Device and method for testing interfacial adhesive force of concrete slip form template based on electroosmosis effect

Abstract

The invention discloses a device and a method for testing the interface adhesive force of a concrete slip form based on an electroosmosis effect. The device comprises a lifting device, an electronic spring vertical dynamometer, an electroosmosis device and a sample container, wherein the upper part and the left side surface of the sample container are opened. The lifting device comprises an L-shaped bearing platform support, the L-shaped bearing platform support is provided with a storage battery, a brushless direct current motor and an electronic spring vertical dynamometer which are sequentially connected, and a first force measuring hook of the electronic spring vertical dynamometer is connected with the output end of the brushless direct current motor through a first force measuring hanging line. A second force measuring hook of the electronic spring vertical dynamometer is connected with a pull rope through a second force measuring hanging line; the electroosmosis device comprises a direct-current stabilized power supply, a potential acquisition device and a humidity acquisition device. According to the invention, electro-osmosis is carried out on concrete through the electro-osmosis device, and the tensile force of the slip-form template is increased, so that the interface adhesive force test of the concrete slip-form template after electro-osmosis is realized.

Description

Technical Field

[0001] The invention relates to a testing device, in particular to a testing device and a testing method for the interface adhesion of a concrete slip formwork based on the electroosmotic effect. Background Art

[0002] Slipform concrete construction technology is a construction method used for large-scale vertical or near-vertical concrete structures. It uses a movable formwork system that slides along the construction surface during the concrete hardening process. This technology can increase construction speed, reduce joints, and optimize structural quality. In the slipform concrete construction process of the surge chamber of a large hydropower station, slipform concrete construction technology has been widely used due to its high efficiency and high quality. However, the problem of interfacial adhesion between concrete and the slipform formwork during slipform concrete construction has always been one of the key difficulties in the implementation of the technology. The magnitude of this interfacial adhesion directly affects the demoulding effect in slipform concrete construction, and thus affects the construction efficiency and the quality of the concrete surface.

[0003] Traditional slipforms are prone to excessive adhesion during demoulding, resulting in concrete surface defects and a large number of concrete blocks adhering to the template interface after the slipform is separated from the concrete. To solve this problem, the electrical testing technology currently used evaluates adhesion by measuring the change in resistance or capacitance between the concrete and the slipform interface. However, this technology requires specialized equipment for calibration, and the test accuracy is easily affected by environmental conditions. Summary of the invention

[0004] The purpose of the present invention is to provide a concrete slipform interface adhesion test device and test method based on the electroosmosis effect, by which the concrete is electroosmotically exposed to the electroosmosis device and the slipform is tensilely lifted to achieve concrete slipform interface adhesion test after electroosmosis.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A concrete formwork adhesion test device based on electroosmosis effect, comprising a lifting device, an electronic spring vertical dynamometer, an electroosmosis device and a sample container with openings on the upper part and the left side; the lifting device comprises an L-shaped support bracket, on which a battery, a brushless DC motor and an electronic spring vertical dynamometer connected in sequence are arranged, a first force measuring hook of the electronic spring vertical dynamometer is connected to the output end of the brushless DC motor through a first force measuring hanging line, and a second force measuring hook of the electronic spring vertical dynamometer is connected to a tension rope through a second force measuring hanging line; the electroosmosis device The device includes a DC regulated power supply, and a potential collection device and a humidity collection device which are inserted into and immersed in a sample container containing a concrete sample. The DC regulated power supply is connected to a cathode power supply line and an anode power supply line. The anode power supply line is connected to two anode copper rods inserted into the sample container containing the concrete sample. The cathode power supply line is connected to a cathode slipform template arranged at the opening on the left side of the sample container. A tension fastener connected to a tension rope is arranged on the cathode slipform template. An insulating composite plate is arranged on the right side of the sample container and the periphery of the cathode slipform template for fixing.

[0007] Furthermore, the potential collection device comprises a potential collector, which is connected to a plurality of potential measuring needles inserted into a sample container containing the concrete sample via a potential measuring needle connection line.

[0008] Furthermore, the humidity collection device comprises a humidity collector, which is connected to a plurality of humidity sensor probes inserted into a sample container containing the concrete sample via humidity sensor probe wires.

[0009] Furthermore, the second force measuring hanging wire is connected with a tension rope via a directional pulley arranged on the L-shaped support bracket.

[0010] Furthermore, the first force measuring hanging wire and the second force measuring hanging wire are of equal length.

