阅读说明：本技术 地聚物混凝土及其制备方法 (Geopolymer concrete and preparation method thereof ) 是由 张祖华 史才军 刘翼玮 邓毓琳 于 2021-08-17 设计创作，主要内容包括：本发明涉及建筑工程技术领域,公开了一种地聚物混凝土及其制备方法。地聚物混凝土含有以下原料组分,按质量份计为：矿粉120-140份、粉煤灰40-50份、硅灰20-30份、细骨料210-230份、碱激发剂80-90份、复合减缩剂90-170份；其中,所述碱激发剂含有强碱、硅酸盐、碳酸盐和水。制备地聚物混凝土的方法包括以下步骤：(1)将强碱、硅酸盐、碳酸盐和水进行混合I得到碱激发剂；(2)将矿粉、粉煤灰、硅灰、复合减缩剂和细骨料进行混合II得到混合料；(3)将步骤(1)得到的所述碱激发剂和步骤(2)得到的所述混合料进行混合III。本发明提供的地聚物混凝土具有优良的力学和耐久性能,且生产成本低、制备过程简单。(The invention relates to the technical field of constructional engineering and discloses geopolymer concrete and a preparation method thereof. The geopolymer concrete comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer; wherein the alkali activator contains strong alkali, silicate, carbonate and water. The method for preparing geopolymer concrete comprises the following steps: (1) mixing I a strong base, silicate, carbonate and water to obtain an alkali activator; (2) mixing the mineral powder, the fly ash, the silica fume, the composite shrinkage reducing agent and the fine aggregate II to obtain a mixture; (3) and (3) mixing III the alkali activator obtained in the step (1) and the mixture obtained in the step (2). The geopolymer concrete provided by the invention has excellent mechanical and durable properties, and is low in production cost and simple in preparation process.)

1. The geopolymer concrete is characterized by comprising the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer;

wherein the alkali activator contains strong alkali, silicate, carbonate and water.

2. The geopolymer concrete according to claim 1, wherein the alkali activator is a mixture of the alkali, silicate, carbonate and water in a mass ratio of 0.2-0.5: 2-2.5: 0.1-0.3: 1.

3. the geopolymer concrete of claim 1, wherein the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate;

preferably, the silicate has a modulus of 2.5 to 3.3.

4. The geopolymer concrete of claim 1, wherein the fly ash is class I fly ash, the fine aggregate is medium sand with a particle size of 2.36mm or less, and the composite shrinkage reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite.

5. The geopolymer concrete according to any one of claims 1 to 4, wherein the raw material components of the geopolymer concrete further comprise steel fibers, and the mass parts of the steel fibers are 0 to 10 parts;

preferably, the steel fibers have a diameter of 0.1-0.3mm and a length of 4-15 mm.

6. A method of preparing geopolymer concrete comprising the steps of:

(1) mixing I a strong base, silicate, carbonate and water to obtain an alkali activator;

(2) mixing the mineral powder, the fly ash, the silica fume, the composite shrinkage reducing agent and the fine aggregate II to obtain a mixture;

(3) mixing III the alkali activator obtained in the step (1) and the mixture obtained in the step (2);

the composition comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer.

7. The method according to claim 6, wherein in the step (1), the mass ratio of the strong base, the silicate, the carbonate and the water in the alkali-activator is 0.2-0.5: 2-2.5: 0.1-0.3: 1;

preferably, the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate;

preferably, the silicate has a modulus of 2.5 to 3.3.

8. The method according to claim 6, wherein in the step (2), the fly ash is class I fly ash, the fine aggregate is medium sand with the particle size of less than or equal to 2.36mm, and the composite shrinkage reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite.

9. The method according to any one of claims 6 to 8, characterized in that the method further comprises: mixing IV the material obtained by mixing III with steel fibers, wherein the amount of the steel fibers is 0-10 parts by mass;

preferably, the steel fibers have a diameter of 0.1-0.3mm and a length of 4-15 mm;

preferably, the condition of the blend IV at least satisfies: the stirring rate was 130-150rpm for 250-350 s.

