WO2020098271A1 - 一种腐蚀驱动智能纤维及其制备方法和应用 - Google Patents

一种腐蚀驱动智能纤维及其制备方法和应用 Download PDF

Info

Publication number
WO2020098271A1
WO2020098271A1 PCT/CN2019/091912 CN2019091912W WO2020098271A1 WO 2020098271 A1 WO2020098271 A1 WO 2020098271A1 CN 2019091912 W CN2019091912 W CN 2019091912W WO 2020098271 A1 WO2020098271 A1 WO 2020098271A1
Authority
WO
WIPO (PCT)
Prior art keywords
corrosion
fiber
resistant coating
core fiber
core
Prior art date
Application number
PCT/CN2019/091912
Other languages
English (en)
French (fr)
Inventor
孙宇雁
王子国
程淑珍
吴俊�
Original Assignee
青岛理工大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 青岛理工大学 filed Critical 青岛理工大学
Priority to AU2019284139A priority Critical patent/AU2019284139B2/en
Priority to JP2021525575A priority patent/JP7029866B2/ja
Publication of WO2020098271A1 publication Critical patent/WO2020098271A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/71—Ceramic products containing macroscopic reinforcing agents
    • C04B35/74—Ceramic products containing macroscopic reinforcing agents containing shaped metallic materials
    • C04B35/76—Fibres, filaments, whiskers, platelets, or the like
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/08—Members specially adapted to be used in prestressed constructions

