Composite aluminum alloy formwork and aluminum alloy mold for curing concrete

Abstract

This invention discloses a unidirectional thermal insulation and permeable membrane and its preparation method, and also discloses a composite aluminum alloy template, including an aluminum alloy panel, an aluminum alloy back plate, and multiple end ribs; the aluminum alloy panel and the aluminum alloy back plate are arranged opposite each other and connected; multiple drainage holes are opened on the aluminum alloy panel; the outer surface of the aluminum alloy panel is fully covered with a unidirectional thermal insulation and permeable membrane, which includes a hydrophilic layer, a thermal insulation layer, and a hydrophobic layer arranged sequentially, wherein the hydrophilic layer is attached to the outer surface of the aluminum alloy panel. This invention also discloses an aluminum alloy mold for concrete curing. The beneficial effects of this invention are: the composite aluminum alloy template has a cavity covered with a unidirectional thermal insulation and breathable membrane, which drains the water that accumulates on the surface of the aluminum alloy panel after pouring and vibration, reduces the water-cement ratio of the concrete surface, strengthens the hydration reaction of the concrete surface components, reduces the apparent porosity of the concrete, improves the appearance quality of the concrete, and enhances the rebound strength of the specimen.

Description

Technical Field

[0001] This invention relates to the field of concrete curing technology, specifically to a composite aluminum alloy template and an aluminum alloy mold for concrete curing. Background Technology

[0002] With the rapid development of the construction industry, concrete is widely used in various fields, and various types of concrete with different functions have emerged. Aluminum alloy formwork is a type of construction formwork that has become popular in recent years. Its main characteristics are high strength, light weight, good stability, simple construction, and energy saving and environmental protection.

[0003] However, aluminum alloy formwork also has the following main problems: On the one hand, because aluminum alloy formwork has good airtightness and is non-absorbent, excess water in the concrete, in addition to the hydration reaction, accumulates on the surface of the formwork, and air bubbles generated during concrete vibration cannot be expelled, resulting in whitening of the concrete surface and the appearance of a large number of air bubbles; on the other hand, because aluminum alloy formwork has a high thermal conductivity, heats up quickly, and has poor heat preservation capacity, it leads to different degrees of hydration inside and outside the concrete, resulting in lower concrete surface strength. At the same age, the rebound strength is lower than that of wooden formwork and steel formwork. Therefore, the presence of air holes and low rebound strength on the surface of concrete cured with aluminum alloy formwork has become an urgent problem to be solved in current engineering construction. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a unidirectional heat-insulating and water-permeable membrane and its preparation method, a composite aluminum alloy template, and an aluminum alloy mold for concrete curing, aiming to solve the problems of air holes and low rebound strength on the surface of concrete cured by existing aluminum alloy templates.

[0005] The technical solution adopted in this invention is as follows: a one-way heat-insulating and water-permeable membrane, comprising a hydrophilic layer, a heat-insulating layer and a hydrophobic layer arranged sequentially. The hydrophilic layer is a nanoscale fiber membrane made of a polymer obtained by mixing polyacrylamide, polyacrylamide and cellulose acetate; the heat-insulating layer is a micron-scale green heat-insulating fiber membrane made of a polymer obtained by mixing ultrafine alumina, ultrafine aluminum silicate, lignin cellulose, reed fiber and hemicellulose; and the hydrophobic layer is a micron-scale fiber membrane made of a polymer obtained by mixing polyacrylonitrile, polycarbonate, polycaprolactone and poly(p-phenylene terephthalamide).

[0006] According to the above scheme, the mass ratio of polyacrylamide, polyacrylamide, and cellulose acetate in the hydrophilic layer is (2.5-3.3):(1.8-3.0):1.5.

[0007] According to the above scheme, the mass ratio of ultrafine alumina, ultrafine aluminum silicate, lignin cellulose, reed fiber, and hemicellulose in the insulation layer is (1.6~2.4):(0.8~1.6):(3.1~3.8):(2.6~3.4):2.

[0008] According to the above scheme, the mass ratio of polyacrylonitrile, polycarbonate, polycaprolactone, and poly(p-phenylene terephthalamide) in the hydrophobic layer is 1:(1.7-2.5):(1.9:2.5):(2.1-2.8).

