High-impermeability adjustable-setting type inorganic waterproof plugging material and preparation method thereof

Abstract

The invention relates to the field of building waterproof materials, in particular to a high-impermeability adjustable-setting type inorganic waterproof plugging material and a preparation method thereof. The waterproof plugging material is prepared from the following raw materials in parts by weight: 45 to 65 parts of sulphoaluminate cement, 5 to 20 parts of PO.525 cement, 5 to 8 parts of mineral powder, 8 to 10 parts of silica fume, 1 to 2 parts of heavy magnesium oxide, 1 to 2 parts of modified nano calcium carbonate, 1 to 2 parts of dispersible rubber powder, 0.05 to 0.1 part of a water reducing agent, 0.05 to 0.1 part of a de-foaming agent and 0.07 to 0.15 part of hydroxypropyl methyl cellulose. The plugging material disclosed by the invention has excellent impermeability, bonding strength and toughness and adjustable setting time.

Description

Technical Field

[0001] The present application relates to the field of building waterproof materials, and in particular to a high anti-seepage adjustable setting inorganic waterproof plugging material and a preparation method thereof. Background Art

[0002] Building leakage has long been a difficult problem plaguing the construction industry. It not only affects the normal use of buildings, but also shortens their service life and even endangers building safety. Traditional waterproof plugging materials, such as organic materials like asphalt and polyurethane, although having certain waterproof effects, have problems such as easy aging, short lifespan, and environmental pollution. Inorganic waterproof plugging materials, such as cement-based penetrating crystalline waterproof materials, although having advantages such as good durability and environmental protection, also have defects such as insufficient anti-seepage performance, short setting time, low bond strength, and poor toughness.

[0003] Traditional inorganic waterproof plugging materials have the following problems: insufficient anti-seepage performance, making it difficult to meet the requirements of modern buildings for high anti-seepage performance; low bond strength, prone to problems such as peeling and cracking, affecting the waterproof effect and making it difficult to ensure long-term waterproof reliability; poor toughness, traditional inorganic waterproof plugging materials are brittle, with poor crack resistance, difficult to adapt to the deformation of the substrate, prone to secondary leakage, and difficult to meet the waterproof requirements under complex stress environments.

[0004] In order to overcome the limitations of traditional inorganic waterproof plugging materials, the development of high-performance and environmentally friendly high anti-seepage retardant inorganic waterproof plugging materials has become an industry trend. Summary of the Invention

[0005] In order to make the plugging material have excellent anti-seepage performance, bond strength and toughness as well as adjustable setting time, the present application provides a high anti-seepage adjustable setting inorganic waterproof plugging material and a preparation method thereof.

[0006] On the one hand, the present application provides a high anti-seepage adjustable setting inorganic waterproof plugging material, which includes the following raw materials in parts by weight: 45 - 65 parts of sulfoaluminate cement, 5 - 20 parts of PO·525 cement, 5 - 8 parts of mineral powder, 8 - 10 parts of silica fume, 1 - 2 parts of heavy magnesium oxide, 1 - 2 parts of modified nano calcium carbonate, 1 - 2 parts of redispersible powder, 0.05 - 0.1 part of water reducing agent, 0.05 - 0.1 part of defoaming agent, and 0.07 - 0.15 part of hydroxypropyl methyl cellulose.

[0007] This application selects sulfoaluminate cement and PO·525 cement as the main components. By adjusting the ratio of the two, the setting time of the material can be adjusted, and the setting can be extended, thereby improving the construction workability and enabling it to meet the construction requirements of large areas or complex structures. The addition of redispersible polymer powder can improve the flexibility, crack resistance and bonding strength of the material, enabling it to adapt to the deformation of the substrate, effectively preventing secondary leakage, and at the same time preventing peeling and cracking, ensuring the integrity and long-term reliability of the waterproof layer. Hydroxypropyl methyl cellulose (HPMC) has a water retention effect. The water retention effect of cellulose ether can extend the working time of the plugging material, improve the strength and durability of the material after hardening, and at the same time improve the adhesion of the material to the surface. The water reducing agent can reduce the water-cement ratio and improve the strength and stability of the material. The defoaming agent can inhibit or eliminate the foam during the mixing process of the material with water, and improve the strength and density of the material.

