Concrete fiber and its application

Abstract

The present invention discloses a novel concrete fiber and its application, belonging to the technical field of concrete fillers. The concrete fiber of the present invention comprises fibers, capsules, and a cement-based permeable crystalline waterproof material. The key technical point of the present invention is to add capsules to the fibers and fill the capsules with the cement-based permeable crystalline waterproof material. When concrete is added with concrete fibers, it can achieve self-healing of microcracks in the concrete and inhibit the expansion of macrocracks in the concrete, thereby significantly improving the concrete's crack resistance, erosion resistance, impact resistance, anti-penetration, and durability. The present invention has a simple structure and is convenient and easy to use.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete fillers, in particular to a novel concrete fiber and application thereof. Background Art

[0002] Concrete is a highly brittle building material with high shrinkage, low tensile strength, and poor toughness. It is prone to cracking during service. Cracks degrade the concrete's mechanical properties and provide pathways for the intrusion of harmful substances, leading to a range of problems such as deep concrete erosion and steel corrosion, ultimately resulting in structural failure.

[0003] By incorporating fibers into concrete, they bond to the concrete matrix. When the concrete cracks, the fibers act as bridges between the cracks, thereby enhancing the concrete's toughness and strength. This method is currently widely adopted. However, the extent of this bridging effect is related to the crack width. When the crack width is small, the bridging effect is weak, making it difficult for the fibers to suppress the expansion of microcracks. Fibers only become effective after microcracks have developed into wider macrocracks. Therefore, fibers cannot effectively suppress crack growth in the early stages of their development.

[0004] Chinese patent CN108751869A discloses a permeable crystallization self-repairing concrete structure and its production method, comprising a concrete component uniformly provided with permeable crystallization material particles and sodium silicate repair agent particles, wherein the sodium silicate repair agent particles are in a microcapsule structure. The invention also provides a method for producing permeable crystallization self-repairing concrete. This invention can improve the mechanical properties and waterproofing and impermeability of concrete structures, and enable them to self-repair damage, thereby enhancing the safety, durability, and cost-effectiveness of concrete structures.

[0005] Cement-based penetrating crystalline waterproofing material is a self-healing material commonly used in concrete. It can be applied to the concrete surface or incorporated into concrete. When concrete cracks, the active chemicals contained in this material react with the water that seeps through the cracks to form water-insoluble crystals. The continuous deposition of crystals in the cracks can block the cracks and achieve self-repair of the concrete. However, this material can only heal microcracks with a small width (approximately 0.4mm or less), and its self-healing ability for macrocracks is significantly weakened or even ineffective.

[0006] In summary, the effectiveness of fiber and cement-based penetrating crystalline waterproofing materials for microcracks and macrocracks is almost mutually exclusive. Properly utilizing the applicable objects of both and researching a new type of concrete fiber has important practical value and broad market prospects. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, in a first aspect of the present invention, a concrete fiber for improving the crack resistance, erosion resistance, impact resistance, penetration resistance and durability of concrete is provided, comprising a fiber 1, a capsule chamber 2 and a cement-based penetrating crystalline waterproof material; the capsule chamber 2 comprises a capsule chamber shell 21 and a receiving cavity 22; the fiber 1 passes through the capsule chamber 2 and is fixedly connected to the capsule chamber shell 21, and the cement-based penetrating crystalline waterproof material is filled in the receiving cavity 22. Under the action of tension, the fiber 1 and the capsule chamber shell 21 are deformed at the same time, and the capsule chamber shell 21 ruptures before the fiber 1, releasing the cement-based penetrating crystalline waterproof material in the receiving cavity 22.