[0009] The present invention also provides a method for preparing the unidirectional heat-insulating and water-permeable membrane as described above, the method being:

[0010] Step 1: Prepare solvents for the hydrophilic layer, the insulating layer, and the hydrophobic layer respectively;

[0011] Step 2: Dissolve the components of the hydrophilic layer, thermal insulation layer, and hydrophobic layer in their respective solvents to obtain the corresponding spinning solutions:

[0012] Step 3: Prepare a hydrophilic layer, a thermal insulation layer, and a hydrophobic layer using a spinning solution to obtain a one-way thermally permeable membrane: Place the electrospinning solution corresponding to the hydrophilic layer into the syringe of an electrospinning device. Apply a high-voltage electrostatic field between the syringe and the receiving substrate. The applied high-voltage electrostatic field causes the polymer electrospinning solution to generate a jet under electrostatic action, resulting in a corresponding randomly arranged fiber membrane, i.e., the hydrophilic layer, on the receiving substrate. Prepare a micron-sized fiber membrane using the thermal insulation layer material and uniformly cover it on the surface of the receiving substrate composed of the nanoscale fiber membrane prepared from the hydrophilic layer material. Prepare a micron-sized fiber membrane using the hydrophobic layer material and uniformly cover it on the surface of the receiving substrate composed of the micron-sized membrane prepared from the thermal insulation layer material to form a one-way permeable thermal insulation membrane.

[0013] According to the above scheme, the solvent for the hydrophilic layer is a mixture of deionized water, anhydrous ethanol, analytical grade ethylene glycol, and analytical grade acetone, with a mass ratio of 1.5:1:1:1; the solvent for the insulation layer is a mixture of deionized water, sodium lignosulfonate, sodium hydroxide, and pyridine, with a mass ratio of 2:1:0.5:1.5; and the solvent for the hydrophobic layer is a mixture of dimethyl sulfoxide, carbon tetrachloride, and isopropyl acetate, with a mass ratio of 2:2:1.

[0014] According to the above scheme, analytically pure hydrophilic layer polymers are dissolved in corresponding solvents at room temperature (20–25°C) and stirred thoroughly until the polymers are completely dissolved to obtain an electrospinning solution of the hydrophilic layer polymer, with the resulting solution containing 10–40% polymer by mass. Analytically pure thermal insulation material is dissolved in corresponding solvents at room temperature (20–25°C) and stirred thoroughly until the material is completely dissolved to obtain an electrospinning solution of the thermal insulation material, with the resulting solution containing 15–45% thermal insulation material by mass. Analytically pure hydrophobic layer polymers are dissolved in corresponding solvents at room temperature (20–25°C) and stirred thoroughly until the polymers are completely dissolved to obtain an electrospinning solution of the hydrophobic layer polymer, with the resulting solution containing 10–35% polymer by mass.

[0015] The present invention also provides a composite aluminum alloy template, including an aluminum alloy panel, an aluminum alloy back plate, and multiple end ribs; the aluminum alloy panel and the aluminum alloy back plate are arranged opposite each other and connected, and their edges are enclosed and fixed by multiple end ribs to form a template with an internal cavity; multiple drainage holes are provided on the aluminum alloy panel; the outer surface of the aluminum alloy panel is fully covered with a one-way heat-insulating and water-permeable membrane as described above, the one-way water-permeable and heat-insulating membrane including a hydrophilic layer, a heat-insulating layer and a hydrophobic layer arranged in sequence, wherein the hydrophilic layer is attached to the outer surface of the aluminum alloy panel.

[0016] According to the above scheme, the end ribs are evenly distributed with threaded holes of the same size, the threaded holes are straight through the rectangular groove of the aluminum alloy panel, and bolts are installed on the threaded holes; the outer side of the aluminum alloy back plate is provided with two secondary ribs.

