Preparation process of volcanic rock active admixture and concrete material thereof

Abstract

The present invention discloses a volcanic rock active admixture and a process for preparing the same for concrete materials. The process for preparing the admixture comprises: (1) mixing volcanic rock particles, nano-silica, a silane coupling agent, and triethanolamine, and then mechanically grinding the mixture under heating conditions to obtain pretreated volcanic rock powder. (2) mixing the pretreated volcanic rock powder with a calcium source, sodium silicate, polyethylene glycol, and water, and then allowing the mixture to stand, then heating and continuously stirring the mixture to maintain the temperature, separating the solid product, and drying the mixture to obtain the volcanic rock admixture. The volcanic rock admixture treated by the above process of the present invention has excellent hydration reaction activity and can effectively improve the mechanical properties of concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete material preparation, and in particular to a volcanic rock active admixture and a preparation process of the concrete material thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Concrete is a building material made by mixing cement as a binder, sand and stone as aggregates, and other mineral admixtures, additives, and water in specific proportions. Mineral admixtures are a key component of modern concrete. They are primarily made by grinding industrial waste slag from steel, chemical, and power plants, and include fly ash, granulated blast furnace slag powder, silica fume, phosphorus slag powder, zeolite powder, and others. The aluminosilicate glass in mineral admixtures can participate in the hydration reaction of cement in concrete, thereby improving the workability, mechanical properties, and durability of concrete. However, with the development of clean energy and improvements in steelmaking processes, high-quality mineral admixtures have become increasingly scarce and are unable to meet the production needs of concrete. Therefore, there is an urgent need for alternative materials to mineral admixtures and their preparation technologies.

[0004] Volcanic rock is a densely porous, glassy lava formed during volcanic eruptions. It is widely distributed in my country, and its primary chemical composition is aluminosilicate, similar to that of aluminosilicate mineral admixtures, making it a promising mineral admixture. However, the reactivity of volcanic rock is far lower than that of aluminosilicate mineral admixtures. This is primarily due to its intact aluminum-silicon bond crystal structure and high degree of polymerization, resulting in lower reactivity. When added to concrete, its contribution to the mechanical properties of concrete is minimal, and excessive additions can even lead to a decrease in the mechanical properties of concrete. This makes it difficult for volcanic rock to truly replace these mineral admixtures and alleviate the growing shortage of high-quality mineral admixtures. Summary of the Invention

[0005] To address the above-mentioned issues, the present invention provides a process for preparing a volcanic rock active admixture and its concrete material. The volcanic rock admixture treated by this process exhibits excellent hydration reaction activity, effectively improving the mechanical properties of concrete. Specifically, the technical solution of the present invention is as follows.

[0006] First, the present invention provides a preparation process of a volcanic rock admixture, comprising the following steps:

[0007] (1) Volcanic rock particles, nano-silica, silane coupling agent and triethanolamine are mixed and mechanically ground under heating conditions to obtain pretreated volcanic rock powder.

[0008] (2) The pretreated volcanic rock powder is mixed with a calcium source, sodium silicate, polyethylene glycol, and water, and then allowed to stand. The mixture is then heated and kept warm under continuous stirring. After the mixture is completed, a solid product is separated and dried to obtain a volcanic rock admixture.

[0009] Furthermore, in step (1), the ratio of the volcanic rock particles, nano-silica, silane coupling agent, and triethanolamine is 100 parts by weight: 20-28 parts by weight: 3.2-5 parts by weight: 2-7 parts by weight. Optionally, the silane coupling agent includes at least one of KH550, KH560, KH570, etc.

[0010] Furthermore, in step (1), the heating temperature is 50-80°C, and the pre-treated volcanic rock powder is ground to a specific surface area of ​​400-600m 2 / kg.

[0011] Furthermore, in step (2), the ratio of the pretreated volcanic rock powder to the calcium source, sodium silicate, polyethylene glycol, and water is 10g:1.5-3g:3.5-4.5g:0.03-0.05g:200-300ml. Optionally, the calcium source includes at least one of calcium nitrate, calcium chloride, and calcium acetate.

[0012] Furthermore, in step (2), the standing time is 20 to 30 minutes, so that the micropores of the pretreated volcanic rock powder can fully absorb the substances added to the water.

