A hydrophobic grouting material for sand and gravel formation and preparation method thereof

Abstract

The present invention relates to a hydrophobic grouting material for a sandy pebble stratum and a preparation method thereof, wherein the hydrophobic grouting material for a sandy pebble stratum comprises a hydrophobic grouting material, and the hydrophobic grouting material comprises the following raw materials in parts by weight: 50-85 parts of cement; 0.1-1 parts of anti-water dispersant; 0.5-5 parts of hydrophobic material; 0-0.6 parts of water reducer; 0-35 parts of other additives; the hydrophobic material comprises a hydrophobic material A, and the hydrophobic material A adopts a waterproofing agent. The present invention has excellent anti-water dispersibility, stability, water erosion resistance and injectability, high solidification rate, suitable strength of stone body, and reduces the difficulty of excavation in the later construction of the grouting part.

Description

Technical Field

[0001] The invention relates to a grouting material, in particular to a hydrophobic grouting material for a sand and gravel stratum and a preparation method thereof. Background Art

[0002] The construction of urban underground space is a major trend in urban development. From the existing engineering practice, it can be seen that the construction of urban underground space is mainly in the loose Quaternary shallow buried strata, and there are large-section gravel layers in special areas. The geological conditions of gravel strata are complex, mostly in a loose state, with poor cementation, and in a dynamic water environment. From the perspective of mechanical mechanism, it is highly unstable. Therefore, during the construction process, grouting is often used to improve the gravel strata to achieve the purpose of stabilizing the strata.

[0003] At present, the grouting materials commonly used for the improvement of sand and gravel formations are hydrophilic cement slurry and cement-water glass slurry; however, engineering practice shows that for sand and gravel formations with a large permeability coefficient, dynamic water has a dilution, scouring and carrying effect on the slurry. After ordinary cement slurry is diluted by dynamic water, the water-cement ratio of the slurry increases objectively, the slurry performance deteriorates, and it cannot be effectively solidified. Its water-resistance is extremely poor, the stone formation rate is low, the water separation rate is high, and the solidification time is too long. After injection, the retention rate of cement slurry in the dynamic water sand and gravel formation is extremely low, and it cannot achieve effective water stopping and reinforcement effects. At the same time, the slurry will be washed out of the design range by dynamic water, causing a large amount of material waste and environmental pollution. Although cement-water glass slurry has obvious quick-setting and early-strength characteristics, its viscosity increases slowly before the gel reaction occurs, and it does not have the ability to resist water erosion. Under the scouring of dynamic water in the pebble layer, the slurry is greatly diluted and flows out with the groundwater. At the same time, the time interval between the initial and final setting of the slurry is short, and the anti-dispersion and anti-erosion properties of the slurry are only after the gel is formed. At this time, the slurry is no longer pumpable. Due to the high viscosity of the slurry, the diffusion ability of the slurry in the formation is reduced and cannot reach the design range. Therefore, cement-based quick-setting slurry is only suitable for dynamic water grouting projects where the slurry diffuses in a small range, and the improvement effect of grouting in dynamic water sand and pebble formations is not ideal.

[0004] To solve the above problems, the current common practice is to reduce the water-cement ratio of the grouting material (under the same conditions, the water dispersibility and stability of the grouting material with a high water-cement ratio will decrease), and add some improvers such as water-resistant dispersants, stabilizers, early strength agents, and quick-setting agents to reduce the adverse effects of dynamic water on the dilution, scouring and carrying of the grouting material. However, this practice has brought new problems, such as: the low water-cement ratio and the addition of various additives make the grouting material a paste-like slurry, which increases the viscosity of the grouting material and reduces its fluidity, thereby reducing the injectability of the grouting material, making it difficult to inject it into the sand and gravel formation during grouting. In particular, the addition of quick-setting agents makes it difficult for the grouting slurry to effectively diffuse in fractured rock mass, broken rock mass, sandy soil, fine sand layer, quicksand layer and other formations, and grouting can only be carried out by high pressure, but excessive grouting pressure will cause local formation damage and ground uplift, which is not conducive to the stability of the sand and gravel layer. In addition, the grouting materials with low water-cement ratio have a larger grouting amount (dry material, non-water raw material) per cubic meter of slurry, which not only increases the grouting cost, but also causes the strength of the stone body formed by grouting to be too high, making the excavation of the grouting area extremely difficult during the later construction process, which not only increases the labor workload but also affects the construction period.

