A magnetic self-healing concrete responsive loading device

Abstract

The present invention discloses a magnetic self-healing concrete response loading device, including a shell, a shell cover, a power supply system, a control system, and a telescopic module, a rotation module, and a magnetic field control module all connected to the power supply system and the control system; the telescopic module, the rotation module, and the magnetic field control module are connected in sequence, the telescopic module controls the telescopic movement of the magnetic field control module, and the rotation module controls the rotational movement of the magnetic field control module. Under the action of the response loading device, the magnetic self-healing concrete can achieve magnetic response, and can be interfered with by manual or mechanical alarms to change the static rupture of traditional self-repairing microcapsules into controllable rupture, greatly improve the capsule rupture efficiency, and significantly improve the repair efficiency of self-repairing concrete, exploring a new way for the preparation and application of intelligent concrete.

Description

Technical Field

[0001] The invention relates to the field of functional building materials, in particular to a magnetic self-healing concrete response loading device. Background Art

[0002] Concrete materials are the core materials of modern construction due to their low cost and superior performance. With the continuous progress of society, different types of self-healing concrete have appeared both at home and abroad, which can monitor, warn and self-repair internal damage of the structure in real time.

[0003] Magnetic powder is a new type of nanomaterial that can respond to external magnetic fields. It has excellent characteristics such as wide range of raw materials and good electromagnetic properties. It is often added to make objects magnetic. Consider adding it to microcapsules and assisting with external response devices, which may improve the efficiency of microcapsule rupture to a certain extent.

[0004] In order to find a new magnetic field-responsive concrete that can greatly improve the repair effect, the preparation materials and repair principles of concrete are determined. The present invention designs a magnetic micro-nano powder field-responsive concrete preparation and response loading device, prepares a field-responsive concrete doped with magnetic powder capsules, and uses the characteristics of magnetic powder responding to the external magnetic field through the response loading device to improve the repair effect of the self-healing concrete doped with magnetic powder capsules. Materials such as nano carbon black and steel fiber will also give concrete strong conductivity, exploring a new way for the preparation of intelligent field-responsive concrete, and providing the possibility of realizing external intelligent adjustment and repair effects. A simple, low-cost and easy-to-carry response loading device is used to promote the diffusion of adhesives, which can greatly improve the repair efficiency of capsules for internal damage to concrete. Summary of the invention

[0005] In order to solve the problems existing in the existing self-healing concrete, the present invention provides a magnetic self-healing concrete response loading device. In the present invention, a suitable preparation ratio of magnetic field responsive concrete is selected based on traditional concrete, and the response loading device is used to realize the transformation of field responsive concrete microcapsules from static rupture to controllable rupture, thereby greatly improving the rupture efficiency of microcapsules in concrete and significantly enhancing the self-healing effect.

[0006] A magnetic self-healing concrete response loading device comprises a shell, a shell cover, a power supply system, a control system, and a telescopic module, a rotation module and a magnetic field control module all connected to the power supply system and the control system; the telescopic module, the rotation module and the magnetic field control module are connected in sequence, the telescopic module controls the telescopic movement of the magnetic field control module, and the rotation module controls the rotational movement of the magnetic field control module.

[0007] The telescopic module includes a slide rail, a pulley, a force plate, a first push rod, a movable shaft, a second push rod, a column, a turntable, a pulley, a belt and a first motor. The pulley is combined with the force plate by welding, and the slide rail is installed on the front and rear walls of the device. A pulley is connected to the center of the bottom of the turntable. The force plate is fixedly connected to the first push rod, and the output shaft of the motor is connected to the pulley by a belt. A column is provided on the edge of the upper surface of the turntable, and one end of the second push rod is rotatably connected to the column, and the other end is rotatably connected to the first push rod through a movable shaft.

[0008] The rotating module includes a second motor, a rotating shaft and a rotating block, and the rotating block is connected to the force application plate of the telescopic module.

[0009] The magnetic field control module includes a circular disk, which is provided with a plurality of outer slide rails extending outward from the center of the circle, and each outer slide rail is provided with a small slidable circular disk. Each small circular disk is provided with a plurality of inner slide rails extending outward from the center of the circle, and each inner slide rail is provided with a small slidable magnet.

[0010] There are five inner slide rails and five outer slide rails. Each small circular plate and small magnetic steel is connected with a telescopic device. The telescopic device can have the same structure and principle as the telescopic module.