10. The method according to any one of claims 6 to 8, wherein the process of mixing I in step (1) comprises: uniformly mixing strong base, silicate, carbonate and water, and standing for 20-30 h;

preferably, the condition of mixing II in the step (2) at least satisfies: the stirring speed is 130-150rpm, and the time is 200-300 s;

preferably, the condition of the mixing III in the step (3) at least satisfies: the stirring rate was 130-150rpm for 150-200 s.

Technical Field

The invention relates to the technical field of constructional engineering, in particular to geopolymer concrete and a preparation method thereof.

Background

As the most widely applied building material in the world, the concrete brings great convenience for people and also brings very serious problems of resources, energy and environment. Usually, each ton of cement produced will be accompanied by 0.83 ton of carbon dioxide emission, which will cause the aggravation of greenhouse effect, and moreover, the production of cement also causes a great deal of harmful dust emission, serious environmental pollution, ecological balance destruction, and serious harm to the sustainable development of social and economic and the survival of human beings.

The geopolymer is a novel inorganic non-metal cementing material which is rapidly developed in recent years, is a cementing material formed by alkali excitation of low-calcium active silicon-aluminum raw materials, and has the advantages of fast setting and hardening, high early strength, high temperature resistance, acid-base salt corrosion resistance, low permeability, excellent durability and the like. Therefore, the material has huge application prospect in the aspects of building materials, high-strength materials, solid core and solid waste materials, high-temperature resistant materials and the like, and has environmental, social and economic benefits.

At present, although a relatively complete production system is formed by utilizing geopolymer to prepare concrete, the cost of the geopolymer concrete is 8-10 times that of common concrete, the reduction of the production cost becomes one of main problems which hinder the popularization and application of the geopolymer concrete, and the problem to be solved in the resource utilization of the geopolymer is urgent.

Disclosure of Invention

The invention aims to overcome the problem of high cost of preparing concrete by geopolymer in the prior art, and provides geopolymer concrete and a preparation method thereof.

In order to achieve the above object, a first aspect of the present invention provides a geopolymer concrete, which comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer; wherein the alkali activator contains strong alkali, silicate, carbonate and water.

Preferably, the alkali activator comprises the alkali, silicate, carbonate and water in a mass ratio of 0.2-0.5: 2-2.5: 0.1-0.3: 1.

preferably, the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate;

preferably, the silicate has a modulus of 2.5 to 3.3.

Preferably, the fly ash is I-grade fly ash, the fine aggregate is medium sand with the particle size of less than or equal to 2.36mm, and the composite shrinkage reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite.

Preferably, the geopolymer concrete further comprises steel fibers, wherein the steel fibers are 0-10 parts by mass;

preferably, the steel fibers have a diameter of 0.1-0.3mm and a length of 4-15 mm.

In a second aspect, the present invention provides a method of preparing geopolymer concrete, comprising the steps of:

(1) mixing I a strong base, silicate, carbonate and water to obtain an alkali activator;

(2) mixing the mineral powder, the fly ash, the silica fume, the composite shrinkage reducing agent and the fine aggregate II to obtain a mixture;

(3) mixing III the alkali activator obtained in the step (1) and the mixture obtained in the step (2);

the composition comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer.

Preferably, in the step (1), the mass ratio of the strong base, the silicate, the carbonate and the water in the alkali-activator is 0.2-0.5: 2-2.5: 0.1-0.3: 1;

preferably, the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate;

preferably, the silicate has a modulus of 2.5 to 3.3.

Preferably, in the step (2), the fly ash is class I fly ash, the fine aggregate is medium sand with a particle size of less than or equal to 2.36mm, and the composite shrinkage reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite.

Preferably, the method further comprises: mixing IV the material obtained by mixing III with steel fibers, wherein the amount of the steel fibers is 0-10 parts by mass;

preferably, the steel fibers have a diameter of 0.1-0.3mm and a length of 4-15 mm;

preferably, the condition of the blend IV at least satisfies: the stirring rate was 130-150rpm for 250-350 s.

Preferably, the process of mixing I in step (1) comprises: uniformly mixing strong base, silicate, carbonate and water, and standing for 20-30 h;

preferably, the condition of mixing II in the step (2) at least satisfies: the stirring speed is 130-150rpm, and the time is 200-300 s;

preferably, the condition of the mixing III in the step (3) at least satisfies: the stirring rate was 130-150rpm for 150-200 s.

