UHPC light-weight board prepared based on limestone machine-made sand and preparation method of UHPC light-weight board

Abstract

The invention provides a UHPC light-weight plate prepared based on limestone machine-made sand and a preparation method of the UHPC light-weight plate. The UHPC light-weight board is prepared from the following raw materials in parts by weight: 22 to 27 parts of ceramsite, 12 to 15 parts of steel fiber, 420 to 460 parts of ordinary cement, 40 to 50 parts of modified silicon-manganese slag, 15 to 27 parts of modified phosphorus slag powder, 50 to 70 parts of limestone particles, 10 to 18 parts of steel slag, 20 to 40 parts of fly ash, 40 to 60 parts of mineral powder, 400 to 420 parts of limestone machine-made sand, 6 to 10 parts of polycarboxylate superplasticizer, 0.2 to 0.4 part of hydroxyethyl methyl cellulose and 150 to 170 parts of water. The UHPC light-weight plate prepared based on the limestone machine-made sand is excellent in mechanical property, good in temperature resistance and high in impact resistance and has wide market prospects and application value.

Description

Technical Field

[0001] The invention belongs to the technical field of construction, and particularly relates to a UHPC lightweight plate prepared based on limestone machine-made sand and a preparation method thereof. Background Art

[0002] UHPC, or Ultra-High Performance Concrete, is a new type of high-performance building material. With its excellent mechanical properties and durability, it has been widely used in engineering fields such as construction, bridges, and roads. As an important application form of UHPC, UHPC panels have many advantages such as light weight, high strength, durability, fire resistance, and heat insulation.

[0003] When using UHPC panels in areas with large temperature differences, some specific technical problems will be encountered, which will affect the performance of the material: (1) Temperature stress: In an environment with large temperature differences, UHPC panels may experience large temperature changes, resulting in temperature stress. Excessive temperature stress may cause microcracks inside the material, which in turn affects the integrity and durability of the overall structure. (2) Thermal expansion and contraction: UHPC is also affected by thermal expansion and contraction, especially in areas with large temperature differences between day and night or obvious seasonal changes. If the design and construction are not appropriate, this physical change may cause structural deformation or cracking. (3) Shrinkage cracks: UHPC will experience a certain degree of shrinkage during the hardening process, and in an environment with large temperature differences, this shrinkage effect may be amplified, resulting in cracks on the surface or inside the panel.

[0004] The existing technology is to improve the temperature difference resistance of UHPC by adjusting its formula, such as increasing the fiber content or using special additives to improve the crack resistance. However, increasing the fiber content will lead to a decrease in the strength of the board and cannot meet the needs of the existing market.

[0005] Therefore, there is an urgent need for a UHPC lightweight plate with good temperature resistance and high mechanical strength. Summary of the invention

[0006] The purpose of the present invention is to provide a UHPC lightweight plate prepared based on limestone machine-made sand and a preparation method thereof. Ceramsite is added as an internal curing component to provide moisture for the internal hydration of UHPC, improve the hydration rate and hardened body strength, and reduce early cracks and self-shrinkage.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A UHPC lightweight plate prepared based on limestone machine-made sand comprises the following raw materials in parts by weight: 22-27 parts of ceramsite, 12-15 parts of steel fiber, 420-460 parts of ordinary cement, 40-50 parts of modified silicon manganese slag, 15-27 parts of modified phosphorus slag powder, 50-70 parts of limestone particles, 10-18 parts of steel slag, 20-40 parts of fly ash, 40-60 parts of mineral powder, 400-420 parts of limestone machine-made sand, 6-10 parts of polycarboxylate water reducer, 0.2-0.4 parts of hydroxyethyl methylcellulose and 150-170 parts of water.

[0009] Furthermore, the preparation method of the modified silicomanganese slag includes: uniformly mixing 100 parts by weight of silicomanganese slag powder, 0.2-0.4 parts by weight of tartrate, and 0.1-0.3 parts by weight of sodium p-aminobenzenesulfonate to obtain modified silicomanganese slag powder.

