Self-repairing anti-abrasion concrete based on heat-shrinkable fiber net and electromagnetic induction self-repairing fiber and preparation method thereof

Abstract

The present invention discloses a self-repairing, abrasion-resistant concrete based on a heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers. The concrete comprises an abrasion-resistant concrete matrix and a cross-linked, modified heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers distributed therein. The cross-linked, modified heat-shrinkable fiber mesh is a fiber mesh woven and cross-linked with polyester and aramid fibers. The electromagnetic induction self-repairing fibers comprise a core material and a wall material, wherein the core material comprises methyl methacrylate and butyl acrylate, and the wall material comprises polylactic acid and nano-Fe3O4. The present invention combines the cross-linked, modified heat-shrinkable fiber mesh with electromagnetic induction self-repairing fiber technology to effectively enhance the stability, load-bearing capacity, and abrasion resistance of concrete, achieve controlled self-repair of concrete cracks, and significantly improve the durability and service life of concrete. This provides a new approach for the preparation of high-performance abrasion-resistant concrete.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and in particular relates to a self-repairing and abrasion-resistant concrete based on a heat-shrinkable fiber net and electromagnetic induction self-repairing fibers, and a preparation method thereof. Background Art

[0002] Abrasion-resistant concrete usually uses high-performance aggregates, special cements and additives, which can significantly improve the physical and mechanical properties of concrete. This type of concrete has high compressive strength and flexural strength, as well as good impact resistance and wear resistance. Its application scenarios include airport runways, port terminals, industrial floors, etc. However, abrasion-resistant concrete is prone to quality defects such as delamination and floating during the construction process; furthermore, it is sensitive to environmental conditions, and changes in temperature and humidity can affect its performance. Cracks are common in concrete structures (possibly caused by shrinkage, temperature changes, or load deformation, etc.). These cracks will reduce the strength and durability of the structure, affecting safety and service life. Traditional repair methods such as drilling and grouting and surface coating repairs have limitations such as unstable results, complex operations, and time-consuming.

[0003] Fiber-reinforced concrete (FRC) is a composite material that improves its toughness and crack resistance by adding various types of fibers to concrete. However, a single fiber mainly provides local reinforcement by evenly distributing the fibers in the concrete. This only improves microcracks and local areas and cannot cope with large structures with high loads and high stresses. Concrete composites composed of high-performance fiber woven mesh and concrete matrix have excellent mechanical properties, good durability and light weight. They can be used for building structure reinforcement and new building structures, but the following problems and shortcomings still exist: the fiber mesh alone is difficult to deal with the expansion of concrete cracks, and its ability to repair and toughen larger cracks is limited; if the surface treatment technology is not perfect, it will also lead to insufficient bonding with the matrix material, resulting in debonding and other phenomena. Heat-shrinkable fiber technology also has certain applications in concrete, but it mainly works at specific temperatures. In actual engineering environments with small temperature changes, the heat shrinkage performance is difficult to fully demonstrate; in addition, short-cut heat-shrinkable fibers have no significant effect on improving the durability of concrete and cannot effectively solve the corrosion and aging problems that concrete faces in the long run.

[0004] Microencapsulation technology incorporates microcapsules containing a repair agent into cementitious materials. When cracks appear, the capsules rupture, releasing the repair agent to fill the cracks and prevent them from expanding, thereby improving the durability and service life of the material. While self-repairing can be achieved to a certain degree, it often faces challenges such as weak wall materials that are easily damaged, the high selectivity and difficulty in controlling the reactivity of the core material, and the uncontrollable or limited controllable release of the repair agent, which hinder the self-repair effect. Furthermore, the use of self-repairing microcapsules alone has limited impact on the overall mechanical properties of concrete and cannot meet the requirements of projects requiring high strength and abrasion resistance. Summary of the Invention

