Solid-waste-based large-dosage superfine fly ash anti-freezing concrete and preparation method thereof

Abstract

According to the solid-waste-based large-dosage superfine fly ash anti-freezing concrete and the preparation method thereof, high-value utilization of solid waste resources is realized through a three-stage fly ash synergistic interaction technology. The high-strength concrete is prepared from the following components in parts by weight: 50 to 55 parts by weight of superfine fly ash, 5 to 10 parts by weight of first-grade fly ash, 5 to 10 parts by weight of second-grade fly ash, 30 to 37 parts by weight of cement, 130 parts by weight of river sand, 0.33 to 0.9 part by weight of a water reducing agent and 195 parts by weight of broken stone. The method is low in manufacturing cost and simple in process, provides technical support for high-value utilization of industrial solid waste, and is suitable for the field of green low-carbon buildings.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a solid waste-based frost-resistant concrete with a large amount of ultrafine fly ash and a preparation method thereof. Background Art

[0002] As a pozzolanic material, fly ash, when properly used in concrete, can not only achieve efficient resource utilization and reduce production costs, but also improve concrete properties to a certain extent. Therefore, how to handle and utilize fly ash has become a research hotspot.

[0003] At present, fly ash concrete generally has problems such as low admixture utilization efficiency and insufficient solid waste disposal capacity. On the one hand, due to the design defects of the traditional cementitious system, the fly ash content in the existing fly ash concrete is generally small, and most of them are single-type fly ash. The utilization rate of fly ash is low, the first-level ash content is generally less than 30%, and the activity of ultrafine fly ash and the synergistic effect of graded ash are not fully utilized, resulting in a large amount of second-level and below fly ash still being mainly stockpiled, and the comprehensive utilization rate of solid waste is low. On the other hand, blindly increasing the fly ash content can easily cause problems such as fly ash particles floating up and exudation, weakening of aggregate interface, and a significant decrease in the early strength of concrete. In order to improve the mechanical properties of fly ash, activators are also added to increase the preparation cost. This "low content-low value" application model seriously restricts the large-scale disposal of solid waste and hinders the efficient resource utilization of fly ash.

[0004] Patent application CN118619625A discloses frost-resistant concrete and its preparation method. Although this invention uses solid waste materials as raw materials to prepare concrete, the amount of solid waste used is relatively small, making it impossible to recycle solid waste resources. Patent application CN105731919B discloses ultra-high fly ash content concrete. Although the fly ash content of the concrete in this invention can reach 80% of the cementitious material, the additional addition of water reducers and air entraining agents increases the preparation cost. Therefore, the present invention provides a solid waste-based, high-content, ultra-fine fly ash-resistant concrete and its preparation method. Summary of the Invention

[0005] In view of the defects of the prior art, the purpose of the present invention is to provide a solid waste-based frost-resistant concrete with a large amount of ultrafine fly ash and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] The present invention solves the technical problem by adopting the following technical solutions: The present invention provides a solid waste-based frost-resistant concrete with a large amount of ultrafine fly ash, comprising the following raw materials in parts by weight: The content of ultrafine fly ash is 50-60 parts by weight, the content of first-level fly ash is 5-15 parts by weight, the content of second-level fly ash is 5-10 parts by weight, the content of cement is 20-37 parts by weight, the content of river sand is 130 parts by weight, the content of water reducer is 0.33-0.9 parts by weight, and the content of crushed stone is 195 parts by weight.

[0007] Preferably, the cement type is PO42.5 ordinary Portland cement; the water reducer is polycarboxylate high-efficiency water reducer; and the water is ordinary domestic water.

[0008] Preferably, the fly ash is ultrafine fly ash, first-level fly ash, and second-level fly ash; the water requirement ratio of the three fly ashes is 95%-97%, and the loss on ignition is 1.5%-2%; the fineness of ultrafine fly ash is 1.5%-3% of the 45μm square hole sieve residue, and the strength activity index is 85%-90%; the fineness of first-level fly ash is 10%-12% of the 45μm square hole sieve residue, and the strength activity index is 75%-80%; the fineness of second-level fly ash is 14%-16% of the 45μm square hole sieve residue, and the strength activity index is 75%-80%.