[0013] Furthermore, in step (2), the heating temperature is 40-55°C and the temperature is kept for 6-10 hours. The drying temperature is 70-100°C and the drying time is 1-3 hours.

[0014] Secondly, the present invention provides a preparation process of a volcanic rock admixture concrete material, comprising the following steps:

[0015] (I) Sodium silicate, polyethylene glycol, and water are uniformly mixed to form an activation solution, and then the wet material formed by the activation solution and steel slag fine aggregate is steam-cured in a closed container to obtain modified steel slag fine aggregate for standby use.

[0016] (II) Prepare the following raw materials: 170-220 parts by weight of cement, 390-510 parts by weight of coarse aggregate, 580-760 parts by weight of the modified steel slag fine aggregate, 35-55 parts by weight of the volcanic rock admixture, and 4-5 parts by weight of a water-reducing agent. Mix these raw materials thoroughly, add water at a water-cement ratio of 0.42-0.45, and stir thoroughly to obtain a concrete material.

[0017] Furthermore, in step (I), the ratio of sodium silicate, polyethylene glycol, and water is 3-4.5 g: 0.03-0.05 g: 100-150 ml.

[0018] Furthermore, in step (I), the ratio of the activation solution to the steel slag fine aggregate is 4-6 ml:10 g.

[0019] Furthermore, in step (I), the steaming treatment is carried out at a temperature of 70-85° C. for 6-8 hours.

[0020] Furthermore, in step (II), the water reducer includes any one of a polycarboxylate water reducer, a naphthalene-based water reducer, a lignin sulfonate water reducer, an aminosulfonate water reducer, a melamine-based water reducer, and the like. It should be understood that the raw materials in step (II) may also include other substances, such as fibers and defoaming agents, which can be added by technicians according to actual needs.

[0021] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0022] The present invention uses volcanic rock as raw material, mixes it with nano-silica, a silane coupling agent, and triethanolamine, and then performs a mechanical grinding pretreatment. During this process, the glassy crystals on the surface of the volcanic rock particles are destroyed, the silicon-oxygen tetrahedra depolymerize, and the silicon-oxygen bonds are broken, thereby increasing the surface reactivity of the volcanic rock particles. After further heating and reacting with a calcium source, sodium silicate, polyethylene glycol, and water, nano-hydrated calcium silicate grows in situ on the active surfaces of the volcanic rock particles. When the admixture prepared by this invention is added to concrete, these nano-hydrated calcium silicate acts as crystal nuclei to induce cement hydration, promoting the formation of cementitious components and thereby improving the early strength of the concrete. This induction also promotes deeper hydration reactions at the interface between the admixture particles and concrete, helping to strengthen the bond between the admixture particles and the concrete matrix. Furthermore, the sodium silicate solution formed by the sodium silicate and water also acts as an alkali-activated surface for the volcanic rock particles. Through this unique activation method, the present invention imparts excellent hydration reactivity to the volcanic rock particles, significantly improving the strength of concrete. Furthermore, the nano-calcium silicate hydrate formed within the volcanic rock particles during the heating reaction provides a dense filling effect, helping to alleviate the problem of volcanic rock particles, due to their porosity, absorbing mixing water after entering concrete, affecting cement hydration and adversely affecting the concrete's mechanical properties. Furthermore, the nano-silica undergoes a secondary hydration reaction with the mixing water in the concrete and the cement hydration product, calcium hydroxide, to form the calcium silicate hydrate cementitious component CSH, further enhancing the concrete's strength.