Through the technical scheme, the invention has the beneficial effects that:

(1) the geopolymer concrete provided by the invention takes mineral powder, fine aggregate and fly ash as main raw materials, is low-carbon and clinker-free, is combined with silica fume and alkali activator, and has a more compact structure, better durability, excellent mechanical property and durability, low preparation cost, obvious economic benefit and environmental protection advantage compared with a product formed by hydrating portland cement;

(2) in the preparation process of the geopolymer concrete, strong alkali, silicate, carbonate and water are used as the alkali activator, so that the setting time of the geopolymer concrete can be effectively regulated and controlled, no water reducing agent or retarder is required to be additionally added, the preparation cost of sodium carbonate is low, and the cost of the alkali activator can be effectively reduced;

(3) according to the geopolymer concrete, a small amount of silica fume is added, the performances of large specific surface area and high particle activity of the silica fume are utilized, so that particle pores of a mixed material are filled in the preparation process, the modulus of an alkali activator is improved, the slurry fluidity is promoted, and meanwhile, the formation of C-A-S-H gel can be further promoted by combining a proper amount of silica fume with mineral powder and fly ash, so that the microstructure of the concrete is more compact, and the strength of the concrete is further improved.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect, the invention provides geopolymer concrete, which comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer; wherein the alkali activator contains strong alkali, silicate, carbonate and water.

In the invention, the mineral powder refers to high-fineness and high-activity powder obtained by processing water-quenched blast furnace slag through drying, grinding and other processes, and is divided into three grades of S105, S95 and S75 according to the national standard GB/T18046-2000, wherein the mineral powder preferably adopts S95 grade mineral powder, and the specific surface area of the mineral powder is 500-550 cm-²(ii)/g; the silicon ash refers to that when ferroalloy is used for smelting ferrosilicon and industrial silicon (metallic silicon), a large amount of SiO with strong volatility is generated in an ore-smelting electric furnace₂And Si gas which is formed by rapid oxidation, condensation and precipitation with air after the gas is discharged, wherein the preferred siliceous dust is 1800-2000cm in specific surface area²/g。

Preferably, the geopolymer concrete comprises the following raw material components in parts by mass: the mineral powder 125-135 parts may be any value in the range of 125 parts, 127 parts, 129 parts, 131 parts, 133 parts, 135 parts, and any two of these values; 42-48 parts of fly ash, specifically 42 parts, 44 parts, 46 parts and 48 parts, and any value in the range formed by any two of the above points; 22-28 parts of silica fume, specifically 22 parts, 24 parts, 26 parts and 28 parts, and any value in the range formed by any two of the above points; 215-225 parts of fine aggregate, specifically 215 parts, 217 parts, 219 parts, 221 parts, 223 parts, 225 parts, and any value in the range formed by any two of these point values; 82-88 parts of alkali activator, specifically 82 parts, 84 parts, 86 parts and 88 parts, and any value in the range formed by any two of the above points; the composite shrinkage reducing agent is 95 to 160 parts, and specifically, may be 95 parts, 105 parts, 115 parts, 125 parts, 135 parts, 145 parts, 155 parts, 160 parts, or any value in the range defined by any two of these values.

According to the invention, the alkali activator comprises the following components in a mass ratio of 0.2-0.5: 2-2.5: 0.1-0.3: 1. the inventor finds that under the preferred embodiment, the setting time of the prepared geopolymer concrete is favorably regulated and controlled, and the cost of the alkali activator is effectively reduced.

In the invention, the strong base can be any one or more strong alkali substances, the silicate can be any one or more silicate substances, and the carbonate can be any one or more carbonate substances. Preferably, the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate. The inventor finds that under the preferred embodiment, the catalysis of the alkali activator is promoted, so that the hydration reaction speed of the mixed components of the mineral powder, the fine aggregate, the fly ash and the like is accelerated.

At this time, it is further preferable that the modulus of the silicate is 2.5 to 3.3, and the modulus of the silicate means Silica (SiO)₂) With sodium oxide + potassium oxide (Na)₂O+K₂O) in terms of moles.

