Self-compacting shrinkage-compensating concrete and preparation method thereof

Abstract

The invention relates to the technical field of concrete, and particularly discloses self-compacting shrinkage-compensating concrete and a preparation method thereof. The self-compacting shrinkage-compensating concrete is prepared from the following raw materials in parts by weight: 160 to 170 parts of water, 395 to 415 parts of cement, 635 to 655 parts of sand, 1000 to 1040 parts of gravel, 60 to 70 parts of fly ash, 5.4 to 5.7 parts of an additive, 80 to 90 parts of mineral powder, 45 to 55 parts of steel fiber, 40 to 48 parts of an expanding agent and 20 to 25 parts of a modified functional material, the preparation method comprises the following steps: stirring and mixing the sand and the gravel, then adding the cement, the fly ash and the mineral powder, stirring and mixing, then adding the water and the additive, stirring and mixing, and finally adding the steel fiber, the expanding agent and the modified functional material, and stirring and mixing. The self-compacting shrinkage-compensating concrete provided by the invention can keep better structural stability in the application process of the coastal region under strong wind.

Description

Technical Field

[0001] This application relates to the field of concrete technology, and more specifically, to a self-compacting shrinkage-compensating concrete and a method for preparing the same. Background Technology

[0002] Self-compacting shrinkage-compensating concrete refers to concrete that can flow and compact under its own weight, completely filling the formwork even with dense reinforcement, while achieving excellent homogeneity and requiring no additional vibration. By incorporating an expansion agent, the concrete undergoes micro-expansion during the hardening process, thereby compensating for shrinkage and reducing crack formation. It is suitable for various engineering scenarios requiring high strength, durability, and crack resistance, and is widely used in structures such as long-span steel arch bridges and steel-concrete composite bridges.

[0003] The main raw materials for self-compacting shrinkage-compensating concrete include: cement, fly ash, ground granulated slag powder, fine aggregate, coarse aggregate, water-reducing agent, expanding agent, and mixing water. Cement, as the main cementitious material, is the basic component of concrete, providing the necessary bonding force and strength. Fly ash and slag powder, as mineral admixtures, can improve the fluidity and durability of concrete while reducing cement usage and lowering costs. Fine and coarse aggregates affect the density and fluidity of concrete. Water-reducing agents improve the fluidity and stability of concrete by optimizing the water-cement ratio and enhancing cohesion. Expanding agents, such as calcium sulfoaluminate expanders, can form ettringite in concrete, promoting concrete expansion and compensating for shrinkage. Mixing water participates in the hydration reaction, forming the structure of the concrete.

[0004] When self-compacting shrinkage-compensating concrete is applied to the crossbeams of rib arch bridges, the crossbeams, as an important component of the rib arch bridge, need to withstand the lateral forces from the arch ribs. In coastal areas, due to the influence of ocean monsoons, the air contains a large amount of salt, and strong winds will exert a large wind pressure on the crossbeams, causing the salt to quickly penetrate into the concrete and react with the hydration products of the cement to generate expansive corrosion products, resulting in rapid and severe corrosion. This leads to deformation or damage of the self-compacting shrinkage-compensating concrete structure, affecting its service life.

[0005] Therefore, there is an urgent need to propose a solution to address the aforementioned technical problems. Summary of the Invention

[0006] To improve the resistance of self-compacting shrinkage-compensating concrete to salt erosion under strong winds in coastal areas, this application provides a self-compacting shrinkage-compensating concrete and its preparation method.

[0007] Firstly, this application provides a self-compacting shrinkage-compensating concrete, employing the following technical solution: A self-compacting shrinkage-compensating concrete is made from raw materials comprising the following parts by weight: 160-170 parts water; 395-415 parts cement; 635-655 parts of sand; 1000-1040 parts of crushed stone; 60-70 parts fly ash; 5.4-5.7 parts of admixture; 80-90 parts of mineral powder; 45-55 parts steel fiber; 40-48 parts of expanding agent; 20-25 parts of modified functional material; The modified functional material is prepared through the following steps: S1. After preheating the mica powder raw material, disperse it in water to form a suspension. Then add cerium salt solution and stir to mix. Next, add precipitant to react. After the reaction is completed, filter to obtain a solid product. Dry the solid product and calcine it to obtain pretreated mica powder. S2. The pretreated mica powder from step S1 is placed in a dilute phytic acid solution, ultrasonically mixed, and then aniline monomer and ammonium persulfate are added and stirred to react. After the reaction is completed, the solid product is obtained by filtration. The solid product is washed, dried and ground to obtain the modified functional material.