[0008] The present invention is incorporated into concrete to form a composite material with the concrete. Under the action of external load, due to the uneven stress distribution, micro cracks and macro cracks will be generated in the concrete at the same time. (1) When micro cracks are generated in the concrete, the capsule chamber will be deformed accordingly. If the brittle shell of the capsule chamber exceeds its tensile limit, the shell will rupture. At this time, the cement-based penetrating crystalline waterproof material in the capsule chamber is released, and the active chemical substances therein react with the water infiltrating into the cracks to generate crystals that are deposited in the micro cracks. Since the cement-based penetrating crystalline waterproof material can be continuously released from the capsule chamber, the active chemical substances can maintain a high concentration and the crystals can maintain a high deposition rate, thereby ensuring the self-healing efficiency of the micro cracks. When loaded again, the micro cracks that are repaired in time will no longer be the weak parts of the concrete. (2) When macro cracks are generated in the concrete, the capsule chamber will also be deformed, causing the capsule chamber shell to rupture. However, the cement-based penetrating crystalline waterproof material released in the capsule chamber is not enough to repair the macro cracks. However, at this time, the fibers can play a bridging role between the cracks, thereby limiting the expansion of the cracks and enhancing the toughness and strength of the concrete. In addition, although cement-based penetrating crystalline waterproof materials are unable to repair macro cracks, they still have the ability to repair micro cracks near the fibers. Therefore, they can strengthen the bonding between the fibers and the concrete matrix and reduce the possibility of fiber slippage, which is conducive to the bridging role of the fibers between cracks and further enhance the toughness and strength of the concrete.

[0009] In the present invention, under the condition that the shell of the capsule chamber breaks before the fibers, the shape of the capsule chamber is diverse, and a suitable shape can be selected according to the application requirements of the concrete. Among them, the ellipsoid is a particularly suitable and universally applicable shape. Preferably, the shape of the capsule chamber 2 is an ellipsoid.

[0010] The position where the fiber passes through the chamber will affect the timing of the chamber shell rupture. The tension required for the chamber to rupture at different positions is different. In order to improve the uniformity and controllability of concrete fibers, preferably, the fiber 1 passes through the chamber 2 axially and is fixedly connected to the chamber shell 21.

[0011] The cement-based penetrating crystallization waterproof material filled in the accommodating cavity can be of the type commonly used in the art. In order to facilitate the release of the material to achieve a better repair effect, preferably, the physical form of the cement-based penetrating crystallization waterproof material includes liquid or powdered solid.

[0012] The capsule chamber made of polymer can achieve a balance between storing cement-based permeable crystalline waterproof material and being broken by external force. Preferably, the material of the capsule chamber shell 21 includes one of polyvinyl alcohol (PVA), polyethylene (PE), and polypropylene (PP).

[0013] The bridging effect of the fibers on cracks can enhance the toughness and strength of concrete. Preferably, the fibers 1 include synthetic fibers or steel fibers.

[0014] Further preferably, the synthetic fiber includes one of polyvinyl alcohol (PVA) fiber, polyethylene (PE) fiber, and polypropylene (PP) fiber.

[0015] Further preferably, the steel fiber includes one of carbon steel fiber, low alloy steel fiber and stainless steel fiber.

[0016] Further preferably, the shape of the steel fiber includes a straight shape or a special shape, and the special shape includes one of an indentation shape, a wave shape, an end hook shape, a big head shape, and an irregular pitted shape.

[0017] Further preferably, the synthetic fiber includes one of monofilament fiber, split fiber, and coarse fiber.

[0018] In a second aspect of the present invention, there is provided a use of the concrete fiber according to the first aspect of the present invention, specifically a use of the concrete fiber as a concrete filling material in preparing concrete.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] The invention provides a concrete fiber which has a simple structure and can significantly improve the crack resistance, erosion resistance, impact resistance, penetration resistance and durability of concrete.

[0021] The present invention provides an application of concrete fiber, which is used as a filling material in concrete. It can enable the cement-based penetrating crystalline waterproof material to be continuously and concentratedly released at the micro-cracks of the concrete, thereby improving the effective conversion rate of the cement-based penetrating crystalline waterproof material, and can also limit the expansion of macro-cracks, thereby enhancing the toughness and strength of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional schematic diagram of concrete fiber;

[0023] Figure 2is a cross-sectional schematic diagram of concrete fiber;

[0024] In the figure, 1 is a fiber, 2 is a capsule chamber, 21 is a capsule chamber shell, and 22 is a receiving cavity. DETAILED DESCRIPTION

[0025] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0026] Example 1

[0027] like Figure 1 、 2 As shown, a concrete fiber is composed of fibers, ellipsoidal capsules and cement-based penetrating crystalline waterproof materials. The fibers are straight carbon steel fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproof materials are filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell will deform at the same time, and the capsule shell will rupture before the fibers, thereby releasing the cement-based penetrating crystalline waterproof materials in the receiving cavity.

