High-performance concrete produced by utilizing waste slurry of mixing plant and preparation method of high-performance concrete

Abstract

The invention relates to the field of building materials, in particular to high-performance concrete produced from mixing plant waste slurry and a preparation method of the high-performance concrete. Main raw materials for producing the high-performance concrete by using the mixing plant waste slurry comprise the pre-treated mixing plant waste slurry, a cement material, a binding material, fly ash, slag powder, fine aggregate, coarse aggregate, a water reducing agent, a filling agent and the like. The finally prepared concrete material not only has excellent compressive mechanical strength, but also keeps excellent water resistance, decomposition resistance and the like, so that the concrete material can be used in water-based environments such as bridge engineering and water conservancy projects, and the concrete material can be used in water-based environments such as bridge engineering and water conservancy projects while the use amount of the water reducing agent is reduced. The phenomena of poor flowability, bleeding, material layering and the like caused by the addition of the waste slurry in the mixing plant are avoided, and the method has a very excellent application prospect.

Description

Technical Field

[0001] The present application relates to the field of building materials, and more specifically to a method for producing high-performance concrete using waste slurry from a mixing station and a preparation method thereof. Background Art

[0002] With the improvement of global awareness of environmental protection and the popularization of the concept of sustainable development, the construction industry is gradually shifting towards green construction. As an indispensable part of modern construction projects, ready-mixed concrete will produce a certain amount of waste slurry during its production process. These waste slurries mainly include unsolidified cement slurry, sand and gravel mixtures, and trace chemical additives. The traditional treatment method is usually to directly discharge or landfill these waste slurries, which not only wastes precious resources, but also may pollute the environment.

[0003] In recent years, researchers have begun to explore ways to recycle and reuse waste slurry from mixing stations in order to maximize resource utilization and reduce environmental pollution. Through reasonable processes and technical means, waste slurry can be converted into valuable building materials, such as for the production of high-performance concrete. However, even if the waste slurry from mixing stations can be effectively utilized, there are still some challenges in the current technology of using waste slurry from mixing stations to produce high-performance concrete. For example: First, the composition of the waste slurry is complex and changeable, resulting in unstable composition of the waste slurry, increasing the difficulty of waste slurry treatment and reuse, and the uneven performance of the final concrete; secondly, the various chemical substances contained in the waste slurry may cause various performance problems, such as waterproofness, chemical resistance and other properties, thereby reducing the quality of concrete and limiting its application environment; finally, the solid particles in the waste slurry are difficult to form a good match with cement particles, etc., thus affecting the overall stability of the final concrete material. Summary of the invention

[0004] Therefore, in order to effectively solve the above-mentioned existing problems, the present application provides a method for producing high-performance concrete using waste slurry from a mixing station and a preparation method thereof. The final concrete material not only has excellent compressive mechanical strength, but also maintains excellent water resistance, anti-decomposition and other properties, and can be used in aqueous environments such as bridge projects and water conservancy projects. It can also reduce the amount of water reducer used while avoiding poor fluidity, water seepage, and material stratification caused by the addition of waste slurry from a mixing station, and has very excellent application prospects.

[0005] As a preferred embodiment, the high-performance concrete is produced by utilizing the waste slurry from a mixing station. The raw materials, measured by mass, are: 20 to 35 parts of pre-treated waste slurry from a mixing station, 25 to 40 parts of cement, 10 to 20 parts of a binder, 8 to 15 parts of fly ash, 7 to 12 parts of slag powder, 50 to 60 parts of fine aggregate, 60 to 80 parts of coarse aggregate, 0.15 to 0.85 parts of a water reducer, 6 to 8 parts of a filler, 3 to 5.5 parts of an expansion agent, 1.5 to 2.5 parts of an antifreeze agent, and 5 to 14 parts of water.

[0006] As a preferred embodiment, the preparation method of the pre-treated mixing station waste slurry specifically includes the following steps: S1: collecting the mixing station waste slurry into a large storage tank, slowly stirring to maintain uniformity and prevent precipitation, and then preliminarily concentrating the mixing station waste slurry through gravity sedimentation to remove excess water and increase the solid content to 15-20%; S2: after the preliminary concentration, sending it to a plate and frame filter press or a belt filter press for further dehydration, squeezing out the water and retaining the solid particles to form a dense mud cake-like substance; S3: then performing two vibration screenings, the first screening using a 5-8 mm sieve to remove large-sized impurities, and the second screening using 3.5-4 mm, 2-2.5 mm and 1.2-1.8 mm sieves for multi-layer graded screening, after the screening is completed, the mixing station waste slurry is stored in a special container, and stirred regularly to maintain uniformity.

