Self-repairing super high performance conductive concrete and preparation method thereof

Abstract

The present application relates to the technical field of concrete, and in particular to a self-repairing super high performance conductive concrete and a preparation method thereof, raw materials including, by weight, 1000 parts of cementitious material, the cementitious material being composed of 800 parts of 525 Portland cement and 200 parts of silica fume; 900 parts of filler, the filler being composed of 100 parts of 200-300 mesh quartz powder and 800 parts of 40-70 mesh quartz sand; the present application successfully integrates three functions of super high performance (compressive strength > 120 MPa), self-repairing (SMA driven) and conductivity (double fiber network) in one material; efficient self-repairing: using the shape memory effect of NiTi alloy fiber, small cracks can be actively closed, and the repair efficiency is good, and the performance can be repeatedly triggered.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, specifically to a self-healing ultra-high performance conductive concrete and its preparation method. Background Technology

[0002] Ultra-high performance concrete (UHPC) is widely used in critical civil infrastructure due to its superior mechanical properties and durability. However, UHPC inevitably develops microcracks during long-term service due to factors such as load and shrinkage. These cracks not only affect the durability of the structure but also disrupt the continuity of monitoring signals if internal sensing elements are present. In recent years, self-healing concrete and conductive concrete have become research hotspots. Self-healing technologies mainly include microbial mineralization repair, capsule repair, and shape memory alloy (SMA) repair. Among them, nickel-titanium (NiTi) shape memory alloy fibers can effectively close cracks by generating shrinkage force when they recover their original shape upon heating. Conductive concrete is usually achieved by incorporating conductive materials such as steel fibers and carbon fibers and is used in fields such as structural health monitoring and snow melting. However, existing technologies mostly focus on single functions, and research on integrating self-healing and conductivity and endowing materials with ultra-high performance is still relatively rare. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the purpose of this invention is to provide a self-healing ultra-high performance conductive concrete and its preparation method, so as to solve the problems mentioned in the background art.

[0004] The present invention solves the technical problem by adopting the following technical solution:

[0005] This invention provides a self-healing ultra-high performance conductive concrete, the raw materials of which include, by weight: 1000 parts of cementitious material, the cementitious material being composed of 800 parts of 525 silicate cement and 200 parts of silica fume;

[0006] 900 parts of filler, wherein the filler is composed of 100 parts of 200-300 mesh quartz powder and 800 parts of 40-70 mesh quartz sand;

[0007] The conductive reinforcing material consists of 9-18 parts carbon fiber; 32.25-97.5 parts self-healing material, which is nickel-titanium shape memory alloy fiber, with a volume content of 0.5%-1.1%, and the total volume content of the conductive reinforcing material and the self-healing material is 1.5%; 15 parts admixture, which is a water-reducing agent; and 180 parts water, with a water-to-binder ratio of 0.18.

[0008] Preferably, the volume fraction of the nickel-titanium shape memory alloy fiber is 0.5%-1.1%, the volume fraction of the carbon fiber is 0.4%-1%, and the total fiber fraction is 1.5%, which together form a continuous conductive network.

[0009] This invention also provides a method for preparing self-healing ultra-high performance conductive concrete, comprising the following steps:

[0010] Step 1: Add 525 silicate cement, silica fume and 50% by weight of carbon fiber into a mixer and mix at a low speed of 62.5 r / min for 3 minutes to obtain mixture A;

[0011] Step 2: Maintain a low stirring speed of 62.5 r / min for 3-6 minutes, during which time add a mixture of water and water-reducing agent, and then add the remaining 50% by weight of carbon fiber in small amounts several times to obtain mixture B;

[0012] Step 3: Continue stirring at a low speed of 62.5 r / min for 3-6 min, during which time the mixture of quartz powder and quartz sand is added, and then nickel-titanium shape memory alloy fibers are added in small amounts several times to obtain the final mixture C;

[0013] Pour the mixture C into a 40×40×160mm triple concrete mold. After each pour, vibrate it fully on the vibrating table for a total vibration time of no less than 1 minute. Smooth the surface and cover it with plastic wrap.

[0014] Step 4: After curing in a standard curing room with a temperature of 20±2℃ and a humidity of ≥95% for 24 hours, demold. After demolding, continue curing under the same standard curing conditions for 28 days.

