A single-component ultra-fast hard polymer grouting material based on self-heating and a ratio correction method

Abstract

The present invention provides a single-component ultra-fast hardening geopolymer grouting material based on self-heating and a method for correcting the proportions. First, the approximate proportions of the single-component alkali-activated material are determined to achieve the ultra-fast hardening, early hardening, and high-strength performance of the single-component geopolymer. Using a solid raw material formula, kaolin, quartz sand, calcium ion activator, fiber, etc. are designed as material A according to the proportions, and solid water glass, caustic soda, retarder, etc. are designed as material B according to the proportions. When used, it is only necessary to mix material A and material B evenly, add water and continue stirring until it is in a fluid state to carry out road and building repairs. The single-component geopolymer powder will generate obvious hydration reaction heat when used, which can produce an effect similar to thermal curing, and promote geopolymerization reaction, so that its strength develops rapidly. It has the characteristics of ultra-fast hardening, early hardening, and high strength. The correction method proposed in the present invention can enable the single-component geopolymer to meet the requirements of self-heating and has a high application value.

Description

Technical Field

[0001] The invention relates to the field of rapid road repair and reinforcement, and in particular to a self-heating single-component ultra-fast hardening metakaolin-based polymer grouting material and a ratio correction method. Background Art

[0002] Geopolymer is a novel inorganic silica-alumina cementitious material composed of [SiO4] and [AlO4] tetrahedra, alternately linked by shared oxygen atoms, forming a three-dimensional network structure. Compared to traditional cement-based materials, it offers superior properties such as high strength, frost resistance, impermeability, high temperature resistance, corrosion resistance, and fire resistance. Its production energy consumption is only 10-30% of that of ordinary Portland cement. Therefore, the widespread use of geopolymer cementitious grouting can significantly reduce carbon emissions, meeting national requirements for energy conservation, emission reduction, and green and sustainable development.

[0003] Currently, geopolymer repair materials typically consist of two components: a precursor rich in silica and aluminum phases and a highly alkaline liquid activator. However, the alkali-activated solution must be prepared in advance and is highly viscous, corrosive, and toxic. This makes transportation difficult and poses significant safety risks in practical engineering applications. Replacing the liquid alkali activator with a solid alkali activator to create a single-component geopolymer is a current research hotspot. Similar to ordinary Portland cement, single-component geopolymers can be applied simply by adding water and aggregate. Furthermore, compared to two-component geopolymers, single-component geopolymers offer higher early strength and a higher heat of hydration.

[0004] Regarding the preparation of single-component geopolymer materials, Patent 201110405630.3 describes a single-component geopolymer cementitious material prepared from calcined clay, and Patent 201210238413 describes a single-component geopolymer cementitious material prepared from calcined clay and limestone with the addition of alkali. However, both require temperatures above room temperature to harden, making them inconvenient to use. Patent 201210410858.6 proposes a single-component alkali-activated cement that hardens at room temperature after calcination, and Patent 201810541139.5 further proposes a single-component alkali-activated cement that hardens at room temperature without calcination. However, both of these materials have slow hardening times and low ultimate strength, making them unsuitable for high-strength applications or emergency repair environments. The single-component geopolymers covered in these patents primarily focus on mix ratio research, and do not address the calculation and design of geopolymer mix ratios beyond these ratio studies. Summary of the Invention

[0005] The present invention aims to provide a self-heating, single-component, ultra-fast hardening geopolymer grouting material and a mix correction method. The material is simple to prepare and easy to use, exhibiting ultra-fast hardening, early hardening, and high-strength properties. It can achieve sufficient strength within 30 minutes and subsequently achieve stable strength growth, possessing high application value in the field of road repair. The mix design correction formula described in the present invention can effectively integrate mix ratio research and utilize the self-heating properties of single-component geopolymers, possessing broad application prospects and considerable research reference value.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] One of the technical solutions of the present invention is a single-component ultra-fast hard polymer grouting material based on self-heating, which is divided into two components: component A and component B.

