A steel fiber for concrete toughening

Abstract

The invention relates to a steel fiber for concrete toughening. The two ends are bent three times in different directions to effectively improve the action range of the bent part. At the same time, with the setting of a spiral toughening sleeve, the bonding force between the steel fiber and concrete can be greatly improved when used, and the internal stress of the concrete can be assisted to be released, so that the toughening effect on the concrete is better. At the same time, with the setting of a booster patch, a limiting interlayer can be formed between each circle of the spiral toughening sleeve, which effectively limits the spiral toughening sleeve, making it difficult to deform greatly in the lateral direction, and effectively improving its stability. At the same time, a certain gap is formed between the spiral toughening sleeve and the steel fiber body, so that when mixed with concrete slurry laterally, the steel fiber body, the spiral toughening sleeve and the concrete slurry can be sandwiched and embedded with each other. Compared with the direct contact between the steel fiber body and the concrete slurry, the bonding strength and stability are greatly improved, so that the toughening effect on the concrete is better.

Description

Technical Field

[0001] The present invention relates to a steel fiber, in particular to a steel fiber used for concrete toughening and applied in the technical field of steel fibers. Background Art

[0002] Steel fiber concrete is a new type of multiphase composite material formed by adding randomly distributed short steel fibers to ordinary concrete. These randomly distributed steel fibers can effectively hinder the expansion of micro cracks in concrete and the formation of macro cracks, significantly improving the tensile, bending, impact and fatigue resistance of concrete, and have good ductility.

[0003] In order to improve the sliding resistance with concrete and enhance the bonding strength, existing steel fibers are generally bent. However, this simple bending method has only a poor effect on improving stability, especially since the steel fibers are small and the local bending volume is even smaller, so its role is limited, resulting in insufficient bonding stability with concrete.

[0004] Therefore, there is an urgent need to provide a steel fiber with stronger bonding strength with concrete to achieve a better toughening effect on concrete. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the steel fiber is small in volume, and the local bulging and bending play a limited role, resulting in insufficient bonding stability between the steel fiber and the concrete.

[0006] In order to solve the above problems, the present invention provides a steel fiber for concrete toughening, comprising a steel fiber body and a spiral toughening sleeve sleeved outside the steel fiber body, wherein the steel fiber body comprises a long flat section, two curved arc limiting sections respectively fixedly connected to the left and right ends of the long flat section, two short flat sections respectively fixedly connected to the two curved arc limiting sections at one end away from each other, and an outer curved arc section fixedly connected to the end of the short flat section;

[0007] The spiral toughening sleeve includes a straight section located in the middle, two spiral sections fixedly connected to the left and right ends of the straight section, and two limiting rings respectively fixedly connected to the ends of the spiral sections;

[0008] The production process of steel fiber includes the following steps:

[0009] S1. Firstly, the steel raw material is subjected to wire drawing through a wire drawing die to obtain a steel bar, and then a plurality of steel bars are subjected to glue coating and drawing, and then the steel bars are cut according to the target length size of the steel fiber to obtain a steel sheet, wherein the glue used in the glue coating and drawing is a water-soluble glue;

[0010] S2. Bend the two ends of the steel sheet three times in sequence along the direction away from the middle of the steel sheet, and the bending directions of the two ends are opposite to each other, forming a central symmetry;

[0011] S3, soaking the steel sheet after the bending process in pure water to dissolve the water-soluble glue, and then washing and drying to obtain the steel fiber body;

[0012] S4. Wind a spiral toughening sleeve around the steel fiber body. First, wind a limiting ring around the steel wire at the first bend of the steel fiber body. Then, spirally coil the steel wire in the direction toward the middle of the long flat section. When it is about to reach the middle of the long flat section, stop coiling to make the steel wire directly straight. Then, reach the other side of the long flat section and perform reverse spiral coiling of the steel wire. Finally, wind a limiting ring around the other first bend again. Then, cut the steel wire to complete the winding of the spiral toughening sleeve.