[0011] Furthermore, the L-shaped support bracket is also provided with an inclined support to provide additional supporting force.

[0012] A testing method for a concrete slipform interface adhesion testing device based on electroosmotic effect comprises the following steps:

[0013] Step 1: Fit the cathode slipform template tightly to the left side of the sample container, and fix the right side of the sample container and the outer side of the cathode slipform template with an insulating composite plate; then, fix the tension fastener to the cathode slipform template, and connect the tension rope to the tension fastener; finally, connect the tension rope to the electronic spring vertical dynamometer and the lifting device;

[0014] Step 2: Pour the concrete sample into the sample container and vibrate the concrete sample with a concrete vibrator for 2 minutes;

[0015] Step 3, insert and immerse the potential probe connected to the potential collector and the potential probe connection line, the humidity sensor probe connected to the humidity collector and the humidity sensor probe connection line, and the two anode copper rods connected to the anode power supply connection line of the DC regulated power supply into the concrete sample, and connect the cathode power supply connection line of the DC regulated power supply to the cathode slipform template; then use a concrete vibrator to perform a secondary vibration on the concrete sample for 1 minute to ensure that the sample is dense, bubble-free and fully filled in the sample container;

[0016] Step 4: Keep the DC regulated power supply turned on and set the output voltage to 22V for 10 minutes of electroosmosis;

[0017] Step 5: After electroosmosis, manually lift the tension rope to check the adhesion effect between the cathode slipform and the concrete sample interface. If you feel adhesion resistance when lifting it lightly, the adhesion between the cathode slipform and the concrete sample interface is normal and the conditions for lifting and measuring force are met;

[0018] Step 6: Turn on the brushless DC motor connected to the battery. The brushless DC motor rotates slowly and uniformly. The tension rope drives the cathode slipform template to rise vertically and uniformly. The electronic spring vertical dynamometer begins to slowly pull and measure the force until the cathode slipform template completely leaves the contact surface on the left side of the sample container. The maximum tension reading of the electronic spring vertical dynamometer is recorded, and the adhesion between the concrete sample after electroosmosis treatment and the cathode slipform template is calculated:

[0019] Where σ is the adhesion force per unit contact area of ​​the sample container, in MPa; F is the maximum tension reading of the electronic spring vertical dynamometer, in N; A is the contact area between the concrete sample and the cathode slipform, in mm 2 .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention realizes the test of the adhesion force of the concrete slip formwork interface under the action of electroosmosis by means of a lifting device, an electronic spring vertical dynamometer, an electroosmosis device and a sample container. During the test, the electroosmosis is performed by applying a voltage to the concrete sample. Under the action of the electric field, the water molecules of the concrete sample migrate from the anode to the cathode, and the water molecules after the water migration condense between the concrete sample and the slip formwork interface and form a thin water film, which can reduce the adhesion force between the slip formwork and the concrete sample. Subsequently, the template is lifted. During the lifting process, the electronic spring vertical dynamometer can monitor and record the changes in the interface adhesion force in real time to ensure the accuracy and reliability of the measurement data.

[0022] The present invention uses an electroosmosis device to electroosmosis the concrete and lifts the slipform template to achieve the concrete slipform template interface adhesion test after electroosmosis. Compared with the prior art, the device can electroosmosis the concrete and lift the slipform at the same time, achieving the concrete slipform template interface adhesion test under the action of electroosmosis, improving its efficiency and scientificity, and also providing a reliable test method for electroosmosis concrete demoulding technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the positional relationship of each sub-device in the electroosmosis device of the present invention in the sample container;

[0025] In the figure: 1-brushless DC motor; 2-brushless motor power supply connection; 3-battery; 4-L-type support bracket; 5-potential collector; 6-first force measuring hook; 7-electronic spring vertical dynamometer; 8-directional pulley; 9-tension rope; 10-tension fastener; 11-oblique support; 12-cathode slip form template; 13-insulating composite board; 14-potential measuring needle connection; 15-cathode power supply connection; 16-sample container; 17-potential measuring needle; 18-anode copper rod; 19-anode power supply connection; 20-humidity sensor needle; 21-humidity sensor needle connection; 22-DC regulated power supply; 23-humidity collector; 24-first force measuring hanging line; 25-second force measuring hanging line; 26-second force measuring hook. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1 , 2 As shown, a concrete slipform interface adhesion testing device based on the electroosmotic effect described in this embodiment includes a lifting device, an electronic spring vertical dynamometer 7, an electroosmotic device and a sample container 16 with openings on the top and left side.

