Ultrahigh-ductility lithium slag concrete and preparation method thereof

Abstract

The invention relates to the technical field of cement-based building materials, in particular to ultrahigh-ductility lithium slag concrete and a preparation method thereof. Comprising 390 to 450 parts of cement, 40 to 120 parts of modified lithium slag powder, 500 to 700 parts of fly ash, 300 to 500 parts of quartz sand, 10 to 20 parts of polyethylene fiber, 30 to 40 parts of a water-absorbing polymer, 3 to 6 parts of a high-efficiency water reducing agent, 1 to 3 parts of a thickening agent and 330 to 460 parts of water. By adopting the components, through activity excitation and doping amount optimization of the lithium slag, the filling effect of the fly ash and the humidity adjusting function of the water-absorbing polymer are combined, and the polyethylene fiber is introduced, so that the large deformation and multi-seam cracking capability of the ultrahigh-ductility lithium slag concrete are realized; the preparation method has the remarkable advantages of being environmentally friendly, low in cost, high in performance and the like, and is suitable for various building and engineering application scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of cement-based building materials, and particularly to a super high ductility lithium slag concrete and a preparation method thereof. Background Art

[0002] Lithium slag is a large amount of industrial waste residue discharged during the production process of the lithium salt industry (such as lithium carbonate, lithium chloride, and lithium hydroxide, etc.). It is the residue after chemical treatments such as high-temperature roasting and acid-base dissolution of lithium ore or spodumene. For every 1 ton of lithium carbonate produced, about 8 - 10 tons of lithium slag will be produced. In recent years, the demand for lithium salts in China has increased rapidly, and the output of lithium slag has risen sharply. If not utilized, the large-scale stacking of lithium slag not only occupies land resources but also poses a serious threat to the ecological environment. Therefore, it is urgent to develop effective ways for the resource utilization of lithium slag.

[0003] Lithium slag has high pozzolanic activity and contains a certain amount of active CaO and SO3, enabling it to undergo a secondary pozzolanic reaction with cement hydration products (such as Ca(OH)2) under appropriate conditions to form new hydration products and improve the microstructure of the matrix. Based on the above characteristics, lithium slag can be used as a mineral admixture in cement-based materials to partially replace cement or other cementitious materials.

[0004] Patent CN202011402365.9 discloses a preparation method of lithium slag concrete. This method uses a specific raw material ratio, including cement, fly ash, water, sand, stone, as well as additives and modified lithium slag materials. The modified lithium slag material is made of lithium slag powder, cyclohexylaminomethyltriethoxysilane, and ethyl cellulose. The lithium slag concrete of this patent has good flexural performance, and its preparation method includes steps such as mixing materials and preparing concrete, aiming to improve the flexural performance of the product. However, when facing tensile or bending loads, its plastic deformation ability may be insufficient, leading to the risk of brittle fracture. In addition, the brittleness problem of lithium slag concrete may affect its durability, especially in applications that require high ductility.

[0005] Patent CN202111637600.5 discloses a method for preparing lithium slag concrete completely using industrial waste residues. This kind of concrete includes lithium slag, alkali activator, water reducer, steel slag with different particle sizes, and water. The lithium slag is a by-product generated during the process of using spodumene to produce lithium sulfate by the sulfuric acid method after calcination. By reasonably proportioning each raw material, the obtained lithium slag concrete has a 28-day strength greater than 24.1 MPa and a fluidity greater than 189 mm, effectively utilizing resources and protecting the environment. However, the obtained concrete has insufficient ductility and there is a risk of brittle fracture; the stacking of lithium slag may cause environmental problems and additional environmental protection measures are required; the durability is limited by low toughness and crack resistance, affecting the long-term performance.

[0006] Ultra-high Ductile Concrete (UHDC) is a new type of cement-based composite material with excellent mechanical properties and durability. It has attracted widespread attention for its excellent tensile ductility and crack resistance. Unlike the brittle fracture behavior of traditional concrete, ultra-high ductile concrete can exhibit significant strain hardening characteristics under tensile loads, forming multi-crack refinement cracks at the micro level, thereby significantly improving its deformation performance and durability. In the face of the brittleness problems, environmental impacts and durability problems in existing technologies, the development of ultra-high ductile lithium slag concrete provides an innovative solution. Summary of the invention

[0007] The purpose of the present invention is to provide an ultra-high ductility lithium slag concrete and a preparation method thereof. The modified lithium slag powder after alkaline excitation is used as an auxiliary cementitious material, combined with the filling effect of fly ash, and at the same time, a water-absorbing polymer is introduced to adjust the humidity and polyethylene fiber is introduced to achieve strain hardening. The prepared ultra-high ductility lithium slag concrete has ultra-high tensile strain capacity and excellent strain hardening behavior.