[0010] Furthermore, the preparation method of the modified phosphorus slag powder includes: uniformly mixing 100 parts by weight of phosphorus slag powder, 0.3-0.6 parts by weight of quaternary ammonium salt cationic starch and 0.2-0.4 parts by weight of sodium citrate to obtain the modified phosphorus slag powder.

[0011] The preparation method of the ceramsite comprises the following steps:

[0012] (1) preparing materials by crushing, grinding and screening the coal gangue to obtain coal gangue powder with a particle size of 0.1-0.15 mm;

[0013] (2) Mixing: weighing raw materials according to the following weight ratio: 12-15% clay powder, 7-12% shale powder, 2-5% mineral powder, and the balance coal gangue powder; uniformly mixing the raw materials to obtain a mixed powder, adding 20-24% of deionized water in an amount of the total weight of the mixed powder to the mixed powder, stirring, and standing to obtain a mixed material;

[0014] (3) granulation, extruding the mixed material into strips, and then drying, crushing and passing through a 100-mesh sieve to obtain dry granules;

[0015] (4) Calcination: calcining the dried particles at 1050-1100° C. for 35-40 min, and naturally cooling to room temperature to obtain ceramsite.

[0016] The present invention attempts to add phosphorus slag powder and manganese silicon manganese slag to improve the compressive strength of the plate, but the effect is not ideal, mainly because the active substances therein cannot be well stimulated in the system, resulting in poor results. The present invention can improve the compressive strength of the plate by modifying the two substances respectively, and can play a chemical excitation role by modifying the organic salt, which can improve the working performance of the concrete mixture and adjust the state of the concrete mixture. Chloride ions penetrate into the interior of the plate and can corrode the internal structure of the plate, affecting the durability of the material, so the chloride ion permeability resistance of the plate is particularly important. Adding a specific amount of modified silicon manganese slag and modified phosphorus slag powder in the system of the present invention can improve the chloride ion penetration resistance of the plate. Analysis shows that under this condition, the structural density of the plate can be increased, the overall electrical flux is low, the chloride ion penetration resistance is good, and the product durability is good. However, after adding modified silicon manganese slag and modified phosphorus slag powder, the temperature resistance of the plate is not ideal, especially cracking is prone to occur under impact resistance conditions.

[0017] Furthermore, the ordinary cement is a mixture of P.O42.5 ordinary Portland cement and P.O52.5 ordinary Portland cement in a weight ratio of (2-4):1.

[0018] Furthermore, the preparation method of the polycarboxylate water-reducing agent comprises:

[0019] (1) 70-80 parts by weight of microcrystalline cellulose and 20-30 parts by weight of an unsaturated monomer are mixed, treated with microwave assistance, 1-3 parts by weight of p-toluenesulfonic acid and 0.03-0.05 parts by weight of hydroquinone are added, and the mixture is stirred and heated to 80-100° C. for reaction for 5-8 hours to obtain a first monomer;

[0020] (2) adding 30-40 parts by weight of silane coupling agent KH550 dropwise to 60-70 parts by weight of unsaturated carboxylic acid, adding 1-3 parts by weight of p-toluenesulfonic acid and 0.03-0.05 parts by weight of hydroquinone, and reacting at 60-70° C. for 2-3 hours to obtain a second monomer;

[0021] (3) 30-40 parts by weight of the first monomer, 60-70 parts by weight of the second monomer and 200-250 parts by weight of water are mixed, heated to 60-80° C., and 15-20 parts by weight of maleic anhydride, 1-2 parts by weight of ammonium persulfate and 1-2 parts by weight of isopropanol are added dropwise in sequence within 1-2 hours. After reacting for 2-7 hours, heating is stopped to obtain a copolymer product;

[0022] (4) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5-5.5, and adding water to dilute the copolymer product to a mass fraction of 22-26%, thereby obtaining a polycarboxylic acid water reducer.

[0023] Microcrystalline cellulose was purchased from Hunan Yunbang Biotechnology Co., Ltd., product number: YM59139.

[0024] Furthermore, the unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1: (1.3-1.7): (0.2-0.5).

[0025] Furthermore, the unsaturated carboxylic acid is methacrylic acid, acrylic acid and maleic acid in a weight ratio of (1.6-1.8):1:(0.4-0.7).