Definitions

  • the invention relates to a corrosion-driven intelligent fiber and a preparation method and application thereof; it belongs to the technical field of civil engineering.
  • Concrete materials are currently the most widely used and widely used man-made construction materials in the world.
  • due to their shortcomings such as brittleness, low tensile strength, and low limit elongation, they are prone to cracks during use and under the influence of the surrounding environment.
  • corrosive media such as air, water, and chloride ions penetrate the cracks inside the structure to corrode the steel bars, reducing the service life of the engineering structure and endangering the safety of the structure.
  • hydraulic dams, railway engineering, highway bridges, port and marine engineering, tunnel and mine engineering, pipeline engineering, nuclear power engineering, etc. put forward higher requirements on the performance of concrete, so fiber reinforced concrete should be transported Born to prevent and suppress the formation and development of cracks by investing in fibers, improve the crack resistance, toughness, and permeability resistance of concrete.
  • this method is divided into three methods: mineral crystallization precipitation method, cement-based infiltration crystallization method, and microorganism crystallization method.
  • One of the crack repair factors of the crystallization precipitation method is the crack repair of cracks and unhydrated cement particles and other mineral additives (such as C 3 S, C 2 S, etc.) generated by the hydration products to repair cracks.
  • This repair function The effect is minimal, but the dominant factor is the formation of CaCO3 crystalline precipitates by dissolved water CO 2 and slightly soluble Ca (OH) 2 to seal the healing cracks.
  • the problems of mineral crystallization precipitation method are: the healing function of this method is greatly affected by the age, crack size, number, distribution and specific environment of the concrete, the healing period is longer, and the healing function of the later age concrete is basically lost, greater than Cracks with a width of 0.15mm are basically difficult to heal.
  • the cement-based permeable crystalline material is composed of ordinary portland cement, quartz sand, and chemical compounds with active functional groups.
  • the active functional groups are in a dormant state.
  • the concrete cracks, water infiltrates, and the Ca 2+ concentration at the gap decreases to a certain extent, the active functional groups undergo polycondensation reaction to generate new crystals, and the cracks are automatically filled and repaired quickly.
  • the problems of the cement-based infiltration crystallization method are: the crack self-repair width is limited, and the effect of repairing cracks with a width of more than 0.4mm is not good.
  • the microbial remediation technology is to put specific harmless bacteria (aerobic basophilic bacillus) into the concrete material.
  • the interior of the non-destructive concrete is a high-alkali anoxic environment, and the bacteria are in a dormant state.
  • the infiltration of oxygen and water activates bacterial spores, and during its metabolism, CO 2 is generated and reacts with Ca 2+ in the concrete material to form calcium carbonate crystals, which are sealed to repair the cracks.
  • This method is a kind of intelligent bionic self-healing concrete, which is divided into microcapsule method and hollow fiber (hollow fiber or hollow fiber) method according to the type of repair agent carrier.
  • microcapsules / hollow fibers loaded with repair adhesives are implanted in concrete.
  • the microcapsules / hollow fibers are broken where the cracks pass
  • the repair agent flows out of the crack and penetrates into the crack, contacts the catalyst dispersed in the concrete, solidifies and hardens, quickly seals the crack, and realizes self-repair.
  • the problems of the repair agent filling method are: This method is a very complex repair system.
  • the repair agent covers organic synthesis, polymer chemistry, fine chemical industry, microcapsule / hollow fiber technology, implantation technology, etc. It is still in the experimental research stage.
  • Existing smart materials that can sense the active deformation of external stimuli and provide driving force-shape memory materials mainly include shape memory alloys and shape memory polymers, but the memory polymer has little recovery from deformation and is not suitable for self-healing drive.
  • the shape memory alloy can be driven by self-healing due to its high strength and high recovery force.
  • the SMA method stimulates the shrinkage deformation of the shape memory alloy wire pre-buried in the concrete by electric heating, and provides a driving force for the closing of the crack. This method actively adjusts the crack width by applying pre-pressure to the structure, which is beyond the reach of the above methods.
  • the problems of the shape memory alloy drive closing method are: because the shape memory alloy is a thermally deformable material, it needs to be heated and excited to shrink the alloy wire, and the drive crack closing requires a series of supporting equipment. The entire drive and control system is complex and cumbersome. Because the resistance of the SMA material itself is not large, the energized heating requires a large current, and the requirements for power supply and wire are very high. The heating temperature has a great influence on the shape recovery of SMA and the mechanical properties of concrete. Due to the heat conduction of concrete, SMA temperature control is technically difficult. Too low temperature SMA is difficult to drive. Excessive heating and uneven heating will cause concrete to reappear Temperature crack. In addition, to drive the crack to close and achieve self-repair, a large amount of SMA is required, and SMA is expensive, 700 times the price of ordinary steel, which is enough to stifle the application of SMA method in concrete.
  • the repair of crack defects in concrete is an urgent task.
  • the application of cement-based permeable crystalline materials is a more successful intelligent repair material, but the repair The effect is limited by the width of the crack.
  • Other methods basically stay in the experimental exploration stage because the repair mechanism is too complicated, or the repair effect is not good. Therefore, in order to achieve the ideal self-healing effect, the crack width control of the concrete is very important.
  • the present invention proposes a corrosion-driven intelligent fiber, its preparation method and application.
  • the invention provides a corrosion-driven intelligent fiber; the corrosion-driven intelligent fiber is composed of core fibers and / or core fibers with a corrosion-resistant coating and a corrosion-resistant coating; the core fibers and / or cores with a corrosion-resistant coating
  • the fiber is in a tensile stress state along the fiber length; the corrosive coating is in a compressive stress state along the fiber length; and the core fiber and / or core fiber with a corrosion-resistant coating and the corrosive coating are in a tensile direction along the fiber length Pressure equilibrium state; the easily corrodible coating coats the core fiber and / or the core fiber with a corrosion-resistant coating.
  • the corrosion rate of the corrosive coating is greater than that of the core fiber; and / or, under the same corrosive environment, the corrosion rate of the corrosive coating is greater than that of the core with the corrosion-resistant coating The rate of fiber corrosion.
  • the present invention is a corrosion-driven smart fiber
  • the corrosion-driven smart fiber includes a core fiber and a corrosion-resistant coating, and a part or all positions outside the core fiber are covered with a corrosion-resistant coating;
  • the corrosion-driven smart fiber includes a corrosion-resistant coating, a core fiber, and a corrosion-resistant coating; a portion or all positions outside the core fiber are covered with a corrosion-resistant coating; when a portion or all positions outside the core fiber When coated with a corrosion-resistant coating, the resulting material is defined as A; a part of the surface of A or a portion of the entire surface is coated with a corrosion-resistant coating,
  • the corrosion-driven intelligent fiber includes a core fiber, a corrosion-resistant coating, and a corrosion-resistant coating; the core fiber is coated with a corrosion-resistant coating; a portion of the corrosion-resistant coating is coated with a corrosion-resistant coating ;
  • the corrosion-driven smart fiber includes a core fiber and a corrosion-resistant coating, and a part or all positions outside the core fiber are covered with a corrosion-resistant coating; the part outside the core fiber includes the end of the core fiber; when the core When the end of the fiber is covered with a corrosion-resistant coating, the end of the corrosion-resistant coating is also covered with a corrosion-resistant coating;
  • the corrosion-driven smart fiber includes a corrosion-resistant coating, a core fiber, and a corrosion-resistant coating; a portion or all positions outside the core fiber are covered with a corrosion-resistant coating; when a portion or all positions outside the core fiber
  • the anti-corrosion coating is coated on it, the resulting material is defined as A; the part of the surface of A is covered with a corrosion-resistant coating, or when the end of A is covered with a corrosion-resistant coating, the end is The corrosion-resistant coating is also covered with anti-corrosion coating;
  • the core fiber and / or the core fiber with a corrosion-resistant coating are in a tensile stress state along the fiber length direction; the easily corrodible coating is in a compressive stress state along the fiber length direction;
  • the corrosion rate of the corrosive coating is greater than that of the core fiber; and / or, under the same corrosive environment, the corrosion rate of the corrosive coating is greater than the corrosion rate of the core fiber with the corrosion-resistant coating .
  • the invention provides a corrosion-driven smart fiber; the core fiber is selected from at least one of inorganic fibers and polymer fibers; the equivalent diameter of the core fiber is less than or equal to 20 mm, preferably less than or equal to 5 mm.
  • the equivalent diameter is the diameter of the fiber cross-sectional area converted into a circular cross-section.
  • the invention provides a corrosion-driven smart fiber;
  • the inorganic fiber is selected from at least one of C fiber, glass fiber, mineral fiber, basalt fiber, ceramic fiber, and metal fiber;
  • the metal fiber is selected from steel fiber and M-plated steel At least one of fibers, stainless steel fibers, copper alloy fibers, titanium alloy fibers, and nickel alloy fibers;
  • the M is selected from at least one of copper, nickel, chromium, tin, cadmium, and silver elements.
  • the polymer fiber is selected from at least one of polypropylene fiber, polyacrylonitrile fiber, polyvinyl alcohol fiber, polyethylene fiber, aramid fiber, polyester fiber, and nylon fiber.
  • the invention provides a corrosion-driven smart fiber; the material of the corrosion-resistant coating is selected from at least one of copper, nickel, chromium, cadmium, silver, and gold elements.
  • the material of the anticorrosive coating is selected from at least one of copper, nickel, chromium, cadmium, silver, and gold elements.
  • a corrosion-resistant coating is prepared by plating or coating.
  • the invention relates to a corrosion-driven intelligent fiber; the core fiber or the core fiber coated with a corrosion-resistant coating has a standard electrode potential greater than that of a corrosion-resistant coating, or its activity is less than that of a corrosion-resistant coating.
  • the invention relates to a corrosion-driven smart fiber;
  • the corrosion-driven smart fiber includes a corrosion-resistant coating, a core fiber or a core fiber with a corrosion-resistant coating, and the side surfaces of the core fiber or the core fiber with a corrosion-resistant coating are easily coated Corrosion coating
  • the corrosion-driven smart fiber includes a corrosion-resistant coating, a core fiber, or a core fiber with a corrosion-resistant coating, and the sides of the core fiber or the corrosion-resistant coating fiber except for the anchoring end are covered with a corrosion-resistant coating.
  • the invention relates to a corrosion-driven smart fiber; the corrosion-resistant coating is iron metal or iron alloy, the core fiber is steel fiber, and the corrosion-resistant coating is copper metal or copper alloy.
  • the invention provides a method for preparing a corrosion-driven smart fiber; applying a tensile force to a core fiber or a core fiber with a corrosion-resistant coating; then preparing a corrosion-resistant coating on a set area on the surface; removing the tensile force to obtain a sample; the applied The tensile force is 10% to 90% of the load capacity of the core fiber or core fiber with a corrosion-resistant coating.
  • the core fiber with a corrosion-resistant coating described in the preparation method includes at least two cases. In the first case, the corrosion-resistant coating is evenly coated on the surface of the core fiber. In the second case, the core fiber is coated on a predetermined area on the surface of the core fiber. Corrosion-resistant coating. In industrial applications, if it is necessary to provide a corrosion-resistant coating on the end; then apply another layer of corrosion-resistant coating on the end of the resulting sample.
  • the corrosion-resistant coating can be directly prepared at the set position on the sample surface.
  • the invention provides a method for preparing a corrosion-driven smart fiber; in the entire corrosion-driven smart fiber, in order to maximize the prestress applied by the smart fiber to the outside world, its optimized acquisition method is:
  • the size of the prestressed storage of the smart fiber is closely related to the volume fraction V f of the core fiber, and the axial force F stored by the core fiber is:
  • V f satisfies the condition of formula 16, so that F can take the maximum value, that is, Fmax.
  • the application of the corrosion-driven smart fiber of the present invention includes its use in concrete or fiber-reinforced resin composite materials.
  • the corrosion-driven smart fiber of the present invention when the corrosion-driven smart fiber is used in concrete, the corrosion-driving condition is the use environment of the concrete.
  • the use environment of concrete H 2 O / O 2, Cl -, SO 4 -2 as the main medium of corrosive, acidic or corrosive substances as the main corrosive media.
  • These corrosive media are one of the prerequisites for driving corrosion-driven smart fibers to exhibit intelligence.
  • the invention provides an application of corrosion-driven intelligent fibers: the corrosion-driven intelligent fibers are anchored in concrete.
  • the anchoring method may be at least one of adhesive anchoring and / or mechanical anchoring.
  • the application of the corrosion-driven intelligent fiber of the present invention when the corrosion-driven intelligent fiber is used in concrete, its dosage is 0.01-20v%.
  • the material of the corrosion-resistant coating is preferably a corrosion-prone iron metal material (such as elemental iron, low-carbon iron, iron alloy, etc.), doped with harmful substances (such as carbon, nitrogen, Phosphorus and silicon and other harmful trace elements) easily form iron-based metal materials that are corroded electrochemically or alloys that easily form intergranular corrosion.
  • a corrosion-prone iron metal material such as elemental iron, low-carbon iron, iron alloy, etc.
  • harmful substances such as carbon, nitrogen, Phosphorus and silicon and other harmful trace elements
  • the corrosion-resistant coating of the present invention may be composed of a single layer material, a multi-layer material or a functionally graded material.
  • the cross-sectional shape of the corrosion-driven smart fiber of the present invention may be circular, polygonal, or irregular cross-section (including groove, cross, cross shape, trilobal, plum blossom, or star shape), the axial line shape may be wavy, and the surface may be It is indented or ribbed.
  • the corrosion-driven smart fiber of the present invention may be composed of a single fiber or a twisted wire formed by twisting and twisting multiple fibers.
  • the core fiber in the corrosion-driven smart fiber of the present invention may be composed of a single fiber or a twisted wire formed by twisting and twisting multiple fibers.
  • the corrosion-driven intelligent fiber of the present invention forms an anchoring end at the target body, which has a fully plated end hook type, a bare end straight hook type, a bare end hook type, an end pier head anchor type, and an end flat head anchor type.
  • the shape of the corrosion-driven intelligent fiber of the present invention is straight, prism-shaped, corrugated, hook-shaped, big-headed, double big-headed, double-pointed or bundled.
  • all or part of the coating may be a multilayer or a composite coating.
  • An anchoring end is provided at the end, or multiple locations are set on the longer smart fiber to establish anchoring points, as shown in FIG. 7.
  • the invention relates to the application of corrosion-driven intelligent fibers; when the corrosion-driven intelligent fibers are used in concrete, the construction and maintenance methods are exactly the same as the existing concrete.