[0008] By adopting the above technical solution, in the preparation of modified functional materials, the mica powder raw material can be uniformly dispersed by forming a suspension. After adding cerium salt solution, hydrated cerium oxide is directionally grown on the mica surface under the action of a precipitant. After subsequent calcination treatment, the amorphous cerium oxide is transformed into a cubic fluorite structure, and composite particles of mica powder and cerium oxide are obtained, which are called pretreated mica powder. Then, aniline monomer is added to the pretreated mica powder in a phytic acid environment, and the aniline monomer is polymerized under the action of ammonium persulfate initiator, thereby growing on the surface of the pretreated mica powder to form polymer polyaniline, and finally obtaining the modified functional material. When the aforementioned modified functional materials are used as raw materials in self-compacting shrinkage-compensating concrete, firstly, the layered silicate structure of mica can form a multi-level, staggered layered distribution within the concrete, effectively blocking the intrusion of salt under strong winds. Secondly, cerium oxide possesses oxygen vacancy defects, which can consume corrosive ions, reducing the diffusion of salt within the concrete and thus slowing down the expansion and damage of ettringite. Finally, polyaniline can not only effectively inhibit the penetration and migration of corrosive media such as chloride and sulfate ions, but also reduce the expansion stress caused by the expansionary corrosion products generated by salt erosion. Through the synergistic compounding of these three components, the modified functional materials can significantly reduce salt erosion under strong winds in coastal areas and greatly eliminate the adverse effects of salt erosion, thereby enabling the self-compacting shrinkage-compensating concrete to maintain excellent structural stability during application.

[0009] Preferably, in step S1 of preparing the modified functional material, the solid content of the mica powder raw material in the suspension is 10-15%, the concentration of the cerium salt solution is 0.5-1 mol / L, and the mass mixing ratio of the suspension and the cerium salt solution is (3-5):1.

[0010] By adopting the above technical solution, the parameters control and balance the dispersibility and reactivity of mica powder, ensuring that a uniform coating layer is formed after the addition of the precipitant, thus enabling Ce... 3+ The mica powder surface is fully covered, and after calcination, a uniform, dense, and highly adhesive nano-CeO2 layer is formed, ensuring that the mica powder and cerium oxide can form a stable bond and exert excellent synergistic effects in the final modified functional material.

[0011] Preferably, in step S2 of preparing the modified functional material, the weight ratio of pretreated mica powder to aniline monomer is (1-1.4):1.

[0012] By adopting the above technical solution, when the proportion of mica powder is too high, the amount of aniline monomer is insufficient, which cannot completely cover the active sites on the surface of the pretreated mica, resulting in a discontinuous polyaniline coating layer. When the proportion of mica powder is too low, the amount of aniline monomer is too high, and some monomers polymerize homogeneously in the solution, generating free polyaniline particles instead of heterogeneous nucleation on the mica surface. Free polyaniline will degrade the mechanical properties of concrete. The above-mentioned proportion of mica powder and aniline monomer can ensure that the aniline monomer reacts fully with the active sites on the mica surface to form a uniform, dense, and high-bonding-strength polyaniline structure, while avoiding the generation of free polyaniline, so that the final modified functional material can exert a more excellent and stable corresponding effect.

[0013] Preferably, the particle size of the modified functional material is 200-800 mesh.