[0007] As a preferred embodiment, the solid content of the waste slurry from the pre-treatment mixing station is 30-45%.

[0008] As a preferred embodiment, the solid content of the waste slurry from the pre-treatment mixing station is 35-40%.

[0009] As a preferred embodiment, the average particle size of the solid particles in the waste slurry of the pretreatment mixing station is ≤2 mm and ≥0.5 mm.

[0010] As a preferred embodiment, the average particle size of the solid particles in the waste slurry from the pretreatment mixing station is ≤1.6mm and ≥0.8mm.

[0011] As a preferred embodiment, the cement material is ordinary Portland cement or pozzolanic Portland cement.

[0012] As a preferred embodiment, the strength grade of the cement material is 32.5 or 42.5.

[0013] As a preferred embodiment, the adhesive is a composition of a modified resin and a bisphenol A epoxy resin.

[0014] As a preferred embodiment, the mass ratio of the modified resin to the bisphenol A epoxy resin is (4-5): (1.2-1.5).

[0015] As a preferred embodiment, the epoxy equivalent of the bisphenol A epoxy resin is 170 to 185 g / eq.

[0016] As a preferred embodiment, the viscosity of the bisphenol A epoxy resin is 10000-15000 Da, and the test temperature is 25°C.

[0017] As a preferred embodiment, the preparation method of the modified resin specifically includes the following steps: S1: adding vinyl-terminated polydimethylsiloxane to an organic-inorganic mixed solvent, and adding γ-glycidyloxypropyltrimethoxysilane, heating to 70-80°C and keeping the temperature for reaction for 2-3 hours, filtering out, washing and drying to obtain pretreated siloxane; S2: adding pretreated siloxane, diethyl maleate, perfluoromethyl vinyl ether and N,N-dimethylacrylamide to toluene solvent and mixing and stirring evenly, then adding azobisisobutyronitrile and starting vacuum degassing treatment; S3: after the vacuum degassing treatment is completed, heating to 85-95°C, keeping the temperature and stirring for reaction for 4-7 hours, after the reaction is completed, adding hexahydroxymethylmelamine and cooling to 60-70°C, continuing to stir and keep the temperature for reaction for 2-3 hours, and naturally cooling to room temperature after completion, filtering out the product and washing it 3-4 times with water and methanol, and then vacuum drying at 70-80°C overnight to obtain.

[0018] As a preferred embodiment, the organic-inorganic mixed solvent is a mixed solvent of toluene and deionized water, and the mass ratio of toluene to deionized water is (2-3): (1-1.2).

[0019] As a preferred embodiment, the mass ratio of the vinyl-terminated polydimethylsiloxane to γ-glycidyloxypropyltrimethoxysilane is (5-6): (0.3-0.4).

[0020] As a preferred embodiment, the mass ratio of the pretreated siloxane, diethyl maleate, perfluoromethyl vinyl ether, N,N-dimethylacrylamide and hexahydroxymethylmelamine is (15-20): (1.5-2): (2-3): (6-8): (0.4-0.5).

[0021] By adding modified resin and bisphenol A epoxy resin as a binder for concrete, its mechanical, water resistance and anti-dispersion properties can be greatly improved. The added modified resin and bisphenol A epoxy resin can not only form a good mixed connection system in the system under a specific mixing ratio, but also its longer main chain and multiple branches can guide the particles in the waste slurry to quickly spread and spread in the cement material in the concrete, thereby avoiding the aggregation of too fine particles and affecting the overall performance of the concrete; on the other hand, the added composite resin composition can be used as a connecting medium in the concrete system, and then when external forces act, it can reduce the slip phenomenon between molecular chains or different phase systems through the bonding effect of multiple branches on the particle solids, thereby avoiding the slip cracking phenomenon under the action of external forces, and keeping the system in a silver streak state as much as possible, so as to obtain more excellent mechanical resistance; finally, the formed resin system phase can form an isolation film layer in the concrete system to block water penetration and water release through the addition of hydrophobic monomers and groups. The existence of this film layer greatly limits the degree of water intrusion into the concrete system and the efficiency of water movement in the system, thereby avoiding the rapid decomposition and collapse caused by water dissolution and intrusion, and improving water resistance and anti-dispersion performance.