[0009] Preferably, 4-8 parts of additives are further added to the antifreeze concrete; wherein the additives are prepared by: S1: Prepare a 5-8% by mass fraction sodium dodecylbenzenesulfonate solution, then fully blend 5-8 parts of silicon micropowder, 2-3 parts of basalt fiber, 4-7 parts of sodium dodecylbenzenesulfonate solution and 1-2 parts of silane coupling agent KH550 to obtain silicon micropowder; S2: sintering the carbon nanotubes, boron nitride, and silicon carbide in a weight ratio of 5:2:2 to obtain a carbon nanotube agent. S3: ball milling the silicon micropowder and carbon nanotubes in a weight ratio of 7:5 to obtain the first ball milling solution. The first ball milling liquid and the modified shell powder are subjected to secondary ball milling treatment in a weight ratio of 5:4. After the ball milling is completed, the additive is filtered and dried to obtain the additive.

[0010] Preferably, the sintering temperature of the blending sintering treatment is 300-350° C., and the sintering is performed for 1 hour; the ball milling speed of the primary ball milling treatment is 1250-1350 r / min, and the ball milling is performed for 2 hours; and the ball milling speed of the secondary ball milling treatment is 750-850 r / min, and the ball milling is performed for 5 hours.

[0011] The additive is blended with silicon micropowder, basalt fiber, sodium dodecylbenzenesulfonate solution and silane coupling agent, and is also improved by sintering with carbon nanotubes, boron nitride and silicon carbide, and ball milling with modified shell powder. The modified shell powder is improved by titanium dioxide through a modifying liquid, and then the shell powder liquid is blended. The additive is prepared by improving the coordination between the raw materials and enhancing the efficiency through the synergy between the raw materials, and further enhances the performance coordination and stability of the product in the system.

[0012] Preferably, the preparation method of the modified shell powder is: S11: adding titanium dioxide to a modified liquid having a volume 3-5 times the total volume of titanium dioxide and stirring the solution until the stirring is complete to obtain a modified titanium dioxide liquid; S12: Stir shell powder and sodium silicate solution in a weight ratio of 3:5 to obtain shell powder liquid, and blend the modified titanium dioxide liquid and shell powder liquid in a weight ratio of 7:5 and ball mill them for 1 hour at a ball mill speed of 1500r / min. After the ball milling is completed, filter and dry to obtain modified shell powder.

[0013] Preferably, the mass fraction of the sodium silicate solution is 5-8%; The stirring speed of the stirring treatment is 350-400 r / min, and the stirring is for 1 hour; the modified liquid includes 2-4 parts by mass of 4% yttrium nitrate solution and 1-3 parts by mass of 5% sodium alginate solution.

[0014] The present invention also provides a method for preparing solid waste-based frost-resistant concrete with a large amount of ultrafine fly ash, comprising the following steps: Step (1) cement, ultrafine fly ash, primary fly ash, secondary fly ash, and river sand are sequentially placed in a mixer and stirred until uniform to obtain mixed dry material A; Step (2) adding crushed stone and 50% of the total water, stirring until the surface of the aggregate is wetted, to obtain mixture B; Step (3) adding polycarboxylate water reducer and remaining water to obtain mixture C; Step (4) evenly apply a release agent to the inner surface of the mold, then evenly pour the mixture C into the mold, let it stand, demould it, and place it in a standard curing room for curing. After the curing is completed, a large amount of ultrafine fly ash concrete can be obtained.

[0015] Preferably, the stirring rate in step (1) is 62.5 r / min, and the stirring time is 2-3 min; the stirring rate in step (2) is 62.5 r / min, and the stirring time is 2 min; and the stirring rate in step (3) is 62.5 r / min, and the stirring time is 4-6 min.

[0016] Preferably, in step (4), the mixture C is poured into the mold in two times, and vibrated after each pouring. The total vibration time is not less than 1 min. The curing conditions in the standard curing room are: the temperature is controlled at 20±2°C, and the humidity is greater than or equal to 95%.

