3D printing concrete beam with embedded intelligent mortar rod

Abstract

The utility model provides a 3D printing concrete beam with an embedded intelligent mortar rod, which relates to the technical field of constructional engineering and comprises a 3D printing concrete beam, at least two reinforcing steel bars are embedded in the 3D printing concrete beam, and at least one intelligent mortar rod is further embedded between the two reinforcing steel bars in the 3D printing concrete beam. The shape, structure and size of the intelligent mortar rod are consistent with those of the steel bar; at least one electrode is fixed on the intelligent mortar rod, and an external wire is connected to the electrode so as to measure the resistance change rate of the intelligent mortar rod; the concrete crack monitoring device can effectively monitor the concrete crack at the reinforcing steel bar of the 3D printing concrete beam.

Description

Technical Field

[0001] The utility model relates to the technical field of construction engineering, and in particular to a 3D printed concrete beam with embedded intelligent mortar rods. Background Art

[0002] With the development of science and technology, in some buildings with special requirements for shape and structure, it is often necessary to "print" the concrete structure through a computer according to a pre-set design model by stacking layer by layer. This also makes 3D printed concrete beams successfully applied in a large number of actual projects. However, 3D printed concrete is prone to shrinkage cracks due to the use of a large amount of cement, which seriously affects the strength, so crack control is particularly important for 3D printed concrete. If the cracks are diagnosed and reinforced at an early stage, a large amount of later maintenance costs can be saved, the safety and service life of the structure can be improved, thereby reducing the environmental and economic and social costs caused by structural reconstruction, and reducing carbon emissions caused by the use of cement and other building materials due to structural reconstruction.

[0003] At present, the monitoring and measurement of crack width of 3D printed concrete mainly relies on attaching optical fiber sensors to concrete beams or using equipment such as crack width gauges. Although the above equipment can monitor cracks on the surface of 3D printed concrete, it cannot measure the width of concrete cracks at the position of steel bars inside 3D printed concrete. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a 3D printed concrete beam with embedded intelligent mortar rods, which can effectively monitor concrete cracks at the steel bars of the 3D printed concrete beam.

[0005] The utility model provides a 3D printed concrete beam with an embedded intelligent mortar rod, comprising a 3D printed concrete beam, wherein at least two steel bars are embedded in the 3D printed concrete beam, and at least one intelligent mortar rod is embedded between the two steel bars in the printed concrete beam, wherein the shape, structure and size of the intelligent mortar rod are consistent with those of the steel bars; at least one electrode is fixed on the intelligent mortar rod, and an external wire is connected to the electrode for measuring the resistance change rate of the intelligent mortar rod.

[0006] Compared with the prior art, the present application has the following advantages: the intelligent mortar rod is buried between two steel bars, so that when the concrete at the steel bars is subjected to stress and cracks are generated, the position of the intelligent mortar rod will also be subjected to the same stress and corresponding cracks will also be generated. By applying power to the electrodes, the resistance change rate of the intelligent mortar rod can be obtained to infer the concrete crack conditions at the steel bars. Since it is necessary to accurately obtain the concrete crack information at the steel bars, the shape, structure and size of the intelligent mortar rod must be consistent with the steel bars to avoid errors.

[0007] In a possible implementation, there are four electrodes, namely the first electrode, the second electrode, the third electrode, and the fourth electrode. The first electrode and the second electrode are arranged at intervals on one side in the length direction of the intelligent mortar bar and are spaced apart along the length direction of the intelligent mortar bar. The third electrode and the fourth electrode are arranged at intervals on the other side in the length direction of the intelligent mortar bar and are spaced apart along the length direction of the intelligent mortar bar.

[0008] Compared with the prior art, adopting the above technical solution facilitates measuring the resistance by the four-electrode resistance measurement method, with high accuracy and sensitivity, and there is no need to cause destructive contact with the 3D printed concrete beam, and power-on measurement can be directly carried out. On the other hand, the four-electrode resistance measurement method can resist interference current, and the principle is simple and easy to implement.

[0009] In a possible implementation, the first electrode, the second electrode, the third electrode, and the fourth electrode are all formed by bonding with conductive tape on the outer peripheral wall of the intelligent mortar bar.

[0010] Compared with the prior art, adopting the above technical solution can facilitate the formation of the first electrode, the second electrode, the third electrode, and the fourth electrode, and the construction is convenient.

