A super-fast-hard seawater mixing geopolymer based on sodium-aluminum ratio, and a proportioning correction and preparation method thereof

Abstract

The application discloses a kind of ultrafast hard seawater mixing based on sodium-aluminum ratio geopolymer and its proportioning correction and preparation method.The material takes metakaolin-based geopolymer as base material, by mixing quartz sand, hardening agent, chloride ion curing agent, sulfate ion curing agent and different materials, and is prepared by using seawater mixing and curing.The application controls setting time by adjusting system sodium-aluminum ratio, and uses multi-component synergistic effect to cure erosive ions, finally realizes the design purpose of early strength fast hardening and erosion resistance of geopolymer.The proportioning correction method of the ultrafast hard seawater mixing based on sodium-aluminum ratio geopolymer of the application reversely corrects mix proportion according to setting time requirement, with adjustable setting time;The preparation method of the ultrafast hard seawater mixing based on sodium-aluminum ratio geopolymer of the application has simple operation steps, does not need high-temperature forming and curing, and can be widely applied to pouring, reinforcement and repair of offshore engineering or coastal structures.

Description

Technical Field

[0001] This invention relates to the field of geopolymer-based materials technology, and in particular to an ultrafast hardening seawater-cultured geopolymer based on the sodium-aluminum ratio, and its formulation modification and preparation method. Background Technology

[0002] With the continuous advancement of my country's marine development strategy, the scale of marine engineering projects such as cross-sea bridges, port terminals, and undersea tunnels is constantly expanding. However, cement is still widely used as a cementing material in current marine engineering projects. Because the ocean is rich in various corrosive ions such as chloride, sulfate, and magnesium ions, cement performance is easily degraded, leading to a significant reduction in the durability of marine engineering structures and a marked shortening of their service life. Especially under the requirement of using locally sourced materials in marine engineering construction, the introduction of corrosive ions from raw materials becomes another source of these ions in marine concrete. Therefore, in the harsh marine environment, a high-performance cementing material with early strength, rapid hardening, and corrosion resistance becomes particularly important.

[0003] In the prior art, to solve the aforementioned technical problems, invention patent application number CN202210343761.1 discloses a method for preparing and applying a fast-setting, early-strength integrated repair and protection mortar. The technical solution is as follows: This invention uses silicate cement, sulfoaluminate cement, fly ash, ultrafine mineral powder, silica fume, quartz sand, water-reducing agent, copper-plated steel fiber, and redispersible latex powder as raw materials. First, according to the theory of closest packing, the closest packing effect of various micro and fine powders with different fineness distributions is determined. Then, typical water-cement ratio, sand-cement ratio, and mineral admixture ratio are determined to achieve the theoretical closest packing effect. Then, the integrated repair and protection mortar prepared using a dual planetary high-speed mixer has more uniform dispersion of raw materials such as graphene oxide, steel fiber, and polymer latex powder, and the mortar's microstructure is more densely combined. Vacuum treatment during the mixing of dry and wet materials effectively solves the problem of difficulty in removing air bubbles caused by the polymer latex powder during mixing. (Application number CN2021) Invention patent 10181875.6 discloses an artificial reef made of seawater-mixed fly ash geopolymer and its preparation method. The technical solution is as follows: This invention uses fly ash, slag, activators, and seashells as raw materials, possessing not only higher durability and marine ecological compatibility, but also considering the early and later strength of the artificial reef, enabling it to withstand the adverse effects of tides, waves, and currents during long-term service. Invention patent application number CN201811343935.4 discloses a seawater-mixed cement-based cementitious material. The technical solution is as follows: This invention uses micro-expansion low-heat silicate cement, limestone powder, metakaolin, silica fume, and nano-calcium carbonate as raw materials. Based on the theory of close packing, it rationally utilizes raw materials of different particle sizes and proportions. Under seawater mixing and curing conditions, the cement stone has lower alkalinity and a denser structure, effectively reducing or blocking the pathways of chemical corrosion of the mudstone and solving the problem of seawater corrosion. Application number CN202211332004 The invention patent .0 discloses a marine construction polymer material and its preparation method. The technical solution is as follows: This invention uses slag powder, finely ground basalt powder, metakaolin, lightly calcined magnesia powder, anhydrite, sea sand, fly ash microspheres, basalt short-cut fibers, microfibers, water glass, alkaline activator, composite rust inhibitor, and water-reducing agent as raw materials, effectively utilizing industrial solid waste. It not only has the characteristics of low carbon and environmental protection, high strength, and good toughness, but also has good structural density, good resistance to chloride ion penetration, good resistance to seawater corrosion, and good resistance to carbonization. The application number is CN202011161260.Patent No. 9 discloses a high-performance marine concrete with excellent durability and its preparation method. The technical solution is as follows: cement, sand, small stones, large stones, fly ash, mineral powder, silica fume, metakaolin, microspheres, water-reducing agents, and rust inhibitors are used as raw materials. By selecting coarse admixtures such as fly ash and mineral powder, and fine admixtures such as silica fume, metakaolin, and microspheres for composite addition, the prepared concrete has better density and impermeability, ultimately obtaining high-performance marine concrete with excellent durability and high strength.

