Modified solid waste self-compacting low-carbon concrete and preparation method thereof

Abstract

The application relates to the technical field of building materials, in particular to a modified solid waste self-compacting low-carbon concrete and a preparation method thereof. The self-compacting low-carbon concrete comprises the following raw material components: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water and polycarboxylic acid high-performance water reducing agent; the modified solid waste slurry is obtained by sequentially mixing and treating solid waste mixed powder with water and modifying the solid waste mixed powder with a modifier; and the modified solid waste aggregate is obtained by sequentially soaking solid waste mixed aggregate in a low-concentration hydrochloric acid solution, modifying the soaked solid waste mixed aggregate with an interface reinforcing agent and drying the modified solid waste mixed aggregate. According to the application, the solid waste is modified and optimized, the solid waste self-compacting concrete mixing ratio is optimized, and a special additive for the solid waste self-compacting low-carbon concrete is configured, so that the solid waste can stably play a role in the concrete, the mechanical properties and the durability of the concrete are improved, the rheological properties of the concrete can meet the requirements of the self-compacting concrete, and the waste utilization can achieve a low-carbon effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a modified solid waste self-compacting low-carbon concrete and a preparation method thereof. BACKGROUND

[0002] Concrete is one of the core basic materials for building a large country, and is the most widely used and largest man-made material in the national economy. The carbon emission of concrete mainly comes from cement, which accounts for a high proportion in cementitious materials, has a large amount of use, and has a high carbon emission. The most important problem in the world at present is to cope with climate change.

[0003] At present, the low carbonization of concrete mainly focuses on the reuse of solid waste materials. By introducing solid waste materials, natural materials such as cement, sand and gravel are replaced to reduce carbon emissions. However, in the process of use, due to the complex composition of solid waste, the performance of solid waste concrete is difficult to control stably, and most solid waste concrete is only applied to non-structural parts and ordinary concrete, and is less used in special concrete, especially self-compacting concrete.

[0004] To solve the above problems, by adding solid waste powder to replace part of the cement, solid waste aggregate to replace natural aggregate, etc., the use of cement and natural aggregate is reduced, and the carbon emission of self-compacting concrete is reduced. However, as known from the above, the conventional solid waste powder is an industrial by-product, the composition of which is easy to change, which causes large differences in its performance, and the potential activity of which is mostly lower than that of cement, which easily causes performance loss. In addition, the solid waste aggregate has a high water absorption rate, and the surface layer has different slurry layers, which easily forms interface defects in the concrete, resulting in a decrease in the performance of the concrete. Therefore, the application of solid waste powder and aggregate in the preparation of self-compacting concrete will have adverse effects on the performance of the concrete, such as the performance of the mixture cannot meet the requirements of self-compacting concrete, the amount of water reducing agent to be added increases, and the mechanical properties and durability of the concrete cannot meet the requirements.

[0005] Therefore, how to prepare a solid waste self-compacting low-carbon concrete to ensure that the performance, mechanical properties and durability of the mixture meet the requirements of self-compacting concrete is a technical problem that technicians in the field are committed to solving. SUMMARY

[0006] To solve the problems of the prior art mentioned in the background, the present application provides a modified solid waste self-compacting low-carbon concrete, and the technical scheme is as follows:

[0007] The modified solid waste self-compacting low-carbon concrete provided by the application comprises the following raw material components: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and polycarboxylic acid high-performance water reducing agent; the modified solid waste slurry is obtained by sequentially subjecting solid waste mixed powder to mixing treatment with water and modification treatment with a modifier; wherein the solid waste mixed powder comprises two or more combinations of solid waste powder with an average particle size of 2 microns, solid waste powder with an average particle size of 3 microns, solid waste powder with an average particle size of 7 microns, solid waste powder with an average particle size of 10 microns, and solid waste powder with an average particle size of 20 microns; the components of the modifier include one or more combinations of graphene dispersion liquid, carbon nanotube dispersion liquid, and nano-silicon dioxide suspension; the modified solid waste aggregate is obtained by sequentially subjecting solid waste mixed aggregate to soaking treatment in a low-concentration hydrochloric acid solution, modification treatment by interface enhancer rinsing, and drying treatment; wherein the interface enhancer is one or more combinations of organic silicon, water-based resin, silicic acid-based enhancer, and acrylic acid enhancer.

[0008] In some embodiments, the solid waste mixed aggregate comprises, in parts by weight, 34-40 parts of solid waste aggregate with a particle size of 0-2.5 mm (excluding 0 mm), 4-11 parts of solid waste aggregate with a particle size of 2.5-5 mm, 11-33 parts of solid waste aggregate with a particle size of 5-10 mm, and 22-44 parts of solid waste aggregate with a particle size of 10-20 mm; and the mass concentration of the hydrochloric acid solution is 0.05%-1%.

[0009] In some embodiments, the preparation process of the modified solid waste slurry is as follows: first, solid waste powder raw materials are treated by mechanical grinding to obtain solid waste powder with different average particle size ranges, and then the solid waste powder with different average particle size ranges is mixed to obtain the solid waste mixed powder; the solid waste mixed powder is mixed with water and stirred uniformly; finally, the modifier is added and stirred uniformly to obtain the modified solid waste slurry; wherein the weight ratio of the solid waste mixed powder, the water, and the modifier is (80-100):(50-70):(3-7); and the components of the solid waste powder include two or more combinations of mineral powder, fly ash, ceramic polishing powder, glass powder, and limestone powder.

[0010] In some embodiments, the preparation process of the modified solid waste aggregate is as follows: first, building solid waste is subjected to crushing and shaping treatment to obtain solid waste aggregate with different particle size ranges, and then the solid waste aggregate with different particle size ranges is mixed to form solid waste mixed aggregate; the solid waste mixed aggregate is added into a low-concentration hydrochloric acid solution to remove part of the cement particles remaining on the surface of the aggregate; and then the initial treatment solid waste mixed aggregate is obtained by sequentially subjecting the solid waste mixed aggregate to filtration, water washing, and drying; the initial treatment solid waste mixed aggregate is then subjected to modification treatment by interface enhancer rinsing, and finally the modified solid waste aggregate is obtained by drying.

