Anti-seepage slope protection material as well as preparation method and application thereof

Abstract

The invention provides an anti-seepage slope protection material as well as a preparation method and application thereof. The anti-seepage slope protection material comprises a cementing material, an alkali activator and waste rock aggregate, wherein in terms of the total weight of the cementing material being 100%, the cementing material comprises 20%-80% of mudstone powder and 20%-80% of slag powder; the material simultaneously realizes resource utilization of three solid wastes, namely mudstone, slag powder and mining area barren rock, has excellent anti-seepage performance, compressive strength, anti-disturbance capability and durability, and is suitable for anti-seepage water-resisting layers of open pit coal mine dumping sites, tailing dams or industrial solid waste storage yards.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geological engineering materials, and particularly relates to a seepage-proof slope protection material and a preparation method and application thereof. BACKGROUND

[0002] The dump of an open-pit coal mine is usually directly filled with stripping material, and has a loose structure, high porosity and strong permeability. Surface runoff is prone to infiltration, making it difficult for water to stay and being not conducive to ecological restoration and vegetation reconstruction. Therefore, constructing an artificial seepage-proof layer with water-blocking performance in the dump is an important prerequisite for realizing ecological reclamation. In addition, mine solid waste mainly includes stripped rock, non-mineralized value surrounding rock and the like, and due to physical and chemical factors such as composition, hardness, integrity, impurity content and factors such as transportation distance, the use is relatively limited. A large amount of stacking will cause environmental pressure, and needs to be reasonably screened and treated to realize resource utilization.

[0003] Traditional seepage-proof slope protection materials are mainly cement or clay, but cement material production has high energy consumption and large carbon emissions, which is not conducive to green mine construction; clay resources are limited by material procurement, transportation and construction process, and have problems such as high cost, complex process and fluctuating water-blocking performance. In recent years, geopolymer materials have attracted widespread attention due to their good mechanical properties and environmental friendly characteristics. Mudstone and slag, as high-silicon aluminum mine solid waste, are rich in resources and widely distributed, and have potential cementitious activity, but mudstone alone has low strength, and slag needs to be alkali-activated to fully react.

[0004] In addition, due to the actual engineering area such as the dump of an open-pit coal mine, it is inevitable to be subjected to multiple stress loading and unloading cycles caused by the self-weight of the overlying soil and construction disturbance during service. These cyclic loads may cause crack propagation and pore network evolution in the internal structure of the material, and further affect its overall compressive strength and impermeability. Therefore, in addition to requiring low permeability and good compressive strength, the water-blocking layer material also needs to have high disturbance resistance and durability. If the material is sensitive to the disturbance caused by the cyclic load during service, the internal pores will quickly expand under the load, resulting in a significant decrease in overall impermeability and compressive strength, which is not suitable for use as a main water-blocking layer material. However, the existing technology usually only considers the permeability and compressive strength under the self-weight load of the overlying rock layer, and there are few reports on the impermeability and compressive strength of the material under cyclic load. SUMMARY

[0005] In view of the above analysis, the present application provides an anti-seepage slope protection material which makes full use of solid waste resources such as mudstone, slag and mine waste rock, and after alkali activation, not only has high anti-seepage performance and compressive strength, but also has excellent disturbance resistance and durability, which can solve at least one of the technical problems in the prior art, such as water loss caused by high permeability of the open-pit mine dump, difficulty in ecological restoration, accumulation of solid waste resources, high carbon emission and large resource consumption of traditional cement-based anti-seepage slope protection materials, and significant decrease in overall anti-seepage performance and compressive strength of the existing anti-seepage slope protection materials under the action of cyclic loading and unloading caused by the self-weight of the overlying soil and construction disturbance, realizes the resource utilization of abandoned mudstone, waste rock and industrial solid waste slag in the mine, and improves the engineering adaptability of the anti-seepage slope protection material under actual working conditions. In addition, the present application also provides a preparation method and application of the anti-seepage slope protection material.

[0006] The technical scheme of the present application is as follows: In a first aspect, the present application provides an anti-seepage slope protection material, which comprises a cementitious material, an alkali activator and a waste rock aggregate; wherein, based on the total weight of the cementitious material being 100%, the cementitious material comprises 20% to 80% of mudstone powder and 20% to 80% of slag powder.