[0015] Preferably, the carbon fiber has also undergone modification treatment, specifically the following modification method:

[0016] S1: Mix 3-5 parts bentonite, 2-5 parts sodium dodecylbenzenesulfonate solution (5% by mass) and 1-3 parts chitosan solution evenly to obtain bentonite liquid; mix 2-5 parts nanocellulose, 3-5 parts lanthanum nitrate solution and 1-3 parts aluminum borate whiskers evenly to obtain lanthanum liquid.

[0017] S2: Sonicate lanthanum liquid and bentonite liquid at a weight ratio of 3:(5-8). After sonication, bentonite-lanthanum body is obtained.

[0018] S3: 3-5 parts of carbon nanotubes, 2-4 parts of silicon dioxide and 1-2 parts of graphene are blended and sintered for 1 hour. After sintering, a sintered body is obtained. The sintered body and bentonite-lanthanum body are ball-milled at a weight ratio of (3-5):7 at a speed of 1000-1500 r / min for 2 hours. After ball milling, a modified liquid is obtained.

[0019] S4: Ball mill the carbon fiber and the modified liquid at a weight ratio of 6:(3-4) for improvement treatment. After ball milling, filter and dry.

[0020] Preferably, the chitosan solution has a mass fraction of 2-5%; the lanthanum nitrate solution has a mass fraction of 4-7%.

[0021] Preferably, the ultrasonic power for ultrasonic treatment is 350-400W, and the ultrasonic treatment lasts for 1 hour; the ball milling speed for ball milling improvement treatment is 1050-1150 r / min, and the ball milling lasts for 2 hours.

[0022] Preferably, the sintering temperature for blending is 210-220℃.

[0023] This invention also provides a performance verification method for self-healing ultra-high performance conductive concrete, characterized by comprising the following steps:

[0024] 1. Initial performance test: After curing for 28 days, the specimens were pre-embedded with brass mesh electrodes. The initial resistance value was measured using the two-electrode AC method. The effective area of ​​the electrodes and the initial resistivity of the spacing were combined to test the baseline mechanical properties.

[0025] 2. Introducing damage: A crack is pre-induced in the middle of the specimen through a three-point bending test. Loading and unloading are stopped when the crack width reaches a preset value.

[0026] 3. Thermal stimulation repair: Place the cracked specimen in an oven and heat it to above 100°C at a rate of 5°C / min. After holding it at that temperature for a period of time, cool it to room temperature with the oven.

[0027] 4. Repair effect evaluation: After cooling, the crack closure rate, resistivity recovery rate and mechanical property recovery rate are measured to quantitatively determine the repair effect; in step 1, the brass mesh electrode size is 30mm×60mm, the aperture is 4 mesh, the electrode spacing is 120mm, and the distance from both ends of the specimen is 20mm; in step 4, the oven heat preservation time is 60 minutes, and the austenitic phase transformation completion temperature is not lower than 100°.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention is a multifunctional integrated system: it successfully integrates three functions—ultra-high performance (compressive strength > 120 MPa), self-healing (SMA-driven), and conductivity (dual-fiber network)—into a single material; it features highly efficient self-healing: utilizing the shape memory effect of NiTi alloy fibers, it can actively close small cracks, achieving good repair efficiency, and its performance can be repeatedly triggered; the preparation process is reliable: through optimized feeding sequence and key carbon fiber dispersion processes, the problems of easy agglomeration and difficult dispersion of multiphase materials are effectively solved, ensuring the homogeneity and performance stability of the material; the "bentonite-lanthanum body" (the layered structure of bentonite + the ionic adsorption of lanthanum nitrate) in the modified liquid reduces the electrostatic repulsion on the carbon fiber surface, preventing agglomeration; the "carbon nanotube-silica-graphene sintered body" enhances the conductivity of carbon fibers (the high conductivity of graphene + the bridging effect of carbon nanotubes), while simultaneously strengthening the interfacial adhesion with the cement matrix (silica and CSH gel form chemical bonds), resulting in low agglomeration rate of modified carbon fibers, uniform distribution in the matrix, and optimized conductivity and mechanical reinforcement of the system, significantly improving the overall coordination of the product. Attached Figure Description

[0030] Figure 1 This is a flowchart of the concrete preparation process of the present invention;

[0031] Figure 2 Front view of the copper mesh arrangement for concrete test blocks;

