Composite grouting material for metro ballast bed leakage treatment and preparation method of composite grouting material

Abstract

The invention discloses a composite grouting material for metro ballast bed leakage treatment and a preparation method thereof, and relates to the technical field of grouting materials. The grouting material comprises a component A and a component B. The component A comprises 200-280 parts by weight of blast furnace slag powder, 100-200 parts by weight of steel slag powder, 300-500 parts by weight of water, 30-50 parts by weight of a flexibilizer, 20-60 parts by weight of a coagulant, 5-10 parts by weight of a dispersant, 0.5-2 parts by weight of a flocculant and 30-50 parts by weight of a shrinkage inhibitor. And the component B comprises 50-100 parts by weight of fly ash, 30-50 parts by weight of limestone powder and 240-350 parts by weight of modified water glass. The composite cementing material system is adopted, underwater non-dispersive grouting is achieved, early strength development is fast, self-constriction is small, material toughness and anti-fatigue characteristics are remarkably improved, and the composite cementing material is suitable for being used as a subway track bed grouting material.

Description

Technical Field

[0001] The invention relates to the technical field of grouting materials, and specifically provides a subway roadbed leakage plugging grouting material. Background Art

[0002] In recent years, my country's subway construction has developed vigorously, but with it comes the problem of water leakage in shield tunnels. Water leakage is the most common disease in tunnels during operation. Water leakage will cause uneven settlement of the tunnel, which will in turn aggravate the occurrence of water leakage. If it is not intervened, it will form a vicious circle and endanger the structure and operation safety of the shield tunnel. The treatment of water leakage in the tunnel section roadbed has always been a common problem in the industry because of its hidden structure and direct impact on the roadbed track driving safety.

[0003] At present, the grouting materials used in tunnel grouting plugging technology mainly include traditional cement slurry, cement-water glass two-liquid grouting, and chemical grouting such as epoxy resin, polyurethane, and acrylate.

[0004] The invention patent with application number CN202110196979.4 discloses a cement-based grouting material modifier, a cement-based grouting material containing the modifier, and a preparation method of the cement-based grouting material. The modifier includes: 50-100 parts by weight of a first modifying agent, 400-500 parts by weight of a second modifying agent, 100-200 parts by weight of an initiator, 200-300 parts by weight of a promoter, and optionally 50-100 parts by weight of a cross-linking agent: the first modifying agent is resin powder and / or latex powder, and the second modifying agent is microsilica powder and / or fly ash.

[0005] The invention patent with application number CN201510659375.3 discloses a double-liquid grouting material with good durability and no environmental pollution. It uses a mixture of amorphous calcium aluminate, gypsum and water - mud A, which has a fast dissolution rate and can react quickly with silicate cement, and the reaction product is not easily dissolved, to replace water glass: it forms a double liquid with a mixture of silicate cement, gypsum and water - mud B, which can overcome the shortcomings of water glass and become a double-liquid grouting material with good durability and no environmental pollution.

[0006] The invention of application number CN201911039485.4 discloses an underwater curing waterproof plugging grouting reinforcement material, which comprises component A, component B and component C, wherein component A comprises 50-120 parts of epoxy resin, 5-25 parts of epoxy resin diluent, 0.2-1 parts of dispersant, 0.2-1 parts of defoamer, and 11.8 parts of leveling agent; component B comprises 20-80 parts of fast curing agent, 0.1-4 parts of silicon coupling agent; component C comprises 50-150 parts of white cement, 20-80 parts of silica powder, 20-80 parts of heavy calcium, and 50-150 parts of quartz sand. The preparation method of the reinforcement material is as follows: add component A to component B, stir for 3-5 minutes, then add component C and stir evenly. The waterproof leak-proofing grouting reinforcement material of the present invention is used for crack repair and anti-seepage reinforcement of hydraulic structures, water blocking in highways, bridges and tunnels, and civil air defense projects, concrete repair, corrosion prevention and anti-seepage of coastal bridge piers, underground pipe galleries, ships, mines and other facilities, concrete repair in underwater and humid environments, grouting reinforcement of leak-proof projects, etc., and has the advantages of good reinforcement performance and short curing time.

[0007] The grouting materials for subway roadbed leakage control need to meet the following requirements: first, the grouting liquid has the characteristic of not dispersing underwater; second, the grouting liquid coagulates and hardens quickly underwater, and the strength after 1-2 hours of grouting is greater than 5MPa; third, the grouting material should have a low self-shrinkage characteristic; fourth, the grouting material needs to have good toughness and fatigue resistance.