[0013] In the above-mentioned steel fiber for concrete toughening, the two ends of the steel fiber body are bent three times respectively, and the directions of the two adjacent bends are opposite. Through multiple bending, the effective range of the bent part is effectively improved. At the same time, with the setting of the spiral toughening sleeve, when used, the bonding force between the steel fiber and the concrete can be greatly improved, and under its spiral setting, it can also play a role in assisting the release of the internal stress of the concrete, so that the toughening effect of the concrete is better.

[0014] As a further improvement of the present application, in the three bending operations of step S2, the turning angle of the arc limiting section formed by the first bending is 90-120°, the center line of the short flat section formed by the second bending is tangent to the center line of the arc limiting section, and the turning angle of the outer arc section formed by the third bending is 90-120°.

[0015] As a further improvement of the present application, the cross-section of the steel fiber body is an oblong, the two ends of the oblong are semicircles with the same radius, the middle is a straight line connecting the corresponding ends of the two semicircles, and the length of the straight line is not more than 2 times the diameter of the semicircle.

[0016] As another improvement of the present application, in step S4, the steel fiber body is pretreated with bilateral patches before the spiral toughening sleeve is wound. The pretreatment is specifically as follows: the power-assisting patches are magnetically attached to the middle of the two straight surfaces of the steel fiber body.

[0017] As another improvement supplement to the present application, when winding the spiral toughening sleeve, the steel wire is controlled to collide with the two semicircular ends of the steel fiber body, and at the same time, the steel wire is controlled not to contact the two flat surface ends of the steel fiber body. After the winding of the spiral toughening sleeve is completed, post-processing of the bilateral patch operation is performed.

[0018] As another improved supplement to the present application, the specific steps for post-processing of the double-sided patch are as follows: first, an external magnetic field is applied to one side of one of the straight end faces of the steel fiber body, the outer end of the adsorption-assisted patch is moved to the side away from the steel fiber body and a plurality of bulges are formed under the action of the spiral toughening sleeve, and the plurality of bulges are spaced apart from the ring layer of the spiral toughening sleeve, and then cement slurry is injected into the assisting patch, and after curing, the outward bulges of the assisting patch are shaped, and finally the above operation is repeated for the assisting patch on the other side to complete the post-processing operation of the double-sided patch of the steel fiber.

[0019] As another improved supplement of the present application, the power-assisting patch includes a filling layer, a magnetic strip fixedly connected to one end of the filling layer close to the steel fiber body, and a plurality of evenly distributed guide plates fixedly connected to the inside of the filling layer, the guide plates correspond to the middle of the magnetic strip, the filling layer is a hollow elastic structure, and the guide plates are located on the inner wall of the filling layer away from the magnetic strip.

[0020] As another improved supplement of the present application, the magnetic strip includes an inner isolation magnetic sheet fixedly connected to the filling layer and an outer magnetic sheet fixedly connected to the end of the inner isolation magnetic sheet away from the filling layer. The outer magnetic sheet and the guide sheet are both made of magnetic materials, and the inner isolation magnetic sheet is made of non-magnetic material.

[0021] As another improvement supplement of the present application, the width of the power-assisting patch before post-processing is not less than 2 / 3 of the width of the flat surface of the steel fiber body, the width of the magnetic strip is smaller than the width of the filling layer, the external magnetic field generates a magnetic attraction on the guide plate, and the distribution width of the external magnetic field is greater than the span of the guide plate and smaller than the width of the magnetic strip.

[0022] In summary, by bending three times in different directions at both ends, the effective range of the bending part is effectively increased. At the same time, with the setting of the spiral toughening sleeve, when used, the bonding force between the steel fiber and the concrete can be greatly improved, and it can also play a role in assisting the release of internal stress of the concrete, so that the toughening effect of the concrete is better; at the same time, with the setting of the assist patch, a limiting interlayer can be formed between each circle of the spiral toughening sleeve, which effectively limits the spiral toughening sleeve, making it less likely to undergo large deformation in the lateral direction, effectively improving its stability, and at the same time forming a certain gap between the spiral toughening sleeve and the steel fiber body, so that when subsequently mixed with the concrete slurry, the steel fiber body, the spiral toughening sleeve, and the concrete slurry can be sandwiched and embedded with each other, compared with the direct contact between the steel fiber body and the concrete slurry, the bonding strength and stability are greatly improved, so that the toughening effect of the concrete is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a three-dimensional diagram of the steel fiber according to the first embodiment of the present application;