[0005] In addition, the sand and gravel stratum is an uneven stratum, and both cement slurry and cement-water glass slurry are granular slurry materials, and are usually made of cement of ordinary particle size, which has the problems of coarse particles and uneven grading. Engineering application practice shows that such cement of ordinary particle size is difficult to inject into the sand and gravel stratum, and it is difficult to achieve a good grouting effect, thus affecting the grouting performance.

[0006] Therefore, it is of vital importance to develop a hydrophobic grouting material for sand and gravel strata and a preparation method thereof, which not only improves the water dispersibility, water erosion resistance, stability and other properties of the grouting material, but also improves the injectability of the grouting material and reduces the strength of its stone body, thereby reducing the difficulty of excavation in the later construction of the grouting site. Summary of the invention

[0007] In view of the shortcomings of current traditional grouting materials in the application of sand and gravel strata engineering, the present invention provides a hydrophobic grouting material for sand and gravel strata and a preparation method thereof. The hydrophobic grouting material for sand and gravel strata still has excellent water dispersibility and water erosion resistance, stability and injectability at a high water-cement ratio, and has a high solidification rate and appropriate strength of the stone body, thereby reducing the difficulty of excavation in the later construction of the grouting site.

[0008] Technical solution 1:

[0009] A hydrophobic grouting material for sand and gravel formations, comprising a hydrophobic grouting material, wherein the hydrophobic grouting material comprises the following raw materials in parts by weight:

[0010]

[0011] The hydrophobic material includes a hydrophobic material A, and the hydrophobic material A adopts a water-proofing agent.

[0012] As a further technical solution, the hydrophobic material A is 0.5-1 parts by weight.

[0013] As a further technical solution, the waterproofing agent is one or both of sodium methyl silicate and potassium methyl silicate; preferably sodium methyl silicate.

[0014] As a further technical solution, the hydrophobic material further includes a hydrophobic material B;

[0015] As a further technical solution, the hydrophobic material B is 1.5-4 parts by weight.

[0016] As a further technical solution, the hydrophobic material B includes one or more of hydrophobic redispersible latex powder and hydrophobic white carbon black. The hydrophobic white carbon black of the present invention can play the role of conventional white carbon black and also has hydrophobicity, playing the role of anti-water dispersion and anti-water erosion.

[0017] As a further technical solution, the water-resistant dispersant includes one or more of polyacrylamide, sodium polyacrylate, and hydroxypropyl methylcellulose; polyacrylamide is preferred.

[0018] As a further technical solution, the polyacrylamide is anionic polyacrylamide.

[0019] As a further technical solution, the cement is compounded by silicate cement and rapid hardening sulphoaluminate cement in a mass ratio of 40-60:10-25;

[0020] As a further technical solution, the silicate cement adopts ultrafine silicate cement.

[0021] As a further technical solution, the ultrafine silicate cement is cement with a fineness of 800 mesh or more.

[0022] As a further technical solution, the other auxiliary agents include one or more of a slurry stabilizer and a filler.

[0023] As a further technical solution, the slurry stabilizer includes one or more of inorganic gel and hydroxypropyl methylcellulose; wherein the hydroxypropyl methylcellulose can be used not only as a slurry stabilizer but also as an anti-water dispersant.

[0024] As a further technical solution, the water reducer includes one or both of a melamine water reducer and a polycarboxylic acid water reducer; preferably, a melamine water reducer is used.

[0025] As a further technical solution, the melamine-based water reducer adopts German BASF MELMENT F10 high-efficiency water reducer.

[0026] As a further technical solution, the filler includes one or both of white carbon black and fly ash.

[0027] As a further technical solution, it also includes water, and the weight ratio of the water to the hydrophobic grouting material (ie, the water-cement ratio) is ≥1, preferably 1.0-1.2 or preferably 1.0-1.1, or preferably =1.0.

[0028] Technical solution 2:

[0029] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0030] Step 1, after weighing each raw material by weight, cement, water-resistant dispersant, other additives, and selectively adding hydrophobic material B, and stirring until the powder is fully mixed to obtain a dry powder;

[0031] Step 2: Add the water reducing agent and the hydrophobic material A into water and stir evenly to obtain a mixed solution;

[0032] Step 3: Mix the dry powder and the mixed liquid, stir evenly, and prepare grouting slurry for sand and gravel formation.

[0033] As a further technical solution, the stirring in step 1 is carried out at room temperature.