[0004] Most existing invention patents combine admixtures and additives to accelerate the reaction rate and shorten the setting time, and make the system more compact and impermeable. They solve the problem of seawater erosion by physically blocking it, but there are still problems such as unadjustable setting time, low early strength, poor erosion resistance and unstable performance.

[0005] Geopolymers are inorganic polymers with an amorphous three-dimensional network structure composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra, generated under alkaline-activated conditions from industrial wastes or natural minerals containing aluminosilicates such as fly ash, slag, and metakaolin. Due to their unique structure, geopolymers possess many superior properties that are difficult for silicate cement-based materials to achieve, particularly in mechanical properties, chemical resistance, heat resistance, and the ability to cure heavy metals. However, current research on the mechanisms and applications for controlling the physicochemical properties, curing time, and workability of geopolymers still lacks in-depth mechanistic analysis, which significantly limits their widespread application.

[0006] Therefore, it is of great significance to develop an ultrafast hardening seawater genomic polymer that combines the characteristics of fast setting speed and controllable setting time, high early strength and erosion resistance. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an ultra-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio, along with its formulation modification and preparation method, exhibiting properties such as erosion resistance, rapid setting speed, and high early strength. This invention controls the setting time by adjusting the sodium-aluminum ratio of the system and employs a multi-component (mainly chloride and sulfate ion hardening agents) synergistic effect to solidify corrosive ions, ultimately achieving the designed goals of early strength, rapid hardening, and erosion resistance in the geopolymer.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] On one hand, the present invention provides an ultra-fast hardening seawater-mixed geopolymer based on a sodium-aluminum ratio, which is made from the following raw materials in parts by weight: 30-40 parts metakaolin, 20-25 parts solid water glass, 3-7 parts sodium hydroxide, 30-35 parts quartz sand, 1-4 parts hardening accelerator, 0.5-1.5 parts chloride ion curing agent, 0.3-1 part sulfate ion curing agent, 0.03-0.1 parts dispersant, 0.03-0.1 parts defoamer, and 25-30 parts seawater; wherein, metakaolin, solid water glass, and sodium hydroxide constitute the cementing material.

[0010] Preferably, the metakaolin is prepared by calcining kaolinite at 600-700℃ for 10-14 hours, followed by grinding and sieving. The prepared metakaolin contains 50-60wt% SiO2, 40-50wt% Al2O3, and has an average fineness of 1000-1500 mesh.

[0011] Preferably, the solid water glass contains 60-70 wt% SiO2, 30-40 wt% Na2O, and has an average fineness of 100-140 mesh.

[0012] Preferably, the sodium hydroxide has a purity of 99.7% or higher.

[0013] Preferably, the quartz sand has an average fineness of 40-60 mesh.

[0014] Preferably, the hardening accelerator is nano-calcium carbonate with a purity of over 98% and an average particle size of 10-100 nanometers. By mass, its content is 3-10% of the cementitious material components.

[0015] Preferably, the chloride ion curing agent is calcium nitrite with a purity of 99.7% or higher, and its content, by mass ratio, is 1-5% of the cementitious material components.

[0016] Preferably, the sulfate ion curing agent is calcined hydrotalcite, which is obtained by calcining magnesium aluminum carbonate type hydrotalcite at a temperature of 500°C, with an average particle size of 250-750 nanometers, and its content is 1-3% of the cementitious material components by mass.

[0017] Preferably, the dispersant is sodium hexametaphosphate with a purity of 99.7% or higher, and its content is 0.1-0.3% of the cementitious material component by mass ratio.

[0018] Preferably, the defoamer is a polyether defoamer with a purity of 99% or higher, and its content, by mass ratio, is 0.1-0.3% of the cementitious material component.