[0011] In some embodiments, the components of the solid waste powder are composed of mineral powder, fly ash, and ceramic polishing powder; the solid waste mixed powder is composed of solid waste powder with an average particle size of 2 microns, solid waste powder with an average particle size of 7 microns, and solid waste powder with an average particle size of 10 microns, mixed in a weight ratio of 4:3:3.

[0012] In some embodiments, the raw material components include, by weight: cement 220-260 parts, modified solid waste slurry 220-260 parts, silica fume 20-40 parts, modified solid waste aggregate 1700-1750 parts, water 65-80 parts, and high-performance water reducing agent 4-6 parts.

[0013] In some embodiments, the cement is one of P·O 42.5R cement, P·O 42.5 cement, and P·II 42.5 cement.

[0014] In some embodiments, the silica fume is silica powder modified by a silane coupling agent, with a silica content of 90-95%, a bulk density of 250 kg / m 3 -300 kg / m 3 , a loss on ignition of 1-4%, a 7d activity index of 105-110%, and a specific surface area of 19000 m 2 / kg-23000 m 2 / kg.

[0015] In some embodiments, the high-performance water reducing agent is compounded from polycarboxylic acid comprehensive type water reducing mother liquor, shrinkage reducing agent, retarder, slump retaining agent, cellulose, adjusting agent, air entraining agent, and water in a weight ratio of (240-280):(330-500):(10-20):(20-50):(5-10):(1-3):(0.5-1):(200-330), with a solid content of 17-22%, a water reducing rate of 28-33%, and a 28d compressive strength ratio of 143-150%.

[0016] The high-performance water reducing agent has a strong dispersing effect on cementitious materials, can significantly adjust the workability of concrete, enhance the interfacial bonding force between the concrete paste and aggregate, and improve the paste strength and reduce the shrinkage of concrete.

[0017] The application also provides a preparation method of the modified solid waste self-compacting low-carbon concrete, comprising the following preparation steps: weighing cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water and high-performance water reducing agent according to a formula; mixing and stirring the first part of water and the silica fume uniformly to obtain slurry A; mixing and stirring the modified solid waste slurry and the slurry A uniformly to obtain slurry B; mixing and stirring the cement and the slurry B uniformly to obtain slurry C; mixing and stirring the second part of water, the high-performance water reducing agent and the slurry C uniformly to obtain slurry D; pouring the modified solid waste aggregate into the slurry D and mixing and stirring uniformly to obtain a self-compacting concrete mixture; and curing and shaping the mixture to obtain the modified solid waste self-compacting low-carbon concrete.

[0018] In some embodiments, the preparation method comprises the following preparation steps: weighing cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water and high-performance water reducing agent according to a formula; pouring the first part of water and the silica fume into a stirrer, mixing and stirring uniformly for 20-40 s to obtain slurry A; mixing and stirring the modified solid waste slurry and the slurry A uniformly for 10-20 s to obtain slurry B; mixing and stirring the cement and the slurry B uniformly for 10-20 s to obtain slurry C; mixing and stirring the second part of water, the high-performance water reducing agent and the slurry C uniformly for 15-30 s to obtain slurry D; pouring the modified solid waste aggregate into the slurry D and mixing and stirring uniformly for 60-90 s to obtain a self-compacting concrete mixture; wherein the flow degree of the mixture is controlled to be 650-700 mm; the mixture is cured and shaped to obtain the modified solid waste self-compacting low-carbon concrete; wherein the total amount of water is the sum of the first part of water and the second part of water, and the weight ratio of the first part of water to the second part of water is 2:1.

[0019] Compared with the prior art, the application has the following technical effects:

[0020] The application provides a modified solid waste self-compacting low-carbon concrete, which is prepared by modifying and optimizing solid waste materials, and by optimizing the mixing proportion of the solid waste self-compacting concrete and configuring a special additive for the solid waste self-compacting low-carbon concrete, so that the modified solid waste slurry and the modified solid waste aggregate can effectively play a role in the concrete, so as to improve the mechanical properties and durability of the concrete, and ensure that the rheological properties of the concrete can meet the requirements of the self-compacting concrete. The application applies the solid waste powder and the aggregate to the self-compacting concrete, so as to achieve waste utilization and low-carbon effect. DETAILED DESCRIPTION

[0021] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0022] The present application provides a preparation method of modified solid waste self-compacting low-carbon concrete:

[0023] The preparation method comprises the following preparation steps:

[0024] The cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and high-performance water reducing agent are weighed according to the formula; the mixing water is divided into two parts in a weight ratio of 2:1, the first part of the larger amount of water and the silica fume are poured into a stirrer, and are stirred and mixed uniformly for 20 s to 40 s to obtain slurry A; the modified solid waste slurry and the slurry A are stirred and mixed uniformly for 10 s to 20 s to obtain slurry B; the cement and the slurry B are stirred and mixed uniformly for 10 s to 20 s to obtain slurry C; the second part of the remaining water and the high-performance water reducing agent are stirred and mixed uniformly with the slurry C for 15 s to 30 s to obtain slurry D; the modified solid waste aggregate is poured into the slurry D, and is stirred and mixed uniformly for 60 s to 90 s to obtain a self-compacting concrete mixture; wherein the flow degree of the mixture is controlled to be between 650 mm and 700 mm; and the mixture is solidified and formed to obtain the modified solid waste self-compacting low-carbon concrete. The formula of the concrete is as follows:

[0025] The raw material components include, by weight, 220 parts to 260 parts of cement, 220 parts to 260 parts of modified solid waste slurry, 20 parts to 40 parts of silica fume, 1700 parts to 1750 parts of modified solid waste aggregate, 65 parts to 80 parts of water, and 4 parts to 6 parts of high-performance water reducing agent.