[0034] As a further technical solution, in step 3, the stirring is rapid stirring; the speed of the rapid stirring is greater than or equal to 240 rpm.

[0035] Technical solution three:

[0036] A hydrophobic grouting material for a sandy gravel formation, comprising a hydrophobic grouting material (i.e., a non-aqueous raw material) and water, wherein the weight ratio of the water to the hydrophobic grouting material (i.e., a water-cement ratio) is ≥1, preferably 1.0-1.2, or preferably 1.0-1.1, or preferably =1.0; the hydrophobic grouting material comprises the following raw materials in parts by weight:

[0037]

[0038]

[0039] As a further technical solution, the cement is compounded by silicate cement and rapid hardening sulphoaluminate cement in a mass ratio of 40-60:10-25.

[0040] As a further technical solution, the silicate cement is ultrafine silicate cement. As a further technical solution, the fineness of the ultrafine silicate cement is greater than 800 meshes.

[0041] As a further technical solution, the polyacrylamide is anionic polyacrylamide.

[0042] As a further technical solution, the other auxiliary agents include one or more of a slurry stabilizer and a filler.

[0043] As a further technical solution, the slurry stabilizer is an inorganic gel;

[0044] As a further technical solution, the filler is fly ash.

[0045] As a further technical solution, the water reducing agent is a melamine-based water reducing agent.

[0046] Technical solution 4:

[0047] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0048] Step 1, after weighing each raw material by weight, cement, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic silica, hydrophobic redispersible latex powder and other additives are mixed, and stirred until the powders are fully mixed and uniform to obtain a dry powder;

[0049] Step 2, adding melamine-based water reducer and hydrophobic material sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0050] Step 3: Mix the dry powder and the mixed liquid, stir evenly, and prepare a grouting material for sand and gravel formations.

[0051] As a further technical solution, the stirring in step 1 is carried out at room temperature.

[0052] As a further technical solution, in step 3, the stirring is rapid stirring; the speed of the rapid stirring is greater than or equal to 240 rpm.

[0053] Technical solution five:

[0054] A hydrophobic grouting material for a sandy gravel formation, comprising a hydrophobic grouting material (i.e., a non-aqueous raw material) and water, wherein the weight ratio of the water to the hydrophobic grouting material (i.e., a water-cement ratio) is ≥1, preferably 1.0-1.2, or preferably 1.0-1.1, or preferably =1.0; the hydrophobic grouting material comprises the following raw materials in parts by weight:

[0055]

[0056]

[0057] As a further technical solution, the fineness of the ultrafine silicate cement is greater than 800 meshes.

[0058] As a further technical solution, the polyacrylamide is anionic polyacrylamide.

[0059] Technical solution six:

[0060] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0061] Step 1, weighing each raw material by weight, mixing ultrafine silicate cement, rapid hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash, and stirring until the powders are fully mixed and uniform to obtain a dry powder;

[0062] Step 2, adding melamine-based water reducer and hydrophobic material sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0063] Step 3: Mix the dry powder and the mixed liquid, stir evenly, and prepare a grouting material for sand and gravel formations.

[0064] As a further technical solution, the stirring in step 1 is carried out at room temperature.

[0065] As a further technical solution, in step 3, the stirring is rapid stirring; the speed of the rapid stirring is greater than or equal to 240 rpm.

[0066] In the present invention,

[0067] 1. The silicate cement of the present invention is used as a skeleton cementing material of the grouting material, which mainly plays a role of hydration and consolidation, and provides strength and impermeability of the material after solidification; the present invention limits the amount and particle size of the ultrafine silicate cement, and at the same time, obtains good consolidation performance and impermeability, and greatly improves the injectability of the grouting material in the sand and gravel uneven formation. Compared with the cement grouting material with ordinary particle size, the penetration range is larger.

[0068] 2. The present invention replaces part of the silicate cement by adding fast-hardening sulphoaluminate cement, which can quickly hydrate and consolidate in the system, promote the hydration of silicate cement, and accelerate the initial and final setting of the slurry. In addition, the fast-hardening sulphoaluminate cement has high early strength, which can overcome the problem of insufficient early strength of silicate cement. At the same time, the present invention controls the amount of fast-hardening sulphoaluminate cement to promote the formation of calcium sulfonate crystals, compensate for the chemical shrinkage caused by the hydration of silicate cement, improve the density of the slurry stone body, reduce the free water path, and enable the grouting material of the present invention to achieve better anti-seepage performance under high water-cement ratio conditions. In addition, the addition of fast-hardening sulphoaluminate cement also saves the addition of other cement accelerators.