[0005] The main purpose of the present invention is to address the problems and shortcomings of the existing technology and provide a self-repairing and abrasion-resistant concrete based on heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber. The combination of cross-linked modified heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber technology can effectively improve the stability, bearing capacity and abrasion resistance of concrete, and realize the self-repair of concrete cracks, which can significantly improve the durability and service life of concrete, etc., and has a wide applicability.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A self-repairing, abrasion-resistant concrete based on a heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers comprises an abrasion-resistant concrete matrix and cross-linked, modified heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers distributed therein; the cross-linked, modified heat-shrinkable fiber mesh is a fiber mesh in which polyester fiber and aramid are sequentially woven and cross-linked; the electromagnetic induction self-repairing fibers comprise a core material and a wall material, the core material comprising methyl methacrylate (MMA) and butyl acrylate (BA), and the wall material comprising polylactic acid (PLA) and nano-Fe3O4.

[0008] In the above scheme, the raw materials of the self-repairing and abrasion-resistant concrete and their weight proportions include: 1008-1140 parts of the raw materials used for the abrasion-resistant concrete matrix, 12-44 parts of electromagnetic induction self-repairing fibers, and 50-70 parts of cross-linked modified heat-shrinkable fiber mesh.

[0009] Furthermore, the raw materials of the anti-abrasion concrete matrix and their weight proportions include: 400 parts of silicate cement, 78-110 parts of silica fume, 350-400 parts of fine sand, 70-90 parts of steel fiber, 15-20 parts of water reducer, and 95-120 parts of water.

[0010] Furthermore, the electromagnetic induction self-repairing fibers account for 3 to 11% of the mass of the cement.

[0011] In the above solution, the heat shrinkable fiber mesh is woven into a mesh using a process such as a plain weave method.

[0012] In the above scheme, the cross-linking modification step includes: soaking the blended web of polyester fiber and aramid fiber in a divinylbenzene cross-linking agent solution, cross-linking reaction, removing the fiber web, and drying to obtain a cross-linked modified fiber web.

[0013] Furthermore, in the divinylbenzene cross-linking agent solution, the concentration of divinylbenzene is 10-15 wt %; and the solvent used is cyclohexane, toluene or xylene.

[0014] In the above scheme, the cross-linking reaction time is 2 to 3 hours.

[0015] In the above scheme, the drying temperature is 90-100° C. and the drying time is 2-4 hours.

[0016] In the above scheme, the speed of stirring to obtain the cross-linking solution is 300-500 r / min and the time is 15-30 min.

[0017] In the above scheme, the pore size of the obtained heat-shrinkable fiber mesh is 500-1000 μm, and the fiber diameter is 3-20 μm.

[0018] Furthermore, the blending ratio (mass ratio) of the polyester fiber and the aramid fiber is 1:2 to 2:1.

[0019] In the above solution, the average diameter of the electromagnetic induction self-repairing fiber is 0.2-2 μm, the average thickness of the capsule wall is 50-300 nm; and the length of the electromagnetic induction self-repairing fiber is 250-4000 μm.

[0020] Furthermore, the aspect ratio of the electromagnetic induction self-repairing fiber is 500-2000.

[0021] Furthermore, the added amount of the electromagnetic induction self-repairing fiber accounts for 3 to 11% of the mass of the cement.

[0022] In the above solution, the method for preparing the electromagnetic induction self-repairing fiber comprises the following steps:

[0023] 1) Preparation of core material: Methyl methacrylate, butyl acrylate, a crosslinker, and an initiator are weighed according to the ratio; the weighed methyl methacrylate and butyl acrylate are stirred uniformly (stirring at room temperature for 10 to 15 minutes), and then divinylbenzene and azobisisobutyronitrile are added and stirred for 30 to 40 minutes to obtain a composite core material;

[0024] 2) Preparation of spinning solution: Prepare a polylactic acid solution (the solvent can be chloroform, etc.), add the obtained composite core material to it, stir evenly, add tributyl citrate and stir evenly (stir for 10 to 15 minutes), then add ferrosoferric oxide nanoparticles and ultrasonically disperse (30 to 40 minutes) to obtain a spinning solution containing the core material, wall material and magnetic material;

[0025] 3) Electrospinning: The prepared spinning solution is electrospun to form fibrous microcapsules.

