Modified fiber for cement-based material

Abstract

The invention relates to the technical field of building materials, in particular to a modified fiber for a cement-based material. Comprising the following components in percentage by mass: 15-20% of acetone, 15-18% of ultra-high molecular weight polyethylene fibers, 12-15% of ethanol, 9-12% of concentrated nitric acid, 8-10% of a gamma-aminopropyltriethoxysilane ethanol solution, 6-9% of modified nano silicon dioxide, 3-5% of a sodium hydroxide solution and the balance of water. The modified fiber for the cement-based material, provided by the invention, has the beneficial effects that the surface of the ultra-high molecular weight polyethylene fiber is treated by adopting a method for oxidizing the ultra-high molecular weight polyethylene fiber through nitric acid, so that a cement matrix and the ultra-high molecular weight polyethylene fiber are bonded more tightly; therefore, the compressive strength of the ultra-high molecular weight polyethylene fiber cement-based material is effectively improved; the problem that an existing cement-based material cracks due to low compressive strength and flexural strength is further solved, and the compressive strength and flexural strength of the cement-based material can be improved by adding the modified fibers.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to a modified fiber used for cement-based materials. Background Art

[0002] Cement-based composite materials refer to composite materials with silicate cement as the matrix, alkali-resistant glass fiber, general synthetic fiber, various ceramic fibers, high-performance fibers such as carbon and aramid, metal wire, natural plant fiber and mineral fiber as reinforcement, and fillers, chemical additives and water added through a composite process.

[0003] In the existing technology, cement-based materials are the indispensable and most important construction materials in the world's civil engineering field. However, their relatively low compressive and flexural strengths make it inevitable for them to crack under the influence of internal and external factors. Cracks affect the integrity and functionality of the building structure, provide a convenient channel for corrosive media to enter the interior of the concrete, and cause varying degrees of erosion and damage to the engineering structure, resulting in a continuous decrease in concrete performance, seriously affecting the durability and service life of the project.

[0004] Therefore, we need a modified fiber for cement-based materials to solve the crack problem caused by low compressive and flexural strength of existing cement-based materials. The compressive and flexural strength of cement-based materials can be improved by adding modified fibers. Summary of the invention

[0005] The purpose of the present invention is to provide a modified fiber for cement-based materials to solve the crack problem caused by low compressive and flexural strength of existing cement-based materials mentioned in the above background technology. The compressive and flexural strength of cement-based materials can be improved by adding modified fibers.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a modified fiber for cement-based materials, wherein the modified fiber comprises the following components by mass fraction: 15-20% acetone, 15-18% ultra-high molecular weight polyethylene fiber, 12-15% ethanol, 9-12% concentrated nitric acid, 8-10% γ-aminopropyltriethoxysilane ethanol solution, 6-9% modified nano-silicon dioxide, 3-5% sodium hydroxide solution, and the rest is water.

[0007] Preferably, the modified fiber comprises the following components by mass fraction: 15% acetone, 15% ultra-high molecular weight polyethylene fiber, 12% ethanol, 9% concentrated nitric acid, 8% γ-aminopropyltriethoxysilane ethanol solution, 6% modified nano-silica, 3% sodium hydroxide solution, and the rest is water.

[0008] Preferably, the modified fiber comprises the following components by mass fraction: 17% acetone, 16% ultra-high molecular weight polyethylene fiber, 13% ethanol, 10% concentrated nitric acid, 9% γ-aminopropyltriethoxysilane ethanol solution, 7% modified nano-silicon dioxide, 4% sodium hydroxide solution, and the rest is water.

[0009] Preferably, the modified fiber comprises the following components by mass fraction: 19% acetone, 17% ultra-high molecular weight polyethylene fiber, 14% ethanol, 11% concentrated nitric acid, 9% γ-aminopropyltriethoxysilane ethanol solution, 8% modified nano-silicon dioxide, 4% sodium hydroxide solution, and the rest is water.

[0010] Preferably, the modified fiber comprises the following components by mass fraction: 20% acetone, 18% ultra-high molecular weight polyethylene fiber, 15% ethanol, 12% concentrated nitric acid, 10% γ-aminopropyltriethoxysilane ethanol solution, 9% modified nano-silica, 5% sodium hydroxide solution, and the rest is water.

[0011] Preferably, the substitute for acetone is any one of ethyl acetate, isopropanol and acetonitrile.

[0012] Preferably, the substitute for the ultra-high molecular weight polyethylene fiber is at least one of ultra-high molecular weight polyethylene and polyvinyl alcohol fiber.

