High-strength resin concrete with compactness enhanced through magnetic attraction and preparation method of high-strength resin concrete

Abstract

The invention provides high-strength resin concrete with compactness enhanced through magnetic attraction and a preparation method of the high-strength resin concrete, and belongs to the technical field of concrete. The high-strength resin concrete with the compactness enhanced through magnetic attraction is prepared from the following raw materials in parts by weight: 77 to 81 parts of common basalt stones, 8.5 to 10.5 parts of magnetic Fe2O3-loaded small-particle-size basalt stones, 8 to 9.6 parts of epoxy resin, 2 to 2.4 parts of a curing agent and 0.5 part of Fe3O4-SiO2. According to the high-strength resin concrete with the compactness enhanced through magnetic attraction, based on the continuous grading theory, the prepared epoxy resin concrete has the advantages of being large in stacking density, low in porosity, high in strength and high in abrasion resistance through a nanoparticle coating and loading technology, and the compactness is enhanced through magnetic introduction; damage detection of the internal structure of the material is simpler and more convenient, nondestructive detection of the material can be completed, and the method has a great application prospect.

Description

[0001] This invention relates to a high-strength resin concrete with enhanced density due to magnetic attraction and its preparation method, belonging to the field of concrete technology. Background Technology

[0002] Resin concrete, also known as polymer-bonded concrete, is a special type of concrete made by using synthetic resins (polymers) or monomers as cementing materials and appropriate curing agents, toughening agents, and other additives, combined with sand and gravel aggregates. Research on polymer concrete began in the United States in the 1950s, primarily as a repair material, and in recent years it has begun to be applied to road paving and other engineering projects. Domestic technology development in this area started later, and research has mainly focused on mix design. A reasonable mix design is fundamental and crucial for ensuring concrete performance, and it has also been a relatively difficult area for improving concrete technology over the years.

[0003] With research advancements, the number of admixtures and additives used in polymer concrete has gradually increased. Based on economic and practical considerations, mix design methods relying on the theory of close packing have developed rapidly, mainly including two categories: continuous gradation theory and discontinuous gradation theory. Polymer concrete prepared using the continuous gradation theory has a relatively uniform aggregate gradation distribution, but its density is relatively low. Polymer concrete prepared using the discontinuous gradation theory eliminates some graded aggregates, increasing the bulk density of the concrete. However, its discontinuous gradation method easily leads to bleeding and segregation phenomena in the concrete, affecting its performance.

[0004] To address the current problems with polymer concrete, improving its density while ensuring uniform aggregate distribution and reducing bleeding and segregation are crucial goals for enhancing its overall performance. Basalt, a commonly used aggregate in polymer concrete, is primarily composed of silicon dioxide. Due to the gradation requirements of polymer concrete, basalt particles have a wide particle size distribution. To increase density while maintaining uniform aggregate gradation, the primary consideration is the packing density of small-diameter aggregates. Enhancing the packing density of small-diameter aggregates is a key breakthrough in solving this problem. Summary of the Invention

[0005] This invention addresses the aforementioned problems by providing a high-strength resin concrete with enhanced density through magnetic attraction and its preparation method. This invention utilizes an active magnetic adsorption material combined with a highly stable SiO2 film, enabling the firm packing of small-diameter aggregates while ensuring uniform aggregate gradation in the polymer concrete. This achieves self-filling of the polymer concrete, effectively increasing its bulk density and resulting in higher strength, greater durability, and a longer service life. It achieves a significant improvement in density and performance compared to ordinary polymer concrete, laying a solid foundation for its wider practical applications.

[0006] The active magnetic adsorption material used in this invention is Fe3O4 nanoparticles, which are externally modified and coated with active SiO2 using a sol-gel method, effectively improving their physicochemical properties and enhancing the material's stability. This invention also employs high-flowability epoxy resin as a binder for polymer concrete, which possesses excellent physicochemical properties, is safe and environmentally friendly, and will not cause pollution, aligning with the concept of sustainable development.

[0007] This invention uses basalt stones as aggregate in polymer concrete and performs surface modification treatment on the small-diameter aggregates. A simple sol-gel method is used to effectively load magnetic Fe2O3 particles onto the surface of the small-diameter aggregates. During the preparation of the polymer concrete, SiO2-coated active Fe3O4 magnetic adsorbent is added to epoxy resin slurry and stirred evenly. A curing agent is added, and then the basalt-graded aggregate containing magnetic Fe2O3-loaded small-diameter stones is poured in and stirred. During stirring, due to the presence of magnetic materials in the resin slurry and small-diameter stones, a significant attraction is generated. The mutual attraction between the resin and the small-diameter stones effectively seals the small gaps in the polymer concrete, resulting in a tighter bond between the resin and the stones. This significantly improves the packing density of the resin concrete, enhances its strength and wear resistance, and effectively resolves the contradiction between two different gradation theories.