[0008] Component A, calculated by weight percentage: metakaolin 46%-52%, quartz sand 40%-50%, synthetic fiber 0.2%, inorganic retarder 0.1-0.2%, calcium ion activator 3.4%-4%, slag 2-6%, aluminum tripolyphosphate reinforcing agent 0.2%, the sum of the weight percentages of each raw material being 100%; on this basis, component A also contains 1.5‰ nano-reinforcement agent;

[0009] Component B is calculated by weight as follows: water glass 70%-78%, solid sodium hydroxide 7%-15%, quartz sand 5%-15%, retarder powder 0.5-3%, water reducer 0.3%, and the sum of the weight percentages of each raw material is 100%;

[0010] When using, after mixing component A and component B, add water and stir; among them, the mass fraction of component B accounts for 40%~60% of the mass fraction of component A, and the mass of added water accounts for 40%~50% of the mass fraction of component A; and the environmental factors and material factors should be comprehensively considered to ensure that the self-heating factor T is between 2 and 4.5.

[0011] In the above technical solution, further, the component B is an alkali activator, wherein the modulus of water glass is 2.1-2.3, and the modulus of the alkali activator prepared by using water glass and caustic soda is 1.4-1.6.

[0012] Furthermore, the mesh number of the metakaolin is not less than 1250 meshes, and the mesh number of the quartz sand is 40-120 meshes.

[0013] Furthermore, the water glass is powdered instant sodium silicate with a mesh size of ≥100 meshes.

[0014] Furthermore, the calcium ion activator can be provided by calcium ion-containing substances such as calcium hydroxide, calcium oxide and nano-calcium carbonate, and the weight percentage is the effective mass of CaO.

[0015] Furthermore, the synthetic fiber is one or more of PVA fiber and PP fiber, and specifically 3mm PVA short fiber can be used.

[0016] Furthermore, the nano-enhancer is one or more of carbon nanotubes and nano-silicon oxide.

[0017] Furthermore, the retarder in the material B is sodium hexametaphosphate powder with a purity of 98%.

[0018] Furthermore, the water reducer is one or both of a powdered naphthalene water reducer and a powdered aliphatic water reducer. The preferred solution is to mix the naphthalene water reducer and the aliphatic water reducer in a ratio of 2:1.

[0019] The second technical solution of the present invention is to further modify the ratio of the self-heating single-component ultra-fast hard geopolymer grouting material according to the formula described above. The geopolymer ratio can be modified according to the formula after changes in raw material components and environmental factors. The modification steps are as follows:

[0020] Step 1: Determine the self-heating factor

[0021] Measure the ambient temperature, obtain the ambient temperature parameter, and substitute it into the formula for calculation; query the hydration heat of the hydration exothermic material, obtain the mass of the hydration exothermic material based on the ratio, and substitute it into the formula for calculation; obtain the mass of component A and component B based on the ratio; calculate Na / Al and Si / Al based on the XRF analysis results; measure the material temperature and substitute it into the following formula to calculate the self-heating factor:

[0022]

[0023] Among them, the hydration exothermic substance in the second item is caustic soda, quicklime and other substances that can make water boil when hydrated; Na / Al and Si / Al in the third item are the molar ratios of Na2O, Al2O3 and SiO2 in caustic soda, water glass, metakaolin and slag.

[0024] Step 2: Calculate correction parameters

[0025] Compare the calculated self-heating factor T to see if it is within the range of 2-4.5, and obtain the correction parameter α according to the following formula:

[0026] When T<2, the correction parameter α=2-T;

[0027] When T>4.5, the correction parameter α=T-4.5;

[0028] Step 3: Correct the ratio according to the correction formula:

[0029] When other substances and temperature factors are determined, adjusting the amount of caustic soda can change the mass of the hydration exothermic substance and the Na / Al ratio. Therefore, the caustic soda mass is adjusted and trial calculations are performed until the requirements are met. Substitute the correction parameters into the correction formula for trial calculations. Calculate the caustic soda mass that needs to be changed and satisfy the following relationship:

[0030] When T<2:

[0031] ;

[0032] When T>4.5:

[0033]

[0034] Furthermore, the self-heating factor T should be in the range of 2 to 4.5. If it is lower than 2, the self-heating requirement cannot be met. If it is too high, the synthesis of silica-alumina monomer gel will affect the reaction.