[0008] Heavy magnesium oxide can reduce the pore structure of the inorganic waterproof plugging material and improve its density and durability. Silica fume can well fill the voids, making the plugging material more dense. In addition, it also combines with free Ca(OH) 2 to form a stable calcium silicate hydrate 2CaO·SiO 2 ·H 2 O. The gel strength of this hydrate is higher than that of Ca(OH) 2 crystals, improving the compressive strength of the material. The inventor uses heavy magnesium oxide and silica fume together, which can reduce the voids while silica fume realizes the dense filling of the voids. Modified nano calcium carbonate can act as a crystal nucleus during the curing process of the inorganic waterproof plugging material, promoting the crystallization process of cementitious materials such as cement, making the crystal grains finer. The refined crystal grain structure is more uniform and compact, reducing the pores and defects between large-sized crystal grains. Through the action of the above three components, the pore structure of the material is optimized, the density is increased, and the impermeability performance is enhanced, enabling it to effectively resist the penetration of high water pressure and complex cracks.

[0009] Preferably, the mineral powder is S95 mineral powder, with a mesh number of 600 and a density of 2.8 g / cm 3 .

[0010] Preferably, the water reducing agent is a polycarboxylate water reducing agent; the defoaming agent is a modified polyether defoaming agent.

[0011] Preferably, the hydroxypropyl methyl cellulose is hydroxypropyl methyl cellulose with a viscosity of 4000, and the density is 0.45 g / cm 3 .

[0012] Preferably, the silica fume is quaternary ammonium salt chitosan modified silica fume; the heavy magnesium oxide is sodium alginate modified magnesium oxide.

[0013] Silica fume and magnesium oxide are modified by a conventional organic modification process. Generally, silica fume and magnesium oxide modified by an organic modifier can further improve dispersion and mixing performance. Quaternary ammonium salt chitosan and sodium alginate are also commonly used as modifiers to improve the dispersion of particles. The inventors found that selecting quaternary ammonium salt chitosan modified silica fume and sodium alginate modified magnesium oxide to prepare a plugging material can achieve unexpectedly better anti-seepage effect. This may be due to the electrostatic assembly between quaternary ammonium salt chitosan and sodium alginate, which can promote better arrangement and connection of silica fume and magnesium oxide in the system. Under the action of heavy magnesium oxide, while the pore structure is reduced, the silica fume distributed around can be filled quickly based on the above-mentioned action, so that the two cooperate with each other during the curing process to achieve a better filling effect, and the plugging material is more dense.

[0014] Preferably, the modified nano calcium carbonate is nano calcium carbonate modified by a silane coupling agent. More preferably, the silane coupling agent is an amino silane coupling agent. The silane coupling agent can improve the dispersion of nano calcium carbonate and prevent particle aggregation. And when the inventors selected a silane coupling agent, they found that when an amino silane coupling agent was selected, the anti-seepage property of the obtained plugging material was better. This may be because during the self-assembly process of quaternary ammonium salt chitosan modified silica fume and sodium alginate modified magnesium oxide, the amino silane coupling agent participates in the self-assembly process based on the hydrogen bond action and the action of amino and carboxyl groups. With the help of the surface-grafted amino group, the dispersion of nano calcium carbonate is further improved, so as to give full play to the optimization crystallization effect, making the crystal grains formed during the crystallization process of cement more uniform and compact, and improving the anti-seepage property of the plugging material.

[0015] Preferably, the silica fume is SiO 2 fully encrypted silica fume with a content greater than 94%, a bulk density of 270 kg / m 3 , and a pH value of 7.

[0016] On the other hand, the present application provides a preparation method of a high anti-seepage adjustable setting inorganic waterproof plugging material. The method includes the following steps: weighing each component according to the formula ratio, adding sulfoaluminate cement and PO·525 cement into a reaction kettle, then adding silica fume, mineral powder, modified nano calcium carbonate, and finally adding a water reducing agent, redispersible rubber powder, defoaming agent, hydroxypropyl methyl cellulose, and heavy magnesium oxide in sequence, stirring at 200 r / min for more than half an hour, and then filling into bags and sealing.