[0026] The modified solid waste slurry is obtained by sequentially mixing and treating the solid waste mixed powder with water and modifying the modified agent, and the preparation process is as follows:

[0027] The modified solid waste slurry is obtained by sequentially mixing and treating the solid waste mixed powder with water and modifying the modified agent, and the preparation process is as follows:

[0028] (1) The solid waste powder raw material is first treated by mechanical grinding to obtain solid waste powders with different average particle size ranges, and then the solid waste powders with different average particle size ranges are mixed to obtain the solid waste mixed powder;

[0029] The components of the solid waste powder include two or more combinations of mineral powder, fly ash, ceramic polishing powder, glass powder, and limestone powder; the solid waste mixed powder includes two or more combinations of solid waste powder with an average particle size of 2 μm, solid waste powder with an average particle size of 3 μm, solid waste powder with an average particle size of 7 μm, solid waste powder with an average particle size of 10 μm, and solid waste powder with an average particle size of 20 μm. Preferably, the solid waste mixed powder is obtained by mixing solid waste powder with an average particle size of 2 μm, solid waste powder with an average particle size of 7 μm, and solid waste powder with an average particle size of 10 μm at a weight ratio of 4:3:3.

[0030] It should be noted that the solid waste powder is a mixture of recycled waste materials, which is a mixture of micro-powder materials such as mineral powder, fly ash, ceramic polishing powder, glass powder, and limestone powder, and no specific formula ratio is limited. For example, mineral powder, fly ash, and ceramic polishing powder can be selected and mixed at a weight ratio of (30-50):(20-30):(30-40).

[0031] (2) The solid waste mixed powder is mixed with water and stirred uniformly; finally, a modifier is added and stirred uniformly to obtain a modified solid waste slurry.

[0032] The components of the modifier include one or more combinations of graphene dispersion liquid, carbon nanotube dispersion liquid, and nano-silicon dioxide suspension; and the weight ratio of the solid waste mixed powder, the water, and the modifier is (80-100):(50-70):(3-7).

[0033] The modified solid waste aggregate is obtained by sequentially immersing the solid waste mixed aggregate in a low-concentration hydrochloric acid solution, rinsing and modifying the interface with an interface enhancer, and drying.

[0034] The modified solid waste aggregate is obtained by sequentially immersing the solid waste mixed aggregate in a low-concentration hydrochloric acid solution, rinsing and modifying the interface with an interface enhancer, and drying.

[0035] (1) The construction solid waste is first crushed and shaped to obtain solid waste aggregates with different particle size ranges, and the solid waste aggregates with different particle size ranges are mixed to form a solid waste mixed aggregate.

[0036] The solid waste mixed aggregate includes, by weight, 34-40 parts of solid waste aggregate with a particle size of 0 mm-2.5 mm, 4-11 parts of solid waste aggregate with a particle size of 2.5 mm-5 mm, 11-33 parts of solid waste aggregate with a particle size of 5 mm-10 mm, and 22-44 parts of solid waste aggregate with a particle size of 10 mm-20 mm.

[0037] (2) The solid waste mixed aggregate is added to a low-concentration hydrochloric acid solution to remove part of the cement particles remaining on the surface of the aggregate; and then sequentially filtered, washed with water, and dried to obtain a preliminarily treated solid waste mixed aggregate; wherein the mass concentration of the hydrochloric acid solution is 0.05%-1%.

[0038] (3) using an interface reinforcing agent to perform a wetting modification treatment on the primary treated solid waste mixed aggregate, and finally naturally drying for 7-15 days to obtain the modified solid waste aggregate; wherein the interface reinforcing agent is one or a combination of multiple of organic silicon, water-based resin, silicic acid-based reinforcing agent, and acrylic acid reinforcing agent.

[0039] It should be noted that:

[0040] The building solid waste generally refers to waste concrete test blocks obtained after house demolition, and some aggregate obtained after crushing and breaking (the aggregate surface will adhere to some concrete slurry, and therefore the key of the acid soaking step in the modification process lies in removing the adhered slurry).

[0041] During the low-concentration hydrochloric acid solution soaking treatment process, the amount of the hydrochloric acid solution can be sufficient to soak the solid waste mixed aggregate, and no excessive limitation is made.

[0042] During the interface reinforcing agent wetting modification treatment process, the amount of the interface reinforcing agent can be sufficient to contact and wet the primary treated solid waste mixed aggregate, and no excessive limitation is made.

[0043] The application also provides the formulations (unit: weight parts) of the examples and comparative examples shown in Table 1:

[0044] Table 1

[0045]

[0046] Specifically, the preparation process of the examples and comparative examples and the comparative examples provided by the application is as follows:

[0047] Example 1

[0048] In this embodiment, the compositions of the raw materials in weight parts include: cement 260 parts, modified solid waste slurry 220 parts, silica fume 20 parts, modified solid waste aggregate 1750 parts, water 80 parts, and high-performance water reducing agent 4.5 parts.

[0049] 1. The preparation method of the modified solid waste slurry, and the specific steps are as follows:

[0050] (1) A plurality of solid waste powder raw materials are first ground by a machine to form solid waste powders of different particle size ranges, and the solid waste powders of different particle size ranges are mixed to form a solid waste mixed powder;

[0051] The components of the solid waste powder include mineral powder, fly ash, and ceramic polishing powder, and the weight ratio of the three is 45:20:35. The solid waste mixed powder is formed by mixing solid waste powders with average particle sizes of 2 μm, 7 μm, and 10 μm at a weight ratio of 4:3:3.

[0052] (2) The solid waste mixed powder is mixed with water, and then uniformly stirred for 20 min.

[0053] (3) Pour in the modifier again, stir evenly, stirring time is 45 min, stand by. Among them, the modifier is carbon nanotube dispersion liquid, specifically GTCO 301. The weight ratio of solid waste mixed powder, water and modifier is 90:56:4.

[0054] 2. The preparation method of the modified solid waste aggregate, the specific steps are as follows:

[0055] (1) The building solid waste is first crushed and shaped to prepare solid waste aggregates of multiple particle sizes, and the solid waste aggregates of multiple particle sizes are mixed to form a solid waste mixed aggregate. Among them, the solid waste mixed aggregate is mixed by solid waste aggregates with particle size ranges of 0mm-2.5mm, 2.5mm-5mm, 5mm-10mm, and 10mm-20mm at a weight ratio of 40:10:19:38.

[0056] (2) Pour the solid waste mixed aggregate into a low-concentration hydrochloric acid solution to remove part of the cement particles on the surface of the aggregate, and then filter, wash with water and dry; wherein the concentration of the hydrochloric acid solution is 0.1%.

