A concrete strength detection method and device

Abstract

The present invention relates to a concrete strength detection method and device, and the detection method comprises: S1: zeroing. S2: pushing a probe into a concrete sample to be tested, and the probe stops when either the penetration resistance or the penetration depth of the probe reaches a preset value. S3: judging whether the corresponding test point is valid. S4: the control component calculates the concrete strength of the corresponding test point according to the ratio of the penetration resistance and the penetration depth when the probe stops. S5: collecting concrete strength data of a plurality of valid test points, and calculating the average value. When either the penetration resistance or the penetration depth of the probe reaches a preset value, the present invention obtains the concrete strength by the ratio of the penetration resistance and the penetration depth of the probe at that moment. This detection method can improve the strength detection range of concrete. The detection method of the present invention is suitable for concrete with a strength of 0.3-10Mpa.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete quality detection, and specifically relates to a concrete strength detection method and device. Background Art

[0002] In bridge and tunnel construction, concrete strength is an important indicator to measure construction quality and ensure construction safety. As the main support method for tunnel construction, the strength information of shotcrete is very critical. The penetration method is a commonly used method for concrete strength testing, which mainly includes the following two methods:

[0003] The first is the recommended test method Method A: Penetration needle in the international standard ISO 14488-2, which is a fixed-depth force measurement, that is, the probe is penetrated into the concrete 15mm deep by static penetration, the maximum penetration resistance is measured, and the corresponding equivalent strength is obtained. The penetration resistance of this method is large, and the corresponding strength measured when the manual advancement is 300N is less than 0.5MPa. Therefore, it is difficult to meet the convenient operation requirements when the measurement range is further increased, and the applicable strength measurement range is narrow.

[0004] The second method is the penetration method recommended by the current "JGJ / T372-2016 Technical Specification for the Application of Shotcrete". Specifically, the penetration meter is used to dynamically penetrate the probe into the hardened concrete, and the penetration depth of the probe is measured. According to the predetermined correlation between the penetration depth and the concrete strength, the compressive strength of the concrete is estimated. However, there are also some problems with this method. First, the penetration method uses dynamic penetration, and the dynamic load is significantly affected by damping. Secondly, the detection is easily affected by the surface condition of the concrete and the type of concrete aggregate. The penetration depth measurement is greatly affected by the surface flatness, and the measurement positioning benchmark has a large error. In addition, manual measurement is easy to penetrate when the age is small, and the requirements for operators are also high.

[0005] Therefore, the penetration method generally has the problem of a narrow scope of application, and it is necessary to provide a concrete strength detection device and method with a wider detection range. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In order to solve the problem of narrow application range of the penetration method for testing concrete strength in the prior art, the present invention provides a concrete strength testing method and device.

[0008] (II) Technical solution

[0009] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0010] A concrete strength detection method, wherein the concrete strength detection device used in the detection method comprises: a housing, a probe disposed at one end of the housing, a mechanical detection component connected to the probe, a displacement detection component disposed on the housing and outside the probe, and a control component disposed inside the housing;

[0011] The concrete strength testing method includes the following steps:

[0012] S1: Zero the concrete strength testing device;

[0013] S2: Push the measuring needle into the concrete sample to be tested. When any one of the penetration resistance and the penetration depth of the measuring needle detected by the mechanical detection component and the displacement detection component reaches a preset value, stop pushing the measuring needle and pull out the measuring needle;

[0014] S3: Determine whether the corresponding test point is valid when the probe stops advancing. If it is valid, proceed to step S4. If it is invalid, return to step S1 and continue to execute downward.

[0015] S4: The control component calculates the concrete strength of the corresponding test point according to the ratio of the penetration resistance and the penetration depth when the measuring needle stops advancing;

[0016] S5: Return to step S1 and continue to execute downward, collect concrete strength data of multiple effective test points, and calculate the average value to obtain the strength of the tested concrete sample.

[0017] In the concrete strength detection method as described above, preferably, a guide sleeve capable of moving relative to the measuring needle is provided on the outer side of the measuring needle;

[0018] In step S1, the relative positions of the measuring needle and the guide sleeve are adjusted, and then zeroing is performed.