[0008] The above-mentioned patented technology cannot fully meet the needs of subway roadbed leakage control. The present invention adopts a composite cementitious material system to achieve underwater non-dispersion grouting, and has fast early strength development, small autogenous shrinkage, and significantly improved material toughness and fatigue resistance, which is suitable for subway roadbed grouting materials.

[0009] Traditional cement slurry uses more equipment and materials, has slow results and poor durability. The limited construction time during the operation period makes the effect even worse. It is very easy to disperse under dynamic water conditions. Cement-water-glass double liquid slurry lacks good durability and will shrink greatly during the hardening process and after solidification, resulting in repeated leakage. In addition, in the environment of flowing water, a large amount of sodium ions will be dissolved in the slurry, causing environmental pollution. In addition, the water environment will also reduce the strength after consolidation. Chemical grouting materials have disadvantages such as toxicity and high cost.

[0010] Although the grouting materials in the above patent documents have the effect of plugging leaks and reinforcing, and have their own advantages in setting time, consolidation strength, durability, etc., none of the products can be used for roadbed plugging, which requires rapid setting, fast strength growth, non-dispersion and fast underwater strength development, toughness and fatigue resistance, and good fluidity and diffusivity.

[0011] After the cement-water glass dual-liquid slurry solidifies, under the action of long-term water dissolution, the surface hydration products will continuously dissolve outward, thereby forming a porous structure on the outer surface, which will reduce its mechanical properties and weaken the plugging effect.

[0012] Chemical slurry polyurethane materials mainly stop water by foaming when in contact with water, but their foaming rate is relatively high, which may cause the subway roadbed to bulge, so they are not suitable for subway roadbed leak plugging. Although epoxy resin and acrylate materials have good plugging effects, they are expensive and toxic, and the cost of plugging leaks in large areas is too high. Summary of the invention

[0013] The present invention provides a composite grouting material for subway roadbed leakage control and a preparation method thereof. The present invention adopts a composite gelling material system, realizes underwater non-dispersion grouting, has fast early strength development, small autogenous shrinkage, and significantly improves material toughness and fatigue resistance, and is suitable for subway roadbed grouting materials.

[0014] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0015] A grouting material suitable for subway roadbed leakage control comprises component A and component B, wherein component A comprises 200-280 parts by weight of blast furnace slag powder, 100-200 parts by weight of steel slag powder, 300-500 parts by weight of water, 30-50 parts by weight of toughening agent, 20-60 parts by weight of coagulant, 5-10 parts by weight of dispersant, 0.5-2 parts by weight of flocculant, and 30-50 parts by weight of shrinkage inhibitor, and component B comprises 50-100 parts by weight of fly ash, 30-50 parts by weight of limestone powder, and 240-350 parts by weight of modified water glass.

[0016] The grade of the blast furnace slag powder is not less than S95, and the specific surface area is not less than 500kg / m 2 ;

[0017] The steel slag powder is made of converter steel slag that has been subjected to pressurized hot stuffing treatment and then ground to a specific surface area of ​​not less than 500kg / m 2 ,;

[0018] The toughening agent is a compound of polyvinyl alcohol and ethylene-vinyl acetate copolymer in a weight ratio of 1:2. Preferably, the molecular weight of the polyvinyl alcohol is not less than 17 million, and the alcoholysis degree is 88%.

[0019] The coagulant is a composite of ordinary Portland cement (PO42.5), calcium formate and magnesium sulfate, and the weight ratio of the three materials is 5:2:3.

[0020] The dispersant is one of a polycarboxylate water reducer and a naphthalene water reducer;

[0021] The flocculant is a mixture of hydroxypropyl methylcellulose ether (viscosity 200,000) and xanthan gum in a ratio of 10:1 (parts by weight);

[0022] The shrinkage inhibitor is a mixture of the shrinkage inhibitor and the magnesium-aluminum layered double metal hydroxide in a weight ratio of 8:5. The average particle size of the shrinkage inhibitor is 5-20 μm, and the intercalation anion of the magnesium-aluminum layered double metal hydroxide is sulfate.

