the strong alternating magnetic field generated by the demagnetization device 32 to offset the environmental magnetic field acting on the vibrated concrete, and the demagnetization is achieved by the hysteresis loop decrement, thereby avoiding the environmental magnetic field from magnetizing the low-magnetic concrete vibrated by demagnetization, and ensuring that the concrete is in a state of low remanence value to form a net-like lap joint structure and harden; After the dynamic demagnetization is completed, the phase angle of the concrete is measured by the measuring probe 21. If the phase angle of the concrete is not higher than 10°, the dynamic demagnetization is stopped. If the phase angle of the concrete is higher than 10°, the dynamic demagnetization is performed again. When the phase angle of the concrete is 10-20°, the dynamic demagnetization is performed again for 1 minute. If the phase angle of the concrete exceeds 10°, the dynamic demagnetization time is increased by 1 minute. S5, concrete troweling: after the dynamic demagnetization of the concrete is completed, the concrete surface is troweled by the troweling mechanism 4, and the concrete is allowed to solidify after troweling.

[0037] Further, during the concrete demagnetization vibration in step S3, the concrete is vibrated by the vibrating rod 14 at a speed of 0.3-0.5m / s, and after the vibrating rod 14 is inserted into the concrete, the concrete is vibrated at a frequency of 150Hz for 8s, then the measuring probe 21 is inserted into the concrete at a distance of 10-15cm from the rod head, and the concrete is oscillated at a shear strain of not higher than 1% and a frequency of 1Hz for 2s-5s to measure the phase angle of the concrete. During the measurement, if the phase angle of the concrete is less than 85°, the frequency of the vibrating rod 14 is increased by 50Hz, and the concrete is vibrated for 8s. The phase angle of the concrete is measured again. If the phase angle of the concrete is not less than 85°, the vibration is stopped. If the phase angle of the concrete is still less than 85°, the frequency of the vibrating rod 14 is increased by 50Hz, and the concrete is vibrated for 8s. The above operation is repeated until the phase angle of the concrete is not less than 85°. After the phase angle of the concrete meets the requirements, the vibrating rod 14 is lifted out at a speed of 0.1m / s.

[0038] Further, the concrete is demagnetized and vibrated in step S3, the vibration interval is controlled within 1.0 times of the effective action radius of the vibrating rod, and the quincunx distribution is adopted.

[0039] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the application can be implemented in other particular forms without departing from the spirit or essential characteristics of the application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein and no single feature should be considered limiting of the claims in the absence of an explicitly stated limitation to that effect.

Claims

1. A pouring construction system for near-zero magnetic concrete structure, characterized by: It comprises a vibrating device (100) and a smoothing device (200), wherein the vibrating device (100) is used for vibrating concrete, and the smoothing device (200) is used for environmental demagnetization and concrete smoothing; The vibrating device (100) comprises a vibrator (1) and a measuring device (2), wherein the vibrator (1) is used for vibrating concrete, and the measuring device (2) is used for measuring the state of the concrete after vibration; The smoothing device (200) comprises a demagnetization mechanism (3) and a smoothing mechanism (4), wherein the demagnetization mechanism (2) is arranged on the smoothing mechanism (4), the demagnetization mechanism (2) is used to dynamically demagnetize the environmental magnetic field after the concrete is vibrated, and the smoothing mechanism (4) is used to smooth the concrete after the concrete is vibrated.

2. A pouring construction system for near-zero magnetic concrete structure according to claim 1, characterized in that: The vibrator (1) comprises a first power device (11), a shielding chamber (12), a connecting pipe (13) and a vibrating rod (14); the first power device (11) is arranged in the shielding chamber (12); and the vibrating rod (14) is connected to the first power device (11) via the connecting pipe (13).

3. A pouring construction system for near-zero magnetic concrete structure according to claim 2, characterized in that: The shielding room (12) comprises a protective layer (121), a shielding layer (122), a protective layer (123) and a demagnetizing layer (124); the protective layer (121) and the shielding layer (122) are alternately stacked and arranged on the inner side of the protective layer (123); and the demagnetizing layer (124) is arranged on the outer side of the protective layer (123).

4. A pouring construction system for near-zero magnetic concrete structure according to claim 1, characterized in that: The measuring device (2) comprises a measuring probe (21) and a display (22), wherein the measuring probe (21) is used to extend into concrete to measure the phase angle of the concrete, and the display (22) is used to display the measured phase angle of the concrete.

5. The pouring construction system for near-zero magnetic concrete structure according to claim 1, characterized in that: The trowel mechanism (4) comprises a second power device (41), a trowel plate (42) and an outer frame (43), wherein the second power device (41) is arranged on the outer frame (43), and the trowel plate (42) is arranged at the bottom of the outer frame (43) and connected to the second power device (41); The outer frame (43) comprises a frame (431), running wheels (432) and armrests (433), wherein the running wheels (432) and armrests (433) are arranged on the front side of the frame (431).

6. A pouring construction system for near-zero magnetic concrete structure according to claim 5, characterized in that: The demagnetization mechanism (3) comprises a detection device (31) and a demagnetization device (32); the detection device (31) is arranged on the frame (431) and is used to detect the ambient magnetic field; the demagnetization device (32) is arranged on the periphery of the frame (431) and is used to demagnetize the ambient magnetic field.

7. A pouring construction system for near-zero magnetic concrete structure according to claim 6, characterized in that: The detection device (31) is a fluxgate, and the demagnetization device (32) is a demagnetization coil, which is wound around the outer periphery of the frame (431).

8. The pouring construction system for near-zero magnetic concrete structure according to claim 3, characterized in that: The vibrating rod (14) is made of 316L material, and the shielding layer (122) is Permalloy.

9. The construction method of a pouring construction system for a near-zero magnetic concrete structure according to claim 1, characterized in that: The following steps are included: S1, concrete pouring: pouring concrete in layers with a layer thickness not exceeding 300mm; S2, conventional concrete vibration: After the concrete is poured, the concrete is vibrated for the first time; S3, concrete demagnetization and vibration: 1 hour before the initial setting of the concrete, the concrete is demagnetized and vibrated. During the demagnetization and vibration, the method of vibrating first and then measuring is repeated until the phase angle of the concrete after vibration is not less than 85°. Then the vibrating rod (14) is lifted out of the concrete. S4, dynamic demagnetization of concrete: transferring the leveling device (200) to the concrete after vibration, and dynamically demagnetizing the ambient magnetic field using the demagnetization device (32). During dynamic demagnetization, the magnetic field intensity generated by the demagnetization device (32) is ten times the detected ambient magnetic field intensity; S5, concrete smoothing: After the dynamic demagnetization of the concrete is completed, the concrete surface is smoothed by the smoothing mechanism (4), and then the concrete is allowed to harden.

10. The construction method of a pouring construction system for a near-zero magnetic concrete structure according to claim 9, characterized in that: In step S4, after the dynamic demagnetization is completed, the phase angle of the concrete is measured by the measuring probe (21). If the phase angle of the concrete is not higher than 10°, the dynamic demagnetization is stopped. If the phase angle of the concrete is higher than 10°, the dynamic demagnetization is performed again. When the concrete phase angle is between 10 and 20 degrees, dynamic demagnetization is performed again for 1 minute, and the dynamic demagnetization time is increased by 1 minute for every 10 degrees the concrete phase angle exceeds.

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