[0026] The present invention uses commercially available polycarboxylate water-reducing agents to improve the heat resistance of the board, which is not ideal. The polycarboxylate water-reducing agent prepared by the present invention can effectively improve the heat resistance of the board, especially improve the impact resistance of the board after changing temperature conditions. The polycarboxylate water-reducing agent of the present invention contains a cellulose group, and the microcrystalline cellulose group can help improve the microstructure of the concrete and reduce the porosity. This helps to improve the density of the concrete. The microcrystalline cellulose group can improve the interface bonding between the components inside the concrete, thereby improving the integrity of the concrete; and modified with a silane coupling agent KH550, by improving the interface bonding, the occurrence of microcracks in the interface area caused by temperature changes can be reduced, thereby improving the impact resistance of the concrete. The present invention uses unsaturated monomers and unsaturated carboxylic acids in a specific ratio and composition, so that the polycarboxylate water-reducing agent has a unique network structure, which can promote the close arrangement of particles inside the concrete, improve the overall density of the concrete, and further enhance its ability to resist temperature changes. At the same time, the flexural strength of the board can be improved.

[0027] Furthermore, hydroxyethyl methylcellulose is EASONZELL TM ME4000. Purchased from Zhejiang Yisheng New Materials Co., Ltd.

[0028] Furthermore, the limestone machine-made sand includes 20-40 mesh limestone machine-made sand, 40-70 mesh limestone machine-made sand and 100-130 mesh limestone machine-made sand in a weight ratio of 1:3-4:0.2-0.5.

[0029] Furthermore, the specific surface area of ​​the mineral powder is 680-770m 2 / kg.

[0030] The present invention also provides a method for preparing a UHPC lightweight plate based on limestone machine-made sand, the preparation method comprising the following steps:

[0031] (1) Weigh the raw materials according to the weight ratio, mix them evenly, inject them into the mold and vibrate them into shape;

[0032] (2) Place the formed sheet in a flat static area for 4-6 hours for initial setting. The temperature of the initial curing room is 20°C and the relative humidity is 65-75%;

[0033] (3) After the initial curing, the mold is removed and the room is moved to the final curing room for steam curing. The temperature of the final curing room is controlled at 75-85°C and the curing time is 45-55h;

[0034] (4) After the final curing is completed, the plate is removed from the final curing room and watered for 17-20 days to obtain a UHPC lightweight plate made from limestone machine-made sand.

[0035] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0036] 1. The present invention can improve the compressive strength of the board by modifying the two substances, silicon manganese slag and phosphorus slag powder, respectively. The modification by organic salt can play a chemical excitation role, improve the working performance of the concrete mixture, and adjust the state of the concrete mixture. The present invention uses ceramsite to replace part of the aggregate as the internal curing aggregate. First, the internal curing aggregate can store water, and continuously release water to cement hydration during the curing stage, thereby promoting the degree of cement hydration and improving the strength of the substrate; second, ceramsite is a light aggregate, and a lightweight board with a lighter density can be prepared.

[0037] 2. Adding a specific amount of modified silicon-manganese slag and modified phosphorus slag powder to the system of the present invention can improve the plate's resistance to chloride ion penetration.

[0038] 3. The polycarboxylate water-reducing agent prepared by the present invention can effectively improve the temperature resistance of the board, especially improve the impact resistance of the board under temperature change conditions, and can also improve the flexural strength of the board. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The raw materials used in the present invention are purchased from the following manufacturers:

[0041] Silicon manganese slag powder, Qinghe County Xingxin New Material Technology Co., Ltd., 300-500 mesh.

[0042] Phosphorus slag, Shijiazhuang Yuanjing Mineral Products Co., Ltd., 500-1000 mesh.

[0043] Limestone particles, Guangxi Runhan New Material Technology Co., Ltd., 1000-2000 mesh.

[0044] Steel slag, Guangxi Yuansheng Slag Comprehensive Utilization Co., Ltd., 500-2000 mesh.

[0045] Fly ash, Guangxi Qinzhou Landao Environmental Protection Materials Co., Ltd., 200-600 mesh.