[0007] The anti-seepage slope protection material of the present application can improve the ductility and strength of the anti-seepage slope protection material by compounding mudstone and slag. In the present application, the waste rock aggregate is derived from the self-produced waste rock in the mine (such as the open-pit mine dump), and the addition of waste rock not only improves the utilization rate of solid waste in the mine, but also greatly reduces the material cost. From the perspective of material selection, waste rock, mudstone and other materials are all produced in the mine, so compared with other aggregates, the self-produced waste rock in the mine has better adaptability with the cementitious material of the present application, which helps to improve the overall performance of the material.

[0008] In the present application, the weight percentage of mudstone powder in the cementitious material can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80% or any value between them.

[0009] In the present application, the weight percentage of slag powder in the cementitious material can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80% or any value between them.

[0010] According to some embodiments of the present application, the cementitious material comprises 30%~60% of the shale powder and 40%~70% of the slag powder, or consists of 30%~60% of the shale powder and 40%~70% of the slag powder, based on the total weight of the cementitious material.

[0011] According to some embodiments of the present application, the cementitious material comprises 30%~50% of the shale powder and 50%~70% of the slag powder, or consists of 30%~50% of the shale powder and 50%~70% of the slag powder, based on the total weight of the cementitious material.

[0012] According to some embodiments of the present application, the cementitious material comprises 25%~35% of the shale powder and 65%~75% of the slag powder, or consists of 25%~35% of the shale powder and 65%~75% of the slag powder, based on the total weight of the cementitious material.

[0013] According to some embodiments of the present application, the cementitious material comprises 35%~45% of the shale powder and 55%~65% of the slag powder, or consists of 35%~45% of the shale powder and 55%~65% of the slag powder, based on the total weight of the cementitious material.

[0014] According to some embodiments of the present application, the weight ratio of the alkali activator to the cementitious material is 1:(1~3), for example, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.2, 1:2.5, 1:2.8, 1:3 or any value therebetween. According to some embodiments of the present application, the mass ratio of the alkali activator to the cementitious material is 1:(1~2), preferably 1:(1~1.5).

[0015] According to some embodiments of the present application, the modulus of the alkali activator is 0.8~1.2. Controlling the modulus of the activator can ensure that the alkali activation reaction is sufficient, and the activity of the cementitious material is guaranteed.

[0016] According to some embodiments of the present application, the alkali activator comprises a mixture of sodium hydroxide and water glass. According to some embodiments of the present application, the mass ratio of sodium hydroxide to water glass in the alkali activator is 1:(3.5~4.5), for example, 1:3.5, 1:3.8, 1:4.0, 1:4.2, 1:4.5, etc.

[0017] According to some embodiments of the present application, the mass ratio of the waste rock aggregate to the cementitious material is (2.0 ~ 4.0): 1, for example 2: 1, 2.2: 1, 2.5: 1, 2.8: 1, 3: 1, 3.2: 1, 3.5: 1, 3.8: 1, 4: 1 or any value therebetween, preferably (2.5 ~ 3.5): 1.

[0018] According to some embodiments of the present application, the average particle size of the mudstone powder is ≤ 1 mm. In some embodiments, the average particle size of the mudstone powder is 0.01 ~ 1.0 mm. In some embodiments, the average particle size of the mudstone powder is 0.1 ~ 1.0 mm. In some embodiments, the average particle size of the mudstone powder is 0.3 ~ 0.8 mm, for example 0.5 mm.

[0019] According to some embodiments of the present application, the slag powder comprises slag powder of grade S75 or above, for example slag powder of grade S75, slag powder of grade S95, slag powder of grade S105, etc. In the present application, the grade of the slag powder is according to the grade standard specified in GB / T18046-2008.

[0020] According to some embodiments of the present application, the waste rock aggregate is selected from the sandstone stripped in the mining area. The "sandstone stripped in the mining area" refers to the sandstone layer stripped from above or around the ore body during the mining process.

[0021] According to some embodiments of the present application, the main component of the waste rock aggregate comprises SiO2, Al2O3 and CaO. In some embodiments, the content of SiO2 in the waste rock aggregate is 60 ~ 80 wt%. In some embodiments, the content of Al2O3 in the waste rock aggregate is 10 ~ 20 wt%. In some embodiments, the content of CaO in the waste rock aggregate is 1 ~ 10 wt%. According to some embodiments of the present application, the waste rock aggregate also contains MgO, Fe and K2O.