[0026] In the above scheme, methyl methacrylate (MMA) is used as the main repair agent, accounting for 70-80% of the total mass of the core material; butyl acrylate (BA) is used as an auxiliary repair agent to adjust the core material performance, accounting for 20-30% of the total mass of the core material.

[0027] In the above solution, the crosslinking agent can be divinylbenzene (DVB), etc., accounting for 5-10% of the total mass of the core material; the initiator can be azobisisobutyronitrile (AIBN), etc., accounting for 1-3% of the total mass of the core material.

[0028] In the above scheme, the concentration of polylactic acid in the polylactic acid solution is 0.15-0.25 g / mL; and an organic solvent such as chloroform is used.

[0029] In the above scheme, in the obtained spinning solution, the volume percentage of the solvent is 70-80%; the mass percentage of tributyl citrate is 5-10%; and the mass percentage of ferrosoferric oxide nanoparticles is 3-5%.

[0030] In the above scheme, the process parameters used in the electrospinning step include: the distance between the needle and the receiving device is 15 to 25 cm, the set voltage is 15 to 25 kV, the spinning speed is 0.5 to 1.5 mL / h, the spinning process lasts 2 to 3 hours, and the spinning fiber length is set to 250 to 4000 μm to obtain electromagnetic induction self-healing fiber.

[0031] Furthermore, the silicate cement is one of P·I 52.5 grade and P·II 52.5 grade.

[0032] Furthermore, the content of SiO2 in the silica fume is ≥92%, and the particle size of the silica fume is 0.1-0.3 μm.

[0033] Furthermore, the fine sand is one of natural sand and quartz sand, and the particle size of the fine sand is 0.075-0.6 mm.

[0034] Furthermore, the steel fiber is a copper-plated steel fiber; the length of the steel fiber is 12 to 13 mm, and the diameter is 0.18 to 0.23 mm.

[0035] Furthermore, the water reducer is a polycarboxylic acid water reducer with a water reduction rate of ≥25%.

[0036] The above-mentioned method for preparing the self-repairing and abrasion-resistant concrete based on the heat-shrinkable fiber net and the fibrous electromagnetic induction microcapsules comprises the following steps:

[0037] 1) The cross-linked modified heat-shrinkable fiber mesh is placed in the middle of the mold according to the structural requirements of the impact-resistant concrete;

[0038] 2) preparing a slurry for the anti-abrasion concrete matrix according to the proportion, then adding the electromagnetic induction self-repairing fiber to the obtained slurry and stirring evenly;

[0039] 3) pouring the obtained mixture into a mold provided with a heat-shrinkable fiber mesh, forming, and curing to obtain the self-repairing and impact-resistant concrete.

[0040] In the above solution, the abrasion-resistant concrete is a cylindrical or block structure.

[0041] Furthermore, when preparing cylindrical impact-resistant concrete, the heat-shrinkable fiber mesh is hollow cylindrical and is arranged in the middle position coaxial with the cylindrical impact-resistant concrete; when preparing block impact-resistant concrete, the heat-shrinkable fiber mesh is a planar mesh structure and is arranged parallel to the surface of the impact-resistant concrete in the middle position of the cylindrical impact-resistant concrete along the thickness direction.

[0042] Furthermore, when preparing cylindrical impact-resistant concrete, in the pouring process of step 3), the mixture is first poured into the hollow cylindrical heat-shrinkable fiber mesh. After hardening and shaping, the remaining mixture is continued to be poured until the mold is filled.

[0043] In the above solution, the abrasion-resistant concrete adopts a standard curing process.

[0044] The self-repairing anti-abrasion concrete prepared according to the above scheme has a compressive strength of 90.3-127.8 MPa and an anti-abrasion strength of 97.2 h / (kg / m 2 )~117.5h / (kg / m 2 ).