[0035] Furthermore, the self-heating factor T can be adjusted by increasing the material temperature.

[0036] Technical solution three of the present invention: The method for preparing the above-mentioned single-component ultra-fast hard polymer grouting material based on self-heating comprises the following steps:

[0037] The raw materials are weighed in proportion, and the components in the component A are preliminarily mixed for 2 to 3 minutes. The components in the component B are preliminarily mixed for 2 to 3 minutes. The mixed components A and B are mixed and stirred for 1 to 2 minutes, and water is added and stirred for 2 minutes to obtain the ultra-fast hardening polymer grouting material.

[0038] The inventive principle of the present invention is:

[0039] Compared to other active materials such as fly ash, metakaolin, as a geopolymer precursor, offers advantages such as fewer impurities, higher reactivity, more uniform and stable products, and superior mechanical properties. However, when used as a precursor, metakaolin reacts similarly to conventional thermosetting materials, with curing temperature significantly affecting its polymerization reaction. Within a certain range, higher curing temperatures enhance the degree of reaction and significantly accelerate its setting and hardening rate. Considering that after mixing the precursor with an alkaline activator, some of the powder releases a certain amount of heat upon hydration, the hydration heat in the early stages of the reaction is much higher than that of a two-component geopolymer, significantly increasing the geopolymer reaction rate. The present invention takes into account the reaction characteristics of some geopolymer cementitious materials, allowing the exothermic reaction of the geopolymer reaction, which relies on its own solid dissolution and polymerization reaction, to provide a thermal foundation for the reaction itself, providing thermal excitation conditions. This significantly increases the geopolymer reaction rate and provides higher early strength for the cementitious material. Furthermore, a formula relationship between the Si, Al, and Na components and the self-heating condition is proposed, which provides a reference for accelerating reactions using the hydration heat of single-component geopolymers.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The early high-strength ultra-fast hard polymer grouting material prepared by the present invention can reach initial setting in 10 minutes and final setting in 20 minutes, and has a compressive strength of ≥15Mpa at 40 minutes, a compressive strength of ≥25Mpa at 2 hours, and a compressive strength of ≥35Mpa at 3 days. No water seepage occurs, and the fluidity is ≥270mm after stirring is completed. It has good thixotropic properties and its fluidity can be greatly improved under mechanical vibration.

[0042] (2) In the preferred embodiment of the present invention, the use of calcium phase minerals to activate the geopolymer grouting material can significantly improve its early strength and enable it to harden quickly. The use of barium chloride and sodium hexametaphosphate as retarders prevents the geopolymer grouting material from false setting in a high temperature environment, improves the working performance of the geopolymer grouting material, and shortens the setting time.

[0043] (3) The grouting material of the present invention can be added with tap water or seawater. Compared with cement and organic cementitious materials, the alkali-activated material is relatively insensitive to chloride ions in seawater and can react with heavy metal ions. Experimental verification shows that the strength of the grouting material is improved in the early, middle and late stages when using seawater.

[0044] (4) The ultra-fast hard polymer grouting material prepared by the present invention has the advantages of simple operation method, easy production, convenient use, convenient transportation, fast coagulation and hardening, and high strength, and has great use value in the field of engineering emergency repair.

[0045] (5) The ultrafast hard geopolymer prepared by the present invention effectively utilizes the hydration heat of part of the material to promote the reaction process, and improves its working performance by adding a retarder to prevent it from setting too quickly. It can obtain higher strength in the early stage of the reaction, which has great advantages in reducing construction time and carrying out emergency repairs.

[0046] (6) The present invention proposes a self-heating geopolymer ratio formula, which quantitatively corrects the single-component geopolymer ratio design and has certain research value for geopolymer ratio design. DETAILED DESCRIPTION

[0047] To make the use and features of the present invention more clearly understood, the following embodiments are given for detailed description. Unless otherwise specified, the methods of the present invention are all conventional methods in the art.