[0023] Furthermore, the present invention incorporates modified steel slag fine aggregate into the concrete material formed with the aforementioned volcanic rock admixture. Steel slag is a large-volume industrial solid waste, but the presence of free calcium oxide in steel slag can lead to poor volume stability when added to concrete, easily causing concrete cracking and limiting its large-scale use in concrete. To this end, the present invention forms an activation solution with sodium silicate, polyethylene glycol, and water, and then steam-cures the resulting wet mixture of this activation solution and steel slag fine aggregate. This not only eliminates the poor volume stability caused by the volume expansion of calcium oxide upon reaction with water to form calcium hydroxide, but also utilizes the calcium hydroxide as a calcium source to provide calcium ions, which react with other components in the activation solution to form hydrated calcium silicate particles. These particles induce cement hydration in concrete, promoting concrete strength. Furthermore, the sodium silicate solution in the activation solution also acts as an alkali-activating agent on the steel slag, destroying the silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons on the slag surface, breaking silicon-oxygen and aluminum-oxygen bonds, and increasing the hydration activity of the slag, thereby promoting concrete strength. The present invention not only effectively overcomes the problem of poor volume stability of steel slag through the above-mentioned method, but also improves the reactivity of steel slag, which is beneficial to the large-scale application of steel slag in concrete materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] It should be noted that the drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention and do not constitute an improper limitation of the present invention.

[0025] Figure 1 This is a sample of the volcanic rock admixture prepared in Example 1 below.

[0026] Figure 2 This is a test chart for the compressive strength test of Example 1 below. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention and are not intended to limit the scope of the invention. Unless otherwise defined, all professional and scientific terms used in the present invention are identical in meaning to those skilled in the art. The preferred implementation methods and materials described in the present invention are for demonstration purposes only. The reagents or raw materials used in the invention can be purchased and obtained through conventional means. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in this area or according to the product specifications. Now, in conjunction with specific embodiments, the technical scheme of the present invention will be further described.

[0028] Example 1

[0029] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0030] (1) Volcanic rock particles, nano-silica, silane coupling agent (KH550), and triethanolamine were mixed in a ratio of 100 parts by weight: 25 parts by weight: 4 parts by weight: 5.5 parts by weight, heated to 60°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 520 m 2 / kg of pre-treated volcanic rock powder, set aside.

[0031] (2) The pretreated volcanic rock powder was mixed with calcium source (calcium nitrate), sodium silicate, polyethylene glycol (PEG-2000), and water in a ratio of 10 g: 2 g: 3.5 g: 0.04: 250 ml, stirred evenly, and allowed to stand for 30 minutes. The mixture was then heated to 50° C. and kept warm for 8 hours under continuous stirring. After completion, the solid product was filtered out and dried at 90° C. for 2 hours to obtain a volcanic rock admixture (such as Figure 1 shown).

[0032] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0033] (I) Sodium silicate, polyethylene glycol (PEG-2000), and water are mixed in a ratio of 4 g:0.05 g:130 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 5 ml:10 g and stirred to form a wet material. The wet material is heated to 80°C in an autoclave and maintained at this temperature for 7 hours for steam curing. Upon completion, the modified steel slag fine aggregate is obtained and set aside.

[0034] (II) Prepare the following raw materials: 200 parts by weight of 42.5% ordinary Portland cement, 450 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 630 parts by weight of the modified steel slag fine aggregate described in this example, 50 parts by weight of the volcanic rock admixture described in this example, and 4.8 parts by weight of a polycarboxylate superplasticizer. Mix these raw materials and stir for 3 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.44 and stir for 3 minutes to obtain concrete.

[0035] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested (such as Figure 2 The result is 56.29 MPa.

[0036] Example 2

[0037] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0038] (1) Volcanic rock particles, nano-silica, silane coupling agent (KH570), and triethanolamine were mixed in a ratio of 100 parts by weight: 28 parts by weight: 5 parts by weight: 7 parts by weight, heated to 80°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 600 m 2 / kg of pre-treated volcanic rock powder, set aside.

[0039] (2) The pretreated volcanic rock powder was mixed with a calcium source (calcium nitrate), sodium silicate, polyethylene glycol (PEG-400), and water in a ratio of 10 g: 3 g: 4.5 g: 0.05: 300 ml, stirred evenly, and allowed to stand for 25 minutes. The mixture was then heated to 40°C and kept warm for 10 hours under continuous stirring. After completion, the solid product was filtered out and dried at 70°C for 3 hours to obtain a volcanic rock admixture.

[0040] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0041] (I) Sodium silicate, polyethylene glycol (PEG-400), and water are mixed in a ratio of 3 g:0.03 g:100 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 4 ml:10 g and stirred to form a wet material. The wet material is heated to 85°C in an autoclave and maintained at this temperature for 6 hours for steam curing. Upon completion, modified steel slag fine aggregate is obtained and set aside.