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention uses polyester fiber and aramid to prepare a heat-shrinkable fiber mesh. The cross-linked modified heat-shrinkable fiber mesh is beneficial to enhancing the bonding force between the fiber and concrete, and can effectively prevent the fiber from being pulled out during the impact and abrasion process, thereby improving the integrity of the concrete. Secondly, the heat release of cement hydration causes the heat-shrinkable fiber mesh to shrink in response, generating pre-compressive stress on the surrounding hardened gel slurry, thereby inhibiting the further expansion of microcracks. By dispersing these stresses, the heat-shrinkable fiber mesh can exhibit better ductility and impact resistance when subjected to impact or vibration, thereby preventing brittle failure. Moreover, after the heat shrinkage treatment, the fiber structure is made tighter, forming a three-dimensional reinforced network in the concrete, which can absorb and disperse energy, prevent the generation and expansion of cracks, and improve crack resistance and toughness. The introduced fiber mesh can inhibit the generation of microcracks by shrinkage and enhance the impact and abrasion resistance. The above characteristics work together to significantly improve the durability of concrete, better resist environmental factors such as water erosion, chemical erosion, and alternating dry and wet conditions, prevent the entry of corrosive media, and delay the deterioration process. The heat-shrinkable fiber mesh can ensure the enhanced protective effect during long-term use and extend the service life of impact-resistant concrete.

[0047] (2) The electromagnetic induction self-repairing fiber prepared by the present invention can trigger the release of the repair agent by applying a magnetic field when the concrete is damaged by impact and abrasion. At the same time, the heat-shrinkable fiber mesh is stimulated to shrink in response to heat, which synergistically promotes the realization of the self-repairing function, significantly prolongs the service life of the concrete and improves its durability; and can simultaneously enhance the integrity and toughness of the concrete, improve its impact and abrasion resistance, and the electromagnetic controlled release is controllable; the obtained fibrous structure has a large specific surface area, the repair agent is released faster, and the repair efficiency is improved; it can better combine with the cement matrix to form a uniform reinforced network, and improve the mechanical properties and impact and abrasion resistance; biodegradable polylactic acid is used as the wall material, which is environmentally friendly and has good long-term stability, avoids the problems of aging and degradation of traditional materials, and has good biocompatibility; the obtained electromagnetic induction self-repairing fiber has stable quality and performance, which is conducive to ensuring the stable release of the repair agent.

[0048] (3) The present invention combines heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber, which can significantly improve the durability and service life of concrete, effectively enhance the stability and bearing capacity of concrete and realize the self-repair of concrete cracks. It has the advantages of high environmental adaptability and rapid repair, and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic structural diagram of the abrasion-resistant concrete according to Example 1 of the present invention;

[0050] Figure 2 Comparison of the self-repairing effects of cracks in impact-resistant concrete that incorporates both heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber: (a) before repair; (b) after repair. DETAILED DESCRIPTION

[0051] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0052] In the following embodiments, the heat shrinkable fiber mesh used is woven from polyester fiber and aramid fiber using a plain weave method. The modification preparation method includes the following steps:

[0053] 1. Weigh 10 g of divinylbenzene and slowly add it to 90 g of cyclohexane. Stir with a stirrer (speed 400 r / min, time 25 min) to obtain a crosslinking solution.

[0054] 2. Immerse a blended web of polyester fiber and aramid fiber prepared by a plain weave method in a cross-linking solution for 2.5 hours. After the soaking is completed, take out the fiber web and place it in a well-ventilated place to drain excess solution; then place the fiber web in an oven (90°C, 3 hours) to obtain the heat-shrinkable fiber web.

[0055] To further verify the heat shrinkage performance of the fiber web of the present invention, the obtained heat-shrinkable fiber web was placed in a high-temperature furnace, and the temperature was raised to 100-180°C at a rate of 5-10°C / min and kept warm for 30 minutes to allow the fiber web to shrink. The pore size change results of the obtained fiber web are shown in Table 3.

[0056] The mechanical and physical property test results of the polyester fiber and aramid fiber used are shown in Tables 1 and 2, respectively; the tensile strength, Young's modulus and elongation are measured by quasi-static testing; the performance test structure of the obtained heat-shrinkable fiber mesh is shown in Table 3.