[0057] (3) Then put the aggregate into a grid barrel, rinse and modify with an interfacial reinforcing agent, and finally dry naturally for 7 days to obtain a modified solid waste aggregate. Among them, the interfacial reinforcing agent is an organic silicon reinforcing agent, specifically R06.

[0058] 3. Other raw materials

[0059] The cement is Runfeng P·O 42.5 cement, with a 28d compressive strength of 47.1MPa and a 28d flexural strength of 8.9MPa;

[0060] The silica fume is a kind of silica powder modified by silane coupling agent, with a silicon dioxide content of 94%, a bulk density of 265kg / m 3 , a loss on ignition of 1.6%, a 7d activity index of 107%, and a specific surface area of 19300m 2 / kg.

[0061] The high-performance water reducing agent is compounded by polycarboxylic acid comprehensive type water reducing mother liquor, shrinkage reducing agent, retarder, slump retaining agent, cellulose, adjusting agent, air entraining agent and water, with a weight ratio of 240:350:10:25:5:2:0.6:300. Specifically, it is Point-50SCS of Kechengjie New Material Group Co., Ltd.

[0062] It has a strong dispersing effect on cementitious materials, can significantly adjust the workability of concrete, enhance the interfacial adhesion between concrete paste and aggregate, improve the paste strength, and reduce the shrinkage of concrete. Its solid content is 19%, the water reducing rate is 28%, and the 28d compressive strength ratio is 145%.

[0063] The preparation method of the modified solid waste self-compacting low-carbon concrete comprises the following preparation steps:

[0064] 1. Weigh each raw material component: weigh the cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and high-performance water reducing agent according to a certain weight fraction;

[0065] 2. Divide the mixing water into two parts in a ratio of 2:1, pour the larger amount of water into the mixer first, then pour in the silica fume, and stir for 30 seconds to obtain slurry A;

[0066] 3. Mix the modified solid waste slurry with slurry A uniformly, stir for 20 seconds to obtain slurry B;

[0067] 4. Mix the cement and slurry B uniformly, stir for 20 seconds to obtain slurry C;

[0068] 5. Mix the remaining small amount of water and high-performance water reducing agent with slurry C uniformly, stir for 20 seconds to obtain slurry D;

[0069] 6. Pour the modified solid waste aggregate into slurry D and stir for 90 seconds to obtain a self-compacting concrete mixture, and the flow degree of the mixture is controlled between 650mm and 700mm;

[0070] 7. Use part of the obtained mixture for mixture performance testing, and use the remaining part for mechanical and durability performance testing by molding method: directly pour into a fixed mold without vibration or insertion, and the surface is scraped flat, and after standard curing for 28 days, test the various performances.

[0071] Example 2

[0072] In this example, the composition of each raw material includes: cement 240 parts, modified solid waste slurry 240 parts, silica fume 30 parts, modified solid waste aggregate 1750 parts, water 70 parts, and high-performance water reducing agent 5.4 parts.

[0073] 1. The preparation method of the modified solid waste slurry comprises the following specific steps:

[0074] (1) First, grind a plurality of solid waste powder raw materials by mechanical grinding to form solid waste powders of different particle size ranges, and mix the solid waste powders of different particle size ranges to form a solid waste mixed powder;

[0075] Among them, the components of the solid waste powder include mineral powder, fly ash, and ceramic polishing powder, and the weight ratio of the three is 50:20:30. The solid waste mixed powder is mixed by solid waste powders with average particle sizes of 2μm, 7μm, and 10μm in a weight ratio of 4:3:3.

[0076] (2) Mix the solid waste mixed powder with water, and then stir uniformly for 20 minutes;

[0077] (3) Pour in the modifier, stir evenly, stirring time is 45 min, stand by. Among them, the modifier is carbon nanotube dispersion liquid, the specific selection is consistent with example 1. The weight ratio of solid waste mixed powder, water and modifier is 90:56:4.

[0078] 2. The preparation method of the modified solid waste aggregate, the specific steps are as follows:

[0079] (1) The building solid waste is first crushed and shaped to prepare solid waste aggregates of multiple particle sizes, and the solid waste aggregates of multiple particle sizes are mixed to form a solid waste mixed aggregate. Among them, the solid waste mixed aggregate is mixed by solid waste aggregates with particle size ranges of 0mm-2.5mm, 2.5mm-5mm, 5mm-10mm, and 10mm-20mm at a weight ratio of 40:10:19:38.

[0080] (2) Pour the solid waste mixed aggregate into a low-concentration hydrochloric acid solution to remove part of the cement particles on the surface of the aggregate, and then filter, wash with water and dry; wherein the concentration of the hydrochloric acid solution is 0.1%.

[0081] (3) Then put the aggregate into a grid barrel, rinse and modify with an interfacial reinforcing agent, and finally dry naturally for 7 days to obtain a modified solid waste aggregate. Among them, the interfacial reinforcing agent is an organic silicon reinforcing agent, and the specific selection is consistent with example 1.

[0082] 3. Other raw materials

[0083] The cement is Runfeng P·O 42.5 cement, with a 28d compressive strength of 47.1MPa and a 28d flexural strength of 8.9MPa; the silica fume is a kind of silica powder modified by silane coupling agent, with a silicon dioxide content of 94%, a bulk density of 265kg / m 3 , a loss on ignition of 1.6%, a 7d activity index of 107%, and a specific surface area of 19300m 2 / kg.

[0084] The high-performance water reducing agent is compounded by polycarboxylic acid comprehensive type water reducing mother liquor, shrinkage reducing agent, retarder, slump retaining agent, cellulose, adjusting agent, air entraining agent and water, with a weight ratio of 240:350:10:25:5:2:0.6:300. The specific selection of the water reducing agent is consistent with example 1. It has a strong dispersion effect on cementitious materials, can significantly adjust the workability of concrete, enhance the interfacial bonding force of concrete paste and aggregate, improve the paste strength, and reduce the shrinkage of concrete. Its solid content is 19%, the water reducing rate is 28%, and the 28d compressive strength ratio is 145%.