[0028] The lifting device includes an L-shaped support bracket 4, on which a battery 3, a brushless DC motor 1 and an electronic spring vertical dynamometer 7 connected in sequence are arranged. The battery 3 is connected to the brushless DC motor 1 through a brushless motor power supply line 2 to provide the electric energy required by the motor. The first force measuring hook 6 of the electronic spring vertical dynamometer 7 is connected to the output end of the brushless DC motor 1 through a first force measuring hanging line 24. The second force measuring hook 26 of the electronic spring vertical dynamometer 7 is connected to a tension rope 9 through a second force measuring hanging line 25 via a directional pulley 8 arranged on the L-shaped support bracket 4. Guiding and adjusting the direction of force through the directional pulley 8 helps to reduce friction and wear and improve the working efficiency and stability of the device. The first force measuring hanging line 24 is equal in length to the second force measuring hanging line 25, which can ensure that the transmission and measurement of force remain consistent in the device, thereby improving the accuracy and reliability of the measurement. An oblique support 11 is also provided in the L-shaped base bracket 4. The L-shaped base bracket 4 is made of wood, and the oblique support 11 is made of stainless steel. The oblique support 11 can be installed in the L-shaped base bracket 4 by screws, thereby enhancing the stability and rigidity of the L-shaped base bracket 4, and reducing lateral displacement and deformation by providing additional supporting force, thereby ensuring that the entire structure remains stable under load.

[0029] The electronic spring vertical dynamometer 7 is a WDF-500 digital push-pull dynamometer that can output a force measurement curve, with an accuracy of ±1% and a minimum resolution of 0.01N. The electronic spring vertical dynamometer 7 has an electrical display function, which can accurately measure and display the force in the vertical direction, making it convenient for users to quickly and intuitively obtain data for monitoring and analysis. The force measurement stroke of the electronic spring vertical dynamometer 7 is 10mm, and the maximum load is 500N. Utilizing the principles of spring mechanics and modern electronic sensing technology, the dragging speed is stable and the force measurement is accurate. The electronic spring vertical dynamometer 7 and the force measurement hanging wire were purchased from Wenzhou Wei Measuring Instrument Co., Ltd.

[0030] The electroosmosis device includes a DC stabilized power supply 22, a potential collection device and a humidity collection device. The potential collection device includes a potential collector 5. The potential collector 5 is connected to a plurality of potential probes 17 inserted into a sample container 16 containing a concrete sample through a potential probe connection line 14. The material of the potential probes 17 is copper sulfate. The humidity collection device includes a humidity collector 23. The humidity collector 23 is connected to a plurality of humidity sensor probes 20 inserted into a sample container 16 containing a concrete sample through a humidity sensor probe connection line 21. The material of the humidity sensor probes 20 is graphite and carbon material. The DC stabilized power supply 22 is connected to a cathode power connection line 15 and an anode power connection line 19. The anode power connection line 19 is connected to two anode copper rods 18 inserted into a sample container 16 containing a concrete sample. The material of the anode copper rods 18 is brass. The cathode power supply connection line 15 is connected to the cathode slip form template 12 set at the left side opening of the sample container 16. The cathode slip form template 12 is perpendicular to the bottom and side of the sample container 16. The cathode slip form template 12 is a stainless steel plate. The cathode slip form template 12 is provided with a tension fastener 10 connected to the tension rope 9. The right side of the sample container 16 and the periphery of the cathode slip form template 12 are fixed with an insulating composite board 13. The shape of the sample container 16 is a rectangular square tube. The size of the sample container 16 is 120mm×350mm×120mm. The material of the sample container 16 is PVC insulation material. The material of the outer insulating composite board 13 is wood. The outer insulating composite board is nailed with cement nails, which has good stability while maintaining insulation.