[0057] Table 1 Mechanical and physical properties of polyester fibers

[0058]

[0059] Table 2 Mechanical and physical properties of aramid

[0060]

[0061] Table 3 Changes in the aperture of heat shrinkable fiber mesh

[0062]

[0063] The preparation method of the electromagnetic induction self-repairing fiber comprises the following steps:

[0064] 1. Accurately weigh 80 g of methyl methacrylate, 30 g of butyl acrylate, 6.32 g of divinylbenzene, and 10 g of azobisisobutyronitrile according to the mass ratio; place the weighed methyl methacrylate and butyl acrylate into a clean and dry three-necked flask, add a magnetic stirrer, turn on the magnetic stirrer, and stir at room temperature for 15 minutes to fully mix; slowly add divinylbenzene and azobisisobutyronitrile to the above mixed solution, continue stirring for 40 minutes to ensure that all reagents are evenly mixed, and obtain a composite core material for later use;

[0065] 2. Weigh 10.5 g of polylactic acid and put it into another clean and dry three-necked flask. Measure 70 mL of chloroform and slowly add it to the three-necked flask. Stir at 40 ° C for 1 hour to completely dissolve the polylactic acid in chloroform to form a polylactic acid solution with a concentration of 0.15 g / mL; add the composite core material (126.32 g) obtained in step 1 to the obtained polylactic acid solution, and continue stirring for 30 minutes to uniformly disperse it; according to the total mass of the spinning solution, weigh 5% of the total mass of the spinning solution of tributyl citrate (10.75 g), pour it into the three-necked flask, and stir for 15 minutes; weigh 3% of the total mass of the spinning solution of ferroferric oxide nanoparticles (6.77 g) and pour it into the three-necked flask; turn on the ultrasonic disperser and ultrasonically disperse for 35 minutes to uniformly disperse the ferroferric oxide nanoparticles in the spinning solution to obtain a spinning solution containing core material @ wall material and magnetic material and good spinnability;

[0066] 3. Use a syringe to draw up the prepared spinning solution, ensuring that there are no bubbles inside the syringe and needle; install the syringe on the electrospinning device, adjust the distance between the needle and the receiving device to 20 cm, set the voltage of the electrospinning device to 15 kV, and the spinning speed to 1.5 mL / h; turn on the electrospinning device, and under the action of the electrostatic field, the spinning solution is ejected from the needle to form spun fibers on the receiving device. The spinning process lasts for 3 hours;

[0067] 4. The collected spun fibers were placed in a fume hood at room temperature for 48 h to allow the chloroform and other organic solvents to fully evaporate, and then dried (in a vacuum drying oven at 50 ° C for 24 h) to obtain dry electromagnetic induction self-repairing fibers.

[0068] Table 4 Performance test results of electromagnetic induction self-repairing fibers

[0069]

[0070] In the following examples, the cement used was P·I 52.5 grade, the silica fume had a particle size of 0.25 μm, the fine sand was natural sand with a particle size of 0.075 to 0.6 mm, the steel fibers used were copper-coated steel fibers with a length of 12 to 13 mm and a diameter of 0.18 to 0.23 mm, and the water reducer was a polycarboxylate water reducer with a water reduction rate of 25%.

[0071] Example 1

[0072] A self-repairing, abrasion-resistant concrete (the specimen is cylindrical) based on a heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers, wherein the components and their weight percentages include: 1062 parts of self-repairing, abrasion-resistant concrete raw material, 12 parts of electromagnetic induction self-repairing fibers, and 60 parts of a cross-linked, modified heat-shrinkable fiber mesh; wherein the self-repairing, abrasion-resistant concrete raw material includes: 400 parts of silicate cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber, 17 parts of a water reducer, and 100 parts of water; the cross-linked, modified heat-shrinkable fiber mesh is a hollow cylindrical structure obtained by blending polyester fiber and aramid using a plain weave method (polyester fiber: aramid = 1:2); the preparation method of the self-repairing, abrasion-resistant concrete comprises the following steps:

[0073] 1) 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber and 12 parts of electromagnetic induction self-repairing fiber (accounting for 3% of the mass of cement) were mixed evenly, and then 100 parts of water and 17 parts of water reducer were added and mixed evenly, and stirred for 2 minutes to obtain abrasion-resistant concrete slurry;

[0074] 2) 60 parts of a cross-linked modified heat-shrinkable fiber mesh (a blend of polyester fiber and aramid in a ratio of 1:2) were placed in the center of a cylindrical cavity mold. First, part of the impact-resistant concrete slurry was filled into the cylindrical fiber mesh (with baffles on both sides). After the concrete inside was set, it was poured to fill the entire mold. After forming, it was placed in a curing room for standard curing for 28 days (temperature 25°C, humidity 95%) to obtain self-repairing impact-resistant concrete based on the heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber.

[0075] Comparative Example 1

[0076] A traditional abrasion-resistant concrete, the preparation method of which comprises the following steps:

[0077] 1) 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand and 80 parts of steel fiber were mixed evenly, and then 100 parts of water and 17 parts of water reducer were added and mixed evenly, and stirred for 2 minutes to obtain an anti-abrasion concrete slurry;

[0078] 2) pouring, shaping, and curing the obtained abrasion-resistant concrete slurry to obtain the abrasion-resistant concrete.

[0079] Comparative Example 2

[0080] A reinforced abrasion-resistant concrete based on a cross-linked modified heat-shrinkable fiber mesh, the preparation method of which comprises the following steps: 1) mixing a concrete slurry: 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, and 80 parts of steel fiber are uniformly mixed, and then 100 parts of water and 17 parts of a water reducer are added and mixed uniformly to obtain an abrasion-resistant concrete slurry;

[0081] 2) 60 parts of a cross-linked modified heat-shrinkable fiber mesh (polyester fiber and aramid blended in a ratio of 1:2; prepared as in Example 1) were placed in the center of a cylindrical cavity mold. First, part of the impact-resistant concrete slurry was filled into the cylindrical fiber mesh (with baffles on both sides). After the concrete inside was set, the concrete was poured to fill the entire mold. After forming, the mold was placed in a curing room for standard curing for 28 days (temperature 25°C, humidity 95%) to obtain reinforced impact-resistant concrete based on the cross-linked modified heat-shrinkable fiber mesh.

[0082] Comparative Example 3

[0083] A method for preparing abrasion-resistant concrete based on electromagnetic induction self-repairing fibers comprises the following steps:

[0084] 1) 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber, and 12 parts of electromagnetic induction self-repairing fiber (prepared by the same method as in Example 1) were mixed evenly, and then 100 parts of water and 17 parts of a water reducer were added, mixed evenly, and stirred for 2 minutes to obtain an impact-resistant concrete slurry;

[0085] 2) pouring and curing the concrete slurry to obtain electromagnetic induction self-repairing fiber impact and wear resistant concrete.

[0086] Comparative Example 4

[0087] A method for preparing abrasion-resistant concrete based on hydrophilic modified composite chopped fibers and electromagnetic induction self-repairing fibers comprises the following steps:

[0088] 1) Mixing the concrete slurry: 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber, and hydrophilically modified short fibers (including 20 parts of hydrophilically modified polyester and 40 parts of hydrophilically modified aramid short fibers) (length 3-12 mm), and 12 parts of electromagnetic induction self-repairing fibers (prepared by the same method as in Example 1) were mixed uniformly, and then 100 parts of water and 17 parts of a water reducer were added and mixed uniformly to obtain an abrasion-resistant concrete slurry;

[0089] 2) Filling a portion of the abrasion-resistant concrete slurry into a mold, curing after molding, and obtaining abrasion-resistant concrete based on the hydrophilic modified chopped fibers and the electromagnetic induction self-repairing fibers.