[0048] In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed, and the values ​​should not be limited to the upper and lower limits or specific examples.

[0049] The invention discloses a single-component ultra-fast hardening polymer grouting material based on self-heating, comprising component A, component B and added water, wherein the mass of component B is 40% to 60% of the mass of component A, and the mass of the added water accounts for 40% to 50% of the mass fraction of component A.

[0050] Component A is calculated by weight percentage as follows: metakaolin 46%~52%, quartz sand 42%~50%, synthetic fiber 0.2%, inorganic retarder 0.1~0.2%, calcium ion activator 3.4%~3.8%, slag 2-6%, nano-reinforcer 1.5‰, aluminum tripolyphosphate reinforcing agent 0.2%, and the sum of the weight percentages of all raw materials is 100%.

[0051] Component B is calculated by weight percentage: water glass 70%~78%, solid sodium hydroxide 7%~15%, quartz sand 5%~15%, retarder powder 0.5~3%, water reducer 0.3%, and the sum of the weight percentages of all raw materials is 100%.

[0052] Specifically, the mesh number of the metakaolin is not less than 1250 meshes, the mesh number of the quartz sand is 40-120 meshes, the modulus of the water glass is 2.1-2.3, and the modulus of the alkaline activator prepared by using water glass and solid sodium hydroxide is 1.4-1.6.

[0053] Furthermore, the water glass is powdered instant sodium silicate with a mesh size of ≥100 meshes.

[0054] Furthermore, the calcium ion activator can be calcium hydroxide, calcium oxide, or nano-calcium carbonate, and the weight percentage is the effective mass of CaO.

[0055] Furthermore, the synthetic fiber is 3mm PVA short fiber, or can be one or more of PVA fiber and PP fiber.

[0056] Furthermore, the nano-enhancer is one or more of carbon nanotubes and nano-silicon dioxide.

[0057] Furthermore, the inorganic retarder in component A is barium chloride, and the retarder powder in component B is sodium hexametaphosphate powder with a purity of 98%.

[0058] Furthermore, the water reducer is one or both of a powdered naphthalene water reducer and a powdered aliphatic water reducer. The preferred solution is to mix the naphthalene water reducer and the aliphatic water reducer in a ratio of 2:1.

[0059] The preparation method and use method thereof in the laboratory include the following steps:

[0060] (1) Based on the preliminary proportion of the single-component geopolymer grouting material, calculate according to the self-heating factor calculation formula. When the self-heating factor is not within the stated range, the geopolymer proportion is corrected according to the correction formula to meet the self-heating requirements and / or the material temperature can be adjusted.

[0061] Keep the self-heating factor T between 2-4.5.

[0062] (2) Mixing metakaolin, quartz sand, calcium ion activator, PVA fiber, barium chloride, slag, and nano-reinforcement agent in the above proportions, stirring evenly, and then adding reinforcing agent aluminum tripolyphosphate to obtain component A;

[0063] (3) Mix water glass, quartz sand, caustic soda, sodium hexametaphosphate, and water reducer in proportion and stir evenly to obtain powder material B;

[0064] (4) Weigh component A and component B in proportion, weigh tap water in proportion, mix component A and component B, add them into a JJ-20 planetary mortar mixer and stir at low speed for 60 seconds, pour tap water into it and continue stirring, stir at low speed for 30 seconds and then stir at high speed for 90 seconds;

[0065] (5) The obtained slurry was poured into a 40 mm × 40 mm × 160 mm mold to prepare a test block for measurement.

[0066] To make the contents of the present invention easier to understand, the technical solutions of the present invention are further described below in conjunction with specific implementation examples, but the present invention is not limited thereto. Each example was prepared according to the above laboratory method.

