Cement-based waterproof grouting material and preparation method and application thereof

Abstract

The present invention discloses a cement-based waterproof grouting material, a preparation method thereof, and an application thereof. The components of the cement-based waterproof grouting material of the present invention include sulfoaluminate cement, silicate cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, a water reducer, a retarder, a waterproofing agent, an emulsifier, and water. The preparation method of the cement-based waterproof grouting material of the present invention is very simple, and the components are mixed evenly in batches. The cement-based waterproof grouting material of the present invention has the advantages of a small number of additives and a small amount of additives, excellent processing performance, excellent waterproof and anti-seepage performance after curing, and high compressive strength and flexural strength after curing. In addition, the preparation process is simple, and no changes are required to existing production equipment and transportation equipment. It is suitable for grouting repair of highway base diseases.

Description

Technical Field

[0001] The present invention relates to the technical field of cement-based composite materials, and in particular to a cement-based waterproof grouting material and a preparation method and application thereof. Background Art

[0002] Highways are public roads approved by transportation authorities for use by vehicles between cities, rural areas, and rural areas. They are essential transportation infrastructure for daily life. However, due to the constraints and influence of various factors, such as road construction materials, external environment, vehicle loads, and construction techniques, highways inevitably experience damage during use.

[0003] In response to non-structural damage to highways, traditional milling and paving reinforcement technologies have disadvantages such as long construction period, high construction cost, and significant impact on normal highway traffic. They have been gradually replaced by grouting reinforcement technology. Grouting reinforcement technology refers to the process of injecting slurry into the pores of the highway base layer in a filling, compacting, and infiltration grouting manner under a certain grouting pressure to expel air and moisture from the damaged location. Once the slurry solidifies, the cracked or loose base structure will be solidified into a solid body, thereby ultimately repairing the highway. Grouting reinforcement technology is a "non-excavation" reinforcement technology with the advantages of low environmental pollution, minimal damage to the original structure of the highway, and minimal impact on normal highway traffic. It has good application prospects. However, existing cement-based grouting materials generally have many problems such as a large number of additives, poor processing performance, lack of waterproofing after curing, and low strength after curing, making it difficult to fully meet actual application requirements.

[0004] Therefore, it is of great significance to develop a cement-based grouting material with a small number of additives and a small amount of additives, excellent processing performance, excellent waterproof and anti-seepage properties after curing, and high compressive strength and flexural strength after curing. Summary of the Invention

[0005] The purpose of the present invention is to provide a cement-based waterproof grouting material and a preparation method and application thereof.

[0006] The technical solution adopted by the present invention is:

[0007] A cement-based waterproof grouting material, comprising the following components in parts by weight:

[0008] Sulphoaluminate cement: 25 to 35 parts;

[0009] Portland cement: 30 to 40 parts;

[0010] Fly ash: 5 to 10 parts;

[0011] Kaolin: 5 to 10 parts;

[0012] Ultrafine silicon dioxide powder: 5 to 10 parts;

[0013] Nano-alumina sol: 1 to 3 parts;

[0014] Water reducing agent: 1 to 2 parts;

[0015] Retarder: 0.1 to 0.3 parts;

[0016] Waterproofing agent: 0.5 to 10 parts;

[0017] Emulsifier: 0.1 to 3 parts;

[0018] Water: 30 to 40 parts.

[0019] The water-cement ratio (the ratio of the total mass of water to sulphoaluminate cement, silicate cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, water reducer and retarder) is crucial. If the water-cement ratio is too large, the waterproofing agent will easily float, resulting in differences in the waterproofing properties of the interior and surface of the cement-based waterproof grouting material after solidification. If the water-cement ratio is too small, it will be detrimental to the dispersion of the waterproofing agent and emulsifier, and it will easily harden in a short time, affecting the processing performance of the cement-based waterproof grouting material.

[0020] Preferably, the particle size of the sulphoaluminate cement is less than 38 μm and the strength grade is 42.5 to 72.5.

[0021] Preferably, the particle size of the Portland cement is less than 38 μm and the strength grade is 32.5 to 52.5.