[0022] According to some embodiments of the present application, the average particle size of the waste rock aggregate is ≤ 1.5 mm. In some embodiments, the average particle size of the waste rock aggregate is ≤ 1.0 mm. In some embodiments, the average particle size of the waste rock aggregate is 0.01 ~ 1.5 mm. In some embodiments, the average particle size of the waste rock aggregate is 0.1 ~ 1.5 mm. In some embodiments, the average particle size of the waste rock aggregate is 0.5 ~ 1.5 mm. Controlling the particle size of the waste rock aggregate within a suitable range can prevent the increase of fissures and the increase of permeability due to too large particles.

[0023] According to some embodiments of the present application, water is further included in the anti-seepage revetment material. In some embodiments, the water-binder ratio of the anti-seepage revetment material is 1: (0.5 ~ 1.5), preferably 1: (0.8 ~ 1.2). In the present application, controlling the water-binder ratio within a suitable range can take into account the strength, fluidity and permeability of the material.

[0024] According to some embodiments of the present application, the anti-seepage revetment material includes the following components by weight: mudstone powder 280 ~ 1120 parts, slag powder 280 ~ 1120 parts, waste stone fine aggregate 4000 ~ 5600 parts, water glass 1100 ~ 1200 parts, sodium hydroxide 280 ~ 300 parts, and water 1300 ~ 1350 parts.

[0025] According to some embodiments of the present application, the anti-seepage revetment material includes the following components by weight: mudstone powder 560 ~ 840 parts, slag powder 560 ~ 840 parts, waste stone fine aggregate 4000 ~ 4400 parts, water glass 1100 ~ 1200 parts, sodium hydroxide 280 ~ 300 parts, and water 1300 ~ 1350 parts.

[0026] According to some embodiments of the present application, the anti-seepage revetment material includes the following components by weight: mudstone powder 420 ~ 840 parts, slag powder 560 ~ 980 parts, waste stone fine aggregate 4000 ~ 4400 parts, water glass 1100 ~ 1200 parts, sodium hydroxide 280 ~ 300 parts, and water 1300 ~ 1350 parts.

[0027] According to some embodiments of the present application, the anti-seepage revetment material includes the following components by weight: mudstone powder 420 ~ 560 parts, slag powder 840 ~ 980 parts, waste stone fine aggregate 4000 ~ 4400 parts, water glass 1100 ~ 1200 parts, sodium hydroxide 280 ~ 300 parts, and water 1300 ~ 1350 parts.

[0028] According to some embodiments of the present application, the anti-seepage revetment material includes or consists of the following components by weight: mudstone powder 420 ~ 700 parts, slag powder 700 ~ 980 parts, waste stone fine aggregate 4000 ~ 4400 parts, water glass 1100 ~ 1200 parts, sodium hydroxide 280 ~ 300 parts, and water 1300 ~ 1350 parts.

[0029] According to some embodiments of the present application, the anti-seepage slope protection material comprises or consists of, in parts by weight, 490-630 parts of mudstone powder, 770-910 parts of slag powder, 4100-4300 parts of waste stone fine aggregate, 1100-1200 parts of water glass, 280-300 parts of sodium hydroxide, and 1300-1350 parts of water.

[0030] In a second aspect, the present application provides a preparation method of the anti-seepage slope protection material according to the first aspect of the present application, comprising the following steps: mixing the cementing material with the waste stone aggregate to obtain a dry mixture; mixing the alkali activator with water to obtain a slurry; mixing the slurry with the dry mixture to obtain the anti-seepage slope protection material.

[0031] According to some embodiments of the present application, the preparation method of the anti-seepage slope protection material comprises: (S1) mixing mudstone powder and slag powder to obtain a cementing material; mixing the waste stone aggregate with the cementing material to obtain a dry mixture; mixing sodium hydroxide with water glass to obtain an alkali activator; mixing the alkali activator with water to obtain a slurry; (S2) mixing the slurry with the dry mixture to obtain the anti-seepage slope protection material.