[0017] The present invention also provides an aluminum alloy mold for concrete curing, comprising five composite aluminum alloy templates as described above. The five composite aluminum alloy templates are respectively set at the bottom and four sides, forming a pouring cavity with a top opening. Concrete is poured into the pouring cavity. The aluminum alloy panels of each composite aluminum alloy template face into the pouring cavity, and a release agent is evenly applied to the hydrophobic layer of the unidirectional heat-insulating and water-permeable membrane.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The composite aluminum alloy template of the present invention has a cavity, drainage holes in the panel, and is covered with a one-way heat-insulating and breathable membrane. The one-way heat-insulating and water-permeable membrane in this application has an insulation layer added between the hydrophobic layer and the hydrophilic layer, so that the water-permeable membrane has both drainage and heat-insulating functions. By utilizing the synergistic effect of the two, on the one hand, the water that has accumulated on the surface of the aluminum alloy panel after pouring and vibration can be drained, reducing the water-cement ratio of the concrete surface, strengthening the hydration reaction of the concrete surface components, reducing the apparent porosity of the concrete, improving the appearance quality of the concrete, and increasing the rebound strength of the specimen; on the other hand, the water flows into the cavity of the composite aluminum alloy template through the drainage holes, forming a heat-insulating barrier, which can reduce the heat conduction in the hydration of the concrete, ensure the stability of the internal and external curing temperature of the concrete, and have a good effect on the increase of the rebound strength of the concrete specimen; furthermore, the cavity of the composite aluminum alloy template stores water, which has a good moisturizing effect, ensuring the hydration process of the concrete and improving the surface strength of the concrete. In addition, when a one-way thermal insulation and permeable membrane comes into contact with concrete, it can absorb light substances, carbon powder, oil stains and other impurities brought by the raw materials themselves, but it is easy to dissolve and can be recycled.

[0020] (2) The unidirectional heat-insulating and water-permeable membrane of the present invention can transport the water accumulated on the surface of the aluminum alloy panel out in one direction through the membrane, thereby reducing the accumulation of excess water on the surface of the aluminum alloy panel; on the other hand, the membrane itself has a heat-insulating layer in the middle, which can effectively reduce the heat conduction of concrete. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the composite aluminum alloy template in this invention.

[0022] Figure 2 This is a front view of the composite aluminum alloy template of the present invention.

[0023] Figure 3 This is a rear view of the composite aluminum alloy template of the present invention.

[0024] Figure 4 This is the bolt structure of the composite aluminum alloy template of the present invention.

[0025] Figure 5 This is a schematic diagram of the overall structure of the aluminum alloy mold in this invention.

[0026] Figure 6 This is a schematic diagram of the concrete, one-way thermal insulation and permeable membrane, and composite aluminum alloy formwork in this invention.

[0027] Among them, 1-aluminum alloy panel, 2-end rib, 3-secondary rib, 4-drainage hole, 5-pin hole, 6-bolt, 7-composite aluminum alloy template, 8-concrete, 9-hydrophilic layer, 10-insulation layer, 11-hydrophobic layer, 12-aluminum alloy back plate; 13-release agent. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to specific embodiments, but it should not be construed as limiting the scope of the present invention to the following examples.

[0029] like Figure 6 The one-way heat-insulating and water-permeable membrane shown is characterized by comprising a hydrophilic layer 9, a heat-insulating layer 10, and a hydrophobic layer 11 arranged sequentially.

[0030] Preferably, the hydrophilic layer 9 is a nanofiber membrane made of a polymer obtained by mixing polyacrylamide, polyacrylamide and cellulose acetate, with a fiber diameter of 200-700 nm and a thickness of 30-40 μm; wherein the mass ratio of polyacrylamide, polyacrylamide and cellulose acetate is (2.5-3.3):(1.8-3.0):1.5.

[0031] Preferably, the insulation layer 10 is a micron-sized green insulation fiber membrane made of a polymer obtained by mixing ultrafine alumina, ultrafine aluminum silicate, lignin cellulose, reed fiber, and hemicellulose. The thickness of the micron-sized green insulation fiber membrane is 20μm to 30μm, and the fiber diameter is 2μm to 4μm. The mass ratio of ultrafine alumina, ultrafine aluminum silicate, lignin cellulose, reed fiber, and hemicellulose is (1.6 to 2.4): (0.8 to 1.6): (3.1 to 3.8): (2.6 to 3.4): 2.