[0017] When the waterproof plugging material of the present application is used, 12% - 14% of water is added, and after stirring evenly, it can be constructed.

[0018] In summary, the present application has the following beneficial technical effects: 1. This application optimizes the pore structure of the material by adding silica fume, heavy magnesium oxide, and modified nano-calcium carbonate, improves the density, and enhances the impermeability performance, enabling it to effectively resist the penetration of high water pressure and complex cracks; by adjusting the ratio of sulfoaluminate cement and PO·525 cement, the setting time of the material is extended, the construction operability is improved, and it can adapt to the construction requirements of large areas or complex structures; by adding redispersible polymer powder, the flexibility, crack resistance, and bonding strength of the material are improved, enabling it to adapt to the deformation of the substrate, effectively preventing secondary leakage, and at the same time preventing peeling and cracking, ensuring the integrity and long-term reliability of the waterproof layer.

[0019] 2. This application selects quaternary ammonium salt chitosan-modified silica fume and sodium alginate-modified magnesium oxide to prepare a plugging material. The electrostatic assembly between quaternary ammonium salt chitosan and sodium alginate can promote better arrangement of silica fume and magnesium oxide in the system. While heavy magnesium oxide shrinks the pore structure, the silica fume distributed around it can be filled more quickly, so that the two cooperate to achieve a better filling effect during the curing process, and the plugging material is more dense.

[0020] 3. This application modifies nano-calcium carbonate with an amino-silane coupling agent. The silane coupling agent can improve the dispersion of nano-calcium carbonate and prevent particle aggregation. Based on the interaction between the amino group and quaternary ammonium salt chitosan-modified silica fume and sodium alginate-modified magnesium oxide, the dispersion of nano-calcium carbonate is further improved, so that the crystal grains formed during the crystallization process of cement are more uniform and compact, improving the impermeability.

[0021] 4. This application is of great significance for improving the quality of construction projects, extending the service life of buildings, saving resources, and protecting the environment. With the continuous progress of materials science and technology, high impermeability and adjustable setting inorganic waterproof plugging materials will have a broader development prospect, providing a more effective solution to solve the problem of building leakage. Detailed implementation mode

[0022] The following further details this application through examples.

[0023] The sulfoaluminate cement is purchased from Anjian Hongye; the PO·525 cement is purchased from Xinjianan Building Materials Co., Ltd.; the silica fume is fully encrypted silica fume with a SiO 2 content greater than 94%, bulk density 270 kg / m 3 , pH value 7; the mineral powder is S95 mineral powder, mesh number 600 mesh, density 2.8 g / cm 3 ; the particle size of nano-calcium carbonate is 100 nm; the redispersible polymer powder is purchased from Hebei Chaoyan New Material Technology Co., Ltd., the heavy magnesium oxide is purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd., and the active ingredient is 99.9%; the water reducing agent is LG-2, purchased from Boruida Building Materials; the defoaming agent is Xingbang A406; the HPMC viscosity is 4000, density 0.45 g / cm3 All other components are of conventional grades in the art or obtained through conventional processes. Examples

[0024] Example 1: Weigh each component according to the formulation ratio in Table 1. Then, first add sulfoaluminate cement and PO·525 cement into the reaction kettle, followed by adding silica fume, mineral powder, and modified nano calcium carbonate. Finally, add water reducing agent, redispersible polymer powder, defoamer, HPMC, and heavy magnesium oxide in sequence. Stir thoroughly in the reaction kettle for 1 h at a rotation speed of 200 r / min, and then seal it in a bag.

[0025] The modified nano calcium carbonate is methyltrimethoxysilane modified nano calcium carbonate; Preparation method: Prepare an 800 mL ethanol / water mixed solution (ethanol / water volume ratio 1 / 1), add methyltrimethoxysilane to the above mixed solution and stir for 30 min, and the addition amount of silane is 2.5 wt% of the mixed solution; Add 15 g of nano calcium carbonate to the mixed solution, reflux and stir at 60 °C for 2 h, and separate, wash, and dry to obtain the modified nano calcium carbonate.

