Method for realizing bidirectional plate fiber orientation by using magnetic film material

Abstract

The present application relates to a kind of orientation method of two-way plate fiber using magnetic film material, mainly a kind of two-way plate fiber control method using magnetic film material applied to maintenance formwork concrete curing forming device, including the magnetic adsorption layer of soft magnetic material such as magnetic film material / silicon steel sheet, curing formwork, power supply, magnetization generator and the like composition of curing forming device.The curing forming device passes through " magnetic film " structure, on the one hand, vertical fiber is turned over during insertion process, on the other hand, when power is connected, magnetization generator generates magnetism, so that magnetic film adsorption layer obtains magnetism, and then the part of steel fiber in mixed slurry is acted, the uniformity of steel fiber dispersion in construction process is improved, the consistency of orientation.The device is simple, the scope of application is wide, the operation method is easy to operate, and it can be reused, the method can improve the mechanical properties of UHPC, innovate UHPC construction technology, and has great promoting significance for large-scale promotion and application of UHPC.

Description

Technical Field

[0001] Technical Field: This invention relates to the field of fiber-reinforced ultra-high performance concrete preparation technology, and in particular to a method and apparatus for the oriented curing and molding of ultra-high performance concrete fibers. Background Technology

[0002] Ultra-high performance concrete (UHPC) is a new type of material with ultra-high compressive strength and durability, designed based on the maximum bulk density theory. Due to its excellent mechanical properties and high durability, UHPC was first used in bridge decks and has gradually gained more attention and application in various construction fields. However, a large part of the limitation of UHPC is its cost, which is several times higher than that of ordinary concrete. About 80% of UHPC on the market uses steel fibers. Steel fibers improve the tensile and crack resistance of UHPC. The proportion of steel fibers in the cost of UHPC is 50% or more for most UHPCs. While the fiber contributes greatly to the performance of UHPC, it also brings high costs. Improving the fiber utilization rate is equivalent to reducing the cost of UHPC and greatly improving its competitiveness in the market.

[0003] Currently, fiber addition in construction typically involves directly adding the fiber to the slurry, mixing it, and then pouring it into a mold for molding, resulting in components with disordered fibers. Research on fiber-oriented casting methods is also limited. Some methods for improving fiber distribution are complex, cumbersome, time-consuming, and require skilled operators, hindering large-scale application and promotion. Therefore, there is an urgent need for an efficient and simpler method to improve the UHPC casting process. This invention proposes a manufacturing process to improve the fiber orientation within two-way slabs. This process is extremely simple to operate, has low requirements for the site environment and worker operating procedures, and is easy to implement and promote. Furthermore, the casting device used is lightweight and reusable. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention aims to propose a simple and easy-to-implement fiber orientation method for bidirectional plates with steel fibers. Compared with ordinary concrete pouring, the required pouring device only needs to add magnetic film material and power supply. The operation has basically no extra procedures, the operation difficulty is low, and the requirements for the working environment and operators are low.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for achieving fiber orientation in biaxially oriented slabs using magnetic film materials is characterized by: casting biaxially oriented slab components using a casting device containing a magnetic film adsorption layer; the contact between the magnetic film layer and the vertical fibers, and the attraction of the magnetic field generated by the magnetic film material to the steel fibers, altering the directional distribution of the steel fibers in the curing device; by adding a magnetic adsorption layer to the curing device, the internal fiber orientation is controlled, ensuring that the original casting process and technology are not significantly altered, making it convenient for casting personnel to use and adaptable to most curing environments.

[0007] Magnetic thin film materials are strongly magnetic (ferromagnetic and ferrimagnetic) materials with a thickness of less than 1 micrometer. They broadly include ferrite, perovskite, single-layer metal alloy films, and metal / oxide films, and are currently widely used in information storage, stealth technology, magnetic sensors, microwave communication, electronic countermeasures, and electromagnetic compatibility. Soft magnetic materials can achieve maximum magnetization with minimal external magnetic field strength. They are easy to magnetize and demagnetize, and silicon steel sheets and various soft magnetic ferrites are among the most widely used soft magnetic materials. Based on the easy magnetization and demagnetization characteristics of soft magnetic materials, and by reducing their thickness, they can be applied to the magnetic adsorption layer of curing devices. This allows for effective controllable adsorption of fibers, and due to their thinness, has minimal impact on the slurry. Considering the economic benefits of optimizing the destination of soft magnetic materials and fibers, the magnetic film material can be used to adsorb fibers, and then alternately layered as the magnetic adsorption layer and slurry for simplified slurry casting.

[0008] To ensure the magnetization control performance of the magnetic thin film material, grooves are used to control the position of the magnetic adsorption layer, while a power supply and a magnetization generator are used to make the magnetic adsorption layer magnetic.

