Test device and method for batch test of accelerated erosion of concrete

Abstract

The invention provides a batch concrete accelerated erosion test device and a batch concrete accelerated erosion test method, relates to the field of durability tests, and aims to solve the problem that a plurality of samples are difficult to accurately test during an accelerated concrete erosion test at present, a clamp is arranged in an erosion box and a plurality of clamping positions are formed, so that test pieces with different sizes can be accommodated to simulate the erosion test; the water bath constant-temperature heating box is matched with the erosion box, so that the problem of crystal precipitation is avoided, the accuracy of test data is ensured, a plurality of test pieces are accelerated to be tested at the same time, and comparative research on erosion speed and distribution can be carried out on the test pieces with different sizes; a pulse electric field is adopted to replace a traditional stable electric field, bidirectional ion erosion is carried out on the test block, the test time is further shortened, and the test accuracy is improved.

Description

Technical Field

[0001] The invention relates to the field of durability testing, and in particular to a batch testing device and method for accelerated corrosion testing of concrete. Background Art

[0002] In the engineering application of cement concrete, the durability of concrete structure is a crucial indicator. The temperature, humidity and chemical ion erosion (such as sulfate) in the environment will have an impact on concrete, especially in coastal areas and saline soil and saline lake areas, where sulfate erosion is particularly destructive to concrete structures. The traditional concrete corrosion test process is often time-consuming, usually requiring more than 6 months, resulting in a high time cost for research and experiments. In order to accelerate this process, most of the current test devices use single control methods such as dry-wet cycles and electrical acceleration.

[0003] A Chinese patent (publication number: CN108226020A) discloses an electric accelerated concrete dissolution test device under complex environment, which maintains the temperature and ion concentration of the erosion solution for a long time to simulate the electric accelerated concrete dissolution under different conditions, provides direct current of different voltages, erosion solution temperature, and ion concentration according to demand, and can also monitor and adjust the test conditions in real time; the erosion solution is directly heated for simulation, but in the actual heating process, the change in solubility causes crystals to precipitate and adhere to the surface of internal components (constant temperature rod, electrode sheet, sensor), affecting the accuracy of the test data; in addition, the current device can only process a single sample, the test efficiency is low, and it is impossible to test multiple specimens at the same time. The existing device often ignores the simulation of complex factors such as temperature, humidity and ion concentration in the actual environment in the experiment, and fails to accurately reflect the concrete erosion process in the real environment. Summary of the invention

[0004] The purpose of the present invention is to provide a batch test device and method for accelerated corrosion of concrete in view of the defects of the prior art. A clamp is arranged in an corrosion box to form a plurality of clamping positions, which can accommodate specimens of different sizes to simulate corrosion tests. A water bath constant temperature heating box is used in conjunction with the corrosion box to avoid the problem of crystal precipitation, and multiple specimens can be accelerated tested at the same time, so that a comparative study of the corrosion rate and distribution of specimens of different sizes can be carried out.

[0005] The first object of the present invention is to provide a batch test device for accelerated corrosion of concrete, which adopts the following scheme:

[0006] Water bath;

[0007] The corrosion box is placed in the water bath box. A fixture for accommodating the specimen is installed inside the corrosion box. The fixture divides the corrosion box into two solution pools. The fixture is provided with multiple clamping positions for accommodating the specimen. The two sides of the specimen at the same clamping position are subjected to the action of solutions in different solution pools.

[0008] The pulse assembly includes a pulse power supply and electrodes. Electrodes are respectively arranged in each molten pool of the erosion box and are respectively connected to the pulse power supply to form an electrolytic cell.

[0009] Furthermore, a plurality of erosion boxes are arranged in the water bath box, and the clamping positions on the clamps in each erosion box are arranged in sequence and at intervals.

[0010] Furthermore, the fixture is provided with clamping positions of different specifications to match test pieces of different sizes, and a window is provided on the top of the clamping position.

[0011] Furthermore, a support frame, a heating element and a temperature sensor are provided in the water bath. The support frame carries the erosion box in the water bath. The heating element is located below the position where the support frame carries the erosion box. The temperature sensor measures the liquid temperature in the water tank and sends it to the controller.

[0012] Furthermore, liquid is injected into the water bath, the bottom of the corrosion box is immersed in the liquid in the water bath, the outside of the water bath is wrapped with a heat preservation layer, and the top opening of the water bath is matched with a cover.

[0013] Furthermore, a pH indicator is installed in the dissolution tank, and the pH indicator is used to measure the acidity and alkalinity value in the dissolution tank and send it to the controller.

[0014] Furthermore, an electrode in one molten pool in the erosion box is connected to a pulse power supply via a wire as an anode, and an electrode in another molten pool is connected to a pulse power supply via a wire as a cathode. Electrolytes are respectively injected into the molten pools, and the electrodes are porous electrode sheets.