[0017] Compared with the prior art, the present invention has the following beneficial effects: High-value utilization of solid waste in the present invention: the total utilization rate of fly ash reaches 70%-80%; synergistic effect of multi-level fly ash: using ultrafine fly ash (50%-55%), primary fly ash (5%-10%), secondary fly ash (5%-10%) in a three-level ratio, the ultrafine ash provides pozzolanic activity, and the primary and secondary ash fills the pores; low-carbon and low-cost preparation process: the cost is relatively low, no chemical activator is required, by controlling the water-binder ratio and the dosage of polycarboxylate water reducer, the 7-day compressive strength ≥ 15 MPa and the 28-day strength ≥ 30 MPa are achieved, meeting the requirements of mechanical properties and frost resistance. Specific embodiments

[0018] The following describes the technical solutions in the embodiments of the present invention clearly and completely in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0019] A solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this embodiment includes the following raw materials in parts by weight: The content of ultrafine fly ash is 50-60 parts by weight, the content of primary fly ash is 5-15 parts by weight, the content of secondary fly ash is 5-10 parts by weight, the content of cement is 20-37 parts by weight, the river sand is 130 parts by weight, the content of water reducer is 0.33-0.9 parts by weight, and the content of crushed stone is 195 parts by weight.

[0020] The cement type in this embodiment is PO42.5 ordinary Portland cement; the water reducer is polycarboxylate superplasticizer; the water is ordinary domestic water.

[0021] The fly ash in this embodiment is ultrafine fly ash, primary fly ash, and secondary fly ash; the water demand ratios of the three fly ashes are all 95%-97%, and the loss on ignition is all 1.5%-2%; the fineness of the ultrafine fly ash is 1.5%-3% of the residue on a 45μm square hole sieve, and the strength activity index is 85%-90%; the fineness of the primary fly ash is 10%-12% of the residue on a 45μm square hole sieve, and the strength activity index is 75%-80%; the fineness of the secondary fly ash is 14%-16% of the residue on a 45μm square hole sieve, and the strength activity index is 75%-80%.

[0022] The antifreeze concrete of this embodiment is further added with 4-8 parts of an additive; wherein the additive is prepared by: S1: Prepare a 5-8% by mass fraction sodium dodecylbenzenesulfonate solution, then fully blend 5-8 parts of silicon micropowder, 2-3 parts of basalt fiber, 4-7 parts of sodium dodecylbenzenesulfonate solution and 1-2 parts of silane coupling agent KH550 to obtain silicon micropowder; S2: sintering the carbon nanotubes, boron nitride, and silicon carbide in a weight ratio of 5:2:2 to obtain a carbon nanotube agent. S3: ball milling the silicon micropowder and carbon nanotubes in a weight ratio of 7:5 to obtain the first ball milling solution. The first ball milling liquid and the modified shell powder are subjected to secondary ball milling treatment in a weight ratio of 5:4. After the ball milling is completed, the additive is filtered and dried to obtain the additive.

[0023] The sintering temperature of the blending sintering treatment in this embodiment is 300-350° C., and the sintering is performed for 1 hour. The ball milling speed of the primary ball milling treatment is 1250-1350 r / min, and the ball milling is performed for 2 hours. The ball milling speed of the secondary ball milling treatment is 750-850 r / min, and the ball milling is performed for 5 hours.

[0024] The preparation method of the modified shell powder of this embodiment is: S11: adding titanium dioxide to a modified liquid having a volume 3-5 times the total volume of titanium dioxide and stirring the solution until the stirring is complete to obtain a modified titanium dioxide liquid; S12: Stir shell powder and sodium silicate solution in a weight ratio of 3:5 to obtain shell powder liquid, and blend the modified titanium dioxide liquid and shell powder liquid in a weight ratio of 7:5 and ball mill them for 1 hour at a ball mill speed of 1500r / min. After the ball milling is completed, filter and dry to obtain modified shell powder.

[0025] The mass fraction of the sodium silicate solution in this embodiment is 5-8%; The stirring speed of the stirring treatment is 350-400 r / min, and the stirring is for 1 hour; the modified liquid includes 2-4 parts by mass of 4% yttrium nitrate solution and 1-3 parts by mass of 5% sodium alginate solution.