[0024] Figure 2 This is an exploded view of the steel fiber of the first embodiment of the present application;

[0025] Figure 3 This is a front view of the steel fiber body according to the first embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the three-fold bending process of the steel fiber body of the first embodiment of the present application;

[0027] Figure 5 This is a partial schematic diagram of the second embodiment of the present application when the spiral toughening sleeve is wound after the pretreatment of the bilateral patch;

[0028] Figure 6 This is a schematic diagram of a radial cross section of a steel fiber body after pretreatment with a bilateral patch according to the second embodiment of the present application;

[0029] Figure 7 This is a schematic diagram of a radial cross section of a steel fiber body after post-processing with a bilateral patch according to the second embodiment of the present application;

[0030] Figure 8 This is a schematic diagram of the post-processing process of the bilateral patch according to the second embodiment of the present application.

[0031] Description of the numbers in the figure:

[0032] 1 steel fiber body, 11 long flat section, 12 curved arc limiting section, 13 short flat section, 14 outer curved arc section, 2 spiral toughening sleeve, 21 straight section, 22 spiral section, 12 limiting ring, 3 power assist patch, 31 filling layer, 321 outer magnetic sheet, 322 inner magnetic isolation sheet, 323 guide sheet. DETAILED DESCRIPTION

[0033] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0034] The first implementation method:

[0035] Figure 1-2 A steel fiber for concrete toughening is shown, comprising a steel fiber body 1 and a spiral toughening sleeve 2 sleeved outside the steel fiber body 1, wherein the steel fiber body 1 comprises a long flat section 11, two curved arc limiting sections 12 respectively fixedly connected to the left and right ends of the long flat section 11, two short flat sections 13 respectively fixedly connected to the ends of the two curved arc limiting sections 12 away from each other, and an outer curved arc section 14 fixedly connected to the end of the short flat section 13;

[0036] The spiral toughening sleeve 2 includes a straight section 21 located in the middle, two spiral sections 22 fixedly connected to the left and right ends of the straight section 21, and two limiting rings 23 respectively fixedly connected to the ends of the spiral sections 22;

[0037] The production process of steel fiber includes the following steps:

[0038] S1. Firstly, the steel raw material is subjected to wire drawing through a wire drawing die to obtain a steel bar, and then a plurality of steel bars are subjected to glue coating and drawing, and then the steel bars are cut according to the target length size of the steel fiber to obtain a steel sheet, wherein the glue used in the glue coating and drawing is a water-soluble glue;

[0039] S2, such as Figure 4 , along the direction away from the middle of the steel sheet, the two ends of the steel sheet are bent three times in sequence, and the bending directions of the two ends are opposite, forming a central symmetry;

[0040] S3, soaking the steel sheet after the bending process in pure water to dissolve the water-soluble glue, and then washing and drying to obtain the steel fiber body 1;

[0041] S4. Wind the spiral toughening sleeve 2 around the steel fiber body 1. First, wind a limiting ring around the steel wire at the first bend of the steel fiber body 1. Then, spirally coil the steel wire in the direction toward the middle of the long flat section 11. When it is about to reach the middle of the long flat section 11, stop coiling to make the steel wire directly straight. Then, reach the other side of the long flat section 11 and perform the reverse spiral coiling operation. Finally, wind a limiting ring around the other first bend again, i.e., a limiting ring 23. Then, cut the steel wire to complete the winding of the spiral toughening sleeve 2.

[0042] like Figure 3 In the three bending operations of step S2, the angle at the turning point of the arc limiting section 12 formed by the first bending is 60-90°, making the bending angle an acute angle. When the spiral toughening sleeve 2 is wound, the limiting ring 23 has a better limiting effect when it is set at this position, making the spiral toughening sleeve 2 relatively stable and not prone to lateral movement. The center line of the short flat section 13 formed by the second bending is tangent to the center line of the arc limiting section 12. The turning point of the outer curved arc section 14 formed by the third bending is 90-120°. The directions of the three bendings corresponding to the two ends of the steel fiber body 1 are opposite, so that the two ends have opposite overall directions, so that it can effectively grasp the concrete when it is in the concrete, and then it is not easy to have relative displacement with the concrete, so that the toughening effect on the concrete is better.

