Fly ash gel material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a fly ash gel material as well as a preparation method and application thereof. The fly ash gel material comprises fly ash, slag, gypsum, a chemical activator and a defoaming agent, the chemical exciting agent comprises alginic acid modified basalt fiber, rice hull ash and strong alkali. The fly ash gel material has the beneficial effects that the stress among coarse aggregates in high-fluidity concrete can be reduced, and the excellent deformability of concrete slurry is realized; the concentration of calcium ions in a liquid phase at the initial hydration stage of concrete slurry is controlled to generate a delayed coagulation effect, so that the compressive strength and durability of the high-fluidity concrete are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a fly ash gel material and a preparation method and application thereof. Background Art

[0002] High fluidity concrete is a concrete material with high fluidity, also known as high-flow concrete. Its characteristics are that through special additives and preparation processes, the concrete has excellent fluidity while maintaining strength and durability. This fluidity allows the concrete to easily fill every corner of the formwork, thereby achieving a self-compacting effect.

[0003] Methods for obtaining highly fluid concrete include limiting the aggregate content and using high-efficiency water-reducing agents to achieve a low water-powder ratio configuration. When concrete flows and deforms, especially when it approaches an obstacle, the aggregates move closer to each other and the internal stress increases. Studies have found that the internal stress of concrete will lead to loss of flow energy, which in turn causes blockage. The internal stress generated by coarse aggregates when concrete flows is particularly large, so limiting the amount of coarse aggregates can reduce the consumption of flow energy and reduce blockages caused by flow energy consumption. High-viscosity pastes can also reduce the high stress generated between coarse aggregates, so they can also prevent concrete from being blocked at obstacles. High-viscosity pastes can be obtained by using high-efficiency water-reducing agents to significantly reduce the water-powder ratio.

[0004] Studies have shown that the size of coarse aggregate and the clear distance from obstacles have a direct impact on the compactness of concrete, which requires the slurry to have the flow ability of liquid and the force transmission ability of solid. Sufficient deformation capacity of the slurry is a necessary condition for concrete to not require vibration. In addition, moderate viscosity and deformation capacity are also necessary conditions to ensure that the displacement of coarse aggregate is controllable and does not segregate during flow.

[0005] Using fly ash as part of the cementitious material can absorb a large amount of fly ash and realize the efficient resource utilization of fly ash; at the same time, since the amount of cement is reduced, resources and energy consumption can be saved and the environmental load can be reduced. Therefore, concrete with a large amount of fly ash is also an important development direction for green high-performance concrete. However, since the use of admixtures will affect the performance of concrete mixtures and early strength, if fly ash is to be applied to high-flow concrete without affecting the performance of the high-flow concrete, or even improving the corresponding performance, the fly ash needs to be modified. Summary of the invention

[0006] The present application provides a fly ash gel material and a preparation method and application thereof, aiming to solve the problem that the existing fly ash gel material is applied to high-flow concrete and affects its fluidity and early strength.

[0007] In a first aspect, the present application provides a fly ash gel material, comprising fly ash, slag, gypsum, a chemical activator and a defoaming agent;

[0008] The chemical activator comprises alginate-modified basalt fiber, rice husk ash and strong alkali.

[0009] According to some embodiments of the fly ash gel material described in the present application, the slag includes ironmaking blast furnace slag.

[0010] According to some embodiments of the fly ash gel material described in the present application, the defoamer includes one or more of defoamer PT-5230, defoamer ST-61 and defoamer PW-03.

[0011] According to some embodiments of the fly ash gel material described in the present application, the strong alkali includes sodium hydroxide and / or potassium hydroxide.

[0012] According to some embodiments of the fly ash gel material described in the present application, the fly ash gel material comprises the following raw materials in parts by weight: 65-75 parts of fly ash, 15-25 parts of slag, 12-15 parts of gypsum, 6-9 parts of chemical activator and 0.7-1.5 parts of defoamer;

[0013] The chemical stimulant comprises the following raw materials in parts by weight: 80-90 parts of alginate-modified basalt fiber, 1-5 parts of rice husk ash and 5-15 parts of strong alkali.