[0023] The fly ash is ultrafine fly ash with an average particle size not exceeding 10 μm;

[0024] The limestone powder has an average particle size of no more than 5 μm;

[0025] The modified water glass is prepared by adding 2%-5% of polyethylene glycol, 1%-2% of xylitol and 5%-10% of sodium tetraborate to the total weight of the mixed slurry, heating and stirring to dissolve the mixture, the heating temperature is 40-50°C, and the duration is 30-60 minutes.

[0026] The preparation method of liquid A is as follows:

[0027] 1) First, prepare the toughening agent. First, add polyvinyl alcohol into water with a mass of 10 times and soak it to dissolve. The dissolution time at room temperature is 24-48 hours. The dissolution time when heated to 65°C-95°C is 5-12 hours. Then, mix it evenly with ethylene-vinyl acetate copolymer.

[0028] 2) Mix and stir blast furnace slag powder, shrinkage inhibitor, steel slag powder, coagulant and flocculant evenly, dissolve the dispersant in water, add it together with the toughening agent prepared in advance, stir well for 3-5 minutes, and prepare liquid A.

[0029] The preparation method of liquid B is:

[0030] 1) Pre-prepare modified water glass, add 2%-5% polyethylene glycol, 1%-2% xylitol, and 5%-10% sodium tetraborate to the total mass of the water glass, heat and stir to dissolve, the heating temperature is 40-50° C., and the duration is 30-60 minutes.

[0031] 2) Add fly ash and limestone powder to the modified water glass in sequence and stir well to obtain liquid B.

[0032] Beneficial technical effects of the present invention:

[0033] (1) Underwater non-dispersive grouting;

[0034] A flocculant is added, wherein the flocculant is a mixture of hydroxypropyl methylcellulose ether (viscosity of 200,000) and xanthan gum in a ratio of 10:1 (parts by weight).

[0035] (2) The setting time can be adjusted from 5min to 30min, and rapid setting and hardening can be achieved underwater;

[0036] A coagulant is added, wherein the coagulant is a compound of 50% (by weight) of silicate cement clinker, 20% (by weight) of calcium formate, and 30% (by weight) of magnesium sulfate.

[0037] (3) Rapid strength development, high early strength, and strength greater than 5MPa after 1-2 hours;

[0038] (4) Low shrinkage;

[0039] (5) Toughness and fatigue resistance

[0040] A toughening agent is added, wherein the toughening agent is a mixture of polyvinyl alcohol and dispersible latex powder in a weight ratio of 1:2. Preferably, the molecular weight of the polyvinyl alcohol is not less than 17 million, and the alcoholysis degree is 88%.

[0041] What technical effects are produced by the technical solution of the present invention (especially the differences and improvements over the prior art. You can write the desired technical effects here, but do not focus too much on marketing promotional text).

[0042] The technical solution of the present invention is suitable for the leakage control of subway roadbed. First, it has the conditions for underwater grouting and has the characteristic of not dispersing underwater. Second, the operation time of subway leakage control is short, so double-liquid grouting is selected. The grouting material is divided into component A and component B, and the setting time is controlled. The grouting liquid sets and hardens quickly underwater. Third, after the short-time grouting operation is completed, it can meet the normal operation of the subway. The strength reaches more than 5MPa in 2 hours, the strength can increase to 30-40MPa in one day, and the strength reaches 60-70MPa in seven days, and there is no strength shrinkage. Fourth, the shrinkage is small after the leakage control is completed, and there will be no leakage again, which is better than cement slurry and cement-water glass slurry. Fifth, it has good toughness, strong chemical corrosion resistance, excellent durability and excellent fatigue resistance under the reciprocating load of the train, and the interface bonding performance is better than cement slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Non-dispersion characteristics of grouting materials underwater

[0044] Figure 2 Effect of accelerator dosage on setting time

[0045] Figure 3 Effect of accelerator dosage on compressive strength

[0046] Figure 4 Effect of limestone powder dosage on autogenous shrinkage of alkali-activated cementitious materials

[0047] Figure 5Effect of shrinkage inhibitor dosage on autogenous shrinkage

[0048] Figure 6 Effect of toughening agent dosage on flexural strength

[0049] Depend on Figure 1 As shown, the grouting material has the property of not dispersing underwater.

[0050] Figure 2 To study the effect of coagulant on the setting time of grouting slurry, by adjusting the dosage of coagulant, the setting time can be controlled between 5min and 60min, and rapid underwater setting can be achieved.