[0043] In the above-mentioned steel fiber for concrete toughening, by bending three times at both ends of the steel fiber body 1, and the directions of the two adjacent bendings are opposite, the range of action of the bent part is effectively improved through multiple bending. At the same time, with the setting of the spiral toughening sleeve 2, when used, the bonding force between the steel fiber and the concrete can be greatly improved, and under its spiral setting, it can also play a role in assisting the release of the internal stress of the concrete, so that the toughening effect of the concrete is better.

[0044] The second implementation method:

[0045] Based on the first embodiment, this embodiment adds pre-processing and post-processing of the double-sided sticker, and the rest is consistent with the first embodiment.

[0046] Figure 5-Figure 6 It is shown that the cross-section of the steel fiber body 1 is an oblong, the two ends of the oblong are semicircles with the same radius, the middle is a straight line connecting the corresponding ends of the two semicircles, and the length of the straight line is not more than 2 times the diameter of the semicircle. In step S4, the steel fiber body 1 is pretreated with bilateral patches before winding the spiral toughening sleeve 2. The pretreatment is specifically as follows: the power-assisting patches 3 are magnetically attached to the middle of the two straight surfaces of the steel fiber body 1.

[0047] like Figure 8 The power-assist patch 3 includes a filling layer 31, a magnetic strip fixedly connected to one end of the filling layer 31 close to the steel fiber body 1, and a plurality of uniformly distributed guide sheets 323 fixedly connected to the inside of the filling layer 31, wherein the guide sheet 323 corresponds to the middle of the magnetic strip, the filling layer 31 is a hollow elastic structure, and the guide sheet 323 is located on the inner wall of the filling layer 31 away from the magnetic strip, the magnetic strip includes an inner magnetic isolation sheet 322 fixedly connected to the filling layer 31, and an outer magnetic sheet 321 fixedly connected to one end of the inner magnetic isolation sheet 322 away from the filling layer 31, the outer magnetic sheet 321 and the guide sheet 323 are both made of magnetic materials, under the action of the outer magnetic sheet 321, the power-assist patch 3 can be adsorbed on the flat surface end of the steel fiber body 1 as a whole, the inner magnetic isolation sheet 322 is made of non-magnetic material, and can separate the outer magnetic sheet 321 and the guide sheet 323 which are both magnetic, so that when an external magnetic field is applied, it is not easy for the magnetism of the outer magnetic sheet 321 to cause unexpected changes in the power-assist patch 3.

[0048] When the spiral toughening sleeve 2 is wound, the steel wire is controlled to collide with the two semicircular ends of the steel fiber body 1, and the two flat ends of the steel fiber body 1 are controlled not to contact each other, so that there is a gap between the spiral toughening sleeve 2 and the flat surface of the steel fiber body 1, such as Figure 8 After the winding of the spiral toughening sleeve 2 is completed, the post-processing of the double-sided patch operation is carried out. The specific steps of the post-processing of the double-sided patch are: first, a magnetic field is applied to one side of one of the straight end faces of the steel fiber body 1, such as Figure 7The outer end of the adsorption-assisted patch 3 moves to the side away from the steel fiber body 1 and forms a plurality of bulges under the restriction of the spiral toughening sleeve 2, and the plurality of bulges are spaced apart from the circle layers of the spiral toughening sleeve 2, and then cement slurry is injected into the assisting patch 3. After curing, the outward bulges of the assisting patch 3 are shaped, and finally the above operation is repeated for the assisting patch 3 on the other side to complete the post-processing operation of the bilateral patch of the steel fiber. The plurality of bulges can effectively limit the stability between each circle of the spiral toughening sleeve 2, so that the two adjacent circle layers are not easily deformed to be close to or away from each other. When it is randomly distributed in the concrete, it is not easy to be deformed due to the instability between the circle layers. Cause deformation, and at the same time, multiple bulges are embedded between the spiral toughening sleeve 2 and the steel fiber body 1, and become one with the steel fiber body 1 and the spiral toughening sleeve 2. When the concrete is poured later, the contact area between the steel fiber and the concrete slurry is larger, and the bends, protrusions, etc. at the contact point are more densely distributed. At the same time, the concrete slurry will also penetrate into the gap between the spiral toughening sleeve 2 and the power-assisting patch 3. After solidification, there is no direct contact between the steel fiber and the concrete, but there is a phenomenon of interlacing and embracing. Compared with the steel fiber body 1 that exists alone, the bonding strength with the concrete is greatly improved, thereby significantly improving the toughening effect of the concrete as a whole.

