Geopolymer environment-friendly adhesive mortar and preparation method thereof

Abstract

The invention relates to geopolymer environment-friendly adhesive mortar and a preparation method thereof. The method comprises the following steps: 1, preparing a sodium hydroxide solution and a water glass solution at least 1 day ahead; 2, weighing the fly ash, the slag powder, the cellulose ether, the latex powder, the fibers, the zinc sulfate and the fine sand according to the weight parts; 3, pouring into a stirrer, and stirring at a low speed to obtain a precursor; and 4, mixing the alkali solution obtained in the step 1 with a water reducing agent to obtain a mixed solution. And 5, stirring the precursor obtained in the step 3 for 30-60 seconds, pouring the mixed solution obtained in the step 4, continuously stirring at a low speed for 30-60 seconds, and stirring at a high speed for 120-180 seconds to obtain the geopolymer environment-friendly adhesive mortar. The invention solves the technical problems of weak binding power, low brittleness, high cost, and poor water resistance and freeze-thaw cycle resistance of the traditional external wall insulation board binding mortar.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and particularly to a novel geopolymer environmental protection bonding mortar and a preparation method thereof. Background Art

[0002] The bonding mortar connecting the wall body and the external thermal insulation board is one of the main reasons for the detachment of the external wall thermal insulation system. The existing external wall thermal insulation board bonding mortar is mostly made by mixing organic glue and cement mortar, which has the characteristics of strong bonding force and low brittleness. However, due to the presence of organic polymers, there are also problems such as high cost, poor water resistance and freeze-thaw cycle resistance, and easy aging. There is an urgent need to develop an inorganic bonding mortar with high bonding strength and high durability.

[0003] The main cementitious materials in the existing cement mortar and polymer mortar are both cement, which has the problem of high carbon emissions. Promote green building materials, highlighting the requirements of building use functions as well as energy conservation, material conservation and environmental protection. Developing green and low-carbon cementitious materials that can replace cement is of great significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a geopolymer environmental protection bonding mortar to solve the technical problems of weak bonding force, low brittleness, high cost, poor water resistance and freeze-thaw cycle resistance existing in the traditional external wall thermal insulation board bonding mortar.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions.

[0006] A geopolymer environmental protection bonding mortar comprises the following components in parts by weight: Fly ash: 40 - 60 parts; Ground granulated blast-furnace slag: 40 - 60 parts; Cellulose ether: 0.2 - 0.4 part; Redispersible polymer powder: 2 - 4 parts; Zinc sulfate: 1 - 1.5 parts; Fiber: 0.1 - 0.25 part; Water-reducing agent: 1 - 1.5 parts; Alkali solution: 50 - 55 parts; Fine sand: 150 - 200 parts.

[0007] Preferably, the fly ash is secondary fly ash, the density of the fly ash ≤ 2.5 g / cm , , , ,

[0006] , 2 , ,

[0005] , ,

[0004] , , , , ,

[0008] , , 3 ,

[0007] , , , , the loss on ignition is 5% - 6%; the calcium oxide content is 3 - 10% wt, 12% < 45 μm, and the sieve residue < 30%.

[0008] Preferably, the basicity coefficient M0 of the ground granulated blast-furnace slag ≥ 1, the mass coefficient ≥ 2, the specific surface area is 400 - 480 m 2 / kg, and the density ≥ 2.8 g / cm3 。

[0009] Preferably, the fiber is made of polypropylene fiber or composite fiber, and the length of the fiber is 3-6 cm; the composite fiber includes basalt fiber, PVA fiber and nanocellulose; 0.05-0.1 parts of basalt fiber; 0.03-0.1 parts of PVA fiber; 0.02-0.05 parts of nanocellulose.

[0010] Preferably, the cellulose ether is hydroxypropyl methyl cellulose ether or hydroxyethyl methyl cellulose ether; the methoxy content of hydroxypropyl methyl cellulose ether is 28-30%wt, and the hydroxypropoxy content is 7-12%wt; the methoxy content of hydroxyethyl methyl cellulose ether is 16.5%-20%wt, and the hydroxyethoxy content is 1.5%-9.5%wt.

[0011] Preferably, the latex powder is VAE latex powder or acrylate latex powder or vinyl acetate-ethylene-higher fatty acid vinyl ester terpolymer latex powder or ethylene-vinyl chloride-vinyl laurate terpolymer latex powder; the solid content of VAE latex powder ≥98%, and the particle size is about 150 μm.