[0032] Preferably, the hydrophobic layer 11 is a micron-sized fiber membrane made of a polymer obtained by mixing polyacrylonitrile, polycarbonate, polycaprolactone, and poly(p-phenylene terephthalamide), with a thickness of 10 μm to 20 μm and a fiber diameter of 1 μm to 4 μm; the mass ratio of polyacrylonitrile, polycarbonate, polycaprolactone, and poly(p-phenylene terephthalamide) is 1:(1.7 to 2.5):(1.9:2.5):(2.1 to 2.8).

[0033] In this invention, the single-layer heat-insulating and water-permeable membrane is prepared using electrospinning technology. The specific preparation method includes the following steps:

[0034] Step 1: Prepare solvents for the hydrophilic layer 9, the thermal insulation layer 10, and the hydrophobic layer 11, respectively.

[0035] The hydrophilic layer 9 is a solvent composed of deionized water, anhydrous ethanol, analytical grade ethylene glycol, and analytical grade acetone, with a mass ratio of 1.5:1:1:1. The insulating layer 10 is a solvent composed of deionized water, sodium lignosulfonate, sodium hydroxide, and pyridine, with a mass ratio of 2:1:0.5:1.5. The hydrophobic layer 11 is a solvent composed of dimethyl sulfoxide, carbon tetrachloride, and isopropyl acetate, with a mass ratio of 2:2:1. The components of the hydrophilic layer 9, insulating layer 10, and hydrophobic layer 11 are dissolved in their respective solvents to obtain the corresponding spinning solutions.

[0036] Step 2: Dissolve the components of the hydrophilic layer 9, the thermal insulation layer 10, and the hydrophobic layer 11 in their respective solvents to obtain the corresponding spinning solutions:

[0037] Analytical grade hydrophilic layer 9 polymer was dissolved in a corresponding solvent at room temperature (20–25°C) and stirred thoroughly until the polymer was completely dissolved to obtain an electrospinning solution of hydrophilic layer 9 polymer, with a polymer mass fraction of 10–40%. Analytical grade thermal insulation layer 10 material was dissolved in a corresponding solvent at room temperature (20–25°C) and stirred thoroughly until the material was completely dissolved to obtain an electrospinning solution of thermal insulation layer 10 material, with a thermal insulation material mass fraction of 15–45%. Analytical grade hydrophobic layer 11 polymer was dissolved in a corresponding solvent at room temperature (20–25°C) and stirred thoroughly until the polymer was completely dissolved to obtain an electrospinning solution of hydrophobic layer 11 polymer, with a polymer mass fraction of 10–35%.

[0038] Step 3: Prepare the hydrophilic layer 9, the thermal insulation layer 10, and the hydrophobic layer 11 using a spinning solution:

[0039] The electrospinning solution corresponding to the hydrophilic layer 9 is placed in the syringe of the electrospinning equipment. A high-voltage electrostatic field is applied between the syringe and the receiving substrate. The voltage of the high-voltage electrostatic field is 10-30KV. The distance between the metal spinneret and the receiving substrate is adjusted to 10-30cm. The applied high-voltage electrostatic field causes the polymer electrospinning solution to generate a jet under electrostatic action, and the corresponding randomly arranged fiber membrane, i.e., the hydrophilic layer 9, is obtained on the receiving substrate.

[0040] A microfiber membrane is prepared using insulation layer 10 material and uniformly coated onto the surface of a receiving substrate composed of a nanofiber membrane prepared using hydrophilic layer 9 material. A microfiber membrane is also prepared using hydrophobic layer 11 material and uniformly coated onto the surface of the receiving substrate composed of a microfiber membrane prepared using insulation layer 10 material. Any two adjacent fiber membrane layers are tightly connected to form a one-way permeable and heat-insulating membrane. The receiving substrate of the hydrophilic layer 9 is a 40-300 mesh steel wire mesh.