[0085] The preparation method of the modified solid waste self-compacting low-carbon concrete comprises the following preparation steps:

[0086] 1. Weighing each raw material component: weighing cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and high-performance water reducing agent according to a certain weight fraction;

[0087] 2. The mixing water is divided into two parts in a ratio of 2:1. Pour the larger amount of water into the blender first, then pour in the silica fume, and stir for 30 seconds to obtain slurry A;

[0088] 3. Mix the modified solid waste slurry with slurry A evenly, stir for 20 seconds to obtain slurry B;

[0089] 4. Mix the cement and slurry B evenly, stir for 20 seconds to obtain slurry C;

[0090] 5. Mix the remaining small amount of water and high-performance water reducing agent with slurry C evenly, stir for 20 seconds to obtain slurry D;

[0091] 6. Pour the modified solid waste aggregate into slurry D and stir for 90 seconds to obtain a self-compacting concrete mixture;

[0092] 7. Part of the obtained mixture is used for mixture performance test, and the remaining part is used for mechanical and durability test after molding. The molding method is: directly pour into a fixed mold, without vibration or insertion, and the surface is scraped flat. After standard curing for 28 days, test its various properties.

[0093] Example 3

[0094] In this example, the composition of each raw material includes: cement 220 parts, modified solid waste slurry 260 parts, silica fume 40 parts, modified solid waste aggregate 1750 parts, water 65 parts, and high-performance water reducing agent 6 parts.

[0095] 1. The preparation method of the modified solid waste slurry, the specific steps are as follows:

[0096] (1) A plurality of solid waste powder raw materials are first ground by a mechanical grinder to form solid waste powders of different particle size ranges. The components of the solid waste powders include mineral powder, fly ash, and ceramic polishing powder, and the weight ratio of the three is 40:20:40. The solid waste mixed powder is formed by mixing solid waste powders with average particle sizes of 2 μm, 7 μm, and 10 μm in a weight ratio of 4:3:3.

[0097] (2) Mix the solid waste mixed powder with water, and then stir evenly for 20 minutes;

[0098] (3) Pour in the modifier and stir evenly for 45 minutes, and then stand by. The modifier is a carbon nanotube dispersion liquid, which is the same as that used in Example 1. The weight ratio of the solid waste mixed powder, water, and modifier is 90:56:4.

[0099] 2. The preparation method of the modified solid waste aggregate, the specific steps are as follows:

[0100] (1) The building solid waste is first crushed and shaped to prepare solid waste aggregates of multiple particle sizes, and the solid waste aggregates of multiple particle sizes are mixed to form a solid waste mixed aggregate. The solid waste mixed aggregate is mixed by the solid waste aggregates with particle sizes of 0 mm to 2.5 mm, 2.5 mm to 5 mm, 5 mm to 10 mm, and 10 mm to 20 mm at a weight ratio of 40:10:19:38.

[0101] (2) The solid waste mixed aggregate is poured into a low-concentration hydrochloric acid solution to remove part of the cement particles remaining on the surface of the aggregate, and then filtered, washed with water, and dried; the concentration of the hydrochloric acid solution is 0.1%.

[0102] (3) The aggregate is then placed in a grid bucket and modified by washing with an interfacial reinforcing agent, and finally naturally dried for 7 days to obtain the modified solid waste aggregate. The interfacial reinforcing agent is an organic silicon reinforcing agent, and the specific selection is consistent with example 1.

[0103] 3. Other raw materials

[0104] The cement is Runfeng P·O 42.5 cement, with a 28d compressive strength of 47.1 MPa and a 28d flexural strength of 8.9 MPa;

[0105] The silica fume is a kind of silica powder modified by silane coupling agent, with a silicon dioxide content of 94%, a bulk density of 265 kg / m 3 , a loss on ignition of 1.6%, a 7d activity index of 107%, and a specific surface area of 19300 m 2 / kg.

[0106] The high-performance water reducing agent is compounded by polycarboxylic acid comprehensive type water reducing mother liquor, shrinkage reducing agent, retarder, slump retaining agent, cellulose, adjusting agent, air entraining agent, and water, with a weight ratio of 240:350:10:25:5:2:0.6:300. The specific selection of the water reducing agent is consistent with example 1. It has a strong dispersion effect on cementitious materials, can significantly adjust the workability of concrete, enhance the interfacial bonding force of concrete paste and aggregate, improve the paste strength, and reduce the shrinkage of concrete. The solid content is 19%, the water reducing rate is 28%, and the 28d compressive strength ratio is 145%.

[0107] The preparation method of the modified solid waste self-compacting low-carbon concrete includes the following preparation steps:

[0108] 1. Weigh the raw material components: weigh the cement, modified solid waste paste, silica fume, modified solid waste aggregate, water, and high-performance water reducing agent according to the certain weight fraction;

[0109] 2. Divide the mixing water into two portions in a ratio of 2:1. Pour the larger portion of water into the mixer first, then add the silica fume and mix for 30 seconds to obtain slurry A.

[0110] 3. Mix the modified solid waste slurry with slurry A evenly for 20 seconds to obtain slurry B;

[0111] 4. Mix the cement and grout B evenly for 20 seconds to obtain grout C;

[0112] 5. Mix the remaining small amount of water and high-performance water-reducing agent with slurry C evenly for 20 seconds to obtain slurry D;

[0113] 6. Pour the modified solid waste aggregate into slurry D and stir for 90 seconds to obtain a self-compacting concrete mixture.

[0114] 7. Use the obtained mixture part for mixture performance testing, and the remaining part for molding testing of mechanical and durability properties. Molding method: pour directly into a fixed mold without vibration or tamping, and scrape the surface smooth. After standard curing for 28 days, test its various properties.

[0115] Comparative Example 1

[0116] The only difference between Comparative Example 1 and Example 3 is that in Comparative Example 1, the modified solid waste slurry in Example 3 is replaced by conventional mineral admixtures and water. The total weight of conventional mineral admixtures and water is 260 parts. Since the solid content of the modified solid waste slurry in Example 3 is 90 / 150, the weight ratio of conventional mineral admixtures and water is set to 90:60, that is, 156 parts of conventional mineral admixtures and 104 parts of water.