[0019] In the above concrete strength detection method, preferably, the diameter of the measuring needle is 1-2 mm;

[0020] In step S2, the measuring needle is pushed into the concrete sample to be tested at a constant speed of 2-5 mm / s.

[0021] In the concrete strength detection method as described above, preferably, in step S2, the preset value of the penetration resistance is 300-400N, and the preset value of the penetration depth is 10-15mm.

[0022] In the concrete strength detection method as described above, preferably, in step S3, whether the corresponding test point is valid is judged based on whether cracks are generated at the test point. If cracks have already occurred around the test point during the test, it is invalid. If there are no cracks around the test point, or cracks are generated after the probe is pulled out, it is valid.

[0023] In the concrete strength detection method as described above, preferably, the concrete strength detection device further comprises an ultrasonic detection component arranged on the guide sleeve;

[0024] In step S4, the control component also calculates the concrete strength obtained by ultrasonic detection according to the detection signal fed back by the ultrasonic detection component, and records it as the reference strength;

[0025] In step S5, after collecting concrete strength data of 6-10 groups of valid test points, the average value of the concrete strength data is compared with the reference strength. If the relative error between the two is less than 15%, the strength test of the tested concrete sample at this age is completed; if the relative error between the two is greater than 15%, return to step S1 and continue to execute downward to obtain concrete strength data of more valid test points, recalculate the average value, and compare it with the reference strength again until the relative error between the two is less than 15%.

[0026] The present invention also provides a concrete strength detection device used in the above detection method, comprising a housing, a measuring needle, a mechanical detection component, a displacement detection component and a control component;

[0027] The measuring needle is arranged at one end of the housing;

[0028] The mechanical detection component is connected to the measuring needle and is used to detect the penetration resistance of the measuring needle into concrete;

[0029] The displacement detection assembly is arranged on the housing and outside the measuring needle, and is used to detect the penetration depth of the measuring needle into the concrete;

[0030] The control component is arranged inside the shell, and is used for receiving and converting the detection signals of the mechanical detection component and the displacement detection component, and processing the detection signals to obtain the strength of the concrete according to the ratio of the penetration resistance to the penetration depth.

[0031] The concrete strength detection device as described above preferably further comprises an ultrasonic detection component arranged at the front end of the housing, wherein the ultrasonic detection component is used to detect the reference strength of the concrete;

[0032] The control component is also used to receive and convert the detection signal of the ultrasonic detection component, and compare the strength of the concrete obtained through the detection signals of the mechanical detection component and the displacement detection component with the reference strength of the concrete detected by the ultrasonic detection component.

[0033] In the concrete strength detection device as described above, preferably, the diameter of the measuring needle is 1-2 mm.

[0034] In the concrete strength detection device as described above, preferably, a guide sleeve is provided on the outer side of the measuring needle, and the guide sleeve can move relative to the measuring needle;

[0035] The ultrasonic detection component is an ultrasonic sensor arranged on the guide sleeve.

[0036] In the concrete strength testing device as described above, preferably, the mechanical testing component is connected to the measuring needle through a connecting rod and a drill chuck, the measuring needle is connected to the connecting rod through the drill chuck, and the other end of the connecting rod is connected to the mechanical testing component;

[0037] The drill chuck is partially arranged inside the guide sleeve, the guide sleeve can move relative to the drill chuck, the drill chuck and the guide sleeve are clearance-matched, and the outer diameter of the drill chuck is smaller than the inner diameter of the guide sleeve.

[0038] In the concrete strength detection device as described above, preferably, the displacement detection assembly comprises a laser displacement sensor and a reflective sheet respectively arranged on the housing and the guide sleeve;

[0039] The mechanical detection component is a force sensor.