[0019] On the other hand, the present invention also provides a method for correcting the formulation of ultra-fast hardening seawater-based geopolymers based on the sodium-aluminum ratio, comprising the following steps:

[0020] (1) In the early stage, the mix design was carried out according to n(SiO2) / n(Al2O3), n(Na2O) / n(Al2O3) and n(H2O) / n(Na2O) (i.e., silicon-aluminum ratio, sodium-aluminum ratio and water-sodium ratio, the ratio of the three material parameters is the molar ratio of oxides). During the design process, Spearman correlation coefficient algorithm was used to analyze the dependence of geopolymer variables. It can be seen that the final setting time of geopolymer is most strongly correlated with the sodium-aluminum ratio of the system, while the correlation with the silicon-aluminum ratio of the system is not significant.

[0021] (2) The final setting time y under different sodium-aluminum ratios x was fitted using the Gaussian function curve, and the fitting function was obtained as follows:

[0022]

[0023] in, =25.63951 ± 21.72882, =1.2126 ± 0.01834, w=0.35544 ±0.38378, =-6.29424 ± 16.17087, where all symbols except x and y in the formula are coefficients and have no special meaning; the correlation coefficient is... =0.95, indicating that the curve is suitable for describing the relationship between the sodium-aluminum ratio and the final setting time of the system;

[0024] (3) Finally, the required final setting time is substituted back into the fitting function to obtain the corrected sodium-aluminum ratio of the system. The amount of sodium hydroxide and seawater is adjusted according to the corrected sodium-aluminum ratio to correct the ratio of geopolymer, thereby obtaining the formula ratio of ultra-fast hardening seawater mixed with geopolymer based on sodium-aluminum ratio.

[0025] In addition, this invention also provides a method for preparing an ultrafast hardening seawater genomic polymer based on a sodium-aluminum ratio, comprising the following steps:

[0026] (1) Weigh out 30-40 parts metakaolin, 20-25 parts solid water glass, 3-7 parts sodium hydroxide, 30-35 parts quartz sand, 1-4 parts hardening accelerator, 0.5-1.5 parts chloride ion curing agent, 0.3-1 parts sulfate ion curing agent, 0.03-0.1 parts dispersant, 0.03-0.1 parts defoamer, and 25-30 parts seawater by mass.

[0027] (2) Place the dispersant and defoamer in seawater, stir for 180-240 seconds, and then sonicate at 300-500W for 0.5-0.7 hours to obtain a uniform mixed solution.

[0028] (3) Put metakaolin, solid water glass, sodium hydroxide, quartz sand, hardening agent, chloride ion curing agent and sulfate ion curing agent into a mixing pot and dry stir for 100-120 seconds to obtain a mixture. Then add the uniform mixed solution prepared in step (2) to the above mixture and stir slowly (rotation 140±2r / min, revolution 62±2r / min) for 60-90 seconds, then stir quickly (rotation 285±3r / min, revolution 125±3r / min) for 90-120 seconds. Then pour, vibrate, and after the specimen is molded and demolded, put it in a standard curing box at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio.

[0029] The ultra-fast hardening seawater conditioning geopolymer prepared by the above method meets the following performance requirements: the flexural strength of the geopolymer is controlled to be 2-3 MPa at 30 min, 3-4 MPa at 2 h, 4-5 MPa at 3 d, and 5-6 MPa at 28 d; the compressive strength is controlled to be 20-30 MPa at 30 min, 30-40 MPa at 2 h, 40-50 MPa at 3 d, and 50-60 MPa at 28 d; the initial setting time is 5-10 min; the final setting time is 10-20 min; and the chloride ion solidification amount at 28 d is 50-60 mg·g. -1 The sulfate ion solidification amount after 28 days is 250-300 mg·g. -1 .

[0030] The inventive principle of this invention is as follows:

[0031] Metakaolin contains a large amount of highly reactive Al₂O₃ and SiO₂, resulting in a faster reaction rate compared to other aluminosilicates. The setting time of the geopolymer is strongly correlated with the sodium-aluminum ratio of the system. Within a certain range, as the sodium-aluminum ratio increases, more active SiO₄ and AlO₄ monomers are dissolved from the aluminosilicate raw materials, providing more precursors for the entire polymerization reaction, accelerating the reaction rate, shortening the setting time, and giving it the characteristic of fast hardening but not rapid setting. Simultaneously, due to the micro-expansion effect of metakaolin in the early stage of the polymerization reaction, it can, to some extent, prevent the formation of micro-shrinkage cracks in the early stage of the geopolymer gelation system, avoiding early strength reduction. However, when the sodium-aluminum ratio is too high, the rapidly generated large amount of gel will coat the metakaolin particles, hindering further geopolymerization, resulting in early strength reduction and prolonged setting time.