[0051] Figure 3 This is the effect of coagulant on the compressive strength of grouting slurry. With the increase of accelerator dosage, the compressive strength does not fluctuate significantly, and the 24h strength is above 40MPa.

[0052] like Figure 4 As shown in the figure, with the increase of limestone powder content, the autogenous shrinkage rate of alkali-activated cementitious materials shows a downward trend. When the limestone powder content increases from 0% to 30%, the autogenous shrinkage decreases by 20%, indicating that limestone powder has an improving effect on the autogenous shrinkage of alkali-activated cementitious materials.

[0053] from Figure 5 It can be seen that adding 2% shrinkage inhibitor can reduce the shrinkage by 35%, and adding 4% shrinkage inhibitor can reduce the shrinkage by more than 90%. After 20 hours, the shrinkage is basically zero and continues to maintain a stable state, which solves the problem of large shrinkage of alkali-activated cementitious materials and achieves low shrinkage performance.

[0054] from Figure 6 It can be seen that the addition of toughening agent can significantly improve the flexural strength of the material. When 2% toughening agent is added, the flexural strength after 7 days is increased by 203% compared with when no toughening agent is added. DETAILED DESCRIPTION

[0055] Embodiment 1:

[0056] S1. Mix sepiolite powder and magnesium-aluminum layered double metal hydroxide in a weight ratio of 8:5 to prepare a shrinkage inhibitor, compound hydroxypropyl methylcellulose ether and xanthan gum in a weight ratio of 10:1 to prepare a flocculant, and compound ordinary Portland cement (PO42.5), calcium formate and magnesium sulfate in a weight ratio of 5:2:3 to prepare a coagulant. Add 4g of polyvinyl alcohol to 40g of water at room temperature and soak and dissolve for 24h, then mix it with ethylene-vinyl acetate copolymer to prepare a toughening agent, mix 420g of blast furnace slag powder, 80g of shrinkage inhibitor, 80g of steel slag powder, 40g of flocculant and 120g of accelerator and stir them evenly, dissolve 15g of polycarboxylic acid water reducer in 360g of water, and add it together with 40g of toughening agent prepared in advance, stir well for 3min, and prepare liquid A.

[0057] S2. Add 40g of polyethylene glycol, 20g of xylitol and 50g of sodium tetraborate to 350g of water glass with a modulus of 1.2, heat and stir to dissolve, the heating temperature is 40°C, the duration is 50min, then add 280g of fly ash and 140g of limestone powder and stir well to obtain component B slurry.

[0058] S3. Mix the pre-prepared components A and B and stir them thoroughly to obtain a grouting slurry.

[0059] Embodiment 2:

[0060] The difference from Example 1 is that the added amount of the coagulant is 80 g.

[0061] Example 3

[0062] The difference from Example 1 is that the added amount of the coagulant is 160 g.

[0063] Embodiment 4:

[0064] The difference from Example 1 is that the added amount of flocculant is 20 g.

[0065] Example 5

[0066] The difference from Example 1 is that the added amount of flocculant is 30 g.

[0067] Example 6

[0068] The difference from Example 1 is that the added amount of limestone powder is 80g.

[0069] Example 7

[0070] The difference from Example 1 is that the added amount of limestone powder is 120g.

[0071] Example 8

[0072] The difference from Example 1 is that the added amount of blast furnace slag powder is 350g, and the added amount of fly ash is 350g.

[0073] Example 9

[0074] The difference from Example 1 is that the added amount of blast furnace slag powder is 490g, and the added amount of fly ash is 210g.

[0075] Example 10

[0076] The difference from Example 1 is that the amount of shrinkage inhibitor added is 40g

[0077] Embodiment 11

[0078] The difference from Example 1 is that the amount of shrinkage inhibitor added is 20g

[0079] Example 12

[0080] The difference from Example 1 is that the water glass modulus is 1.0

[0081] Example 13

[0082] The difference from Example 1 is that the polycarboxylate water reducer is replaced by a naphthalene water reducer.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] S1. Mix 420 g of blast furnace slag powder and 80 g of steel slag powder, stir evenly, add 300 g of water and stir for 3 min to prepare liquid A.

[0086] S2. Add 40g of polyethylene glycol, 20g of xylitol and 50g of sodium tetraborate to 350g of water glass with a modulus of 1.2, heat and stir to dissolve, the heating temperature is 40°C, the duration is 50min, then add 280g of fly ash and stir thoroughly to obtain component B slurry.

