A crack making device and method based on self-repairing concrete

Abstract

The present invention provides a crack making device and method based on self-repairing concrete, the device includes a specimen mold and an embedded part, the embedded part includes a grafted starch polymer material and a nickel sheet, the grafted starch polymer material has the property of absorbing water and swelling, when making a self-repairing concrete specimen, the grafted starch polymer material is attached to the surface of a long nickel sheet and embedded in the surface layer of the self-repairing concrete specimen, after the specimen reaches the specified curing time, the grafted starch polymer material is destroyed and the long nickel sheet is taken out, leaving a prefabricated defect on the surface of the specimen, and the crack of the required width is prepared by changing the diameter of the steel needle. The shape of the embedded part can be changed as needed, the device is suitable for preparing various crack shapes and widths, the prepared crack is not a traditional smooth crack surface, but a natural crack adapted to the project, the crack prepared by the specimen is clear, and the embedded part does not affect the mechanical properties.

Description

Technical Field

[0001] The present invention relates to a crack making device and method, and in particular to a crack making device and method based on self-repairing concrete. Background Art

[0002] Cement concrete is one of the largest materials required for construction projects. Concrete is a very strong building material. If constructed correctly under appropriate conditions, concrete structures can easily last 50 to 100 years or even longer. However, in most cases, time, wind, rain, and changes in the earth's crust will begin to form cracks in the concrete. These cracks allow air, water, corrosive ions, etc. to enter the concrete and slowly corrode the steel bars. The steel bars play a reinforcing role in the concrete structure. When the steel bars are corroded to a certain extent, the structure will eventually collapse. At present, with the development of self-repairing concrete technology, there are already microcapsule self-repairing concrete, polymer self-repairing concrete, microbial self-repairing concrete, etc., but the self-repairing functions of different types of self-repairing concrete vary greatly, so it is necessary to make cracks of different sizes and shapes to measure their repair capabilities. There are many defects in the existing crack making technology, such as the crack surface is too smooth and does not conform to the actual situation; the width and shape of the crack cannot be controlled when the crack is made by impact; the mechanical properties of the sample may change after the impact. Summary of the invention

[0003] Purpose of the invention: The present invention aims to provide a crack making device and method based on self-repairing concrete that is convenient for controlling the shape and width of the cracks; another purpose of the present invention is to provide a method for making cracks based on the device.

[0004] Technical solution: The crack making device based on self-repairing concrete described in the present invention includes a specimen mold and an embedded part. The specimen mold is a cavity for forming self-repairing concrete. The embedded part includes a nickel sheet and a grafted starch polymer material attached to the surface of the nickel sheet. The embedded part can be removably embedded in the surface of the self-repairing concrete and is used for crack making of the specimen.

[0005] Furthermore, the size of the specimen mold is or The grafted starch polymer material in the embedded part is a grafted starch acrylonitrile copolymer or a highly absorbent resin; the grafted starch polymer material has the property of swelling upon absorbing water. When making the self-repairing concrete specimen, the grafted starch polymer material is attached to the surface of the long nickel sheet and embedded in the surface of the self-repairing concrete specimen. After the specimen reaches the prescribed curing time, the grafted starch polymer material is destroyed and the long nickel sheet is taken out, leaving a prefabricated defect on the surface of the specimen. The crack of the required width is prepared by changing the diameter of the steel needle.

[0006] Furthermore, the thickness of the long strip nickel sheet attachment is 0.1-0.5 mm, the length is 80-100 mm, the width is 1-2 mm, and the shape of the nickel strip can be changed as required.

[0007] Furthermore, the distance between the two ends of the long strip nickel sheet attachment and the edge of the test piece is 0 to 10 mm, and the depth of the embedded part needs to be less than 2 mm.

[0008] The crack making method based on self-repairing concrete is applied to any of the above-mentioned devices, and the making steps are as follows:

[0009] (1) attaching the grafted starch polymer material to the surface of the long nickel sheet, spraying water on it to make it expand and adhere to the long nickel sheet;

[0010] (2) Filling the specimen mold with self-repairing concrete and embedding the embedded parts therein;

[0011] (3) After the above pouring is completed, it is cured for a prescribed period of time;

[0012] (4) After the curing is completed, the grafted starch polymer material is destroyed and the embedded parts are removed, and defects are formed on the concrete surface for making cracks.

[0013] Furthermore, self-repairing concrete is poured into the mold, and embedded parts are inserted before the self-repairing concrete is cured.

[0014] Furthermore, the repair material used in the self-repairing concrete is a microbial-cooperative bimetallic mineral repair carrier or other microbial repair carrier.