[0032] In some embodiments, in step (S1), the waste stone aggregate is mixed with the cementing material for 2-4 minutes.

[0033] In some embodiments, in step (S1), the alkali activator is mixed with water for 3-7 minutes.

[0034] In some embodiments, in step (S1), the modulus of the water glass is 3-3.5, preferably 3.1-3.4, and more preferably 3.2-3.3.

[0035] In some embodiments, in step (S2), the mixing is performed for 100-140 seconds, preferably 110-130 seconds.

[0036] In a third aspect, the present application provides an artificial anti-seepage water barrier comprising the anti-seepage slope protection material according to the first aspect of the present application, or comprising the anti-seepage slope protection material prepared by the preparation method according to the second aspect of the present application, or prepared from the raw materials comprising the anti-seepage slope protection material according to the first aspect of the present application.

[0037] According to some embodiments of the present application, the artificial anti-seepage water barrier is an anti-seepage water barrier in an open-pit coal mine dump, a tailings dam, or an industrial solid waste storage yard.

[0038] In a fourth aspect, the present application provides application of the anti-seepage slope protection material according to the first aspect or prepared by the preparation method according to the second aspect or the artificial anti-seepage water layer according to the third aspect in ecological restoration of a mining area.

[0039] According to some embodiments of the present application, the ecological restoration of the mining area includes, but is not limited to, restoration or reconstruction of the anti-seepage layer and / or water-resisting layer of a dump of an open-pit coal mine, a tailings dam or an industrial solid waste storage yard.

[0040] Compared with the prior art, the present application has the following beneficial effects: (1) The anti-seepage slope protection material provided by the present application has high compressive strength, low permeability and excellent durability by compounding mudstone and slag at a specific ratio, using self-produced waste rock in the mining area as aggregate and using alkali activator for synergistic activation. The anti-seepage slope protection material can maintain low permeability and high compressive strength under multiple loading disturbances, effectively prevent water seepage, meet the engineering requirements of long-term water storage, reclamation and ecological restoration of the mine dump, and is particularly suitable for use as an anti-seepage cushion layer of a large-area exposed dump area and for constructing an artificial water-resisting layer of the dump of the open-pit coal mine, and has excellent structural stability and anti-seepage durability.

[0041] (2) In the anti-seepage slope protection material of the present application, the mudstone and waste rock are crushed to a smaller particle size range, which helps to improve the cementing activity of the material and improve the crack resistance and anti-seepage performance. The waste rock as aggregate can be matched with the mudstone and slag, and compared with standard sand and other aggregates, the adaptability between the cementitious materials can be improved, the material cost can be greatly reduced, and the utilization rate of solid waste in the mining area can be improved.

[0042] (3) The anti-seepage slope protection material provided by the present application not only can effectively improve the water storage and retention capacity of the dump, but also can realize resource utilization of the solid waste such as mudstone and waste rock in the mining area and resource utilization of the industrial solid waste such as slag powder, reduce the engineering cost, and has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The process flow chart for preparing the anti-seepage slope protection material in Examples 1-10 of the present application is shown. DETAILED DESCRIPTION

[0044] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0045] Unless otherwise defined, the technical terms used in the following examples and comparative examples have the same meanings as commonly understood by those skilled in the art to which this application belongs. The reagents used in the following examples and comparative examples are all conventional biochemical reagents unless otherwise specified; the raw materials, instruments and equipment used in the following examples and comparative examples can be obtained by market purchase or by existing methods; the reagent amount is the reagent amount in conventional experimental operation unless otherwise specified; the experimental method is a conventional method unless otherwise specified.

[0046] The mudstone powder used in the following experiments of the application is from Haerwusu open-pit coal mine, and its mineral composition is: quartz 22.8%, kaolinite 24.9%, orthoclase 22.3%, albite 18.1%, and muscovite 11.9%. The mudstone has a porosity ratio of 63.4%, a density of 2.3 g / cm 3 , a moisture content of 5.4%, and an expansion rate of 29.7%. The chemical composition of the mudstone can be obtained by fluorescence analysis as follows (mass percentage): SiO2 61.28%, Al2O3 15.82%, Fe2O3 6.58%, K2O 5.24%, Na2O 3.64%, and other components 7.44%.