[0026] Examples 2 - 4: The differences between Examples 2 - 4 and Example 1 are only in the component ratios, and the ratios are shown in Table 1.

[0027] Table 1 Referring to GB 23440 - 2009 "Inorganic Waterproof Plugging Materials", prepare specimens of the plugging materials prepared according to the formulations and methods of Examples 1 - 4, and test the initial setting, final setting, 1 h, 3 d flexural and compressive strengths, 7 d bond strength, and 7 d impermeability pressure of the inorganic waterproof plugging materials. At the same time, supplement the test of the 28 d flexural and compressive strengths. The specific tests are shown in Table 2.

[0028] Table 2 It can be seen from Table 2 that the impermeable plugging materials prepared in this application have excellent compressive, flexural, and impermeability properties, high bond strength, and all properties are higher than the national standards. In addition, by adjusting the ratio of sulfoaluminate cement and PO·525 cement, the setting time can be adjusted to achieve better processability.

[0029] Examples 5 - 7 The differences between Example 5 and Example 1 are only that: the silica fume is quaternary ammonium salt chitosan modified silica fume, and the heavy magnesium oxide is sodium alginate modified magnesium oxide.

[0030] The preparation method of quaternary ammonium salt chitosan modified silica fume is: Prepare an 800 mL ethanol / water mixed solution (ethanol / water volume ratio 1 / 1). Add the silane coupling agent KH560 to the above mixed solution and stir for 30 min. The addition amount of KH560 is 2.5 wt% of the mixed solution. Add 25 g of silica fume to the mixed solution, and reflux and stir at 55 °C for 2 h. Separate, wash, and dry to obtain modified silica fume. Prepare an aqueous solution with a mass percentage of 5% from 10 g of quaternary ammonium salt chitosan. Add the modified silica fume and NaOH (the addition amount is 5% of the mass of the quaternary ammonium salt chitosan aqueous solution), and react at 105 °C for 4.5 h. Distill to obtain quaternary ammonium salt chitosan modified silica fume.

[0031] The preparation method of sodium alginate modified magnesium oxide is as follows: Prepare an 800 mL ethanol / water mixed solution (ethanol / water volume ratio 1 / 1). Add the silane coupling agent KH560 to the above mixed solution and stir for 30 min. The addition amount of KH560 is 2.5 wt% of the mixed solution. Add 20 g of magnesium oxide to the mixed solution, and reflux and stir at 60 °C for 2 h. Separate, wash, and dry to obtain modified magnesium oxide. Prepare an aqueous solution with a mass percentage of 5% from 6 g of sodium alginate. Add the modified magnesium oxide and NaOH (the addition amount is 7% of the mass of the sodium alginate aqueous solution), and react at 105 °C for 4 h. Distill to obtain sodium alginate modified magnesium oxide.

[0032] The difference between Example 6 and Example 5 is only that: the modified nano calcium carbonate is epoxy group silane KH560 modified nano calcium carbonate.

[0033] The difference between Example 7 and Example 5 is only that: the modified nano calcium carbonate is amino silane KH550 modified nano calcium carbonate.

[0034] Comparative Example 1-2 The difference between Comparative Example 1 and Example 5 is only that: an equal amount of quaternary ammonium salt chitosan modified silica fume is used to replace sodium alginate modified magnesium oxide.

[0035] The difference between Comparative Example 2 and Example 5 is only that: an equal amount of sodium alginate modified magnesium oxide is used to replace quaternary ammonium salt chitosan modified silica fume.

[0036] Referring to GB 23440-2009 "Inorganic Waterproof Plugging Materials", prepare specimens from the plugging materials prepared by the methods of Examples 5-7 and Comparative Examples 1-2, and test the initial setting, final setting, 1 h, 3 d flexural and compressive strengths, 7 d bond strength, and 7 d specimen impermeability pressure of the inorganic waterproof plugging materials. At the same time, supplement the test of the 28 d flexural and compressive strengths. The specific tests are shown in Table 3.