[0040] In the concrete strength detection device as described above, preferably, the control component includes a signal conversion module, a single-chip processing module and a storage module, and the signal conversion module is used to receive and convert the detection signals of the mechanical detection component, the displacement detection component and the ultrasonic detection component, and transmit the detection signals to the single-chip processing module;

[0041] The single-chip processing module is used to process the detection signal to obtain the strength of the concrete and the reference strength of the concrete; the single-chip processing module is also used to compare the strength of the concrete obtained by the detection signals of the mechanical detection component and the displacement detection component with the reference strength of the concrete obtained by the ultrasonic detection component;

[0042] The storage module is used to store the penetration resistance and penetration depth of the effective test points, and is also used to store the detection signal of the ultrasonic component processed by the single-chip processing module.

[0043] As described above, the concrete strength detection device is preferably provided with an indication component on the housing, wherein the indication component is an indicator light or a buzzer, and when any one of the penetration resistance and the penetration depth of the probe into the concrete reaches a preset value, the indication component gives an indication.

[0044] In the concrete strength detection device as described above, preferably, a display screen and a button are also provided on the housing, and the indicating component, the display screen and the button are all electrically connected to the control component;

[0045] A power supply component is also arranged inside the housing;

[0046] A handle is arranged at the other end of the shell.

[0047] (III) Beneficial effects

[0048] The beneficial effects of the present invention are:

[0049] When either the penetration resistance or the penetration depth of the probe reaches a preset value, the concrete strength is obtained by the ratio of the penetration resistance and the penetration depth of the probe at that moment. The detection method of the invention is applicable to concrete with a strength of 0.3-10Mpa, and effectively improves the strength detection range of concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the overall structure of the concrete strength detection device of the present invention;

[0051] Figure 2 It is a schematic diagram of the state of the concrete strength detection device in the present invention during use;

[0052] Figure 3 It is a working principle diagram of the concrete strength detection device in the present invention.

[0053] [Description of Reference Numerals]

[0054] 1: Probe; 2: Drill chuck; 3: Connecting rod; 4: Force sensor; 5: Laser displacement sensor; 6: Reflector; 7: Guide sleeve; 8: Ultrasonic sensor; 9: Control component; 10: Indicator component; 11: Display screen; 12: Button; 13: Power supply component; 14: Handle; 15: Concrete sample. DETAILED DESCRIPTION

[0055] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0056] Example 1

[0057] The present embodiment provides a concrete strength detection method. The concrete strength detection device used in the detection method includes: a housing, a probe 1 arranged at one end of the housing, a mechanical detection component connected to the probe 1, a displacement detection component arranged on the housing and outside the probe 2, and a control component 9 arranged inside the housing.

[0058] The concrete strength testing method includes the following steps:

[0059] S1: Zeroing the concrete strength detection device so that the penetration resistance of the probe into the concrete detected by the mechanical detection component and the penetration depth of the probe into the concrete detected by the displacement detection component are zero.

[0060] S2: gradually push the probe 1 into the concrete sample 15 to be tested. When either the penetration resistance of the probe into the concrete detected by the mechanical detection component or the penetration depth of the probe into the concrete detected by the displacement detection component reaches a preset value, stop pushing the probe and pull it out.

[0061] S3: Determine whether the corresponding test point is valid when the probe stops advancing. If the test point is determined to be valid, proceed to step S4. If the test point is determined to be invalid, return to step S1 and continue to execute downward.

[0062] S4: The control component 9 calculates the concrete strength of the corresponding test point according to the ratio of the penetration resistance to the penetration depth respectively detected by the mechanical detection component and the displacement detection component when the measuring needle 1 stops advancing.

[0063] S5: Return to step S1 and continue to execute downward, collect concrete strength data of multiple valid test points, and calculate the average value of the concrete strength data of multiple valid test points to obtain the strength of the tested concrete sample.

[0064] The prior art generally obtains the strength of concrete by calculating the corresponding relationship between the penetration resistance of the probe and the concrete strength, or by calculating the corresponding relationship between the penetration depth and the concrete strength. However, in this embodiment, when either the penetration resistance or the penetration depth of the probe reaches a preset value, the concrete strength is obtained by the ratio of the penetration resistance and the penetration depth of the probe at that moment. Such a strength detection method has not appeared in the prior art. In this embodiment, the concrete strength is obtained by the ratio of the penetration resistance and the penetration depth of the probe. This detection method is suitable for the strength detection of concrete with a strength of 0.3-10Mpa, which effectively improves the strength detection range of concrete.