[0041] In this invention, the one-way permeable thermal insulation membrane has hydrophilic, thermal insulation and hydrophobic properties. Water enters from the hydrophobic layer 11 side of the one-way permeable thermal insulation membrane, passes through the thermal insulation layer 10, and passes through the hydrophilic layer 9 side, but water cannot enter from the hydrophilic layer 9, penetrate the thermal insulation layer 10 and pass through the hydrophobic layer 11; the one-way permeable thermal insulation membrane also prevents cement slurry particles from passing through.

[0042] like Figures 1-3 The composite aluminum alloy template 7 shown includes an aluminum alloy panel 1, an aluminum alloy back plate 12, and multiple end ribs 2; the aluminum alloy panel 1 and the aluminum alloy back plate 12 are arranged opposite each other and connected, and their edges are enclosed and fixed by multiple end ribs 2 to form a template with an internal cavity; multiple drainage holes 4 are provided on the aluminum alloy panel 1; the outer surface of the aluminum alloy panel 1 is fully covered with a one-way heat-insulating and water-permeable membrane, the one-way water-permeable and heat-insulating membrane includes a hydrophilic layer 9, a heat-insulating layer 10 and a hydrophobic layer 11 arranged in sequence, wherein the hydrophilic layer 9 is attached to the outer surface of the aluminum alloy panel 1.

[0043] In this invention, the composite aluminum alloy template 7 is rectangular in shape and includes four end ribs 2. Two secondary ribs 3 are provided on the outer side of the aluminum alloy back plate 12 to improve the overall strength of the composite aluminum alloy template 7. The side end ribs 2 are provided with evenly distributed pin holes 5 for easy assembly. They are the same size and symmetrical to each other and are used to connect different templates. The top end ribs 2 are provided with evenly distributed threaded holes of the same size for drainage.

[0044] In this invention, the aluminum alloy panel 1 has a plurality of drainage holes 4 arranged in a uniform array, the diameter of which is 1-2 mm; the aluminum alloy panel 1 has a certain thickness and is hollow, with a rectangular groove in the middle, the length and width of which are the same as those of the aluminum alloy panel 1, and the thickness is one-third of that of the aluminum alloy panel 1, forming a template with a cavity together with the aluminum alloy back plate 12; the edge of the aluminum alloy panel 1 is provided with end ribs 2, and the top end ribs 2 are evenly distributed with threaded holes of the same size, the threaded holes leading directly to the rectangular groove of the aluminum alloy panel 1, and bolts 6 (such as...) are disposed on the threaded holes. Figure 4 As shown), the moisture in the inner cavity of the template is drained by installing and removing bolts 6; the back of the aluminum alloy back plate 12 is provided with secondary ribs 3 to improve the strength of the entire composite aluminum alloy template 7.

[0045] like Figure 5 The aluminum alloy mold for concrete curing shown includes five composite aluminum alloy templates 7 as described above. The five composite aluminum alloy templates 7 are respectively set at the bottom and four sides, and are connected to form a pouring cavity with a top opening. Concrete 8 is poured into the pouring cavity. The aluminum alloy panel 1 of each composite aluminum alloy template 7 faces into the pouring cavity, and the surface of the one-way heat-insulating and water-permeable membrane (i.e., the hydrophobic layer 11) is evenly coated with a release agent 13 (specifically, it can be an emulsified oil release agent 13).

[0046] In this invention, from the inside out, there are concrete 8, one-way heat-insulating and water-permeable membrane, aluminum alloy panel 1, and aluminum alloy back plate 12.

[0047] In this invention, such as Figure 6 As shown, the aluminum alloy mold containing concrete 8 consists of, from the inside out, concrete 8, 13 layers of release agent, 11 hydrophobic layer of unidirectional thermal insulation and permeable membrane, 10 thermal insulation layer of unidirectional thermal insulation and permeable membrane, 9 hydrophilic layer of unidirectional thermal insulation and permeable membrane, aluminum alloy panel 1, and aluminum alloy back plate 12.