[0008] The technical solution of the high-strength resin concrete with enhanced density through magnetic attraction described in this invention is as follows:

[0009] A high-strength resin concrete with enhanced density through magnetic attraction is prepared from the following raw materials in parts by weight: 77-81 parts of ordinary basalt gravel, 8.5-10.5 parts of small-particle basalt gravel loaded with magnetic Fe2O3, 8-9.6 parts of epoxy resin, 2-2.4 parts of curing agent, and 0.5 parts of Fe3O4@SiO2.

[0010] The Fe3O4@SiO2 is prepared from the following raw materials in parts by weight: 30 parts Fe3O4 nanoparticles, 55 parts ethanol, 10 parts tetraethyl silicate, and 5 parts ammonia.

[0011] The small-particle-size basalt pebbles loaded with magnetic Fe2O3 are prepared from the following raw materials in parts by weight: 45-48 parts small-particle-size basalt pebbles, 45-48 parts anhydrous ethanol, 1 part polyvinylpyrrolidone, and 6 parts magnetic Fe2O3. Preferably, the polyvinylpyrrolidone is K30.

[0012] Preferably, the epoxy resin used is a high-flow epoxy resin with an initial viscosity of 30 MPa / s;

[0013] Preferably, the magnetic Fe2O3 uses magnetic Fe2O3 ultrafine powder (γ-Fe2O3 ultrafine powder) with a particle size of 20-200 nm;

[0014] Preferably, the high-strength resin concrete is prepared from the following raw materials in parts by weight: 79.5 parts of ordinary basalt gravel, 10 parts of small-particle basalt gravel loaded with magnetic Fe2O3, 8 parts of epoxy resin, 2 parts of curing agent, and 0.5 parts of Fe3O4@SiO2.

[0015] Further preferred, ordinary basalt gravel uses a gradation of 0.6–9.5 mm;

[0016] Further preferred, small-diameter basalt stones are used in the range of 0.075–0.3 mm.

[0017] The preparation method of high-strength resin concrete with enhanced density through magnetic attraction involves the following steps:

[0018] 1. Take a certain amount of Fe3O4 nanoparticles, add an appropriate amount of ethanol (volume fraction 80%), then add tetraethyl silicate and ammonia water dropwise, stir at room temperature for 6 hours, wash and dry with deionized water to obtain SiO2-coated Fe3O4 nanoparticles (Fe3O4@SiO2).

[0019] 2. A certain amount of polyvinylpyrrolidone was added to anhydrous ethanol solution and stirred evenly. Then magnetic Fe2O3 was added. Subsequently, it was placed in a reaction vessel with small-particle-size basalt stones and heated at 40°C for 2 hours. After drying at room temperature, small-particle-size basalt stones loaded with magnetic Fe2O3 were obtained.

[0020] 3. Add the Fe3O4@SiO2 prepared in step 1 to the epoxy resin and stir until homogeneous. Then add the curing agent and stir until homogeneous. This mixture is then added to the aggregate of small-particle-size basalt stones supported by magnetic Fe2O3 prepared in step 2, combined with ordinary basalt stone aggregate. The mixture is then poured to obtain high-strength resin concrete with enhanced density due to magnetic attraction. The technical principle of the preparation method of high-strength resin concrete with enhanced density due to magnetic attraction described in this invention is as follows:

[0021] (1) Based on the continuous gradation theory of polymer concrete, the attractive force of Fe3O4 and magnetic Fe2O3 is used to improve the internal density of concrete, increase the packing density of materials, and enhance the strength and wear resistance of polymer concrete.

[0022] (2) Fe3O4 nanoparticles were coated with SiO2 using the Stober method to obtain Fe3O4@SiO2. The SiO2 provides a stable outer shell, protecting Fe3O4 from external environmental influences and preventing its properties from changing and losing magnetism during polymer concrete preparation. This also improves the dispersibility of Fe3O4 in epoxy resin; uniformly dispersed Fe3O4@SiO2 is more conducive to improving the internal density of polymer concrete during preparation.