[0022] As a preferred embodiment, the fly ash is at least one of Class F fly ash, Class C fly ash, activated fly ash or ultrafine fly ash.

[0023] As a preferred implementation, the fly ash is Class F fly ash or ultrafine fly ash.

[0024] As a preferred implementation, the fly ash is Class F fly ash.

[0025] As a preferred embodiment, the slag powder is at least one of S75 grade slag powder, S95 grade slag powder, S105 grade slag powder and activated slag powder.

[0026] As a preferred embodiment, the slag powder is S105 grade slag powder.

[0027] As a preferred embodiment, the fine aggregate is at least one of river sand, machine-made sand, sea sand and recycled sand.

[0028] As a preferred embodiment, the fine aggregate is river sand.

[0029] As a preferred embodiment, the average particle size of the fine aggregate is 0.5 to 3.5 mm.

[0030] As a preferred embodiment, the average particle size of the fine aggregate is 1.25 to 2.75 mm.

[0031] As a preferred embodiment, the coarse aggregate is at least one of crushed stone, gravel, recycled crushed stone and expanded perlite.

[0032] As a preferred embodiment, the coarse aggregate is crushed stone.

[0033] As a preferred embodiment, the average particle size of the coarse aggregate is 5 to 25 mm.

[0034] As a preferred embodiment, the average particle size of the coarse aggregate is 10.5-15.5 mm.

[0035] As a preferred embodiment, the water reducer is a polycarboxylate water reducer.

[0036] As a preferred embodiment, the mass ratio of the pre-treated mixing station waste slurry, cement material and water reducing agent is (25-30): (30-38): (0.15-0.45).

[0037] As a preferred embodiment, the mass ratio of the pre-treated mixing station waste slurry, cement material and water reducing agent is (26-28): (32-35): (0.2-0.3).

[0038] As a preferred embodiment, the mass ratio of the pre-treated mixing station waste slurry, the binder and the filler is (25-30): (12-18): (7-8).

[0039] As a preferred embodiment, the mass ratio of the pre-treated mixing station waste slurry, the binder and the filler is (26-28): (14-16): (7-7.6).

[0040] As a preferred embodiment, the filler is a composition of polypropylene fiber and pullulan.

[0041] As a preferred embodiment, the mass ratio of the polypropylene fiber to the amylopectin is (3-3.5): (0.6-0.8).

[0042] As a preferred embodiment, the average diameter of the polypropylene fibers is 15 to 25 μm; the average length of the polypropylene fibers is 10 to 14 mm.

[0043] As a preferred embodiment, the branch chain content of the amylopectin is 60-70%.

[0044] As a preferred embodiment, the expansion agent is a composition of calcium oxide and calcium sulphoaluminate.

[0045] As a preferred embodiment, the mass ratio of calcium oxide to calcium sulfoaluminate is (2.5-3.5):(1.5-2).

[0046] As a preferred embodiment, the antifreeze agent is at least one of calcium nitrate, urea, ethylene glycol, propylene glycol or sorbitol.

[0047] As a preferred embodiment, the antifreeze agent is sorbitol.

[0048] The second aspect of the present application provides a preparation method for producing high-performance concrete using waste slurry from a mixing station, which specifically includes the following steps: S1: adding the waste slurry from the mixing station to a mixing mixer and stirring evenly for use, then adding cement, adhesive, fly ash and slag powder in another container and stirring and mixing, slowly adding the waste slurry from the mixing station and wet mixing at a speed of 30 to 40 rpm; S2: adding the remaining raw materials after wet mixing for 15 to 20 minutes, wherein the filler is added after heating at 50 to 60° C. for 20 to 30 minutes after the remaining raw materials are added, and ensuring that all the raw materials are added and mixed at a speed of 100 to 120 rpm for 5 to 10 minutes; S3: pouring at the construction site after stirring is completed, controlling the slump to 160 to 200 mm, and immediately curing under standard curing conditions after pouring is completed, maintaining appropriate temperature and humidity, and the concrete is obtained after completion.