[0013] An application of modified fibers for cement-based materials, and an application of the modified fibers for cement-based materials in the production of building materials.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The modified fiber for cement-based materials proposed in the present invention adopts a method for treating ultra-high molecular weight polyethylene fibers by nitric acid oxidation to treat the surface of the ultra-high molecular weight polyethylene fibers, so that the cement matrix and the ultra-high molecular weight polyethylene fibers are more tightly bonded, thereby effectively improving the compressive strength of the ultra-high molecular weight polyethylene fiber cement-based materials; further solving the problem of cracks caused by low compressive and flexural strength of existing cement-based materials, and the compressive and flexural strength of the cement-based can be improved by adding modified fibers. DETAILED DESCRIPTION

[0016] In order to make the purpose and technical solution of the present invention clearly and completely described, and the advantages more clearly understood. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Embodiment 1

[0018] The present invention provides a technical solution: a modified fiber for cement-based materials, the modified fiber comprising the following components by mass fraction: 15% acetone, 15% ultra-high molecular weight polyethylene fiber, 12% ethanol, 9% concentrated nitric acid, 8% γ-aminopropyl triethoxysilane ethanol solution, 6% modified nano silicon dioxide, 3% sodium hydroxide solution, and the rest being water;

[0019] The acetone and sodium hydroxide solution are sequentially added to the ultra-high molecular weight polyethylene fiber, refluxed at 75°C for 10 hours, filtered, repeatedly washed with ethanol and water, dried, immersed in concentrated nitric acid, heated to 50°C, reacted for 2 hours, repeatedly washed with ethanol and water, dried, immersed in γ-aminopropyltriethoxysilane ethanol solution, heated to 70°C, reacted for 3 hours, ethanol extracted for 24 hours, dried, immersed in modified nano-silica, ultrasonically reacted for 2 hours, washed with ethanol, and repeated 6 times to obtain modified ultra-high molecular weight polyethylene fiber;

[0020] Mortar specimens were prepared with cement, sand, modified ultra-high molecular weight polyethylene fiber and water, and a calcium source was added. The specimens were first cured at 25°C for 25 hours, and then cured in a 25°C water environment for 7 to 28 days. The 28-day flexural strength and 28-day compressive strength were tested according to GB / T17671-1999 "Test method for strength of cement mortar".

[0021] Embodiment 2

[0022] A modified fiber for cement-based materials, the modified fiber comprising the following components by mass fraction: 17% acetone, 16% ultra-high molecular weight polyethylene fiber, 13% ethanol, 10% concentrated nitric acid, 9% γ-aminopropyltriethoxysilane ethanol solution, 7% modified nano silicon dioxide, 4% sodium hydroxide solution, and the rest being water;

[0023] The acetone and sodium hydroxide solution are sequentially added to the ultra-high molecular weight polyethylene fiber, refluxed at 60°C for 10 hours, filtered, repeatedly washed with ethanol and water, dried, immersed in concentrated nitric acid, heated to 50°C, reacted for 2 hours, repeatedly washed with ethanol and water, dried, immersed in γ-aminopropyltriethoxysilane ethanol solution, heated to 70°C, reacted for 3 hours, ethanol extracted for 24 hours, dried, immersed in modified nano-silica, ultrasonically reacted for 2 hours, washed with ethanol, and repeated 6 times to obtain modified ultra-high molecular weight polyethylene fiber;

[0024] Mortar specimens were prepared with cement, sand, modified ultra-high molecular weight polyethylene fiber and water, and a calcium source was added. The specimens were first cured at 25°C for 24 hours, and then cured in a 25°C water environment for 7 to 28 days. The 28-day flexural strength and 28-day compressive strength were tested according to GB / T17671-1999 "Test method for strength of cement mortar".

[0025] Embodiment 3

[0026] A modified fiber for cement-based materials, the modified fiber comprising the following components by mass fraction: 19% acetone, 17% ultra-high molecular weight polyethylene fiber, 14% ethanol, 11% concentrated nitric acid, 9% γ-aminopropyltriethoxysilane ethanol solution, 8% modified nano silicon dioxide, 4% sodium hydroxide solution, and the rest being water;

[0027] The acetone and sodium hydroxide solution are sequentially added to the ultra-high molecular weight polyethylene fiber, refluxed at 65°C for 10 hours, filtered, repeatedly washed with ethanol and water, dried, immersed in concentrated nitric acid, heated to 50°C, reacted for 2 hours, repeatedly washed with ethanol and water, dried, immersed in γ-aminopropyltriethoxysilane ethanol solution, heated to 70°C, reacted for 3 hours, ethanol extracted for 24 hours, dried, immersed in modified nano-silica, ultrasonically reacted for 2 hours, washed with ethanol, and repeated 6 times to obtain modified ultra-high molecular weight polyethylene fiber;

[0028] Mortar specimens were prepared with cement, sand, modified ultra-high molecular weight polyethylene fiber and water, and a calcium source was added. The specimens were first cured at 25°C for 25 hours, and then cured in a 25°C water environment for 7 to 28 days. The 28-day flexural strength and 28-day compressive strength were tested according to GB / T17671-1999 "Test method for strength of cement mortar".