[0037] Table 3 Referring to Table 3, it can be seen from Examples 1 and 5 that the plugging material prepared by modifying silica fume with quaternary ammonium salt chitosan and modifying magnesium oxide with sodium alginate has improved in terms of bond strength and impermeability pressure compared with the unmodified one. And it can be seen from Examples 5 and Comparative Examples 1-2 that, compared with adding quaternary ammonium salt chitosan-modified silica fume or sodium alginate-modified magnesium oxide alone, adding the above components together achieves unexpectedly better impermeability. This may be because the electrostatic assembly between quaternary ammonium salt chitosan and sodium alginate can promote better arrangement of silica fume and magnesium oxide in the system. While the heavy magnesium oxide shrinks the pore structure, the silica fume distributed around it based on the electrostatic assembly can be filled more quickly, so that the two cooperate to achieve a better filling effect during the curing process, and the plugging material is denser. It can be seen from Examples 5-7 that, compared with other silane coupling agents, modifying nano calcium carbonate with amino silane coupling agent achieves better impermeability and compressive strength. This may be because during the self-assembly of quaternary ammonium salt chitosan-modified silica fume and sodium alginate-modified magnesium oxide, due to hydrogen bond interaction, the amino and carboxyl groups participate in the self-assembly process, and with the help of the amino group, the dispersion of nano calcium carbonate is further improved, so that the crystal grains formed during the crystallization process of cement are more uniform and compact, improving impermeability.

[0038] The present application solves the problems of traditional waterproof plugging materials such as insufficient impermeability performance, uncontrollable setting time, and poor durability, extends the service life of buildings, and can adapt to different construction environments and requirements, improving construction efficiency and quality. At the same time, it can also reduce the later maintenance cost, thereby reducing the overall project cost.

[0039] This specific embodiment is only an explanation of the present application and is not a limitation thereof. Those skilled in the art can make non-creative modifications to this embodiment as needed after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high-impermeability adjustable-coagulation inorganic waterproof plugging material, characterized in that: The invention comprises the following raw materials in parts by weight: 45-65 parts of sulphoaluminate cement, 5-20 parts of PO·525 cement, 5-8 parts of mineral powder, 8-10 parts of silica fume, 1-2 parts of heavy magnesium oxide, 1-2 parts of modified nano calcium carbonate, 1-2 parts of dispersible rubber powder, 0.05-0.1 parts of water reducing agent, 0.05-0.1 parts of defoaming agent and 0.07-0.15 parts of hydroxypropyl methylcellulose.

2. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 1 is characterized in that: The mineral powder is S95 mineral powder, with a mesh size of 600 and a density of 2.8 g / cm³.

3. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 1 is characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent; and the defoaming agent is a modified polyether defoaming agent.

4. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 1 is characterized in that: The hydroxypropyl methylcellulose is hydroxypropyl methylcellulose with a viscosity of 4000 and a density of 0.45 g / cm 3 .

5. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 1 is characterized in that: The silica fume is quaternary ammonium salt chitosan modified silica fume; the heavy magnesium oxide is sodium alginate modified magnesium oxide.

6. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 5 is characterized in that: The modified nano calcium carbonate is nano calcium carbonate modified by a silane coupling agent.

7. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 6 is characterized in that: The silane coupling agent is an aminosilane coupling agent.

8. The high-impermeability adjustable-setting inorganic waterproof plugging material according to claim 1 is characterized in that: The silica fume is fully encrypted silica fume with a SiO2 content greater than 94% and a bulk density of 270 kg / m 3 , pH value is 7.

9. A method for preparing the high-impermeability adjustable-setting inorganic waterproof plugging material according to any one of claims 1 to 8, characterized in that: Weigh each component according to the formula ratio, add sulphoaluminate cement and PO·525 cement into the reactor, then add silica fume, mineral powder, modified nano calcium carbonate, and finally add water reducer, dispersible rubber powder, defoamer, hydroxypropyl methylcellulose, and heavy magnesium oxide in sequence, stir at 200r / min for more than half an hour, and then put into a bag and seal it.

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