[0014] By adopting the above technical solution, the modified functional materials with the above particle size can avoid rapid settling or floating in application, ensuring that the modified functional materials are evenly distributed in the slurry, and can effectively fill the micron-level pores between cement stone and coarse aggregate, thereby playing an excellent role in improving the ability of self-compacting shrinkage-compensating concrete to resist salt erosion under strong winds in coastal areas.

[0015] Preferably, the raw materials also contain 10-15 parts by weight of functional additives, which are composed of elastic fibers and porous ceramic powder, and the weight ratio of elastic fibers to porous ceramic powder is (2.4-3.2):1.

[0016] By adopting the above technical solutions, elastic fibers form a spatial network structure during the hardening process of concrete, effectively inhibiting plastic shrinkage cracks. Under the salt corrosion wet-dry cycle environment, their high elastic modulus and high ductility can restrain the propagation of microcracks caused by the expansive corrosion products generated by salt erosion, delaying crack penetration. Porous ceramic powder fills capillary pores and adsorbs salt solutions; its microporous structure can temporarily trap infiltrated chloride and sulfate ions, reducing their migration into the concrete interior. When elastic fibers and porous ceramic powder are used as functional additives in appropriate weight ratios, they can exert excellent synergistic effects, improving matrix density and refining pores, forming a protective mechanism of elastic fiber crack control and porous ceramic powder salt control, thereby significantly improving the salt erosion resistance of self-compacting shrinkage-compensating concrete under strong winds in coastal areas. At the same time, the functional additives can also complement the modified functional materials in terms of their mechanism of action, forming a synergistic effect, enabling self-compacting shrinkage-compensating concrete to maintain better structural stability during application.

[0017] Preferably, the weight ratio of the elastic fiber to the porous ceramic powder is 2.8:1.

[0018] By adopting the above technical solution, the elastic fibers and porous ceramic powder in the above proportion can form a relatively uniformly distributed compound system in the self-compacting shrinkage-compensating concrete structural system, thereby bringing about better application improvement effect.

[0019] Preferably, the elastic fiber has a length of 6-18 mm and a diameter of 10-20 μm; the porous ceramic powder has a particle size of 5-10 mm, a porosity of 30-40%, and a pore size of 45-55 μm.

[0020] By adopting the above technical solution, the elastic fibers of the above specifications can provide better stress dispersion and exhibit strong interfacial adhesion to the cement matrix, thus having a better restraint rate against the expansive corrosion products caused by salt erosion; the porous ceramic powder of the above specifications can form a capillary network, preferentially adsorb the infiltrated salt solution, and extend the salt penetration path through surface micropores, thus exhibiting better resistance to salt erosion under strong winds; in this way, the corresponding effects brought about by the application of functional additives are better.

[0021] Preferably, the weight ratio of the modified functional material to the functional additive is 22:13.

[0022] By adopting the above technical solution, when the modified functional materials and functional additives of the above proportion are applied to self-compacting shrinkage-compensating concrete, the mechanisms of action of the two can form a more synergistic combination, thereby achieving a better 1+1>2 improvement effect, which is conducive to obtaining self-compacting shrinkage-compensating concrete with better application quality.

[0023] Secondly, this application provides a method for preparing self-compacting shrinkage-compensating concrete, employing the following technical solution: A method for preparing self-compacting shrinkage-compensating concrete includes the following steps: (1) Prepare raw materials including water, cement, sand, crushed stone, fly ash, admixtures, mineral powder, steel fiber, expansion agent and modified functional material according to the proportion; (2) After mixing the sand and gravel in step (1), add cement, fly ash and mineral powder and mix. Then add water and admixtures and mix. Finally add steel fiber, expansion agent and modified functional material and mix to obtain self-compacting shrinkage-compensating concrete.

[0024] By adopting the above technical solution, the above operation method is relatively simple. The raw materials are added and mixed in steps, which not only makes it easy to control the quality during the process, but also ensures that the raw materials can be fully combined to exert their corresponding effects, thereby obtaining self-compacting shrinkage-compensating concrete of better quality. It is also more suitable for large-scale industrial production.