[0049] The beneficial effects of this application are:

[0050] 1. The present application provides a method for producing high-performance concrete using waste slurry from a mixing station. The method can maintain excellent compressive strength while maintaining excellent water resistance and waterproof penetration properties, and can effectively resist the decomposition pressure brought by an aqueous environment, thereby effectively meeting the performance requirements for concrete materials in aqueous environments such as bridge projects and water conservancy projects, and effectively reducing the amount of water reducer used, thereby achieving efficient utilization of waste slurry from a mixing station, meeting today's environmentally friendly production concept of waste utilization, and having excellent application prospects.

[0051] 2. The present application provides a method for producing high-performance concrete using waste slurry from a mixing station. By adding modified resin and bisphenol A epoxy resin as binders for concrete, a good mixed connection system can be formed in the system. Its longer main chain and multiple branches can guide the particles in the waste slurry to quickly spread and spread in the cement material in the concrete, thereby avoiding the aggregation of too fine particles and affecting the overall performance of the concrete.

[0052] 3. The present application provides a method for producing high-performance concrete using waste slurry from a mixing station. The added binder can also work together with the added filler composition to form a more stable gel interface in the concrete system. The existence of this interface not only greatly enhances its internal connection performance, improves the density of concrete, and reduces the pore size of micropores, but also maintains a suitable internal moisture content in the early stage of curing, prevents the formation of early drying shrinkage cracks, and reduces the probability of surface defects. After the curing is completed, a barrier interface can be formed to prevent the intrusion of external moisture, while avoiding the bleeding of the concrete itself, and avoiding construction stratification caused by excessive flow of moisture. DETAILED DESCRIPTION

[0053] The specific implementation examples will be used to more intuitively demonstrate and illustrate the contents of the invention content of this application. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification and should not limit the scope of the claims to be protected by this application.

[0054] Example 1

[0055] High-performance concrete is produced using waste slurry from mixing stations. The raw materials, by mass, are: 27.2 parts of pre-treated waste slurry from mixing stations, 33.1 parts of cement, 15.6 parts of binder, 10.5 parts of fly ash, 8.8 parts of slag powder, 52 parts of fine aggregate, 68.8 parts of coarse aggregate, 0.25 parts of water reducer, 7.2 parts of filler, 3.6 parts of expansion agent, 1.8 parts of antifreeze agent, and 8.5 parts of water.

[0056] The preparation method of pre-treatment of mixing station waste slurry specifically includes the following steps: S1: collecting the mixing station waste slurry into a large storage tank, slowly stirring to maintain uniformity and prevent precipitation, and then preliminarily concentrating the mixing station waste slurry through gravity sedimentation to remove excess water and increase the solid content to 18.8%; S2: after the initial concentration, sending it to a plate and frame filter press for further dehydration, squeezing out the water and retaining the solid particles to form a dense mud cake-like substance; S3: then performing two vibration screenings, the first screening using a 6.8mm sieve to remove large-sized impurities, the second screening using 3.6mm, 2.2mm and 1.6mm sieves for multi-layer graded screening, and after the screening is completed, the mixing station waste slurry is stored in a special container and stirred regularly to maintain uniformity.

[0057] The solid content of the waste slurry from the pretreatment mixing station is 38.5%.

[0058] The average particle size of solid particles in the waste slurry from the pretreatment mixing station is 1.5 mm.

[0059] The cement material is ordinary Portland cement with a strength grade of 42.5.

[0060] The adhesive is a composite of modified resin and bisphenol A epoxy resin, and the mass ratio of the two is 4.5:1.3.

[0061] The epoxy equivalent of bisphenol A epoxy resin is 182 g / eq, the viscosity is 13000 Da, the test temperature is 25° C., and the EPON 828 model product is purchased from Hanson Corporation of the United States.