[0015] Furthermore, when making the cracks in step (4), steel needles of different diameters are selected to make the designed cracks along the prefabricated defects.

[0016] Furthermore, the diameter of the steel needle is 0.5-1.0 mm.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The shape and width of the self-repairing concrete cracks manufactured based on the device and method are adjustable, and the cracks are clear; the shape of the surface defects of the specimen is changed by changing the shape of the long nickel sheet attachment in the embedded part, and the diameter of the steel needle can also be adjusted to change the shape and width of the cracks; (2) The device and mold used are simple to operate, and are common materials, which are easy to process. The embedded parts are very simple to embed and remove before and after molding, and the removal of the embedded parts will not affect any properties of the concrete. The grafted starch acrylonitrile copolymer or the super absorbent resin material is cheap; (3) The cracks manufactured by the method are not the smooth crack surfaces prepared by the traditional method, but natural cracks adapted to the project, and the cracks prepared by the specimen are clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the crack making device of the present invention;

[0019] Figure 2 It is a structural schematic diagram of embedded parts;

[0020] Figure 3 To prepare surface defect maps in self-healing concrete;

[0021] Figure 4 Schematic diagram of crack preparation in the defect area using a steel needle. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0023] The crack making device of the present invention is as follows Figure 1 As shown, Figure 1 The accompanying drawings are marked as follows: 1. embedded part; 2. specimen mold; 3. long nickel sheet attachment; 4. grafted starch polymer material; 5. defect; 6. steel needle; 7. crack.

[0024] The device includes a specimen mold 2 and an embedded part 1. The specimen mold 1 is a cavity for forming self-repairing concrete. The surface of the embedded part 1 is attached with grafted starch acrylamide. The embedded part 1 is removably embedded in the surface of the self-repairing concrete and is used for making cracks in the specimen. The embedded part is a long nickel sheet attachment 3. The nickel sheet has a thickness of 0.1 to 0.5 mm, a length of 80 to 100 mm, and a width of 1 to 2 mm. The two ends of the nickel sheet are 0 to 10 mm away from the edge of the specimen, and the embedded depth of the embedded part is less than 2 mm.

[0025] The method for making cracks based on the above device is as follows:

[0026] (1) attaching grafted starch acrylamide to the surface of a nickel sheet, spraying water on it to make it swell and attach to the long nickel sheet;

[0027] (2) Filling the specimen mold with self-repairing concrete and embedding the embedded parts therein;

[0028] (3) After the above pouring is completed, it is cured for a prescribed period of time;

[0029] (4) After the curing is completed, the grafted starch polymer material 4 is destroyed and the embedded part 1 is taken out, a defect 5 is formed on the concrete surface, and steel needles 6 of different diameters are selected to make the designed cracks 7 along the prefabricated defect. The diameter of the steel needle 6 is 0.5-1.0 mm.

Claims

1. A crack making device based on self-repairing concrete, characterized in that: It includes a specimen mold and an embedded part. The specimen mold is a cavity for forming self-repairing concrete. The embedded part includes a nickel sheet and a grafted starch polymer material attached to the surface of the nickel sheet. The embedded part can be removably embedded in the surface of the self-repairing concrete and is used for making cracks in the specimen.

2. The crack making device according to claim 1, characterized in that: The grafted starch polymer material is a grafted starch acrylonitrile copolymer.

3. The crack making device according to claim 1, characterized in that: The nickel sheet has a thickness of 0.1 to 0.5 mm, a length of 80 to 100 mm, and a width of 1 to 2 mm.

4. The crack making device according to claim 1, characterized in that: The distance between the two ends of the nickel sheet and the edge of the test piece is 0-10 mm, and the depth of the embedded part is less than 2 mm.

5. A crack making method based on the device according to any one of claims 1 to 4, characterized in that: Here are the steps: (1) attaching the grafted starch polymer material to the surface of the nickel sheet, spraying water on it to make it expand and adhere to the long nickel sheet; (2) Filling the specimen mold with self-repairing concrete and embedding the embedded parts therein; (3) After the above pouring is completed, it is cured for a prescribed period of time; (4) After the curing is completed, the grafted starch polymer material is destroyed and the embedded parts are removed, and defects are formed on the concrete surface for making cracks.

6. The crack making method according to claim 5, characterized in that: The repair material used in the self-repairing concrete is a microbial synergistic bimetallic mineral repair carrier or other microbial repair carrier.

7. The crack making method according to claim 5, characterized in that: When making the cracks in step (4), a steel needle is used to make the designed cracks along the pre-made defects.

8. The crack making method according to claim 7, characterized in that: The diameter of the steel needle is 0.5-1.0 mm.

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