[0090] Comparative Example 5

[0091] A method for preparing abrasion-resistant concrete based on a heat-shrinkable fiber mesh and electromagnetic induction self-repairing fibers comprises the following steps:

[0092] 1) 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber and 12 parts of electromagnetic induction self-repairing fiber (accounting for 3% of the mass of cement) were mixed evenly, and then 100 parts of water and 17 parts of water reducer were added and mixed evenly, and stirred for 2 minutes to obtain an impact-resistant concrete slurry;

[0093] 2) 60 parts of the heat-shrinkable fiber mesh (polyester fiber and aramid blended in a ratio of 1:2, the preparation method is the same as in Example 1) are placed in the center of the cylindrical cavity mold. First, part of the impact-resistant concrete slurry is filled into the cylindrical fiber mesh (baffles are set on both sides). After the concrete inside is shaped, continue to pour and fill the entire mold. After forming, it is placed in a curing room for standard curing for 28 days (temperature 25°C, humidity 95%) to obtain self-repairing impact-resistant concrete based on the heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber; wherein, the preparation method of the heat-shrinkable fiber mesh used is roughly the same as that in Example 1, the only difference is that no cross-linking modification is performed before blending and weaving.

[0094] The concrete obtained in Example 1 and Comparative Examples 1 to 5 were tested for mechanical properties and durability, and the results are shown in Table 4.

[0095] Table 5 Performance test results of the concrete obtained in Example 1 and Comparative Examples 1 to 5 after curing for 28 days

[0096]

[0097] A self-healing experiment was conducted on the self-repairing and abrasion-resistant concrete based on the heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber obtained in Example 1. The specific steps include:

[0098] Using the splitting test method, micro cracks are generated on the surface of the specimen. The specimen is immediately removed and the initial crack width is measured.

[0099] For the above concrete specimens, the temperature was raised to 200℃ and the magnetic field intensity was 0.3T to further observe the crack repair situation. The specific repair results are shown in Figure 2 It can be seen that the method of the present invention can achieve self-repair of cracks with a width of 0.29 mm.

[0100] In order to verify the precise controlled release effect of the electromagnetic induction self-repairing fiber described in the present invention, by setting different magnetic field conditions such as magnetic field strength and action time, the release amount of the repair agent was measured by HPLC and other methods. With the increase of magnetic field strength and action time, the release amount of repair material (core material) in the microcapsule increased, the release amount was less at low magnetic field strength, and the cracks were effectively repaired at high magnetic field strength; different magnetic field frequencies resulted in different release rates and patterns. Low-frequency slow release is suitable for long-term repair, and high-frequency fast release is used for emergency treatment.

[0101] Examples 2 to 5

[0102] The preparation method of the self-repairing and abrasion-resistant concrete described in Examples 2 to 5 is roughly the same as that in Example 1, except that the blending ratio of the fiber mesh and the electromagnetic induction self-repairing fiber ratio (percentage of cement mass) are different. The performance test results of the fiber mesh, electromagnetic induction self-repairing fiber and the obtained concrete after 28 days of curing are shown in Table 6.

[0103] Table 6 Performance test results of the fiber mesh-electromagnetic induction self-repairing fiber system and the resulting concrete used in Examples 2 to 4

[0104]

[0105]

[0106] Example 5

[0107] A self-repairing, abrasion-resistant concrete based on a heat-shrinkable fiber mesh and an electromagnetic induction self-repairing fiber (the specimen is in block form), wherein the components and their weight percentages include: 1062 parts of a self-repairing, abrasion-resistant concrete matrix raw material, 12 parts of an electromagnetic induction self-repairing fiber, and 60 parts of a cross-linked, modified heat-shrinkable fiber mesh; wherein the self-repairing, abrasion-resistant concrete raw material includes: 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, 80 parts of steel fiber, 17 parts of a water reducer, and 100 parts of water; the heat-shrinkable fiber mesh is woven by plain weaving polyester fiber and aramid according to different blending ratios (see Table 7 for details); the preparation method of the self-repairing, abrasion-resistant concrete comprises the following steps:

[0108] 1) 400 parts of Portland cement, 95 parts of silica fume, 370 parts of fine sand, and 80 parts of steel fiber were mixed with different amounts of electromagnetic induction self-repairing fibers (see Table 7 for details), and then 100 parts of water and 17 parts of water reducer were added and mixed evenly. The mixture was stirred for 2 minutes to obtain abrasion-resistant concrete slurry.