[0046] Mineral powder, Guangxi Yuansheng Slag Comprehensive Utilization Co., Ltd., S95 mineral powder.

[0047] Steel fiber, Shandong Hongshuo New Materials Co., Ltd., shear type steel fiber.

[0048] Limestone machine-made sand, Guangxi Runhan New Material Technology Co., Ltd., fineness modulus 2.4-2.9.

[0049] Clay powder: calcined kaolin clay powder, Lingshou County Anda Mineral Powder Factory, average particle size 1250 mesh.

[0050] Example 1

[0051] The present embodiment provides a UHPC lightweight plate prepared based on limestone machine-made sand, including the following raw materials in parts by weight: 24 parts of ceramsite, 13 parts of steel fiber, 440 parts of ordinary cement, 45 parts of modified silicon manganese slag, 21 parts of modified phosphorus slag powder, 60 parts of limestone particles, 15 parts of steel slag, 27 parts of fly ash, 49 parts of mineral powder, 410 parts of limestone machine-made sand, 8 parts of polycarboxylate water reducer, 0.3 parts of hydroxyethyl methylcellulose, and 160 parts of water.

[0052] The preparation method of the modified silicomanganese slag comprises: uniformly mixing 100 parts by weight of silicomanganese slag powder, 0.3 parts by weight of tartrate and 0.2 parts by weight of sodium p-aminobenzenesulfonate to obtain the modified silicomanganese slag powder.

[0053] The preparation method of the modified phosphorus slag powder comprises: uniformly mixing 100 parts by weight of phosphorus slag powder, 0.5 parts by weight of quaternary ammonium salt type cationic starch and 0.3 parts by weight of sodium citrate to obtain the modified phosphorus slag powder.

[0054] The preparation method of the ceramsite comprises the following steps:

[0055] (1) preparing materials by crushing, grinding and screening the coal gangue to obtain coal gangue powder with a particle size of 0.1-0.15 mm;

[0056] (2) Mixing: weighing raw materials according to the following weight ratio: 13% clay powder, 9% shale powder, 4% mineral powder, and the balance coal gangue powder; uniformly mixing the raw materials to obtain a mixed powder, adding 22% of deionized water to the mixed powder, which is based on the total weight of the mixed powder, stirring, and standing to obtain a mixed material;

[0057] (3) granulation, extruding the mixed material into strips, and then drying, crushing and passing through a 100-mesh sieve to obtain dry granules;

[0058] (4) Calcination: calcining the dried particles at 1060° C. for 38 min and cooling them naturally to room temperature to obtain ceramsite.

[0059] The ordinary cement is a mixture of P.O42.5 ordinary Portland cement and P.O52.5 ordinary Portland cement in a weight ratio of 3:1.

[0060] The preparation method of the polycarboxylate water reducer comprises:

[0061] (1) 75 parts by weight of microcrystalline cellulose and 25 parts by weight of unsaturated monomers are mixed, treated with microwave assistance, 2 parts by weight of p-toluenesulfonic acid and 0.04 parts by weight of hydroquinone are added, and the mixture is stirred and heated to 90° C. for reaction for 6 hours to obtain a first monomer; the unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1:1.5:0.4.

[0062] (2) 35 parts by weight of silane coupling agent KH550 was added dropwise to 66 parts by weight of unsaturated carboxylic acid, 2 parts by weight of p-toluenesulfonic acid and 0.04 parts by weight of hydroquinone were added, and the mixture was reacted at 65° C. for 2.5 hours to obtain a second monomer; the unsaturated carboxylic acid was methacrylic acid, acrylic acid and maleic acid in a weight ratio of 1.7:1:0.6.

[0063] (3) 35 parts by weight of the first monomer, 65 parts by weight of the second monomer and 230 parts by weight of water were mixed and heated to 70° C., and 17 parts by weight of maleic anhydride, 1.5 parts by weight of ammonium persulfate and 1.6 parts by weight of isopropanol were added dropwise in sequence over 1.6 hours. After reacting for 5 hours, heating was stopped to obtain a copolymer product;

[0064] (4) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5.2, and adding water to dilute the copolymer product to a mass fraction of 24%, thereby obtaining a polycarboxylic acid water reducer.