[0014] The second aspect of the present application provides a method for preparing the fly ash gel material according to the first aspect of the present application, comprising the following steps:

[0015] (1) Preparation of alginate modified basalt fiber:

[0016] a. mixing basalt fiber and alkali solution to obtain alkali-treated basalt fiber;

[0017] b. mixing the basalt fiber obtained in step a, acidified alginic acid, a Lewis acid catalyst, ethanol and water, and reacting them to obtain alginate-modified basalt fiber;

[0018] (2) Fly ash, slag, gypsum, a chemical activator, a defoaming agent and water are mixed to obtain the fly ash gel material.

[0019] According to some embodiments of the method for preparing fly ash gel material described in the present application, in step a, the length of the basalt fiber is 10-15 mm, and the diameter of the basalt fiber is 10-15 um.

[0020] According to some embodiments of the method for preparing fly ash gel material described in the present application, in step a, the alkali solution includes an aqueous sodium hydroxide solution and / or an aqueous potassium hydroxide solution; preferably, the mass concentration of the alkali solution is 5%-10%.

[0021] According to some embodiments of the method for preparing fly ash gel material described in the present application, in step a, the mass ratio of the basalt fiber to the alkali solution is 10:(3-5), the mixing temperature is 20-30°C, and the mixing time is 10-20 min.

[0022] According to some embodiments of the method for preparing the fly ash gel material of the present application, in step b, the mass ratio of the basalt fiber to the acidified alginate is 10:(2-3).

[0023] According to some embodiments of the method for preparing the fly ash gel material of the present application, the mass of the Lewis acid catalyst accounts for 2%-3% of the total mass of the basalt fiber and the acidified alginic acid.

[0024] According to some embodiments of the method for preparing the fly ash gel material described in the present application, the mass volume ratio of the basalt fiber to the ethanol is 1 g: (10-20 ml).

[0025] According to some embodiments of the method for preparing the fly ash gel material described in the present application, the volume ratio of the ethanol to the water is 3:(1-1.5).

[0026] According to some embodiments of the method for preparing fly ash gel material described in the present application, the reaction temperature is 90-105° C., and the reaction time is 4-6 hours.

[0027] According to some embodiments of the method for preparing the fly ash gel material described in the present application, the Lewis acid catalyst includes one or more of aluminum chloride, ferric chloride, titanium chloride, zinc chloride and boron trifluoride.

[0028] According to some embodiments of the method for preparing fly ash gel material described in the present application, the preparation method also includes ball milling the fly ash, slag, gypsum and chemical activator separately, and mixing the product obtained by ball milling with a defoamer and water.

[0029] According to some embodiments of the method for preparing fly ash gel material described in the present application, the specific surface areas of fly ash, slag, gypsum and chemical activator obtained after ball milling are independently 100-300m 2 / kg.

[0030] According to some embodiments of the method for preparing the fly ash gel material described in the present application, the volume mass ratio of the water to the defoaming agent is 30-40 ml: 1 g.

[0031] The third aspect of the present application provides an application of the fly ash gel material described in the first aspect of the present application or the fly ash gel material obtained by the preparation method described in the second aspect of the present application in high-flow concrete.

[0032] The fourth aspect of the present application provides a high-flow concrete, comprising the fly ash gel material described in the first aspect of the present application or the fly ash gel material obtained by the preparation method described in the second aspect of the present application.

[0033] According to some embodiments of the high-flow concrete described in the present application, it further includes coarse aggregate, fine aggregate, sulphoaluminate cement, a water reducing agent and water.

[0034] According to some embodiments of the high-flow concrete described herein, the coarse aggregate includes one or more of pebbles, gravel, basalt, limestone and granite.

[0035] According to some embodiments of the high-flow concrete described herein, the fine aggregate includes one or more of limestone fine aggregate, quartz fine aggregate, granite fine aggregate and crushed stone fine aggregate.

[0036] According to some embodiments of the high-flow concrete described in the present application, the water reducer includes one or more of an aminosulfonate-based water reducer, a fatty acid-based water reducer, and a polycarboxylate-based water reducer. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0038] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0039] An embodiment of the present application provides a fly ash gel material, comprising fly ash, slag, gypsum, a chemical stimulant and a defoaming agent; the chemical stimulant comprises alginate-modified basalt fiber, rice husk ash and a strong alkali.