[0026] The method for preparing a solid waste-based frost-resistant concrete with a large amount of ultrafine fly ash in this embodiment includes the following steps: Step (1) cement, ultrafine fly ash, primary fly ash, secondary fly ash, and river sand are sequentially placed in a mixer and stirred until uniform to obtain mixed dry material A; Step (2) adding crushed stone and 50% of the total water, stirring until the surface of the aggregate is wetted, to obtain mixture B; Step (3) adding polycarboxylate water reducer and remaining water to obtain mixture C; Step (4): Uniformly apply a mold release agent to the inner surface of the mold, then uniformly pour the mixture C into the mold, let it stand, demold, and place it in a standard curing room for curing. After the curing is completed, high-volume ultra-fine fly ash concrete can be obtained.

[0027] In step (1) of this embodiment, the stirring rate is 62.5 r / min and the stirring time is 2 - 3 min; in step (2), the stirring rate is 62.5 r / min and the stirring time is 2 min; in step (3), the stirring rate is 62.5 r / min and the stirring time is 4 - 6 min.

[0028] In step (4) of this embodiment, the mixture C is poured into the mold in two times, and each time after pouring, it is vibrated, and the total vibration time is not less than 1 min; the curing conditions in the standard curing room are: the temperature is controlled at 20 ± 2 °C and the humidity is greater than or equal to 95%.

[0029] Example 1. The solid waste-based high-volume ultra-fine fly ash frost-resistant concrete of this embodiment is composed of the following components in parts by weight: 55 parts of ultra-fine fly ash, 10 parts of grade I fly ash, 5 parts of grade II fly ash, 30 parts of cement, 130 parts of river sand, 195 parts of crushed stone, 35 parts of mixing water, 0.9 part of water reducer; among them, for ultra-fine fly ash, grade I fly ash, and grade II fly ash, the water demand ratios of the three fly ashes are all 95% - 97%, and the loss on ignition is all 1.5% - 2%. The fineness of the ultra-fine fly ash is 1.5% - 3% of the residue on the 45 μm square hole sieve, and the strength activity index is 85% - 90%; the fineness of the grade I fly ash is 10% - 12% of the residue on the 45 μm square hole sieve, and the strength activity index is 75% - 80%; the fineness of the grade II fly ash is 14% - 16% of the residue on the 45 μm square hole sieve, and the strength activity index is 75% - 80%; the cement is PO42.5 ordinary Portland cement; the river sand is standard river sand with a particle size less than 4.7 mm; the crushed stone is 5 - 20 mm continuous grading crushed stone; the water is ordinary domestic water; the water reducer is a pure water-reducing type water reducer produced by Shanxi Feike New Materials Technology Co., Ltd.; 6 parts of additives are also added to the frost-resistant concrete.

[0030] The preparation method of the solid waste-based high-volume ultra-fine fly ash frost-resistant concrete of this embodiment includes the following steps: Step (1): Put 30 parts of cement, 55 parts of ultra-fine fly ash, 10 parts of grade I fly ash, 5 parts of grade II fly ash, 130 parts, and 6 parts of additives (river sand) into the mixer in sequence, and stir at a rate of 62.5 r / min for 2 - 3 min until uniform to obtain mixture A.

[0031] Step (2): Add 195 parts of crushed stone and 17.5 parts of water to the mixer, and stir at a rate of 62.5 r / min for 2 min to obtain mixture B.

[0032] Step (3), add 0.9 parts of water reducer and 17.5 parts of water to obtain mixture C.

[0033] Step (4): evenly apply a release agent to the inner surface of the mold, and then pour the mixture C into the mold twice. After each pouring, vibrate it for a total vibration time of not less than 1 minute, let it stand, demould it, and put it into a standard curing room for curing. The curing conditions of the standard curing room are: temperature controlled at 20±2℃, humidity greater than or equal to 95%. After curing to the specified age, take it out to obtain solid waste-based high-volume ultrafine fly ash antifreeze concrete.

[0034] The preparation method of the additive is: S1: Prepare a 6.5% mass fraction of sodium dodecylbenzenesulfonate solution, then fully blend 6.5 parts of silicon micropowder, 2.5 parts of basalt fiber, 5.5 parts of sodium dodecylbenzenesulfonate solution and 1.5 parts of silane coupling agent KH550 to obtain silicon micropowder; S2: sintering the carbon nanotubes, boron nitride, and silicon carbide in a weight ratio of 5:2:2 to obtain a carbon nanotube agent. S3: ball milling the silicon micropowder and carbon nanotubes in a weight ratio of 7:5 to obtain the first ball milling solution. The first ball milling liquid and the modified shell powder are subjected to secondary ball milling treatment in a weight ratio of 5:4. After the ball milling is completed, the additive is filtered and dried to obtain the additive.