[0012] Preferably, the solid content of the zinc sulfate ≥99%, and the pH value is 4.4-6.0.

[0013] Preferably, the water reducing agent is polycarboxylate water reducing agent or naphthalene series water reducing agent or bio-based water reducing agent; the chloride ion content in the polycarboxylate water reducing agent ≤0.6, the sodium sulfate content ≤5.0, and the pH value is 5.0-7.0; The alkali solution is prepared by mixing sodium hydroxide solution, water glass and water; The fine sand is river sand, the particle size distribution is 0.075-0.3 mm, the fineness modulus is 1.5-2.0, and the moisture content is about 0.2%.

[0014] A preparation method of a geopolymer environmental protection bonding mortar includes the following steps.

[0015] Step 1, prepare the sodium hydroxide solution and the water glass solution at least 1 day in advance.

[0016] Step 2, weigh fly ash, slag powder, cellulose ether, latex powder, fiber, zinc sulfate and fine sand according to parts by weight.

[0017] Step 3, then pour it into a mixer and stir at a low speed to obtain a precursor.

[0018] Step 4, mix the alkali solution obtained in Step 1 with the water reducing agent to obtain a mixed solution.

[0019] Step 5: After the precursor obtained in Step 3 starts stirring for 30 - 60 s, pour in the mixed solution prepared in Step 4. Continue stirring at a low speed for 30 - 60 s, and then stir at a high speed for 120 - 180 s to obtain the geopolymer environmental protection bonding mortar.

[0020] Compared with the prior art, the present invention has the following features and beneficial effects.

[0021] 1. The geopolymer environmental protection bonding mortar of the present invention. The geopolymer in this bonding mortar has the advantages of waste utilization, high early strength, acid and alkali corrosion resistance, and good high-temperature resistance. The hydration reaction of the geopolymer cementitious material is different from that of cement. There is less high-calcium mineral composition such as tricalcium silicate in the geopolymer. After alkali activation and polycondensation reaction, a large amount of C-(A)-S-H and N-(A)-S-H substances with a spatial network structure are finally generated. Compared with the large amount of calcium hydroxide (CH) generated by cement hydration, these substances are more likely to establish a dense transition zone structure with the aggregate or the old interface. Therefore, compared with cement, it shows higher adhesiveness. At the same time, the present invention uses solid waste and develops an environmental protection bonding mortar with high adhesiveness and high durability through alkali activation technology, solving the cracking problem at the connection between the wall panel and the external wall insulation board, which is necessary and feasible. The purpose of the present invention is to develop a low-cost, low-carbon environmental protection, high-adhesion, and high-durability GP inorganic mortar using solid waste in view of the easy falling-off problem of external wall external insulation and the deficiencies of the existing bonding mortar. To achieve the above purpose, research on the influence of factors such as cellulose ether, latex powder, fiber, nano-materials, and the ratio of alkali solution on the comprehensive performance of the bonding mortar has been carried out.

[0022] 2. All the solid powder raw materials of the geopolymer environmental protection bonding mortar of the present invention use solid waste. In the formula, the proportion of fly ash (40 - 60 parts) and slag powder (40 - 60 parts) reaches 100%, and both are industrial wastes. There is no need to exploit natural resources, reducing carbon emissions by about 80%, meeting the green building material standards (such as LEED certification requirements). Fly ash adopts Class II F fly ash (calcium oxide 3 - 10%wt, loss on ignition 5 - 6%) to activate the silicon-aluminum activity through the pozzolanic effect and improve the geopolymer gel strength. The slag powder characteristics adopt S95 grade slag powder (specific surface area 400 - 480 m 2 / kg) to provide calcium components and promote the formation of C-(N)A-S-H hybrid structure. At the same time, combined with the low-carbon preparation process, the alkali activation reaction (10 mol / L NaOH + water glass) does not require high-temperature calcination, and the energy consumption is only 20% of that of traditional cement, and there is no CO2 emission during the production process, having environmental protection and resource recycling. 3. The geopolymer environmental protection bonding mortar of the present invention has high bonding strength and crack resistance; among them, the fibers can be compounded with basalt fibers (alkali resistance), PVA fibers (inhibiting plastic shrinkage) and nanocellulose, so that the 28-day tensile bonding strength ≥ 1.0 MPa and the flexural fracture toughness is increased by 50%. The polycarboxylate water reducer (chloride ion ≤ 0.6%) improves the density, and the 28-day compressive strength reaches 45-55 MPa. The microporous structure of fly ash reduces the CO2 permeability, and the carbonation depth is only 40% of that of ordinary cement, with high durability and corrosion resistance. Zinc sulfate (pH 4.4-6.0) and the three-dimensional network structure of geopolymer act synergistically, and the strength loss is ≤ 10% after soaking in 5% sulfuric acid for 30 days, with good chemical erosion resistance.