[0040] The chemical activator contained in the fly ash cementitious material described in the present application creatively adopts the combination of alginate modified basalt fiber and rice husk ash, and the strong alkali adjusts the pH value of the system: compared with basalt fiber, the hydrophilicity of alginate modified basalt fiber is increased and the molecular chain is extended; after the rice husk ash encounters alkali, the lignin structural units connected by ether bonds are disconnected, and at the same time, the ester bonds connecting lignin and hemicellulose are broken due to saponification reaction, and the hydrogen bonds of the ester bonds between cellulose and hemicellulose are broken, and decomposed into monosaccharides. On the one hand, the hydroxyl groups in the sugars will form a hydrogen bond network with the remaining hydroxyl groups that have not participated in the reaction in the alginate modified basalt fiber, thereby reducing the stress between the coarse aggregates in the high-fluidity concrete and realizing the excellent deformation capacity of the concrete paste; on the other hand, the hydroxyl groups will also form unstable complexes with free calcium ions, control the concentration of calcium ions in the liquid phase at the initial stage of hydration to produce a retarding effect, and improve the compressive strength and durability of the high-fluidity concrete.

[0041] In addition, alginate-modified basalt fiber can not only utilize the compatibility of alginate structure and rice husk ash to achieve retarded setting, but also utilize the flexible dispersion of alginate in concrete to bring basalt fiber to most corners of the high-fluidity concrete, thereby improving the microporous support structure of the high-fluidity concrete and achieving resistance to concrete drying deformation.

[0042] In some embodiments of the present application, the slag includes ironmaking blast furnace slag, which is a byproduct of the ironmaking process, mainly composed of ore impurities and reduction reaction slag, and contains various oxides and silicates such as iron oxide, manganese oxide, and silicon oxide.

[0043] In some embodiments of the present application, the defoaming agent includes one or more of defoaming agent PW-03, defoaming agent ST-61 and defoaming agent PW-03; the defoaming agent described in the present application is purchased from Datian Chemical Co., Ltd.

[0044] In some embodiments of the present application, the strong base includes sodium hydroxide and / or potassium hydroxide.

[0045] In some embodiments of the present application, the following raw materials are included in parts by weight: 65-75 parts of fly ash, 15-25 parts of slag, 12-15 parts of gypsum, 6-9 parts of chemical activator and 0.7-1.5 parts of defoamer;

[0046] The chemical stimulant comprises the following raw materials in parts by weight: 80-90 parts of alginate-modified basalt fiber, 1-5 parts of rice husk ash and 5-15 parts of strong alkali.

[0047] In some embodiments of the present application, the following raw materials are included in parts by weight: 68-72 parts of fly ash, 18-22 parts of slag, 12-14 parts of gypsum, 7-8 parts of chemical activator and 0.8-1.2 parts of defoamer;

[0048] The chemical stimulant comprises the following raw materials in parts by weight: 82-88 parts of alginate-modified basalt fiber, 2-4 parts of rice husk ash and 8-12 parts of strong alkali.

[0049] In some embodiments of the present application, the following raw materials are included in parts by weight: 70 parts of fly ash, 20 parts of slag, 13 parts of gypsum, 8 parts of chemical activator and 1.0 part of defoamer;

[0050] The chemical stimulant comprises the following raw materials in parts by weight: 85 parts of alginate-modified basalt fiber, 3 parts of rice husk ash and 12 parts of strong alkali.

[0051] The present application also provides a method for preparing the fly ash gel material according to the first aspect of the present application, comprising the following steps:

[0052] (1) Preparation of alginate modified basalt fiber:

[0053] a. mixing basalt fiber and alkali solution to obtain alkali-treated basalt fiber;

[0054] b. mixing the basalt fiber obtained in step a, acidified alginic acid, a Lewis acid catalyst, ethanol and water, and reacting them to obtain alginate-modified basalt fiber;

[0055] (2) Fly ash, slag, gypsum, a chemical activator, a defoaming agent and water are mixed to obtain the fly ash gel material.

[0056] In some embodiments of the present application, in step a, the length of the basalt fiber is 10-15 mm, for example, 10 mm, 12 mm, 13 mm, 15 mm, etc., and the diameter of the basalt fiber is 10-15 um, for example, 10 um, 12 um, 13 um, 15 um, etc.

[0057] In some embodiments of the present application, in step a, the alkali solution includes an aqueous sodium hydroxide solution and / or an aqueous potassium hydroxide solution; preferably, the mass concentration of the alkali solution is 5%-10%; for example, 5%, 8%, 9%, 10%, etc.

[0058] In some embodiments of the present application, in step a, the mass ratio of the basalt fiber to the alkali solution is 10:(3-5), the mixing temperature is 20-30° C., and the mixing time is 10-20 min.