[0032] In addition, metakaolin-based polymers can refine the pore structure of concrete, reduce capillary content, and increase gel pore content. At the same time, they can promote the adsorption of chloride ions by hydrated calcium silicate CSH gel and hydrated calcium aluminosilicate C-(A)-SH gel through diffuse double layer interaction, and generate Friedel salt by combining chloride ions through ion exchange or precipitation. This can improve the corrosion resistance of marine concrete from two aspects: reducing chloride and sulfate ion transport channels and improving chloride ion solidification ability.

[0033] Using calcium nitrite as an additional calcium phase will effectively promote the formation of the AFm phase in the hydration products. The AFm phase can combine with chloride ions to form Friedel salt through ion exchange or precipitation, thereby giving the cementitious material a stronger chloride ion curing ability.

[0034] Layered double hydroxides (LDHs) are layered double hydroxides (LDHs) composed of positively charged metal hydroxide layers and anions stacked between them. They possess characteristics such as interlayer ion exchange, large and adjustable interlayer spacing, and large specific surface area. They can adsorb free sulfate ions from the outside environment through ion exchange, thereby achieving a solidification effect of sulfate ions and reducing the risk of concrete expansion and cracking caused by sulfate attack. Calcined layered double hydroxides (CLDHs) are obtained by calcining carbonate-type LDHs. The calcined CLDHs exhibit unique "structural memory" properties, enabling them to adsorb specific anions in an aqueous environment and restore their layered structure. This interlayer adsorption effect is more efficient than that of LDHs.

[0035] This invention combines the excellent properties of metakaolin-based polymers, calcium nitrite, and calcined hydrotalcite to develop an ultrafast hardening seawater conditioning polymer that features fast setting speed and controllable setting time, high early strength, and erosion resistance.

[0036] Compared with traditional cement-based materials, the ultra-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio has the following main advantages:

[0037] (1) The super-fast hardening seawater genomic polymer based on sodium-aluminum ratio of the present invention uses metakaolin as the main raw material, which can effectively utilize industrial waste, realize resource recycling, reduce production energy consumption and engineering cost, and meet the requirements of sustainable development strategy.

[0038] (2) The super-fast hardening seawater genomic polymer based on sodium-aluminum ratio of the present invention uses seawater as genomic water, which can effectively alleviate the problem of freshwater shortage on islands and reefs, while saving transportation costs and ensuring project progress.

[0039] (3) The present invention provides an ultra-fast hardening seawater terropolymer based on sodium-aluminum ratio, which utilizes metakaolin to rapidly transform into a three-dimensional network inorganic polymer under alkaline activation conditions, giving it excellent properties of fast setting speed and high early strength.

[0040] (4) The super-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio of the present invention uses calcium nitrite and calcined modified hydrotalcite as curing agents for chloride ions and sulfate ions, respectively. It works in synergy with aluminum-rich metakaolin to regulate the curing ability of corrosive ions, so that it has good structural density and seawater erosion resistance, which can effectively improve the durability and service life of marine engineering structures.

[0041] (5) The method for correcting the proportion of ultra-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio of the present invention is based on the strong correlation between sodium-aluminum ratio and final setting time of the system, and corrects the proportion in reverse according to the setting time requirement, which has the controllability of setting time.

[0042] (6) The preparation method of the ultra-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio of the present invention has simple operation steps, does not require high-temperature molding and curing, and can be widely used in the casting, reinforcement and repair of marine engineering or coastal structures. Detailed Implementation

[0043] The technical solutions of this invention will now be clearly and completely described in conjunction with the embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this invention.

[0044] Example 1

[0045] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 5 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, 1 part of calcium nitrite, and 0.7 parts of calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 28 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the above mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio.

[0046] Example 2

[0047] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 5 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, 0.5 parts of calcium nitrite, and 0.7 parts of calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 28 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the above mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the aforementioned ultra-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio.

[0048] Example 3

[0049] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 5 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, and 0.7 parts of calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 28 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio.

[0050] Example 4

[0051] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 5 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, 1 part of calcium nitrite, and 0.35 parts of calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 28 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the above mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio.