[0117] Among them, the conventional mineral admixture is the same powder as the solid waste slurry before grinding in Example 3, that is, the various solid waste powders before mechanical grinding in step (1) of the modified solid waste slurry preparation in Example 3 are used as the conventional mineral admixture in Comparative Example 1, and other conditions remain unchanged.

[0118] Comparative Example 2

[0119] The only difference between Comparative Example 2 and Example 3 is that Comparative Example 2 replaces the modified solid waste aggregate of Example 3 by weight with solid waste aggregate with a dual particle size range, while keeping other conditions unchanged.

[0120] Specifically, the solid waste aggregate with dual particle size range is a mixture of 0mm-5mm solid waste aggregate and 10mm-20mm solid waste aggregate at a weight ratio of 50:57. The source of the solid waste aggregate with dual particle size range is the same as that in Example 3, using the same batch of construction solid waste as in Example 3, which is crushed and shaped in step (1) to prepare solid waste aggregate with the required particle size.

[0121] Comparative Example 3

[0122] The difference between the present comparative example 3 and example 3 is that the modified solid waste aggregate in example 3 is replaced by ordinary aggregate in the present comparative example 3, and other conditions remain unchanged.

[0123] The ordinary aggregate is machine-made sand and gravel, and the weight ratio of the two is 50:57. The machine-made sand is two-zone sand with a fineness of 2.5, and the gravel is continuously graded gravel with a size of 5mm-20mm.

[0124] Comparative example 4

[0125] The difference between the present comparative example 4 and example 3 is that the modified solid waste slurry in example 3 is replaced by unmodified solid waste slurry in the present comparative example 4, i.e. the mixture of solid waste mixture and water prepared in step (2) of example 3 is replaced by the modified solid waste slurry in example 3, and other conditions remain unchanged.

[0126] Comparative example 5

[0127] The difference between the present comparative example and example 3 is that in step (1) of preparing the modified solid waste slurry, a single average particle size solid waste powder (average particle size of 10μm) is selected to replace the mixed solid waste powder with three different particle size ranges in example 3, and then the modified solid waste slurry is obtained by sequentially mixing with water and modifying with a modifier, and other steps and conditions remain unchanged.

[0128] The composition of the solid waste powder in the present comparative example is the same as that in example 3, i.e. mineral powder, fly ash and ceramic polishing powder are mixed in a specific ratio. The difference between the present comparative example and example 3 is that the solid waste powder is not a mixture of three particle size ranges in a specific ratio.

[0129] Comparative example 6

[0130] The difference between the present comparative example and example 3 is that in step (1) of preparing the modified solid waste aggregate, a solid waste mixed aggregate with a weight ratio of 50:57 of 0mm-5mm solid waste aggregate and 10mm-20mm solid waste aggregate is selected to replace the solid waste mixed aggregate with four different particle size ranges in example 3, and then the modified solid waste aggregate is obtained by sequentially soaking in a low-concentration hydrochloric acid solution, modifying with an interfacial enhancer and drying, and other steps and conditions remain unchanged.

[0131] The source of the solid waste aggregate in the present comparative example is the same as that in example 3, i.e. the construction solid waste of the same batch as in example 3 is crushed and shaped to obtain solid waste aggregate with the required particle size. The difference between the present comparative example and example 3 is that the solid waste mixed aggregate is not a mixture of four particle size ranges in a specific ratio.

[0132] It should be noted that:

[0133] In order to keep the spreadability of the concrete mixture of the comparative examples 1-6 at the same level as that of example 3 (i.e., the same initial state) for the purpose of comparing the performance of the comparative examples with the example, the amount of water reducing agent in the comparative examples 1-6 needs to be adjusted. This is to compare the performance difference between the comparative examples with the example, which takes the solid waste slurry and solid waste aggregate as variables, and not to introduce the amount of water reducing agent as a variable.

[0134] Performance test of products prepared in examples and comparative examples:

[0135] The concrete prepared in the above examples and comparative examples was tested for performance according to the standards T / CECS 203-2021 "Technical Specification for Application of Self-compacting Concrete", GB / T 50081-2019 "Standard Test Methods for Physical and Mechanical Properties of Concrete", and GB / T 50082-2009 "Standard Test Methods for Long-term Performance and Durability of Ordinary Concrete", and the results are shown in Table 2:

[0136] Table 2

[0137]

[0138] In Table 2, the slump, spread, spread time, and J-ring height difference are the performance of freshly mixed self-compacting concrete mixture; 28d represents the compressive strength and chloride ion migration coefficient of the concrete after 28 days of standard curing.

[0139] From the test results in Table 2, it can be seen that:

[0140] The test results of examples 1-3 show that as the amount of modified solid waste slurry increases and the amount of cement decreases, the amount of water reducing agent needs to be increased to meet the flowability requirements of self-compacting concrete, indicating that the modified solid waste slurry is more easily adsorbed by water than cement, resulting in a decrease in flowability. As the amount of modified solid waste slurry increases, the spread time increases and the J-ring height difference decreases, indicating that the slurry viscosity increases slightly and the gap passing property is enhanced, which is more conducive to the movement of aggregate in narrow spaces. As the amount of modified solid waste slurry increases, the mechanical properties and durability of self-compacting concrete are also enhanced, which is not only due to the effect of modified solid waste slurry, but also due to the effect of silica fume.

[0141] The modified solid waste slurry and the modified solid waste aggregate can effectively play a role in the concrete to improve the mechanical properties and durability of the concrete, and ensure that the rheological properties of the concrete can meet the requirements of self-compacting concrete.

[0142] Compared with Example 3, the high-performance water reducing agent dosage of Comparative Example 1 is reduced under the premise of keeping the spread degree about the same, but the compressive strength and durability decrease, which shows that the modified solid waste slurry of the application is more easily adsorbed by the additive and water through the refining effect of physical grinding; the solid waste powder of the application improves the cohesiveness of the concrete through physical grinding and modification, the slurry can more effectively promote the rolling of the aggregate, and has a great enhancement effect on the strength and chloride ion penetration resistance of the concrete. When the water reducing agent dosage of Comparative Example 1 is kept consistent with Example 3, the slump is 235 mm, the spread degree is 740 mm, the spread time is 2.6 s, and the J-ring height difference is 34 mm; the 28d compressive strength and the chloride ion migration coefficient are 47.6 MPa and 5.2 x 10 -12 m 2 / s, respectively, which shows that the mixture of Comparative Example 1 appears segregation under the same dosage, and cannot meet the performance requirements of self-compacting concrete, so it is necessary to reduce the dosage of high-performance water reducing agent to control the workability.