[0048] The working principle of this invention is as follows: Concrete 8 is poured into the aluminum alloy mold. After the concrete 8 is poured and vibrated, water in the concrete 8 accumulates on the surface. Then, the water enters the hydrophobic layer 11 of the one-way heat-insulating and water-permeable membrane through the release agent layer 13, passes through the heat-insulating layer 10 of the one-way heat-insulating and water-permeable membrane, and flows out from the hydrophilic layer 9 side of the one-way heat-insulating and water-permeable membrane. After passing through the drainage hole 4 on the aluminum alloy panel 1, it flows into the cavity of the composite aluminum alloy template 7. On the one hand, after the water flows into the cavity of the composite aluminum alloy template 7, it forms a barrier, which can effectively reduce the heat dissipation of the composite aluminum alloy template 7 and ensure the temperature stability of the concrete system inside the composite aluminum alloy template 7. On the other hand, the water remains in the composite aluminum alloy template 7, providing a certain humidity to the concrete 8, which is beneficial to improving the surface strength of the concrete 8.

[0049] The composite aluminum alloy formwork 7 of this invention has a cavity inside, drainage holes 4 on the panel, and is covered with a one-way heat-insulating and breathable membrane. On the one hand, it can drain the water that accumulates on the surface of the aluminum alloy panel 1 after pouring and vibration, reducing the water-cement ratio on the surface of the concrete 8, strengthening the hydration reaction of the surface components of the concrete 8, and reducing the apparent porosity of the concrete 8, thus improving the appearance quality of the concrete 8. On the other hand, the water flows into the cavity of the composite aluminum alloy formwork 7 through the drainage holes 4, forming a heat insulation barrier, which can reduce the heat conduction during the hydration of the concrete 8, ensure the stability of the internal and external curing temperature of the concrete 8, and play a good role in the strength growth of the concrete 8. Furthermore, the water storage in the cavity of the composite aluminum alloy formwork 7 has a good moisturizing effect, ensuring the hydration process of the concrete 8 and improving the surface strength of the concrete 8.

[0050] The raw materials used in the embodiments and comparative examples are as follows:

[0051] Concrete preparation materials: P·O42.5R ordinary Portland cement, fly ash, sand (fineness modulus of 2.8, apparent density of 2707 kg / m³). 3 The bulk density is 1658 kg / m³. 3 ), crushed stone (crushed stone with a particle size of 5-25mm), fine stone (crushed stone with a particle size of 5-10mm), and admixtures (common admixtures are sufficient).

[0052] Release agent 13: Xibian water-in-oil release agent 13, Xinkete oil-in-water release agent 13.

[0053] One-way thermal insulation and water permeable membrane: The mass ratio of polyacrylamide, polyacrylamide and cellulose acetate in hydrophilic layer 9 is 3:2.5:1.5; the mass ratio of ultrafine alumina, ultrafine aluminum silicate, lignin cellulose, reed fiber and hemicellulose in thermal insulation layer 10 is 2:1:3.5:3:2; the mass ratio of polyacrylonitrile, polycarbonate, polycaprolactone and poly(p-phenylene terephthalamide) in hydrophobic layer 11 is 1:2:2:2.5.

[0054] 20. Implementation Methods

[0055] 1) Prepare concrete using cement, fly ash, sand, fine sand, etc., and pour the pre-mixed concrete into the aluminum alloy mold in layers. Divide the concrete into multiple vibration points according to the vibration spacing. Use a quick insertion and slow withdrawal method for vibration. Set the vibration time for each point to 10-12 seconds. After molding, cure for 48 hours before demolding.

[0056] 2) Place the demolded and cured concrete specimens on a platform at a certain height. Use a high-resolution SLR camera to capture images of the concrete surface, taking pictures of all four sides of the specimen. Subsequently, use software such as Image-Pro-Plus to process and analyze the images (analyzing all four sides of each specimen and summarizing the results) to detect the number and area of ​​pores on the concrete surface for the same area.

[0057] 3) After taking photos, the concrete specimens were placed under natural curing conditions and their rebound strength was tested after 28 days.

[0058] Example 1

[0059] The aluminum alloy mold for concrete curing described in this invention is used to cure concrete, and the performance of the concrete is tested. The specific construction method is as follows:

[0060] Provide the aluminum alloy mold and complete the installation preparation. Apply Xibian water-in-oil release agent 13 in advance. Conduct concrete test mix according to the mix ratio in Table 1. The slump / spread of the concrete is 230mm / 520mm. Conduct the test according to the test method in the above implementation method.