[0052] Example 5

[0053] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 5 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, and 1 part of calcium nitrite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 28 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the above mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio.

[0054] Example 6

[0055] In this embodiment, 34 parts of metakaolin, 23.5 parts of solid water glass, 4 parts of sodium hydroxide, 33 parts of quartz sand, 2.6 parts of nano-calcium carbonate, 1 part of calcium nitrite, and 0.7 parts of calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts of dispersant and 0.1 parts of defoamer were placed in 26 parts of seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the above mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the aforementioned ultra-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio.

[0056] Example 7

[0057] In this embodiment, 34 parts metakaolin, 23.5 parts solid water glass, 6 parts sodium hydroxide, 33 parts quartz sand, 2.6 parts nano calcium carbonate, 1 part calcium nitrite, and 0.7 parts calcined hydrotalcite were weighed and poured into a mixer. The mixture was slowly stirred for 100 seconds to obtain a mixture. Then, 0.1 parts dispersant and 0.1 parts defoamer were placed in 30 parts seawater and stirred for 180 seconds. The mixture was then ultrasonicated at 300W for 0.5 hours to obtain a uniform solution. This uniform solution was then added to the mixture and stirred slowly for 60 seconds and then quickly for 90 seconds. The mixture was then poured, vibrated, and after the specimen was molded and demolded, it was placed in a standard curing chamber at (20±2)℃ for static seawater curing to obtain the aforementioned ultra-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio.

[0058] This invention employs technical standards such as "Test Method for Strength of Cement Mortar (ISO Method)" (GB / T 17671-1999) and "Standard for Test Methods of Basic Performance of Building Mortar" (JGJ / T70-2009) to test the materials described in the above embodiments. The test results are shown in Table 1. Examples 1, 2, and 3, by changing the amount of chloride ion curing agent, and Examples 1, 4, and 5, by changing the amount of sulfate ion curing agent, collectively illustrate that the final effect of curing corrosive ions can be achieved through multi-component synergy. Examples 1, 6, and 7, by changing the amounts of sodium hydroxide and seawater, i.e., changing the sodium-aluminum ratio of the system, illustrate that adjusting the sodium-aluminum ratio of the system can achieve the final effect of controlling the setting time. As can be seen from the above embodiments, by adjusting the sodium-aluminum ratio of the system to control the setting time and employing the synergistic effect of multiple components to cure corrosive ions, the design objectives of early strength, rapid hardening, and corrosion resistance of the geopolymer can be ultimately achieved.

[0059] Table 1. Detection results of ultra-fast hardening seawater-mixed genomic polymers based on sodium-aluminum ratio.

[0060] Testing items Flexural strength at 30 minutes (MPa) 30-minute compressive strength (MPa) Flexural strength at 2 hours (MPa) 2h compressive strength (MPa) 3d flexural strength (MPa) 3D compressive strength (MPa) 28-day flexural strength (MPa) 28-day compressive strength (MPa) Final setting time / min <![CDATA[28d chloride ion solidification amount / (mg·g -1 )]]> <![CDATA[28d Sulfate ion solidification amount / (mg·g -1 )]]> Example 1 2.8 26.4 3.9 37.1 4.6 45.8 5.7 60.3 11 54 283 Example 2 2.5 21.2 3.4 35.5 4.3 43.2 5.5 56.8 14 43 257 Example 3 2.2 19.8 3.1 33.9 4.2 41.5 5.1 52.9 16 31 242 Example 4 2.6 23.3 3.7 36.8 4.5 45.5 5.4 57.1 13 49 218 Example 5 2.4 21.6 3.6 35.4 4.3 44.7 5.5 55.4 14 46 173 Example 6 2.3 21.6 3.4 33.8 4.0 41.2 5.1 52.6 16 49 237 Example 7 2.6 25.7 3.5 35.1 4.4 43.5 5.3 53.4 13 51 242

[0061] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the embodiments described. Without departing from the scope and spirit of the described embodiments, some modifications and improvements can be made by those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the claims.