[0022] Preferably, the particle size of the fly ash is less than 38 μm.

[0023] Preferably, the particle size of the kaolin is less than 38 μm. The particle size of sulphoaluminate cement, Portland cement, fly ash and kaolin is less than 38 μm, which can effectively reduce the initial setting time of the grouting material, increase the initial setting compressive strength, and reduce the final setting compressive strength.

[0024] Preferably, the particle size of the ultrafine silicon dioxide powder is 100 nm to 300 nm.

[0025] Preferably, the particle size of the nano-alumina sol is 1 nm to 300 nm.

[0026] Preferably, the water reducer is at least one of lignin sulfonate water reducer, naphthalene water reducer, melamine water reducer, aminosulfonate water reducer, aliphatic water reducer, and polycarboxylic acid water reducer.

[0027] Preferably, the retarder is at least one of lignin sulfonate, hydroxycarboxylic acid and its salts, polyols and its derivatives, sugars and carbohydrates, phosphates, metaphosphates, borax, and sodium fluorosilicate.

[0028] Preferably, the waterproofing agent is at least one of polyisobutylene, natural latex, and silicone oil.

[0029] Preferably, the number average molecular weight of the polyisobutylene is 350-3500.

[0030] Preferably, the number average molecular weight of the natural rubber latex is 30,000 to 300,000.

[0031] Preferably, the number average molecular weight of the silicone oil is 1000 to 20000. The waterproofing agent is a non-polar polymer with excellent hydrophobicity, which can make the grouting material have excellent waterproof and anti-seepage properties inside and on the surface after curing. In addition, the non-polar polymer does not react with silicates and does not affect the hydration reaction process of the cement itself, so that the grouting material can maintain good processing properties and maintain good strength and toughness after curing.

[0032] Preferably, the emulsifier is at least one of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, and polyoxyethylene ether surfactants.

[0033] Preferably, the polyoxyethylene ether surfactant is at least one of fatty alcohol polyoxyethylene ether (AEO), alkylphenol polyoxyethylene ether (APEO), fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and polyether polyol. The polar end of the emulsifier hydrogen bonds with the surface of the ultrafine silica powder, and the non-polar end bonds with the waterproofing agent, thereby improving the dispersibility of the waterproofing agent in the grouting material and also acting as a water reducer and stabilizer. After the cement hydration reaction is completed, the non-polar waterproofing agent, with the help of the emulsifier, acts on the capillary walls of the internal pores of the cement, turning the originally hydrophilic capillary walls into hydrophobic ones, making it difficult for water to enter the cement pores, thereby enhancing the waterproof and anti-seepage properties of the grouting material after curing. In addition, the unique flexibility of the polymer also gives the grouting material good toughness and flexural resistance after curing.

[0034] A method for preparing the cement-based waterproof grouting material as described above comprises the following steps:

[0035] 1) Sulphoaluminate cement, Portland cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, water reducer and retarder are mixed to form mixture A, and waterproofing agent, emulsifier and water are mixed and stirred and dispersed at a stirring speed of 200 rpm to 400 rpm for 30 seconds to 120 seconds to form mixture B;

[0036] 2) Mixing mixture A and mixture B, and then stirring and dispersing them at a stirring speed of 400 rpm to 600 rpm for 120 s to 240 s to obtain a cement-based waterproof grouting material.

[0037] In step 1), stirring and dispersing is performed, and the amphiphilicity of the emulsifier can be used to wrap the non-polar waterproofing agent in the emulsifier droplets, so that the formed tiny droplets are evenly dispersed in the aqueous solution; the stirring and dispersing time in step 2) is very critical. If the stirring time is too short, the waterproofing agent is unevenly dispersed, resulting in an unsatisfactory waterproofing effect. If the stirring time is too long, the cement hydration gel process will be mechanically destroyed, making it difficult to ensure the adhesion and compressive strength of the grouting material.

[0038] The invention discloses an application of the cement-based waterproof grouting material as described above in the repair of highway base.