[0069] 3. Inorganic gel is a trioctahedral layered silicate mineral, which belongs to two-dimensional nano mineral material. It quickly forms a three-dimensional colloidal structure under the action of water, which increases the consistency of the system. It has high suspension, thixotropy, good compatibility and chemical stability, and is an ideal thickening rheological agent for water systems. The present invention adds inorganic gel to the grouting material, which can make the mineral particles such as silicate cement, sulfoaluminate cement, fly ash and the like evenly dispersed in the system, ensuring the uniformity of the chemical reaction of each component of the slurry. At the same time, by utilizing the large amount of water retention effect of the inorganic gel, the consistency of the grouting material of the present invention can still be maintained at a stable level under the condition of a larger water-cement ratio, without affecting the flow effect of the slurry, so as to achieve the purpose of improving the grouting construction performance.

[0070] 4. The present invention adds anionic polyacrylamide to the grouting material, which is a linear high molecular polymer that can improve the overall stability and water resistance of the slurry. The mesh structure of its aqueous solution, the mechanical entanglement between chains and hydrogen bonds together form mesh nodes. A large amount of ultrafine silicate cement particles, aluminate sulfate cement particles, fly ash particles and other inorganic fillers can be filled in the free water space system between the nodes. These inorganic fillers can effectively prevent water erosion and dispersion under the cohesive force of the anionic polyacrylamide flocculant, thereby improving the water resistance and dispersion of the grouting slurry. Too much polyacrylamide will cause the polyacrylamide aqueous solution to be gel-like, so that the grouting slurry shows a sharp increase in viscosity, it is difficult to form a uniform mixed solution by stirring, the construction performance deteriorates, and the material strength decreases; therefore, the present invention limits the amount of anionic polyacrylamide added to ensure the slurry cohesion and stability of the grouting material, improve the water resistance and dispersion of the grouting material, and stabilize the slurry consistency of the grouting material within a certain range to ensure that it has good construction performance.

[0071] 5. Hydroxypropyl methylcellulose is an environmentally friendly nonionic surfactant with excellent suspension, bonding, emulsification, film-forming and other properties. The present invention adds it to the grouting material to play an excellent role in water retention, thickening and protective colloid. In addition, the present invention significantly improves the anti-water dispersibility of the grouting material under water by limiting the amount of carboxypropyl methylcellulose, but avoids the problem of increased viscosity of the grouting material caused by the addition of carboxypropyl methylcellulose, poor construction performance, and prolonged material setting time.

[0072] 6. White carbon black is a general term for ultrafine amorphous silicic acid and silicate. Its structure is a porous substance. Its composition can be expressed as SiO 2 ·nH 2 O represents, where nH 2 O exists in the form of surface hydroxyl groups; the present invention adds white carbon black to the grouting material, and the hydroxyl groups on its surface can be attached to the surface of cement particles in large quantities, thereby improving the lubricity of the particles, effectively improving the friction resistance of the grouting material in the stratum voids, and improving the injectability. In addition, the present invention limits the white carbon black to hydrophobic white carbon black, which can not only improve the injectability of the slurry, but also increase the contact angle of the slurry surface, thereby improving the anti-water dispersion and anti-water erosion performance of the grouting material. The present invention limits the amount of hydrophobic white carbon black, so that the grouting material has the best hydrophobic effect and slurry fluidity, and significantly reduces the grouting pressure during grouting.

[0073] 7. The sodium methyl silicate added in the present invention is a silicate organic compound. The silanol groups in its molecular structure react with the silanol groups in the silicate material to dehydrate and crosslink, thereby realizing the "reverse capillary effect" to form an excellent hydrophobic layer, which makes the surface of the cement particles that were originally relatively hydrophilic become relatively hydrophobic, thereby preventing the invasion of water molecules, thereby improving the anti-water dispersion and water erosion resistance of the grouting material. In addition, sodium methyl silicate also has the function of micro-expansion and increasing the density of the material. By controlling the amount of methyl silicate used, the present invention not only improves the hydrophobic effect of the grouting material, thereby improving its anti-water dispersion and water erosion effects, but also avoids the problem of increased viscosity, reduced fluidity and decreased injectability of the grouting material caused by excessive use of methyl silicate.