  • the present invention proposes for the first time to add core fibers with corrosion coating to concrete; through the anchoring effect of concrete, the ability of anti-corrosion and crack prevention in the early stage is equivalent to that of existing concrete; when the core fibers with corrosion coating When it starts to corrode, it exhibits the function of gradually repairing the cracks that have been generated until the cracks are completely closed; this greatly extends the service life of the concrete.
  • adding core fiber with corrosion coating to the concrete can also reduce the probability of premature cracking of the concrete, improve the mechanical properties, durability and safety of the concrete structure, and have a great effect on improving the crack resistance of the low modulus polymer fiber concrete component. help.
  • the invention proposes a corrosion-driven smart fiber and self-healing concrete, the principle of which is to prepare a smart fiber (the core fiber is not easy to be corroded and corroded) (The coating is easily corroded), the shape of the intelligent fiber is stimulated by the corrosion of the corrosive medium in the environment, and the prestress is applied to the concrete to provide power for the crack closure of the concrete.
  • the prestress applied to the concrete to provide power for the crack closure of the concrete.
  • the application of prestress can improve the mechanical properties, durability and safety of concrete structures, provide a new design idea for shape memory materials, and provide a new concept for the self-repair and self-healing of concrete and other composite materials.
  • the invention proposes a fiber with corrosion-driven shape memory function, which drives intelligent fibers to undergo shrinkage and deformation through corrosive media entering concrete in the environment, applies prestress to concrete, and mechanically closes concrete cracks, providing a new brand for intelligent self-healing of concrete
  • the method provides a brand-new idea for applying prestress in arbitrary positions and directions in concrete materials.
  • Corrosion-driven smart fibers are composed of core fibers and corrosion-resistant coatings, where the core fiber materials are composed of corrosion-resistant materials or materials coated with corrosion-resistant coatings, and corrosion-resistant coating materials are composed of Consists of materials corroded by corrosive media in the environment.
  • the preparation method of smart fiber is shown in Figure 1, and the preparation steps are carried out in order from a to d.
  • a indicates that the core fiber is in a stress-free state
  • b indicates that the core fiber is pre-tensioned in the elastic range, and the tensile stress is ⁇ o
  • c indicates that the core fiber tensile stress ⁇ o remains unchanged, when Surface deposition, spraying, or electroplating are used to uniformly apply a corrosion-resistant coating, and the corrosion-resistant coating is in a stress-free state
  • d indicates that after the coating is applied, the tensile force is removed, assuming that the core fiber is easily corroded The coating is well combined.
  • the corrosion-resistant coating retracts in the axial direction under the elastic recovery force of the core fiber, and the resulting compressive stress is Eventually the two establish a tension-pressure balance, the corrosion-resistant coating stores the pre-compression stress and corresponding pre-compression strain, and the core fiber stores the pre-tension stress and corresponding pre-tension strain.
  • FIG. 2 The mechanism of smart fiber shape recovery is shown in Figure 2.
  • Figure a shows that the smart fiber is not corroded, the core fiber and the corrosive coating are in the original equilibrium state;
  • Figure b shows that in a corrosive medium environment, the corrosive coating first comes into contact with the corrosive medium, and the corrosion is unbearable. Corrosion products of load, and the core fiber has strong corrosion resistance, and there will be no loss of cross-section and strength.
  • the effective thickness of the cross-section becomes smaller after the corrosion.
  • the compressive stress and compressive deformation of the layer continue to increase, and the core fiber shrinks accordingly, gradually approaching the initial length; as shown in Figure c, when the corrosive coating is corroded, the core fiber returns to the original length, completing a single pass Memory effect, the core fiber at this time is in a stress-free state.
  • the core fiber has pre-tension strain stored in the axial direction, and the pre-strain strain is stored in the corrosive coating, and the two are in a state of tension and compression balance;
  • the corrosion-resistant coating material needs to be composed of a material that is easily corroded by corrosive media in the environment, and the core fiber is composed of a corrosion-resistant material or a material coated with a corrosion-resistant coating.
  • the concrete structure is cracked by factors such as temperature, humidity, and external forces.
  • the smart fibers at the crack defects are corroded by corrosive media in the environment.
  • the shape recovery is excited, and the pre-pressure is applied to the concrete to provide power for the crack closure.
  • the self-healing principle of corrosion-driven intelligent fibers is shown in Figure 3, and the self-healing process is carried out in order from a to c.
  • Figure a shows that the concrete cracked, but the smart fiber has not been corroded and is in a stable state.
  • Figure b shows the chemical or electrochemical reaction between the corrosive coating at the crack and the corrosive medium, and the smart fiber is stimulated to retract and pass through the bonding area (the bonding and anchoring interface of the corrodible coating that has not been corroded and the concrete)
  • the higher the corrosion degree of the corrosive coating the greater the closing force and the smaller the crack width.
  • the corrosion-resistant coating corrodes to a certain degree, when the closing force acting on the crack surface is large enough, the crack closes, the passage of the corrosive medium into the internal is cut off, the corrosion stops, and the self-healing protection function is achieved. At this time, the retractive force and pre-pressure of the core fiber stop increasing.
  • the smart fiber is a unidirectional composite material with a sufficiently long slenderness ratio, in order to simplify the calculation of the internal force of the smart fiber, the following assumptions can be made:
  • the stress of the core fiber and the corrosive coating is in a linear elastic state
  • the structural unit is positive in tension and negative in compression.
  • ⁇ o is the initial tensile stress value of the core fiber
  • E 1 E f V f + E c V c is the elastic modulus (composite elastic modulus) of the smart fiber.
  • E c and E f are the elastic modulus of the corrosion-resistant coating and the core fiber, respectively (when the core fiber is provided with a corrosion-resistant coating, its elastic modulus is calculated according to the calculation formula of the composite elastic modulus);
  • the size of the smart fiber prestress storage is closely related to the volume fraction V f of the core fiber.
  • the axial force F stored by the core fiber is
  • V f satisfies the condition of formula 16, so that F can take the maximum value, namely Fmax.
  • Equation 16 In engineering applications, if the calculated value of Equation 16 is not in the range of 5v% to 95v%, it is better to adjust the volume fraction V f of the core fiber to 5v% to 95v%.
  • the smart fiber with the permanent anchoring end is mixed into the concrete, and the prestress applied by the concrete when the shape of the smart fiber recovers is predicted.
  • the permanent anchoring end is in the following two situations:
  • the corrosion-driven smart fiber is composed of a core fiber and a corrosion-resistant coating; a portion of the surface of the core fiber is not covered with a corrosion-resistant coating, and the core fiber is located in concrete.
  • the part of the corrosion coating is the permanent anchoring end, and the length of any permanent anchoring end is defined as l ′;
  • the corrosion-driven smart fiber is composed of core fiber, corrosion-resistant coating, and corrosion-resistant coating; the permanent anchoring end is coated with a corrosion-resistant coating on the surface of the core fiber and coated with corrosion-resistant Corrosion of the coating part; meanwhile, the core fiber is located in the concrete, and the length of any one of the permanent anchoring ends is defined as l;
  • the tensile stress of the core fiber is:
  • the composite elastic modulus of core fiber and concrete is:
  • the elastic modulus of concrete as: E m;
  • ⁇ is the bonding force of the interface between the smart fiber and the concrete (when the composition and structure of the concrete and smart fiber are determined, it is a known quantity)
  • l ′ is the anchor length of the permanent anchor end in the concrete (the length of one end)
  • D is the cross-sectional diameter of the anchoring end.
  • Figure 1 is a schematic diagram of the preparation process of smart fibers
  • Figure 2 is a diagram of the shape recovery mechanism of corrosion-driven smart fibers
  • Figure 3 is a schematic diagram of self-healing intelligent fiber driven by corrosion
  • Figure 4 is a diagram of the stress balance process of the corrosion-resistant coating under the elastic recovery force of the core fiber
  • FIG. 5 is a graph of the influence of the amount of smart fibers and the change of initial tensile stress on the prestress of concrete in the calculation process of Example 1.
  • FIG. 6 is a schematic diagram of several structures of smart fibers designed by the present invention.
  • FIG. 7 is a layout diagram of anchor points.
  • FIG. 8 is a schematic view of the structure of the concrete test piece of Example 1.
  • the core fiber of the smart fiber uses copper-plated steel fiber (diameter 0.2mm, copper plating is negligible), and the corrosion-resistant coating uses metal iron.
  • the cross-sectional area of the core fiber and the corrosion-resistant coating is 1: At 1 o'clock, the prestressed storage of smart fibers reaches maximum.
  • the content of smart fiber in concrete is 4v%.
  • the basic parameters of smart fiber and concrete are shown in Table 1.
  • the prestress applied to the concrete by core fiber retraction is:
  • the maximum pre-stress of the 4% smart fiber to the concrete release is 9.3MPa. If the volume fraction of the smart fiber and the initial tensile force of the core fiber continue to be increased, the pre-load applied to the concrete The stress will continue to increase.
  • the size of the prestress can be controlled by the size and volume fraction of the initial tensile stress of the smart fiber.
  • the application of the prestress can close the crack of the concrete, reduce the stress concentration, increase the rigidity, improve the corrosion resistance, and improve the toughness. Is advantageous.
  • the existence of prestressing has great help to the crack resistance of concrete components, especially low modulus polymer fiber concrete components.
  • the characteristics of the concrete test piece are as follows.
  • the size of the concrete test piece is 200mm ⁇ 20mm ⁇ 40mm (length ⁇ width ⁇ height), which is divided into a piece of absorbent tissue perpendicular to the length of the test piece and a thickness of 0.3mm
  • Two parts, A and B simulate the penetrating cracks of the test piece with absorbent tissue to form a corrosive medium channel.
  • the two parts A and B of the test piece are connected by 20 shape memory steel fibers with a length of 180 mm and a diameter of 0.28 mm.
  • the core fiber of each smart fiber uses copper-plated steel fibers with a diameter of 0.2 mm and a strength of 3000 MPa.
  • the initial tensile stress is 2000Mpa
  • the corrosion-resistant coating is electroplated iron metal
  • the thickness is 0.04mm.
  • 20 fibers are arranged side by side and vertically passed through the absorbent cotton paper.
  • the middle section of each fiber is wrapped with a 50 mm long and 0.2 mm thick absorbent cotton paper as a water absorption channel to increase the corrosion rate of the easy-to-corrosive layer of smart fibers and accelerate shape intelligence Fiber recovery speed.
  • the characteristics and preparation method of the concrete test piece of Comparative Example 1 are basically the same as those of Example 1. The difference is that the initial tensile stress of the core fiber of the 20 steel fibers connecting the two parts of the test pieces A and B is 0 MPa, that is, the iron coating with a thickness of 0.04 mm is electroplated without tension.
  • the concrete test piece of Comparative Example 1 was immersed in a 6% sodium chloride solution. After 48 hours, a small amount of brown rust appeared at the crack, and the width of the crack was found to be unchanged by measurement. Absorb the rust on the absorbent paper between the two parts, and then continue to soak in the sodium chloride solution for 48 hours, it is found that the brown paper rust oozes out of the cracked tissue, and the width of the crack is not narrowed by measurement; continue to soak, after 15 days It was found that the brown rust at the crack still oozed out, and the width of the crack was basically unchanged. The experimental results found that these 20 steel fibers did not have shape memory function, which caused the penetration crack formed by the absorbent tissue to not be closed, indicating that the steel fiber prepared by electroplating iron coating under no tension has no memory function and cannot heal the concrete. crack.
  • the characteristics and preparation method of the concrete test piece of Comparative Example 2 are basically the same as those of Example 1. The difference is that the initial tensile stress of the core fiber of the 20 steel fibers connecting the two parts of the test pieces A and B is 0 MPa, that is, a 0.04 mm thick copper coating is electroplated without tension.
  • the concrete test piece of Comparative Example 2 was immersed in 6% sodium chloride solution. After 48 hours, no abnormal changes were found in the cracks, and the width of the cracks remained unchanged; after continued immersion in sodium chloride solution for 48 hours, no Brown rust oozed out, and the width of the crack remained the same; after soaking, the crack remained unchanged after 15 days, and the width of the crack remained the same.
  • the characteristics and preparation method of the concrete test piece of Comparative Example 3 are basically the same as those of Example 1. The difference is that the initial tensile stress of the core fiber of the 20 steel fibers connecting the two parts of the test pieces A and B is 2000Mpa, that is, a 0.04mm thick copper coating is electroplated without tension.
  • the concrete test piece of Comparative Example 3 was immersed in 6% sodium chloride solution. After 48 hours, no abnormal changes were found in the cracks, and the width of the cracks remained unchanged; after continued immersion in sodium chloride solution for 48 hours, no Brown rust oozed out, and the width of the crack remained the same; after soaking, the crack remained unchanged after 15 days, and the width of the crack remained the same.
  • the characteristics and preparation method of the concrete specimen of Example 2 are basically the same as those of Example 1. The difference is that, for the 20 steel fibers connecting the two parts of the test pieces A and B, the core fibers are steel fibers without copper plating protection, and the other conditions are the same as in Example 1.
  • the characteristics and preparation method of the concrete test piece of Example 3 are basically the same as those of Example 1. The difference is that the initial tensile stress of the core fiber of the 20 steel fibers connecting the two parts of the test pieces A and B is 1500 MPa at the time of preparation. The other conditions are the same as in Example 1.
  • test piece was immersed in a 6 wt% sodium chloride solution, and the detection result was basically the same as that of Example 1 under the condition that the detection conditions were completely consistent with Example 1.
  • the invention also tries to match the design of other core materials (such as mineral fiber, carbon fiber, glass fiber, basalt fiber, ceramic fiber, other metal fiber) and other easily corrosive coatings, and has also achieved good results.
  • other core materials such as mineral fiber, carbon fiber, glass fiber, basalt fiber, ceramic fiber, other metal fiber
  • the corrosion-driven smart fiber designed and prepared by the present invention exhibits excellent memory function under corrosive conditions, and it exhibits excellent crack closing function or crack self-healing function in concrete.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Architecture (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Structural Engineering (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Environmental Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Civil Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Ecology (AREA)
  • Pathology (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Bridges Or Land Bridges (AREA)
  • Working Measures On Existing Buildindgs (AREA)
  • Ropes Or Cables (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Reinforcement Elements For Buildings (AREA)