[0011] Beneficial effects: The magnetic micro-nano powder field response loading device is flexible and portable. In practical applications, the response loading device can be installed to cooperate with magnetic micro-nano powder field response concrete for use, or according to the traditional non-load-bearing landscape building concrete maintenance period of 10-14 months, after 10-14 months, the response loading device can be carried manually, and the portable field response loading is used to control the external magnetic field, which responds to the internal magnetic micro-nano powder microcapsules, causing the unbroken microcapsules to rupture and increase the degree of rupture. At the same time, the direction of the external magnetic field changes continuously, allowing the magnetic powder with a sticky core material to flow evenly in the concrete gaps, thereby increasing the efficiency of repairing broken concrete.

[0012] The magnetic micro-nano powder field responsive concrete and responsive loading device prepared by the present invention can be used in the field of dynamic response and intelligent and efficient self-repair of damage conditions of infrastructure such as dams, bridges, sluices, coasts and offshore projects.

[0013] Magnetic self-healing concrete can achieve magnetic response under the action of the response loading device, and can interfere with the magnetic field through manual or mechanical alarms, turning the static rupture of traditional self-repairing microcapsules into controllable rupture, greatly improving the capsule rupture efficiency and significantly improving the repair efficiency of self-repairing concrete, exploring a new path for the preparation and application of smart concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a schematic diagram of the overall structure of the response loading device.

[0015] Figure 2 It is a schematic diagram of the telescopic module. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0017] It should be noted that, in the description of the present invention, the directions or positional relationships indicated by terms such as "front", "rear", "left", "right", "up", "down", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0018] Example 1 Preparation of magnetic self-healing capsules

[0019] 1) Synthesis of urea formaldehyde prepolymer: Add 1.5g formaldehyde and 2g urea to a 500mL three-necked flask, wait for the urea to dissolve, then drop triethanolamine into it, adjust the pH to 8, heat and keep the temperature at 70°C, slowly stir and keep the temperature for 1h to obtain a viscous liquid, then add distilled water twice the mass of the prepolymer, wait for about 30min, and a stable and transparent urea formaldehyde prepolymer can be formed, which is then placed aside for later use;

[0020] 2) Preparation of core material emulsion: Weigh 0.4 g epoxy resin (E-52), 2.5 g emulsifier polyoxyethylene sorbitan monooleate (Tween-80), 0.25 small molecule epoxy resin (E-52) and 8 g distilled water, place in a 500 mL three-necked flask, stir with a stirrer at a speed of 500 r / min, spray 1.5 g magnetic powder liquid into it with a differential device, mix and stir for about 1 hour to obtain a core material emulsion.

[0021] 3) Microencapsulation: urea formaldehyde prepolymer (10 g) is added dropwise (30-40 drops / min) to a core material emulsion (10 g) containing magnetic powder at a rotation speed of 500 r / min, and the pH is adjusted to 3 with hydrochloric acid, and the temperature is maintained at 30°C. After 1 hour of reaction, the solution is heated to 60°C and the reaction is continued for 2 hours. The primary product is then filtered and washed repeatedly with deionized water and ethanol for 4 times to preliminarily form microcapsules. The obtained microcapsules are then placed in a drying oven at a constant temperature of 40°C and dried for 5 hours, and then weighed. Subsequently, they are placed in a drying oven at 60°C and dried for 2 hours, and then weighed. This operation is repeated to obtain magnetic self-healing capsules.

[0022] Example 2 Preparation of magnetic self-healing concrete

[0023] The raw materials are 180g of low-heat silicate cement, aggregate (320g of fine aggregate, 480g of coarse aggregate), 15g of nano carbon black: 300g of structural steel fiber, 30g of magnetic nano powder self-healing capsule, active admixture (65g of fly ash and silica fume), reinforcing agent (11.88g of silica fume, 3.11g of potassium lignosulfonate and 0.015g of sodium silicate), 10g of polycarboxylic acid high-performance water reducer, 120g of water, and 80g of emulsifier polyoxyethylene sorbitan monooleate (Tween-80)

[0024] 1) Aggregates (320 g fine aggregate, 480 g coarse aggregate) and emulsifier polyoxyethylene sorbitan monooleate (Tween-80) (80 g) are mixed, and water accounting for half of the total water volume (total amount 120 g) is added, and the mixture is stirred evenly; low-heat silicate cement (180 g) and reinforcing agent (11.88 g silica fume, 3.11 g potassium lignosulfonate and 0.015 g sodium silicate) are mixed, stirred evenly, and set aside for use;

[0025] 2) Mix the raw materials obtained in 1) and the remaining raw materials, add the remaining half of the water, put them into a small cement slurry mixer and mix them evenly, unload the materials, cast them into shape, remove the molds, and maintain them to obtain magnetic self-healing concrete.