[0074] 8. The hydrophobic redispersible latex powder has outstanding waterproof performance. It forms a film after dispersion and plays a reinforcing role as a second adhesive: it protects the slurry from being destroyed by water after forming a film, or "secondary dispersion"; the present invention adds hydrophobic redispersible latex powder to the grouting material, so that it is distributed in the entire cement system as a reinforcing material, which not only increases the cohesive force of the grouting material, but also makes the slurry surface of the grouting material show good hydrophobic properties, improves the contact angle of the slurry surface, thereby improving the anti-water dispersion and anti-water erosion performance of the grouting material, and reduces the adverse effects of water scouring on the grouting material before solidification. The present invention limits the amount of hydrophobic redispersible latex powder, so that it improves the performance of the grouting material while avoiding the problem of increased viscosity of the grouting material and decreased injectability caused by excessive addition of the hydrophobic redispersible latex powder.

[0075] 9. Fly ash is a glassy body with extremely small particles. Due to the effect of surface tension, most of its structure is spherical, with a smooth surface and small pores. The present invention effectively improves the slurry fluidity of the grouting material and improves the injectability of the grouting material by adding fly ash. At the same time, since fly ash is cheap and easy to obtain, it also effectively reduces the cost of the grouting material. In addition, since the hydration function of fly ash is relatively weak, the addition of fly ash in the present invention further reduces the strength of the consolidated body and reduces the difficulty of excavating the grouting site.

[0076] 10. The water reducer of the present invention adopts melamine-based water reducer, which is an anionic surfactant, easily soluble in water, good in dispersion of powder materials, high in water reduction rate, good in fluidity and self-repairing properties, and can effectively reduce the viscosity of the slurry, improve fluidity and injectability, and meet the needs of grouting construction; in addition, since melamine-based water reducer does not affect the hydration time of cement, it solves the problem of insufficient slow setting of cement slurry caused by the use of polycarboxylic acid-based water reducer.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] The present invention increases the amount of water in the grouting material, reduces the amount of non-water raw materials in the grouting material by increasing the water-cement ratio of the grouting material to be greater than or equal to 1, and also reduces the strength of the stone body formed after grouting, thereby solving the problem that the strength of the stone body is too high due to the low water-cement ratio of the traditional grouting material, and the difficulty of excavation in the later construction of the grouting part. The present invention adds a hydrophobic material to the grouting material, solving the problem that the water dispersibility and water erosion resistance of the grouting material decrease sharply due to the increase of water content.

[0079] In addition, due to the increase in water-cement ratio, the stability of the slurry of the grouting material, the setting time and other properties are also deteriorated. Therefore, the present invention replaces part of the silicate cement by adding fast-hardening sulphoaluminate cement, and adds inorganic gel, hydroxypropyl methylcellulose, white carbon black and other additives to improve the problem of the deterioration of the grouting material performance caused by the increase in the water-cement ratio. Among them, the fast-hardening sulphoaluminate cement compensates for the chemical shrinkage caused by the hydration of silicate cement, improves the density of the slurry stone body, reduces the free water path, and enables the grouting material to achieve better anti-seepage performance under high water-cement ratio conditions. The synergistic effect of the fast-hardening sulphoaluminate cement and the silicate cement not only ensures sufficient grouting construction operation time, but also ensures that the material is solidified in time after being injected into the formation, without affecting the subsequent process. Among them, the hydroxypropyl methylcellulose can also play a certain degree of water dispersibility and water erosion resistance effect.

[0080] The present invention preferably uses anionic polyacrylamide as the water-resistant dispersant and sodium methyl silicate as the hydrophobic material, wherein the anionic polyacrylamide and hydroxypropyl methylcellulose act synergistically to improve the cohesion of the grouting material and prevent it from being eroded and dispersed by water;

[0081] Sodium methyl silicate and other hydrophobic materials such as hydrophobic white carbon black and hydrophobic redispersible latex powder have a synergistic effect, which changes the contact angle of the slurry surface. It not only reduces the water dispersibility and water erosion resistance of the grouting material to the level before the water content is increased, but also improves the water dispersibility and water erosion resistance of the grouting material compared with the traditional low water-cement ratio grouting raw materials. The present invention strictly controls the type and amount of water-resistant dispersant and hydrophobic material, while improving the hydrophobicity of the grouting material, it also makes the viscosity and fluidity of the grouting material within a reasonable range, avoiding excessive addition of sodium methyl silicate to affect the injectability of the grouting material.