[0035] The sintering temperature of the blending sintering treatment in this embodiment is 325° C., and the sintering is performed for 1 hour. The ball milling speed of the primary ball milling treatment is 1300 r / min, and the ball milling is performed for 2 hours. The ball milling speed of the secondary ball milling treatment is 800 r / min, and the ball milling is performed for 5 hours.

[0036] The preparation method of the modified shell powder of this embodiment is: S11: adding titanium dioxide to a modified liquid having a volume 4 times the total volume of titanium dioxide and stirring the mixture until the stirring is complete to obtain a modified titanium dioxide liquid; S12: Stir shell powder and sodium silicate solution in a weight ratio of 3:5 to obtain shell powder liquid, and blend the modified titanium dioxide liquid and shell powder liquid in a weight ratio of 7:5 and ball mill them for 1 hour at a ball mill speed of 1500r / min. After the ball milling is completed, filter and dry to obtain modified shell powder.

[0037] The mass fraction of the sodium silicate solution in this embodiment is 6.5%; The stirring speed of the stirring treatment is 370 r / min, and the stirring is performed for 1 hour; the modified liquid includes 3 parts of 4% by mass yttrium nitrate solution and 2 parts of 5% by mass sodium alginate solution.

[0038] In order to test the mechanical properties and frost resistance of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete prepared in the examples, the casting molds used in this example are 100mm×100mm×100mm and 100mm×100mm×400mm, and the strength of the 150mm standard specimens in actual engineering is correlated through a conversion coefficient (0.95). According to the test methods specified in the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), the compressive property test is carried out, and the compressive strength tests are carried out on the compressive specimens with curing ages of 7d and 28d respectively. The frost resistance test is carried out on the frost-resistant specimens after the curing age of 28d.

[0039] Example 2. The solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example is composed of the following components in parts by weight: 53 parts of ultrafine fly ash, 5 parts of first-class fly ash, 5 parts of second-class fly ash, 37 parts of cement, 130 parts of river sand, 195 parts of crushed stone, 44 parts of mixing water, 0.4 parts of water reducer and 5 parts of additive.

[0040] The preparation method of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example and the preparation method of the additive are the same as those in Example 1.

[0041] The size of the casting mold for the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example, the compressive strength test and the frost resistance test method are the same as those in Example 1.

[0042] Example 3. The solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example is composed of the following components in parts by weight: 60 parts of ultrafine fly ash, 5 parts of first-class fly ash, 10 parts of second-class fly ash, 25 parts of cement, 130 parts of river sand, 195 parts of crushed stone, 38 parts of mixing water, 0.5 parts of water reducer and 8 parts of additive.

[0043] The preparation method of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example and the preparation method of the additive are the same as those in Example 1.

[0044] The size of the casting mold for the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example and the compressive strength test method are the same as those in Example 1.

[0045] Example 4. The solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example is composed of the following components in parts by weight: 60 parts of ultrafine fly ash, 15 parts of first-class fly ash, 5 parts of second-class fly ash, 20 parts of cement, 130 parts of river sand, 195 parts of crushed stone, 35 parts of mixing water, 0.33 parts of water reducer and 8 parts of additive.

[0046] The preparation method of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this example and the preparation method of the additive are the same as those in Example 1.

[0047] The mold dimensions for casting the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in this embodiment, as well as the test methods for compressive strength and frost resistance performance, are the same as those in Example 1.

[0048] After testing, the compressive strengths of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in Examples 1 to 4 are shown in Table 1.

[0049]

[0050] As can be seen from Table 1, the 7-day compressive strength of the concrete of the present invention is 16.2 - 24 MPa, and the 28-day strength is ≥ 30 MPa. The solid waste-based high-volume ultrafine fly ash frost-resistant concrete of the present invention has good strength development characteristics. At the age of 7 days, the strength range covers 16.3 - 24 MPa, which can meet the engineering scenarios with certain requirements for early strength; the 28-day strength is stable at ≥ 30 MPa, indicating significant late strength growth and stable performance, which can effectively ensure the long-term load-bearing capacity of the structure. This strength development law benefits from the unique raw material ratio and process of high-volume solid waste-based and ultrafine fly ash, providing reliable performance support for the application of concrete in various frost-resistant projects. Compared with traditional concrete, it has outstanding advantages in resource utilization and performance.