[0065] A guide sleeve 7 capable of moving relative to the measuring needle is arranged outside the measuring needle 1 to protect the measuring needle 1, prevent the measuring needle 1 from bending and breaking, and ensure that the measuring needle 1 can be vertically inserted into the concrete sample 15. In step S1, a relatively flat concrete sample is selected for testing, and the guide sleeve is firstly placed lightly against the concrete sample to be tested, and then the relative position of the measuring needle and the guide sleeve is adjusted, and then zeroing is performed.

[0066] In this embodiment, the diameter of the probe 1 is 1-2mm, which is smaller than 3-3.5mm in the prior art. In this embodiment, the diameter of the probe 1 is 1-2mm, which can widen the penetration depth range of the probe into the concrete sample under the same penetration resistance. The ratio of penetration resistance and penetration depth has a corresponding relationship with strength. The wider the range of the ratio of penetration resistance and penetration depth, the wider the corresponding strength detection range. In this embodiment, the diameter of the probe 1 is limited to 1-2mm, which can further expand the ratio range of penetration resistance and penetration depth, and further improve the strength detection range of concrete. Specifically, when the diameter of the probe is 1-2mm, the detection method of this embodiment can be applied to the strength detection of concrete with a strength of 0.3-10Mpa. In addition, the force that the human body can apply to the probe is generally 300-400N. This embodiment uses a probe with a smaller diameter, and there is no need to use external equipment to apply the penetration force to the detection device. It can only rely on manual application, which is more convenient for the operation of concrete strength detection. Specifically, in step S2, the probe is uniformly pushed into the tested concrete sample 15 at a speed of 2-5 mm / s to avoid cracks at the test point as much as possible. In addition, in step S2, the preset value of the penetration resistance is 300-400 N, and the preset value of the penetration depth is 10-15 mm. In this embodiment, the preset penetration resistance range is 300-400 N, and the operator can apply it himself without the help of external equipment, making the detection process faster and more convenient.

[0067] While the measuring needle is advancing the tested concrete sample at a constant speed of 2-5mm / s, the displacement detection component and the mechanical detection component will perform real-time detection of the penetration depth and penetration resistance of the measuring needle into the concrete sample, and feed back the detection signals of the penetration depth and penetration resistance to the control component.

[0068] The concrete strength detection device also includes an indication component, which may be a display light or a buzzer. The indication component is electrically connected to the control component. When any one of the penetration resistance of the probe into the concrete received by the control component and the penetration depth of the probe into the concrete detected by the displacement detection component reaches a preset value, the indication light lights up or the buzzer sounds an alarm, and the operator can stop the advancement of the probe according to the indication.

[0069] In step S3, whether the corresponding test point is valid is determined based on whether cracks are generated at the test point, so as to ensure that the test point can feedback the strength of the concrete and ensure that the obtained concrete strength data is more reliable. Specifically, the judgment standard is whether cracks are generated at the test point during the penetration of the probe. If cracks have already occurred around the test point during the test, it is invalid. If there are no cracks around the test point, or cracks are generated after the probe is pulled out, it is valid. Cracks generated during the process of pulling out the probe after the test is completed do not affect the validity of the test, and the result is still valid.

[0070] Step 4 specifically includes determining the ratio of the penetration resistance to the penetration depth when the measuring needle stops advancing, inputting the ratio of the maximum penetration resistance to the corresponding penetration depth when the measuring needle stops advancing into a preset concrete strength prediction model, and performing strength prediction processing on the test value of the measuring point based on the concrete strength prediction model to obtain the concrete strength. The concrete strength prediction model is obtained by iteratively training the preset model to be trained based on a preset number of ratios of the penetration resistance to the penetration depth and the concrete strength.