[0065] Microcrystalline cellulose was purchased from Hunan Yunbang Biotechnology Co., Ltd., product number: YM59139.

[0066] Hydroxyethyl methylcellulose is EASONZELL TM ME4000. Purchased from Zhejiang Yisheng New Materials Co., Ltd.

[0067] The limestone machine-made sand includes 20-40 mesh limestone machine-made sand, 40-70 mesh limestone machine-made sand and 100-130 mesh limestone machine-made sand in a weight ratio of 1:3.2:0.3.

[0068] The specific surface area of ​​mineral powder is 680-770m 2 / kg.

[0069] The method for preparing a UHPC lightweight plate based on limestone machine-made sand comprises the following steps:

[0070] (1) Weigh the raw materials according to the weight ratio, mix them evenly, inject them into the mold and vibrate them into shape;

[0071] (2) Place the formed sheet in a flat static area for 5 hours to cure for initial setting. The temperature in the initial curing room is controlled at 20°C and the relative humidity is 70%;

[0072] (3) After the initial curing, the mold is removed and the room is moved to the final curing room for steam curing. The temperature of the final curing room is controlled at 80°C and the curing time is 48 hours;

[0073] (4) After the final curing, the panels were moved out of the final curing room and watered for 18 days to obtain UHPC lightweight panels made from limestone machine-made sand.

[0074] Example 2

[0075] The present embodiment provides a UHPC lightweight plate prepared based on limestone machine-made sand, including the following raw materials in parts by weight: 22 parts of ceramsite, 15 parts of steel fiber, 420 parts of ordinary cement, 40 parts of modified silicon manganese slag, 15 parts of modified phosphorus slag powder, 50 parts of limestone particles, 10 parts of steel slag, 20 parts of fly ash, 40 parts of mineral powder, 400 parts of limestone machine-made sand, 6 parts of polycarboxylate water reducer, 0.2 parts of hydroxyethyl methylcellulose, and 150 parts of water.

[0076] The preparation method of the modified silicomanganese slag comprises: uniformly mixing 100 parts by weight of silicomanganese slag powder, 0.2 parts by weight of tartrate and 0.1 parts by weight of sodium p-aminobenzenesulfonate to obtain the modified silicomanganese slag powder.

[0077] The preparation method of the modified phosphorus slag powder comprises: uniformly mixing 100 parts by weight of phosphorus slag powder, 0.3 parts by weight of quaternary ammonium salt type cationic starch and 0.2 parts by weight of sodium citrate to obtain the modified phosphorus slag powder.

[0078] The preparation method of the ceramsite comprises the following steps:

[0079] (1) preparing materials by crushing, grinding and screening the coal gangue to obtain coal gangue powder with a particle size of 0.1-0.15 mm;

[0080] (2) Mixing: weighing raw materials according to the following weight ratio: 12% clay powder, 12% shale powder, 2% mineral powder, and the balance coal gangue powder; uniformly mixing the raw materials to obtain a mixed powder, adding 24% of deionized water to the mixed powder, which is based on the total weight of the mixed powder, stirring, and standing to obtain a mixed material;

[0081] (3) granulation, extruding the mixed material into strips, and then drying, crushing and passing through a 100-mesh sieve to obtain dry granules;

[0082] (4) Calcination: calcining the dried particles at 1100° C. for 35 min and cooling them naturally to room temperature to obtain ceramsite.

[0083] The ordinary cement is a mixture of P.O42.5 ordinary Portland cement and P.O52.5 ordinary Portland cement in a weight ratio of 2:1.

[0084] The preparation method of the polycarboxylate water reducer comprises:

[0085] (1) 70 parts by weight of microcrystalline cellulose and 20 parts by weight of unsaturated monomers are mixed, treated with microwave assistance, 1 part by weight of p-toluenesulfonic acid and 0.03 parts by weight of hydroquinone are added, and the mixture is stirred and heated to 80° C. for reaction for 5 hours to obtain a first monomer; the unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1:1.3:0.2.