[0008] To achieve the above-mentioned purpose, the present invention provides an ultra-high ductility lithium slag concrete, wherein the components, by weight, include 390-450 parts of cement, 40-120 parts of modified lithium slag powder, 500-700 parts of fly ash, 300-500 parts of quartz sand, 10-20 parts of polyethylene fiber, 30-40 parts of water-absorbing polymer, 3-6 parts of high-efficiency water reducing agent, 1-3 parts of thickener and 330-460 parts of water.

[0009] Preferably, the amount of cement added is controlled to account for 55-65% of the total mass of the ultra-high ductility lithium slag concrete.

[0010] The present invention can ensure the early strength of ultra-high ductility lithium slag concrete by adding an appropriate amount of cement, and avoid the problems of increased shrinkage and decreased durability caused by excessive cement dosage.

[0011] Preferably, the added amount of modified lithium slag powder is 10-20% of the total mass of the ultra-high ductility lithium slag concrete.

[0012] The modified lithium slag powder of the present invention is alkaline excited by an alkaline activator during the modification process, thereby improving SiO2, Al2O3, and CaO in the modified lithium slag powder, thereby giving the modified lithium slag good volcanic ash activity, and can undergo secondary reaction with the hydration product Ca(OH)2 to generate new CSH gel and ettringite, thereby improving the microscopic pore structure of the ultra-high ductility lithium slag concrete, thereby improving the strength and durability of the ultra-high ductility lithium slag concrete. At the same time, the modified lithium slag powder also has a certain filling effect, and can effectively fill the pores in the ultra-high ductility lithium slag concrete, further improving the density of the ultra-high ductility lithium slag concrete matrix.

[0013] Preferably, the polyethylene fiber has a length of 12-24 mm, a diameter of 20-30 μm, a length-to-diameter ratio of 500-800, an elongation at break of 2-3%, and a tensile strength of 2800-3500 MPa.

[0014] In the present invention, polyethylene fibers are used as the reinforcing material for ultra-high ductility lithium slag concrete. By controlling the length-to-diameter ratio of the polyethylene fibers, the interfacial bonding force and the bridging supplementary residual energy of the polyethylene fiber / ultra-high ductility lithium slag concrete matrix are regulated. When the volume fraction of the polyethylene fibers is 1-2% of the total volume of the ultra-high ductility lithium slag concrete, the ultra-high ductility requirement of the lithium slag concrete can be achieved.

[0015] In the present invention, the length-to-diameter ratio of the polyethylene fibers is controlled. When the length-to-diameter ratio is too small, the high strength of the polyethylene fibers often cannot be exerted due to their premature extraction from the cement matrix. When the length-to-diameter ratio is too large, the probability of fracture failure during the extraction of the polyethylene fibers will increase, and the polyethylene fibers after fracture will withdraw from work and no longer provide bridging action.

[0016] Preferably, the water-absorbing polymer is a polyacrylic acid-acrylamide type superabsorbent resin with a particle size of 150-620 μm. The dosage of the water-absorbing polymer (SAP) is 0.1-0.2% of the total mass of the ultra-high ductility lithium slag concrete.

[0017] The water-absorbing polymer added in the present invention can release the absorbed water when the internal humidity is insufficient, continue the hydration reaction, and prevent cracks caused by drying shrinkage. SAP can effectively inhibit the generation of early drying shrinkage cracks and improve the overall crack resistance of ultra-high ductility lithium slag concrete.

[0018] Preferably, the quartz sand is medium-fine sand with a particle size of 0.2-0.6 mm, a fineness modulus of 2.5-3.0, and a mud content of less than 1%.

[0019] In the present invention, the quartz sand constitutes the skeleton structure of the ultra-high ductility lithium slag concrete, providing the necessary compactness and dimensional stability for the ultra-high ductility lithium slag concrete. The particle shape and particle size distribution of the quartz sand optimize the fluidity of the ultra-high ductility lithium slag concrete. Compared with natural desert sand or river sand, the quartz sand has higher purity and more uniform particle size distribution, thus significantly improving the mechanical properties and crack resistance of the ultra-high ductility lithium slag concrete.