[0011] In a possible implementation, both ends of the steel bar and the intelligent mortar bar are provided with bending parts for anchoring.

[0012] Compared with the prior art, adopting the above technical solution can stably fix the steel bar and the intelligent mortar bar in the 3D printed concrete beam, and it is not easy to generate deviation, resulting in deviation in crack measurement.

[0013] In a possible implementation, the intelligent mortar bar is made by mixing mortar, steel fibers, and nano carbon black.

[0014] Compared with the prior art, the steel fibers and nano carbon black adopting the above technical solution can effectively make the conductive performance of the intelligent mortar bar better, and the mortar can make the material of the intelligent mortar bar also match that of the 3D printed concrete beam, increasing the accuracy of the measured resistance change rate, and the steel fibers themselves can also enhance the stiffness. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the present invention;

[0016] Figure 2 It is a schematic diagram of the intelligent mortar bar of the present invention;

[0017] Description of the Reference Numerals:

[0018] 1 - 3D printed concrete beam, 2 - steel bar, 3 - intelligent mortar bar, 23 - bending part, 31 - electrode, 311 - first electrode, 312 - second electrode, 313 - third electrode, 314 - fourth electrode, Detailed implementation manners

[0019] First of all, those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adjust them as needed to adapt to specific application scenarios.

[0020] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0021] In the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0022] The embodiments of the present application disclose a 3D printed concrete beam with an embedded intelligent mortar bar, including a 3D printed concrete beam 1. At least two steel bars 2 are embedded in the 3D printed concrete beam 1. At least one intelligent mortar bar 3 is also embedded between the two steel bars 2 in the printed concrete beam 1. The shape, structure and size of the intelligent mortar bar 3 are the same as those of the steel bar 2. At least one electrode 31 is fixed on the intelligent mortar bar 3, and an external wire is electrically connected to the electrode 31 for measuring the resistance change rate of the intelligent mortar bar 3.

[0023] In this embodiment, as shown in the appendix Figure 1As shown, there are two steel bars 2 arranged in the 3D printed concrete beam 1. The number of steel bars 2 can be flexibly adjusted according to the volume of the 3D printed concrete beam 1. The intelligent mortar bar 3 is located between the two steel bars 2. In this way, when cracks occur in the concrete at the position of the steel bar 2 due to stress, the position of the intelligent mortar bar 3 will also be subjected to the same stress and corresponding cracks will also occur. It should be noted that the mortar mix ratio of the intelligent mortar bar 3 should be the same as that of the 3D printed concrete beam 1. In this way, when cracks occur in the concrete at the position of the steel bar 2 due to stress, the position of the intelligent mortar bar 3 will be subjected to the same stress and corresponding cracks will occur. Since the mortar of the intelligent mortar bar 3 itself has conductivity, it can be directly used as a conductor to connect the electrode 31. After energizing the electrode 31, the concrete crack condition at the position of the steel bar 2 can be inferred from the resistance change rate of the electrode 31 on the intelligent mortar bar 3. Since it is necessary to accurately obtain the concrete crack information at the position of the steel bar 2, the shape, structure and size of the intelligent mortar bar 3 need to be the same as those of the steel bar 2 to avoid errors. The principle of the relationship between the resistance change rate and the crack is that after the crack occurs, the crack will cause the change of the conduction path inside the concrete. When the crack grows rapidly, there will be an obvious inflection point in the change of the resistance change rate, which makes the crack have a significant impact on the concrete resistance change rate. Under the influence of the crack, by observing the resistance change rate curve, a specific change pattern will appear. For example, in the case of high-angle cracks, the resistance change rate curve may be serrated. Therefore, by measuring the resistance change rate of the intelligent mortar bar 3, the concrete crack condition at the position of the steel bar 2 of the 3D printed concrete beam 1 can be effectively monitored.

[0024] In some embodiments, there are four electrodes 31, namely the first electrode 311, the second electrode 312, the third electrode 313 and the fourth electrode 314. The first electrode 311 and the second electrode 312 are arranged at intervals on one side in the length direction of the intelligent mortar bar 3 and are arranged at intervals along the length direction of the intelligent mortar bar 3. The third electrode 313 and the fourth electrode 314 are arranged at intervals on the other side in the length direction of the intelligent mortar bar 3 and are arranged at intervals along the length direction of the intelligent mortar bar 3.