[0061] Table 1 Concrete Mix Proportions

[0062] C40 300 80 920 840 100 7.3 152

[0063] Comparative Examples 1 to 3 were prepared using different molds for concrete curing, and the concrete performance was tested.

[0064] The difference between Comparative Example 1 and Example 1 is that the template is a non-perforated aluminum mold of the same size and dimensions commonly used on construction sites, and the aluminum mold is formed by enclosing a single aluminum template.

[0065] The difference between Comparative Example 2 and Example 1 is that the template used is a concrete wooden mold of the same size and dimensions commonly used on construction sites.

[0066] The difference between Comparative Example 3 and Example 1 is that the template used is a concrete steel mold of the same size and dimensions commonly used on construction sites.

[0067] The test results of Example 1 and Comparative Examples 1-3 are shown in Table 2 below.

[0068] Table 2 Performance test parameters of the examples and comparative examples

[0069]

[0070] As can be seen from Table 2, the concrete performance using the curing system of this invention is superior to that of the curing system used in engineering projects. The specific comparison is as follows:

[0071] (1) Comparing the data of Example 1 and Comparative Example 1 in the table, it can be seen that the concrete rebound strength under the aluminum formwork curing system of the present invention is higher than that of the commonly used aluminum formwork system in engineering. The corresponding apparent pores of the concrete are much less than those under the commonly used aluminum formwork system in engineering. The aluminum formwork curing system of the present invention has both heat preservation and drainage functions. While reducing excess moisture and air bubbles on the concrete surface, it also reduces the heat loss of the concrete during construction, further ensuring higher apparent density of the concrete. It reduces the difference between the rebound strength of the concrete specimen and the strength of the actual structure, while improving the apparent quality of the concrete, and greatly improves the construction efficiency of aluminum formwork.

[0072] (2) Comparing the data of Example 1 with Comparative Examples 1, 2 and 3 in the table, it can be seen that the concrete quality of the three commonly used formwork systems in engineering projects is in the order of best to worst as wooden formwork > steel formwork > aluminum formwork. This is because aluminum formwork has problems such as rapid heat dissipation, easy water accumulation on the concrete surface, and difficulty in removing air bubbles, resulting in lower concrete quality than steel formwork and wooden formwork. The data shows that the concrete quality under the aluminum formwork curing system of the present invention is also better than that of the steel formwork and wooden formwork curing systems used in engineering projects. This indicates that the aluminum formwork system of the present invention has basically overcome the concrete quality problems caused by the problems of aluminum formwork itself and ensures the quality requirements of concrete engineering.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A unidirectional thermal insulation water permeable membrane, characterized in that, The device comprises a hydrophilic layer, a thermal insulation layer, and a hydrophobic layer arranged sequentially. The hydrophilic layer is a nanoscale fiber membrane made by electrospinning a mixture of polyacrylamide, polyacrylamide, and cellulose acetate. The thermal insulation layer is a micron-scale green thermal insulation fiber membrane made by electrospinning a mixture of ultrafine alumina, ultrafine aluminum silicate, lignin fiber, reed fiber, and hemicellulose. The hydrophobic layer is a micron-scale fiber membrane made by electrospinning a mixture of polyacrylonitrile, polycarbonate, polycaprolactone, and poly(p-phenylene terephthalamide). In the hydrophilic layer, the mass ratio of polyacrylamide, polyacrylamide, and cellulose acetate is (2.5~3.3):(1.8~3.0):1.5; In the insulation layer, the mass ratio of ultrafine alumina, ultrafine aluminum silicate, lignin fiber, reed fiber, and hemicellulose is (1.6~2.4):(0.8~1.6):(3.1~3.8):(2.6~3.4):2; In the hydrophobic layer, the mass ratio of polyacrylonitrile, polycarbonate, polycaprolactone, and poly(p-phenylene terephthalamide) is 1:(1.7~2.5):(1.9:2.5):(2.1~2.8).