[0023] (3) A simple sol-gel method was used to uniformly load magnetic Fe2O3 onto the surface of small-diameter basalt particles. The reason for selecting small-diameter basalt particles for loading is that the particle size range of small-diameter basalt particles is between 0.075 and 0.3 mm. They are small in size and have a lighter weight, which can effectively exert the attraction between Fe3O4@SiO2 and magnetic Fe2O3, thereby improving the density of continuously graded polymer concrete.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The high-strength resin concrete with enhanced density prepared by the present invention utilizes the mutual attraction between Fe3O4@SiO2 and magnetic Fe2O3 to improve the bonding force between epoxy resin and basalt particles, effectively densify the internal structure of polymer concrete, and improve the strength and durability of polymer concrete.

[0026] (2) This invention improves upon the continuous gradation theory of polymer concrete. The polymer concrete prepared using the continuous gradation theory has a relatively uniform aggregate distribution, which can ensure the non-bleeding and segregation properties of polymer concrete. Then, only small-diameter basalt particles are selected for modification, which effectively ensures the magnetic attraction effect while using less resources to achieve the effect of discontinuous gradation theory, and significantly improves the packing density of polymer concrete.

[0027] (3) The high-strength resin concrete with enhanced density due to magnetic attraction prepared by this invention has good damage detection capabilities due to the presence of internal magnetic materials, enabling non-destructive testing. Furthermore, it possesses a certain magnetic adsorption function, capable of adsorbing magnetic pollutants and purifying the surrounding environment, thus demonstrating broad application prospects. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments. The advantages and features of the present invention will become clearer with further description. However, the embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0029] Example 1:

[0030] (1) Take 30g of Fe3O4 nanoparticles and place them in 55g of ethanol (volume fraction 80%), then add 10g of tetraethyl silicate and 5g of ammonia water, stir at room temperature for 6h, wash and dry with deionized water to obtain SiO2-coated Fe3O4 nanoparticles (Fe3O4@SiO2).

[0031] (2) Take 2g of polyvinylpyrrolidone, add it to 90g of anhydrous ethanol solution and stir evenly. Then add 12g of magnetic Fe2O3, and then place it and 96g of small-diameter basalt stones in a reaction vessel and heat at 40℃ for 2h. Then dry at room temperature to obtain small-diameter basalt stones loaded with magnetic Fe2O3.

[0032] (3) Take 5g of Fe3O4@SiO2 prepared in step (1) and add it to 80g of epoxy resin and stir evenly. Then add 20g of curing agent and stir evenly.

[0033] (4) Take 85g of magnetic Fe2O3-loaded small-particle-size basalt stones prepared in step (2), and mix them with 810g of ordinary basalt stone graded aggregate and the product obtained in step (3). After mixing evenly, pour the mixture to obtain high-strength resin concrete with enhanced density due to magnetic attraction.

[0034] Example 2:

[0035] (1) Take 30g of Fe3O4 nanoparticles and place them in 55g of ethanol (volume fraction 80%), then add 10g of tetraethyl silicate and 5g of ammonia water, stir at room temperature for 6h, wash and dry with deionized water to obtain SiO2-coated Fe3O4 nanoparticles (Fe3O4@SiO2).

[0036] (2) Take 2g of polyvinylpyrrolidone, add it to 90g of anhydrous ethanol solution and stir evenly. Then add 12g of magnetic Fe2O3, and then place it and 96g of small-diameter basalt stones in a reaction vessel and heat at 40℃ for 2h. Then dry at room temperature to obtain small-diameter basalt stones loaded with magnetic Fe2O3.

[0037] (3) Take 5g of Fe3O4@SiO2 prepared in step (1) and add it to 80g of epoxy resin and stir evenly. Then add 20g of curing agent and stir evenly.

[0038] (4) Take 105g of magnetic Fe2O3-loaded small-particle-size basalt stones prepared in step (2), combine them with 790g of ordinary basalt stone graded aggregate and the product obtained in step (3), mix and stir, and pour the mixture after it is evenly mixed to obtain high-strength resin concrete with enhanced density due to magnetic attraction.

[0039] Example 3:

[0040] (1) Take 30g of Fe3O4 nanoparticles and place them in 55g of ethanol (volume fraction 80%), then add 10g of tetraethyl silicate and 5g of ammonia water, stir at room temperature for 6h, wash and dry with deionized water to obtain SiO2-coated Fe3O4 nanoparticles (Fe3O4@SiO2).