[0062] The preparation method of the modified resin specifically includes the following steps, calculated by mass: S1: adding 5.4 parts of vinyl-terminated polydimethylsiloxane to 80 parts of an organic-inorganic mixed solvent (a mixed solvent of toluene and deionized water, with a mass ratio of 3:1), and adding 1.1 parts of γ-glycidyloxypropyltrimethoxysilane, heating to 75°C and keeping the temperature for reaction for 2.5 hours, filtering out, washing and drying to obtain pretreated siloxane; S2: mixing 18.8 parts of pretreated siloxane, 1.8 parts of diethyl maleate, and 2.6 parts of perfluoromethyl Vinyl ether and 7 parts of N,N-dimethylacrylamide are added to 180 parts of toluene solvent and mixed and stirred evenly, then 0.22 parts of azobisisobutyronitrile are added and vacuum degassing treatment is started; S3: After the vacuum degassing treatment is completed, the temperature is raised to 90°C, and the reaction is stirred and kept warm for 6 hours. After the reaction is completed, 0.42 parts of hexahydroxymethylmelamine are added and the temperature is lowered to 65°C, and the stirring and keeping warm reaction is continued for 2.5 hours. After completion, it is naturally cooled to room temperature, the product is filtered out and washed with water and methanol for 3 times, and then vacuum dried at 75°C overnight.

[0063] The fly ash is Class F fly ash; the slag powder is Grade S105 slag powder.

[0064] The fine aggregate is river sand with an average particle size of 2.25 mm; the coarse aggregate is crushed stone with an average particle size of 12.5 mm.

[0065] The water reducer is a polycarboxylate water reducer, which is a Melflux2651F product purchased from BASF of Germany.

[0066] The filler is a composition of polypropylene fiber and amylopectin, and the mass ratio of the two is 3.2:0.8.

[0067] The polypropylene fibers had an average diameter of 18.5 μm and an average length of 12 mm, and were purchased from Shandong Jinhongyao Engineering Materials Co., Ltd., China.

[0068] The branched chain content of amylopectin was 68%, and it was purchased from the corresponding product sold by Wuhan Chengtian Fine Chemical Co., Ltd., China.

[0069] The expansion agent is a composition of calcium oxide and calcium sulphoaluminate, and the mass ratio of the two is 3:1.8.

[0070] The antifreeze is sorbitol.

[0071] The method for preparing high-performance concrete by using waste slurry from a mixing station specifically comprises the following steps: S1: adding the waste slurry from the mixing station into a mixing mixer and stirring evenly for use, then adding cement, adhesive, fly ash and slag powder into another container and stirring and mixing, slowly adding the waste slurry from the mixing station and wet mixing at a speed of 40 rpm; S2: adding the remaining raw materials after wet mixing for 18 minutes, wherein the filler is added after heating at 55°C for 22 minutes after the remaining raw materials are added, and mixing and stirring at a speed of 120 rpm for 8 minutes after ensuring that all the raw materials are added; S3: pouring at the construction site after the stirring is completed, controlling the slump at 180 mm, and immediately curing under standard curing conditions after the pouring is completed, maintaining suitable temperature and humidity, and obtaining the concrete after completion.

[0072] Example 2

[0073] The only difference between this embodiment and Embodiment 1 is that high-performance concrete is produced by utilizing waste slurry from a mixing station. The raw materials, measured by mass, are: 30 parts of waste slurry from a pre-treated mixing station, 38 parts of cement, 18 parts of a binder, 10.5 parts of fly ash, 8.8 parts of slag powder, 52 parts of fine aggregate, 68.8 parts of coarse aggregate, 0.15 parts of a water reducer, 7 parts of a filler, 3.6 parts of an expansion agent, 1.8 parts of an antifreeze agent, and 8.5 parts of water.

[0074] The adhesive is a composite of modified resin and bisphenol A epoxy resin, and the mass ratio of the two is 5:1.2.

[0075] The filler is a composite of polypropylene fiber and amylopectin, and the mass ratio of the two is 3.5:0.6.

[0076] Example 3

[0077] The only difference between this embodiment and Embodiment 1 is that high-performance concrete is produced by utilizing waste slurry from a mixing station. The raw materials, measured by mass, are: 25 parts of waste slurry from a pre-treated mixing station, 30 parts of cement, 12 parts of a binder, 10.5 parts of fly ash, 8.8 parts of slag powder, 52 parts of fine aggregate, 68.8 parts of coarse aggregate, 0.2 parts of a water reducer, 8 parts of a filler, 3.6 parts of an expansion agent, 1.8 parts of an antifreeze agent, and 8.5 parts of water.