Abstract

一种腐蚀驱动智能纤维及其制备方法和应用。腐蚀驱动智能纤维由芯纤维和/或带耐腐涂层的芯纤维、易腐蚀涂层组成；芯纤维和/或带耐腐涂层的芯纤维沿纤维长度方向处于拉应力状态；易腐蚀涂层沿纤维长度方向处于压应力状态；且芯纤维和/或带耐腐涂层的芯纤维与易腐蚀涂层沿纤维长度方向处于拉压平衡状态；易腐蚀涂层包覆于芯纤维和/或带耐腐涂层的芯纤维外。其制备方法为：对芯纤维或带耐腐涂层的芯纤维施加拉力；然后在其表面设定区域制备易腐蚀涂层；卸除拉力，得到样品。其应用包括将其用于混凝土中。本发明首次提出了往混凝土加入带易腐蚀涂层的芯纤维，得到性能优越的产品。

Description

一种腐蚀驱动智能纤维及其制备方法和应用 技术领域
本发明涉及一种腐蚀驱动智能纤维及其制备方法和应用；属于土木工程技术领域。
背景技术
混凝土材料目前是世界上用量最大、应用最广泛的人造建筑材料，但是由于自身材料的性脆、抗拉强度低、极限延伸率小等缺点，在使用过程中和周围环境影响下极易产生裂缝和局部损伤，空气、水、氯离子等腐蚀性介质沿裂缝侵入结构内部腐蚀钢筋，降低工程结构的使用寿命，危及结构安全。随着工程建设技术的不断革新，水工大坝、铁路工程、公路桥梁、港口及海洋工程、隧道及矿井工程、管道工程、核电工程等对混凝土的性能提出更高的要求，因此纤维增强混凝土应运而生，通过投入纤维防止及抑止裂缝的形成及发展，提高混凝土的抗裂性能、韧性、及抗渗性等性能。
然而由于混凝土的低拉伸率、低强度的缺陷问题，即使采用如碳纤维、钢纤维等高强度、高弹性模量纤维也很难解决脆性开裂问题，而低模量的有机纤维更难解决该问题。主要由于混凝土构筑物在受到温度湿度的变化、不均匀沉降和外荷载作用下产生裂纹时，纤维却产生较小的应力，还远没达到自身的强度，随着开裂应力的增加，微观裂纹进一步增多和加宽。因此纤维的投入只能在较小的开裂应力范围内提高混凝土的抗裂性能和减少裂纹宽度，而且一旦出现裂纹，纤维无法修复和愈合裂纹，如果不能及时愈合裂纹，原有的微观裂纹发展成宏观裂纹，腐蚀介质通过这些裂纹进入建筑物内部快速锈蚀钢筋，进而影响建筑物的安全性和使用寿命。
混凝土裂缝的修复一直是学术界和工程界所关注和研究的热点，混凝土一旦出现裂缝，单纯通过人为检查和修复，不仅技术要求高而且实施困难、操作繁琐。因此自修复混凝土应运而生，纵观国内外相关文献关于水泥混凝土自修复方法的报道，目前主要有三大类：
1.1结晶沉积法；
该法按照修复机理分为矿物结晶沉淀法、水泥基渗透结晶法、微生物结晶法三种方法。
(1)矿物结晶沉淀法
机理：结晶沉淀法裂缝修复因素之一是裂隙水与未水化水泥颗粒和其他矿物添加剂(如C 3S、C 2S等)继续水化所生成的水化产物沉积修复裂缝，此修复作用影响甚微，但主导因素是溶水CO 2与微溶Ca(OH) 2生成CaCO3结晶沉淀，封堵愈合裂缝。
矿物结晶沉淀法存在的问题为：该法愈合功能受混凝土的龄期、裂纹尺寸、数量、分布以及特定的环境影响较大，愈合期较长，龄期较晚的混凝土愈合功能基本丧失，大于0.15mm宽度裂缝基本难以愈合。
(2)水泥基渗透结晶法
机理：水泥基渗透结晶型材料是由普通硅酸盐水泥，石英砂，带有活性功能基团的化学复合物组成，掺入渗透结晶型材料的混凝土干燥时，活性功能基团处于休眠状态，当混凝土开裂，有水渗入，缝隙处Ca 2+浓度降低一定程度时，活性功能基团发生缩聚反应生成新的结晶，快速对裂缝进行自动填充和修复。
水泥基渗透结晶法存在问题为：裂缝自修复宽度有限，对超过0.4mm宽度的裂缝修复效果欠佳。
(3)微生物结晶法
机理：微生物修复技术是将特定的无害细菌(好氧嗜碱芽孢杆菌)投入混凝土材料中，无损的混凝土其内部是高碱缺氧环境，该细菌处于休眠状态。当混凝土结构受损开裂，氧气和水分的渗入激活细菌孢子，其新陈代谢过程中产生CO 2与混凝土材料中的Ca 2+反应生成碳酸钙晶体，封填修复裂缝。
微生物结晶法存在的问题：自愈合裂缝宽度范围有限，仅能修复小于0.5mm的裂缝；该类细菌对工作环境和温度有一定的要求，服役时间和寿命较短(一年左右)。
1.2修复剂填充法
该法是种智能型仿生自愈合混凝土，按照修复剂载体的类型分为微胶囊法和空心纤维(空芯光纤或者中空纤维)法。
两者具有类似的修复机理：装载修复胶粘剂的微胶囊/空心纤维植入混凝土中，当混凝土结构在服役、使用过程中出现损伤和微裂纹时，裂纹所经之处，微胶囊/空心纤维破裂，修复剂从裂口流出渗入裂纹，与分散于混凝土中的催化剂相接触，固化硬结，快速封堵裂纹，实现自修复。
修复剂填充法存在的问题为：该方法是个很复杂的修复系统，修复剂涵盖有机合成、高分子化学、精细化工、微胶囊/空心纤维技术、埋植技术等，尚停留在实验研究阶段，存在颇多待解问题，主要有：①载体投入的数量问题，数量过多影响混凝土自身的强度，数量太小不足以填塞缝隙；②载体的断裂应变问题，断裂应变过大，载体不宜撕裂，胶液不能及时流出，过小导致载体在搅拌时易破碎，导致胶液提前流出；③混凝土基体、修复剂载体和胶粘剂之间的相容性，修复剂的长期稳定性，在裂缝的流动性、固化时效性等等问题；
1.3形状记忆合金驱动闭合法(SMA法)
该法是配合修复剂填充法而生，为了取得理想的自修复效果，混凝土的裂缝宽度必须控制，否则的话，将需要大量的修复载体，这将影响混凝土的性能。此外，当混凝土的裂缝过宽时，毛细吸力降低，纤维管上方的裂缝吸存胶液困难，胶液在重力作用下顺缝往下流出，残留在裂缝面胶液少，修复效果差，因此要想达到理想的自修复效果，必须控制混凝土的裂缝宽度。现有的能够感受外部刺激主动变形，能提供驱动力的智能材料——形状记忆材料主 要有形状记忆合金、形状记忆聚合物，但记忆聚合物形变回复力小不适合做自愈合驱动，而形状记忆合金由于强度高、回复力大可以做自愈合驱动。
机理：SMA法通过对预埋在混凝土内部的形状记忆合金丝通电加热激励其收缩变形，为裂缝的闭合提供驱动力。该法通过对结构施加预压力主动调节裂缝宽度，是上述几种方法无法触及的。
形状记忆合金驱动闭合法存在的问题为：由于形状记忆合金是热致形变材料，需要通电加热激励合金丝收缩，驱动裂缝闭合需要一系列配套设备，整个驱动和控制系统复杂而繁琐。由于SMA材料本身的电阻不大，通电加热需要较大的电流，对电源和导线要求都很高。加热温度的高低对SMA形状回复和混凝土的力学性能都有较大影响，由于混凝土的热传导，SMA温度调控有技术难度，温度过低SMA难以驱动，升温过高和升温不均匀都会导致混凝土再次出现温度裂纹。另外，驱动裂纹闭合，实现自修复，需要投入大量的SMA，而SMA价格昂贵，是普通钢材价格的700倍，就这一点就足以扼杀SMA法在混凝土中的应用。
综合上述，为了降低混凝土结构因裂纹缺陷造成的经济损失和安全威胁，修复混凝土的裂纹缺陷危害刻不容缓，目前的修复方法中，水泥基渗透结晶型材料应用是比较成功的智能型修复材料，但修复效果受到裂缝宽度的限制，其他方法基本上因修复机理过于复杂则停留在实验探索阶段，或者修复效果欠佳。因此，要想达到理想的自修复效果，混凝土的裂缝宽度控制非常重要。
发明内容
本发明针对现有技术的不足，提出了一种腐蚀驱动智能纤维及其制备方法和应用。
本发明一种腐蚀驱动智能纤维；所述腐蚀驱动智能纤维由芯纤维和/或带耐腐涂层的芯纤维、易腐蚀涂层组成；所述芯纤维和/或带耐腐涂层的芯纤维沿纤维长度方向处于拉应力状态；所述易腐蚀涂层沿纤维长度方向处于压应力状态；且芯纤维和/或带耐腐涂层的芯纤维与易腐蚀涂层沿纤维长度方向处于拉压平衡状态；所述易腐蚀涂层包覆于芯纤维和/或带耐腐涂层的芯纤维外。
作为优选方案，在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于芯纤维；和/或，在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于带耐腐涂层的芯纤维的腐蚀速率。
作为优选方案，本发明一种腐蚀驱动智能纤维；
所述腐蚀驱动智能纤维包括芯纤维和易腐蚀涂层,芯纤维外的部分位置或全部位置上包覆有易腐蚀涂层；
或
所述腐蚀驱动智能纤维包括耐腐涂层、芯纤维和易腐蚀涂层；所述芯纤维外的部分位置或全部位置上包覆有耐腐涂层；当芯纤维外的部分位置或全部位置上包覆有耐腐涂层时，所得材料定义为A；在A表面的部分位置或全部位置上包覆易腐蚀涂层，
或
所述腐蚀驱动智能纤维包括芯纤维、易腐蚀涂层、耐腐涂层；所述芯纤维外包覆有易腐蚀涂层；所述易腐蚀涂层的部分位置上包覆有耐腐涂层；
或
所述腐蚀驱动智能纤维包括芯纤维和易腐蚀涂层,芯纤维外的部分位置或全部位置上包覆有易腐蚀涂层；所述芯纤维外的部分位置包括芯纤维的端部；当芯纤维的端部包覆有易腐蚀涂层时，在端部的易腐蚀涂层外还包覆有耐腐涂层；
或
所述腐蚀驱动智能纤维包括耐腐涂层、芯纤维和易腐蚀涂层；所述芯纤维外的部分位置或全部位置上包覆有耐腐涂层；当芯纤维外的部分位置或全部位置上包覆有耐腐涂层时，所得材料定义为A；在A表面的部分位置或全部位置上包覆易腐蚀涂层，当A的端部包覆有易腐蚀涂层时，在端部的易腐蚀涂层外还包覆有耐腐涂层；
其中，芯纤维和/或带耐腐涂层的芯纤维沿纤维长度方向处于拉应力状态；所述易腐蚀涂层沿纤维长度方向处于压应力状态；
在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于芯纤维；和/或，在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于带耐腐涂层的芯纤维的腐蚀速率。
本发明一种腐蚀驱动智能纤维；所述芯纤维选自无机纤维、聚合物纤维中的至少一种；所述芯纤维的当量直径小于等于20mm，优选为小于等于5mm。所述的当量直径为纤维横截面面积换算成圆截面的直径。
本发明一种腐蚀驱动智能纤维；所述无机纤维选自C纤维、玻璃纤维、矿物纤维、玄武岩纤维、陶瓷纤维、金属纤维中的至少一种；所述金属纤维选自钢纤维、镀M钢纤维、不锈钢纤维、铜合金纤维、钛合金纤维、镍合金纤维中的至少一种；所述的M选自铜、镍、铬、锡、镉、银元素中的至少一种。
所述聚合物纤维选自聚丙烯纤维、聚丙烯腈纤维、聚乙烯醇纤维、聚乙烯纤维、芳纶纤维、涤纶纤维、锦纶纤维中的至少一种。
本发明一种腐蚀驱动智能纤维；所述耐腐涂层的材质选自铜、镍、铬、镉、银、金元素中的至少一种。当芯纤维为钢制纤维时，其耐腐涂层的材质选自铜、镍、铬、镉、银、金元素中的至少一种。当芯纤维为钢制纤维时，通过施镀或涂覆的方式制备耐腐蚀涂层。
本发明一种腐蚀驱动智能纤维；所述芯纤维或者包覆有耐腐涂层的芯纤维，其标准电极电位大于易被腐蚀涂层，或者其活泼性小于易被腐蚀涂层。
本发明一种腐蚀驱动智能纤维；所述腐蚀驱动智能纤维包括易腐蚀涂层、芯纤维或者带耐腐涂层的芯纤维,芯纤维或者带耐腐涂层的芯纤维的侧面包覆有易腐蚀涂层；
或
所述腐蚀驱动智能纤维包括易腐蚀涂层、芯纤维或者带耐腐涂层的芯纤维,芯纤维或者带耐腐涂层的芯纤维除锚固端之外的侧面包覆有易腐蚀涂层。
本发明一种腐蚀驱动智能纤维；所述易腐蚀涂层为铁金属或者铁合金，芯纤维为钢纤维，耐腐涂层为铜金属或者铜合金。
本发明一种腐蚀驱动智能纤维的制备方法；对芯纤维或带耐腐涂层的芯纤维施加拉力；然后在其表面设定区域制备易腐蚀涂层；卸除拉力，得到样品；所施加的拉力为芯纤维或带耐腐涂层的芯纤维承载力的10％至90％。在制备方法中所述的带耐腐涂层的芯纤维，其至少包括两种情况，情况一，耐腐蚀涂层均匀包覆于芯纤维表面，情况二，在芯纤维表面设定区域涂覆耐腐蚀涂层。在工业上应用时，如果需要在端部设置耐腐蚀涂层；则在所得样品的端部再涂覆一层耐腐蚀涂层。
当易腐蚀涂层的局部位置需要包覆耐腐涂层时，在样品表面的设定位置直接制备耐腐涂层即可。
本发明一种腐蚀驱动智能纤维的制备方法；在整个腐蚀驱动智能纤维中，为了使智能纤维对外界施加的预应力达到最大，其优化获取方法为：
腐蚀驱动智能纤维的横截面面积一定情况下，
智能纤维的预应力存储的大小与芯纤维的体积分数V f密切相关，芯纤维存储的轴向力F为：