[0009] Preferably, the thickness of the magnetic adsorption layer should be less than 1 mm, so as to reduce the impact on the poured slurry and prevent the phenomenon of insufficient pouring.

[0010] Preferably, the magnetic adsorption layer should have a small thickness while ensuring sufficient rigidity.

[0011] Preferably, the magnetic adsorption layers are fixed together using bolts and bolt plates, which facilitates operation and reduces the time and manpower required for pouring.

[0012] Preferably, the device can be powered by a portable power source such as a battery, thereby reducing the device's environmental requirements.

[0013] Preferably, the spacing between adjacent magnetized adsorption layers should be less than three times the length of the steel fiber, and at the same time, it should be greater than the maximum coarse aggregate particle size, more than 1 cm.

[0014] In particular, for certain special components or where the curing environment is limited, a batch of fibers can be directionally adsorbed using magnetic film material first, and then the magnetic film material layer-slurry layer-magnetic film material layer can be poured in sequence. That is, during the pouring process, a layer of magnetic film material with adsorbed fibers is added every certain height, and this magnetic film material layer is directly left in the cast structural component.

[0015] In particular, if the above-mentioned casting method of not removing the magnetic adsorption layer is adopted, the thickness of the magnetic adsorption layer should be less than 0.1 mm, and a porous magnetic adsorption layer structure should be adopted to reduce the impact on the vertical bearing capacity of the structure.

[0016] The fiber orientation method provided by this invention offers a new approach to controlling fiber direction in the casting and arching of biaxial slabs, which is of great significance for further promoting the application of UHPC.

[0017] The beneficial effects of the present invention through the above technical solution are:

[0018] For two-way slab components commonly used in engineering, UHPC incorporating steel fibers is used. The fiber orientation is adjusted, primarily reducing the proportion of vertical fibers, thereby increasing fiber utilization and lowering fiber-related costs. Compared to previous technologies, this method is adaptable to most pouring, curing, and construction environments. The pouring time and personnel skill requirements are not increased compared to existing technologies. It is simple and easy to operate, and the magnetized adsorption layer can be reused when not used as a permanent formwork, resulting in low cost. Attached Figure Description

[0019] Figure 1 Overall schematic diagram of the magnetic film material curing template device

[0020] Figure 2 Detailed diagram of the groove in the maintenance template

[0021] Figure 3 Schematic diagram of magnetic adsorption layer

[0022] Figure 4 Schematic diagram of magnetic adsorption layer

[0023] Explanation of icon numbers:

[0024] 1. Power supply, 2. Magnetic adsorption layer, 3. Connecting layer, 31. Bolt hole, 32. Bolt, 33. Bolt plate, 4. Curing device, 41. Mixed slurry, 42. Curing template, 43. Template splicing groove, 44. Magnetic adsorption layer groove, 45. Reserved groove, 5. Magnetization generator, 51. Insert plate, 6. Steel fiber. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This embodiment describes a casting device and process for controlling the internal steel fiber distribution and orientation of UHPC-cast two-way slabs, increasing the proportion of horizontally distributed steel fibers, thereby improving fiber utilization and reducing component costs. For two-way slabs, bending is the primary load, leading to vertical cracks. The presence of fibers allows them to penetrate these micro-cracks. When micro-cracks appear, the tensile strength of the fibers and their adhesion to the grout act as a bridge, thus inhibiting cracking. Since the ultimate failure of slab components is primarily due to bending, resulting in vertical cracks and subsequent damage, this means that to improve fiber utilization, the proportion of horizontally distributed steel fibers should be increased, allowing more fibers to appear between micro-cracks, thereby improving crack resistance, load-bearing capacity, and other properties.

[0027] like Figure 1-3 As shown, a method for achieving fiber orientation in biaxially oriented slabs using magnetic film materials is characterized by a casting device comprising a magnetic adsorption layer 2 composed of a magnetic film material or a soft magnetic material such as silicon steel sheet, a curing template 4, a power supply 1, a connecting layer 3 connecting all magnetic adsorption layers to facilitate the casting process, and a magnetization generator 5 controlling the generation and demagnetization of magnetism. The curing template 4 has grooves 44 on its side molds for the entry and exit of the magnetic adsorption layer 2, and also has splicing slots 43 for connecting the bottom mold and other side molds. A pre-reserved groove 45 is provided on the edge of the side mold connected to the magnetized adsorption layer for inserting a baffle as a slurry curing template after the magnetic adsorption layer is removed.

[0028] Preferably, for precast plants using templates for multiple pours, the pre-reserved groove 45 is not required. After the magnetic adsorption layer 2 is pulled out, a locking mechanism is set so that the side of the magnetic adsorption layer becomes part of the template, thereby preventing grout leakage.