[0020] Preferably, the fly ash has a particle size of 50-400 μm and a specific surface area of 400-600 m 2 / kg, and the fly ash is one or more of Class I fly ash and Class II fly ash.

[0021] The present invention utilizes the reactive components (such as SiO2 and Al2O3) in fly ash to react with Ca(OH)2 to generate C-S-H gel and ettringite, enhancing the compactness and durability of the matrix structure of ultra-high ductility lithium slag concrete.

[0022] In the present invention, when fly ash and modified lithium slag powder are used in combination, the mechanical properties and crack resistance of ultra-high ductility lithium slag concrete can be synergistically improved through the secondary pozzolanic reaction, further enhancing the ductility and durability. The fine particles of fly ash can fill the micro-pores in ultra-high ductility lithium slag concrete, reducing the porosity and improving the impermeability and frost resistance.

[0023] Preferably, the thickening agent is cellulose ether, and the cellulose ether is hydroxypropyl methyl cellulose ether. The addition amount of the thickening agent is 0.03 - 0.05% of the total mass of ultra-high ductility lithium slag concrete.

[0024] The present invention uses hydroxypropyl methyl cellulose ether as a thickening agent to improve the cohesion of ultra-high ductility lithium slag concrete and prevent construction defects caused by fiber or aggregate separation.

[0025] Preferably, the high-range water reducer is a polycarboxylate-based water reducer, with a water reduction rate of 30 - 40%, a solid content of 40 - 50%, and the content of Na2SO4 < 2wt%, and the content of CI - content < 0.01wt%.

[0026] The preparation method of the above-mentioned ultra-high ductility lithium slag concrete includes the following steps: S1. Weigh 390 - 450 parts of cement, 40 - 120 parts of modified lithium slag powder, 500 - 700 parts of fly ash, 300 - 500 parts of quartz sand, 10 - 20 parts of polyethylene fiber, 30 - 40 parts of water-absorbing polymer, 3 - 6 parts of high-range water reducer, 1 - 3 parts of thickening agent, and 330 - 460 parts of water by mass; S2. Add the cement, modified lithium slag powder, quartz sand, fly ash, and high-range water reducer into a mixer and slowly stir for 3 - 5 min until evenly mixed to obtain dry materials; S3. Add water to the dry materials in S1 and continue to slowly stir for 2 - 3 min. After the dry materials are liquefied, add the thickening agent and stir evenly to obtain a mixture; S4. Slowly add the polyethylene fiber to the mixture in S3 and quickly stir for 2 - 3 min until the polyethylene fiber is evenly dispersed to obtain a slurry; S5. Pour the slurry in S4 into a mold, vibrate and form it, seal it, and cure it at room temperature for 28 days to obtain ultra-high ductility lithium slag concrete.

[0027] Preferably, in S1, the preparation steps of the modified lithium slag powder are as follows: after recycling the waste lithium slag, it is successively crushed, finely ground, washed and dried. The dried lithium slag powder is mixed with an alkaline activator and soaked, and after complete reaction, it is screened to obtain the modified lithium slag powder.

[0028] Preferably, in S2 and S3, the rotation speed of the slow stirring is 100 - 135 r / min.

[0029] Preferably, in S4, the rotation speed of the fast stirring is 185 - 230 r / min.

[0030] Therefore, the present invention adopts the above-mentioned ultra-high ductility lithium slag concrete and its preparation method, and its characteristics and excellent effects are as follows: 1. The ultra-high ductility lithium slag concrete provided by the present invention effectively improves the ductility of the ultra-high ductility lithium slag concrete by controlling the material ratio and preparation method, enabling it to withstand significant plastic deformation when subjected to tensile or bending loads, thereby significantly enhancing the seismic performance and safety of the ultra-high ductility lithium slag concrete structure; 2. The ultra-high ductility lithium slag concrete provided by the present invention partially replaces cement by adding modified lithium slag powder, solves the environmental problem of lithium slag stacking, promotes the resource utilization of industrial waste residues, provides a new solution for low-carbon buildings, and promotes sustainable development; 3. The modified lithium slag powder used in the present invention has pozzolanic activity and filling effect, can effectively improve the pore structure of the microscopic ultra-high ductility lithium slag concrete, optimize the performance of the interfacial transition zone, thereby improving the strength and durability of the ultra-high ductility lithium slag concrete, and reducing the production cost and carbon footprint; 4. The preparation method provided by the present invention is simple to operate, and the prepared ultra-high ductility lithium slag concrete has excellent strain hardening and tensile ductility. The axial tensile ductility exceeds 3%, and the crack width remains at 87 - 100 µm, significantly improving the brittle performance and crack control ability of the concrete; 5. The preparation method provided by the present invention is low-carbon, green and environmentally friendly, realizes the resource utilization of industrial waste residues, reduces the consumption of ordinary Portland cement, reduces carbon emissions, and has significant environmental and economic benefits.