[0029] Embodiment 4

[0030] A modified fiber for cement-based materials, the modified fiber comprising the following components by mass fraction: 20% acetone, 18% ultra-high molecular weight polyethylene fiber, 15% ethanol, 12% concentrated nitric acid, 10% γ-aminopropyltriethoxysilane ethanol solution, 9% modified nano silicon dioxide, 5% sodium hydroxide solution, and the rest being water;

[0031] The acetone and sodium hydroxide solution are sequentially added to the ultra-high molecular weight polyethylene fiber, refluxed at 80°C for 10 hours, filtered, repeatedly washed with ethanol and water, dried, immersed in concentrated nitric acid, heated to 50°C, reacted for 2 hours, repeatedly washed with ethanol and water, dried, immersed in γ-aminopropyltriethoxysilane ethanol solution, heated to 70°C, reacted for 3 hours, ethanol extracted for 24 hours, dried, immersed in modified nano-silica, ultrasonically reacted for 2 hours, washed with ethanol, and repeated 6 times to obtain modified ultra-high molecular weight polyethylene fiber;

[0032] Mortar specimens were prepared with cement, sand, modified ultra-high molecular weight polyethylene fiber and water, and a calcium source was added. The specimens were first cured at 25°C for 26 hours, and then cured in a 25°C water environment for 7 to 28 days. The 28-day flexural strength and 28-day compressive strength were tested according to GB / T17671-1999 "Test method for strength of cement mortar".

[0033] The performance parameters of the fiber-modified cement-based reinforcement materials prepared in Examples 1 to 4 are shown in Table 1.

[0034] Table 1 Performance parameters of fiber-modified cement-based reinforcement materials

[0035]

[0036] The fiber-modified cement-based reinforced materials prepared according to Examples 1 to 4 have flexural resistance, compressive strength and wear resistance. The method has good repair effect, low cost, simple process and convenient operation, which helps to improve the durability and service life of the project.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A modified fiber for cement-based materials, characterized in that: The modified fiber comprises the following components by mass fraction: 15-20% acetone, 15-18% ultra-high molecular weight polyethylene fiber, 12-15% ethanol, 9-12% concentrated nitric acid, 8-10% gamma-aminopropyl triethoxysilane ethanol solution, 6-9% modified nano silicon dioxide, 3-5% sodium hydroxide solution, and the rest is water.

2. The modified fiber for cement-based materials according to claim 1, characterized in that: The modified fiber comprises the following components by mass fraction: 15% acetone, 15% ultra-high molecular weight polyethylene fiber, 12% ethanol, 9% concentrated nitric acid, 8% gamma-aminopropyl triethoxysilane ethanol solution, 6% modified nano silicon dioxide, 3% sodium hydroxide solution, and the rest is water.

3. The modified fiber for cement-based materials according to claim 1, characterized in that: The modified fiber comprises the following components by mass fraction: 17% acetone, 16% ultra-high molecular weight polyethylene fiber, 13% ethanol, 10% concentrated nitric acid, 9% gamma-aminopropyl triethoxysilane ethanol solution, 7% modified nano silicon dioxide, 4% sodium hydroxide solution, and the rest is water.

4. The modified fiber for cement-based materials according to claim 1, characterized in that: The modified fiber comprises the following components by mass fraction: 19% acetone, 17% ultra-high molecular weight polyethylene fiber, 14% ethanol, 11% concentrated nitric acid, 9% gamma-aminopropyl triethoxysilane ethanol solution, 8% modified nano silicon dioxide, 4% sodium hydroxide solution, and the rest is water.

5. The modified fiber for cement-based materials according to claim 1, characterized in that: The modified fiber comprises the following components by mass fraction: 20% acetone, 18% ultra-high molecular weight polyethylene fiber, 15% ethanol, 12% concentrated nitric acid, 10% gamma-aminopropyl triethoxysilane ethanol solution, 9% modified nano silicon dioxide, 5% sodium hydroxide solution, and the rest is water.

6. The modified fiber for cement-based materials according to claim 1, characterized in that: The substitute of acetone is any one of ethyl acetate, isopropanol and acetonitrile.

7. The modified fiber for cement-based materials according to claim 1, characterized in that: The substitute for the ultra-high molecular weight polyethylene fiber is selected from at least one of ultra-high molecular weight polyethylene and polyvinyl alcohol fibers.

8. An application of the modified fiber for cement-based materials according to any one of claims 1 to 7, characterized in that: The modified fiber for cement-based materials is used in the production of building materials.

Images