[0082] Due to the addition of hydrophobic materials, there is a problem of poor compatibility between them and other aqueous media. Therefore, the present invention improves the dispersion effect of the grouting material by limiting the stirring speed during the preparation of the grouting material, thereby avoiding the occurrence of problems such as easy stratification and water separation of the grouting material due to the addition of hydrophobic materials.

[0083] The invention also improves the fluidity of the slurry and the injectability of the grouting material by adding fly ash, while further reducing the strength of the consolidated body.

[0084] In order to solve the injectability problem of granular slurry in sandy and gravel uneven strata, the present invention uses ultrafine silicate cement to replace ordinary silicate cement, and performs particle size grading on the grouting material to ensure the diffusion range of the grouting slurry in the stratum.

[0085] In summary, the present invention improves the water-cement ratio and adds water-resistant dispersants and hydrophobic materials, which not only improves the water-resistance, water-erosion resistance and injectability of the grouting material, avoids the formation of a paste-like grouting slurry that causes grouting difficulties, but also keeps the strength of the stone body after grouting within a suitable range. The 1d compressive strength of the present invention can meet the needs of grouting reinforcement of the pebble layer, and can also reduce the excavation strength in the later construction of the grouting part; in addition, it also reduces the amount of non-aqueous raw materials in the grouting material and reduces the cost of the grouting material. In addition, the present invention selects, gradates and controls the amount of each raw material, so that each raw material can play the maximum beneficial performance while reducing its adverse effects on the grouting material, thereby obtaining a grouting material with high injectability, good water-resistance and water-erosion resistance, and moderate strength of the consolidated body. DETAILED DESCRIPTION

[0086] In the present invention,

[0087] Ultrafine Portland Cement: Ultrafine cement with mesh size of 800 or above produced by Shandong Yingrun Intelligent New Materials Co., Ltd. is used, and its cement particles are approximately spherical;

[0088] Rapid hardening sulphoaluminate cement: Rapid hardening sulphoaluminate cement produced by Tangshan Polar Bear Building Materials Co., Ltd. is used;

[0089] Inorganic gel: Gw-818B inorganic gel produced by Wuhu Shuohua New Material Technology Co., Ltd.

[0090] Anionic polyacrylamide: AN956 standard polyacrylamide produced by Aisen (China) Flocculant Co., Ltd. is used;

[0091] Hydroxypropyl methylcellulose: HPMC produced by Shandong Heda Group Co., Ltd.

[0092] Hydrophobic silica: HB-151 hydrophobic fumed silica produced by Hubei Huifu Nanomaterials Co., Ltd.

[0093] Sodium methyl silicate: Sodium methyl silicate produced by Jinan Zhisheng Chemical Co., Ltd.;

[0094] Hydrophobic redispersible latex powder: Wacker's highly efficient hydrophobic redispersible latex powder 8034H is selected;

[0095] Fly ash: Use the first-grade fly ash produced by Hebei Kexu Building Materials Co., Ltd.;

[0096] Melamine water reducing agent: German BASF MELMENT F10 high efficiency water reducing agent is used.

[0097] The present invention is further described in detail below with reference to the embodiments.

[0098] Embodiment 1:

[0099] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0100]

[0101] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0102] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0103] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0104] Step 2, adding a water reducing agent and sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0105] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a speed of 240 rpm for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0106] Example 2

[0107] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0108]

[0109] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0110] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0111] Example 3

[0112] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0113]

[0114]

[0115] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0116] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0117] Example 4

[0118] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0119]

[0120] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0121] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0122] Example 5

[0123] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0124]

[0125]

[0126] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0127] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0128] Example 6

[0129] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0130]

[0131] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0132] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0133] Example 7

[0134] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0135]

[0136] According to calculation, in this embodiment, there are 110 parts of water, 100 parts of hydrophobic grouting material (non-aqueous raw material), and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.1.

[0137] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0138] Example 8

[0139] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0140]

[0141] According to calculation, in this embodiment, there are 110 parts of water, 100 parts of hydrophobic grouting material (non-aqueous raw material), and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.1.

[0142] A method for preparing a hydrophobic grouting material for sand and gravel formations comprises the following steps: same as Example 1.

[0143] Comparative Example 1

[0144] A grouting material for sand and gravel strata, comprising the following raw materials in parts by weight:

[0145]

[0146] According to calculation, in this embodiment, there are 50 parts of water and 99 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 0.505.