[0039] The beneficial effects of the present invention are: the cement-based waterproof grouting material of the present invention has the advantages of few types and amounts of additives, excellent processing performance, excellent waterproof and anti-seepage performance after curing, and high compressive strength and flexural strength after curing. In addition, its preparation process is simple and does not require changes to existing production equipment and transportation equipment. It is suitable for grouting repair of highway base diseases.

[0040] Specifically:

[0041] 1) The cement-based waterproof grouting material of the present invention does not affect the hydration reaction of the cement itself (for example, initial setting time, final setting time, etc.) and has excellent processing performance;

[0042] 2) The cement-based waterproof grouting material of the present invention has excellent waterproof and anti-seepage properties both inside and on the surface after curing;

[0043] 3) The cement-based waterproof grouting material of the present invention has the characteristics of high initial setting strength and low final setting strength;

[0044] 4) The preparation method of the cement-based waterproof grouting material of the present invention is very simple, has low equipment requirements (no need to modify existing production equipment and transportation equipment), and the types and amounts of additives are small, which is conducive to actual production and construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a diagram showing the internal structure of the capillaries of the cement-based waterproof grouting material of the present invention and the traditional cement-based grouting material after curing.

[0046] Figure 2 This is a diagram showing the waterproofing effect test results of the specimen made of the cement-based waterproof grouting material of Example 1.

[0047] Figure 3 Schematic diagram of the structure of the capillary water absorption test device. DETAILED DESCRIPTION

[0048] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0049] Example 1:

[0050] A cement-based waterproof grouting material, the composition of which is shown in the following table:

[0051] Table 1 Composition of a cement-based waterproof grouting material

[0052]

[0053] The preparation method of the above-mentioned cement-based waterproof grouting material comprises the following steps:

[0054] 1) Sulphoaluminate cement, Portland cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, naphthalene-based water reducer, and borax were mixed to form a mixture A, and polyisobutylene, polyvinyl alcohol, and water were mixed and stirred at 200 rpm for 60 seconds to form a mixture B;

[0055] 2) Mixture A and mixture B were mixed and stirred for 240 seconds at a stirring speed of 400 rpm to obtain a cement-based waterproof grouting material.

[0056] Example 2:

[0057] A cement-based waterproof grouting material, the composition of which is shown in the following table:

[0058] Table 2 Composition of a cement-based waterproof grouting material

[0059]

[0060] The preparation method of the above-mentioned cement-based waterproof grouting material comprises the following steps:

[0061] 1) Sulphoaluminate cement, Portland cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, melamine water reducer, and sodium pyrophosphate were mixed to form mixture A, and natural rubber latex, polyacrylamide, and water were mixed and stirred at 200 rpm for 60 seconds to form mixture B;

[0062] 2) Mixture A and mixture B were mixed and stirred for 240 seconds at a stirring speed of 400 rpm to obtain a cement-based waterproof grouting material.

[0063] Example 3:

[0064] A cement-based waterproof grouting material, the composition of which is shown in the following table:

[0065] Table 3 Composition of a cement-based waterproof grouting material

[0066]

[0067] The preparation method of the above-mentioned cement-based waterproof grouting material comprises the following steps:

[0068] 1) Sulphoaluminate cement, Portland cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, polycarboxylate water reducer, and sodium gluconate were mixed to form mixture A, and silicone oil, polyacrylic acid, and water were mixed and stirred and dispersed at a stirring speed of 200 rpm for 60 seconds to form mixture B;

[0069] 2) Mixture A and mixture B were mixed and stirred for 240 seconds at a stirring speed of 400 rpm to obtain a cement-based waterproof grouting material.

[0070] Comparative Example 1:

[0071] A cement-based grouting material is identical to Example 1 except that polyisobutylene and polyvinyl alcohol are not added.

[0072] Comparative Example 2:

[0073] A cement-based grouting material is identical to Example 1 except that no polyvinyl alcohol is added.

[0074] Comparative Example 3:

[0075] A cement-based grouting material is identical to Example 1 except that the amount of polyisobutylene added is adjusted to 30 parts by mass.