[0042] (II) Prepare the following raw materials: 170 parts by weight of 42.5% ordinary Portland cement, 390 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 580 parts by weight of the modified steel slag fine aggregate described in this example, 35 parts by weight of the volcanic rock admixture described in this example, and 4 parts by weight of a sodium lignin sulfonate water reducer. Mix these raw materials and stir for 3 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.42 and stir for 3 minutes to obtain concrete.

[0043] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested, and the result was 53.81 MPa.

[0044] Example 3

[0045] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0046] (1) Volcanic rock particles, nano-silica, silane coupling agent (KH560), and triethanolamine were mixed in a ratio of 100 parts by weight: 20 parts by weight: 3.2 parts by weight: 2 parts by weight, heated to 50°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 400 m 2 / kg of pre-treated volcanic rock powder, set aside.

[0047] (2) The pretreated volcanic rock powder was mixed with a calcium source (calcium chloride), sodium silicate, polyethylene glycol (PEG-400), and water in a ratio of 10 g: 1.5 g: 3.5 g: 0.03: 200 ml, stirred evenly, and allowed to stand for 20 minutes. The mixture was then heated to 55°C and kept warm for 6 hours under continuous stirring. After completion, the solid product was filtered out and dried at 100°C for 1 hour to obtain a volcanic rock admixture.

[0048] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0049] (I) Sodium silicate, polyethylene glycol (PEG-400), and water are mixed in a ratio of 4.5 g:0.04 g:150 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 6 ml:10 g and stirred to form a wet material. The wet material is heated to 70°C in an autoclave and maintained at this temperature for 8 hours for steam curing. Upon completion, the modified steel slag fine aggregate is obtained and set aside.

[0050] (II) Prepare the following raw materials: 220 parts by weight of 42.5% ordinary Portland cement, 510 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 760 parts by weight of the modified steel slag fine aggregate described in this example, 55 parts by weight of the volcanic rock admixture described in this example, and 5 parts by weight of a naphthalene-based water reducer. Mix these raw materials and stir for 5 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.45 and stir for 3 minutes to obtain concrete.

[0051] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested, and the result was 55.04 MPa.

[0052] Example 4

[0053] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0054] (1) Volcanic rock particles, nano-silica, silane coupling agent (KH550), and triethanolamine were mixed in a ratio of 100 parts by weight: 25 parts by weight: 4 parts by weight: 5.5 parts by weight, heated to 60°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 520 m 2 / kg of pre-treated volcanic rock powder, set aside.

[0055] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0056] (I) Sodium silicate, polyethylene glycol (PEG-2000), and water are mixed in a ratio of 4 g:0.05 g:130 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 5 ml:10 g and stirred to form a wet material. The wet material is heated to 80°C in an autoclave and maintained at this temperature for 7 hours for steam curing. Upon completion, the modified steel slag fine aggregate is obtained and set aside.

[0057] (II) Prepare the following raw materials: 200 parts by weight of 42.5% ordinary Portland cement, 450 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 630 parts by weight of the modified steel slag fine aggregate described in this example, 50 parts by weight of the pretreated volcanic rock powder described in this example, and 4.8 parts by weight of a polycarboxylate superplasticizer. Mix these raw materials and stir for 3 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.44 and stir for 3 minutes to obtain concrete.

[0058] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested, and the result was 40.73 MPa.

[0059] Example 5

[0060] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0061] (1) Volcanic rock particles and triethanolamine were mixed in a ratio of 100 parts by weight: 7 parts by weight, heated to 80°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 600m 2 / kg of pre-treated volcanic rock powder, set aside.

[0062] (2) The pretreated volcanic rock powder was mixed with a calcium source (calcium nitrate), sodium silicate, polyethylene glycol (PEG-400), and water in a ratio of 10 g: 3 g: 4.5 g: 0.05: 300 ml, stirred evenly, and allowed to stand for 25 minutes. The mixture was then heated to 40°C and kept warm for 10 hours under continuous stirring. After completion, the solid product was filtered out and dried at 70°C for 3 hours to obtain a volcanic rock admixture.