[0031] Next, through examples, the technical solutions of the present invention will be further described in detail. Specific Embodiments

[0032] The present invention will be further described below in conjunction with embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention pertains. The above-mentioned features mentioned in the present invention or the features mentioned in the specific examples can be combined arbitrarily. These specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The raw materials used in the embodiments are all well-known and commercially available chemical raw materials unless otherwise specified.

[0033] The preparation steps of the modified lithium slag powder are as follows: Recover the waste lithium slag generated during the industrial production of lithium salts, and successively carry out crushing, fine grinding, washing and drying. During crushing, first coarse crush and then fine grind. Coarse crushing is carried out in a jaw crusher. After coarse crushing, screening is carried out using a stone sand sieve to remove particles larger than 5 mm, and the particles suitable for subsequent treatment are retained and enter fine grinding. Fine grinding is carried out in a rotary ball mill until lithium slag powder with a specific surface area of 1100 - 1200 m 2 / kg is obtained. The fine-ground lithium slag powder is screened to remove the particles that are not completely finely ground to ensure that the finally obtained lithium slag powder is delicate and uniform. Wash the fine-ground lithium slag powder to remove impurities, and dry it to a conventional humidity in an environment of 60 - 80 °C. Mix the dried lithium slag powder with an alkaline activator (Na2CO3 or NaOH) and soak it. The addition amount of the alkaline activator is 2 - 5% of the mass of the lithium slag, and the activation time is 24 - 48 hours. After complete reaction, screen to remove the unreacted solid particles to obtain the modified lithium slag powder.

[0034] The present invention adopts a combined treatment method of mechanical grinding and alkaline activation, which significantly enhances the pozzolanic reactivity of lithium slag powder and improves the mechanical properties and ductility of ultra-high ductility lithium slag concrete. The above-mentioned modification method provides a new way for the large-scale resource utilization of lithium slag, and by effectively utilizing lithium slag, it reduces the harm of lithium slag to nature; alleviates the shortage and insufficient supply of other building materials, and realizes the reuse of industrial waste.

[0035] The cement used in the preparation processes of the examples and comparative examples is 42.5 ordinary Portland cement. The particle size of the quartz sand is 0.3 - 0.6 mm, and the fineness modulus is 2.5 - 3.0. The length of the polyethylene fiber is 18 mm, the diameter is 25 µm, and the aspect ratio is 720.

[0036] Example 1 S1. Weigh 400 parts of cement, 80 parts of modified lithium slag powder, 600 parts of fly ash, 400 parts of quartz sand, 15 parts of polyethylene fiber, 35 parts of water-absorbing polymer, 4 parts of high-range water reducer, 2 parts of thickener and 350 parts of water by mass.

[0037] S2. Add cement, modified lithium slag powder, quartz sand, fly ash, and high-range water reducer into a mixer, and stir slowly at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0038] S3. Add water to the dry materials in S1 and continue to stir slowly for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a mixture.

[0039] S4. Slowly add polyethylene fibers to the mixture in S3, and stir quickly at 185 - 230 r / min for 2 - 3 min until the polyethylene fibers are evenly dispersed to obtain a slurry.

[0040] S5. Pour the slurry in S4 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain ultra-high ductility lithium slag concrete.

[0041] Example 2 S1. Weigh 420 parts of cement, 100 parts of modified lithium slag powder, 650 parts of fly ash, 450 parts of quartz sand, 17 parts of polyethylene fibers, 30 parts of water-absorbing polymer, 5 parts of high-range water reducer, 3 parts of thickening agent, and 360 parts of water by mass.

[0042] S2. Add cement, modified lithium slag powder, quartz sand, fly ash, and high-range water reducer into a mixer, and stir slowly at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0043] S3. Add water to the dry materials in S1 and continue to stir slowly for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a mixture.

[0044] S4. Slowly add polyethylene fibers to the mixture in S3, and stir quickly at 185 - 230 r / min for 2 - 3 min until the polyethylene fibers are evenly dispersed to obtain a slurry.