[0032] Figure 3 Side view of the copper mesh arrangement for the concrete test block;

[0033] Figure 4 This is a schematic diagram of the copper mesh dimensions. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] A self-healing ultra-high performance conductive concrete, the raw materials by weight include: 1000 parts of cementitious material, the cementitious material being composed of 800 parts of 525 silicate cement and 200 parts of silica fume;

[0036] 900 parts of filler, wherein the filler is composed of 100 parts of 200-300 mesh quartz powder and 800 parts of 40-70 mesh quartz sand;

[0037] The conductive reinforcing material consists of 9-18 parts carbon fiber; 32.25-97.5 parts self-healing material, which is nickel-titanium shape memory alloy fiber, with a volume content of 0.5%-1.1%, and the total volume content of the conductive reinforcing material and the self-healing material is 1.5%; 15 parts admixture, which is a water-reducing agent; and 180 parts water, with a water-to-binder ratio of 0.18.

[0038] The volume fraction of nickel-titanium shape memory alloy fibers is 0.5%-1.1%, the volume fraction of carbon fibers is 0.4%-1%, and the total fiber content is 1.5%. The combination of the two enables the material to form a continuous conductive network.

[0039] A method for preparing self-healing ultra-high performance conductive concrete includes the following steps:

[0040] Step 1: Add 525 silicate cement, silica fume and 50% by weight of carbon fiber into a mixer and mix at a low speed of 62.5 r / min for 3 minutes to obtain mixture A;

[0041] Step 2: Maintain a low stirring speed of 62.5 r / min for 3-6 minutes, during which time add a mixture of water and water-reducing agent, and then add the remaining 50% by weight of carbon fiber in small amounts several times to obtain mixture B;

[0042] Step 3: Continue stirring at a low speed of 62.5 r / min for 3-6 min, during which time the mixture of quartz powder and quartz sand is added, and then nickel-titanium shape memory alloy fibers are added in small amounts several times to obtain the final mixture C;

[0043] Pour the mixture C into a 40×40×160mm triple concrete mold. After each pour, vibrate it fully on the vibrating table for a total vibration time of no less than 1 minute. Smooth the surface and cover it with plastic wrap.

[0044] Step 4: After curing in a standard curing room with a temperature of 20±2℃ and a humidity of ≥95% for 24 hours, demold. After demolding, continue curing under the same standard curing conditions for 28 days.

[0045] The carbon fiber also undergoes modification treatment, specifically the following modification methods:

[0046] S1: Mix 3-5 parts bentonite, 2-5 parts sodium dodecylbenzenesulfonate solution (5% by mass) and 1-3 parts chitosan solution evenly to obtain bentonite liquid; mix 2-5 parts nanocellulose, 3-5 parts lanthanum nitrate solution and 1-3 parts aluminum borate whiskers evenly to obtain lanthanum liquid.

[0047] S2: Sonicate lanthanum liquid and bentonite liquid at a weight ratio of 3:(5-8). After sonication, bentonite-lanthanum body is obtained.

[0048] S3: 3-5 parts of carbon nanotubes, 2-4 parts of silicon dioxide and 1-2 parts of graphene are blended and sintered for 1 hour. After sintering, a sintered body is obtained. The sintered body and bentonite-lanthanum body are ball-milled at a weight ratio of (3-5):7 at a speed of 1000-1500 r / min for 2 hours. After ball milling, a modified liquid is obtained.

[0049] S4: Ball mill the carbon fiber and the modified liquid at a weight ratio of 6:(3-4) for improvement treatment. After ball milling, filter and dry.

[0050] The chitosan solution has a mass fraction of 2-5%; the lanthanum nitrate solution has a mass fraction of 4-7%.

[0051] The ultrasonic treatment was performed with an ultrasonic power of 350-400W for 1 hour; the ball milling treatment was performed with a ball milling speed of 1050-1150 r / min for 2 hours.

[0052] The sintering temperature for blending is 210-220℃.