[0067] The XRF analysis of the metakaolin, water glass, and calcium ion activator (cement clinker is used in this example) used in the embodiment is shown in the following table:

[0068] Table 1 Main components of metakaolin

[0069]

[0070] Table 2 Main components of solid water glass

[0071]

[0072] Example 1

[0073] A single-component ultra-fast hard polymer grouting material based on self-heating

[0074] Component A was prepared by adding 1.5‰ carbon nanotubes to 49% metakaolin, 43.7% quartz sand, 3.8% slaked lime, 3% slag, 0.2% PVA fiber, 0.2% aluminum tripolyphosphate reinforcement, and 0.1% barium chloride (total weight percentage of each raw material, equal to 100%). Component B was prepared by adding 82% solid water glass, 14% solid sodium hydroxide, 0.7% quartz sand, 3% sodium hexametaphosphate, and 0.3% fatty water reducer (total weight percentage of each raw material, equal to 100%). Tap water was weighed to make 40% of component A. Using a JJ-20 mortar mixer, components A and B were slowly stirred for 120 seconds. Tap water was added and continued to slowly stir for 30 seconds, followed by rapid stirring for 90 seconds to form a geopolymer slurry. The slurry was then cast into 40 mm × 40 mm × 160 mm test blocks. The initial setting time was measured to be 9 minutes, and the final setting time was 19 minutes. Cured at room temperature for 0-2 hours, and then at 20°C and 95% humidity for 2 hours to 3 days, the specimen's strength was 20.6 MPa at 40 minutes, 27.5 MPa at 2 hours, and 36.4 MPa at 3 days. Using an infrared temperature gun, the specimen's surface temperature was 72.1°C at 40 minutes, 56.2°C at 2 hours, and 20.9°C at 3 days.

[0075] The calculated parameters are as follows:

[0076] Ambient temperature Hydration heat-generating substances Heat of hydration (KJ / g) Component A (g) Component B (g) Na / Al Si / Al Material temperature T 29 62 1.11 800 442 1.34 3.71 23 3.3

[0077] The response is good when the correction formula based on self-heating is met.

[0078] Example 2

[0079] A single-component ultra-fast hard polymer grouting material based on self-heating

[0080] Component A was prepared by adding 1.5‰ carbon nanotubes to 48% metakaolin, 45.6% quartz sand, 2% slag, 3.9% slaked lime, 0.2% PVA fiber, 0.1% barium chloride, and 0.2% aluminum tripolyphosphate (total weight percentage of each raw material) to form component A. Component B was prepared by adding 78% solid water glass, 12% solid sodium hydroxide, 9.2% quartz sand, 0.3% fatty water reducer, and 0.5% sodium hexametaphosphate (total weight percentage of each raw material) to form component B. Tap water was weighed to provide 40% of component A. Using a JJ-20 mortar mixer, components A and B were slowly stirred for 120 seconds. Tap water was added and slowly stirred for 30 seconds, followed by rapid stirring for 90 seconds to form a geopolymer slurry. The slurry was then cast into 40 mm × 40 mm × 160 mm test blocks. The initial setting time was 10 minutes, and the final setting time was 20 minutes. Cured at room temperature for 0-2 hours, and then at 20°C and 95% humidity for 2 hours to 3 days, the specimen's strength was 16.6 MPa at 40 minutes, 32.5 MPa at 2 hours, and 46.72 MPa at 3 days. Using an infrared temperature gun, the specimen's surface temperature was 74.5°C at 40 minutes, 59.3°C at 2 hours, and 20.2°C at 3 days.

[0081] The calculated parameters are as follows:

[0082] Ambient temperature Hydration heat-generating substances Heat of hydration (KJ / g) Component A (g) Component B (g) Na / Al Si / Al Material temperature T 31 63.36 1.11 800 528 1.43 3.65 25 4.29

[0083] The response is good when the correction formula based on self-heating is met.