[0049] It is worth noting that the width of the power-assisting patch 3 before post-processing is not less than 2 / 3 of the width of the flat surface of the steel fiber body 1, so that the width of the power-assisting patch 3 is not easy to be too small, and the outer bulge formed by it has a better limiting effect on the two adjacent ring layers of the spiral toughening sleeve 2, and the width of the magnetic stripe is smaller than the width of the filling layer 31, and the width of the magnetic stripe is not less than half of the width of the filling layer 31. Since the filling layer 31 is elastic, when the cement slurry is filled, the filling layer 31 can be expanded through deformation at the point where it is not in contact with the magnetic stripe, so that the radial length of the filling layer 31 bulging outward after being subjected to the magnetic force is larger, and the amplitude of the bulge is larger, which effectively improves the overall toughening effect of the steel fiber on the concrete, and the external magnetic field generates a magnetic attraction on the guide sheet 323, and the distribution width of the external magnetic field is greater than the span of the guide sheet 323 and less than the width of the magnetic stripe.

[0050] In summary, by bending the two ends of the steel fiber body 1 three times respectively, and the directions of the two adjacent bendings are opposite, the multiple bendings can effectively increase the range of action of the bent part, and at the same time, with the setting of the spiral toughening sleeve 2, when used, the bonding force between the steel fiber and the concrete can be greatly improved, and under the setting of the spiral toughening sleeve 2, its spiral setting can also play a role in assisting the release of the internal stress of the concrete, so that the toughening effect of the concrete is better; at the same time, with the pretreatment and post-treatment of the bilateral patch, a limiting interlayer can be formed between each circle of the spiral toughening sleeve 2, which effectively limits the spiral toughening sleeve 2, making it less likely to undergo large deformation in the lateral direction, effectively improving its stability, and at the same time, a certain gap is formed between the spiral toughening sleeve 2 and the steel fiber body 1, so that when mixed with the concrete slurry laterally, the steel fiber body 1, the spiral toughening sleeve 2, the auxiliary patch 3 and the concrete slurry can be sandwiched and embedded with each other, compared with the direct contact between the steel fiber body 1 and the concrete slurry, the bonding strength and stability are greatly improved, so that the toughening effect of the concrete is better.