[0031] A test method for a concrete slipform interface adhesion test device based on electroosmotic effect:

[0032] Step 1: fit the cathode slipform template 12 tightly to the left side of the sample container 16, and fix the right side of the sample container 16 and the outer side of the cathode slipform template 12 with the insulating composite plate 13; then, fix the tension fastener 10 to the cathode slipform template 12, and connect the tension rope 9 to the tension fastener 10; finally, connect the tension rope 9 to the electronic spring vertical dynamometer 7 and the lifting device;

[0033] Step 2: pour the concrete sample into the sample container 16, and vibrate the slipform concrete sample with a concrete vibrator for 2 minutes;

[0034] Step 3, insert and immerse the potential probe 17 connected to the potential collector 5 and the potential probe connection line 14, the humidity sensor probe 20 connected to the humidity collector 23 and the humidity sensor probe connection line 21, and the two anode copper rods 18 connected to the anode power connection line 19 of the DC stabilized power supply 22 into the concrete sample, and connect the cathode power connection line 15 of the DC stabilized power supply 22 to the cathode slip form template 12; then use a concrete vibrator to perform secondary vibration on the concrete sample for 1 minute to ensure that the concrete sample in the sample container 16 is dense, bubble-free and fully filled;

[0035] Step 4: Keep the DC regulated power supply 22 turned on, and set the output voltage to 22V for 10 minutes of electroosmosis;

[0036] Step 5: After electroosmosis, manually lift the tension rope 9 that carries the lifting force to check the adhesion effect between the cathode slipform template 12 and the concrete sample interface. If the adhesion resistance is felt when lightly lifting, the adhesion between the cathode slipform template 12 and the concrete sample interface is normal and meets the lifting force measurement conditions;

[0037] Step 6: Turn on the brushless DC motor 1 connected to the battery 3, the brushless DC motor 1 rotates slowly and uniformly, the tension rope 9 drives the cathode slipform template 12 to rise vertically and uniformly, and the electronic spring vertical dynamometer 7 starts to slowly pull and measure the force until the cathode slipform template 12 completely leaves the contact surface on the left side of the sample container 16, and the maximum tension reading of the electronic spring vertical dynamometer 7 is recorded, and the adhesion between the concrete sample after electroosmosis treatment and the cathode slipform template 12 is calculated:

[0038] Wherein σ is the adhesion force per unit contact area of ​​the sample container 16, in MPa; F is the maximum tension reading of the electronic spring vertical dynamometer 7, in N; A is the contact area between the concrete sample and the cathode slipform template 12, in mm 2 ;

[0039] Step 7: Calculate the electroosmotic permeability coefficient between the concrete sample after electroosmotic treatment and the cathode slipform template 12:

[0040] Where ke is the electroosmotic permeability coefficient, in m2 / (s·V); Q e is the amount of water seepage from the anode to the cathode in the concrete sample collected by the humidity collector 23 per unit time, in m 3 / s; ΔV is the potential difference in the concrete sample collected by the potential collector 5, in V; ΔL is the spacing distance of the potential probes (17) in the concrete sample, in m;

[0041] Step 8: Keep the other parameters unchanged, change the voltage value of the DC regulated power supply 22, repeat the above steps, obtain the adhesion force F and the electroosmotic permeability coefficient ke of the interface under different voltage conditions, and derive the influence of different voltages on the adhesion force F and the electroosmotic permeability coefficient ke of the interface; or change the concrete mix ratio, repeat the above steps, obtain the adhesion force F and the electroosmotic permeability coefficient ke of the interface with different concrete mix ratios, and further study the influence of the mix ratio on the adhesion force F and the electroosmotic permeability coefficient ke of the interface; in addition, other factors such as the material of the metal template can also be changed to study the influence of different factors on the adhesion force F and the electroosmotic permeability coefficient ke of the interface;

[0042] Step 10: Obtain the remaining physical parameters of the concrete sample and close the testing device.

[0043] The method for obtaining the remaining physical parameters of the concrete sample is based on the civil engineering test specification operation method, which includes the compressive strength test method, density and volume mass test method. The remaining physical parameters of the concrete sample include the moisture content of the slipform concrete sample near the cathode slipform template 12 and the anode copper rod 18.

Claims

1. A concrete slip formwork interface adhesion test device based on electroosmotic effect, characterized in that: It comprises a lifting device, an electronic spring vertical dynamometer (7), an electroosmotic device and a sample container (16) with openings on the top and left side; The lifting device comprises an L-shaped support bracket (4), on which a battery (3), a brushless DC motor (1) and an electronic spring vertical dynamometer (7) connected in sequence are arranged, a first force measuring hook (6) of the electronic spring vertical dynamometer (7) being connected to the output end of the brushless DC motor (1) via a first force measuring hanging line (24), and a second force measuring hook (26) of the electronic spring vertical dynamometer (7) being connected to a tension rope (9) via a second force measuring hanging line (25); The electroosmosis device comprises a DC regulated power supply (22) and a potential collection device and a humidity collection device inserted into and immersed in a sample container (16) containing a concrete sample. The DC regulated power supply (22) is connected to a cathode power supply connection line (15) and an anode power supply connection line (19). The anode power supply connection line (19) is connected to two anode copper rods (18) inserted into the sample container (16) containing the concrete sample. The cathode power supply connection line (15) is connected to a cathode sliding formwork (12) arranged at the left side opening of the sample container (16). A tension fastener (10) connected to a tension rope (9) is arranged on the cathode sliding formwork (12). An insulating composite plate (13) is arranged on the right side of the sample container (16) and the periphery of the cathode sliding formwork (12) for fixing.