[0059] In some embodiments of the present application, in step b, the mass ratio of the basalt fiber to the acidified alginic acid is 10:(2-3);

[0060] In some embodiments of the present application, the mass of the Lewis acid catalyst accounts for 2%-3% of the total mass of the basalt fiber and the acidified alginic acid;

[0061] In some embodiments of the present application, the mass volume ratio of the basalt fiber to the ethanol is 1g:(10-20ml).

[0062] In some embodiments of the present application, the volume ratio of the ethanol to the water is 3:(1-1.5); for example, 3:1, 3:1.2, 3:1.4, 3:1.5, etc.

[0063] In some embodiments of the present application, the reaction temperature is 90-105° C., and the reaction time is 4-6 h.

[0064] In some embodiments of the present application, the Lewis acid catalyst includes one or more of aluminum chloride, iron chloride, titanium chloride, zinc chloride and boron trifluoride.

[0065] In some embodiments of the present application, the preparation method further comprises ball milling the fly ash, slag, gypsum and chemical activator respectively, and mixing the product obtained by the ball milling with a defoaming agent and water.

[0066] In some embodiments of the present application, the specific surface areas of the fly ash, slag, gypsum and chemical activator obtained after ball milling are independently 100-300m 2 / kg, for example 100m 2 / kg, 120m 2 / kg, 180m 2 / kg, 200m 2 / kg, 230m 2 / kg, 250m 2 / kg, 280m 2 / kg、300m 2 / kg, etc. The fly ash particles can be refined by ball milling, which can not only better fill the gaps in cement particles and exert the micro-aggregate effect and morphological effect, but also increase the surface energy of the powder material and reduce the energy required for its hydration reaction. Under certain conditions, since the larger the specific surface area, the smaller the particle size, when the specific surface area of ​​the fly ash particles is too large, the increase in surface activity will lead to fly ash agglomeration, thereby affecting the self-compactness of high-fluidity concrete during application. The inventors have determined through experiments that the specific surface area of ​​each raw material after ball milling is controlled at 100-300m 2 / kg range can make the performance of high-fluidity concrete reach the best.

[0067] In some embodiments of the present application, the volume mass ratio of the water to the defoaming agent is 30-40 ml: 1 g.

[0068] In some embodiments of the present application, the product obtained by ball milling is mixed with the defoaming agent and water for 10-20 minutes, and the mixing speed is 100-200 r / min.

[0069] The embodiments of the present application also provide an application of the fly ash gel material described in the first aspect of the present application or the fly ash gel material obtained by the preparation method described in the second aspect of the present application in high-flow concrete.

[0070] The embodiment of the present application also provides a high-flow concrete, comprising the fly ash gel material described in the first aspect of the present application or the fly ash gel material obtained by the preparation method described in the second aspect of the present application. The fly ash gel material described in the present application is applied to the high-flow concrete to reduce the adverse effects of the initial hydration heat of the high-flow concrete, improve the pore structure and fluidity, increase the density of the concrete, reduce drying deformation, and improve durability and compressive strength.

[0071] In some embodiments of the present application, coarse aggregate, fine aggregate, sulphoaluminate cement, water reducing agent and water are also included.

[0072] In some embodiments of the present application, the high-flow concrete includes the following components in parts by weight: 300-400 parts of coarse aggregate, 250-450 parts of fine aggregate, 150-200 parts of sulphoaluminate cement, 50-70 parts of water reducer, 200-300 parts of fly ash cementitious material and 200-300 parts of water.

[0073] In some embodiments of the present application, the coarse aggregate includes one or more of pebbles, gravel, basalt, limestone and granite.

[0074] In some embodiments of the present application, the fine aggregate includes one or more of limestone fine aggregate, quartz fine aggregate, granite fine aggregate and crushed stone fine aggregate;

[0075] In some embodiments of the present application, the water reducer includes one or more of aminosulfonate-based water reducers, fatty acid-based water reducers, and polycarboxylate-based water reducers.

[0076] In some embodiments of the present application, the preparation process of the high-flow concrete comprises the following steps:

[0077] Step 1: Mix the coarse aggregate and the fine aggregate according to weight, and stir evenly to obtain an aggregate mixture;

[0078] Step 2: uniformly mixing sulphoaluminate cement, water reducing agent, fly ash cementitious material and water to obtain a gel composition;

[0079] Step 3: Add the gel composition into the aggregate mixture and mix them evenly to obtain the high-fluidity concrete.