[0053] Five mix proportions were set up in this experiment. The mixing volume of each group was 1L. The basic components and dosages of each group were the same: 0.8 kg of 525 silicate cement, 0.2 kg of silica fume, 0.1 kg of 200-300 mesh quartz powder, 0.8 kg of 40-70 mesh quartz sand, and 0.18 kg of water. The water-cement ratio of each group was 0.18, and the dosage of water-reducing agent was 0.015 kg. The only difference was the amount of reinforcing fiber used: in experimental group 1, the amount of nickel-titanium alloy fiber was 0.0715 kg (volume fraction 1.1%) and the amount of carbon fiber was 0.0072 parts (volume fraction 0.4%); in experimental group 2, the amount of nickel-titanium alloy fiber was 0.0585 kg and the amount of carbon fiber was 0.0108 kg; in experimental group 3, the amount of nickel-titanium alloy fiber was 0.0455 kg and the amount of carbon fiber was 0.0144 kg; in experimental group 4, the amount of nickel-titanium alloy fiber was 0.0325 kg and the amount of carbon fiber was 0.018 kg; and in the control group, the amount of nickel-titanium alloy fiber was 0.0975 kg.

[0054] The preparation methods are all carried out according to the following steps, strictly following the process parameters:

[0055] 1. Add 525 silicate cement, silica fume, and 50% carbon fiber sequentially to a mortar mixer and mix at 62.5 rpm for 2 minutes until homogeneous, obtaining dry mixture A. 2. Add water and all the water-reducing agent to dry mixture A and mix at 62.5 rpm for 3 minutes, adding the remaining 50% carbon fiber in small amounts several times during the process to form a fluid slurry, obtaining mixture B. 3. Add the mixed quartz sand and quartz powder to mixture B and mix at 62.5 rpm for 5 minutes, adding nickel-titanium alloy fibers in small amounts several times during the process, mixing thoroughly to obtain the final concrete slurry.

[0056] Pouring and curing: The slurry is poured into a 40mm×40mm×160mm triple mold in two stages. After each pour, the mold is vibrated thoroughly on a vibrating table (total vibration time ≥1min). The surface is smoothed, covered with plastic wrap, and placed in a standard curing room (temperature 20±2°C, humidity ≥95%) for 24 hours before demolding. Curing continues for 28 days.

[0057] All the above carbon fibers have undergone modification treatment. The specific modification methods are as follows:

[0058] The carbon fiber also undergoes modification treatment, specifically the following modification methods:

[0059] S1: Mix 4 parts bentonite, 3.5 parts sodium dodecylbenzenesulfonate solution (5% by mass) and 2 parts chitosan solution evenly to obtain bentonite liquid; mix 3.5 parts nanocellulose, 4 parts lanthanum nitrate solution and 2 parts aluminum borate whiskers evenly to obtain lanthanum liquid;

[0060] S2: Sonicate lanthanum liquid and bentonite liquid at a weight ratio of 3:6.5. After sonication, bentonite-lanthanum body is obtained.

[0061] S3: 4 parts carbon nanotubes, 3 parts silicon dioxide and 1.5 parts graphene were blended and sintered for 1 hour. After sintering, a sintered body was obtained. The sintered body and bentonite-lanthanum body were ball-milled at a weight ratio of 4:7 at a speed of 1250 r / min for 2 hours. After ball milling, a modified liquid was obtained.

[0062] S4: Ball mill the carbon fiber and the modified liquid at a weight ratio of 6:3.5. After ball milling, filter and dry the mixture.

[0063] The chitosan solution has a mass fraction of 3.5%; the lanthanum nitrate solution has a mass fraction of 5.5%.

[0064] The ultrasonic treatment was performed with an ultrasonic power of 370W for 1 hour; the ball milling treatment was performed with a ball milling speed of 1100 r / min for 2 hours.

[0065] The sintering temperature for blending is 215℃.

[0066] Experimental test example: verification of self-healing performance and conductivity.

[0067] To verify the self-healing and electrical conductivity properties of the concrete described in this invention, the following experiments were conducted on the specimens obtained in the examples:

[0068] Specimen preparation and initial testing: During specimen casting, two 30mm × 60mm brass meshes with 4mm apertures were pre-embedded as electrodes. The meshes were spaced 120mm apart and 20mm from both ends of the specimen (e.g., ...). Figure 2 (As shown). After 28 days of curing, the resistance value R0 of the specimen under non-destructive condition was measured using the two-electrode AC method, and its initial resistivity ρ0 was calculated according to formula (1).