2. The concrete slip form interface adhesion testing device based on electroosmotic effect according to claim 1 is characterized in that: The potential collection device comprises a potential collector (5), wherein the potential collector (5) is connected to a plurality of potential measuring needles (17) inserted into a sample container (16) containing a concrete sample via a potential measuring needle connection line (14).

3. The concrete slip form interface adhesion testing device based on electroosmotic effect according to claim 2 is characterized in that: The humidity collection device comprises a humidity collector (23), wherein the humidity collector (23) is connected to a plurality of humidity sensor probes (20) inserted into a sample container (16) containing a concrete sample via a humidity sensor probe connection line (21).

4. The device for testing the interface adhesion of concrete slipform based on electroosmotic effect according to claim 3 is characterized in that: The second force measuring hanging wire (25) is connected to a tension rope (9) via a directional pulley (8) provided on the L-shaped support bracket (4).

5. The device for testing the interface adhesion of concrete slipform based on electroosmotic effect according to claim 4, characterized in that: The first force measuring hanging wire (24) and the second force measuring hanging wire (25) are of equal length.

6. The device for testing the interface adhesion of concrete slipform based on electroosmotic effect according to claim 5, characterized in that: The L-shaped support bracket (4) is also provided with an inclined support (11) for providing additional supporting force.

7. A testing method using the concrete slip form interface adhesion testing device based on electroosmotic effect as claimed in claim 6, characterized in that: The following steps are involved: Step 1: The cathode sliding mold template (12) is tightly fitted to the left side of the sample container (16), and the right side of the sample container (16) and the outer side of the cathode sliding mold template (12) are fixed with an insulating composite plate (13); then, a tension fastener (10) is fixed to the cathode sliding mold template, and a tension rope (9) is connected to the tension fastener (10); finally, the tension rope (9) is connected to an electronic spring vertical dynamometer (7) and a lifting device; Step 2: pour the concrete sample into the sample container (16), and vibrate the concrete sample with a concrete vibrator for 2 minutes; Step 3, inserting and immersing the potential probe (17) connected to the potential collector (5) and the potential probe connection line (14), the humidity sensor probe (20) connected to the humidity collector (23) and the humidity sensor probe connection line (21), and two anode copper rods (18) connected to the anode power connection line (19) of the DC stabilized power supply (22) into the concrete sample, and connecting the cathode power connection line (15) of the DC stabilized power supply (22) to the cathode sliding formwork (12); then using a concrete vibrator to perform secondary vibration on the concrete sample for 1 minute to ensure that the concrete sample in the sample container (16) is dense, free of bubbles and fully filled; Step 4: Keep the DC regulated power supply (22) turned on, and set the output voltage to 22V for 10 minutes of electroosmosis; Step 5: After electroosmosis, manually lift the tension rope (9) to check the adhesion effect between the cathode sliding formwork (12) and the concrete sample interface. If adhesion resistance is felt when lightly lifting, the adhesion between the cathode sliding formwork (12) and the concrete sample interface is normal and the conditions for lifting and measuring force are met; Step 6: Turn on the brushless DC motor (1) connected to the battery, the brushless DC motor (1) rotates slowly and uniformly, the tension rope (9) drives the cathode slip form template (12) to rise vertically and uniformly, and the electronic spring vertical dynamometer (7) starts to slowly pull and measure the force until the cathode slip form template (12) completely leaves the left side contact surface of the sample container (16), and the maximum tension reading of the electronic spring vertical dynamometer (7) is recorded, and the adhesion between the concrete sample after electroosmosis treatment and the cathode slip form template (12) is calculated: Wherein σ is the adhesion force per unit contact area of ​​the sample container (16), in MPa; F is the maximum tension reading of the electronic spring vertical dynamometer (7), in N; Α is the contact area between the concrete sample and the cathode slipform template (12), in mm 2 .

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