In the invention, the fly ash refers to tiny ash particles discharged in the combustion process of fuel (mainly coal), the particle size of the fly ash is generally between 1 and 100 mu m, and the fly ash can be divided into I grade, II grade and III grade according to the national standard GB 1596-91. Preferably, the fly ash of the invention adopts class I fly ash, and the specific surface area of the class I fly ash is 450-500cm²(ii) in terms of/g. The inventors have found that in this preferred embodiment, it is advantageous to improve the compactness and mechanical properties of geopolymer concrete.

According to the invention, the fine aggregate may be natural sand formed by the action of natural conditions, with a particle size of 5mm or less, such as river sand, natural quartz sand; or machine-made sand processed by a sand making machine and other accessory equipment. Preferably, the fine aggregate is medium sand with the grain diameter less than or equal to 2.36mm, and the bulk density of the fine aggregate is 1500-³An apparent density of 2500-3000kg/m³. The inventors have found that in this preferred embodiment it is advantageous to increase the strength of the geopolymer concrete.

According to the invention, the composite shrinkage-reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite. Illustratively, the oxyalkylene-based polymer may be an oxyethylene alcohol and/or a polyoxypropylene diol; the aluminous sulphate cement based composite may be a calcium sulphoaluminate cement based composite and/or a barium calcium sulphoaluminate cement based composite. The inventors have found that in this preferred embodiment, it is advantageous to improve the durability of geopolymer concrete.

According to the invention, the geopolymer concrete also comprises steel fibers in an amount of 0-10 parts by mass. The steel fiber is prepared by cutting thin steel wire, shearing cold-rolled steel strip, milling steel ingot or rapidly condensing molten steel to obtain fiber with length-diameter ratio of 40-80. Preferably, the steel fibers have a diameter of 0.1 to 0.3mm, and specifically may have a diameter of 0.1mm, 0.13mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, or any value in the range of any two of these points; the length is 4-15mm, specifically 4mm, 6mm, 8mm, 10mm, 13mm, 15mm, and any value in the range of any two of these point values. Further preferably, the tensile strength of the steel fiber is 2700-. The inventors have found that in this preferred embodiment it is advantageous to further improve the mechanical and durability properties of the geopolymer concrete.

In a second aspect, the present invention provides a method of preparing geopolymer concrete, comprising the steps of:

(1) mixing I a strong base, silicate, carbonate and water to obtain an alkali activator;

(2) mixing the mineral powder, the fly ash, the silica fume, the composite shrinkage reducing agent and the fine aggregate II to obtain a mixture;

(3) mixing III the alkali activator obtained in the step (1) and the mixture obtained in the step (2);

the composition comprises the following raw material components in parts by mass: 140 parts of mineral powder, 40-50 parts of fly ash, 20-30 parts of silica fume, 230 parts of fine aggregate, 80-90 parts of alkali activator and 90-170 parts of composite shrinkage reducer.

In the invention, mineral powder, fly ash, silica fume and fine aggregate can be directly used for preparing geopolymer concrete after being pretreated, wherein the pretreatment comprises grinding, drying to constant weight and the like; the mixing I, mixing II, mixing III, etc. may be carried out by a stirrer.

According to the present invention, the method for preparing geopolymer concrete may further comprise: and (3) performing die filling, molding and curing on the material obtained by mixing the III, wherein the curing can be performed at room temperature by covering and curing with a plastic film or can be performed quickly by using steam. By way of example, the specific process may be: and (3) filling the material obtained by mixing the III into a plastic mould (for example, 100 multiplied by 100mm), molding by mechanical vibration, standing for 1d in an environment with the temperature of 20 +/-5 ℃, removing the mould, placing the mould in a standard curing room with the temperature of 20 +/-2 ℃ and the relative humidity of more than 95% for curing to a specified age, or curing for 1d by using steam with the temperature of 80 ℃.

According to the invention, in the step (1), the mass ratio of the strong base, the silicate, the carbonate and the water in the alkali-activator is 0.2-0.5: 2-2.5: 0.1-0.3: 1. preferably, the strong base is sodium hydroxide and/or potassium hydroxide, the silicate is sodium silicate and/or potassium silicate, and the carbonate is sodium carbonate and/or potassium carbonate. Further preferably, the silicate has a modulus of 2.5 to 3.3.