[0086] (2) 30 parts by weight of silane coupling agent KH550 was added dropwise to 60 parts by weight of unsaturated carboxylic acid, 1 part by weight of p-toluenesulfonic acid and 0.03 parts by weight of hydroquinone were added, and the mixture was reacted at 60° C. for 2 h to obtain a second monomer; the unsaturated carboxylic acid was methacrylic acid, acrylic acid and maleic acid in a weight ratio of 1.6:1:0.4.

[0087] (3) 30 parts by weight of the first monomer, 60 parts by weight of the second monomer and 200 parts by weight of water were mixed and heated to 60° C., and 15 parts by weight of maleic anhydride, 1 part by weight of ammonium persulfate and 1 part by weight of isopropanol were added dropwise in sequence within 1 hour. After reacting for 2 hours, heating was stopped to obtain a copolymer product;

[0088] (4) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5, and adding water to dilute the copolymer product to a mass fraction of 22%, thereby obtaining a polycarboxylic acid water reducer.

[0089] Microcrystalline cellulose was purchased from Hunan Yunbang Biotechnology Co., Ltd., product number: YM59139.

[0090] Hydroxyethyl methylcellulose is EASONZELL TM ME4000. Purchased from Zhejiang Yisheng New Materials Co., Ltd.

[0091] The limestone machine-made sand includes 20-40 mesh limestone machine-made sand, 40-70 mesh limestone machine-made sand and 100-130 mesh limestone machine-made sand in a weight ratio of 1:3:0.2.

[0092] The specific surface area of ​​mineral powder is 680-770m 2 / kg.

[0093] The method for preparing a UHPC lightweight plate based on limestone machine-made sand comprises the following steps:

[0094] (1) Weigh the raw materials according to the weight ratio, mix them evenly, inject them into the mold and vibrate them into shape;

[0095] (2) Place the formed sheet in a flat static area for 4 hours to cure for initial setting. The temperature in the initial curing room is controlled at 20°C and the relative humidity is 70%;

[0096] (3) After the initial curing, the mold is removed and the room is moved to the final curing room for steam curing. The temperature of the final curing room is controlled at 80°C and the curing time is 48 hours;

[0097] (4) After the final curing, the panels were moved out of the final curing room and watered for 17 days to obtain UHPC lightweight panels made from limestone machine-made sand.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 1 is: 21 parts of modified silicon manganese slag and 45 parts of modified phosphorus slag powder.

[0100] Comparative Example 2

[0101] The difference between this comparative example and Example 1 is: 57 parts of fly ash, 69 parts of mineral powder, and 360 parts of limestone machine-made sand.

[0102] Comparative Example 3

[0103] The difference between this comparative example and Example 1 is that the unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1:1:1. The unsaturated carboxylic acid is methacrylic acid, acrylic acid and maleic acid in a weight ratio of 1:1:1.

[0104] Comparative Example 4

[0105] The difference between this comparative example and Example 1 is that the preparation method of the polycarboxylate water-reducing agent comprises:

[0106] (1) 75 parts by weight of microcrystalline cellulose and 25 parts by weight of unsaturated monomers are mixed, treated with microwave assistance, 2 parts by weight of p-toluenesulfonic acid and 0.04 parts by weight of hydroquinone are added, and the mixture is stirred and heated to 90° C. for reaction for 6 hours to obtain a first monomer; the unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1:1.5:0.4.

[0107] (2) 100 parts by weight of the first monomer and 230 parts by weight of water were mixed, heated to 70° C., and 17 parts by weight of maleic anhydride, 1.5 parts by weight of ammonium persulfate and 1.6 parts by weight of isopropanol were added dropwise in sequence over 1.6 hours. After reacting for 5 hours, heating was stopped to obtain a copolymer product;

[0108] (3) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5.2, and adding water to dilute the copolymer product to a mass fraction of 24%, thereby obtaining a polycarboxylic acid water reducer.

[0109] Comparative Example 5

[0110] The difference between this comparative example and Example 1 is that the preparation method of the polycarboxylate water-reducing agent comprises:

[0111] (1) 35 parts by weight of silane coupling agent KH550 are added dropwise to 66 parts by weight of unsaturated carboxylic acid, 2 parts by weight of p-toluenesulfonic acid and 0.04 parts by weight of hydroquinone are added, and the mixture is reacted at 65° C. for 2.5 hours to obtain a first monomer; the unsaturated carboxylic acid is methacrylic acid, acrylic acid and maleic acid in a weight ratio of 1.7:1:0.6.