[0080] The technical solution of the present application is further described below in conjunction with specific embodiments.

[0081] Example 1

[0082] A fly ash gel material comprises the following raw materials in parts by mass: 65 parts of fly ash, 15 parts of ironmaking blast furnace slag, 12 parts of gypsum, 6 parts of chemical stimulant, and 0.7 parts of defoaming agent (PT-5230); the chemical stimulant has the following mass proportion: 80% of alginate modified basalt fiber, 5% of rice husk ash, and 15% of sodium hydroxide.

[0083] The preparation method of fly ash gel material comprises the following steps: ball milling the fly ash, slag, gypsum and chemical activator in the above mass parts for 2 hours respectively to make the specific surface area of ​​the fly ash gel material be 200-300m 2 / kg; then the ball-milled materials were mixed for 10 minutes until uniform to obtain a mixture. The above mass parts of defoamer PT-5230 were dissolved in water (the volume mass ratio of water to defoamer was 30ml:1g) and added to the above mixture, stirred at a stirring speed of 100r / min for 15 minutes, stirred uniformly to obtain a fly ash gel material and cured for 28 days.

[0084] The preparation method of the alginate modified basalt fiber comprises the following steps: soaking the short-cut basalt fiber with a fiber length of 15 mm and a fiber diameter of 15 um in a sodium hydroxide solution with a mass concentration of 5% at 25°C for 20 minutes (wherein the mass ratio of the short-cut basalt fiber to the sodium hydroxide solution is 10:3), and then ultrasonically cleaning it with ethanol and deionized water for 3 times respectively; preparing a mixed solution of 100 parts of ethanol and water (the volume ratio of ethanol to water is 3:1), adding 10 parts of the above-treated basalt fiber to the mixed solution and stirring, and then adding 2 parts of acidified alginate and 0.36 parts of ferric chloride, and reacting under heating and reflux for 5 hours; after the reaction is complete, filtering and washing to obtain the alginate modified basalt fiber.

[0085] Example 2

[0086] The fly ash gel material described in Example 2 is different from that in Example 1 only in that the mass fractions of each raw material contained in the fly ash gel material in Example 2 are different from those in Example 1.

[0087] The specific steps are:

[0088] A fly ash gel material comprises the following raw materials in parts by mass: 70 parts of fly ash, 20 parts of ironmaking blast furnace slag, 13 parts of gypsum, 7 parts of chemical stimulant, and 1.0 part of defoamer (PT-5230); the chemical stimulant has the following mass proportion: 85% of alginate modified basalt fiber, 5% of rice husk ash, and 10% of sodium hydroxide.

[0089] The preparation method of fly ash gel material comprises the following steps: ball milling the fly ash, slag, gypsum and chemical activator in the above mass parts for 2 hours respectively to make the specific surface area of ​​the fly ash gel material be 200-300m 2 / kg; then the ball-milled materials were mixed for 10 minutes until uniform to obtain a mixture. The above mass parts of defoamer PT-5230 were dissolved in water (the volume mass ratio of water to defoamer was 30ml:1g) and added to the above mixture, stirred at a stirring speed of 100r / min for 15 minutes, stirred uniformly to obtain a fly ash gel material and cured for 28 days.

[0090] The preparation method of the alginate modified basalt fiber comprises the following steps: soaking the short-cut basalt fiber with a fiber length of 15 mm and a fiber diameter of 15 um in a sodium hydroxide solution with a mass concentration of 5% at 25°C for 20 minutes (wherein the mass ratio of the short-cut basalt fiber to the sodium hydroxide solution is 10:3), and then ultrasonically cleaning it with ethanol and deionized water for 3 times respectively; preparing a mixed solution of 100 parts of ethanol and water (the volume ratio of ethanol to water is 3:1), adding 10 parts of the above-treated basalt fiber to the mixed solution and stirring, and then adding 2 parts of acidified alginate and 0.36 parts of ferric chloride, and reacting under heating and reflux for 5 hours; after the reaction is complete, filtering and washing to obtain the alginate modified basalt fiber.

[0091] Example 3

[0092] The fly ash gel material described in Example 3 is different from that in Example 1 only in that the mass fractions of each raw material contained in the fly ash gel material in Example 3 are different from those in Example 1.