According to the invention, in the step (2), the fly ash is class I fly ash, the fine aggregate is medium sand with the particle size of less than or equal to 2.36mm, and the composite shrinkage reducing agent is an oxyalkylene polymer and/or a sulphoaluminate cement-based composite.

According to the invention, the method further comprises: mixing IV the material obtained by mixing III with steel fibers, wherein the amount of the steel fibers is 0-10 parts by mass; preferably, the steel fibers have a diameter of 0.1-0.3mm and a length of 4-15 mm. Preferably, the condition of the blend IV at least satisfies: the stirring rate is 130-150rpm, specifically 130rpm, 135rpm, 140rpm, 145rpm, 150rpm, and any value in the range formed by any two of these values; the time is 250-350s, and specifically may be 250s, 270s, 290s, 310s, 330s, 350s, or any value in a range formed by any two of these point values.

Preferably, the process of mixing I in step (1) comprises: uniformly mixing strong base, silicate, carbonate and water, and standing for 20-30 h;

preferably, the condition of mixing II in the step (2) at least satisfies: the stirring rate is 130-150rpm, specifically 130rpm, 135rpm, 140rpm, 145rpm, 150rpm, and any value in the range formed by any two of these values; the time is 200-300s, and specifically can be 200s, 220s, 240s, 260s, 280s, 300s, and any value in the range formed by any two of these point values;

preferably, the condition of the mixing III in the step (3) at least satisfies: the stirring rate is 130-150rpm, specifically 130rpm, 135rpm, 140rpm, 145rpm, 150rpm, and any value in the range formed by any two of these values; the time is 150-200s, and specifically may be any value in the range of 150s, 170s, 190s, 210s, 230s, 250s, and any two of these values.

The present invention will be described in detail below by way of examples.

In the following examples, the fluidity of the slurry of the geopolymer concrete was measured by the method for measuring fluidity of cement mortar GB/T2419-; unless otherwise specified, commercially available products were used as the raw materials.

Example 1

(1) Mixing 0.65kg of sodium hydroxide, 4.9kg of sodium silicate, 0.63kg of sodium carbonate and 2.32kg of water, fully stirring, and standing for 24 hours to obtain an alkali activator;

(2) the specific surface area of 13kg was 530cm²(4.5 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 2.5kg of specific surface area of 1900cm²Silica fume 10kg, oxidized polyvinyl alcohol 3kg, calcium sulphoaluminate cement-based compound 22kg and river sand with particle size less than or equal to 2.36mm (bulk density 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring for 240s at a stirring speed of 140rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture at a stirring speed of 140rpm for 180s to obtain a material, mixing the material with 0.5kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture at a stirring speed of 140rpm for 300s to obtain geopolymer concrete slurry.

Example 2

(1) Mixing 0.47kg of potassium hydroxide, 4.69kg of potassium silicate, 0.7kg of potassium carbonate and 2.34kg of water, fully stirring, and standing for 20 hours to obtain an alkali activator;

(2) the specific surface area of 12.5kg was 530cm²(4.2 kg) S95 grade ore powder, with a specific surface area of 470cm²Per g of class I fly ash, 2.2kg of specific surface area of 1900cm²Silica fume per gram, 2.5kg of polyoxypropylene glycol, 7kg of calcium sulfoaluminate cement-based compound and 21.5kg of river sand with particle size less than or equal to 2.36mm (bulk density 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring for 200s at a stirring speed of 150rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture at a stirring speed of 150rpm for 150s to obtain a material, mixing the material with 0.1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture at the stirring speed of 150rpm for 250s to obtain geopolymer concrete slurry.