[0026] Example 3 Magnetic self-healing concrete response loading device

[0027] The magnetic self-healing concrete response loading device includes a shell 1, a shell cover 2, a power supply system 3, a control system 4, and a telescopic module 5, a rotation module 6 and a magnetic field control module 7 which are all connected to the power supply system 3 and the control system 4; the telescopic module 5, the rotation module 6 and the magnetic field control module 7 are connected in sequence, the telescopic module 5 controls the telescopic movement of the magnetic field control module 7, and the rotation module 6 controls the rotation movement of the magnetic field control module 7.

[0028] Telescopic module 5 Figure 2As shown, it includes a slide rail 5-1, a pulley 5-2, a force plate 5-3, a first push rod 5-4, a movable shaft 5-5, a second push rod 5-6, a column 5-7, a turntable 5-8, a pulley 5-9, a belt 5-10, and a first motor 5-11; a pulley 5-9 is connected to the center of the bottom of the turntable 5-8, the output shaft of the motor 5-11 is connected to the pulley 5-9 by the belt 5-10, and a column 5-7 is provided on the edge of the upper surface of the turntable 5-8, one end of the second push rod 5-6 is rotatably connected to the column 5-7, and the other end is rotatably connected to the first push rod 5-4 through the movable shaft 5-5. When the motor 5-11 is working, it drives the turntable 5-8 to rotate, and the second push rod 5-6 rotatably connected to the column 5-7 moves accordingly, thereby causing the first push rod 5-4 to move up or down. The first push rod 5-4 of the driving assembly is fixedly connected to the force plate 5-3. The forward and backward movement of the force plate 5-3 drives the pulley 5-2 welded to the side of the force plate 5-3 to move forward and backward through the slide rail 5-1, thereby realizing the change in the size of the magnetic field provided by the device.

[0029] The rotating module includes a second motor, a rotating shaft 6 - 2 and a rotating block 6 - 1 , and the rotating block 6 - 1 is connected to the force applying plate 5 - 3 of the telescopic module 5 .

[0030] The magnetic field control module includes a circular disk, which is provided with a plurality of outer slide rails 7-1 outwardly from the center of the circle, and each outer slide rail is provided with a slidable small circular disk 7-2, and each small circular disk is provided with a plurality of inner slide rails 7-2-1 outwardly from the center of the circle, and each inner slide rail is provided with a slidable small magnet 7-2-2. There are 5 inner slide rails and 5 outer slide rails. Each small circular disk and the small magnet are connected to a telescopic device. The telescopic device has the same structure and principle as the telescopic module 5.

[0031] The working principle of the device of the present invention is as follows: the first telescopic module 5 realizes the forward and backward movement of the force plate 5-3 through the start of the motor 5-11, and the forward and backward positions are fixed by the slide rail 5-1; the rotating module 6 is welded to the telescopic module 5-3 and moves forward and backward, and the front magnetic field control and adjustment module 7 is driven to rotate and move forward and backward through the rotating shaft 6-2, so as to realize the effective strength of the direction and intensity of the magnetic field; the magnetic field dispersion module 7-2 and the small magnet 7-2-2 on the magnetic field control and adjustment module 7 realize the gathering and dispersion of the small magnet 7-2-2 through the outer slide rail 7-1 and the inner slide rail 7-2-1, so as to further effectively regulate the magnetic field intensity and direction provided by the device.

[0032] In the initial state, the crack of the magnetic self-healing concrete is detected, the response loading device is moved to the corresponding position, the shell cover 2 is opened, and the power supply system 3 is regulated by the control system 4 to supply power to the motors of different modules, and the device starts to run. The direction and intensity of the magnetic field provided by the response loading device of the magnetic micro-nano powder field response concrete are constantly changing. The magnetic self-healing capsules in the cracks with a tendency to crack but incomplete cracking are affected by the external dynamic magnetic field, and the static cracking is transformed into dynamic cracking, and its cracking efficiency is 2.5 times that of the original one. In addition, the adhesive flowing out of the capsule crack can also be disturbed by the dynamic magnetic field due to the magnetic powder components contained inside, and flows evenly in multiple directions, effectively filling the gaps, and greatly improving the repair effect of the self-healing concrete.

[0033] Example 4 Performance Comparison Test

[0034] The magnetic self-healing capsule prepared in Example 1 was used to obtain magnetic micro self-healing field responsive concrete according to the steps shown in Example 2. The magnetic micro-nano powder field responsive concrete was subjected to compression and flexural strength tests and repair rate tests, and the data obtained are shown in Table 1.