[0069] ,

[0070] in, ρ Resistivity (Ω·m) R To measure the resistance (Ω). S The effective area of ​​the electrode (m²) 2 ), L The distance between electrodes is (m).

[0071] Damage (cracking) introduction: The specimen was subjected to a three-point bending test using a fatigue testing machine with a span of 100 mm and a displacement loading rate of 0.1 mm / min. The crack width was predicted by the downward displacement and geometric relationship. When the crack width reached the preset value of 0.5 mm, the loading was stopped and the load was unloaded.

[0072] Thermal self-healing: The specimen with cracks was placed in a forced-air oven and subjected to heating stimulation. The heating regime was as follows: the temperature was increased to 100°C at a rate of 5°C / min, held for 60 minutes, and then cooled to room temperature in the oven.

[0073] Repair effectiveness assessment:

[0074] (1) Morphological repair assessment: Measure the change in crack width before and after heating and calculate the crack closure rate.

[0075] (2) Mechanical property recovery assessment: The self-healing specimen was subjected to a three-point bending test again to test its ultimate load and assess the recovery rate of mechanical properties.

[0076] The experimental results of experimental groups 1-4 and the control group are shown in the table below:

[0077]

[0078]

[0079]

[0080]

[0081] Experimental group 1 exhibited excellent electrical conductivity. After thermal excitation, the crack width was effectively reduced due to the shape memory effect of the NiTi alloy fibers, achieving functional self-repair. Comparison of different experimental groups leads to the conclusion that the higher the NiTi alloy fiber content, the better the self-repair effect.

[0082] Table 1. Analysis of compressive strength data:

[0083] The average compressive strength of all experimental and control groups exceeded 120 MPa, which meets the core definition of "ultra-high performance" and verifies that the mechanical properties of the formulation meet the standards.

[0084] The highest average value (124.13 MPa) was found in experimental group 1 (1.1% nickel-titanium volume fraction and 0.4% carbon fiber volume fraction), while the lowest average value (116.92 MPa) was found in experimental group 4 (0.5% nickel-titanium volume fraction and 1.0% carbon fiber volume fraction). This indicates that the amount of nickel-titanium alloy fiber has a positive contribution to compressive strength.

[0085] The control group containing only nickel-titanium fibers (mean 122.02 MPa) performed similarly to most of the experimental groups, demonstrating that the combination of carbon fiber and nickel-titanium fiber does not weaken the compressive strength and achieves lossless integration of "conductive + self-healing" functions.

[0086] Table 2 Analysis of flexural strength and repair effect data:

[0087] Initial flexural strength values: control group (21.76 MPa) > experimental group 1 (20.20 MPa) > experimental group 2 (19.60 MPa) > experimental group 3 (17.76 MPa) > experimental group 4 (16.48 MPa), which is positively correlated with the amount of nickel-titanium fiber. Nickel-titanium fiber can enhance the flexural strength of the material.

[0088] Repair effect: The recovery rate of flexural strength showed a significant decreasing trend. The control group (0.71) > experimental group 1 (0.67) > experimental group 2 (0.54) = experimental group 3 (0.54) > experimental group 4 (0.37), which directly proves that the amount of nickel-titanium fiber is the key factor for the self-repair effect. The higher the amount, the more fully the mechanical properties are restored after repair.

[0089] Table 3: Crack Repair Data Analysis

[0090] The trend of crack closure rate was consistent with that of flexural recovery rate: control group (0.481) > experimental group 1 (0.416) > experimental group 2 (0.303) > experimental group 3 (0.245) > experimental group 4 (0.137), which verified that the shape memory effect of NiTi alloy fiber is the core driving force for crack closure.

[0091] Even though the initial crack width of experimental group 2 (0.66 mm) was greater than that of experimental group 1 (0.48 mm), the closure rate was still significantly lower than that of experimental group 1 due to the lower nickel-titanium doping content. This indicates that the doping content has a higher priority on the repair effect than the initial crack width.

[0092] Table 4 Resistivity Data Analysis:

[0093] Conductivity patterns: The resistivity at each age was lowest in experimental group 1 (180.10 Ω·m at 28 days) and highest in experimental group 4 (261.20 Ω·m at 28 days), indicating that the ratio of carbon fiber to nickel-titanium directly affects the continuity of the conductive network. The conductive network formed by the combination of experimental group 1 (1.1% nickel-titanium + 0.4% carbon fiber) is the most complete.