[0041] (2) Take 2g of polyvinylpyrrolidone, add it to 90g of anhydrous ethanol solution and stir evenly. Then add 12g of magnetic Fe2O3, and then place it and 96g of small-diameter basalt stones in a reaction vessel and heat at 40℃ for 2h. Then dry at room temperature to obtain small-diameter basalt stones loaded with magnetic Fe2O3.

[0042] (3) Take 5g of Fe3O4@SiO2 prepared in step (1) and add it to 96g of epoxy resin and stir evenly. Then add 24g of curing agent and stir evenly.

[0043] (4) Take 105g of magnetic Fe2O3-loaded small-particle-size basalt stones prepared in step (2), combine them with 770g of ordinary basalt stone graded aggregate and the product obtained in step (3), mix and stir, and pour the mixture after it is evenly mixed to obtain high-strength resin concrete with enhanced density due to magnetic attraction.

[0044] Products prepared in different embodiments were poured into 100mm×100mm×100mm concrete molds, and the strength of the specimens was tested according to GB / T50081-2010 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" to obtain the following data:

[0045] type 28-day compressive strength 28d flexural strength Material density Example 1 162.3MPa 29.8MPa <![CDATA[2.34g / cm 3 ]]> Example 2 186.7 MPa 33.5MPa <![CDATA[2.48g / cm 3 ]]> Example 3 173.8 MPa 30.6MPa <![CDATA[2.43g / cm 3 ]]>

Claims

1. A high-strength resin concrete with enhanced density through magnetic attraction, characterized in that: By weight, it is composed of the following raw materials: 77-81 parts of ordinary basalt pebble, 8.5-10.5 parts of small-particle basalt pebble loaded with magnetic Fe2O3, 8-9.6 parts of epoxy resin, 2-2.4 parts of curing agent, and 0.5 parts of Fe3O4@SiO2. The Fe3O4@SiO2 is prepared from the following raw materials: 30 parts Fe3O4 nanoparticles, 55 parts ethanol, 10 parts tetraethyl silicate, and 5 parts ammonia. The small-particle-size basalt pebble loaded with magnetic Fe2O3 is prepared from the following raw materials: 45-48 parts of small-particle-size basalt pebble, 45-48 parts of anhydrous ethanol, 1 part of polyvinylpyrrolidone, and 6 parts of magnetic Fe2O3.

2. The high-strength resin concrete with enhanced density through magnetic attraction according to claim 1, characterized in that: The particle size range of the ordinary basalt stones is 0.6 to 9.5 mm, and the particle size range of the small-diameter basalt stones is 0.075 to 0.3 mm.

3. The high-strength resin concrete with enhanced density through magnetic attraction according to claim 1, characterized in that: The epoxy resin is a high-flow epoxy resin with an initial viscosity of 30 MPa / s.

4. The high-strength resin concrete with enhanced density through magnetic attraction according to claim 1, characterized in that: The polyvinylpyrrolidone is of model number K30.

5. The high-strength resin concrete with enhanced density through magnetic attraction according to claim 1, characterized in that: The magnetic Fe2O3 is ultrafine magnetic iron oxide γ-Fe2O3 with a particle size of 20-200 nm.

6. A method for preparing high-strength resin concrete with enhanced density through magnetic attraction according to any one of claims 1-5, characterized in that, Includes the following steps: Fe3O4@SiO2 was added to epoxy resin and stirred, followed by the addition of curing agent and stirring. This mixture was then combined with ordinary basalt gravel and small-particle basalt gravel loaded with magnetic Fe2O3, stirred, and poured to obtain high-strength resin concrete with enhanced density due to magnetic attraction.

7. The method for preparing high-strength resin concrete with enhanced density through magnetic attraction according to claim 6, characterized in that, The preparation method of Fe3O4@SiO2 is as follows: Take 30g of Fe3O4 nanoparticles, add 55g of ethanol, then add 10g of tetraethyl silicate and 5g of ammonia water, stir at room temperature for 6h, wash with deionized water, and dry to obtain SiO2-coated Fe3O4 nanoparticles, namely Fe3O4@SiO2.

8. The method for preparing high-strength resin concrete with enhanced density through magnetic attraction according to claim 6, characterized in that, The method for preparing the small-particle-size basalt stones loaded with magnetic Fe2O3 is as follows: 2g of polyvinylpyrrolidone was added to 90g of anhydrous ethanol solution and stirred. Then, 12g of magnetic Fe2O3 and 96g of small-diameter basalt stones were added. After mixing, the mixture was placed in a reaction vessel and heated at 40℃ for 2h. The mixture was then dried at room temperature to obtain small-diameter basalt stones supported by magnetic Fe2O3.