[0087] S3. Mix the pre-prepared components A and B and stir them thoroughly to obtain a grouting slurry.

[0088] Comparative Example 2

[0089] The difference from Example 1 is that the water glass modulus is 1.4.

[0090] Comparative Example 3

[0091] The difference from Example 1 is that no coagulant is used.

[0092] Comparative Example 4

[0093] The difference from Example 1 is that no toughening agent is used.

[0094] Comparative Example 5

[0095] The difference from Example 1 is that no limestone powder is added.

[0096] Comparative Example 6

[0097] The difference from Example 1 is that no dispersant is added.

[0098] Table 1 is a table of raw materials for the composite materials of Examples 1-7.

[0099] Table 1

[0100]

[0101] Table 2 is a table of raw materials for the composite materials of Examples 7-14.

[0102] Table 2

[0103]

[0104]

[0105] Table 3 is a raw material table of the composite materials in Example 1 and the comparative example.

[0106] Table 3

[0107]

[0108] Table 4 is the effect data in the embodiments and comparative examples.

[0109] Table 4

[0110]

[0111] Note: “ / ” means not tested.

Claims

1. A composite grouting material for subway roadbed leakage control, characterized in that : The invention comprises component A and component B, wherein component A comprises 200-280 parts by weight of blast furnace slag powder, 100-200 parts by weight of steel slag powder, 300-500 parts by weight of water, 30-50 parts by weight of toughening agent, 20-60 parts by weight of coagulant, 5-10 parts by weight of dispersant, 0.5-2 parts by weight of flocculant, and 30-50 parts by weight of shrinkage inhibitor, and component B comprises 50-100 parts by weight of fly ash, 30-50 parts by weight of limestone powder, and 240-350 parts by weight of modified water glass; The grade of the blast furnace slag powder is not less than S95, and the specific surface area is not less than 500kg / m 2 ; The specific surface area of ​​the steel slag powder is not less than 500kg / m 2 ; The toughening agent is a compound of polyvinyl alcohol and ethylene-vinyl acetate copolymer in a weight ratio of 1:2; The coagulant is a composite of ordinary Portland cement, calcium formate and magnesium sulfate, and the weight ratio of the three materials is 5:2:3; The dispersant is one of a polycarboxylate water reducer and a naphthalene water reducer; The flocculant is a mixture of hydroxypropyl methylcellulose ether and xanthan gum in a weight ratio of 10:1; The shrinkage inhibitor is a mixture of a shrinkage inhibitor and a magnesium-aluminum layered double metal hydroxide in a weight ratio of 8:5, the average particle size of the shrinkage inhibitor is 5-20 μm, and the intercalation anion of the magnesium-aluminum layered double metal hydroxide is sulfate; The fly ash is ultrafine fly ash with an average particle size not exceeding 10 μm; The limestone powder has an average particle size of no more than 5 μm; The modified water glass is prepared by adding 2%-5% of polyethylene glycol, 1%-2% of xylitol and 5%-10% of sodium tetraborate to the total mass of the water glass, heating and stirring to dissolve the mixture, the heating temperature is 40-50°C, and the duration is 30-60 minutes.

2. A method for preparing the composite grouting material according to claim 1, characterized in that: The preparation method of liquid A is as follows: 1) First, prepare the toughening agent. First, add polyvinyl alcohol into water with a mass of 10 times and soak and dissolve it. The dissolution time at room temperature is 24-48 hours. The dissolution time when heated to 65°C-95°C is 5-12 hours. Then, mix it evenly with ethylene-vinyl acetate copolymer. 2) Mix blast furnace slag powder, shrinkage inhibitor, steel slag powder, coagulant and flocculant evenly, dissolve the dispersant in water, add it together with the toughening agent prepared in advance, stir for 3-5 minutes, and prepare liquid A; The preparation method of liquid B is: 1) Preparing modified water glass in advance, adding 2%-5% polyethylene glycol, 1%-2% xylitol, and 5%-10% sodium tetraborate to the total mass of water glass, heating and stirring to dissolve, the heating temperature is 40-50° C., and the duration is 30-60 minutes; 2) Add fly ash and limestone powder to the modified water glass in sequence and stir thoroughly to obtain liquid B; The pre-prepared components A and B are mixed and stirred to obtain a composite grouting material.

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