Geopolymer grouting material based on composite modified polyester fibers and processing method of geopolymer grouting material

Abstract

The invention discloses a geopolymer grouting material based on composite modified polyester fibers and a processing method of the geopolymer grouting material, and relates to the technical field of road engineering. The problems that in the prior art, polyester wig fiber resources are difficult to utilize, and a geopolymer grouting material is poor in crack resistance are effectively solved. According to the technical scheme, the geopolymer grouting material is prepared by mixing a component A and a component B, the component A comprises the following components in parts by mass: 70-80 parts of slag, 20-30 parts of fly ash, 0.8-1 part of a water reducing agent, 30-40 parts of water, 1-5 parts of fibers and 1-5 parts of a silane coupling agent; the component B is an alkali activator, the addition amount of the alkali activator is 50-60 parts by mass, the alkali activator takes industrial water glass with the modulus of 3.0-3.4 as a raw material, and the modulus of the water glass is adjusted to 1.2-2.0 by adding sodium hydroxide, potassium hydroxide or sodium carbonate. According to the reasonable and effective pretreatment method disclosed by the invention, resource utilization of the polyester wig fibers has great economic benefits and social benefits, and the problem of poor crack resistance of a geopolymer grouting material can be solved together.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, in particular to the field of road maintenance, and relates to a composite modification method of polyester wig fibers suitable for geopolymer grouting materials. Background Art

[0002] When cracks, dents, and voids appear in roads during long-term use, the service life of the road will be greatly shortened, causing direct economic losses to the maintenance department. In order to quickly and effectively solve road diseases, geopolymer grouting materials are usually used to repair roads. Benefiting from the unique physical and chemical properties of geopolymer grouting materials, geopolymer grouting materials have gradually attracted widespread attention in the field of road maintenance. However, most traditional grouting materials are brittle, prone to shrinkage after solidification, and have poor toughness.

[0003] At the same time, as a synthetic fiber, polyester fiber has many advantages, such as high breaking strength and elastic modulus, moderate resilience, excellent heat setting effect, and good heat and light resistance. Therefore, if the geopolymer grouting material and polyester fiber can be combined to improve the internal stress concentration phenomenon of the material and enhance the various properties of the grouting material after molding, it has become a technical problem that needs to be solved urgently by technicians in this field. Summary of the invention

[0004] In view of the above problems, the present invention proposes a composite modification method of polyester wig fibers for geopolymer grouting materials, which effectively solves the problems of difficult utilization of polyester wig fiber resources and poor crack resistance of geopolymer grouting materials in the prior art.

[0005] The technical solution of the present invention is: the geopolymer grouting material is prepared by mixing component A and component B;

[0006] Component A comprises the following ingredients by mass: 70-80 parts of slag, 20-30 parts of fly ash, 0.8-1 parts of water reducer, 30-40 parts of water, 1-5 parts of fiber, and 1-5 parts of silane coupling agent;

[0007] Component B is an alkali activator, which is added in an amount of 50 to 60 parts by mass. The alkali activator uses industrial water glass with a modulus of 3.0 to 3.4 as a raw material, and the modulus of the water glass is adjusted to 1.2 to 2.0 by adding sodium hydroxide, potassium hydroxide or sodium carbonate.

[0008] Furthermore, the fiber is activated polyester fiber, and the silane coupling agent is silane coupling agent KH550.

[0009] Furthermore, the raw material of the polyester fiber yarn is wig products.

[0010] Furthermore, the fly ash is of grade I or grade II.

[0011] The processing method is as follows: weigh the corresponding raw materials according to the proportion of component A and mix them evenly to form liquid A;

[0012] Adding solid sodium hydroxide or potassium hydroxide to water glass with a modulus of 3.0 to 3.4 to adjust the modulus of the water glass to 1.2 to 2.0, thereby obtaining a component B alkaline activator;

[0013] 50-60 parts of component B are added to component A and stirred for 5-10 minutes to obtain a geopolymer grouting material mixed with polyester fiber.

[0014] The fiber in component A is an activated polyester fiber, which is prepared according to the following steps:

[0015] First, the fiber filaments are cut to a length of 5 mm, and then the fiber filaments are extracted with acetone in a Soxhlet extractor for 2 hours. After the extraction, they are washed with pure water and dried in a drying oven at 80°C to constant weight. Then, they are soaked in a 5% sodium hydroxide solution and a 10% hydrochloric acid solution for 2 hours and washed respectively. Finally, they are extracted with acetone in a Soxhlet extractor for 2 hours. After washing with a large amount of pure water, they are placed in an oven at 80°C and dried to constant weight to obtain pretreated polyester fiber filaments.