[0143] Compared with Example 3, Comparative Example 2 only uses solid waste aggregate with a double particle size range, and the waste aggregate is not modified, which has a greater influence on the fluidity of the concrete, and needs to increase the dosage of high-performance water reducing agent to improve the fluidity. The reason is that the unmodified solid waste aggregate has strong water absorption, which can adsorb part of the water for concrete, resulting in a decrease in the water amount for powder, and an increase in the viscosity of the concrete. The double particle size range of the solid waste aggregate has a large stacking void ratio, and the gap passability is poor. The application can effectively improve the gap passability and enhance the rheological properties of self-compacting concrete by combining multiple particle sizes of aggregate. The modified solid waste aggregate of the application can significantly improve the strength and durability of the concrete, and the reason is that the acid washing removes the weak cement layer on the surface of the aggregate, reduces the transition zone of new and old mortar, reduces the internal cracks, and the organic silicon reinforcing agent can penetrate into the interior of the solid waste aggregate, enhance the strength of the aggregate, and form an external film to reduce the water absorption of the solid waste aggregate and ensure the stability of the water amount.

[0144] Compared with Example 3, the waste material is not used in Comparative Example 3, but 5mm-20mm continuous gradation ordinary aggregate, the performance measured by the waste utilization scheme (especially Example 3) of the present application is close to that of the modified solid waste aggregate, which shows that the modification effect of the scheme of the present application is good, which can reduce the water absorption of the solid waste aggregate and improve the strength of the aggregate, so that the performance is close to that of the ordinary aggregate. Although the traditional scheme using ordinary aggregate has good comprehensive performance, but it uses ordinary aggregate, which cannot utilize waste to reduce carbon emissions compared with the present application, and the raw material cost is higher.

[0145] Compared with Example 3, Comparative Example 4 uses unmodified solid waste slurry, and the main difference in performance is that the compressive strength and chloride ion migration coefficient of Comparative Example 4 are poor, which shows that the modifier used in the present application can optimize the internal slurry pore structure, block the chloride ion transmission channel, and improve the strength and durability of the self-compacting concrete.

[0146] Compared with Example 3, Comparative Example 5 uses a single particle size of solid waste powder to prepare a modified solid waste slurry, and the main difference in performance is that the J-ring height difference is large, the compressive strength is reduced, and the chloride ion penetration resistance is poor. Single particle size powder cannot be effectively combined with cement, and the formed cementitious material gradation curve appears single-peak convex, which affects the overall performance of the concrete.

[0147] Compared with Example 3, Comparative Example 6 uses a double-particle-size modified solid waste aggregate, and the main difference in performance is the J-ring height difference and the compressive strength. The mixture of double-particle-size aggregate is prone to aggregate accumulation, and the slurry cannot effectively promote the dispersion and forward movement of the aggregate, resulting in a decrease in the performance of the self-compacting concrete. Specifically, the J-ring height difference exceeds the limited range, and the compressive strength and durability of the concrete are poor.

[0148] Compared with Comparative Example 2, the water absorption of the modified aggregate is significantly reduced, and the performance is optimized, which shows that it has an improvement effect on the self-compacting concrete.

[0149] In summary, compared with the prior art, the preparation method of the coating for titanium alloy substrate high-bonding force antifouling and drag reduction provided by the present application has the following design concepts and beneficial effects:

[0150] Design concept:

[0151] The present application scheme takes the double modification of solid waste powder and aggregate as the core, combines and matches a plurality of particle size ranges of micro-powder prepared by physical grinding of a plurality of different solid waste powders to achieve the best packing effect, uses water as a medium to make it into a slurry state, reduces the aggregation caused by too fine particles, and further improves its uniformity. Finally, the modifier is matched to optimize the pore structure, reduce the generation of large pores and connected pores, and improve the mechanical properties and durability of the concrete.

[0152] The application scheme further modifies the building solid waste to obtain modified solid waste aggregate. The aggregate roundness of the solid waste aggregate can be reinforced, the interface between the aggregate and the slurry can be improved, the aggregate and the slurry can be moved cooperatively, the fluidity and the gap passing rate can be increased, and the optimal 5 mm-20 mm continuous gradation can be formed in a variety of single particle level combination modes to reduce the aggregate void ratio and increase the density. During the crushing process of the building solid waste, part of the cement slurry adheres to the surface of the aggregate to become a weak layer, which reduces the performance of the concrete. Through the acid pickling mode, the amount of cement on the surface of the aggregate is reduced, and through the interface reinforcement mode, the surface of the aggregate is hardened and penetrates into the interior of the aggregate to reduce the water absorption rate of the aggregate and enhance the stability and performance of the aggregate. The application applies the solid waste powder and the aggregate to the self-compacting concrete to make waste useful and achieve the effect of low carbonization.

[0153] Beneficial effects:

[0154] The application provides a modified solid waste self-compacting low-carbon concrete. The modified solid waste powder and the modified solid waste aggregate are mixed to effectively solve the problem of large carbon emission of the concrete. More significantly, the modified solid waste can effectively play a stable role in the concrete to effectively improve the mechanical properties and durability of the concrete. Finally, by optimizing the mixing proportion of the solid waste self-compacting concrete and configuring the special additive for the solid waste self-compacting low-carbon concrete, the rheological properties of the concrete can meet the requirements of the self-compacting concrete.

[0155] It should be noted that:

[0156] Unless otherwise specified, the "~" in the present application represents a numerical range, and the range represented by the expression includes both end point values.

[0157] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments under the concept of the application, but are not limited thereto; those skilled in the art can make adaptive adjustments within the concept and protection scope of the application.

[0158] In addition, unless otherwise specified, the raw materials used can be conventional commercially available products in the art or prepared by conventional methods in the art; that is, the reagents and instruments used in the present embodiments are not marked with the manufacturer and the like, and are conventional products that can be purchased in the market.