Figure PCTCN2019091912-appb-000001
当F达到最大时，智能纤维对外界的预应力作用将达到最大；
求芯纤维的轴向力的最值，首先对F求导，得：
Figure PCTCN2019091912-appb-000002
即：
Figure PCTCN2019091912-appb-000003
令F′＝0，则：
(E c-E f)V f 2-2E cV f+E c＝0          (14)
当E c＝E f时，得
Figure PCTCN2019091912-appb-000004
此时F可以取最值，即得到Fmax；
当E c≠E f时，对于方程
Figure PCTCN2019091912-appb-000005
令
Figure PCTCN2019091912-appb-000006
由于E c＞0，E f＞0，则a＜0或者a＞1，那么有Δ＝4a 2-4a＞0，原方程有两个不同的实根，即：
Figure PCTCN2019091912-appb-000007
又由于0＜V f＜1，而当E c＜E f时，则
Figure PCTCN2019091912-appb-000008
当E c＞E f时，
Figure PCTCN2019091912-appb-000009
则实根
Figure PCTCN2019091912-appb-000010
不满足0＜V f＜1的条件，应该舍去；而当
Figure PCTCN2019091912-appb-000011
V f满足16式的条件，使F可以取最大值，即得到Fmax。
本发明一种腐蚀驱动智能纤维的应用：包括将其用于混凝土或纤维增强树脂复合材料中。
本发明一种腐蚀驱动智能纤维的应用：当将所述腐蚀驱动智能纤维用于混凝土时，其腐蚀驱动条件为混凝土的使用环境。在混凝土的使用环境中，H 2O/O 2、Cl -、SO 4 -2等为主要的腐蚀性介质，或者酸性腐蚀性物质为主要的腐蚀性介质。这些腐蚀性介质是驱动腐蚀驱动智能纤维展现出智能化的先决条件之一。在工业或者工程上应用时，根据混凝土的服役环境进一步调整智能纤维的芯纤维材质、耐腐蚀涂层材质和易腐蚀涂层材质。
本发明一种腐蚀驱动智能纤维的应用：腐蚀驱动智能纤维锚固于混凝土中。锚固方式可以为粘结锚固和/或机械锚固中的至少一种。
本发明一种腐蚀驱动智能纤维的应用：将所述腐蚀驱动智能纤维用于混凝土中时，其用量为0.01～20v％。
本发明一种腐蚀驱动智能纤维的应用：所述易腐蚀涂层的材质优选为易腐蚀的铁金属材料(如单质铁、低碳铁、铁合金等)、掺杂有害物质(如碳、氮、磷和硅等有害微量元素)容易形成电化学腐蚀的铁基金属材料或者容易形成晶间腐蚀的合金。
本发明所述易腐蚀涂层可为单层材料、多层材料或者功能梯度材料构成。
本发明所述腐蚀驱动智能纤维的截面形状可以是圆形、多边形、异形截面(包括槽形、十字形、井字形、三叶形、梅花形或星形)，轴向线形可是波浪，表面可以是压痕或者带肋形状。
本发明所述腐蚀驱动智能纤维可以由单根纤维构成或者由多根纤维经过加捻和并股而成的绞线构成。
本发明所述腐蚀驱动智能纤维中的芯纤维可以由单根纤维构成或者由多根纤维经过加捻和并股而成的绞线构成。
本发明所述腐蚀驱动智能纤维在目标体形成锚固端的形式，有全镀端钩型，裸露端直钩型，裸露端弯钩型，端部墩头锚型，端部扁头锚型。
本发明所述腐蚀驱动智能纤维外形为平直形、压棱形、波形、弯钩形、大头形、双大头形、双尖形或集束型。
在本发明中，所有或部分涂层可以是多层，也可以是复合涂层。
本发明为了防止易腐蚀涂层被腐蚀殆尽时，芯纤维与混凝土失去了锚固传力点，导致芯纤维作用再混凝土上的力失效，为了芯纤维的作用力永久有效，最好是在纤维的端部设置锚固端，或者在较长的智能纤维上设置多个部位设立锚固点，如图7所示。
本发明一种腐蚀驱动智能纤维的应用；将所述腐蚀驱动智能纤维用于混凝土中时，其施工、护养方式和现有混凝土的完全一致。
原理和优势
本发明首次提出了往混凝土加入带腐蚀涂层的芯纤维；通过混凝土的锚固作用，在使用过程中，前期抗腐蚀和阻止开裂的能力和现有混凝土相当；当一旦带腐蚀涂层的芯纤维开始腐蚀时，其就展现出逐步修复已产生裂纹的功能直至裂纹完全闭合；这就大大延长了混凝土的使用寿命。同时往混凝土加入带腐蚀涂层的芯纤维还可以降低混凝土过早开裂几率，提高混凝土结构的力学性能、耐久性和使用安全，对提高低模量聚合物纤维混凝土构件抗裂性有很大的帮助。
本发明提出了一种腐蚀驱动智能纤维及自愈合混凝土，其原理是在预张拉的芯纤维表面涂覆的易腐蚀涂层制备出一种智能纤维(其中芯纤维不易被腐蚀，易腐蚀涂层容易被腐蚀)，通过环境中腐蚀性介质的腐蚀激发智能纤维形状回复，给混凝土施加预压力，为混凝土的裂纹闭合提供动力，而且当易腐蚀涂层腐蚀越严重，施加的预应力就越大，当预应力足够大时，裂纹被愈合。预应力的施加可以提高混凝土结构的力学性能、耐久性和使用安全，为形状记忆材料提供一种全新的设计思路，为混凝土等复合材料的自修复、自愈合提供一种全新的理念。
本发明提出了一种具有腐蚀驱动形状记忆功能纤维，通过环境中进入混凝土的腐蚀性介质驱动智能纤维发生收缩形变，对混凝土施加预应力，机械闭合混凝土裂纹，为混凝土的智能自愈合提供全新的方法，为在混凝土材料中任意位置、任意方向施加预应力提供了一种全新思路。
本发明腐蚀驱动智能纤维的制备及其自愈合混凝土的基本原理
制备方法
腐蚀驱动智能纤维(本发明简称智能纤维)由芯纤维和易腐蚀涂层构成，其中，芯纤维材料由耐腐蚀的材料或者涂有耐腐蚀涂层的材料构成，易腐蚀涂层材料则由容易被环境中腐蚀性介质腐蚀的材料构成。智能纤维的制备方法如图1所示，制备步骤从a～d依次进行。
图1中，a表示芯纤维处在无应力状态；b表示在弹性范围对芯纤维进行预张拉，张拉应力为σ o；c表示芯纤维拉应力σ o不变的情况下，在其表面沉积、喷涂或者电镀等方法均匀涂覆易腐蚀涂层，此时易腐蚀涂层处在无应力状态；d表示，待涂层涂覆完毕后，卸除张拉力，假设芯纤维与易腐蚀涂层结合良好，在卸除的过程中，易腐蚀涂层在芯纤维的弹性回复力作用下沿轴向回缩，产生的压应力为
Figure PCTCN2019091912-appb-000012
最终两者建立拉压力平衡，易腐蚀涂层存储预压应力和相应的预压应变，芯纤维存储预拉应力和相应的预拉应变。
形状回复机理
智能纤维形状回复机理如图2所示，在腐蚀性介质环境下，当易腐蚀涂层受腐蚀出现截面损失时，智能纤维则开始回复，回复流程从a～c依次进行。图a表示智能纤维未被腐蚀的状态，芯纤维和易腐蚀涂层处于原始平衡状态；图b表示，在腐蚀性介质环境下，易腐蚀涂层首先与腐蚀性介质接触，被腐蚀生成难以承受荷载的腐蚀产物，而芯纤维抗腐蚀能力强，截面和强度不会出现损失，由于易腐蚀涂层受腐蚀后有效受力截面厚度变小，在芯纤维弹性回复力作用下，剩余易腐蚀涂层的压应力和压缩变形不断增大，芯纤维随之不断收缩，逐渐接近初始长度；如图c所示，当易腐蚀涂层被腐蚀殆尽后，芯纤维回复至初始长度，完成一次单程记忆效应，此时的芯纤维处于无应力状态。
因此，腐蚀驱动智能纤维具备形状记忆功能需要满足两个基本条件：
1、芯纤维沿轴向储存有预拉应变，易腐蚀涂层储存有预压应变，两者处于拉压平衡状态；
2、易腐蚀涂层材料需要由容易被环境中腐蚀性介质腐蚀的材料构成，而芯纤维则由耐腐蚀的材料或者涂有耐腐蚀涂层的材料构成。
自愈合混凝土的基本原理
智能纤维施加预应力的基本条件和原理
混凝土结构受到温、湿度和外力等因素出现裂纹，裂纹缺陷处的智能纤维受到来自环境中腐蚀性介质的腐蚀，形状回复受到激发，给混凝土施加预压力，为裂纹的闭合提供动力。腐蚀驱动型智能纤维自愈合原理如图3所示，自愈合过程从a～c依次进行。图a表示混凝土出现裂纹，但智能纤维还未受到腐蚀，处于稳定状态。图b表示裂纹处的易腐蚀涂层与腐蚀性介质发生化学或者电化学反应，智能纤维受激回缩，通过粘结区(暂未被腐蚀的易腐蚀涂层与混凝土的粘结锚固界面)传递荷载，对混凝土施加预压力，易腐蚀涂层的腐蚀程度越 高，闭合力越大，裂纹宽度也就越小。如图c所示，当易腐蚀涂层腐蚀一定程度后，作用在裂缝面上的闭合力足够大时，裂纹闭合，腐蚀性介质入内通道被切断，腐蚀停止，实现自愈合保护功能，此时，芯纤维的回缩力和预压力停止增加。
但如果存在孔洞之类的缺陷，仍然可能使腐蚀性介质进入材料内部继续腐蚀智能纤维，易腐蚀涂层与混凝土的粘结锚固界面不断减少，混凝土的预压力和预应力区域不断增加，当锚固界面不足以承担智能纤维回缩引起的拉拔力时，导致智能纤维拔出，预应力施加失效。或者当裂纹靠近智能纤维端部，端部区域易腐蚀涂层表面受到腐蚀，端部锚固失效，造成智能纤维无法有效对混凝土施加预应力，导致裂纹重新张开。
为了使智能纤维更有效的对混凝土施加预应力，最好在智能纤维的端部留置可靠的锚固端，如图3所示，在芯纤维的两端部留置无涂层的裸露端，或者在两端留置端钩，保证锚固端的可靠性。不管是裂纹分布在纤维的端部，还是易腐蚀涂层全部被腐蚀殆尽，但有了可靠的锚固端就可以使纤维难以被拔出，保障预应力的有效性，提高了混凝土的抗裂性能。
智能纤维及混凝土的内力理论计算
智能纤维的内力理论计算
基本假定
由于智能纤维为长细比足够大的单向复合材料，为了简化计算智能纤维的内力，可做如下假设：
1)易腐蚀涂层在芯纤维上涂覆均匀；
2)芯纤维与易腐蚀涂层的界面结合良好且两者具有良好的化学相容性；
3)忽略芯纤维和易腐蚀涂层的横向应变的影响，公式推导中不计入泊松比；
4)芯纤维与易腐蚀涂层的受力处于线弹性状态；
5)结构单元受拉为正，受压为负。
智能纤维内力公式推导
如图4，设芯纤维原始长度为l，对芯纤维进行张拉，张拉应力为σ o，伸长量为Δx 1。沉积后的涂层长度为l+Δx 1，卸除芯纤维的张拉力，由于芯纤维的回复力，涂层的压缩变形量为Δx 2，两者达到力的平衡和协调变形，根据虎克定律：
芯纤维的张拉力：
Figure PCTCN2019091912-appb-000013
易腐蚀涂层的压力：
Figure PCTCN2019091912-appb-000014
由力的平衡,F f+F c＝0，则
Figure PCTCN2019091912-appb-000015
即
Figure PCTCN2019091912-appb-000016
又由于：
Figure PCTCN2019091912-appb-000017
将式(4)代入式(5)得：
Figure PCTCN2019091912-appb-000018
令智能纤维的截面面积A＝A c+A f，而
Figure PCTCN2019091912-appb-000019
将式(6)的右边的分子分母同除以Al，则
Figure PCTCN2019091912-appb-000020
又
Figure PCTCN2019091912-appb-000021
代入式(7)，易腐蚀涂层的压应力：
Figure PCTCN2019091912-appb-000022
由于σ o远小于E f，所以：
Figure PCTCN2019091912-appb-000023
此时，芯纤维储存的预应力表达式为：
Figure PCTCN2019091912-appb-000024
本发明所有公式中：
σ o为芯纤维的初始张拉应力值；
Figure PCTCN2019091912-appb-000025
为易腐蚀涂层的预应力值；
E 1＝E fV f+E cV c为智能纤维的弹性模量(复合弹性模量)。
E c，E f分别为易腐蚀涂层和芯纤维的弹性模量(当芯纤维附带耐腐蚀涂层时，其弹性模量按照复合弹性模量计算公式计算)；
V c，V f分别为易腐蚀涂层和芯纤维的体积分数，V c+V f＝1；
A c，A f分别为易腐蚀涂层和芯纤维的截面面积，A c+A f＝A；
ε c为易腐蚀涂层平衡后的应变；ε f为芯纤维的初始拉应变。
智能纤维预应力储存最优化
对于相同截面面积的智能纤维，智能纤维预应力存储的大小与芯纤维的体积分数V f密切相关，芯纤维存储的轴向力F为：