[0078] The adhesive is a composite of modified resin and bisphenol A epoxy resin, and the mass ratio of the two is 4:1.5.

[0079] The filler is a composite of polypropylene fiber and amylopectin, and the mass ratio of the two is 3:0.8.

[0080] Example 4

[0081] The present embodiment differs from the embodiment 1 only in the following: the preparation method of pre-treatment of mixing station waste slurry specifically comprises the following steps: S1: collecting the mixing station waste slurry into a large storage tank, slowly stirring to maintain uniformity and prevent precipitation, and then preliminarily concentrating the mixing station waste slurry by gravity sedimentation to remove excess water and increase the solid content to 16.2%; S2: after the preliminary concentration, sending it to a plate and frame filter press for further dehydration, squeezing out the water and retaining the solid particles to form a dense mud cake-like substance; S3: then performing two vibration screenings, the first screening using a 5.5 mm sieve to remove large-sized impurities, the second screening using 3.5 mm, 2 mm and 1.4 mm sieves for multi-layer graded screening, after the screening is completed, the mixing station waste slurry is stored in a special container, and stirred regularly to maintain uniformity.

[0082] The solid content of the waste slurry from the pretreatment mixing station is 35.6%.

[0083] The average particle size of solid particles in the waste slurry from the pretreatment mixing station is 1.1 mm.

[0084] Comparative Example 1

[0085] The only difference between this comparative example and Example 1 is as follows: the preparation method of pre-treatment of mixing station waste slurry specifically comprises the following steps: S1: collecting the mixing station waste slurry into a large storage tank, slowly stirring to maintain uniformity and prevent precipitation, and then preliminarily concentrating the mixing station waste slurry by gravity sedimentation to remove excess water and increase the solid content to 10.2%; S2: after the preliminary concentration, sending it to a plate and frame filter press for further dehydration, squeezing out the water and retaining the solid particles to form a dense mud cake-like substance; S3: then performing two vibration screenings, the first screening using an 8.5mm sieve to remove large-sized impurities, the second screening using 5.5mm, 3.2mm and 2.4mm sieves for multi-layer graded screening, after the screening is completed, the mixing station waste slurry is stored in a special container, and stirred regularly to maintain uniformity.

[0086] The solid content of the waste slurry from the pretreatment mixing station is 22.8%.

[0087] The average particle size of solid particles in the waste slurry from the pretreatment mixing station is 2.2 mm.

[0088] Comparative Example 2

[0089] The only difference between this comparative example and Example 1 is that the adhesive is a composition of a modified resin and a bisphenol A epoxy resin, and the mass ratio of the two is 2:3.

[0090] Comparative Example 3

[0091] The only difference between this comparative example and Example 1 is that the adhesive is a composition of a modified resin and a bisphenol A epoxy resin, and the mass ratio of the two is 8:1.

[0092] Comparative Example 4

[0093] The only difference between this comparative example and Example 1 is as follows: The preparation method of the modified resin specifically comprises the following steps, calculated in parts by mass: S1: adding 5.4 parts of vinyl-terminated polydimethylsiloxane to 80 parts of an organic-inorganic mixed solvent (a mixed solvent of toluene and deionized water, with a mass ratio of 3:1), and adding 1.1 parts of γ-glycidyloxypropyltrimethoxysilane, heating to 75°C and keeping the temperature for reaction for 2.5 hours, filtering, washing and drying to obtain pretreated siloxane;

[0094] S2: Add 30.5 parts of pretreated siloxane, 0.5 parts of diethyl maleate, 1.1 parts of perfluoromethyl vinyl ether and 5 parts of N,N-dimethylacrylamide to 220 parts of toluene solvent and mix well, then add 0.18 parts of azobisisobutyronitrile and start vacuum degassing treatment; S3: After the vacuum degassing treatment is completed, heat to 90°C, keep stirring and react for 6 hours, after the reaction is completed, add 0.2 parts of hexahydroxymethylmelamine and cool to 65°C, continue stirring and keep warm for 2.5 hours, after completion, naturally cool to room temperature, filter out the product and use water and methanol to wash 3 times, then vacuum dry at 75°C overnight to obtain.