[0093] The specific steps are:

[0094] A fly ash gel material comprises the following raw materials in parts by mass: 75 parts of fly ash, 25 parts of ironmaking blast furnace slag, 15 parts of gypsum, 9 parts of chemical stimulant, and 1.5 parts of defoaming agent (PT-5230); the chemical stimulant has the following mass proportion: 90% of alginate modified basalt fiber, 2% of rice husk ash, and 8% of sodium hydroxide.

[0095] The preparation method of fly ash gel material comprises the following steps: ball milling the fly ash, slag, gypsum and chemical activator in the above mass parts for 2 hours respectively to make the specific surface area of ​​the fly ash gel material be 200-300m 2 / kg; then the ball-milled materials were mixed for 10 minutes until uniform to obtain a mixture. The above mass parts of defoamer PT-5230 were dissolved in water (the volume mass ratio of water to defoamer was 30ml:1g) and added to the above mixture, stirred at a stirring speed of 100r / min for 15 minutes, stirred uniformly to obtain a fly ash gel material and cured for 28 days.

[0096] The preparation method of the alginate modified basalt fiber comprises the following steps: soaking the short-cut basalt fiber with a fiber length of 15 mm and a fiber diameter of 15 um in a sodium hydroxide solution with a mass concentration of 5% at 25°C for 20 minutes (wherein the mass ratio of the short-cut basalt fiber to the sodium hydroxide solution is 10:3), and then ultrasonically cleaning it with ethanol and deionized water for 3 times respectively; preparing a mixed solution of 100 parts of ethanol and water (the volume ratio of ethanol to water is 3:1), adding 10 parts of the above-treated basalt fiber to the mixed solution and stirring, and then adding 2 parts of acidified alginate and 0.36 parts of ferric chloride, and reacting under heating and reflux for 5 hours; after the reaction is complete, filtering and washing to obtain the alginate modified basalt fiber.

[0097] Example 4

[0098] The only difference between Example 4 and Example 1 is that the specific surface area of ​​the fly ash, slag, gypsum and chemical activator obtained after ball milling in the preparation process of the fly ash gel material in Example 5 is greater than 300m 2 / kg.

[0099] Comparative Example 1

[0100] The difference between Comparative Example 1 and Example 1 is that the chemical activator in the fly ash gel material of Comparative Example 1 includes 85% of alginate modified basalt fiber and 15% of sodium hydroxide.

[0101] Comparative Example 2

[0102] A fly ash cementitious material comprises the following raw materials in mass fractions: 75 parts of fly ash, 25 parts of ironmaking blast furnace slag, 15 parts of gypsum, 9 parts of chemical activator, and 1.5 parts of defoaming agent (PT-5230); the mass proportion of the chemical activator is as follows: 92% of alginate modified basalt fiber, 2% of rice husk ash, and 6% of sodium hydroxide, and the remaining operations are the same as those in Example 3.

[0103] Comparative Example 3

[0104] The difference between Comparative Example 3 and Example 1 is that the chemical activator in the fly ash gel material of Comparative Example 3 includes 90% rice husk ash and 15% sodium hydroxide.

[0105] Comparative Example 4

[0106] The difference between Comparative Example 4 and Example 1 is that the chemical activator in the fly ash gel material of Comparative Example 4 includes 80% of alginate modified glass fiber, 5% of rice husk ash and 15% of sodium hydroxide.

[0107] The preparation method of alginate modified glass fiber is the same as the preparation method of alginate modified basalt fiber.

[0108] Comparative Example 5

[0109] The difference between Comparative Example 5 and Example 1 is that the chemical activator in the fly ash gel material of Comparative Example 5 includes 80% of alginate modified polypropylene fiber, 5% of rice husk ash, and 15% of sodium hydroxide.

[0110] The preparation method of alginate modified polypropylene fiber is the same as the preparation method of alginate modified basalt fiber.

[0111] The performance test results of the fly ash gel materials described in Examples 1-4 and Comparative Examples 1-5 of the present application are shown in Table 1:

[0112] Table 1

[0113]

[0114] Note: The final setting time test of the embodiment of the present application is carried out in accordance with the national standard GB / T1346-2011 "Test Method for Water Consistency, Setting Time and Stability of Cement Standard Consistency";

[0115] The compressive strength test is carried out in accordance with "Test method for strength of cement mortar (ISO method)" GB / T 17617-199.