[0147] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0148] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, non-hydrophobic white carbon black, non-hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0149] Step 2, adding the water reducing agent to water, stirring evenly to obtain a mixed solution;

[0150] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a grouting material for sand and gravel formations.

[0151] Comparative Example 2

[0152] A grouting material for sand and gravel strata, comprising the following raw materials in parts by weight:

[0153]

[0154]

[0155] According to calculation, the present embodiment contains 99 parts of water and 99 parts of hydrophobic grouting material (non-aqueous raw material); the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0156] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0157] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, non-hydrophobic white carbon black, non-hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0158] Step 2, adding the water reducing agent to water, stirring evenly to obtain a mixed solution;

[0159] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a grouting material for sand and gravel formations.

[0160] Comparative Example 3

[0161] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0162]

[0163] According to calculation, the present embodiment contains 99 parts of water and 99 parts of hydrophobic grouting material (non-aqueous raw material); the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0164] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0165] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0166] Step 2, adding the water reducing agent to water, stirring evenly to obtain a mixed solution;

[0167] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0168] Comparative Example 4

[0169] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0170]

[0171] According to calculation, in this embodiment, there are 100 parts of water and 100 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0172] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0173] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, non-hydrophobic white carbon black, non-hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0174] Step 2, adding a water reducing agent and sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0175] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0176] Comparative Example 5

[0177] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0178]

[0179]

[0180] According to calculation, the present embodiment contains 97 parts of water and 97 parts of hydrophobic grouting material (non-aqueous raw material); the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0181] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0182] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0183] Step 2, adding a water reducing agent and sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0184] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0185] Comparative Example 6

[0186] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0187]

[0188] According to calculation, the present embodiment contains 99.5 parts of water and 99.5 parts of hydrophobic grouting material (non-aqueous raw material); and the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0189] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0190] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, fast-hardening sulphoaluminate cement, inorganic gel, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0191] Step 2, adding a water reducing agent and sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0192] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0193] Comparative Example 7

[0194] A hydrophobic grouting material for sand and gravel formations comprises the following raw materials in parts by weight:

[0195]

[0196] According to calculation, the present embodiment contains 99.8 parts of water and 99.8 parts of hydrophobic grouting material (non-aqueous raw material); the water-cement ratio (ratio of water to hydrophobic grouting material) is 1.0.

[0197] A method for preparing a hydrophobic grouting material for a sandy and gravel stratum comprises the following steps:

[0198] Step 1, after weighing each raw material by weight, add ultrafine silicate cement, rapid hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash into a stirrer, and slowly stir for 3 minutes at room temperature until the powder is fully mixed to obtain a dry powder;

[0199] Step 2, adding a water reducing agent and sodium methyl silicate into water, stirring evenly to obtain a mixed solution;

[0200] Step 3: After mixing the dry powder and the mixed liquid, stir rapidly at a rotation speed of 240 for 5 minutes to obtain a hydrophobic grouting material for sand and gravel formations.

[0201] Effect example 1: Grouting performance test

[0202] According to the grouting requirements of the sand and gravel formation, the grouting performance (anti-water dispersion performance, initial setting time, slurry fluidity, compressive strength, stone body permeability coefficient and other indicators) of the grouting materials prepared in each embodiment and comparative example were tested, and the experimental results are shown in Table 1-2;

[0203] Detection method:

[0204] Anti-water dispersion performance: Test the turbidity and pH value of the water for grouting materials according to the national standard GB / T 37990-2019 "Technical requirements for underwater non-dispersible concrete flocculants".

[0205] Initial setting time: The initial setting time of grouting materials is determined according to the national standard GB / T 1346-2011 "Standard water consumption, setting time and stability test method for cement";

[0206] Fluidity: The fluidity of the grouting material is measured according to the national standard GB / T 8077-2012 "Test method for homogeneity of concrete admixtures".

[0207] Compressive strength: The compressive strength of the grouting material is measured according to the national standard GB / T 17671-1999 "Test method for strength of cement mortar (ISO method)".

[0208] Stone body permeability coefficient: The stone body permeability coefficient of the grouting material is tested according to the industry standard JGJT 233 "Cement-Soil Mix Design Code".

[0209] Water erosion resistance: Determine the dynamic water retention rate of the grouting slurry;

[0210] The dynamic water retention rate refers to the mass retention rate of the slurry under the condition of dynamic water erosion during the solidification stage of the material. The specific test method is as follows:

[0211] (1) Pour the grouting slurry of each embodiment and comparative example into a cement mortar test mold (the test mold adopts JC / T 726-2005 cement mortar test mold, and the mass of the test mold is m0), scrape it flat, and weigh the mass of the test mold and the slurry m1.