[0051] After testing, the frost resistance performance data of the solid waste-based high-volume ultrafine fly ash frost-resistant concrete in Examples 1 to 4 are shown in Table 2.

[0052]

[0053] As can be seen from Table 2, after 150 freeze-thaw cycles, the mass loss rate of the specimens of Example 4 is higher than 5%, and the relative dynamic elastic modulus is lower than 60%. After 200 freeze-thaw cycles, the mass loss rate of the specimens of Example 3 is higher than 5%, and the relative dynamic elastic modulus is lower than 60%. According to the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" and the "Code for Durability Design of Concrete Structures in Highway Engineering", the number of freeze-thaw cycles of Example 4 exceeds 100 times, and the environmental action level belongs to D3 (general freeze-thaw), meeting the F100 standard, and is applicable to ordinary building structures with certain durability requirements (such as civil building foundations, general industrial plant floors). The number of freeze-thaw cycles of Example 3 exceeds 150 times, and the environmental action level belongs to D4 (severe freeze-thaw), meeting the F150 standard, and is applicable to important structures in cold regions; the number of freeze-thaw cycles of Examples 1 and 2 exceeds 200 times, and the environmental action level belongs to D4 (severe freeze-thaw), meeting the F200 standard, and is applicable to structures in severe cold regions or with high durability requirements (such as dams, bridges). Therefore, overall, the performance of the solid waste-based high-volume ultra-fine fly ash frost-resistant concrete of the present invention in freeze-thaw cycles shows high durability and reliability, and can meet the frost resistance requirements in practical engineering applications. Although the performance of some examples decreases at lower cycle numbers, overall, its frost resistance performance is still excellent. The fly ash content of the concrete of the present invention reaches more than 70% of the cementitious material, which can greatly reduce the material cost, and is more in line with the environmental protection concept of solid waste resource reuse. At the same time, a three-level ratio of ultra-fine fly ash, class I fly ash, and class II fly ash is adopted to reinforce the solid waste-based high-volume ultra-fine fly ash frost-resistant concrete, which not only reduces the manufacturing cost of the concrete, but also ensures the corresponding construction performance and service performance. The preparation process flow is simple, the operation is convenient and does not require expensive equipment, achieving low cost and low energy consumption, and is suitable for large-scale popularization and application in practical engineering.

[0054] The above has introduced in detail a solid waste-based high-volume ultra-fine fly ash frost-resistant concrete and its preparation method provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above examples is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, based on the idea of the present application, other different forms of changes can be made on the basis of the above description. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A solid waste-based high-volume ultrafine fly ash frost-resistant concrete, characterized in that, It includes the following raw materials in parts by weight: The content of ultrafine fly ash is 50-60 parts by weight, the content of first-level fly ash is 5-15 parts by weight, the content of second-level fly ash is 5-10 parts by weight, the content of cement is 20-37 parts by weight, the content of river sand is 130 parts by weight, the content of water reducer is 0.33-0.9 parts by weight, and the content of crushed stone is 195 parts by weight.

2. The antifreeze concrete made from solid waste-based high-volume ultrafine fly ash according to claim 1, characterized in that, The cement model is PO42.5 ordinary Portland cement; the water reducer is polycarboxylic acid high-efficiency water reducer; and the water is ordinary domestic water.

3. A waste-based high-volume ultrafine fly ash frost-resistant concrete according to claim 1, characterized in that, The fly ash includes ultrafine fly ash, first-grade fly ash and second-grade fly ash; the water requirement ratio of the three fly ashes is 95%-97%, and the loss on ignition is 1.5%-2%; the fineness of ultrafine fly ash is 1.5%-3% of the 45μm square hole sieve residue, and the strength activity index is 85%-90%; the fineness of first-grade fly ash is 10%-12% of the 45μm square hole sieve residue, and the strength activity index is 75%-80%; the fineness of second-grade fly ash is 14%-16% of the 45μm square hole sieve residue, and the strength activity index is 75%-80%.