Claims

1. A super-fast hardening seawater geology polymer based on sodium-aluminum ratio, characterized in that, By weight, it contains the following components: 30-40 parts metakaolin, 20-25 parts solid water glass, 3-7 parts sodium hydroxide, 30-35 parts quartz sand, 1-4 parts hardening accelerator, 0.5-1.5 parts chloride ion curing agent, 0.3-1 part sulfate ion curing agent, 0.03-0.1 parts dispersant, 0.03-0.1 parts defoamer, and 25-30 parts seawater; among which, metakaolin, solid water glass, and sodium hydroxide constitute the cementitious material. The preparation method of the ultrafast hardening seawater genomic polymer based on the sodium-aluminum ratio includes the following steps: (1) Weigh out 30-40 parts metakaolin, 20-25 parts solid water glass, 3-7 parts sodium hydroxide, 30-35 parts quartz sand, 1-4 parts hardening accelerator, 0.5-1.5 parts chloride ion curing agent, 0.3-1 parts sulfate ion curing agent, 0.03-0.1 parts dispersant, 0.03-0.1 parts defoamer, and 25-30 parts seawater by mass. (2) Place the dispersant and defoamer in seawater, stir for 180-240 seconds, and then sonicate at 300-500W for 0.5-0.7 hours to obtain a uniform mixed solution. (3) Put metakaolin, solid water glass, sodium hydroxide, quartz sand, hardening accelerator, chloride ion curing agent and sulfate ion curing agent into a mixing pot and dry stir for 100-120 seconds to obtain a mixture. Then add the uniform mixed solution prepared in step (2) to the above mixture and stir slowly for 60-90 seconds, then stir quickly for 90-120 seconds. Then pour, vibrate, and after the specimen is molded and demolded, put it into a standard curing box at (20±2)℃ for static seawater curing to obtain the super-fast hardening seawater-mixed geopolymer based on sodium-aluminum ratio. The slow stirring is specifically a rotation of 140±2 r / min and a revolution of 62±2 r / min. The fast stirring is specifically a rotation of 285±3 r / min and a revolution of 125±3 r / min. The prepared ultra-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio meets the following performance requirements: the flexural strength of the geopolymer is controlled to be 2-3 MPa at 30 min, 3-4 MPa at 2 h, 4-5 MPa at 3 d, and 5-6 MPa at 28 d; the compressive strength is controlled to be 20-30 MPa at 30 min, 30-40 MPa at 2 h, 40-50 MPa at 3 d, and 50-60 MPa at 28 d; the initial setting time is 5-10 min; the final setting time is 10-20 min; and the chloride ion solidification amount at 28 d is 50-60 mg·g. -1 The sulfate ion solidification amount after 28 days is 250-300 mg·g. -1 .

2. The ultra-fast hardening seawater genomic polymer based on sodium-aluminum ratio according to claim 1, characterized in that, The metakaolin is obtained by calcining kaolinite at 600-700℃ for 10-14 hours, followed by grinding and sieving. The metakaolin contains 50-60wt% SiO2, 40-50wt% Al2O3, and has an average particle size of 1000-1500 mesh.

3. The ultra-fast hardening seawater genomic polymer based on the sodium-aluminum ratio according to claim 1, characterized in that, The solid water glass contains 60-70 wt% SiO2 and 30-40 wt% Na2O, with an average fineness of 100-140 mesh; the sodium hydroxide has a purity of 99.7% or higher.

4. The ultra-fast hardening seawater genomic polymer based on the sodium-aluminum ratio according to claim 1, characterized in that, The average fineness of the quartz sand is 40-60 mesh.

5. The ultra-fast hardening seawater genomic polymer based on sodium-aluminum ratio according to claim 1, characterized in that, The hardening accelerator is nano-calcium carbonate with a purity of over 98% and an average particle size of 10-100 nanometers. By mass ratio, its content is 3-10% of the cementitious material components.

6. The ultra-fast hardening seawater-mixed geopolymer based on the sodium-aluminum ratio according to claim 1, characterized in that, The chloride ion curing agent is calcium nitrite with a purity of over 99.7%, and its content is 1-5% of the cementitious material component by mass ratio; the sulfate ion curing agent is calcined hydrotalcite, which is calcined from magnesium aluminum carbonate type hydrotalcite at a temperature of 500°C, with an average particle size of 250-750 nanometers, and its content is 1-3% of the cementitious material component by mass ratio.

7. The ultra-fast hardening seawater geothermic polymer based on sodium-aluminum ratio according to claim 1, characterized in that, The dispersant is sodium hexametaphosphate with a purity of 99.7% or higher, and its content is 0.1-0.3% of the cementitious material component by mass ratio; the defoamer is a polyether defoamer with a purity of 99% or higher, and its content is 0.1-0.3% of the cementitious material component by mass ratio.