[0023] 4. In the geopolymer environmental protection bonding mortar of the present invention, the water reducer can be a bio-based water reducer (sodium sulfate ≤ 2.0%) and cellulose ether (hydroxypropoxy 7-12%wt) to synergistically improve the water retention, and the fluidity reaches 180-220 mm, with good construction performance. Nanocellulose (0.02-0.05 parts) fills the pores, and the hardening shrinkage rate is reduced by 60%, with strong anti-shrinkage performance. The alkali activation system (sodium silicate modulus 1.8-2.2) shortens the setting time, and the 4-hour strength reaches 70% of the final strength.

[0024] 5. Through innovations such as solid waste resource utilization, fiber composite reinforcement, and optimization of the alkali activation system, the present invention realizes the coordinated improvement of environmental protection (carbon emissions reduced by 80%), high performance (compressive strength 45~55 MPa), durability (acid corrosion resistance, high temperature resistance) and construction convenience (rapid hardening). Its core value lies in converting industrial waste into high-performance building materials and promoting the transformation of the construction industry to a low-carbon circular economy. Specific embodiments

[0025] Example 1 The weight part composition ratio of the geopolymer environmental protection bonding mortar is as follows: 50 parts of fly ash; the fly ash is of Class F secondary, with a density of 2.4 g / cm 3 , loss on ignition 5.5%, calcium oxide content 6%wt, 45μm sieve residue 15%; 50 parts of slag powder; the slag powder is of S95 grade, with a specific surface area of 450 m 2 / kg, basicity coefficient M0 = 1.2, mass coefficient 2.3; 0.4 part of cellulose ether; the cellulose ether is of hydroxypropyl methyl type, with methoxy 29%wt and hydroxypropoxy 9%wt; 2 parts of latex powder; the latex powder is VAE latex powder, with a solid content ≥ 98% and a particle size of about 150μm; 1 part of zinc sulfate, with a solid content of zinc sulfate 99.5% and pH = 5.0; 0.15 parts of fiber; the fiber is a composite fiber with a length of 3 - 6 cm; 1 part of water reducing agent; the water reducing agent is polycarboxylic acid type, with chloride ion content ≤ 0.5%, sodium sulfate ≤ 4.0%, and pH = 6.0; 55 parts of alkali solution; the alkali solution is a mixture of 10 mol / L NaOH solution and water glass, and the 10 mol / L NaOH solution and water glass are in a ratio of 1:3; 200 parts of fine sand; the fine sand is river sand with a particle size of 0.075 - 0.3 mm, fineness modulus of 1.8, and water content of 0.2%.

[0026] Example 2 The weight part composition ratio of the geopolymer environmental protection bonding mortar is as follows: 60 parts of fly ash; the fly ash is Class F secondary, with a density of 2.4 g / cm 3 , loss on ignition of 5.5%, calcium oxide content of 6% wt, and 45 - μm sieve residue of 15%; 40 parts of slag powder; the slag powder is S95 grade, with a specific surface area of 420 m 2 / kg, basicity coefficient M0 = 1.1, and mass coefficient of 2.1; 0.35 parts of cellulose ether; the cellulose ether is hydroxypropyl methyl, with methoxy of 29% wt and hydroxypropoxy of 9% wt; 4 parts of latex powder; the latex powder is VAE latex powder, with a solid content ≥ 98% and a particle size of about 150 μm; 1 part of zinc sulfate; the zinc sulfate has a solid content of 99.5% and a pH of 5.0; 0.1 part of fiber; the fiber is a composite fiber with a length of 3 - 6 cm; 1 part of water reducing agent; the water reducing agent is polycarboxylic acid type, with chloride ion content ≤ 0.5%, sodium sulfate ≤ 4.0%, and pH = 6.0; 50 parts of alkali solution; the alkali solution is a mixture of 10 mol / L NaOH solution and water glass, and the 10 mol / L NaOH solution and water glass are in a ratio of 1:3; 150 parts of fine sand; the fine sand is river sand with a particle size of 0.075 - 0.3 mm, fineness modulus of 1.8, and water content of 0.2%.