2. A method of producing a unidirectional thermal insulation water permeable membrane as claimed in claim 1, characterized in that, The method is as follows: Step 1: Prepare solvents for the hydrophilic layer, the insulating layer, and the hydrophobic layer respectively; Step 2: Dissolve the components of the hydrophilic layer, thermal insulation layer, and hydrophobic layer in their respective solvents to obtain the corresponding spinning solutions: Step 3: Prepare a hydrophilic layer, a thermal insulation layer, and a hydrophobic layer using a spinning solution to obtain a one-way thermal insulation and water-permeable membrane: Place the spinning solution corresponding to the hydrophilic layer into the syringe of an electrospinning device. Apply a high-voltage electrostatic field between the syringe and the receiving substrate. The applied high-voltage electrostatic field causes the spinning solution of the mixture to generate a jet under electrostatic action, resulting in a corresponding randomly arranged fiber membrane, i.e., the hydrophilic layer, on the receiving substrate. Prepare a micron-sized fiber membrane using the thermal insulation layer material and uniformly cover it on the surface of the receiving substrate composed of the nanoscale fiber membrane prepared from the hydrophilic layer material. Prepare a micron-sized fiber membrane using the hydrophobic layer material and uniformly cover it on the surface of the receiving substrate composed of the micron-sized membrane prepared from the thermal insulation layer material to form a one-way thermal insulation and water-permeable membrane.

3. The method of claim 2, wherein the unidirectional thermal insulation water permeable membrane is prepared by the steps of: The hydrophilic layer solvent is a mixture of deionized water, anhydrous ethanol, analytical grade ethylene glycol, and analytical grade acetone, with a mass ratio of 1.5:1:1:1; the insulation layer solvent is a mixture of deionized water, sodium lignosulfonate, sodium hydroxide, and pyridine, with a mass ratio of 2:1:0.5:1.5; the hydrophobic layer solvent is a mixture of dimethyl sulfoxide, carbon tetrachloride, and isopropyl acetate, with a mass ratio of 2:2:

1.

4. The method of claim 3, wherein the unidirectional thermal insulation water permeable membrane is prepared by the steps of: The hydrophilic layer mixture is dissolved in the corresponding solvent at room temperature (20-25°C) and stirred thoroughly until completely dissolved to obtain a spinning solution containing 10-40% of the mixture by mass. The thermal insulation layer material is dissolved in the corresponding solvent at room temperature (20-25°C) and stirred thoroughly until completely dissolved to obtain a spinning solution containing 15-45% of the thermal insulation layer material by mass. The hydrophobic layer mixture is dissolved in the corresponding solvent at room temperature (20-25°C) and stirred thoroughly until completely dissolved to obtain a spinning solution containing 10-35% of the mixture by mass.

5. A composite aluminum alloy formwork characterized by, It includes an aluminum alloy panel, an aluminum alloy back panel, and multiple end ribs; the aluminum alloy panel and the aluminum alloy back panel are arranged opposite each other and connected, and their edges are enclosed and fixed by multiple end ribs to form a template with an internal cavity; multiple drainage holes are provided on the aluminum alloy panel; the outer surface of the aluminum alloy panel is fully covered with a unidirectional heat-insulating and water-permeable membrane as described in claim 1, the unidirectional heat-insulating and water-permeable membrane includes a hydrophilic layer, a heat-insulating layer and a hydrophobic layer arranged in sequence, wherein the hydrophilic layer is attached to the outer surface of the aluminum alloy panel.

6. The composite aluminum alloy mold plate of claim 5, wherein, The end ribs are evenly distributed with threaded holes of the same size, which are straight through the rectangular grooves of the aluminum alloy panel and are fitted with bolts; the outer side of the aluminum alloy back plate is provided with two secondary ribs.

7. An aluminum alloy mold for curing concrete, characterized by comprising: The system includes five composite aluminum alloy templates as described in any one of claims 5 or 6. The five composite aluminum alloy templates are respectively set at the bottom and four sides, forming a pouring cavity with a top opening. Concrete is poured into the pouring cavity. The aluminum alloy panels of each composite aluminum alloy template face into the pouring cavity, and a release agent is evenly applied to the hydrophobic layer of the unidirectional heat-insulating and water-permeable membrane.

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