[0051] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A steel fiber for concrete toughening, characterized in that: The invention comprises a steel fiber body (1) and a spiral toughening sleeve (2) sleeved outside the steel fiber body (1), wherein the steel fiber body (1) comprises a long flat section (11), two curved arc limiting sections (12) respectively fixedly connected to the left and right ends of the long flat section (11), two short flat sections (13) respectively fixedly connected to the ends of the two curved arc limiting sections (12) away from each other, and an outer curved arc section (14) fixedly connected to the ends of the short flat sections (13); The spiral toughening sleeve (2) comprises a straight section (21) located in the middle, two spiral sections (22) fixedly connected to the left and right ends of the straight section (21), and two limit rings (23) respectively fixedly connected to the ends of the spiral sections (22); The production process of the steel fiber comprises the following steps: S1. Firstly, the steel raw material is subjected to wire drawing through a wire drawing die to obtain a steel bar, and then a plurality of steel bars are subjected to glue coating and drawing, and then the steel bars are cut according to the target length size of the steel fiber to obtain a steel sheet, wherein the glue used in the glue coating and drawing is a water-soluble glue; S2. Bend the two ends of the steel sheet three times in sequence along the direction away from the middle of the steel sheet, and the bending directions of the two ends are opposite to each other, forming a central symmetry; S3, soaking the steel sheet after the bending process in pure water to dissolve the water-soluble glue, and then washing and drying to obtain a steel fiber body (1); S4, winding a spiral toughening sleeve (2) around the steel fiber body (1), first winding a limit ring around the steel wire at the first bend of the steel fiber body (1), then spirally winding the steel wire in a direction toward the middle of the long flat section (11), stopping the winding when it is about to reach the middle of the long flat section (11) so that the steel wire is directly in a straight line, and then reaching the other side of the long flat section (11) to perform a reverse spiral winding operation on the steel wire, and finally winding a limit ring around the other first bend again, and then cutting the steel wire to complete the winding of the spiral toughening sleeve (2); In the step S4, the steel fiber body (1) is pre-treated with a double-sided patch before the spiral toughening sleeve (2) is wound. The pre-treatment specifically comprises: magnetically attaching a power-assisting patch (3) to the middle of two straight surfaces of the steel fiber body (1); When the spiral toughening sleeve (2) is wound, the steel wire is controlled to collide with the two semicircular ends of the steel fiber body (1), and at the same time, the steel wire is controlled not to contact the two flat surface ends of the steel fiber body (1), and after the spiral toughening sleeve (2) is wound, a post-processing of a double-sided patch operation is performed; First, a magnetic field is applied to one side of one of the straight end faces of the steel fiber body (1), and the outer end of the adsorbing power-assisting patch (3) moves to the side away from the steel fiber body (1) and forms a plurality of bulges under the action of the spiral toughening sleeve (2), and the plurality of bulges and the ring layer of the spiral toughening sleeve (2) are spaced apart from each other. Then, cement slurry is injected into the power-assisting patch (3), and after curing, the outward bulges of the power-assisting patch (3) are fixed. Finally, the above operation is repeated for the power-assisting patch (3) on the other side, thereby completing the post-processing operation of the double-sided patch of the steel fiber.

2. The steel fiber for concrete toughening according to claim 1, characterized in that: In the three bending operations of step S2, the angle at the turning point of the arc limiting section (12) formed by the first bending is 60-90°, the center line of the short flat section (13) formed by the second bending is tangent to the center line of the arc limiting section (12), and the angle at the turning point of the outer bending arc section (14) formed by the third bending is 90-120°.

3. The steel fiber for concrete toughening according to claim 1, characterized in that: The cross section of the steel fiber body (1) is an oblong, the two ends of the oblong are semicircles with the same radius, the middle is a straight line connecting the corresponding ends of the two semicircles, and the length of the straight line is not greater than twice the diameter of the semicircle.

4. The steel fiber for concrete toughening according to claim 1, characterized in that: The power-assisting patch (3) comprises a filling layer (31), a magnetic strip fixedly connected to one end of the filling layer (31) close to the steel fiber body (1), and a plurality of uniformly distributed guide pieces (323) fixedly connected to the inside of the filling layer (31), wherein the guide pieces (323) correspond to the middle of the magnetic strip, the filling layer (31) is a hollow elastic structure, and the guide pieces (323) are located on the inner wall of the filling layer (31) away from the magnetic strip.

5. The steel fiber for concrete toughening according to claim 4, characterized in that: The magnetic strip comprises an inner magnetic isolation sheet (322) fixedly connected to the filling layer (31) and an outer magnetic sheet (321) fixedly connected to an end of the inner magnetic isolation sheet (322) away from the filling layer (31), the outer magnetic sheet (321) and the guide sheet (323) being both made of magnetic materials, and the inner magnetic isolation sheet (322) being made of non-magnetic material.

6. The steel fiber for concrete toughening according to claim 5, characterized in that: The width of the assist patch (3) before post-processing is not less than 2 / 3 of the width of the flat surface of the steel fiber body (1), the width of the magnetic strip is less than the width of the filling layer (31), the externally applied magnetic field generates a magnetic attraction force on the guide piece (323), and the distribution width of the externally applied magnetic field is greater than the span of the guide piece (323) and less than the width of the magnetic strip.

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