[0159] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A self-compacting low-carbon concrete incorporating modified solid waste, characterized in that, It includes the following raw material components: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and polycarboxylate superplasticizer; The modified solid waste slurry is obtained by sequentially mixing solid waste powder with water and then modifying it with a modifier. The solid waste powder comprises two or more of the following: solid waste powder with an average particle size of 2 μm, solid waste powder with an average particle size of 3 μm, solid waste powder with an average particle size of 7 μm, solid waste powder with an average particle size of 10 μm, and solid waste powder with an average particle size of 20 μm; the modifier comprises one or more of the following: graphene dispersion, carbon nanotube dispersion, and nano-silica suspension. The modified solid waste aggregate is obtained by sequentially treating the mixed solid waste aggregate with a low-concentration hydrochloric acid solution, washing and modifying it with an interface reinforcing agent, and drying it; wherein the interface reinforcing agent is one or more of organosilicon, water-based resin, silicate reinforcing agent, and acrylic reinforcing agent.

2. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that: By weight, the solid waste mixed aggregate comprises 34-40 parts of solid waste aggregate with a particle size of 0mm-2.5mm, 4-11 parts of solid waste aggregate with a particle size of 2.5mm-5mm, 11-33 parts of solid waste aggregate with a particle size of 5mm-10mm, and 22-44 parts of solid waste aggregate with a particle size of 10mm-20mm; wherein, the solid waste aggregate with a particle size of 0mm-2.5mm does not include solid waste aggregate with a particle size of 0mm. The hydrochloric acid solution has a mass concentration of 0.05% to 1%.

3. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that, The preparation process of the modified solid waste slurry is as follows: First, the solid waste powder raw material is mechanically ground to obtain solid waste powder with different average particle size ranges. Then, the solid waste powder with different average particle size ranges is mixed to obtain the solid waste mixed powder. The solid waste powder is mixed with water and stirred evenly; finally, a modifier is added and stirred evenly to obtain a modified solid waste slurry. The weight ratio of the solid waste powder, water, and modifier is (80-100):(50-70):(3-7); the solid waste powder comprises two or more of the following: mineral powder, fly ash, ceramic polishing powder, glass powder, and limestone powder.

4. The self-compacting low-carbon concrete with modified solid waste as described in claim 1, characterized in that, The preparation process of the modified solid waste aggregate is as follows: Construction solid waste is first crushed and shaped to obtain solid waste aggregates with different particle size ranges. The solid waste aggregates with different particle size ranges are then mixed to form solid waste mixed aggregates. The solid waste mixed aggregate is added to a low-concentration hydrochloric acid solution to remove some of the cement particles remaining on the surface of the aggregate; then it is filtered, washed with water and dried in sequence to obtain the pre-treated solid waste mixed aggregate. The pre-treated solid waste aggregate is wetted and modified by an interface enhancer, and then dried to obtain the modified solid waste aggregate.

5. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that: The solid waste powder is composed of mineral powder, fly ash, and ceramic polishing powder. The solid waste powder mixture is composed of solid waste powder with an average particle size of 2 μm, solid waste powder with an average particle size of 7 μm, and solid waste powder with an average particle size of 10 μm, mixed in a weight ratio of 4:3:

3.

6. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that: By weight, its raw material components include: 220-260 parts cement, 220-260 parts modified solid waste slurry, 20-40 parts silica fume, 1700-1750 parts modified solid waste aggregate, 65-80 parts water, and 4-6 parts high-performance water-reducing agent.

7. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that: The cement is one of P·O 42.5R cement, P·O 42.5 cement, and P·II 42.5 cement; The silica fume is silica powder modified with a silane coupling agent, with a silica content of 90%–95% and a bulk density of 250 kg / m³. 3 ~300kg / m 3 Loss on ignition is 1%–4%, 7-day activity index is 105%–110%, and specific surface area is 19000 m². 2 / kg~23000 m 2 / kg.

8. The self-compacting low-carbon concrete with added modified solid waste according to claim 1, characterized in that: The high-performance water-reducing agent is composed of polycarboxylate composite water-reducing mother liquor, shrinkage reducer, retarder, slump retainer, cellulose, regulator, air-entraining agent and water in a weight ratio of (240-280):(330-500):(10-20):(20-50):(5-10):(1-3):(0.5-1):(200-330). It has a solid content of 17%-22%, a water reduction rate of 28%-33%, and a 28-day compressive strength ratio of 143%-150%.

9. A method for preparing self-compacting low-carbon concrete with added modified solid waste as described in any one of claims 1-8, characterized in that, The preparation steps include the following: Weigh out the following ingredients according to the formula: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and high-performance water-reducing agent. The first part of water and silica fume were stirred and mixed evenly to obtain slurry A; The modified solid waste slurry is mixed evenly with slurry A to obtain slurry B; Cement and grout B are mixed evenly to obtain grout C; The second part of water, high-performance water-reducing agent and slurry C are stirred and mixed evenly to obtain slurry D; The modified solid waste aggregate is poured into slurry D and stirred until it is evenly mixed to obtain a self-compacting concrete mixture. The mixture is solidified and molded to obtain self-compacting low-carbon concrete with modified solid waste.

10. The method for preparing self-compacting low-carbon concrete with added modified solid waste according to claim 9, characterized in that: The preparation steps include the following: Weigh out the following ingredients according to the formula: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water, and high-performance water-reducing agent. Pour the first portion of water and silica fume into a mixer and mix them evenly for 20 to 40 seconds to obtain slurry A. The modified solid waste slurry is mixed evenly with slurry A for 10 to 20 seconds to obtain slurry B. Mix cement and grout B evenly for 10-20 seconds to obtain grout C. The second part of water, high-performance water-reducing agent and slurry C are stirred and mixed evenly for 15s to 30s to obtain slurry D; Modified solid waste aggregate is poured into slurry D and stirred until uniform. The stirring time is 60s to 90s to obtain a self-compacting concrete mixture. The fluidity of the mixture is controlled between 650mm and 700mm. The mixture is solidified and molded to obtain self-compacting low-carbon concrete with modified solid waste. Wherein, the sum of the first part of water and the second part of water is the total amount of water, and the weight ratio of the first part of water to the second part of water is 2:1.

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