[0071] The concrete strength detection device also includes an ultrasonic detection component 8 disposed on the guide sleeve 7. Accordingly, in step S4, the control component also calculates the concrete strength obtained by ultrasonic detection based on the detection signal fed back by the ultrasonic detection component, and records it as the reference strength. In step S5, collect 6-10 groups of concrete strength data of effective test points, compare the average value of the concrete strength data with the reference strength, and if the relative error between the two is less than 15%, complete the strength detection of the tested concrete sample 15 at this age. If the relative error between the two is greater than 15%, repeat steps S1-S4, obtain more concrete strength data of effective test points, recalculate the average value, and compare it with the reference strength again until the relative error between the two is less than 15%.

[0072] The type of concrete aggregate has a great influence on its strength test. For example, when the aggregate particles are large, the concrete strength data obtained by the probe penetrating the large aggregate particles cannot accurately reflect the real strength of the concrete. In addition, the penetration method tests the average data of the concrete strength of multiple test points, and the test strength obtained only represents the local concrete strength. Due to the accidental nature of the test, there is a certain error in the concrete strength obtained by the penetration method test.

[0073] The ultrasonic strength detection method is to test the wave velocity of ultrasonic waves penetrating concrete by setting an integrated transceiver ultrasonic sensor. The propagation speed of ultrasonic waves inside concrete is related to the elastic modulus and density of concrete, and the elastic modulus of concrete is also related to the concrete strength. Therefore, the compressive strength of concrete can be inferred based on the ultrasonic wave velocity. The corresponding concrete detection range of ultrasonic detection of concrete strength is wider than the corresponding concrete detection range of the penetration method. Therefore, this embodiment uses an ultrasonic detection component to detect concrete strength, and the detection result is used as a reference. Then, the average value of the concrete strength data obtained by the penetration method of this embodiment is compared, in order to make the two methods mutually corroborate. If the relative error of the detection results of the two methods is large, the penetration method of this embodiment can collect strength data of more test points, and then compare it with the reference strength again until the relative error of the detection results of the two methods is within a reasonable range, so as to improve the accuracy of the concrete strength detection method of this embodiment and reduce the error. In addition, in addition to being less than 15%, the relative error between the average value of concrete strength data and the reference strength can also be selected according to different working conditions, and can also be set to be less than 10%, less than 8%, or less than 5%.

[0074] In addition, in step S3, if the test point is determined to be valid, the penetration displacement, penetration resistance and sound wave information of the penetration process are stored through the storage module in the control component. If the test point is determined to be invalid, the data of the test process of this point is not stored.

[0075] During the calculation process of step S4, the probe is grabbed from the stored data to reach a preset penetration resistance or a preset penetration depth, and strength calculation is performed.

[0076] This embodiment pre-sets the penetration resistance and penetration depth. Specifically, when the penetration depth of the probe into the concrete reaches a pre-set value first, the corresponding concrete strength is low. In this case, the corresponding maximum penetration resistance when the pre-set penetration depth is reached is used as the basis for strength calculation, avoiding the defect that the penetration depth is difficult to measure manually due to the low concrete strength. When the penetration resistance of the probe into the concrete reaches a pre-set value first, the corresponding concrete strength is high. In this case, the corresponding maximum penetration depth when the pre-set penetration resistance is reached is used as the basis for calculating the concrete strength, which can further improve the detection range of concrete strength under the condition that the operator holds the detection device and the operation is portable. Therefore, the detection method of this embodiment can detect both high-strength and low-strength concrete, which improves the scope of application of the detection method.

[0077] Example 2

[0078] like Figure 1-3As shown, this embodiment provides a concrete strength detection device used in the detection method of Embodiment 1, including a housing, a measuring needle 1, a mechanical detection component, a displacement detection component and a control component 9.

[0079] The probe 1 is arranged at one end of the housing, and the mechanical detection component is connected to the probe 1, and its function is to detect the penetration resistance of the probe 1 into the concrete. The displacement detection components are arranged on the housing and on the outside of the probe 1, and their function is to detect the penetration depth of the probe 1 into the concrete. The control component 9 is arranged inside the housing, and its function is to receive and transform the detection signals of the mechanical detection component and the displacement detection component, and process the detection signals, and calculate the strength of the concrete according to the ratio of the penetration resistance to the penetration depth.