[0047] The blast furnace slag powder used in the following experiments of the application is selected from S95 grade slag powder, and its main composition is (mass percentage): SiO2 34.61%, Al2O3 16.34%, CaO 36.72%, Fe2O3 0.96%, MgO 8.34%, K2O 0.43%, TiO2 1.96%, and other components 7.44%.

[0048] The waste stone fine aggregate used in the following experiments of the application is from a certain open-pit coal mine in Xinjiang region, which is a sandstone without sulfide. The X-ray fluorescence spectrometer (XRF) is used to determine that the aggregate mainly contains SiO2, and also contains a certain amount of Al2O3 and CaO, as well as a small amount of MgO, Fe and K2O, etc. The chemical composition is as follows (mass percentage): CaO 5.63%, SiO2 68.32%, Al2O3 16.21%, MgO 3.89%, Fe 3.59%, and K2O 2.36%.

[0049] The loess used in the following experiments of the application is selected from Quaternary Wucheng loess. The chemical composition of the loess can be obtained by fluorescence analysis as follows (mass percentage): SiO2 62.13%, Al2O3 14.15%, CaO 7.68%, Fe2O3 4.65%, MgO 2.97%, K2O 2.67%, Na2O 2.37%, TiO2 0.72%, MnO 0.17%, and other components 2.49%.

[0050] Example 1-11 The preparation process of the anti-seepage slope protection material is as shown in Figure 1 .

[0051] The anti-seepage slope protection material is prepared according to the raw material ratio (mass fraction) in Table 1 below: the mudstone powder (average particle size 0.5 mm, specific surface area 460 m 2 / kg) crushed to a particle size of ≤1 mm is mixed with the blast furnace iron ore slag powder (average particle size 40 μm) for 3 minutes to obtain a cementitious material, and then the waste stone fine aggregate (average particle size 1 mm) with a particle size of ≤1.5 mm is added to the dry mixing container for secondary mixing, and the secondary mixing time is 5 minutes to ensure uniform distribution of the aggregate and the cementitious material. After mixing, the dry mixture is obtained; the flaky sodium hydroxide is added to the liquid water glass solution with a modulus of 3.3, stirred thoroughly and cooled to room temperature to obtain an activator with a final modulus of 1.0; the activator is thoroughly mixed with water to obtain a slurry; the slurry is slowly poured into the well-mixed dry mixture, and a forced stirrer is used for stirring for 120 seconds to obtain the anti-seepage slope protection material.

[0052] In view of the reconstruction of the waterproof layer of the dump under the high-temperature condition (38-40℃) in the arid area of a certain open-pit coal mine in Xinjiang: The site survey of the dump is carried out, and the total thickness is designed to be 3 m; then the construction area is leveled, the vibrating road roller is used for 3 times of compaction treatment of the construction pavement, the flatness error is controlled to be 2 mm, and the atomized water is sprayed, the dosage is 0.5 L / m 2 , the flying dust is inhibited, and the stability of the base is ensured; A movable steel road building mold is built on the surface of the base, the mold height is 20 cm, the mold is fixed by bolts, the verticality error of the mold is ≤1 mm, and an operating gap of 15 cm is reserved outside the mold to facilitate the insertion of the vibrating tamper, then the HBT80C type concrete pump is used to pump the anti-seepage slope protection material into the mold, the ZDN-50 type plug-in vibrating tamper (frequency 2800 times / min) is used for layered compaction, the single-layer vibration time is 8 min, the compactness is ensured to be ≥96%, and the surface is leveled with a ruler; The composite geotextile (specification 400 g / m 2 ) is covered on the reconstructed waterproof layer within 1 hour after the slurry pouring is completed, and the automatic spraying system is started for water spraying and moisture curing (spraying amount 1.5 L / m 2 ·h), the humidity is ensured to be 70%, and the continuous water spraying and curing is carried out for 72 h; Twenty-four hours after pouring, the formwork and geotextile were removed. The surface integrity of the waterproof layer was checked, and the joints between layers were roughened (1 mm roughness) to enhance the bonding performance of the next layer. This process was repeated until a total of 15 waterproof layers were laid. A C30 reinforced concrete seepage barrier wall was constructed on the periphery, with a thickness of 0.5 m and a height of 1.5 m. The wall was internally reinforced with a steel mesh spaced 200 mm apart. The overall permeability of the structure was 1×10⁻⁶. -16 m 2 The artificial waterproofing layer was reconstructed.