[0029] Furthermore, the template connected to the magnetic adsorption layer should ideally be manufactured as a single unit with the magnetic adsorption layer. Holes corresponding to the thickness of the magnetic adsorption layer should be pre-drilled in the template.

[0030] Furthermore, either a plug-in power supply or a portable power supply can be used to facilitate the pouring process on-site.

[0031] Furthermore, plug plates should be installed at the edges of both magnetizers to connect to the power supply and enable the magnetizers to operate.

[0032] Furthermore, the connecting layer is designed as a combination of bolt plates and bolts with pre-drilled bolt holes, which is used to connect several magnetic adsorption layers into a whole. During the pouring process, it is not necessary to move the magnetic adsorption layers one by one, thereby improving the ease of use.

[0033] Furthermore, if the magnetic adsorption layer is to remain inside the component, the magnetic adsorption layer should preferably be in the form of internal pores to improve the interaction force between the slurry layers. At this time, the thickness of the magnetic adsorption layer should be further reduced. If this method is adopted, there is no need to do the above treatment on the curing template. Ordinary curing templates can be used. It is only necessary to lay the "fiber magnetic film" with adsorbed fibers and the mixed slurry layer by layer.

[0034] Example 1:

[0035] refer to Figure 1-4 The specific construction steps are as follows:

[0036] Step 1: Determine the required size and thickness of the two-way board, customize the corresponding size template, complete the splicing and assembly, and brush oil on the inside to facilitate subsequent demolding.

[0037] Step 2: First, pull out the magnetic adsorption layer 2 by directly moving the connecting layer 3 until the clamp is locked in the gap on the template. Then, pour the mixed slurry into the curing template 4 until the surface is basically poured and smooth the surface.

[0038] Step 3: Controlling the position of the connecting layer 3, the magnetic adsorption layer 2 is fully inserted into the template 4. During this process, the vertical fibers are acted upon, causing them to rotate. Simultaneously, the power supply 1 activates the magnetization generator 5 via the insert plate 51. The magnetization generator generates magnetism and magnetizes the magnetic adsorption layer 2, which is composed of soft magnetic material inside. The steel fibers in the curing slurry are influenced by the magnetic force of the magnetic adsorption layer, moving towards the magnetic adsorption layer and rotating, thus adhering to the surface of the magnetic adsorption layer.

[0039] Step 4: Unplug the plug at the insertion plate 51, and also pull the magnetic adsorption layer 2 out of the template until it reaches the bayonet, and use it as a side mold for maintenance.

[0040] Step 5: Lay a film on the surface of the device to prevent moisture evaporation. After curing for a certain period of time, remove the mold and take out the components to the construction site or hoist them to the designed location.

[0041] Example 2:

[0042] Only when the cost of the magnetic film material is lower than the cost reduction of the fiber due to adjusting the fiber orientation can the magnetic film material be considered as one of the structures permanently retained inside the component. In this method, the magnetic film layer needs to have fine pores to prevent the fibers from separating from the slurry and to ensure the fiber bridging effect.

[0043] Step 1: Determine the required size and thickness of the two-way board, customize the corresponding size template, complete the splicing and assembly, and brush oil on the inside to facilitate subsequent demolding.

[0044] Step 2: Pour in the mixed, fiber-free UHPC slurry. Every 5mm of slurry poured, place the fiber-adsorbed "fiber magnetic membrane" inside. Continue pouring slurry, repeating this process until the surface is full. This step can be precisely controlled by machine in the prefabrication plant.

[0045] Step 3: Lay a film on the surface of the device to prevent moisture evaporation. After curing for a certain period of time, remove the mold and take out the components to the construction site or hoist them to the designed location.

Claims

1. A method of achieving bidirectional panel fiber orientation with a magnetic film material, the method comprising: The method comprises the following steps: a) setting grooves and reserved slots for the magnetic adsorption layer to enter and exit on the side mold of the two-way plate maintenance template, connecting multiple magnetic adsorption layers into one by connecting layers and bolts, so as to move integrally during pouring, wherein the magnetic adsorption layer is made of magnetic film material or silicon steel sheet, and the thickness is less than 1 mm; b) after pouring and smoothing the UHPC slurry containing steel fibers into the template, controlling the connecting layer to insert the multiple magnetic adsorption layers integrally into the slurry, wherein the spacing between adjacent magnetic adsorption layers is less than three times the length of the steel fiber and greater than the maximum coarse aggregate particle size, and is not less than 1 cm, so that the vertical steel fiber rotates during contact with the magnetic adsorption layer; c) magnetizing the magnetic adsorption layer by driving the magnetization generator through the power supply, so that the steel fiber in the slurry moves towards the magnetic adsorption layer under the action of magnetic force; then, the magnetic adsorption layer is demagnetized by power-off, and is pulled out integrally for curing.

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