[0116] It can be seen from Table 1 that the fly ash cementitious material of the present application has a short setting time and high compressive strength. Compared with Example 3, the specific surface area of ​​each raw material after ball milling in Example 4 is greater than 300m 2 / kg, the setting time of the obtained fly ash cementitious material is shortened and the compressive strength is reduced. This may be due to the agglomeration of the obtained fly ash cementitious material, which leads to a shortened setting time. In addition, there are gaps between the particles, which leads to insufficient density and the inability to obtain the ideal compressive strength.

[0117] In Comparative Examples 1 and 3, the chemical stimulants used either lack alginate modified basalt fibers or lack rice husk ash, and the setting time of the fly ash gel material obtained is shortened or prolonged, which is not conducive to application. It can be seen that in the chemical stimulant, alginate modified basalt fibers and rice husk ash are indispensable. In Comparative Example 2, the percentage of alginate modified basalt fibers used is too high. Although the setting time of the fly ash gel material obtained is increased, its compressive strength is not as good as that of Examples 1-4. It can be seen that the amount of alginate modified basalt fibers in the chemical stimulant needs to be controlled at 80-90%.

[0118] The results of Comparative Examples 3-4 show that when the fibers in the alginate modified fibers are replaced with glass fibers or polypropylene fibers, the ideal setting time and compressive strength cannot be obtained. It can be seen that in the technical solution described in the present invention, only alginate modified basalt fibers are more suitable.

[0119] The application of the fly ash gel material described in Examples 1-4 and Comparative Examples 1-5 of the present application in high-flow concrete is studied.

[0120] Application Example 1

[0121] A high-flow concrete comprises the following components in parts by weight: 300 parts of coarse aggregate, 250 parts of fine aggregate, 150 parts of sulphoaluminate cement, 50 parts of sodium aminobenzenesulfonate, 300 parts of the fly ash cementitious material described in Example 1, and 200 parts of water.

[0122] The preparation method comprises the following steps:

[0123] Step 1: Mix the coarse aggregate and the fine aggregate according to the above weight parts, stir evenly, and obtain an aggregate mixture;

[0124] Step 2: Evenly mix sulphoaluminate cement, water reducing agent sodium aminobenzenesulfonate, the fly ash cementitious material described in Example 1 and water to obtain a gel composition;

[0125] Step 3: Add the gel composition to the aggregate composition and mix them evenly to obtain the high-flow concrete.

[0126] Application Example 2

[0127] The difference between Application Example 2 and Application Example 1 is that the high-flow concrete described in Application Example 2 uses the fly ash cementitious material described in Example 2 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0128] Application Example 3

[0129] The difference between Application Example 3 and Application Example 1 is that the high-flow concrete described in Application Example 3 uses the fly ash cementitious material described in Example 3 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0130] Application Example 4

[0131] The only difference between Application Example 4 and Application Example 1 is that the high-flow concrete described in Application Example 4 uses the fly ash cementitious material described in Example 4 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0132] Application Example 5

[0133] The only difference between Application Example 5 and Application Example 1 is that the high-flow concrete described in Application Example 5 uses the fly ash cementitious material described in Comparative Example 1 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0134] Application Example 6

[0135] The only difference between Application Example 6 and Application Example 1 is that the high-flow concrete described in Application Example 6 uses the fly ash cementitious material described in Comparative Example 2 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0136] Application Example 7

[0137] The only difference between Application Example 7 and Application Example 1 is that the high-flow concrete described in Application Example 7 uses the fly ash cementitious material described in Comparative Example 3 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0138] Application Example 8

[0139] The only difference between Application Example 8 and Application Example 1 is that the high-flow concrete described in Application Example 8 uses the fly ash cementitious material described in Comparative Example 4 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0140] Application Example 9

[0141] The only difference between Application Example 9 and Application Example 1 is that the high-flow concrete described in Application Example 9 uses the fly ash cementitious material described in Comparative Example 5 instead of the fly ash cementitious material described in Example 1, and the rest of the operations are the same as those in Application Example 1.

[0142] The performance study of the high fluidity concrete described in Application Examples 1-9 is shown in Table 2:

[0143] Table 2

[0144] Strength level Fluidity / mm V-funnel passing time / s 28d compressive strength (MPa) Application Example 1 C60 407 8.9 50.9 Application Example 2 C60 391 9.2 51.4 Application Example 3 C60 387 10.5 52.7 Application Example 4 C60 395 10.1 48.9 Application Example 5 C45 354 10.9 47.7 Application Example 6 C60 371 11.6 48.1 Application Example 7 C45 319 10.5 46.8 Application Example 8 C45 332 10.8 47.1 Application Example 9 C45 345 11.0 47.8

[0145] Note: In the present application, the fluidity and mechanical properties of concrete samples were tested in accordance with the specifications of GB / T 50080 "Standard for Test Methods for Properties of Ordinary Concrete Mixtures" and GB / T50010 "Specification for Design of Concrete Structures".