[0025] In this embodiment, the first electrode 311, the second electrode 312, the third electrode 313 and the fourth electrode 314 are convenient for measuring the resistance by the four-electrode resistance measurement method. Among them, the first electrode 311 and the fourth electrode 314 are arranged on the outer side of the intelligent mortar bar 3, and the second electrode 312 and the third electrode 313 are arranged on the inner side of the intelligent mortar bar 3. The four-electrode resistance measurement method belongs to common knowledge. For the sake of simplicity of description, it will not be elaborated in this application. The four-electrode resistance measurement method has high accuracy and sensitivity, and there is no need to have a destructive contact with the 3D printed concrete beam. The power-on measurement can be directly carried out on the first electrode 311, the second electrode 312, the third electrode 313 and the fourth electrode 314. On the other hand, the four-electrode resistance measurement method can resist interference current and has a simple principle and is easy to implement.

[0026] In some embodiments, the first electrode 311, the second electrode 312, the third electrode 313, and the fourth electrode 314 are all formed by bonding to the outer peripheral wall of the intelligent mortar bar 3 through conductive tapes. The conductive tapes facilitate the formation of the first electrode 311, the second electrode 312, the third electrode 313, and the fourth electrode 314, and the construction is convenient.

[0027] In some embodiments, both ends of the steel bar 2 and the intelligent mortar bar 3 are provided with bending portions 23 for anchoring. As shown in the attached Figure 1 figure, the bending portion 23 may be a horizontally arranged U-shaped structure, which can stably fix the steel bar 2 and the intelligent mortar bar 3 in the 3D printed concrete beam 1 and is not likely to generate deviation, resulting in deviation in crack measurement.

[0028] In some embodiments, the intelligent mortar bar 3 is made of a mixture of mortar, steel fibers, and nano-carbon black. The steel fibers and nano-carbon black can effectively improve the electrical conductivity of the intelligent mortar bar 3 and the measurement accuracy of the resistance change rate, and the steel fibers themselves can also enhance the stiffness; the mortar can make the material of the intelligent mortar bar 3 match that of the 3D printed concrete beam 1. The mortar ratio needs to be consistent with the actual mortar ratio of the 3D printed concrete beam. Those skilled in the art can flexibly adjust according to the actual situation. Among them, the length of the steel fibers is 35 mm, the dosage of the steel fibers is 40 kg / m 3 , and the dosage of nano-carbon black is 1.5 kg / m 3 .

[0029] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms "inner", "outer", etc., indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application.

[0030] In the description of the present application, the descriptions referring to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific examples", or "some examples" mean that the specific features, mechanisms, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0031] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A 3D printed concrete beam with embedded intelligent mortar rods, comprising a 3D printed concrete beam (1), wherein at least two steel bars (2) are embedded in the 3D printed concrete beam (1), characterized in that: At least one intelligent mortar rod (3) is buried between the two steel bars (2) in the printed concrete beam (1); the shape, structure and size of the intelligent mortar rod (3) are consistent with those of the steel bars (2); at least one electrode (31) is fixed on the intelligent mortar rod (3); an external wire is connected to the electrode (31) for measuring the resistance change rate of the intelligent mortar rod (3).

2. The 3D printed concrete beam with embedded intelligent mortar rods according to claim 1, characterized in that: There are four electrodes (31), namely a first electrode (311), a second electrode (312), a third electrode (313) and a fourth electrode (314); the first electrode (311) and the second electrode (312) are arranged on one side of the length direction of the intelligent mortar rod (3), and are arranged at intervals along the length direction of the intelligent mortar rod (3); the third electrode (313) and the fourth electrode (314) are arranged at intervals on the other side of the length direction of the intelligent mortar rod (3), and are arranged at intervals along the length direction of the intelligent mortar rod (3).

3. The 3D printed concrete beam with embedded intelligent mortar rods according to claim 2, characterized in that: The first electrode (311), the second electrode (312), the third electrode (313) and the fourth electrode (314) are all formed by bonding on the outer peripheral wall of the smart mortar rod (3) by means of conductive tape.

4. The 3D printed concrete beam with embedded intelligent mortar rods according to claim 1, 2 or 3, characterized in that: Both ends of the steel bar (2) and the intelligent mortar rod (3) are provided with bending portions (23) for anchoring.

5. The 3D printed concrete beam with embedded intelligent mortar rods according to claim 1, 2 or 3, characterized in that: The intelligent mortar rod (3) is made by mixing mortar, steel fibers and nano carbon black.

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