[0076] Performance testing:

[0077] 1) The internal structure of the capillary of the cement-based waterproof grouting material of the present invention and the traditional cement-based grouting material after curing is as shown in the figure Figure 1 (a is a traditional cement-based grouting material, b is the cement-based waterproof grouting material of the present invention).

[0078] Depend on Figure 1 It can be seen that after the traditional cement-based grouting material is cured, the inner wall of the capillary is covered with hydroxyl groups, is hydrophilic, and does not have waterproof and anti-seepage properties. However, after the cement-based waterproof grouting material of the present invention is cured, the inner wall of the capillary is hydrophobic (the polar end of the emulsifier is combined with the hydroxyl groups on the inner wall of the capillary in the form of a hydrogen bond, and the non-polar end is combined with the waterproofing agent, thereby converting the inner wall of the capillary from hydrophilic to hydrophobic), and has excellent waterproof and anti-seepage properties.

[0079] 2) The waterproof effect test results of the test piece made of the cement-based waterproof grouting material of Example 1 are as follows Figure 2 (a is the waterproof effect test result diagram of the specimen surface, b is the waterproof effect test result diagram of the internal section of the specimen).

[0080] Depend on Figure 2 It can be seen that the surface and interior of the test piece made of the cement-based waterproof grouting material of Example 1 show good waterproof effect, and water drops thereon form beads without scattering or seeping.

[0081] In addition, the test found that the surface and interior of the test pieces made of the cement-based waterproof grouting materials of Example 2 and Example 3 also had good waterproof effects.

[0082] 3) The capillary water absorption, waterproofing effect, initial setting / final setting time and compressive strength test results of the cement-based waterproof grouting materials of Examples 1 to 3 and the cement-based grouting materials of Comparative Examples 1 to 3 are shown in Tables 4 and 5:

[0083] Table 4 Capillary water absorption test results (%)

[0084]

[0085]

[0086] Note:

[0087] Capillary water absorption: The grouting material sample is injected into a mold (square, size of 15cm×15cm×15cm) for molding. The mold is removed after 24 hours, and then placed in a standard curing room for 3 days, and then cured at room temperature for 4 days. Then, it is cut into specimens with a size of 15cm×15cm×7.5cm using a cutting machine. Then, it is placed in an oven and baked at 105℃ for 2 hours, and then baked at 30℃ for 1 hour. Then, the sample weight G1 is obtained by weighing. Then, epoxy resin is applied to the side of the specimen (be careful not to apply it to the bottom surface), and then the specimen is placed on a support bracket so that the inner surface (cut surface) of the specimen is in contact with water, and the water surface is no more than 5mm higher than the specimen (the structural diagram of the capillary water absorption test device is shown in the figure). Figure 3 The sample was taken out at regular intervals, and excess water on the surface in contact with water was wiped off with a damp cloth. The sample was then weighed to obtain the sample weight G2. Each sampling and weighing process was completed within 30 seconds. The capillary water absorption rate (W) was calculated according to the following formula: W (%) = (G2-G1) / G1×100%, where G1 is the dry weight of the sample (in g), and G2 is the wet weight of the sample after water absorption (in g). Three parallel groups were set for each sample, and the average value was taken.

[0088] It can be seen from Table 4 that the capillary water absorption of the cement-based waterproof grouting materials of Examples 1 to 3 is extremely low, and has an excellent waterproof effect, while the capillary water absorption of the cement-based grouting material of Comparative Example 1 (without adding waterproofing agent and emulsifier) ​​is very high and has no waterproof effect. The capillary water absorption of the cement-based grouting material of Comparative Example 2 (with added waterproofing agent, but no emulsifier; the waterproofing agent is a non-polar polymer, which cannot act on the inner wall of the capillary after the cement-based grouting material is cured without the help of an emulsifier, and thus cannot achieve a waterproof effect) is slightly lower than that of the cement-based grouting material of Comparative Example 1, and the waterproof effect is not significantly improved, failing to meet the requirements. Although the capillary water absorption of the cement-based grouting material of Comparative Example 3 (however much emulsifier is added) is lower than that of the cement-based grouting materials of Comparative Examples 1 and 2, the waterproof effect is still not ideal.