[0045] S5. Pour the slurry in S4 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain ultra-high ductility lithium slag concrete.

[0046] Example 3 S1. Weigh 390 parts of cement, 60 parts of modified lithium slag powder, 550 parts of fly ash, 300 parts of quartz sand, 20 parts of polyethylene fibers, 40 parts of water-absorbing polymer, 4.5 parts of high-range water reducer, 2.5 parts of thickening agent, and 340 parts of water by mass.

[0047] S2. Add cement, modified lithium slag powder, quartz sand, fly ash, and high-range water reducer into a mixer, and stir slowly at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0048] S3. Add water to the dry materials in S1 and continue slow stirring for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a mixture.

[0049] S4. Slowly add polyethylene fibers to the mixture in S3 and quickly stir at 185 - 230 r / min for 2 - 3 min until the polyethylene fibers are evenly dispersed to obtain a slurry.

[0050] S5. Pour the slurry in S4 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain ultra-high ductility lithium slag concrete.

[0051] Comparative Example 1 S1. Weigh 500 parts of cement, 600 parts of fly ash, 400 parts of quartz sand, 5 parts of polyethylene fibers, 35 parts of water-absorbing polymer, 4 parts of high-range water reducer, 2 parts of thickening agent and 350 parts of water by mass.

[0052] S2. Add cement, quartz sand, fly ash and high-range water reducer into a mixer and slowly stir at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0053] S3. Add water to the dry materials in S1 and continue slow stirring for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a mixture.

[0054] S4. Slowly add polyethylene fibers to the mixture in S3 and quickly stir at 185 - 230 r / min for 2 - 3 min until the polyethylene fibers are evenly dispersed to obtain a slurry.

[0055] S5. Pour the slurry in S4 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain concrete.

[0056] Comparative Example 2 S1. Weigh 420 parts of cement, 80 parts of lithium slag powder, 600 parts of fly ash, 400 parts of quartz sand, 35 parts of water-absorbing polymer, 4 parts of high-range water reducer, 2 parts of thickening agent and 340 parts of water by mass.

[0057] S2. Add cement, lithium slag powder, quartz sand, fly ash and high-range water reducer into a mixer and slowly stir at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0058] S3. Add water to the dry materials in S1 and continue slow stirring for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a slurry.

[0059] S4. Pour the slurry in S3 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain concrete.

[0060] Comparative Example 3 S1. Weigh 420 parts of cement, 80 parts of lithium slag powder, 600 parts of fly ash, 400 parts of quartz sand, 30 parts of polyethylene fiber, 35 parts of water-absorbing polymer, 4 parts of high-range water reducer, and 340 parts of water by mass.

[0061] S2. Add the cement, lithium slag powder, quartz sand, fly ash, and high-range water reducer into a mixer, and stir slowly at 100 - 135 r / min for 3 - 5 min until evenly mixed to obtain dry materials.

[0062] S3. Add water to the dry materials in S2 and continue to stir slowly for 2 - 3 min. After the dry materials are liquefied, add a thickening agent and stir evenly to obtain a mixture.

[0063] S4. Slowly add the polyethylene fiber to the mixture in S3, and stir quickly at 185 - 230 r / min for 2 - 3 min until the polyethylene fiber is evenly dispersed to obtain a slurry.

[0064] S5. Pour the slurry in S4 into a mold, seal it after vibrating and forming, cure it at room temperature for 28 days after demolding to obtain concrete.

[0065] Test Example 1 Conduct mechanical property tests on the ultra-high ductility lithium slag concrete in Examples 1 - 3 and the concrete in Comparative Examples 1 - 3. The results are shown in Table 1.

[0066] Table 1. Mechanical property data table of Examples 1 - 3 and Comparative Examples 1 - 3

[0067] As can be seen from Table 1, the ultra-high ductility lithium slag concrete in Example 1 has good deformation ability, showing excellent steady-state cracking behavior and ductility ability. The ultra-high ductility lithium slag concrete in Example 2 shows good strain-hardening characteristics and ductility ability, and the ultra-high ductility lithium slag concrete in Example 3 shows excellent tensile ductility and crack control ability.