[0080] Due to the influence of aggregates and the randomness of the test, in order to further improve the accuracy of the penetration method for testing concrete, the end of the detection device facing the concrete sample when actually used is the front end. In this embodiment, an ultrasonic detection component is also provided at the front end of the housing to detect the concrete strength through the ultrasonic detection component to obtain the reference strength. The control component 9 can also receive and convert the detection signal of the ultrasonic detection component, and compare the strength of the concrete obtained through the detection signals of the mechanical detection component and the displacement detection component with the reference strength of the concrete obtained through the ultrasonic detection component, so that the two detection results can be mutually verified.

[0081] In this embodiment, a guide sleeve 7 is further provided on the outside of the measuring needle 1, and the guide sleeve 7 can move relative to the measuring needle 1. The guide sleeve 7 can ensure that the measuring needle 1 is always perpendicular to the concrete sample 15 during the process of penetrating the concrete sample 15, which is conducive to the accuracy of the test. At the same time, since the measuring needle itself is relatively thin and the pressure rod has poor stability, it is easy to bend and break when subjected to external force without a guide sleeve. The guide sleeve 7 provided on the outside of the measuring needle 1 can protect the measuring needle and prevent the measuring needle from bending, deformation and breakage.

[0082] Preferably, the diameter of the measuring needle 1 is 1-2mm, which is smaller than 3-3.5mm in the prior art. When the diameter of the measuring needle 1 is smaller, the penetration depth range of the measuring needle into the concrete sample can be widened under the same penetration resistance, so the ratio of the penetration resistance to the penetration depth can have a wider range, and the corresponding strength detection range is also wider. Specifically, when the diameter of the measuring needle is 1-2mm, the detection device of this embodiment can be used to detect concrete with a strength of 0.3-10Mpa. In addition, this embodiment uses a measuring needle with a smaller diameter, and there is no need to use external equipment to apply a penetration force to the detection device. The strength detection range of the concrete can be widened by manual application, which is more convenient for the operation of concrete strength detection.

[0083] Preferably, the mechanical detection assembly is connected to the probe 1 through the connecting rod 3 and the drill chuck 2, the probe 1 is connected to the connecting rod 3 through the drill chuck 2, and the other end of the connecting rod 3 is connected to the mechanical detection assembly. The drill chuck 2 is partially arranged inside the guide sleeve 7, the drill chuck 2 and the guide sleeve 7 are clearance-matched, the guide sleeve 7 can move relative to the drill chuck 2, the outer diameter of the drill chuck 2 is smaller than the inner diameter of the guide sleeve 7, and the guide sleeve 7 acts as a radial limit on the drill chuck 2 to ensure that the probe vertically penetrates the measured surface.

[0084] Preferably, the ultrasonic detection component is an ultrasonic sensor 8 disposed on the guide sleeve 7. The displacement detection component includes a laser displacement sensor 5 and a reflector 6 disposed on the housing and the guide sleeve 7, respectively. This embodiment detects the penetration depth of the probe into the concrete sample by the laser displacement sensor 5 and the reflector 6, which greatly improves the measurement accuracy of the penetration depth compared to the prior art of manual measurement by a measuring ruler, thereby reducing the detection error of the concrete strength. The mechanical detection component is a force sensor 4.

[0085] The control component 9 specifically includes a signal conversion module, a single-chip processing module and a storage module. The signal conversion module is used to receive and convert the detection signals of the mechanical detection component, the displacement detection component and the ultrasonic detection component, and transmit the detection signals to the single-chip processing module. The single-chip processing module is used to process the penetration resistance fed back by the mechanical detection component and the penetration depth fed back by the displacement detection component to calculate the strength of the concrete, and is also used to calculate the reference strength of the concrete based on the detection signal fed back by the ultrasonic detection component converted by the signal conversion module. In addition, the single-chip processing module can also compare the strength of the concrete with the reference strength of the concrete. The storage module is used to store the penetration resistance and penetration depth of the effective test points, and is also used to store the detection signal of the ultrasonic component processed by the single-chip processing module.