[0016] The pretreated polyester fiber is placed under acidic conditions and oxidized in a strong oxidant. The process is as follows: 100 ml of pure water is used for every 3 g of fiber, and the fiber is stirred for 5 to 15 minutes. After stirring, 50 ml of sodium hypochlorite and concentrated hydrochloric acid in a ratio of 1:1 is poured in. After standing for 2 hours, the fiber is washed with pure water and then placed in an oven for drying to obtain the activated polyester fiber.

[0017] The present invention particularly takes into account that a large amount of waste fiber filaments will inevitably be generated during the production process of polyester wig fibers. The disposal of these waste fiber filaments by landfill or incineration will cause serious pollution to the environment. Therefore, finding a reasonable and effective pretreatment method to make resource utilization of polyester wig fibers has great economic and social benefits, and can also solve the problem of poor crack resistance of geopolymer grouting materials.

[0018] In the present invention, the addition of waste polyester chip product fiber filaments can form a spatial network distribution in the slurry, improve the internal stress concentration phenomenon of the material, and enhance the strength, crack resistance and stability of the grouting material after molding. In addition, the addition of the silane coupling agent can make the fiber and the slurry more firmly combined. After hydrolysis and condensation into oligomers, it has both inorganic-friendly hydroxyl groups and organic-friendly amino groups. The hydroxyl groups will dehydrate and condense with the hydroxyl groups on the surface of slag and fly ash to form hydrogen bonds and covalent bonds, and the amino groups can be tightly connected with the fiber, so that the fiber and the slurry can be more firmly combined. DETAILED DESCRIPTION

[0019] In order to clearly illustrate the technical features of this patent, this patent is elaborated in detail below through a specific implementation method.

[0020] The processing method of the present invention mainly includes: pretreatment and activation of fiber filaments and surface coupling modification during mixing of geopolymer grouting materials. The principle of composite modification is to pretreat and activate the fiber filaments first, and then add silane coupling agent solution during mixing of the geopolymer grouting materials to modify the fiber surface and strengthen the connection strength between the fiber and the grouting material, thereby forming a firm system.

[0021] Specifically:

[0022] The geopolymer grouting material is prepared by mixing component A and component B;

[0023] Component A contains the following ingredients by mass:

[0024] 70-80 parts of slag, 20-30 parts of fly ash, 0.8-1 parts of water reducer, 30-40 parts of water, 1-5 parts of fiber, 1-5 parts of silane coupling agent;

[0025] Component B is an alkali activator, which is added in an amount of 50 to 60 parts by mass. The alkali activator uses industrial water glass with a modulus of 3.0 to 3.4 as a raw material, and the modulus of the water glass is adjusted to 1.2 to 2.0 by adding sodium hydroxide, potassium hydroxide or sodium carbonate.

[0026] The fiber is activated polyester fiber filament, and the silane coupling agent is silane coupling agent KH550.

[0027] The fly ash shall be of Grade I or Grade II, with the total content of SiO2 and Al2O3 not less than 80% by mass; the particle size of slag shall not exceed 800 mesh, and the CaO content shall not be less than 30% by mass.

[0028] The preparation sequence of the geopolymer grouting material with polyester fiber added in the present invention is as follows:

[0029] Weigh the corresponding raw materials according to the proportion of component A above and mix them evenly to make liquid A;

[0030] Add a certain amount of sodium hydroxide or potassium hydroxide solid to commercially available water glass with a modulus of 3.0 to 3.4 to adjust the modulus of the water glass to 1.2 to 2.0, thereby obtaining a component B alkaline activator;

[0031] 50-60 parts of component B are added to component A and stirred for 5-10 minutes to obtain a geopolymer grouting material mixed with polyester fiber.

[0032] Among them, the pretreatment process of polyester fiber filaments is as follows: first, the fiber filaments are cut to a length of 5 mm, and then the fiber filaments are extracted with acetone in a Soxhlet extractor for 2 hours. After the extraction, they are washed with pure water, dried in a drying oven at 80°C to constant weight, and then soaked in 5% sodium hydroxide solution and 10% hydrochloric acid solution for 2 hours and washed separately, and finally extracted with acetone in a Soxhlet extractor for 2 hours. After washing with a large amount of pure water, they are placed in an oven at 80°C to dry to constant weight to obtain pretreated polyester fiber filaments.

[0033] The fiber activation process is as follows: the pretreated polyester fiber is placed under acidic conditions and oxidized in a strong oxidant. The process is to use 100 ml of pure water for every 3 g of fiber and stir for 5 to 15 minutes. After stirring, 50 ml of sodium hypochlorite and concentrated hydrochloric acid (ratio 1:1) are poured in, and after standing for 2 hours, the fiber is washed with pure water and then placed in an oven for drying to obtain the activated polyester fiber.