[0095] Comparative Example 5

[0096] The only difference between this comparative example and Example 1 is that the filler is a composition of polypropylene fiber and amylopectin, and the mass ratio of the two is 5:0.2.

[0097] Comparative Example 6

[0098] The only differences between this comparative example and Example 1 are as follows: the fine aggregate is river sand with an average particle size of 4.85 mm; the coarse aggregate is crushed stone with an average particle size of 32.5 mm.

[0099] Performance Evaluation

[0100] 1. The compressive strength of the concrete obtained in the embodiment and the comparative example after curing was tested with reference to the standard GB / T 50081-2019. The test results at 7d and 28d were taken, and the average value of 5 times was taken and recorded in Table 1.

[0101] 2. The maximum water penetration resistance pressure of the concrete obtained in the embodiment and the comparative example after curing was tested with reference to the standard GB / T 50082-2009. The results were expressed as the maximum no-water seepage pressure. The average value of the test values ​​was taken as 5 times and recorded in Table 1.

[0102] 3. The fixed water flow loss rate of the concrete obtained in the embodiment and the comparative example after curing was tested. The test conditions were 1.8m underwater, a water flow rate of 1.5m / s, and a time of 28 days. The loss rate of the concrete was calculated as % = concrete loss amount / total amount of concrete at the beginning of the test × 100%. The test values ​​were averaged for 5 times and recorded in Table 1.

[0103] Table 1 Performance test results

[0104]

[0105]

[0106] From the final performance test results of the embodiments and comparative examples, comparative examples 1 to 6 achieved worse performance results than the embodiments, while the embodiments took the lead in various performance aspects because they adopted the corresponding schemes defined in the present application; this is mainly because the binder system of modified resin and bisphenol A epoxy resin added in the embodiments can work together with the added filler and other formulations to greatly enhance the particle spreading effect in the concrete system, offset the agglomeration and condensation phenomenon of ultrafine particles that are easily caused by the addition of waste slurry, and thus greatly improve the integrity. After their joint action, the interconnection effect inside the concrete system is greatly enhanced, and while improving its own density and reducing the pore size of micropores, it can greatly reduce the slip effect between different phases or molecular chains and improve the mechanical properties. The barrier film layer formed inside can greatly resist the migration and penetration of water molecules in the concrete system, thereby reducing the penetration and destructive effects of the water environment on the concrete, and greatly enhancing its water resistance and water decomposition resistance.

Claims

1. A method for producing high performance concrete using waste slurry from a mixing station, characterized in that: The raw materials are: 20-35 parts of pre-treatment mixing station waste slurry, 25-40 parts of cement, 10-20 parts of binder, 8-15 parts of fly ash, 7-12 parts of slag powder, 50-60 parts of fine aggregate, 60-80 parts of coarse aggregate, 0.15-0.85 parts of water reducer, 6-8 parts of filler, 3-5.5 parts of expansion agent, 1.5-2.5 parts of antifreeze agent, and 5-14 parts of water. The solid content of the waste slurry from the pretreatment mixing station is 30-45%; The average particle size of the solid particles in the waste slurry of the pretreatment mixing station is ≤2mm and ≥0.5mm; The cement material is ordinary Portland cement or pozzolanic Portland cement; the strength grade of the cement material is 32.5 or 42.5; The adhesive is a composition of a modified resin and a bisphenol A epoxy resin; the mass ratio of the modified resin to the bisphenol A epoxy resin is (4-5): (1.2-1.5); The average particle size of the fine aggregate is 0.5 to 3.5 mm; The average particle size of the coarse aggregate is 5 to 25 mm; The filler is a composition of polypropylene fiber and pullulan; The mass ratio of the polypropylene fiber to the amylopectin is (3-3.5): (0.6-0.8); The average diameter of the polypropylene fibers is 15 to 25 μm; the average length of the polypropylene fibers is 10 to 14 mm.