[0086] In this embodiment, an indicator assembly 10 is also provided on the housing, and the indicator assembly 10 can be an indicator light or a buzzer. When either the penetration resistance or the penetration depth of the probe 1 into the concrete reaches a preset value, the indicator light is on, or the buzzer sounds an alarm, so that the operator stops the penetration of the probe 1. In order to make the measuring device more intelligent, in this embodiment, a display screen 11 and a button 12 can also be provided on the housing, and the indicator assembly 10, the display screen 11 and the button 12 are all electrically connected to the control assembly 9.

[0087] Furthermore, a power supply component 13 is provided inside the housing for supplying power to the control component, the indicating component, the display screen, the buttons and other structural components. A handle 14 is provided at the other end of the housing, i.e., the rear end of the housing, so that the operator can grasp it with one hand and push the probe into the concrete sample.

[0088] In this embodiment, the measuring needle 1, the drill chuck 2, the connecting rod 3, the guide sleeve 7 and the handle 14 are coaxially arranged, and the axial penetration resistance is transmitted in sequence by the measuring needle, the drill chuck, the connecting rod, the force sensor, the housing and the handle.

[0089] The concrete strength detection device of this embodiment can also be connected to external devices through a USB interface or the like for data transmission, storage, analysis, etc.

[0090] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for detecting concrete strength, characterized in that: The concrete strength detection device used in the detection method comprises: a housing, a probe disposed at one end of the housing, a mechanical detection component connected to the probe, a displacement detection component disposed on the housing and outside the probe, and a control component disposed inside the housing; The concrete strength testing method includes the following steps: S1: Zero the concrete strength testing device; S2: Push the measuring needle into the concrete sample to be tested. When any one of the penetration resistance and the penetration depth of the measuring needle detected by the mechanical detection component and the displacement detection component reaches a preset value, stop pushing the measuring needle and pull out the measuring needle; S3: Determine whether the corresponding test point is valid when the probe stops advancing. If it is valid, proceed to step S4; if it is invalid, return to step S1 and continue to execute downward; S4: The control component calculates the concrete strength of the corresponding test point according to the ratio of the penetration resistance and the penetration depth when the measuring needle stops advancing; S5: Return to step S1 and continue to execute downward, collect concrete strength data of multiple valid test points, and calculate the average value to obtain the strength of the tested concrete sample.

2. The concrete strength detection method according to claim 1, characterized in that: A guide sleeve capable of moving relative to the measuring needle is arranged on the outer side of the measuring needle; In step S1, the relative positions of the measuring needle and the guide sleeve are adjusted, and then zeroing is performed.

3. The concrete strength detection method according to claim 1, characterized in that: The diameter of the measuring needle is 1-2mm; In step S2, the measuring needle is pushed into the concrete sample (15) to be tested at a constant speed of 2-5 mm / s.

4. The concrete strength detection method according to claim 1, characterized in that: In step S2, the preset value of the penetration resistance is 300-400N, and the preset value of the penetration depth is 10-15mm.

5. The concrete strength detection method according to claim 1, characterized in that: In step S3, whether the corresponding test point is valid is determined based on whether cracks occur at the test point. If cracks occur around the test point during the test, the test is invalid. If there are no cracks around the test point, or cracks occur after the probe is pulled out, the test is valid.

6. The concrete strength detection method according to claim 2, characterized in that: The concrete strength detection device also includes an ultrasonic detection component arranged on the guide sleeve; In step S4, the control component also calculates the concrete strength obtained by ultrasonic detection according to the detection signal fed back by the ultrasonic detection component, and records it as the reference strength; In step S5, after collecting concrete strength data of 6-10 groups of effective test points, the average value of the concrete strength data is compared with the reference strength. If the relative error between the two is less than 15%, the strength test of the tested concrete sample (15) at this age is completed; if the relative error between the two is greater than 15%, return to step S1 and continue to execute downward, obtain more concrete strength data of effective test points, recalculate the average value, and compare it with the reference strength again until the relative error between the two is less than 15%.