[0084] The self-heating single-component ultra-fast hardening geopolymer grouting material of the present invention can achieve the ultra-fast hardening, early hardening and high-strength performance of the single-component geopolymer. A solid raw material formula is adopted, and kaolin, quartz sand, calcium ion activator, fiber, etc. are designed as component A according to the proportion, and solid water glass, caustic soda, retarder, etc. are designed as component B according to the proportion. When in use, it is only necessary to mix material A and material B evenly, add water according to the formula and continue stirring until it is in a fluid state, and then repair roads and buildings. This single-component geopolymer powder will generate obvious hydration reaction heat when used. Laboratory measurements show that the surface temperature of the test piece will reach 60°C, which can produce an effect similar to thermal curing, and promote geopolymerization reaction, so that its strength develops rapidly. Laboratory measurements have shown that this formula can achieve initial setting in 10 minutes, final setting in 20 minutes, a compressive strength greater than 15MPa in 40 minutes, a compressive strength greater than 25MPa in 2 hours, and the strength can increase to 35MPa in 3 days. When studying the relationship between the Si, Al, and Na content of raw materials and the influence of calcium-phase admixtures on the heating temperature of single-component geopolymer powder, a formula was proposed to fit the relationship between the heating factors of single-component self-heating geopolymers and environmental and material factors. Furthermore, a correction method was proposed to ensure that single-component geopolymers meet self-heating requirements. This invention has high application value in the field of road repair.

Claims

1. A single-component ultra-fast hard polymer grouting material based on self-heating, characterized in that: Comprising component A and component B; Component A comprises, by weight percentage, 46% to 52% metakaolin, 40% to 50% quartz sand, 0.2% synthetic fiber, 0.1% to 0.2% inorganic retarder, 3.4% to 4% calcium ion activator, 2-6% slag, and 0.2% aluminum tripolyphosphate reinforcing agent, with the sum of the weight percentages of each raw material being 100%. Component A also contains 1.5‰ nano-reinforcement agent; the calcium ion activator is provided by a calcium ion-containing substance, and the weight percentage is the effective mass of CaO; and the inorganic retarder used is barium chloride. Component B is calculated by weight as follows: water glass 70%-78%, solid sodium hydroxide 7%-15%, quartz sand 5%-15%, retarder powder 0.5-3%, water reducer 0.3%, and the sum of the weight percentages of each raw material is 100%; When using, after mixing component A and component B, add water and stir; wherein, the mass fraction of component B accounts for 40% to 60% of the mass fraction of component A, and the mass of the added water accounts for 40% to 50% of the mass fraction of component A; and the self-heating factor T should be between 2 and 4.5 by comprehensive consideration of environmental factors and material factors; the calculation formula of the self-heating factor T is: ， Among them, the hydration exothermic substance is a substance that can make water boil; Na / Al and Si / Al are the molar ratios of the corresponding elements in Na2O, Al2O3, and SiO2 in caustic soda, water glass, metakaolin, and slag.

2. The self-heating single-component ultra-fast hard geopolymer grouting material according to claim 1, characterized in that: The component B is an alkali activator, wherein the modulus of water glass is 2.1-2.3, and the modulus of the alkali activator prepared by using solid sodium hydroxide and water glass is 1.4-1.

6.

3. The self-heating single-component ultra-fast hard geopolymer grouting material according to claim 1, characterized in that: The mesh number of the metakaolin is not less than 1250 meshes, and the mesh number of the quartz sand is 40-120 meshes.

4. The self-heating single-component ultra-fast hard geopolymer grouting material according to claim 1, characterized in that: The synthetic fibers used are one or more of PVA fibers and PP fibers; the nano-reinforcers used are one or more of carbon nano-tubes and nano-silicon oxides.

5. The self-heating single-component ultra-fast hard geopolymer grouting material according to claim 1, characterized in that: The water glass is powdered instant sodium silicate with a mesh size of ≥100 mesh; the retarder powder is sodium hexametaphosphate powder with a purity of 98%; and the water reducer is one or both of a powdered naphthalene-based water reducer and a powdered aliphatic water reducer.

6. The self-heating single-component ultra-fast hard geopolymer grouting material according to claim 1, characterized in that: When the self-heating factor T does not meet the range requirements, the material ratios should be corrected and / or the environment and material temperatures should be adjusted.

7. The method for using the grouting material according to claim 1, wherein: include: Mix component A and component B in proportion, add water, stir and pour, wait for it to solidify and then maintain.

8. The grouting material according to any one of claims 1 to 6, characterized in that: The water is tap water or sea water.

9. The method according to claim 7, wherein The water is tap water or sea water.

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