[0112] (2) 100 parts by weight of the first monomer and 230 parts by weight of water were mixed, heated to 70° C., and 17 parts by weight of maleic anhydride, 1.5 parts by weight of ammonium persulfate and 1.6 parts by weight of isopropanol were added dropwise in sequence over 1.6 hours. After reacting for 5 hours, heating was stopped to obtain a copolymer product;

[0113] (3) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5.2, and adding water to dilute the copolymer product to a mass fraction of 24%, thereby obtaining a polycarboxylic acid water reducer.

[0114] Comparative Example 6

[0115] The difference between this comparative example and Example 1 is that the polycarboxylate water reducer is a commercially available product purchased from Henan Mingzhixin Chemical Products Co., Ltd.

[0116] Performance Testing

[0117] The performance of the UHPC lightweight panels prepared based on limestone machine-made sand prepared in Examples 1-2 and Comparative Examples 1-6 was tested.

[0118] 1. Refer to GB / T31387-2015 to test compressive strength and flexural strength;

[0119] 2. Conduct impact resistance test according to GBT17657-2013: (1) Conduct the test at room temperature and observe whether cracks appear on the surface of the specimen. (2) Place the plate at -10℃, 25℃ and 40℃ for 10 days in sequence as a cycle. After three cycles, conduct impact resistance test and observe whether cracks appear on the surface of the specimen.

[0120] 3. Durability: Refer to GB / T50082-2009 for chloride ion flux test and chloride ion penetration resistance study.

[0121] The test results are shown in Table 1.

[0122] Table 1 Performance test results

[0123]

[0124]

[0125] It can be seen from the above performance test results that the comprehensive performance of Examples 1-2 is better, especially the comprehensive performance of Example 1 is the most outstanding, which is mainly due to the synergistic effect between the components.

[0126] However, the comparative examples are significantly inferior to the embodiments in the corresponding performance tests because they do not adopt the necessary technical solutions. In comparative example 1, the addition amount of modified silicon manganese slag and modified phosphorus slag powder is changed, and the compressive strength and chloride ion penetration resistance of the plate are reduced. In comparative example 2, the addition amount of fly ash, mineral powder, and limestone machine-made sand is changed, and the chloride ion penetration resistance of the plate is reduced, indicating that the raw material composition of the plate has an impact on the chloride ion penetration resistance. The preparation scheme of the polycarboxylate water-reducing agent in comparative examples 3-5 is changed, and the temperature resistance and flexural strength of the plate are reduced. Comparative example 6 uses a commercially available polycarboxylate water-reducing agent, and the overall comprehensive performance of the product is inferior to that of the product prepared in Examples 1-2. The above experimental results further demonstrate the importance of the technical solution defined in the present invention for its technical effect.

[0127] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A UHPC lightweight plate prepared based on limestone machine-made sand, characterized in that: The invention comprises the following raw materials in parts by weight: 22-27 parts of ceramsite, 12-15 parts of steel fiber, 420-460 parts of ordinary cement, 40-50 parts of modified silicon manganese slag, 15-27 parts of modified phosphorus slag powder, 50-70 parts of limestone particles, 10-18 parts of steel slag, 20-40 parts of fly ash, 40-60 parts of mineral powder, 400-420 parts of limestone machine-made sand, 6-10 parts of polycarboxylate water reducer, 0.2-0.4 parts of hydroxyethyl methyl cellulose and 150-170 parts of water; The preparation method of the modified silicomanganese slag comprises: uniformly mixing 100 parts by weight of silicomanganese slag powder, 0.2-0.4 parts by weight of tartrate and 0.1-0.3 parts by weight of sodium p-aminobenzenesulfonate to obtain the modified silicomanganese slag powder. The preparation method of the ceramsite comprises the following steps: (1) preparing materials by crushing, grinding and screening the coal gangue to obtain coal gangue powder with a particle size of 0.1-0.15 mm; (2) Mixing: weighing raw materials according to the following weight ratio: 12-15% clay powder, 7-12% shale powder, 2-5% mineral powder, and the balance coal gangue powder; uniformly mixing the raw materials to obtain a mixed powder, adding 20-24% of deionized water in an amount of the total weight of the mixed powder to the mixed powder, stirring, and standing to obtain a mixed material; (3) granulation, extruding the mixed material into strips, and then drying, crushing and passing through a 100-mesh sieve to obtain dry granules; (4) Calcination: calcining the dried particles at 1050-1100° C. for 35-40 min, and naturally cooling to room temperature to obtain ceramsite.

2. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1 is characterized in that: The preparation method of the modified phosphorus slag powder comprises: uniformly mixing 100 parts by weight of phosphorus slag powder, 0.3-0.6 parts by weight of quaternary ammonium salt type cationic starch and 0.2-0.4 parts by weight of sodium citrate to obtain the modified phosphorus slag powder.

3. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1, characterized in that: The ordinary cement is a mixture of P.O42.5 ordinary Portland cement and P.O52.5 ordinary Portland cement in a weight ratio of (2-4):

1.

4. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1, characterized in that: The preparation method of the polycarboxylate water reducer comprises: (1) 70-80 parts by weight of microcrystalline cellulose and 20-30 parts by weight of an unsaturated monomer are mixed, treated with microwave assistance, 1-3 parts by weight of p-toluenesulfonic acid and 0.03-0.05 parts by weight of hydroquinone are added, and the mixture is stirred and heated to 80-100° C. for reaction for 5-8 hours to obtain a first monomer; (2) adding 30-40 parts by weight of silane coupling agent KH550 dropwise to 60-70 parts by weight of unsaturated carboxylic acid, adding 1-3 parts by weight of p-toluenesulfonic acid and 0.03-0.05 parts by weight of hydroquinone, and reacting at 60-70° C. for 2-3 hours to obtain a second monomer; (3) 30-40 parts by weight of the first monomer, 60-70 parts by weight of the second monomer and 200-250 parts by weight of water are mixed, heated to 60-80° C., and 15-20 parts by weight of maleic anhydride, 1-2 parts by weight of ammonium persulfate and 1-2 parts by weight of isopropanol are added dropwise in sequence within 1-2 hours. After reacting for 2-7 hours, heating is stopped to obtain a copolymer product; (4) adding sodium hydroxide solution to the copolymer product to adjust the pH to 5-5.5, and adding water to dilute the copolymer product to a mass fraction of 22-26%, thereby obtaining a polycarboxylic acid water reducer.

5. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 4 is characterized in that: The unsaturated monomer is a mixture of methacrylic acid, acrylic acid and maleic anhydride in a weight ratio of 1: (1.3-1.7): (0.2-0.5).

6. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 4, characterized in that: The unsaturated carboxylic acid is methacrylic acid, acrylic acid and maleic acid in a weight ratio of (1.6-1.8):1:(0.4-0.7).

7. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1, characterized in that: Hydroxyethyl methylcellulose is EASONZELL TM ME4000.

8. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1, characterized in that: The limestone machine-made sand includes 20-40 mesh limestone machine-made sand, 40-70 mesh limestone machine-made sand and 100-130 mesh limestone machine-made sand in a weight ratio of 1:3-4:0.2-0.

5.

9. The UHPC lightweight plate prepared based on limestone machine-made sand according to claim 1, characterized in that: The specific surface area of ​​mineral powder is 680-770m 2 / kg.

10. A method for preparing a UHPC lightweight plate based on limestone machine-made sand according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) Weigh the raw materials according to the weight ratio, mix them evenly, inject them into the mold and vibrate them into shape; (2) Place the formed sheet in a flat static area for 4-6 hours for initial setting. The temperature in the initial curing room is controlled at 18-25°C and the relative humidity is 65-75%; (3) After the initial curing, the mold is removed and the room is moved to the final curing room for steam curing. The temperature of the final curing room is controlled at 75-85°C and the curing time is 45-55h; (4) After the final curing is completed, the plate is removed from the final curing room and watered for 17-20 days to obtain a UHPC lightweight plate made from limestone machine-made sand.

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