[0053] Table 1

[0054] Comparative Example 1 The only difference from Example 2 is that “mudstone” is replaced with “loess” of equal mass fraction and average particle size of 0.5 mm.

[0055] Comparative Example 2 The only difference from Example 2 is that the "waste stone aggregate" is replaced with the same mass fraction of "ISO standard sand", the particle size range of which is 0.08 mm to 2.0 mm.

[0056] Test case When anti-seepage slope protection materials are used in actual engineering areas such as open-pit coal mine spoil heaps, they inevitably experience multiple stress loading and unloading cycles caused by the weight of the overlying soil and construction disturbances during service. These cyclic loads can cause crack propagation and pore network evolution within the material structure, thereby affecting its overall compressive strength and anti-seepage performance. Therefore, to comprehensively evaluate the anti-disturbance performance and engineering adaptability of the anti-seepage slope protection material of this application under actual working conditions, compressive strength and permeability tests were conducted under different uniaxial loading cycles.

[0057] The testing method was as follows: The WDW-300 universal testing system was used, with an upper loading limit of 1 MPa and a lower unloading limit of 0 MPa, simulating the maximum ground pressure that an open-pit mining truck (MT5500B type) might generate while operating in a spoil heap. The sample loading rate was 0.5 mm / min, and after 0, 25, 50, and 100 uniaxial loading cycles (N), the material permeability Kp was determined using the "gas steady-state method (THMC system)".

[0058] The prepared anti-seepage slope protection material belongs to rock material, and the seepage test is carried out by a steady state method. The anti-seepage slope protection material contains mudstone material, which is easy to expand when meeting water, and is easy to cause the material to expand to fill the pores in the material, so that the internal structure of the material changes, and the seepage evolution rule cannot be studied. Therefore, in this test, gas seepage is selected, and in order to ensure the safety of the test, argon is used throughout the test. Temperature will affect the molecular structure of the gas itself, in order to eliminate the influence of temperature, the test is carried out in a room with an air conditioner temperature of 20 DEG C, and the confining pressure of the pressure chamber is set to 2 MPa. The test steps are as follows: ①The sample is sealed and packaged to prevent debris from entering the instrument; ②Check whether the test instrument is running normally; ③Put the sample into the instrument, close the instrument valve, and ensure the sealing of the instrument; ④Open the gas pump and add confining pressure to 2 MPa; ⑤Open the software to record data, open the gas valve, and wait for 30 min; ⑥Save the data, unload the confining pressure; ⑦After taking out the sample, seal it; ⑧Collect and process the data.

[0059] The compressive strength of the material is measured according to the "Engineering Rock Mass Test Method Standard" GB / T 50266.

[0060] The uniaxial compressive strength and permeability of the anti-seepage slope protection materials of examples 1-4 under different uniaxial cyclic loading and unloading times are shown in tables 2 and 3 respectively.

[0061] Table 2

[0062] Table 3

[0063] As can be seen from tables 2 and 3, with the increase of the amount of mudstone in the cementing material and the decrease of the amount of slag powder, the compressive strength of the material will decrease, but the permeability will also decrease, and the anti-seepage performance will improve. Overall, the anti-seepage slope protection materials prepared in examples 1, 2, 3 and 4 all have high compressive strength and low permeability, which can meet the use requirements of artificial anti-seepage layer and water-resisting layer of open-pit coal mine dump. Among them, the anti-seepage slope protection material prepared in example 1 has the highest compressive strength, and the anti-seepage slope protection material prepared in example 4 has the smallest permeability.

[0064] In the multiple uniaxial loading cycle experiment, compared with the uniaxial loading cycle 0 times, after the uniaxial loading cycle 100 times, the 7-day and 28-day compressive strength reduction rate and permeability increase of examples 1-4 are shown in the following table 4.

[0065] Table 4

[0066] Compressive strength reduction rate = difference between compressive strength after 0 times of uniaxial loading cycle and 100 times of uniaxial loading cycle divided by compressive strength after 0 times of uniaxial loading cycle.