[0027] Example 3 The weight part composition ratio of the geopolymer environmental protection bonding mortar is as follows: 40 parts of fly ash; the fly ash is Class F secondary, with a density of 2.4 g / cm 3 , loss on ignition of 5.5%, calcium oxide content of 6% wt, and 45 - μm sieve residue of 15%; 60 parts of slag powder; the slag powder is S95 grade, with a specific surface area of 420 m 2 / kg, basicity coefficient M0 = 1.1, mass coefficient 2.1; 0.25 parts of cellulose ether; the cellulose ether is of the hydroxypropyl methyl type, with methoxy group 29%wt and hydroxypropoxy group 9%wt; 2.5 parts of latex powder; the latex powder is VAE latex powder, with solid content ≥ 98% and particle size about 150μm; 1.5 parts of zinc sulfate; the solid content of zinc sulfate is 99.2%, pH = 5.5; 0.25 parts of fiber; the fiber is composite fiber, with length 3 - 6 cm; 1.5 parts of water reducing agent; the water reducing agent is of the polycarboxylic acid type, with chloride ion content ≤ 0.5%, sodium sulfate ≤ 4.0%, pH = 6.0; 55 parts of alkali solution; the alkali solution is a mixture of 10mol / L NaOH solution and water glass, and the 10mol / L NaOH solution and water glass are proportioned by mass ratio of 1:3; 180 parts of fine sand; the fine sand is river sand, with particle size of the river sand 0.075 - 0.3mm, fineness modulus 1.8, and water content 0.2%.

[0028] Preparation method of the geopolymer environmental protection bonding mortar in Examples 1 - 3: Prepare sodium hydroxide solution and water glass solution 24 hours in advance, and let it stand for defoaming. Mix fly ash, slag powder, cellulose ether, latex powder, fiber, zinc sulfate, and fine sand and stir at low speed (60r / min, 60s) to form a precursor. After mixing the alkali solution and the water reducing agent, add them to the precursor in two times, first stir at low speed (60s) and then stir at high speed (120s). Make the prepared mortar into standard test specimens, and put the demolded bonding mortar specimens into a standard curing room with temperature 20 ± 2°C and relative humidity 90% for compressive and flexural strength tests; put them into a standard curing room with temperature 20 ± 2°C and relative humidity 50% for tensile bonding strength tests.

[0029] I. Core comparison of ratio differences

[0030] II. Comparison of performance indicators III. Influence of ratio on potential performance <opposite text> IV. Influence mechanism of key components 1. Ratio of fly ash (FA) to slag (GGBS) Example 1 (FA50:GGBS50): Balance the reaction rate and cost, and the "micro-aggregate effect" of fly ash is complementary to the activity of slag.

[0031] Example 2 (FA60:GGBS40): A high proportion of fly ash results in a slower initial reaction, but the pozzolanic effect is enhanced in the later stage, requiring a longer curing period.

[0032] Example 3 (FA40:GGBS60): The high activity of slag accelerates the polycondensation of geopolymers, generating more C-(A)-S-H gels and improving the density.

[0033] 2. Dosage and type of cellulose ether (HPMC) Example 2 (HPMC 0.35 parts): A high dosage enhances water retention but reduces fluidity. Increase the dosage of VAE (4 parts) and reduce the dosage of fine sand (150 parts) to compensate for fluidity.

[0034] Example 3 (HPMC 0.25 parts): A low dosage has low water retention and increased fluidity. Rely on the high activity of slag and the activation of alkali solution to increase strength, and use a higher amount of fine sand (180 parts) and a higher fiber dosage (0.25 parts) to inhibit water evaporation.

[0035] 3. Synergy of latex powder and fiber Example 2 (latex powder 4 parts + fiber 0.1 part): A high dosage of latex powder improves flexibility and increases fluidity. Since fly ash has good crack resistance, the fiber dosage is reduced; at the same time, the dosage of alkali solution is reduced to improve strength.

[0036] Example 3 (latex powder 2.5 parts + fiber 0.25 part): The dosage of latex powder is relatively low, relying on the high activity of slag and the mechanical interlocking of fine sand to maintain bond strength.

[0037] 4. Ratio of water reducer and fine sand Example 1 (water reducer 1 part + fine sand 200 parts): Medium water reducer, matching medium-active powder, increasing the liquid-solid ratio to improve fluidity, supplemented with medium dosages of fine sand and medium amounts of fiber to ensure crack resistance.

[0038] Example 3 (fine sand 180 parts + water reducer 1.5 parts): More slag, high activity, a relatively high proportion of fine sand, reducing shrinkage pores, increasing the water reducer to ensure fluidity.