[0025] In summary, this application has the following beneficial effects: 1. This application uses specially prepared modified functional materials in self-compacting shrinkage-compensating concrete. Through the synergistic compounding of mica, cerium oxide and polyaniline in the modified functional materials, the salt erosion under strong winds in coastal areas can be significantly reduced and the adverse effects of salt erosion can be greatly eliminated. Thus, the self-compacting shrinkage-compensating concrete can maintain relatively excellent structural stability during application. 2. This application uses a functional additive composed of elastic fibers and porous ceramic powder. Through the synergistic effect of the elastic fibers and porous ceramic powder, it not only restrains the propagation of microcracks caused by the expansion of corrosion products due to salt erosion, but also reduces the migration of salt into the concrete. This forms a protective mechanism of crack control by elastic fibers and salt control by porous ceramic powder. In conjunction with the modified functional material, it can significantly improve the salt erosion resistance of self-compacting shrinkage-compensating concrete under strong winds in coastal areas. Detailed Implementation

[0026] The present application will be further described in detail below with reference to preparation examples, embodiments and comparative examples.

[0027] Unless otherwise specified, all raw materials used in the preparation examples, embodiments and comparative examples of this application are commercially available.

[0028] The cement was purchased from Jinfeng PO425. The sand was purchased from Weijin Concrete's manufactured medium sand. The crushed stone was purchased from Jiujiang Jintuo, with a specification of 5-25mm. The fly ash was purchased from Huatai Class C, Grade II. The admixture is ZWL-A-IX high-performance water-reducing agent; The mineral powder was purchased from Baotian S95 grade. The expansion agent was purchased from Denki Chemical's HP-CSA concrete expansion agent in Japan. The elastic fiber was purchased from polyacrylonitrile fiber from Shandong Hengtai New Material Technology Co., Ltd. The porous ceramic powder is porous silicon carbide ceramic powder, purchased from Qingzhou Xinxin Silicon Industry Technology Co., Ltd.

[0029] Preparation examples of raw materials and / or intermediates Preparation Example 1 A modified functional material is prepared by the following steps: S1. Take mica powder raw material, preheat it at 70℃ for 10 min, disperse it in water to form a suspension, then add cerium salt solution and stir at 75℃. Then add 0.1 mol / L oxalic acid solution as a precipitant and react for 2.5 h. The oxalic acid solution is added at a rate of 4 mL / min and the weight of the oxalic acid solution used is 20% of the total weight of the suspension and cerium salt solution. After the reaction is completed, filter to obtain a solid product. After drying the solid product, calcine it at 650℃ for 3 h to obtain pretreated mica powder. S2. The pretreated mica powder from step S1 is placed in a 15% phytic acid dilute solution at a ratio of 1 mg: 1 mL. After ultrasonic mixing, aniline monomer and ammonium persulfate are added and stirred for 8 hours. The molar ratio of ammonium persulfate to ammonium persulfate is 1:1. After the reaction is completed, the solid product is obtained by vacuum filtration. The solid product is washed, dried and ground to obtain the modified functional material.

[0030] Note: In step S1, the solid content of the mica powder raw material in the suspension is 12.5%, the concentration of the cerium salt solution is 0.75 mol / L, and the mass mixing ratio of the suspension and the cerium salt solution is 4:1. In step S2, the weight ratio of pretreated mica powder to aniline monomer is 1.2:1. The particle size of the modified functional material is 500 mesh.

[0031] Preparation Example 2 A modified functional material differs from Preparation Example 1 in that, in step S1, the mica powder raw material solid content in the suspension is 10%, the concentration of the cerium salt solution is 0.5 mol / L, and the mass mixing ratio of the suspension and the cerium salt solution is 3:1.

[0032] Preparation Example 3 A modified functional material differs from Preparation Example 1 in that, in step S1, the solid content of mica powder raw material in the suspension is 15%, the concentration of cerium salt solution is 1 mol / L, and the mass mixing ratio of suspension and cerium salt solution is 5:1.

[0033] Preparation Example 4 A modified functional material differs from Preparation Example 1 in that, in step S2, the weight ratio of pretreated mica powder to aniline monomer is 1:1.