Figure PCTCN2019091912-appb-000026
当F达到最大时，智能纤维对外界的预应力作用将达到最大。
求芯纤维的轴向力的最值，首先对F求导，得：
Figure PCTCN2019091912-appb-000027
即：
Figure PCTCN2019091912-appb-000028
令F′＝0，则：
(E c-E f)V f 2-2E cV f+E c＝0               (14)
当E c＝E f时，得
Figure PCTCN2019091912-appb-000029
此时F可以取最值。
当E c≠E f时，对于方程
Figure PCTCN2019091912-appb-000030
令
Figure PCTCN2019091912-appb-000031
由于E c＞0，E f＞0，则a＜0或者a＞1，那么有Δ＝4a 2-4a＞0，原方程有两个不同的实根，即：
Figure PCTCN2019091912-appb-000032
又由于0＜V f＜1，而当E c＜E f时，则
Figure PCTCN2019091912-appb-000033
当E c＞E f时，
Figure PCTCN2019091912-appb-000034
则实根
Figure PCTCN2019091912-appb-000035
不满足0＜V f＜1的条件，应该舍去；而当
Figure PCTCN2019091912-appb-000036
V f满足16式的条件，使F可以取最大值，即Fmax。
在工程上应用时，如果公式16的计算值不在5v％～95v％的范围内时，最好将芯纤维的体积分数V f调整为5v％～95v％。
智能纤维混凝土的内力计算
为了确保智能纤维在复杂工况下能持续发挥作用，将留有永久锚固端的智能纤维掺入混凝土中，智能纤维发生形状回复时对混凝土施加的预应力进行预测。所述永久锚固端为一下两种情况：
情况一所述腐蚀驱动智能纤维由芯纤维和易腐蚀涂层构成；所述芯纤维表面部分位置不包覆易腐蚀涂层，且所述芯纤维位于混凝土中，此时芯纤维未包覆易腐蚀涂层的部位即为永久锚固端，其中任意一个永久锚固端的长度定义为l′；
情况二所述腐蚀驱动智能纤维由芯纤维、易腐蚀涂层、耐腐蚀涂层构成；所述永久锚固端为芯纤维表面包覆易腐蚀涂层且包覆易腐蚀涂层外包覆有耐腐蚀涂层的部位；同时所述芯纤维位于混凝土中，其中任意一个永久锚固端的长度定义为l；
为了简化计算，不计泊松比对轴向应力大小的影响。
基本假定
为了简化计算智能纤维与混凝土中的相互作用力，做如下假设：
1)智能纤维单向均匀布置在混凝土构件中；
1)不计泊松比对轴向应力大小的影响；
2)永久锚固端与混凝土结合紧密，无滑移；
3)不计易腐蚀涂层腐蚀产物的受力影响；
混凝土的预压力
当易腐蚀涂层截面全部损失后，由于腐蚀产物不参与受力，芯纤维与混凝土两者建立最终的拉压平衡，此时芯纤维回缩对混凝土施加的预应力达到最大。根据式(9)，可知芯纤维回缩对混凝土施加的预压应力
Figure PCTCN2019091912-appb-000037
为：
Figure PCTCN2019091912-appb-000038
芯纤维的拉应力为：
Figure PCTCN2019091912-appb-000039
为了使永久锚固端可靠而不滑移，则需要足够的长度，设永久锚固端的粘结锚固力为T a＝τπdl′，智能纤维的拉拔力为
Figure PCTCN2019091912-appb-000040
根据永久锚固端的粘结锚固力与智能纤维的拉拔力的平衡，T a＝T t，即，
Figure PCTCN2019091912-appb-000041
得：
Figure PCTCN2019091912-appb-000042
将(18)式代入(19)式得：
Figure PCTCN2019091912-appb-000043
如果使永久锚固端可靠而不滑移，则
Figure PCTCN2019091912-appb-000044
其中，
芯纤维与混凝土的复合弹性模量为：
Figure PCTCN2019091912-appb-000045
混凝土的弹性模量为：E m；
成品中，芯纤维、易腐蚀涂层和混凝土的体积分数分别为：V f1、V c1、V m，V f1+V c1＝V s，V f1+V c1+V m＝1。
τ为智能纤维与混凝土界面结合的粘结力(当混凝土成分、智能纤维的成分和结构确定后，其为已知量)，l′为永久锚固端在混凝土中的锚固长度(一端的长度)，d为锚固端截面直径。
附图说明
附图1为智能纤维制备过程示意图；
附图2为腐蚀驱动智能纤维的形状回复机理图；
附图3为腐蚀驱动型智能纤维自愈合原理图；
附图4为芯纤维弹性回复力的作用下易腐蚀涂层的受力平衡过程图；
附图5为实施例1计算过程中智能纤维的掺量和初始张应力的变化对混凝土预应力的影响图。
附图6为本发明所设计的智能纤维的几种结构示意图。
附图7为锚固点的布置图。
附图8为实施例1的混凝土试件结构示意图。
具体实施方式
材料基本参数
根据上述内力计算公式，智能纤维的芯纤维采用镀铜钢纤维(直径0.2mm、镀铜量忽略不计)，易腐蚀涂层采用金属铁，当芯纤维和易腐蚀涂层的截面面积为1:1时，智能纤维的预应力储存达到最大。智能纤维在混凝土的掺量为4v％，智能纤维和混凝土的基本参数如表1。
表1 易腐蚀涂层、芯纤维和混凝土的材料基本参数
Figure PCTCN2019091912-appb-000046
预应力完全释放时混凝土的轴向应力情况
假设智能纤维在混凝土中单向均匀布置，易腐蚀涂层截面损失殆尽，智能纤维形状回复对混凝土施加的预应力达到最大值。
芯纤维存储的应力：
Figure PCTCN2019091912-appb-000047
芯纤维回缩对混凝土施加的预应力为：
Figure PCTCN2019091912-appb-000048
从上述的计算结果可知，4％掺量的智能纤维对混凝土释放最大的预压应力达到9.3MPa，如果继续增大智能纤维记的体积分数和芯纤维的初始张拉力，那么给混凝土施加的预应力将继续增大。
如图5所示，当智能纤维的体积分数V s和芯纤维的初始张拉力σ o的不断增大时，基体的预压应力也不断增大。因此，预应力的大小可以通过智能纤维初始拉应力的大小和体积分数进行控制，预应力的施加对混凝土的裂纹闭合、应力集中的减小、刚性增大、抗腐蚀性能的提高、韧性提高都是有利的。预应力的存在对混凝土构件，尤其对低模量聚合物纤维混凝土构件抗裂性有很大的帮助。
按照上述设计和计算，制备出如下混凝土试件：
实施例1
如图8所示，混凝土试件的特征如下，混凝土试件的尺寸为200mm×20mm×40mm(长×宽×高)，被一块垂直于试件长度方向、厚度为0.3mm的吸水绵纸平分成两A和B两部分，吸水绵纸模拟试件的贯穿裂缝，形成腐蚀介质通道。试件的A和B两部分由20根长度为180mm、直径为0.28mm的形状记忆钢纤维连接，每根智能纤维的芯纤维采用直径为0.2mm、强度为3000MPa的镀铜钢纤维，芯纤维的初始张拉应力为2000Mpa，易腐蚀涂层为电镀铁金属，厚度为0.04mm。20根纤维靠边排布并垂直穿过吸水绵纸，每根纤维的中间段包裹长度为50mm、厚度为0.2mm的吸水绵纸作为吸水的通道，以增加智能纤维易腐蚀层的腐蚀速度，加快形状智能纤维的回复速度。
将试件浸泡于6wt％的氯化钠溶液中，经48小时后发现裂缝处出现少量棕褐色铁锈渗出，经测量发现裂纹的宽度变窄；清理试件的A和B两部之间吸水绵纸上铁锈，然后继续在氯化钠溶液中浸泡48小时后，发现裂缝处绵纸渗出的棕褐色铁锈较上次变少，经测量发现裂缝的宽度进一步变窄；继续浸泡，15天后，发现裂缝处无棕褐色铁锈渗出，裂缝基本闭合。表明，腐蚀驱动形状记忆钢纤维在氯化钠溶液发生电化学腐蚀(铁涂层发生锈蚀)，在电化学腐蚀的驱动下智能纤维形状回复，产生的回复力使试件的A和B部分相互靠拢，挤压腐蚀介质通道——吸水绵纸，使其变薄，降低吸水绵纸的流通性。当智能纤维的铁涂层锈蚀越严重，智能纤维的回复力就越大，最终使吸水绵纸被挤压至不再具有流通性，使贯穿裂缝闭合，腐蚀介质无法进入试件内部，形成自愈合。
对比例1
对比例1的混凝土试件特征和制备方法与实施例1基本相同。区别在于，连接试件A和B两部分的20根钢纤维，其芯纤维的初始张拉应力为0Mpa，即在无张力的情况下电镀0.04mm厚的铁涂层。
将对比例1的混凝土试件浸泡于6％的氯化钠溶液中，经48小时后发现裂缝处出现少量棕褐色铁锈渗出，经测量发现裂纹的宽度无变化；清理试件的A和B两部之间吸水绵纸上铁锈，然后继续在氯化钠溶液中浸泡48小时后，发现裂缝处绵纸有棕褐色的铁锈渗出，经测量发现裂缝的宽度未见变窄；继续浸泡，15天后，发现裂缝处的棕褐色铁锈任然渗出，裂缝宽度基本不变。实验结果发现这20根钢纤维不具有形状记忆功能，导致吸水绵纸形成的贯穿裂 缝不能被闭合，表明采用在无张力的情况下电镀铁涂层制备得到的钢纤维不具有记忆功能，无法愈合混凝土裂缝。
对比例2
对比例2的混凝土试件特征和制备方法与实施例1基本相同。区别在于，连接试件A和B两部分的20根钢纤维，其芯纤维的初始张拉应力为0Mpa，即在无张力的情况下电镀0.04mm厚的铜涂层。
将对比例2的混凝土试件浸泡于6％的氯化钠溶液中，经48小时后发现裂缝处无异常变化，裂纹的宽度保持不变；继续在氯化钠溶液中浸泡48小时后，无棕褐色的铁锈渗出，裂缝宽度保持不变；继续浸泡，15天后，裂缝处任然无变化，裂缝宽度保持不变。实验结果发现这20根钢纤维不具有形状记忆功能，导致吸水绵纸形成的贯穿裂缝不能被闭合，表明采用电镀铜涂层制备得到的钢纤维不具有记忆功能，无法愈合混凝土裂缝。
对比例3
对比例3的混凝土试件特征和制备方法与实施例1基本相同。区别在于，连接试件A和B两部分的20根钢纤维，其芯纤维的初始张拉应力为2000Mpa，即在无张力的情况下电镀0.04mm厚的铜涂层。
将对比例3的混凝土试件浸泡于6％的氯化钠溶液中，经48小时后发现裂缝处无异常变化，裂纹的宽度保持不变；继续在氯化钠溶液中浸泡48小时后，无棕褐色的铁锈渗出，裂缝宽度保持不变；继续浸泡，15天后，裂缝处任然无变化，裂缝宽度保持不变。实验结果发现这20根钢纤维不具有形状记忆功能，导致吸水绵纸形成的贯穿裂缝不能被闭合，表明采用在张拉力的情况下电镀铜涂层制备得到的钢纤维不具有记忆功能，无法愈合混凝土裂缝。
实施例2
实施例2的混凝土试件特征和制备方法与实施例1基本相同。区别在于，连接试件A和B两部分的20根钢纤维，其芯纤维采用无镀铜保护的钢纤维，其它情况与实施例1相同。
将试件浸泡于6％的氯化钠溶液中，经48小时后发现裂缝处出现少量棕褐色铁锈渗出，经测量发现裂纹的宽度变窄；清理试件的A和B两部之间吸水绵纸上铁锈，然后继续在氯化钠溶液中浸泡48小时后，发现裂缝处绵纸渗出的棕褐色铁锈较上次变少，经测量发现裂缝的宽度进一步变窄；继续浸泡，15天后，发现裂缝张开，裂缝最宽度处达0.5mm，较初始裂缝变宽了0.2mm，而且有5根钢纤维发生断裂。实验结果发现这20根钢纤维虽然具有形状记忆功能，但是由于芯纤维的表面未有镀铜，使芯纤维发生电化学腐蚀而断裂，导致吸水绵纸形成的贯穿裂缝重新张开，无法继续为混凝土裂缝的愈合提供闭合力。
实施例3
实施例3的混凝土试件特征和制备方法与实施例1基本相同。区别在于，连接试件A和B两部分的20根钢纤维，其在制备时，芯纤维的初始张拉应力为1500Mpa，其它情况与实施例1相同。
将试件浸泡于6wt％的氯化钠溶液中，在检测条件与实施例1完全一致情况下，其检测结果与实施例1基本一致。
本发明还尝试了其他芯材(如矿物纤维、碳纤维、玻璃纤维、玄武岩纤维、陶瓷纤维、其他金属纤维)和其他易腐蚀涂层的搭配设计，也取得了不错的效果。
综述所述，本发明所设计和制备的腐蚀驱动智能纤维在腐蚀条件下展现出优异的记忆功能，其用于混凝土中展现出优异的裂纹闭合功能或裂纹自愈合功能。