4. A solid waste-based high-volume ultra-fine fly ash frost-resistant concrete according to claim 1, characterized in that, 4-8 parts of additives are also added to the antifreeze concrete; wherein the additives are prepared by: S1: Prepare a 5-8% by mass fraction sodium dodecylbenzenesulfonate solution, then fully blend 5-8 parts of silicon micropowder, 2-3 parts of basalt fiber, 4-7 parts of sodium dodecylbenzenesulfonate solution and 1-2 parts of silane coupling agent KH550 to obtain silicon micropowder; S2: sintering the carbon nanotubes, boron nitride, and silicon carbide in a weight ratio of 5:2:2 to obtain a carbon nanotube agent. S3: ball milling the silicon micropowder and carbon nanotubes in a weight ratio of 7:5 to obtain the first ball milling solution. The first ball milling liquid and the modified shell powder are subjected to secondary ball milling treatment in a weight ratio of 5:

4. After the ball milling is completed, the additive is filtered and dried to obtain the additive.

5. A solid waste-based high-volume ultrafine fly ash frost-resistant concrete according to claim 4, characterized in that, The sintering temperature of the blending sintering treatment is 300-350° C., and the sintering is performed for 1 hour. The ball milling speed of the first-stage ball milling treatment is 1250-1350 r / min, and the ball milling is performed for 2 hours. The ball milling speed of the second-stage ball milling treatment is 750-850 r / min, and the ball milling is performed for 5 hours.

6. A solid waste-based high-volume ultra-fine fly ash antifreeze concrete according to claim 4, characterized in that, The preparation method of the modified shell powder is: S11: adding titanium dioxide to a modified liquid having a volume 3-5 times the total volume of titanium dioxide and stirring the solution until the stirring is complete to obtain a modified titanium dioxide liquid; S12: Stir shell powder and sodium silicate solution in a weight ratio of 3:5 to obtain shell powder liquid, and blend the modified titanium dioxide liquid and shell powder liquid in a weight ratio of 7:5 and ball mill them for 1 hour at a ball mill speed of 1500r / min. After the ball milling is completed, filter and dry to obtain modified shell powder.

7. A solid waste-based high-volume ultra-fine fly ash antifreeze concrete according to claim 6, characterized in that, The mass fraction of the sodium silicate solution is 5-8%; The stirring speed of the stirring treatment is 350-400 r / min, and the stirring is for 1 hour; the modified liquid includes 2-4 parts by mass of 4% yttrium nitrate solution and 1-3 parts by mass of 5% sodium alginate solution.

8. The preparation method of a solid waste-based high-volume ultrafine fly ash frost-resistant concrete according to any one of claims 1-7, characterized in that, The following steps are involved: Step (1) cement, ultrafine fly ash, primary fly ash, secondary fly ash, and river sand are sequentially placed in a mixer and stirred until uniform to obtain mixed dry material A; In step (2), add crushed stone and 50% of the total water amount, and stir until the surface of the aggregate is wetted to obtain mixture B; In step (3), add polycarboxylate water reducer and the remaining water to obtain mixture C; In step (4), evenly apply a mold release agent to the inner surface of the mold, then evenly pour mixture C into the mold, let it stand, demold, and place it in a standard curing room for curing. After the curing is completed, high-volume ultrafine fly ash concrete can be obtained.

9. The preparation method of a solid waste-based high-volume ultrafine fly ash frost-resistant concrete according to claim 8, characterized in that, The stirring rate in step (1) is 62.5 r / min, and the stirring time is 2 - 3 min; the stirring rate in step (2) is 62.5 r / min, and the stirring time is 2 min; the stirring rate in step (3) is 62.5 r / min, and the stirring time is 4 - 6 min.

10. The preparation method of a solid waste-based high-volume ultrafine fly ash frost-resistant concrete according to claim 8, characterized in that, In step (4), mixture C is poured into the mold in two times, and it is vibrated after each pouring. The total vibration time is not less than 1 min; the curing conditions in the standard curing room are: the temperature is controlled at 20 ± 2 °C, and the humidity is greater than or equal to 95%.

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