[0034] Preparation Example 5 A modified functional material differs from Preparation Example 1 in that, in step S2, the weight ratio of pretreated mica powder to aniline monomer is 1.4:1.

[0035] Preparation Example 6 A modified functional material differs from Preparation Example 1 in that the particle size of the modified functional material is 200 mesh.

[0036] Preparation Example 7 A modified functional material differs from Preparation Example 1 in that the particle size of the modified functional material is 800 mesh.

[0037] Preparation Example 8 A modified functional material, differing from preparation example 1, is prepared by the following steps: Mica powder raw material was preheated at 70℃ for 10 min and then dispersed in water to form a suspension. Cerium salt solution was then added and stirred at 75℃. Next, 0.1 mol / L oxalic acid solution was added as a precipitant and reacted for 2.5 h. The oxalic acid solution was added at a rate of 4 mL / min and the weight of the oxalic acid solution used was 20% of the total weight of the suspension and cerium salt solution. After the reaction was completed, the solid product was obtained by filtration. The solid product was dried and then calcined at 650℃ for 3 h to obtain the modified functional material.

[0038] Preparation Example 9 A modified functional material, differing from preparation example 1, is prepared by the following steps: Mica powder raw material was placed in a 15% phytic acid dilute solution at a ratio of 1 mg: 1 mL. After ultrasonic mixing, aniline monomer and ammonium persulfate were added and stirred for 8 hours. The molar ratio of ammonium persulfate to ammonium persulfate was 1:1. After the reaction was completed, the solid product was obtained by vacuum filtration. The solid product was washed, dried and ground to obtain the modified functional material. Example

[0039] Example 1 A self-compacting shrinkage-compensating concrete, the raw materials used in its preparation and their corresponding weight parts are shown in Table 1, and it is prepared through the following steps: (1) Prepare raw materials including water, cement, sand, crushed stone, fly ash, admixtures, mineral powder, steel fiber, expansion agent and modified functional material according to the proportion; (2) After mixing the sand and gravel in step (1), add cement, fly ash and mineral powder and mix. Then add water and admixtures and mix. Finally add steel fiber, expansion agent and modified functional material and mix to obtain self-compacting shrinkage-compensating concrete.

[0040] Note: In the above operations, the modified functional material was obtained from Preparation Example 1.

[0041] Example 2-3 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the raw materials used in its preparation and their corresponding weight parts are shown in Table 1.

[0042] Table 1. Raw materials used in the preparation of Examples 1-3 and their corresponding weight parts (parts / kg) raw material Example 1 Example 2 Example 3 water 165 160 170 cement 405 395 415 sand 645 635 655 gravel 1020 1000 1040 fly ash 65 60 70 admixtures 5.55 5.4 5.7 Mineral powder 85 80 90 steel fiber 50 45 55 Expanding agent 44 40 48 Modified functional materials 22.5 20 25 Example 4 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 2.

[0043] Example 5 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 3.

[0044] Example 6 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 4.

[0045] Example 7 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 5.

[0046] Example 8 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 6.

[0047] Example 9 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 7.

[0048] Example 10 A self-compacting shrinkage-compensating concrete differs from Example 1 in that 12.5 parts by weight of functional additives are added to the raw materials. The functional additives are composed of elastic fibers and porous ceramic powder in a weight ratio of 2.8:1, and the functional additives are added together with the modified functional materials.

[0049] The elastic fiber has a length of 12 mm and a diameter of 15 μm; the porous ceramic powder has a particle size of 7.5 mm, a porosity of 35%, and a pore size of 50 μm.

[0050] Example 11 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the functional additive is added in 10 parts by weight.

[0051] Example 12 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the functional additive is added in 15 parts by weight.

[0052] Example 13 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the functional additive is composed of elastic fibers and porous ceramic powder in a weight ratio of 2.4:1.

[0053] Example 14 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the functional additive is composed of elastic fibers and porous ceramic powder in a weight ratio of 3.2:1.