Claims (13)

  1. 一种腐蚀驱动智能纤维；其特征在于：所述腐蚀驱动智能纤维由芯纤维和/或带耐腐涂层的芯纤维、易腐蚀涂层组成；所述芯纤维和/或带耐腐涂层的芯纤维沿纤维长度方向处于拉应力状态；所述易腐蚀涂层沿纤维长度方向处于压应力状态；且芯纤维和/或带耐腐涂层的芯纤维与易腐蚀涂层沿纤维长度方向处于拉压平衡状态；所述易腐蚀涂层包覆于芯纤维和/或带耐腐涂层的芯纤维外；所述腐蚀驱动智能纤维由单根纤维构成或者由多根纤维经过加捻和并股而成的绞线构成。
  2. 根据权利要求1所述的一种腐蚀驱动智能纤维；其特征在于：
    在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于芯纤维；和/或，在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于带耐腐涂层的芯纤维的腐蚀速率。
  3. 根据权利要求1所述的一种腐蚀驱动智能纤维；其特征在于：
    所述腐蚀驱动智能纤维包括芯纤维和易腐蚀涂层,芯纤维外的部分位置或全部位置上包覆有易腐蚀涂层；
    或
    所述腐蚀驱动智能纤维包括耐腐涂层、芯纤维和易腐蚀涂层；所述芯纤维外的部分位置或全部位置上包覆有耐腐涂层；当芯纤维外的部分位置或全部位置上包覆有耐腐涂层时，所得材料定义为A；在A表面的部分位置或全部位置上包覆易腐蚀涂层，
    或
    所述腐蚀驱动智能纤维包括芯纤维、易腐蚀涂层、耐腐涂层；所述芯纤维外包覆有易腐蚀涂层；所述易腐蚀涂层的部分位置上包覆有耐腐涂层；
    或
    所述腐蚀驱动智能纤维包括芯纤维和易腐蚀涂层,芯纤维外的部分位置或全部位置上包覆有易腐蚀涂层；所述芯纤维外的部分位置包括芯纤维的端部；当芯纤维的端部包覆有易腐蚀涂层时，在端部的易腐蚀涂层外还包覆有耐腐涂层；
    或
    所述腐蚀驱动智能纤维包括耐腐涂层、芯纤维和易腐蚀涂层；所述芯纤维外的部分位置或全部位置上包覆有耐腐涂层；当芯纤维外的部分位置或全部位置上包覆有耐腐涂层时，所得材料定义为A；在A表面的部分位置或全部位置上包覆易腐蚀涂层，当A的端部包覆有易腐蚀涂层时，在端部的易腐蚀涂层外还包覆有耐腐涂层；
    其中，芯纤维和/或带耐腐涂层的芯纤维沿纤维长度方向处于拉应力状态；所述易腐蚀涂层沿纤维长度方向处于压应力状态；
    在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于芯纤维；和/或，在同等腐蚀环境下，所述易腐蚀涂层的腐蚀速率大于带耐腐涂层的芯纤维的腐蚀速率。
  4. 根据权利要求1所述的一种腐蚀驱动智能纤维；其特征在于：所述芯纤维选自无机纤维、聚合物纤维中的至少一种；所述芯纤维的当量直径小于等于20mm，优选为小于等于5mm。
  5. 根据权利要求1所述的一种腐蚀驱动智能纤维；其特征在于：所述耐腐涂层的材质选自铜、镍、铬、镉、银、金元素中的至少一种。
  6. 根据权利要求1所述的一种腐蚀驱动智能纤维；其特征在于：所述腐蚀驱动智能纤维的截面形状选自圆形、多边形、异形截面中的一种，所述异形截面包括槽形、十字形、井字形、三叶形、梅花形、星形中的至少一种，
    所述腐蚀驱动智能纤维的表面可以是压痕或者带肋形状；
    所述腐蚀驱动智能纤维外形为平直形、压棱形、波形、弯钩形、大头形、双大头形、双尖形或集束型。
  7. 根据权利要求2所述的一种腐蚀驱动智能纤维；其特征在于：
    所述芯纤维或者包覆有耐腐涂层的芯纤维，其标准电极电位大于易被腐蚀涂层，或者其活泼性小于易被腐蚀涂层。
  8. 根据权利要求1-7任意一项所述的一种腐蚀驱动智能纤维；其特征在于：
    所述腐蚀驱动智能纤维包括易腐蚀涂层、芯纤维或者带耐腐涂层的芯纤维,芯纤维或者带耐腐涂层的芯纤维的侧面包覆有易腐蚀涂层；
    或
    所述腐蚀驱动智能纤维包括易腐蚀涂层、芯纤维或者带耐腐涂层的芯纤维,芯纤维或者带耐腐涂层的芯纤维除锚固端之外的侧面包覆有易腐蚀涂层。
  9. 根据权利要求1-7任意一项所述的一种腐蚀驱动智能纤维；其特征在于：
    所述易腐蚀涂层为铁金属或者铁合金，芯纤维为钢纤维，耐腐涂层为铜金属或者铜合金。
  10. 一种如权利要求1-9任意一项所述腐蚀驱动智能纤维的制备方法：其特征在于：对芯纤维或带耐腐涂层的芯纤维施加拉力；然后在其表面设定区域制备易腐蚀涂层；卸除拉力，得到样品；所施加的拉力为芯纤维或带耐腐涂层的芯纤维承载力的10％至90％。
  11. 根据权利要求10所述的腐蚀驱动智能纤维的制备方法：其特征在于：在整个腐蚀驱动智能纤维中，为了使智能纤维对外界施加的预应力达到最大，其优化获取方法为：
    腐蚀驱动智能纤维的横截面面积一定的情况下，
    智能纤维的预应力存储的大小与芯纤维的体积分数V f密切相关，芯纤维存储的轴向力F为：
    Figure PCTCN2019091912-appb-100001
    当F达到最大时，智能纤维对外界的预应力作用将达到最大；
    求芯纤维的轴向力的最值，首先对F求导，得：
    Figure PCTCN2019091912-appb-100002
    即：
    Figure PCTCN2019091912-appb-100003
    令F′＝0，则：
    (E c-E f)V f 2-2E cV f+E c＝0(14)
    当E c＝E f时，得
    Figure PCTCN2019091912-appb-100004
    此时F可以取最值，即得到Fmax；
    当E c≠E f时，对于方程
    Figure PCTCN2019091912-appb-100005
    令
    Figure PCTCN2019091912-appb-100006
    由于E c＞0，E f＞0，则a＜0或者a＞1，那么有Δ＝4a 2-4a＞0，原方程有两个不同的实根，即：
    Figure PCTCN2019091912-appb-100007
    又由于0＜V f＜1，而当E c＜E f时，则
    Figure PCTCN2019091912-appb-100008
    当E c＞E f时，
    Figure PCTCN2019091912-appb-100009
    则实根
    Figure PCTCN2019091912-appb-100010
    不满足0＜V f＜1的条件，应该舍去；而当
    Figure PCTCN2019091912-appb-100011
    V f满足16式的条件，使F可以取最大值，即得到Fmax；
    其中，
    σ o为芯纤维的初始张拉应力值；
    Figure PCTCN2019091912-appb-100012
    为芯纤维存储的应力值；
    E c为易腐蚀涂层的弹性模量；
    E f为芯纤维的弹性模量；
    V c，V f分别为易腐蚀涂层和芯纤维的体积分数，V c+V f＝1；
    A f为芯纤维的截面面积；
    A为智能纤维的截面面积。
  12. 一种如权利要求1-9任意一项所述腐蚀驱动智能纤维的应用：其特征在于：包括将其用于混凝土或纤维增强树脂复合材料中；
    当将所述腐蚀驱动智能纤维用于混凝土时，所述腐蚀驱动智能纤维锚固于混凝土中；其腐蚀驱动条件为混凝土的使用环境。
  13. 根据权利要求1-9所述的一种腐蚀驱动智能纤维的应用；其特征在于：将所述腐蚀驱动智能纤维用于混凝土中时，其用量为0.01～20v％。
PCT/CN2019/091912 2018-11-14 2019-06-19 一种腐蚀驱动智能纤维及其制备方法和应用 WO2020098271A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2019284139A AU2019284139B2 (en) 2018-11-14 2019-06-19 Corrosion-driven intelligent fiber, preparation method and application thereof
JP2021525575A JP7029866B2 (ja) 2018-11-14 2019-06-19 腐食駆動型スマート繊維及びその調製方法及び応用