[0034] Advantages of activated fiber: The fiber surface is oxidatively modified by a strong oxidant, sodium hypochlorite solution. The strong oxidizing property of sodium hypochlorite is mainly used to oxidize double bonds, methylene and other groups on the fiber surface into oxygen-containing groups such as hydroxyl and carbonyl, thereby enhancing its surface activity.

[0035] What is special is that the polyester fiber yarn in this case is made of waste scraps from the production process, which is more economical and environmentally friendly.

[0036] The wig product is a fiber filament produced from polyester chips (PET) as raw materials, which is made by drying and dyeing the polyester chips, heating and melting, and cooling and stretching. It includes polyester fiber, high-temperature dye, auxiliary oil and flame retardant. The mass ratio of the polyester fiber, high-temperature dye, auxiliary oil and flame retardant is 70-85:5-10:5-10:5-10; the wig fiber has a length of 5 mm and a diameter of 2-9 μm after shearing.

[0037] In addition, the hydrolysis modification mechanism of silane coupling agent KH550 is as follows:

[0038] (1) Ethoxyl groups are hydrolyzed into silanols

[0039]

[0040] (2) Condensation of silanol into oligomers

[0041]

[0042] (3) Reaction connection between oligomers and inorganic materials

[0043]

[0044] By comparing the performance of geopolymer grouting materials added with general polyester fiber, geopolymer grouting materials added with activated polyester fiber, and geopolymer grouting materials added with activated and surface modified polyester fiber, the technical indicators are shown in the following table.

[0045] 1d compressive strength 1d flexural strength Adding general polyester fiber geopolymer grouting material 5.7 5.5 Geopolymer grouting material with activated polyester fiber 6.1 5.8 Geopolymer grouting material with activated and surface modified polyester fibers 6.9 6.0 Specification requirements ≥5MPa -

[0046] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A geopolymer grouting material based on composite modified polyester fiber, characterized in that: The geopolymer grouting material is prepared by mixing component A and component B; Component A comprises the following ingredients by mass: 70-80 parts of slag, 20-30 parts of fly ash, 0.8-1 parts of water reducer, 30-40 parts of water, 1-5 parts of fiber, and 1-5 parts of silane coupling agent; Component B is an alkali activator, which is added in an amount of 50 to 60 parts by mass. The alkali activator uses industrial water glass with a modulus of 3.0 to 3.4 as a raw material, and the modulus of the water glass is adjusted to 1.2 to 2.0 by adding sodium hydroxide, potassium hydroxide or sodium carbonate.

2. A geopolymer grouting material based on composite modified polyester fiber according to claim 1, characterized in that: The fiber is activated polyester fiber filament, and the silane coupling agent is silane coupling agent KH550.

3. A geopolymer grouting material based on composite modified polyester fiber according to claim 2, characterized in that: The raw material of the polyester fiber yarn is wig products.

4. The geopolymer grouting material based on composite modified polyester fiber according to claim 1, characterized in that: The fly ash is of grade I or grade II.

5. A method for processing the geopolymer grouting material according to claim 1, characterized in that: Weigh the corresponding raw materials according to the proportion of component A and mix them evenly to make liquid A; Adding solid sodium hydroxide or potassium hydroxide to water glass with a modulus of 3.0 to 3.4 to adjust the modulus of the water glass to 1.2 to 2.0, thereby obtaining a component B alkaline activator; 50-60 parts of component B are added to component A and stirred for 5-10 minutes to obtain a geopolymer grouting material mixed with polyester fiber.

6. A method for processing a geopolymer grouting material according to claim 5, characterized in that: The fiber in component A is an activated polyester fiber, which is prepared according to the following steps: First, the fiber filaments are cut to a length of 5 mm, and then the fiber filaments are extracted with acetone in a Soxhlet extractor for 2 hours. After the extraction, they are washed with pure water and dried in a drying oven at 80°C to constant weight. Then, they are soaked in a 5% sodium hydroxide solution and a 10% hydrochloric acid solution for 2 hours and washed respectively. Finally, they are extracted with acetone in a Soxhlet extractor for 2 hours. After washing with a large amount of pure water, they are placed in an oven at 80°C and dried to constant weight to obtain pretreated polyester fiber filaments. The pretreated polyester fiber is placed under acidic conditions and oxidized in a strong oxidant. The process is as follows: 100 ml of pure water is used for every 3 g of fiber, and the fiber is stirred for 5 to 15 minutes. After stirring, 50 ml of sodium hypochlorite and concentrated hydrochloric acid in a ratio of 1:1 is poured in. After standing for 2 hours, the fiber is washed with pure water and then placed in an oven for drying to obtain the activated polyester fiber.

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