[0089] Table 5 Waterproof effect, initial setting / final setting time and compressive strength test results

[0090]

[0091]

[0092] Note:

[0093] Waterproof effect: Evaluated based on capillary water absorption test results.

[0094] Initial setting time and final setting time: Add water of standard consistency to the grouting material sample to make a pure slurry test mold. From the time of adding water, the time when the test needle of the standard Vicat instrument sinks into the pure slurry 0.5mm to 1.0mm from the bottom plate is the initial setting time, and the time when the test needle sinks into the pure slurry no more than 1.0mm is the final setting time.

[0095] Compressive strength: Tested in accordance with "JTG / T F50-2011 Technical Specifications for Highway Bridge and Culvert Construction".

[0096] It can be seen from Table 5 that the cement-based waterproof grouting materials of Examples 1 to 3 have excellent waterproof effects, and the initial setting time and final setting time both meet the use requirements, and the compressive strengths of 3h and 1 day also meet the use requirements. The cement-based grouting material of Comparative Example 1 (without adding waterproofing agent and emulsifier) ​​has no waterproof effect, and the initial setting time and final setting time both do not meet the use requirements. The sample has compressive strength on the third day, which does not meet the use requirements at all. The cement-based grouting material of Comparative Example 2 (with waterproofing agent added, no emulsifier added) and the cement-based grouting material of Comparative Example 3 (how much emulsifier is added) have poor waterproof effects, longer initial setting time and final setting time, and significantly lower compressive strengths of 3h and 1 day, which do not meet the use requirements at all.

[0097] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A cement-based waterproof grouting material, characterized in that: The composition comprises the following components in parts by weight: Sulphoaluminate cement: 25 to 35 parts; Portland cement: 30 to 40 parts; Fly ash: 5 to 10 parts; Kaolin: 5 to 10 parts; Ultrafine silicon dioxide powder: 5 to 10 parts; Nano-alumina sol: 1 to 3 parts; Water reducing agent: 1 to 2 parts; Retarder: 0.1 to 0.3 parts; Waterproofing agent: 0.5 to 10 parts; Emulsifier: 0.1 to 3 parts; Water: 30-40 parts; The particle size of the sulphoaluminate cement is less than 38 μm and the strength grade is 42.5 to 72.5; The particle size of the Portland cement is less than 38 μm and the strength grade is 32.5 to 52.5; The particle size of the fly ash is less than 38 μm; The particle size of the kaolin is less than 38 μm; The waterproofing agent is at least one of polyisobutylene, natural latex, and silicone oil; The emulsifier is at least one of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, and polyoxyethylene ether surfactants.

2. The cement-based waterproof grouting material according to claim 1, characterized in that: The particle size of the ultrafine silicon dioxide powder is 100nm to 300nm.

3. The cement-based waterproof grouting material according to claim 1, characterized in that: The particle size of the nano-alumina sol is 1 nm to 300 nm.

4. The cement-based waterproof grouting material according to claim 1, characterized in that: The water reducer is at least one of lignin sulfonate water reducer, naphthalene water reducer, melamine water reducer, aminosulfonate water reducer, aliphatic water reducer, and polycarboxylic acid water reducer; the retarder is at least one of lignin sulfonate, hydroxycarboxylic acid and its salts, polyols and their derivatives, sugars and carbohydrates, phosphates, metaphosphates, borax, and sodium fluorosilicate.

5. A method for preparing a cement-based waterproof grouting material according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) Sulphoaluminate cement, Portland cement, fly ash, kaolin, ultrafine silica powder, nano-alumina sol, water reducer and retarder are mixed to form mixture A, and waterproofing agent, emulsifier and water are mixed and stirred and dispersed at a stirring speed of 200 rpm to 400 rpm for 30 seconds to 120 seconds to form mixture B; 2) Mixing mixture A and mixture B, and then stirring and dispersing them at a stirring speed of 400 rpm to 600 rpm for 120 s to 240 s to obtain a cement-based waterproof grouting material.

6. Use of the cement-based waterproof grouting material according to any one of claims 1 to 4 in repairing a highway base.

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