[0054] Example 15 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the elastic fiber has a length of 6 mm and a diameter of 10 μm; the porous ceramic powder has a particle size of 5 mm, a porosity of 30%, and a pore size of 45 μm.

[0055] Example 16 A self-compacting shrinkage-compensating concrete differs from Example 10 in that the elastic fiber has a length of 18 mm and a diameter of 20 μm; the porous ceramic powder has a particle size of 10 mm, a porosity of 40%, and a pore size of 55 μm.

[0056] Example 17 A self-compacting shrinkage-compensating concrete differs from Example 10 in that elastic fibers are not used in the raw materials.

[0057] Example 18 A self-compacting shrinkage-compensating concrete differs from Example 10 in that porous ceramic powder is not used in the raw materials.

[0058] Comparative Example Comparative Example 1 A self-compacting shrinkage-compensating concrete differs from Example 1 in that no modified functional materials are used in the raw materials.

[0059] Comparative Example 2 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional materials are replaced by mica powder raw materials.

[0060] Comparative Example 3 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 8.

[0061] Comparative Example 4 A self-compacting shrinkage-compensating concrete differs from Example 1 in that the modified functional material is obtained from Preparation Example 9.

[0062] Comparative Example 5 A self-compacting shrinkage-compensating concrete differs from Example 10 in that no modified functional materials are used in the raw materials.

[0063] Performance testing test samples: The self-compacting shrinkage-compensating concrete obtained in Examples 1-18 was selected as test sample 1-18, and the self-compacting shrinkage-compensating concrete obtained in Comparative Examples 1-5 was selected as control sample 1-5.

[0064] Test method: The test uses block samples with dimensions of 100mm×100mm×100mm. The 28-day compressive strength of the block samples is tested according to GB / T50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete", and is denoted as A. The etching solution was prepared by mixing 5% sodium chloride solution and 5% sodium sulfate solution at a volume ratio of 1:1. The etching solution was sprayed at a 30° angle to the surface of the block sample at a spray rate of 1.5 mL / (h·80cm²). 2 The spraying pressure was 120 kPa, the spraying ambient temperature was 35℃, and the spraying time was 120 h. After the block sample was taken out and air-dried, the compressive strength test was carried out. The obtained compressive strength value was recorded as A1. Finally, the salt erosion compressive strength loss rate of the block sample was calculated. The salt erosion compressive strength loss rate = (A-A1) / A. The higher the salt erosion compressive strength loss rate, the stronger the self-compacting shrinkage-compensating concrete's ability to resist salt erosion under strong winds in coastal areas.

[0065] After performing the above tests on test samples 1-18 and control samples 1-5, the test results are recorded in Table 2.

[0066] Table 2 Test results of test samples 1-18 and control samples 1-5 As can be seen from Example 1 and Comparative Example 1 and Table 2, adding specially prepared modified functional materials to self-compacting shrinkage-compensating concrete can significantly reduce salt erosion under strong winds in coastal areas and greatly eliminate the adverse effects of salt erosion. As a result, after the above tests, the loss rate of compressive strength due to salt erosion will be significantly reduced, indicating that self-compacting shrinkage-compensating concrete can maintain relatively excellent structural stability during application. Combining Comparative Examples 2-4 and Table 2, it can be seen that replacing the modified functional material with mica powder, while improving the salt erosion resistance compared to the case without the modified functional material, significantly reduces the effectiveness. Furthermore, while using a composite of cerium oxide and mica powder, or a composite of polyaniline and mica powder, can improve performance, the improvement is limited, and the combined effect of each is far less than the superior synergistic effect of the combination of mica, cerium oxide, and polyaniline. Therefore, it is evident that the modified functional material obtained through a specific combination of mica, cerium oxide, and polyaniline has a significant effect on improving the salt erosion resistance of self-compacting shrinkage-compensating concrete under strong winds in coastal areas.