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201811354857.8 2018-11-14
CN201811354857.8A CN111189768B (zh) 2018-11-14 2018-11-14 一种腐蚀驱动智能纤维及其制备方法和应用

Publications (1)

Publication Number Publication Date
WO2020098271A1 true WO2020098271A1 (zh) 2020-05-22

Family

ID=70705795

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/091912 WO2020098271A1 (zh) 2018-11-14 2019-06-19 一种腐蚀驱动智能纤维及其制备方法和应用

Country Status (4)

Country Link
JP (1) JP7029866B2 (zh)
CN (1) CN111189768B (zh)
AU (1) AU2019284139B2 (zh)
WO (1) WO2020098271A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114440171A (zh) * 2022-02-16 2022-05-06 中山市乐熠智能电器有限公司 一种便于清洗的吸顶灯

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114804788B (zh) * 2022-06-29 2022-09-16 中冶建筑研究总院有限公司 珊瑚-水泥基复合材料、制备方法、使用方法及其应用

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102674873A (zh) * 2012-05-24 2012-09-19 中南大学 一种预存应力筋增强复合材料及其制造方法
CN103046693A (zh) * 2011-11-28 2013-04-17 王子国 复合结构预存应力筋及其制造方法
CN103332945A (zh) * 2013-06-17 2013-10-02 中南大学 一种无裂纹涂层纤维的制备方法
CN104797764A (zh) * 2012-09-17 2015-07-22 Cpc公司 用于制造预应力混凝土部件的加强件、混凝土部件和制造方法
WO2017220408A1 (de) * 2016-06-22 2017-12-28 Lenz Tankred Verfahren und eine vorrichtung zur herstellung von betonbauteilen

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59190251A (ja) * 1983-04-11 1984-10-29 住友電気工業株式会社 繊維補強コンクリ−ト
JPH03126649A (ja) * 1989-10-09 1991-05-29 Nkk Corp 全方位プレストレストコンクリート
US5561173A (en) * 1990-06-19 1996-10-01 Carolyn M. Dry Self-repairing, reinforced matrix materials
FR2673223A1 (fr) * 1991-02-27 1992-08-28 Cogema Beton et son procede de mise en precontrainte, conteneur fabrique avec ce beton.
JPH07525U (ja) * 1992-06-15 1995-01-06 泰文 古屋 複合機能材料製造プロセス
JP4151053B2 (ja) * 2003-04-16 2008-09-17 株式会社竹中工務店 高強度高靭性セメント系材料の製造方法
US9533469B2 (en) * 2008-12-23 2017-01-03 Syracuse University Self-healing product
CN102140796B (zh) * 2010-12-24 2013-01-30 大连理工大学 一种纤维增强塑料智能锚杆
US9428647B2 (en) * 2011-05-06 2016-08-30 Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College Self-healing composite of thermoset polymer and programmed super contraction fibers
CN102900200B (zh) * 2012-10-09 2015-02-04 东南大学 一种智能frp-混凝土复合结构及其制造方法
CN102992673B (zh) * 2012-12-11 2015-01-14 同济大学 一种地下结构混凝土化学微胶囊抗氯盐腐蚀系统

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103046693A (zh) * 2011-11-28 2013-04-17 王子国 复合结构预存应力筋及其制造方法
CN102674873A (zh) * 2012-05-24 2012-09-19 中南大学 一种预存应力筋增强复合材料及其制造方法
CN104797764A (zh) * 2012-09-17 2015-07-22 Cpc公司 用于制造预应力混凝土部件的加强件、混凝土部件和制造方法
CN103332945A (zh) * 2013-06-17 2013-10-02 中南大学 一种无裂纹涂层纤维的制备方法
WO2017220408A1 (de) * 2016-06-22 2017-12-28 Lenz Tankred Verfahren und eine vorrichtung zur herstellung von betonbauteilen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114440171A (zh) * 2022-02-16 2022-05-06 中山市乐熠智能电器有限公司 一种便于清洗的吸顶灯
CN114440171B (zh) * 2022-02-16 2024-02-13 中山市乐熠智能电器有限公司 一种便于清洗的吸顶灯

Also Published As

Publication number Publication date
AU2019284139A1 (en) 2020-05-28
JP2022502339A (ja) 2022-01-11
CN111189768A (zh) 2020-05-22
CN111189768B (zh) 2023-03-10
JP7029866B2 (ja) 2022-03-04
AU2019284139B2 (en) 2020-07-09

Similar Documents

Publication Publication Date Title
US11459756B2 (en) Corrosion-induced shape memory fiber, preparation method and application thereof
Ferrara et al. On the use of crystalline admixtures in cement based construction materials: from porosity reducers to promoters of self healing
Wei et al. Tensile behaviour of carbon fabric reinforced cementitious matrix composites as both strengthening and anode materials
Green et al. FRP confined concrete columns: Behaviour under extreme conditions
Zheng et al. Experimental investigation of corrosion-damaged RC beams strengthened in flexure with FRP grid-reinforced ECC matrix composites
WO2020098271A1 (zh) 一种腐蚀驱动智能纤维及其制备方法和应用
Schlangen et al. Self-healing processes in concrete
CN109811879A (zh) 用于自修复混凝土的双层管状修复液承载系统
CN201043326Y (zh) 复合式纤维中空注浆锚杆
Zabanoot Review of autogenous and autonomous self-healing concrete technologies for marine environments
CN106703280A (zh) 一种纤维复合胶板及其制备方法
CN103011741B (zh) 一种钢筋混凝土结构的防锈修补方法
CN201043327Y (zh) 复合式纤维钢锚杆
CN104234245A (zh) 裂缝自愈合免拆保温系统及其制备方法
CN202324350U (zh) 一种带有防护涂层的钢筋
CN103321218B (zh) 预应力离心耐腐蚀空心方桩
Tekle et al. Bond properties of glass fibre reinforced polymer bars with fly-ash based geopolymer concrete
CN203049919U (zh) 环氧涂层钢绞线锚固结构
CN203373739U (zh) 预应力离心耐腐蚀空心方桩
Nuernberger Reasons and prevention of corrosion-induced failures of prestressing steel in concrete
Surahyo et al. Corrosion of Embedded Metals in Concrete
Nguyen et al. Dual function carbon fibre strengthening and cathodic protection anode for reinforced concrete structures
Zhang et al. Prospect analysis of the application of BFRP bar to bridges
CN103435282B (zh) 具有良好耐久性能的复合磷铝酸盐粘结剂及其粘结方法
CN218374708U (zh) 一种具有高强度的混凝土梁

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2019284139

Country of ref document: AU

Date of ref document: 20190619

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19883840

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021525575

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19883840

Country of ref document: EP

Kind code of ref document: A1