[0068] However, for the concrete in Comparative Example 1, adding no lithium slag powder and a small amount of polyethylene fiber has limited improvement in concrete performance, brittle fracture occurs, and the ductility and crack resistance of the concrete are poor. For the concrete in Comparative Example 2, the lithium slag powder that has not been physically and chemically activated cannot fully exert its potential activity, and no polyethylene fiber is added, brittle failure occurs, no multi-cracks are formed, and the performance is significantly lower than that of Examples 1 - 3 of the present invention. For the concrete in Comparative Example 3, adding too much polyethylene fiber will make it too viscous during mixing and construction, and the polyethylene fiber fails to be evenly dispersed and fails to achieve steady-state cracking.

[0069] Therefore, the present invention adopts a super high ductility lithium slag concrete with the above components and its preparation method. Through the activation of the activity of lithium slag and the optimization of its dosage, combined with the filling effect of fly ash and the humidity adjustment function of water-absorbing polymers, and introducing polyethylene fibers to achieve the large deformation and multi-crack cracking ability of lithium slag concrete, the obtained super high ductility lithium slag concrete has high ductility and strain hardening characteristics. It not only realizes the resource utilization of modified lithium slag powder, overcomes the brittle defect of lithium slag concrete, but also has significant advantages such as environmental friendliness, low cost, and high performance, and is applicable to a variety of building and engineering application scenarios.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An ultra-high ductility lithium slag concrete, characterized in that: The components, calculated by weight, include 390-450 parts of cement, 40-120 parts of modified lithium slag powder, 500-700 parts of fly ash, 300-500 parts of quartz sand, 10-20 parts of polyethylene fiber, 30-40 parts of water-absorbing polymer, 3-6 parts of high-efficiency water reducing agent, 1-3 parts of thickener and 330-460 parts of water.

2. The ultra-high ductility lithium slag concrete according to claim 1, characterized in that: The length of polyethylene fibers is 12-24 mm and the diameter is 20-30 μm.

3. The ultra-high ductility lithium slag concrete according to claim 1, characterized in that: The water-absorbing polymer is a polyacrylic acid-acrylamide type high molecular water-absorbing resin with a particle size of 150-620 μm.

4. The ultra-high ductility lithium slag concrete according to claim 1, characterized in that: The particle size of quartz sand is 0.2-0.6mm, the fineness modulus is 2.5-3.0, and the mud content is less than 1%.

5. The ultra-high ductility lithium slag concrete according to claim 1, characterized in that: The particle size of fly ash is 50-400μm and the specific surface area is 400-600m 2 / kg.

6. The ultra-high ductility lithium slag concrete according to claim 1, characterized in that: The thickener is cellulose ether, and the added amount of the thickener is 0.03-0.05% of the total mass of the ultra-high ductility lithium slag concrete.

7. A method for preparing ultra-high ductility lithium slag concrete according to any one of claims 1 to 6, characterized in that: The following steps are included: S1. Weigh 390-450 parts of cement, 40-120 parts of modified lithium slag powder, 500-700 parts of fly ash, 300-500 parts of quartz sand, 10-20 parts of polyethylene fiber, 30-40 parts of water-absorbing polymer, 3-6 parts of high-efficiency water reducing agent, 1-3 parts of thickener and 330-460 parts of water by mass; S2, adding cement, modified lithium slag powder, quartz sand, fly ash and high-efficiency water reducing agent into a mixer, stirring slowly for 3-5 minutes until the mixture is evenly mixed to obtain dry material; S3, add water to the dry material in S1 and continue to stir slowly for 2-3 minutes, add thickener after the dry material is liquefied, and stir evenly to obtain a mixture; S4, slowly add polyethylene fiber to the mixture in S3, and stir rapidly for 2-3 minutes until the polyethylene fiber is evenly dispersed to obtain slurry; S5. Pour the slurry in S4 into a mold, vibrate it into shape and then seal it. After demoulding, cure it at room temperature for 28 days to obtain ultra-high ductility lithium slag concrete.

8. The method for preparing ultra-high ductility lithium slag concrete according to claim 7, characterized in that: In S1, the preparation steps of the modified lithium slag powder are as follows: the waste lithium slag is recovered and then crushed, finely ground, washed and dried in sequence; the dried lithium slag powder is mixed with an alkaline activator and then soaked; after complete reaction, the powder is sieved to obtain the modified lithium slag powder.

9. The method for preparing ultra-high ductility lithium slag concrete according to claim 7, characterized in that: In S2 and S3, the speed of slow stirring is 100-135 r / min.

10. The method for preparing ultra-high ductility lithium slag concrete according to claim 7, characterized in that: In S4, the rotation speed of rapid stirring is 185-230r / min.

Images