[0063] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0064] (I) Sodium silicate, polyethylene glycol (PEG-400), and water are mixed in a ratio of 3 g:0.03 g:100 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 4 ml:10 g and stirred to form a wet material. The wet material is heated to 85°C in an autoclave and maintained at this temperature for 6 hours for steam curing. Upon completion, modified steel slag fine aggregate is obtained and set aside.

[0065] (II) Prepare the following raw materials: 170 parts by weight of 42.5% ordinary Portland cement, 390 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 580 parts by weight of the modified steel slag fine aggregate described in this example, 35 parts by weight of the volcanic rock admixture described in this example, and 4 parts by weight of a sodium lignin sulfonate water reducer. Mix these raw materials and stir for 3 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.42 and stir for 3 minutes to obtain concrete.

[0066] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested, and the result was 44.67 MPa.

[0067] Example 6

[0068] A process for preparing a volcanic rock admixture concrete material comprises the following steps:

[0069] (I) Take the following raw materials: 200 parts by weight of 42.5 ordinary Portland cement, 450 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 630 parts by weight of steel slag fine aggregate (particle size 0.5-1.5 mm), 50 parts by weight of the volcanic rock admixture prepared in Example 1 above, and 4.8 parts by weight of polycarboxylate water reducer.

[0070] (II) The above raw materials are mixed and stirred for 3 minutes to form a mixture, and then clean water is added according to a water-cement ratio of 0.44 and stirred for 3 minutes to obtain a concrete material.

[0071] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a specimen, and then the 28d compressive strength of the specimen was tested, and the result was 36.12 MPa.

[0072] Example 7

[0073] A process for preparing a volcanic rock admixture concrete material comprises the following steps:

[0074] (I) Mix clean water and steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 6 ml:10 g to form a wet material. This wet material is heated to 70°C in an autoclave for 8 hours for steam curing. After this, the modified steel slag fine aggregate is obtained and set aside.

[0075] (II) Prepare the following raw materials: 220 parts by weight of 42.5% ordinary Portland cement, 510 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 760 parts by weight of the modified steel slag fine aggregate of this example, 55 parts by weight of the volcanic rock admixture prepared in Example 3, and 5 parts by weight of a naphthalene-based water reducer. Mix these raw materials and stir for 5 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.45 and stir for 3 minutes to obtain concrete.

[0076] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a specimen, and then the 28d compressive strength of the specimen was tested, and the result was 43.35 MPa.

[0077] Example 8

[0078] 1. A process for preparing a volcanic rock admixture, comprising the following steps:

[0079] (1) Volcanic rock particles, nano-silica, silane coupling agent (KH560), and triethanolamine were mixed in a ratio of 100 parts by weight: 20 parts by weight: 3.2 parts by weight: 2 parts by weight, heated to 50°C, and mechanically ground at the same temperature to obtain a specific surface area of ​​about 400 m 2 / kg of pre-treated volcanic rock powder, set aside.

[0080] (2) The pretreated volcanic rock powder and water were mixed in a ratio of 10 g: 200 ml, stirred evenly, and allowed to stand for 20 minutes. The mixture was then heated to 55°C and kept warm for 6 hours under continuous stirring. After completion, the solid product was filtered out and dried at 100°C for 1 hour to obtain a volcanic rock admixture.

[0081] 2. A process for preparing a volcanic rock admixture concrete material, comprising the following steps:

[0082] (I) Sodium silicate, polyethylene glycol (PEG-400), and water are mixed in a ratio of 4.5 g:0.04 g:150 ml and stirred uniformly to obtain an activation solution. The activation solution is then mixed with steel slag fine aggregate (particle size 0.5-1.5 mm) in a ratio of 6 ml:10 g and stirred to form a wet material. The wet material is heated to 70°C in an autoclave and maintained at this temperature for 8 hours for steam curing. Upon completion, the modified steel slag fine aggregate is obtained and set aside.

[0083] (II) Prepare the following raw materials: 220 parts by weight of 42.5% ordinary Portland cement, 510 parts by weight of crushed stone coarse aggregate (particle size 10-20 mm), 760 parts by weight of the modified steel slag fine aggregate described in this example, 55 parts by weight of the volcanic rock admixture described in this example, and 5 parts by weight of a naphthalene-based water reducer. Mix these raw materials and stir for 5 minutes to form a mixture. Then, add clean water at a water-cement ratio of 0.45 and stir for 3 minutes to obtain concrete.