[0146] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A fly ash gel material, characterized in that: Includes fly ash, slag, gypsum, chemical activators and defoamers; The chemical activator comprises alginate-modified basalt fiber, rice husk ash and strong alkali.

2. The fly ash gel material according to claim 1, characterized in that: The slag includes iron-making blast furnace slag; And / or, the defoamer includes one or more of defoamer PT-5230, defoamer ST-61 and defoamer PW-03; And / or, the strong base includes sodium hydroxide and / or potassium hydroxide.

3. The fly ash gel material according to claim 1, characterized in that: The method comprises the following raw materials in parts by weight: 65-75 parts of fly ash, 15-25 parts of slag, 12-15 parts of gypsum, 6-9 parts of chemical activator and 0.7-1.5 parts of defoamer; The chemical stimulant comprises the following raw materials in parts by weight: 80-90 parts of alginate-modified basalt fiber, 1-5 parts of rice husk ash and 5-15 parts of strong alkali.

4. The method for preparing the fly ash gel material according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Preparation of alginate modified basalt fiber: a. mixing basalt fiber and alkali solution to obtain alkali-treated basalt fiber; b. mixing the basalt fiber obtained in step a, acidified alginic acid, a Lewis acid catalyst, ethanol and water, and reacting them to obtain alginate-modified basalt fiber; (2) Fly ash, slag, gypsum, a chemical activator, a defoaming agent and water are mixed to obtain the fly ash gel material.

5. The method for preparing fly ash gel material according to claim 4, characterized in that: In step a, the length of the basalt fiber is 10-15 mm, and the diameter of the basalt fiber is 10-15 um; And / or, in step a, the alkali solution comprises a sodium hydroxide aqueous solution and / or a potassium hydroxide aqueous solution; preferably, the mass concentration of the alkali solution is 5%-10%; And / or, in step a, the mass ratio of the basalt fiber to the alkali solution is 10:(3-5), the mixing temperature is 20-30° C., and the mixing time is 10-20 min.

6. The method for preparing fly ash gel material according to claim 4, characterized in that: In step b, the mass ratio of the basalt fiber to the acidified alginic acid is 10:(2-3); and / or, the mass of the Lewis acid catalyst accounts for 2%-3% of the total mass of the basalt fiber and the acidified alginic acid; and / or, the mass volume ratio of the basalt fiber to the ethanol is 1 g:(10-20 ml); And / or, the volume ratio of the ethanol to the water is 3:(1-1.5); And / or, the reaction temperature is 90-105°C, and the reaction time is 4-6h; And / or, the Lewis acid catalyst includes one or more of aluminum chloride, iron chloride, titanium chloride, zinc chloride and boron trifluoride.

7. The method for preparing fly ash gel material according to claim 4, characterized in that: The preparation method further comprises ball-milling fly ash, slag, gypsum and a chemical activator respectively, and mixing the product obtained by ball-milling with a defoamer and water; Preferably, the specific surface areas of the fly ash, slag, gypsum and chemical activator obtained after ball milling are independently 100-300m 2 / kg; Preferably, the volume mass ratio of the water to the defoaming agent is 30-40 ml: 1 g.

8. Use of the fly ash gel material according to any one of claims 1 to 3 or the fly ash gel material obtained by the preparation method according to any one of claims 4 to 7 in high-flow concrete.

9. A high-flow concrete, characterized in that: It comprises the fly ash gel material described in any one of claims 1 to 3 or the fly ash gel material obtained by the preparation method described in any one of claims 4 to 7.

10. The high-flow concrete according to claim 9, characterized in that: It also includes coarse aggregate, fine aggregate, sulphoaluminate cement, water reducing agent and water; Preferably, the coarse aggregate comprises one or more of pebbles, gravel, basalt, limestone and granite; Preferably, the fine aggregate includes one or more of limestone fine aggregate, quartz fine aggregate, granite fine aggregate and crushed stone fine aggregate; Preferably, the water reducer includes one or more of a sulfamate-based water reducer, a fatty acid-based water reducer and a polycarboxylate-based water reducer.

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