[0067] Permeability increase rate = difference between permeability after 0 times of uniaxial loading cycle and 100 times of uniaxial loading cycle divided by permeability after 0 times of uniaxial loading cycle.

[0068] It can be seen that the compressive strength reduction rate of the anti-seepage slope protection materials of Examples 1-4 is within 20% after 100 times of uniaxial loading cycle, and the permeability increase rate is within 60%. Among them, the compressive strength reduction rate of the anti-seepage slope protection materials of Examples 1-3 is lower than that of Example 4, which indicates that the material structure is dense, the pore changes slowly, and has more excellent anti-disturbance performance, and is more suitable as a main water-resisting layer material; the permeability of the anti-seepage slope protection material of Example 4 is the lowest, which shows excellent anti-seepage performance, but due to the high content of mudstone and low cementing strength, it is suitable for use as a cover-type water-resisting layer or in a no-load area.

[0069] Using the same method, the compressive strength reduction rate and the permeability increase rate of the anti-seepage slope protection materials of Examples 5-11 and Comparative Examples 1-2 after 0 times of uniaxial loading cycle and 100 times of uniaxial loading cycle are measured, and the results are shown in Tables 5 and 6, respectively.

[0070] Table 5

[0071] Table 6

[0072] As can be seen from Tables 5 and 6, the results of Examples 5, 6 and 7 show that as the amount of mudstone in the cementing material increases and the amount of slag powder decreases, the compressive strength of the material will decrease, but the permeability will also decrease, and the anti-seepage performance will improve. The results of multiple uniaxial loading cycles show that Examples 5-7 all have high anti-disturbance performance, and Example 5 is slightly better than Examples 6 and 7.

[0073] Compared with Example 2, Example 8 reduces the amount of alkali activator, and the compressive strength and anti-seepage performance are not as good as Example 2, and after 100 times of uniaxial loading cycle, the compressive strength reduction rate and the permeability increase rate are higher than Example 2, indicating that the anti-disturbance performance has also decreased.

[0074] Compared with Example 2, Example 9 reduces the amount of waste rock, and the compressive strength and anti-seepage performance of the anti-seepage slope protection material are improved. The results of multiple uniaxial loading cycles show that the compressive strength reduction rate of Example 9 is higher than that of Example 2. It can be seen that compared with Example 9, Example 2 has better anti-disturbance ability under multiple uniaxial loading cycles on the premise of meeting the use requirements of the anti-seepage water-resisting layer, and also greatly improves the utilization rate of waste rock in the mining area.

[0075] Compared with Example 2, the amount of waste rock in Example 10 is increased, the compressive strength and impermeability of the anti-seepage slope protection material are reduced, but the use requirements of the anti-seepage water-resisting layer can be met. The results of multiple uniaxial loading cycles show that, compared with 0 times of uniaxial loading cycles, the 7-day and 28-day compressive strength reduction rates of Example 10 are higher than those of Example 2 after 100 times of uniaxial loading cycles, and the disturbance resistance is reduced.

[0076] Compared with Example 2, the particle size range of the waste rock aggregate used in Example 11 is larger, the compressive strength and impermeability of the anti-seepage slope protection material are reduced, and the results of multiple uniaxial loading cycles show that, compared with 0 times of uniaxial loading cycles, the 7-day and 28-day compressive strength reduction rates and the permeability increase of Example 11 are increased after 100 times of uniaxial loading cycles, and the disturbance resistance is reduced.

[0077] Compared with Example 2, the cementitious material of Comparative Example 1 is compounded with loess and slag powder, and the compressive strength and impermeability of the anti-seepage slope protection material are significantly reduced. The results of multiple uniaxial loading cycles show that, compared with 0 times of uniaxial loading cycles, the 7-day and 28-day compressive strength reduction rates and the permeability increase of Comparative Example 1 are higher after 100 times of uniaxial loading cycles, and the disturbance resistance is significantly lower than that of Example 2.

[0078] As can be seen from Comparative Example 2, the anti-seepage slope protection material obtained by using waste rock aggregate has almost the same compressive strength and impermeability compared with that obtained by using standard sand.