[0035] The magnetic micro-nano powder microcapsules prepared in Example 1 were used to obtain magnetic micro-nano powder field responsive concrete according to the steps shown in Example 2. The response loading device of the magnetic micro-nano powder field responsive concrete designed in the present invention was used to perform compressive strength, flexural strength and repair rate tests on the magnetic micro-nano powder field responsive concrete, and the data were as shown in Table 1. The traditional self-healing concrete was prepared according to the raw material mass of 180g low-heat silicate cement, aggregate (320g fine aggregate, 480g coarse aggregate), 15g nano carbon black: 300g structural steel fiber, 30g self-healing capsule, active admixture (65g each of fly ash and silica fume), reinforcing agent (11.88g silica fume, 3.11g potassium lignosulfonate and 0.015g sodium silicate), 10g polycarboxylic acid high-performance water reducer, 120g water, and 80g emulsifier polyoxyethylene sorbitan monooleate (Tween-80) according to Example 2 according to the same raw material ratio and the steps shown to obtain traditional self-healing concrete. The compressive strength, flexural strength and repair rate tests were carried out on the traditional self-healing concrete, and the data obtained are shown in Table 1.

[0036] Table 1 Performance test table

[0037]

[0038] After data comparison, that is, the performance data comparison between traditional self-healing concrete and magnetic micro-nano powder field response concrete under the action of response device, it can be seen that

[0039] The compressive strength of concrete mixed with magnetic micro-nano powder capsules reached 35.8MPa, which is not much different from the compressive strength of traditional self-healing concrete of 36.2MPa. This proves that the addition of magnetic powder has no significant effect on the strength of concrete. The new concrete has superior performance and good uniformity.

[0040] At the same time, by comparing the traditional self-healing concrete that cracked under the same conditions with the concrete added with magnetic micro-nano powder capsules, it can be found that its repair rate of 32.6% is nearly 1.5 times higher than the 24.2% of the traditional self-healing concrete, the flexural strength recovery rate and elastic modulus recovery rate are slightly improved, and the aging period is extended by 10%.

[0041] It can be seen that the concrete containing magnetic micro-nano powder capsules can still improve the healing degree of traditional self-healing concrete and increase its service life when used alone.

[0042] Under the action of the response device, the capsule rupture rate of the damaged concrete containing magnetic micro-nano powder capsules reached 75.1%, which was 3.6 times higher than the original 20.7%. The flexural strength recovery rate 48 hours after damage increased by nearly 2.3 times to 42.6%. The freeze-thaw cycle test or elastic modulus recovery rate was 54.3%, and the aging period was extended by more than 50%, which were significantly improved compared with traditional self-healing concrete.

[0043] It can be seen that in actual engineering applications, the combined use of a response loading device for magnetic micro-nano powder field-responsive concrete can greatly improve the repair efficiency of traditional self-healing concrete, and has little effect on physical properties such as compressive strength, and can meet the requirements of engineering applications.

Claims

1. A magnetic self-healing concrete response loading device, characterized in that: It includes a shell, a shell cover, a power supply system, a control system, and a telescopic module, a rotating module and a magnetic field control module which are all connected to the power supply system and the control system; the telescopic module, the rotating module and the magnetic field control module are connected in sequence, the telescopic module controls the telescopic movement of the magnetic field control module, and the rotating module controls the rotational movement of the magnetic field control module; the magnetic field control module includes a circular disk, the circular disk is provided with a plurality of outer slide rails outwardly with the center of the circle as the center, each outer slide rail is provided with a slidable small circular disk, each small circular disk is provided with a plurality of inner slide rails outwardly with the center of the circle as the center, and the inner slide rail is provided with a slidable small magnet; there are 5 inner slide rails and 5 outer slide rails, and each small circular disk and small magnet is connected with a telescopic device.

2. The response loading device according to claim 1, characterized in that: The telescopic module includes a slide rail, a pulley, a force plate, a first push rod, a movable shaft, a second push rod, a column, a turntable, a pulley, a belt and a first motor. The pulley is combined with the force plate by welding, and the slide rail is installed on the front and rear walls of the device. A pulley is connected to the center of the bottom of the turntable. The force plate is fixedly connected to the first push rod, and the output shaft of the motor is connected to the pulley by a belt. A column is provided on the edge of the upper surface of the turntable, and one end of the second push rod is rotatably connected to the column, and the other end is rotatably connected to the first push rod through a movable shaft.

3. The response loading device according to claim 2, characterized in that: The rotating module includes a second motor, a rotating shaft and a rotating block, and the rotating block is connected to the force application plate of the telescopic module.

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