7. A concrete strength detection device used in the detection method according to any one of claims 1 to 6, characterized in that: It comprises a housing, a measuring needle (1), a mechanical detection component, a displacement detection component and a control component (9); The measuring needle (1) is arranged at one end of the housing; The mechanical detection component is connected to the measuring needle (1) and is used to detect the penetration resistance of the measuring needle (1) into concrete; The displacement detection component is arranged on the housing and on the outside of the measuring needle (1) and is used to detect the penetration depth of the measuring needle (1) into concrete; The control component (9) is arranged inside the housing and is used to receive and transform the detection signals of the mechanical detection component and the displacement detection component, and process the detection signals to obtain the strength of the concrete according to the ratio of the penetration resistance to the penetration depth.

8. The concrete strength detection device according to claim 7, characterized in that: It also includes an ultrasonic detection component disposed at the front end of the housing, the ultrasonic detection component being used to detect the reference strength of the concrete; The control component (9) is also used to receive and convert the detection signal of the ultrasonic detection component, and compare the strength of the concrete obtained through the detection signals of the mechanical detection component and the displacement detection component with the reference strength of the concrete obtained through the detection of the ultrasonic detection component.

9. The concrete strength detection device according to claim 7, characterized in that: The diameter of the measuring needle (1) is 1-2 mm.

10. The concrete strength detection device according to claim 8, characterized in that: A guide sleeve (7) is arranged on the outer side of the measuring needle (1), and the guide sleeve (7) is capable of moving relative to the measuring needle (1); The ultrasonic detection component is an ultrasonic sensor (8) arranged on the guide sleeve (7).

11. The concrete strength detection device according to claim 10, characterized in that: The mechanical detection component is connected to the measuring needle (1) via a connecting rod (3) and a drill chuck (2); the measuring needle (1) is connected to the connecting rod (3) via the drill chuck (2); and the other end of the connecting rod (3) is connected to the mechanical detection component; The drill chuck (2) is partially arranged inside the guide sleeve (7); the guide sleeve (7) is movable relative to the drill chuck (2); the drill chuck (2) and the guide sleeve (7) are clearance-matched; the outer diameter of the drill chuck (2) is smaller than the inner diameter of the guide sleeve (7).

12. The concrete strength detection device according to claim 10, characterized in that: The displacement detection component comprises a laser displacement sensor (5) and a reflective sheet (6) which are respectively arranged on the housing and the guide sleeve (7); The mechanical detection component is a force sensor (4).

13. The concrete strength detection device according to claim 8, characterized in that: The control component (9) comprises a signal conversion module, a single-chip processing module and a storage module, wherein the signal conversion module is used to receive and convert detection signals of the mechanical detection component, the displacement detection component and the ultrasonic detection component, and transmit the detection signals to the single-chip processing module; The single-chip processing module is used to process the detection signal to obtain the strength of the concrete and the reference strength of the concrete; the single-chip processing module is also used to compare the strength of the concrete obtained by the detection signals of the mechanical detection component and the displacement detection component with the reference strength of the concrete obtained by the ultrasonic detection component; The storage module is used to store the penetration resistance and penetration depth of the effective test points, and is also used to store the detection signal of the ultrasonic component processed by the single-chip processing module.

14. The concrete strength detection device according to claim 7, characterized in that: The housing is also provided with an indication component (10), which is an indicator light or a buzzer. When any one of the penetration resistance and the penetration depth of the probe (1) into the concrete reaches a preset value, the indication component (10) gives an indication.

15. The concrete strength detection device according to claim 14, characterized in that: A display screen (11) and a button (12) are also provided on the housing, and the indicating component (10), the display screen (11) and the button (12) are all electrically connected to the control component (9); A power supply component (13) is also arranged inside the housing; A handle (14) is provided at the other end of the housing.

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