[0039] V. Application scenarios In summary, through the differential design of the fly ash / slag ratio, fiber-water reducer-fine sand system, and latex powder dosage, the three examples have achieved targeted optimization of construction conditions, durability requirements, and cost control while ensuring consistent core mechanical properties (compressive strength ≥ 45 MPa, bond strength ≥ 1.0 MPa, sulfuric acid corrosion resistance ≤ 10% loss). In actual applications, the ratio should be selected according to the engineering scenario, and if necessary, the dosage of zinc sulfate or fiber can be fine-tuned to further adapt to special requirements.

[0040] Certainly, in other embodiments, when the mortar is used for high-performance structural functions such as bridge joints and prefabricated building nodes, as well as chemical plant floors and marine concrete repairs, composite fibers can also be used. The length of the fibers is 3-6 cm; the composite fibers include basalt fibers, PVA fibers, and nanocellulose; 0.05-0.1 parts of basalt fibers; 0.03-0.1 parts of PVA fibers; 0.02-0.05 parts of nanocellulose, so as to exert the high flexural strength and fatigue resistance characteristics of the composite fibers. In the fiber system, basalt fibers (0.05-0.1 parts) have excellent alkali resistance, PVA fibers (0.03-0.1 parts) inhibit plastic shrinkage cracks, and nanocellulose (0.02-0.05 parts) improves the micro-density through nano-scale filling; specifically, 0.05 parts of chopped carbon fibers can also be introduced on the basis of the above composite fibers to improve crack resistance and toughness at high temperatures and optimize the fiber dispersion process (such as adding in the pre-mixed sand stage).

[0041] Certainly, in other embodiments, when the mortar is used for low-temperature thin-layer construction or engineering scenarios with high fluidity requirements, hydroxyethyl methyl cellulose ether can be used. The methoxy content of hydroxyethyl methyl cellulose ether is 16.5% - 20% wt, and the hydroxyethoxy content is 1.5% - 9.5% wt.

[0042] Certainly, in other embodiments, the latex powder can also be vinyl acetate-ethylene-higher fatty acid vinyl ester terpolymer latex powder or ethylene-vinyl chloride-vinyl laurate terpolymer latex powder or VAE latex powder.

[0043] When the mortar is applied to conventional buildings: vinyl acetate-ethylene-higher fatty acid vinyl ester terpolymer latex powder is preferably used, taking into account both bond strength and water resistance.

[0044] When the mortar is applied to corrosive areas, ethylene-vinyl chloride-vinyl laurate terpolymer latex powder is preferably selected.

[0045] When the mortar is applied to dry environments, temporary projects, or cost-sensitive projects, VAE latex powder is preferably selected. The solid content of VAE latex powder is ≥98%, and the particle size is about 150 μm.

[0046] Of course, in other embodiments, the water reducer can also be a naphthalene-based water reducer or a bio-based water reducer. The naphthalene-based water reducer is preferably used in temporary projects below C30 with low requirements for early strength. The bio-based water reducer is suitable for ecological projects and mass concrete, and early strength agents (such as sodium sulfate) and nano-silica are required to improve the early strength. The chloride ion content in the bio-based water reducer (such as modified lignosulfonate) is ≤0.3%, sodium sulfate ≤2.0%, the pH value is neutral, and it has better compatibility with the geopolymer system. If a high water reduction rate (above 40%) is required, a nano-composite polycarboxylate water reducer can also be used. The nano-composite polycarboxylate water reducer contains 1%-2% nano-SiO2, which simultaneously improves the density and impermeability.

[0047] In the geopolymer environmental protection bonding mortar of the present invention, fly ash is a solid waste generated by industries such as thermal power plants, metallurgy, and chemical engineering; slag powder is the residue after blast furnace ironmaking. Both industrial wastes can react as precursors under the action of an alkali activator. In the geopolymer system, fly ash and slag powder are used as the main cementitious materials. Among them, fly ash can improve the fluidity of the paste; the incorporation of slag can shorten the setting time of the geopolymer; cellulose ether can improve the crack resistance and mechanical properties of the bonding mortar; latex powder can improve the bonding performance of the bonding mortar; fibers can improve the crack resistance and durability, and inhibit shrinkage; zinc sulfate can delay the setting speed of the bonding mortar; polycarboxylate water reducer can enhance the fluidity of the bonding mortar and improve the performance of the bonding mortar; the alkali activator is prepared by mixing sodium hydroxide, water glass, and water.