[0067] As can be seen from Examples 1 and 10-16, and Table 2, the functional additives composed of elastic fibers and porous ceramic powder used in this application can further improve the salt erosion resistance of self-compacting shrinkage-compensating concrete under strong winds in coastal areas. The salt erosion compressive strength loss rate obtained from the above tests will be further reduced. Furthermore, as can be seen from Examples 17-18 and Table 2, while adding only elastic fibers or porous ceramic powder can improve the salt erosion resistance, the improvement effect is limited. Moreover, the sum of the improvement effects of adding either one individually is far less than the superior effect of their combination. Therefore, it is evident that elastic fibers and porous ceramic powder can bring a significant improvement effect (1+1>2) in self-compacting shrinkage-compensating concrete. Finally, as can be seen from Comparative Examples 1 and 5, and Table 2, if modified functional materials are lacking in the self-compacting shrinkage-compensating concrete, the corresponding effect brought by the functional additives is significantly reduced. This indicates that the functional additives can synergistically enhance the modified functional materials, thereby significantly improving the salt erosion resistance of self-compacting shrinkage-compensating concrete under strong winds in coastal areas.

[0068] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A self-compacting shrinkage-compensating concrete, characterized in that, Made from the following ingredients in parts by weight: 160-170 parts water; 395-415 parts cement; 635-655 parts of sand; 1000-1040 parts of crushed stone; 60-70 parts fly ash; 5.4-5.7 parts of admixture; 80-90 parts of mineral powder; 45-55 parts steel fiber; 40-48 parts of expanding agent; 20-25 parts of modified functional material; The modified functional material is prepared through the following steps: S1. After preheating the mica powder raw material, disperse it in water to form a suspension. Then add cerium salt solution and stir to mix. Next, add precipitant to react. After the reaction is completed, filter to obtain a solid product. Dry the solid product and calcine it to obtain pretreated mica powder. S2. The pretreated mica powder from step S1 is placed in a dilute phytic acid solution, ultrasonically mixed, and then aniline monomer and ammonium persulfate are added and stirred to react. After the reaction is completed, the solid product is obtained by filtration. The solid product is washed, dried and ground to obtain the modified functional material.

2. The self-compacting shrinkage-compensating concrete according to claim 1, characterized in that: In step S1 of the preparation of the modified functional material, the solid content of mica powder in the suspension is 10-15%, the concentration of cerium salt solution is 0.5-1 mol / L, and the mass mixing ratio of suspension and cerium salt solution is (3-5):

1.

3. The self-compacting shrinkage-compensating concrete according to claim 1, characterized in that: In step S2 of the preparation of the modified functional material, the weight ratio of pretreated mica powder to aniline monomer is (1-1.4):

1.

4. The self-compacting shrinkage-compensating concrete according to claim 1, characterized in that: The particle size of the modified functional material is 200-800 mesh.

5. The self-compacting shrinkage-compensating concrete according to claim 1, characterized in that: The raw materials also contain 10-15 parts by weight of functional additives, which are composed of elastic fibers and porous ceramic powder, and the weight ratio of elastic fibers to porous ceramic powder is (2.4-3.2):

1.

6. The self-compacting shrinkage-compensating concrete according to claim 5, characterized in that: The weight ratio of the elastic fiber to the porous ceramic powder is 2.8:

1.

7. The self-compacting shrinkage-compensating concrete according to claim 5, characterized in that: The elastic fiber has a length of 6-18 mm and a diameter of 10-20 μm; the porous ceramic powder has a particle size of 5-10 mm, a porosity of 30-40%, and a pore size of 45-55 μm.

8. The self-compacting shrinkage-compensating concrete according to claim 5, characterized in that: The weight ratio of the modified functional material to the functional additive is 22:

13.

9. The method for preparing self-compacting shrinkage-compensating concrete according to claim 1, characterized in that: Includes the following steps: (1) Prepare raw materials including water, cement, sand, crushed stone, fly ash, admixtures, mineral powder, steel fiber, expansion agent and modified functional material according to the proportion; (2) After mixing the sand and gravel in step (1), add cement, fly ash and mineral powder and mix. Then add water and admixtures and mix. Finally add steel fiber, expansion agent and modified functional material and mix to obtain self-compacting shrinkage-compensating concrete.

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