[0028] The concrete fiber is used as a filling material in the preparation of concrete to repair microcracks and macrocracks. For microcracks, the cement-based penetrating crystalline waterproof material released from the capsule chamber can make the cracks self-healing. The cement-based penetrating crystalline waterproof material can be continuously released from the capsule chamber and concentrated on the microcracks, which can maintain a high concentration of active chemical substances and a high deposition rate of crystals, thereby ensuring the self-healing efficiency of microcracks. For macrocracks, the fiber can play an effective bridging role between the cracks, thereby limiting the expansion of the cracks and enhancing the toughness and strength of the concrete. The cement-based penetrating crystalline waterproof material can repair microcracks near the fiber, strengthen the bonding between the fiber and the concrete matrix, and reduce the possibility of fiber slippage, which is conducive to the bridging role of the fiber between the cracks and further enhancing the toughness and strength of the concrete.

[0029] Example 2

[0030] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are monofilament polyvinyl alcohol fibers. The capsules include a capsule shell made of polyethylene and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Powdered solid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0031] Example 3

[0032] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are indented low-alloy steel fibers. The capsules include a capsule shell made of polypropylene and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0033] Example 4

[0034] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are corrugated stainless steel fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule 2 axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0035] Example 5

[0036] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are membrane-split polyethylene fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0037] Example 6

[0038] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are coarse polypropylene fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0039] Example 7

[0040] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are hook-ended carbon steel fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell deform simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0041] Example 8

[0042] A concrete fiber is composed of fibers, ellipsoidal capsules, and cement-based penetrating crystalline waterproofing material. The fibers are large-headed carbon steel fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule 2 axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed simultaneously, and the capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity.

[0043] Example 9

[0044] A concrete fiber is composed of fibers, ellipsoidal capsules and cement-based penetrating crystalline waterproofing material. The fibers are irregularly pockmarked carbon steel fibers. The capsules include a capsule shell made of polyvinyl alcohol and a receiving cavity. The fibers pass through the capsule axially and are fixedly connected to the capsule shell. Liquid cement-based penetrating crystalline waterproofing material is filled in the receiving cavity. Under the action of tension, the fibers and the capsule shell are deformed at the same time. The capsule shell ruptures before the fibers, thereby releasing the cement-based penetrating crystalline waterproofing material in the receiving cavity 22.

[0045] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A concrete fiber, comprising a fiber (1), a capsule (2) and a cement-based permeable crystalline waterproof material, characterized in that: The capsule chamber (2) comprises a capsule chamber shell (21) and a receiving cavity (22); the fiber (1) passes through the capsule chamber (2) and is fixedly connected to the capsule chamber shell (21); the cement-based penetrating crystalline waterproof material is filled in the receiving cavity (22); under the action of tension, the fiber (1) and the capsule chamber shell (21) are deformed at the same time, and the capsule chamber shell (21) ruptures before the fiber (1), releasing the cement-based penetrating crystalline waterproof material in the receiving cavity (22); The capsule chamber (2) is shaped like an ellipsoid; the fiber (1) passes through the capsule chamber (2) along the axial direction and is fixedly connected to the capsule chamber shell (21); the material of the capsule chamber shell (21) includes one of polyvinyl alcohol, polyethylene, and polypropylene; and the fiber (1) includes synthetic fiber or steel fiber.

2. The concrete fiber according to claim 1, characterized in that: The synthetic fiber includes one of polyvinyl alcohol fiber, polyethylene fiber and polypropylene fiber.

3. The concrete fiber according to claim 1, characterized in that: The steel fiber includes one of carbon steel fiber, low alloy steel fiber and stainless steel fiber.

4. The concrete fiber according to claim 1, characterized in that: The shape of the steel fiber includes straight shape or special shape, and the special shape includes one of indentation shape, wave shape, end hook shape, big head shape and irregular pitted shape.

5. The concrete fiber according to claim 1, characterized in that: The synthetic fiber comprises one of monofilament fiber, split fiber and coarse fiber.

6. Use of the concrete fiber according to any one of claims 1 to 5, characterized in that: The application of concrete fiber as concrete filling material in the preparation of concrete.

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