[0079] It should be noted that the above-described examples are only used to explain the present application and do not constitute any limitation on the present application. The present application is described by referring to typical examples, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The present application can be modified as specified within the scope of the claims of the present application, and the present application can be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and examples, it does not mean that the present application is limited to the specific examples disclosed therein, on the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. A seepage-proof slope protection material, comprising a cementitious material, an alkali activator, and waste rock aggregate; wherein, Based on the total weight of the cementing material as 100%, the cementing material includes 20% to 80% mudstone powder and 20% to 80% slag powder.

2. The seepage-proof slope protection material according to claim 1, characterized in that, The weight ratio of the alkali activator to the cementitious material is 1:(1~3), preferably 1:(1~2), more preferably 1:(1~1.5); and / or The weight ratio of the waste stone aggregate to the cementitious material is (2.0 ~ 4.0): 1, preferably (2.5 ~ 3.5):

1.

3. The seepage-proof slope protection material according to claim 1 or 2, characterized in that, The average particle size of the mudstone powder is ≤1 mm; and / or The slag powder includes slag powder of grade S75 or higher; and / or The waste rock aggregate is selected from stripped sandstone from the mining area; and / or The average particle size of the waste stone aggregate is ≤1.5mm, preferably ≤1.0mm.

4. The seepage-proof slope protection material according to any one of claims 1 to 3, characterized in that, The alkaline activator comprises a mixture of sodium hydroxide and water glass; preferably, the mass ratio of sodium hydroxide to water glass in the alkaline activator is 1:(3.5~4.5); and / or The modulus of the alkali activator is 0.8 to 1.

2.

5. The seepage-proof slope protection material according to any one of claims 1 to 4, characterized in that, The seepage-proof slope protection material also includes water; preferably, the water-cement ratio of the seepage-proof slope protection material is 1:(0.5~1.5), more preferably 1:(0.8~1.2).

6. The seepage-proof slope protection material according to any one of claims 1 to 5, characterized in that, Based on the total weight of the cementing material as 100%, the cementing material includes 30% to 60% mudstone powder and 40% to 70% slag powder; Preferably, the cementing material comprises 30% to 40% mudstone powder and 60% to 70% slag powder, based on the total weight of the cementing material as 100%.

7. The seepage-proof slope protection material according to any one of claims 1 to 6, characterized in that, By weight, the seepage-proof slope protection material comprises the following components: 280-1120 parts mudstone powder, 280-1120 parts slag powder, 4000-5600 parts waste rock fine aggregate, 1100-1200 parts water glass, 280-300 parts sodium hydroxide, and 1300-1350 parts water; Preferably, by weight, the seepage-proof slope protection material comprises the following components: 420-840 parts mudstone powder, 560-980 parts slag powder, 4000-4400 parts waste rock fine aggregate, 1100-1200 parts water glass, 280-300 parts sodium hydroxide, and 1300-1350 parts water; Preferably, the seepage-proof slope protection material comprises the following components by weight: 420-560 parts mudstone powder, 840-980 parts slag powder, 4000-4400 parts waste stone fine aggregate, 1100-1200 parts water glass, 280-300 parts sodium hydroxide, and 1300-1350 parts water.

8. A method for preparing an impermeable slope protection material as described in any one of claims 1 to 7, comprising the following steps: The cementitious material is mixed with waste stone aggregate to obtain a dry mixture; The alkaline activator is mixed with water to obtain a slurry; The slurry is mixed with the dry mix to obtain the seepage-proof slope protection material.

9. An artificial impermeable layer comprising the impermeable slope protection material according to any one of claims 1 to 7 or the impermeable slope protection material obtained by the preparation method according to claim 8, or prepared from raw materials comprising the impermeable slope protection material according to any one of claims 1 to 7; Preferably, the artificial seepage-proof waterproof layer is a seepage-proof waterproof layer in open-pit coal mine spoil heaps, tailings dams, or industrial solid waste dumps.

10. The application of the seepage-proof slope protection material as described in any one of claims 1 to 7, or the seepage-proof slope protection material obtained by the preparation method described in claim 8, or the artificial seepage-proof waterproof layer described in claim 9, in the ecological restoration of mining areas; Preferably, the ecological restoration of the mining area includes the repair or reconstruction of the impermeable layer and / or waterproof layer of the open-pit coal mine spoil heap, tailings dam, or industrial solid waste dump.

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