[0084] According to GB / T 50081-2019, the concrete material prepared in this embodiment was made into a cubic specimen with a side length of 100 mm, and then the 28d compressive strength of the specimen was tested, and the result was 48.56 MPa.

[0085] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that they may modify the technical solutions described in the foregoing embodiments or substitute equivalents for some of the technical features. Any such modifications, equivalent substitutions, and improvements shall be within the scope of protection of the present invention.

Claims

1. A process for preparing a volcanic rock admixture, characterized in that: The steps include: (1) mixing volcanic rock particles, nano-silica, silane coupling agent, and triethanolamine and then mechanically grinding them under heating conditions to obtain pretreated volcanic rock powder; (2) The pretreated volcanic rock powder is mixed with a calcium source, sodium silicate, polyethylene glycol, and water, and then allowed to stand. The mixture is then heated and kept warm under continuous stirring. After the mixture is completed, a solid product is separated and dried to obtain a volcanic rock admixture.

2. The process for preparing the volcanic rock admixture according to claim 1, characterized in that: In step (1), the ratio of the volcanic rock particles, nano-silica, silane coupling agent, and triethanolamine is 100 parts by weight: 20-28 parts by weight: 3.2-5 parts by weight: 2-7 parts by weight; Optionally, the silane coupling agent includes at least one of kh550, kh560, and kh570.

3. The process for preparing the volcanic rock admixture according to claim 1, characterized in that: In step (1), the heating temperature is 50-80°C; optionally, the pre-treated volcanic rock powder is ground to a specific surface area of ​​400-600m 2 / kg.

4. The process for preparing the volcanic rock admixture according to claim 1, characterized in that: In step (2), the ratio of the pretreated volcanic rock powder to the calcium source, sodium silicate, polyethylene glycol, and water is 10g:1.5-3g:3.5-4.5g:0.03-0.05g:200-300ml; Optionally, the calcium source includes at least one of calcium nitrate, calcium chloride, and calcium acetate.

5. The process for preparing the volcanic rock admixture according to any one of claims 1 to 4, characterized in that: In step (2), the standing time is 20 to 30 minutes; Optionally, in step (2), the heating temperature is 40-55°C and the temperature is kept for 6-10 hours; Optionally, in step (2), the drying temperature is 70-100° C. and the drying time is 1-3 hours.

6. A process for preparing a volcanic rock admixture concrete material, characterized in that: The steps include: (I) mixing sodium silicate, polyethylene glycol, and water to form an activation solution, and then steam-curing the wet material formed by the activation solution and steel slag fine aggregate in a closed container to obtain modified steel slag fine aggregate for later use; (II) The following raw materials are prepared: 170-220 parts by weight of cement, 390-510 parts by weight of coarse aggregate, 580-760 parts by weight of the modified steel slag fine aggregate, 35-55 parts by weight of a volcanic rock admixture prepared by the process according to any one of claims 1 to 5, and 4-5 parts by weight of a water reducer; the raw materials are mixed, water is added at a water-cement ratio of 0.42-0.45, and the mixture is stirred uniformly to obtain a concrete material.

7. The process for preparing the volcanic rock admixture concrete material according to claim 6, characterized in that: In step (I), the ratio of sodium silicate, polyethylene glycol, and water is 3-4.5 g: 0.03-0.05 g: 100-150 ml.

8. The process for preparing the volcanic rock admixture concrete material according to claim 6, characterized in that: In step (I), the ratio of the activation solution to the steel slag fine aggregate is 4-6 ml:10 g.

9. The process for preparing the volcanic rock admixture concrete material according to claim 6, characterized in that: In step (I), the steaming treatment is carried out at a temperature of 70-85° C. for 6-8 hours.

10. The process for preparing the volcanic rock admixture concrete material according to any one of claims 6 to 9, characterized in that: In step (II), the water reducer includes any one of a polycarboxylate water reducer, a naphthalene-based water reducer, a lignin sulfonate water reducer, an aminosulfonate water reducer, and a melamine-based water reducer.

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