[0109] 2) 60 parts of the heat-shrinkable fiber mesh were placed in the middle of the mold and the anti-impact concrete slurry was poured to fill the entire mold. After molding, it was placed in a curing room for 28 days (temperature 25°C, humidity 95%) to obtain self-repairing anti-impact concrete based on the heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber.

[0110] Table 7 Performance test results of different fiber mesh-electromagnetic induction self-repairing fiber systems and the resulting concrete in Example 6

[0111]

[0112] The above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A self-repairing and abrasion-resistant concrete based on heat-shrinkable fiber net and electromagnetic induction self-repairing fiber, characterized in that: It includes an impact-resistant concrete matrix and a cross-linked modified heat-shrinkable fiber mesh and electromagnetic induction self-repairing fiber distributed inside it; the heat-shrinkable fiber mesh is a fiber mesh that is woven and cross-linked with polyester fiber and aramid in sequence; the electromagnetic induction self-repairing fiber includes a core material and a wall material, the core material includes methyl methacrylate and butyl acrylate, and the wall material includes polylactic acid and nano-Fe3O4.

2. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The raw materials and their weight proportions include: 1008-1140 parts of impact-resistant concrete matrix raw materials, 12-44 parts of electromagnetic induction self-repairing fibers, and 50-70 parts of cross-linked modified heat-shrinkable fiber mesh.

3. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The raw materials and their weight proportions in the impact-resistant concrete matrix include: 400 parts of Portland cement, 78-110 parts of silica fume, 350-400 parts of fine sand, 70-90 parts of steel fiber, 15-20 parts of water reducer, and 95-120 parts of water.

4. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The cross-linking modification step is to use divinylbenzene to perform cross-linking modification on the blended web of polyester fiber and aramid fiber.

5. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The electromagnetic induction self-repairing fiber has an average diameter of 0.2-2 μm, an average capsule wall thickness of 50-300 nm, and a length of 250-4000 μm.

6. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The electromagnetic induction self-repairing fiber is firstly cross-linked with methyl methacrylate and butyl acrylate to obtain a composite core material, which is then mixed with a polylactic acid solution and ferrosoferric oxide nanoparticles to prepare a spinning solution, and then electrostatic spinning is performed to obtain the fiber.

7. The self-repairing and abrasion-resistant concrete according to claim 1, characterized in that: The mass ratio of methyl methacrylate, butyl acrylate, polylactic acid and ferrosoferric oxide nanoparticles introduced is 1:(0.25~1):(0.1~0.3):(0.025~0.15).

8. The self-repairing and abrasion-resistant concrete according to claim 3, characterized in that: The silicate cement is one of P·I 52.5 grade and P·II 52.5 grade; the SiO2 content in the silica fume is ≥92%, and the particle size is 0.1-0.3 μm; the fine sand is one of natural sand and quartz sand, and the particle size of the fine sand is 0.075-0.6 mm; the steel fiber is copper-plated steel fiber, with a length of 12-13 mm and a diameter of 0.18-0.23 mm.

9. The self-repairing and abrasion-resistant concrete according to claim 3, characterized in that: The water reducer is a polycarboxylic acid water reducer with a water reduction rate of ≥25%.

10. The method for preparing the self-repairing anti-abrasion concrete based on the heat-shrinkable fiber net and the electromagnetic induction self-repairing fiber according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) The cross-linked modified heat shrinkable fiber mesh is placed in the middle of the mold according to the structural requirements of the impact-resistant concrete; 2) Prepare a slurry for the anti-abrasion concrete matrix according to the proportion, then add the electromagnetic induction self-repairing fiber into the obtained slurry and stir evenly; 3) pouring the obtained mixture into a mold provided with a cross-linked modified heat-shrinkable fiber mesh, forming, and curing to obtain the self-repairing and abrasion-resistant concrete.

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