[0094] Age effect: The resistivity of all groups increased with the curing age (significantly increasing from 1 day to 28 days), which is a normal manifestation of the densification of the internal structure during the hydration and hardening process of concrete. However, experimental group 1 always maintained the lowest resistivity and had the best conductivity stability.

[0095] The control group, which contained only nickel-titanium fibers, had a higher resistivity (244.23 Ω·m) after 28 days than the experimental groups 1-3, demonstrating that carbon fiber is a key material for improving conductivity, and that the conductivity of the dual-fiber network is better than that of the single fiber.

[0096] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0097] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A self-healing ultra-high performance conductive concrete, characterized in that, The raw materials, by weight, include: 1000 parts of cementitious material, which is composed of 800 parts of 525 silicate cement and 200 parts of silica fume; 900 parts of filler, wherein the filler is composed of 100 parts of 200-300 mesh quartz powder and 800 parts of 40-70 mesh quartz sand; The product contains conductive reinforcing materials and self-healing materials. The volume fraction of the conductive reinforcing material (carbon fiber) is 0.4%-1%, and the self-healing material (nickel-titanium shape memory alloy fiber) has a volume fraction of 0.5%-1.1%. The total volume fraction of the conductive reinforcing material and the self-healing material is 1.5%. The product also contains 15 parts of an additive, which is a water-reducing agent, and 180 parts of water, resulting in a water-to-binder ratio of 0.

18. The preparation method of the self-healing ultra-high performance conductive concrete includes the following steps: Step 1: Add 525 silicate cement, silica fume, and 50% by weight of carbon fiber to a mixer to obtain mixture A; Step 2: Maintain a low stirring speed of 62.5 r / min for 3-6 minutes, during which time add a mixture of water and water-reducing agent, and then add the remaining 50% by weight of carbon fiber in small amounts several times to obtain mixture B; Step 3: Continue stirring at a low speed of 62.5 r / min for 3-6 min, during which time the mixture of quartz powder and quartz sand is added, and then nickel-titanium shape memory alloy fibers are added in small amounts several times to obtain the final mixture C; Pour the mixture C into a 40×40×160mm triple concrete mold. After each pour, vibrate it fully on the vibrating table for a total vibration time of no less than 1 minute. Smooth the surface and cover it with plastic wrap. Step 4: After curing in a standard curing room with a temperature of 20±2℃ and a humidity of ≥95% for 24 hours, demold and continue curing under the same standard curing conditions for 28 days. The carbon fiber also undergoes modification treatment, specifically the following modification methods: S1: Mix 3-5 parts bentonite, 2-5 parts sodium dodecylbenzenesulfonate solution (5% by mass) and 1-3 parts chitosan solution evenly to obtain bentonite liquid; mix 2-5 parts nanocellulose, 3-5 parts lanthanum nitrate solution and 1-3 parts aluminum borate whiskers evenly to obtain lanthanum liquid. S2: Sonicate lanthanum liquid and bentonite liquid at a weight ratio of 3:(5-8). After sonication, bentonite-lanthanum body is obtained. S3: 3-5 parts of carbon nanotubes, 2-4 parts of silicon dioxide and 1-2 parts of graphene are blended and sintered for 1 hour. After sintering, a sintered body is obtained. The sintered body and bentonite-lanthanum body are ball-milled at a weight ratio of (3-5):7 at a speed of 1000-1500 r / min for 2 hours. After ball milling, a modified liquid is obtained. S4: Ball mill the carbon fiber and the modified liquid at a weight ratio of 6:(3-4). After ball milling, filter and dry the mixture. The sintering temperature for blending is 210-220℃.

2. The self-healing ultra-high performance conductive concrete according to claim 1, characterized in that, Mixture A was prepared by stirring at a low speed of 62.5 r / min for 3 min.

3. The self-healing ultra-high performance conductive concrete according to claim 1, characterized in that, The chitosan solution has a mass fraction of 2-5%; the lanthanum nitrate solution has a mass fraction of 4-7%.

4. The self-healing ultra-high performance conductive concrete according to claim 1, characterized in that, The ultrasonic treatment was performed with an ultrasonic power of 350-400W for 1 hour; the ball milling treatment was performed with a ball milling speed of 1050-1150 r / min for 2 hours.

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