2. The method for producing high performance concrete using waste slurry from a mixing station according to claim 1, characterized in that: The preparation method of the pre-treated mixing station waste slurry specifically includes the following steps: S1: collecting the mixing station waste slurry into a large storage tank, slowly stirring to maintain uniformity and prevent precipitation, and then preliminarily concentrating the mixing station waste slurry through gravity sedimentation to remove excess water and increase the solid content to 15-20%; S2: after the preliminary concentration, sending it to a plate and frame filter press or a belt filter press for further dehydration, squeezing out the water and retaining the solid particles to form a dense mud cake-like substance; S3: then performing two vibration screenings, the first screening using a 5-8 mm screen to remove large-sized impurities, the second screening using 3.5-4 mm, 2-2.5 mm and 1.2-1.8 mm screens for multi-layer graded screening, and after the screening is completed, storing the mixing station waste slurry in a special container and stirring it regularly to maintain uniformity.

3. The method for producing high performance concrete using waste slurry from a mixing station according to claim 2, characterized in that: The epoxy equivalent of the bisphenol A epoxy resin is 170-185 g / eq; the viscosity of the bisphenol A epoxy resin is 10000-15000 Da, and the test temperature is 25°C.

4. The method for producing high performance concrete using waste slurry from a mixing station according to claim 3, characterized in that: The preparation method of the modified resin specifically comprises the following steps: S1: adding vinyl-terminated polydimethylsiloxane to an organic-inorganic mixed solvent, and adding γ-glycidyloxypropyltrimethoxysilane, heating to 70-80°C, keeping the temperature for reaction for 2-3 hours, filtering out, washing and drying to obtain pretreated siloxane; S2: adding pretreated siloxane, diethyl maleate, perfluoromethyl vinyl ether and N,N-dimethylacrylamide to a toluene solvent, mixing and stirring evenly, then adding azobisisobutyronitrile and starting vacuum degassing treatment; S3: after the vacuum degassing treatment is completed, heating to 85-95°C, keeping the temperature for reaction for 4-7 hours, adding hexahydroxymethylmelamine after the reaction is completed, cooling to 60-70°C, continuing to stir and keep the temperature for reaction for 2-3 hours, and naturally cooling to room temperature after completion, filtering out the product and washing it 3-4 times with water and methanol, and then vacuum drying at 70-80°C overnight to obtain the product; The organic-inorganic mixed solvent is a mixed solvent of toluene and deionized water, and the mass ratio of toluene to deionized water is (2-3): (1-1.2).

5. The method for producing high performance concrete by using waste slurry from a mixing station according to claim 4, characterized in that: The mass ratio of the vinyl-terminated polydimethylsiloxane to γ-glycidyloxypropyltrimethoxysilane is (5-6):(0.3-0.4).

6. The method for producing high performance concrete using waste slurry from a mixing station according to claim 5, characterized in that: The mass ratio of the pretreated siloxane, diethyl maleate, perfluoromethyl vinyl ether, N,N-dimethylacrylamide and hexahydroxymethylmelamine is (15-20): (1.5-2): (2-3): (6-8): (0.4-0.5).

7. The method for producing high performance concrete using waste slurry from a mixing station according to claim 6, characterized in that: The mass ratio of the pre-treated mixing station waste slurry, cement material and water reducing agent is (25-30): (30-38): (0.15-0.45).

8. The method for producing high performance concrete by using waste slurry from a mixing station according to claim 7, characterized in that: The branch chain content of the amylopectin is 60-70%.

9. The method for producing high performance concrete using waste slurry from a mixing station according to claim 8, characterized in that: The expansion agent is a composition of calcium oxide and calcium sulfoaluminate; the mass ratio of the calcium oxide to calcium sulfoaluminate is (2.5-3.5): (1.5-2).

10. A method for producing high performance concrete using waste slurry from a mixing station according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: Add the waste slurry from the mixing station into the mixing mixer and mix evenly for later use. Then add the cement, adhesive, fly ash and slag powder into another container and mix them. Slowly add the waste slurry from the mixing station and wet mix at a speed of 30-40rpm. S2: After wet mixing for 15-20min, add the remaining raw materials, among which the filler is added after heating at 50-60℃ for 20-30min after the other raw materials are added. Make sure that all the raw materials are added and mix at a speed of 100-120rpm for 5-10min. S3: After mixing, pour at the construction site, control the slump at 160-200mm, and immediately cure under standard curing conditions after pouring, maintain appropriate temperature and humidity, and it is ready after completion.

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