[0212] (2) After 15 minutes, the mold was placed in water and flushed at a water flow rate of 0.4 m / s for 30 minutes before being taken out.

[0213] (3) After cleaning the residual water on the mold surface, weigh the mass of the test mold and slurry at this time m2;

[0214] The mass percentage of the slurry before and after scouring is calculated according to the following formula, which is the slurry dynamic water retention rate Q, thereby characterizing the slurry's ability to resist dynamic water erosion.

[0215] Q=

(m2-m0) / (m1-m0)

[0216] Q: Slurry dynamic water retention rate;

[0217] m0: test mold mass, kg;

[0218] m1: the total mass of slurry and test mold before the test, kg;

[0219] m2: the total mass of the slurry and the test mold after the test, kg;

[0220] Table 1: Test results of Examples 1 to 8

[0221]

[0222] Table 2 Comparative Examples 1 to 7 Test Results

[0223]

[0224]

[0225] Effect example 2: Grouting material stability test

[0226] Taking the slurry water separation rate as an indicator, the slurry stability test was performed on the grouting materials prepared in Example 1 and Comparative Example 5;

[0227] Slurry stability test method: The test method refers to Appendix A.2 Slurry water separation rate test of DL / T5148-2012 "Technical Specifications for Cement Grouting Construction of Hydraulic Structures".

[0228] 1. Pour 100 mL of the prepared slurry into a measuring cylinder. When the volume is close to 100 mL, use a pipette to add the slurry to the 100 mL mark.

[0229] 2. After standing for 2 hours, read the scale reading corresponding to the interface between the upper clear water and the lower slurry, and record it.

[0230] 3. Repeat the above steps and perform two measurements in total.

[0231] 4. Use the water separation rate calculation formula to calculate the average value of the two tests as the test result.

[0232] Water separation rate % = (scale reading of the slurry surface position before standing - scale reading of the slurry surface position after standing) / scale reading of the slurry surface position before standing × 100%;

[0233] Among them, the scale reading of the slurry surface position before standing is 100mL;

[0234] The experimental results are shown in Table 3;

[0235] Table 3 Slurry stability results

[0236]

[0237]

[0238] From the results in Table 3, it can be seen that the slurry stability of Example 1 is significantly higher than that of Comparative Example 5, and can meet the grouting requirements; therefore, it can be seen that: inorganic gel can significantly improve the slurry stability of grouting materials.

[0239] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A hydrophobic grouting material for sand and gravel formations, It is characterized in that It comprises water and a hydrophobic grouting material, wherein the weight ratio of the water to the hydrophobic grouting material is ≥1, and the hydrophobic grouting material comprises the following raw materials in parts by weight: 40~60 parts of ultrafine silicate cement; Rapid hardening sulphoaluminate cement 10-25 parts; 1~3 parts of inorganic gel; Polyacrylamide 0.2~0.5 parts; Hydroxypropyl methylcellulose 0.1-0.2 parts; Hydrophobic white carbon black 0.5-1 part; 0.5-1 part of sodium methyl silicate; 1~3 parts of hydrophobic redispersible latex powder; 15-30 parts of fly ash; Melamine water reducer 0.2~0.6 parts.

2. A hydrophobic grouting material for sand and gravel formations according to claim 1, It is characterized in that The polyacrylamide is anionic polyacrylamide.

3. A method for preparing the hydrophobic grouting material for sand and gravel formations according to any one of claims 1 to 2, It is characterized in that The steps include: Step 1, weighing each raw material by weight, mixing ultrafine silicate cement, rapid hardening sulphoaluminate cement, inorganic gel, polyacrylamide, hydroxypropyl methylcellulose, hydrophobic white carbon black, hydrophobic redispersible latex powder and fly ash, and stirring until the powders are fully mixed and uniform to obtain a dry powder; Step 2, adding melamine-based water reducer and hydrophobic material sodium methyl silicate into water, stirring evenly to obtain a mixed solution; Step 3: Mix the dry powder and the mixed liquid, stir evenly, and prepare a grouting material for sand and gravel formations.

4. The method for preparing a hydrophobic grouting material for sand and gravel formations according to claim 3, It is characterized in that In step 3, the stirring is rapid stirring; the speed of the rapid stirring is greater than or equal to 240 rpm.

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