Example 3

(1) Mixing 1.07kg of sodium hydroxide, 5.36kg of sodium silicate, 0.22kg of sodium carbonate and 2.15kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) and (4) 13.5kg of a specific surface area of 530cm²(4.8 kg) S95 grade ore powder, with a specific surface area of 470cm²Per g of class I fly ash, 2.8kg of specific surface area is 1900cm²Silica fume per gram, 8kg of polyoxypropylene glycol, 8kg of barium calcium sulphoaluminate cement-based compound and 22.5kg of river sand (the bulk density is 1610kg/m and the particle size is less than or equal to 2.36 mm)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring at a stirring speed of 130rpm for 300s, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture at a stirring speed of 130rpm for 200s to obtain a material, mixing the material with 1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture at a stirring speed of 130rpm for 350s to obtain geopolymer concrete slurry.

Example 4

A geopolymer concrete slurry was prepared as in example 3, except that river sand was replaced with natural quartz sand having a particle size of 2.36mm or less.

Example 5

A slurry of geopolymer concrete was prepared as in example 3, except that river sand was replaced with machine-made sand with a particle size >2.36 mm.

Example 6

(1) Mixing 0.55kg of sodium hydroxide, 0.55kg of potassium hydroxide, 2.74kg of sodium silicate, 2.74kg of potassium silicate, 0.11kg of sodium carbonate, 0.11kg of potassium carbonate and 2.2kg of water, fully stirring, and standing for 30h to obtain an alkali activator;

(2) 25kg of a specific surface area of 530cm²(4 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 3kg of specific surface area of 1900cm²Silica fume 3kg of barium calcium sulphoaluminate cement-based compound and 12kg of river sand with the particle size less than or equal to 2.36mm (the bulk density is 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring for 300s at a stirring speed of 135rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture for 200s at the stirring speed of 135rpm, mixing the mixture with 0.5kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture for 350s at the stirring speed of 135rpm to obtain geopolymer concrete slurry.

Example 7

(1) Mixing 0.46kg of sodium hydroxide, 4.58kg of sodium silicate, 0.67kg of sodium carbonate and 2.34kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) the specific surface area of 12kg was 530cm²(4 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 2kg of specific surface area is 1900cm²9kg of a barium calcium sulphoaluminate cement-based compound and 21kg of river sand with a particle size of less than or equal to 2.36mm (the bulk density is 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring at the stirring speed of 145rpm for 300s, and fully and uniformly mixing to obtain a mixture;

(3) and (3) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), and stirring at the stirring speed of 145rpm for 200s to obtain geopolymer concrete slurry.

Example 8

(1) Mixing 1.1kg of sodium hydroxide, 4.48kg of sodium silicate, 1.22kg of sodium carbonate and 1.2kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) the specific surface area of 14kg was 530cm²(5 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 3kg of specific surface area of 1900cm²Silica fume 10kg, polyoxypropylene glycol 7kg, calcium sulfoaluminate cement-based compound 7kg and river sand 23kg having a particle size of 2.36mm or less (bulk density 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring for 300s at a stirring speed of 135rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture for 200s at the stirring speed of 135rpm, mixing the mixture with 1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture for 350s at the stirring speed of 135rpm to obtain geopolymer concrete slurry.

Example 9

A geopolymer concrete slurry was prepared in accordance with the procedure of example 3, except that the steel fibers having a diameter of 0.13mm, a length of 6-13mm and a tensile strength of 2850MPa were replaced with the steel fibers having a diameter of 1.2mm and a length of 40 mm.

Example 10

A geopolymer concrete slurry was prepared in the same manner as in example 3, except that basalt fiber was replaced with steel fiber having a diameter of 0.13mm, a length of 6-13mm, and a tensile strength of 2850 MPa.

Comparative example 1

(1) Mixing 1.1kg of sodium hydroxide, 5.48kg of sodium silicate and 2.2kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) the specific surface area of 14kg was 530cm²(5 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 3kg of specific surface area of 1900cm²Silica fume per gram and 23kg of river sand with the particle size of less than or equal to 2.36mm (the bulk density is 1610 kg/m)³An apparent density of 2700kg/m³) Putting into a stirrer, stirring for 300s at a stirring speed of 135rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture for 200s at the stirring speed of 135rpm, mixing the mixture with 1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture for 350s at the stirring speed of 135rpm to obtain geopolymer concrete slurry.