[0048] The above embodiments are not an exhaustive list of specific implementation manners, and there may be other embodiments. The above embodiments are intended to illustrate the present invention, rather than limiting the protection scope of the present invention. All applications obtained by simple changes of the present invention fall within the protection scope of the present invention.

Claims

1. An environmentally friendly geopolymer bonding mortar, characterized in that, It contains the following components in parts by weight: Fly ash: 40 - 60 parts; Ground granulated blast-furnace slag: 40 - 60 parts; Cellulose ether: 0.2 - 0.4 part; Redispersible polymer powder: 2 - 4 parts; Zinc sulfate: 1 - 1.5 parts; Fiber: 0.1 - 0.25 part; Water-reducing agent: 1 - 1.5 parts; Alkali solution: 50 - 55 parts; Fine sand: 150 - 200 parts.

2. The geopolymer environmental protection bonding mortar according to claim 1, characterized in that: The fly ash is Class II fly ash, and the density of the fly ash ≤ 2.5 g / cm 3 , the loss on ignition is 5% - 6%; the calcium oxide content is 3 - 10% wt, the particle size of 12% of the fly ash < 45 μm, and the sieve residue < 30%.

3. The geopolymer environmental protection bonding mortar according to claim 1, characterized in that: The basicity coefficient M0 of the slag powder is ≥ 1, the quality coefficient is ≥ 2, the specific surface area is 400 - 480 m 2 / kg, and the density is ≥ 2.8 g / cm 3 .

4. The geopolymer environmental protection bonding mortar according to claim 1, wherein: The fiber is polypropylene fiber or composite fiber, and the length of the fiber is 3 - 6 cm; the composite fiber includes basalt fiber, PVA fiber and nano-cellulose; basalt fiber is 0.05 - 0.1 part; PVA fiber is 0.03 - 0.1 part; Nano-cellulose is 0.02 - 0.05 part.

5. The geopolymer environmental protection bonding mortar according to claim 1, characterized in that: The cellulose ether is hydroxypropyl methyl cellulose ether or hydroxyethyl methyl cellulose ether; the methoxy content of hydroxypropyl methyl cellulose ether is 28 - 30%wt, and the hydroxypropoxy content is 7 - 12%wt; the methoxy content of hydroxyethyl methyl cellulose ether is 16.5% - 20%wt, and the hydroxyethoxy content is 1.5% - 9.5%wt.

6. The geopolymer environmental protection bonding mortar according to claim 1, characterized in that: The redispersible polymer powder is VAE redispersible polymer powder or acrylate redispersible polymer powder or vinyl acetate-ethylene-higher fatty acid vinyl ester terpolymer redispersible polymer powder or ethylene-vinyl chloride-vinyl laurate terpolymer redispersible polymer powder; the solid content of VAE redispersible polymer powder ≥98%, and the particle size is about 150μm.

7. The geopolymer environmental protection bonding mortar according to claim 1, wherein: The solid content of the zinc sulfate ≥99%, and the pH value is 4.4 - 6.

0.

8. The geopolymer environmental protection bonding mortar according to claim 1, characterized in that: The water-reducing agent is polycarboxylate water-reducing agent or naphthalene series water-reducing agent or bio-based water-reducing agent; the chloride ion content in the polycarboxylate water-reducing agent ≤0.6, the sodium sulfate content ≤5.0, and the pH value is 5.0 - 7.0; The alkali solution is prepared by mixing sodium hydroxide solution, water glass and water; The fine sand is river sand, the particle size distribution is 0.075 - 0.3mm, the fineness modulus is 1.5 - 2.0, and the water content is about 0.2%.

9. The preparation method of the geopolymer environmental protection bonding mortar according to any one of claims 1-8, characterized in that, It includes the following steps: Step 1, prepare sodium hydroxide solution and water glass solution at least 1 day in advance; Step 2, weigh fly ash, ground granulated blast-furnace slag, cellulose ether, redispersible polymer powder, fiber, zinc sulfate and fine sand according to parts by weight; Step 3, then pour them into a mixer and stir at low speed to obtain a precursor; Step 4, mix the alkali solution obtained in Step 1 with the water-reducing agent to obtain a mixed solution; Step 5, after the precursor obtained in Step 3 starts to be stirred for 30 - 60s, pour the mixed solution prepared in Step 4, continue to stir at low speed for 30 - 60s, and then stir at high speed for 120 - 180s to obtain the geopolymer environmental protection bonding mortar.

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