Comparative example 2

(1) Mixing 1.1kg of sodium hydroxide, 5.48kg of sodium silicate, 0.22kg of sodium carbonate and 2.2kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) the specific surface area of 14kg was 530cm²(5 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 3kg of specific surface area of 1900cm²Putting the silica fume of/g into a stirrer, stirring for 300s at the stirring speed of 135rpm, and fully and uniformly mixing to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture for 200s at the stirring speed of 135rpm, mixing the mixture with 1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture for 350s at the stirring speed of 135rpm to obtain geopolymer concrete slurry.

Comparative example 3

(1) Mixing 1.1kg of sodium hydroxide, 5.48kg of sodium silicate, 0.22kg of sodium carbonate and 2.2kg of water, fully stirring, and standing for 30 hours to obtain an alkali activator;

(2) the specific surface area of 14kg was 530cm²(5 kg) S95 grade ore powder with specific surface area of 470cm²Per g of class I fly ash, 3kg of specific surface area of 1900cm²Silica fume 23kg of river sand with particle size less than or equal to 2.36mm (bulk density 1610 kg/m)³An apparent density of 2700kg/m³) 0.2kg of high-performance polycarboxylate superplasticizer and 0.1kg of phosphate retarder are put into a stirrer, stirred for 300s at the stirring speed of 135rpm and fully and uniformly mixed to obtain a mixture;

(3) and (2) mixing the alkali activator obtained in the step (1) and the mixture obtained in the step (2), stirring the mixture for 200s at the stirring speed of 135rpm, mixing the mixture with 1kg of steel fibers (the diameter is 0.13mm, the length is 6-13mm, and the tensile strength is 2850MPa), and stirring the mixture for 350s at the stirring speed of 135rpm to obtain geopolymer concrete slurry.

Comparative example 4

7kg of a specific surface area of 450cm²1kg of cement having a specific surface area of 530cm²(g) S95-grade ore powder, 2kg of specific surface area 1900cm²(g) silica fume, 1.6kg of water, 0.2kg of a high-performance polycarboxylic acid water reducing agent and 0.6kg of steel fibers (diameter: 0.2mm, length: 13mm, tensile strength: 2850MPa) were put into a mixer, and stirred at a stirring rate of 135rpm for 300 seconds, followed by thorough mixing to obtain a slurry of geopolymer concrete.

Test example

1. Measurement of slurry fluidity

The slurry of geopolymer concrete obtained in example 1 to example 10 and comparative example 1 to comparative example 4 was subjected to a bench-jump test according to the test method specified in GB/T2419-.

2. Compressive Strength and carbonization depth testing

Respectively filling the geopolymer concrete slurry prepared in the examples 1-10 and the comparative examples 1-4 into two plastic moulds with the size of 100 multiplied by 100mm, forming by mechanical vibration, then standing for 1d in the environment with the temperature of 20 +/-5 ℃, removing the moulds, and then placing the moulds in a standard curing room with the temperature of 20 +/-2 ℃ and the relative humidity of more than 95% for curing to a specified age to obtain a sample I; the other was steam cured at 80 ℃ for 1d to obtain sample II.

The concrete compressive strength test was carried out on the samples I and II corresponding to examples 1 to 10 and comparative examples 1 to 4, respectively, according to the loading system specified in GB/T17671-199 Cement mortar Strength measurement, and the results are shown in Table 1.

Samples I and II corresponding to examples 1 to 10 and comparative examples 1 to 4 were placed in a laboratory environment at a relative humidity of 60% and a temperature of 20. + -. 2 ℃ for 420d, and the carbonization depth was measured, and the results are shown in Table 1.

3. Manufacturing cost estimation

The production costs of the respective concretes were compared based on comparative example 4 in consideration of the market average prices of the respective raw material components in example 1 to example 10 and comparative example 1 to comparative example 4, without considering the raw material flow costs, and the results are shown in table 1.

TABLE 1

As can be seen from the results in table 1, the geopolymer concrete prepared by the preparation method of the present invention in examples 1 to 10 has superior mechanical and durability properties and excellent working performance compared to those of comparative examples 1 to 4, while the preparation cost of examples 1 to 10 is significantly lower than that of comparative example 4 (the market mainstream super high performance concrete), and has significant economic benefits and environmental protection advantages.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.