[0015] The second object of the present invention is to provide a test method for batch testing of the concrete accelerated corrosion test device as described in the first object, comprising:

[0016] The test piece is mounted in the clamping position, and the electrolyte is injected into the dissolving pool so that the two sides of each test piece can be respectively exposed to the solution of different dissolving pools;

[0017] The corrosion chamber and its internal components are heated by a water bath to keep the time within the set temperature range, simulating the actual working temperature conditions;

[0018] Turn on the pulse power supply to form an electrolytic cell in the corrosion box through the electrodes to accelerate the corrosion of the test piece.

[0019] Furthermore, during the test, the temperature and pH value of the solution in the dissolution tank were measured.

[0020] Furthermore, the electrode serving as the anode is placed in the sulfate ion solution, and the electrode serving as the cathode is placed in the alkaline solution.

[0021] Compared with the prior art, the present invention has the following advantages and positive effects:

[0022] (1) In order to solve the problem that it is difficult to accurately test multiple specimens during the current accelerated concrete corrosion test, a fixture is set in the corrosion box to form multiple clamping positions, which can accommodate specimens of different sizes to simulate the corrosion test. A water bath constant temperature heating box is used in conjunction with the corrosion box to avoid the problem of crystal precipitation and ensure the accuracy of the test data. At the same time, multiple specimens can be accelerated to test, and the corrosion rate and distribution of specimens of different sizes can be compared. A pulse electric field is used instead of a traditional stable electric field to perform bidirectional ion corrosion on the test block, which further reduces the test time and improves the accuracy of the test.

[0023] (2) Through modular design, the fixture can adapt to the test requirements of specimens of different sizes, improving the flexibility of the test. A window is opened on the top of each test block position of the fixture to facilitate the placement, removal and observation of the corrosion of the test block. At the same time, it is also convenient to observe the matching effect between the test block and the clamping position, thereby meeting the sealing requirements.

[0024] (3) Without changing the mechanism of sulfate ion corrosion of concrete, the smooth side of the concrete is retained, which does not affect the subsequent mechanical properties test of the concrete specimens, providing an efficient and convenient batch testing method for the study of concrete performance under sulfate corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a cross-sectional schematic diagram of the accelerated corrosion test device for batch testing of concrete in Examples 1 and 2 of the present invention.

[0027] Figure 2 It is a schematic diagram of the test device for batch testing of accelerated corrosion of concrete in Examples 1 and 2 of the present invention.

[0028] Figure 3 Schematic diagram of the distribution of the water bath box and the corrosion box in Examples 1 and 2 of the present invention.

[0029] Figure 4 Schematic diagram of the heating element in the water bath in Examples 1 and 2 of the present invention.

[0030] Figure 5 Schematic diagram of the structure of the clamp in Examples 1 and 2 of the present invention.

[0031] Among them, 1. water bath; 2. support frame; 3. anode; 4. fixture; 5. test piece; 6. cathode; 7. dissolution tank; 8. corrosion box; 9. clamping position. DETAILED DESCRIPTION

[0032] Example 1

[0033] In a typical embodiment of the present invention, Figure 1-Figure 5 As shown, a batch test device for accelerated corrosion of concrete is provided.

[0034] Sulfate erosion is an important factor affecting the durability of concrete. Especially in different sulfate environments, such as different concentrations, different temperatures, and dry-wet cycles, the performance degradation of concrete materials is particularly significant. The current concrete accelerated erosion test equipment and methods have problems of low efficiency, accuracy and operability. Based on this, this embodiment provides a batch test concrete accelerated erosion test device, which uses a water bath constant temperature heating box in conjunction with an erosion box 8 to avoid the problem of crystal precipitation; uses porous electrodes and pulsed electric fields to reduce the impact of crystal precipitation and improves erosion efficiency; provides concrete test block fixtures 4 of different sizes, which can test multiple specimens 5 at the same time and improve experimental efficiency. The fixture 4 adopts a modular design to facilitate the test requirements of specimens 5 of different sizes.

[0035] like Figure 1 As shown, the batch test device for accelerated corrosion of concrete mainly includes a water bath 1, an erosion box 8 and a pulse assembly. A fixture 4 for accommodating a specimen 5 is installed inside the erosion box 8. The fixture 4 divides the erosion box 8 into two molten pools 7. The fixture 4 is provided with a plurality of clamping positions 9 for accommodating the specimen 5. The two sides of the specimen 5 at the same clamping position 9 are subjected to the action of solutions of different molten pools 7 to simulate the actual corrosion environment. At the same time, the erosion box 8 is heated by the water bath 1 to keep the temperature stable. The pulse assembly includes a pulse power supply and electrodes. By setting electrodes in each molten pool 7 and connecting to a pulse power supply, an electrolytic cell is formed. Compared with the traditional stable electric field, the pulse electric field can provide a stronger corrosion acceleration effect, thereby shortening the test cycle and improving the test efficiency.

[0036] In this embodiment, the fixture 4 divides the erosion box 8 into two molten pools 7, and is provided with a plurality of clamping positions 9, which can accommodate test pieces 5 of different sizes. It is possible to test a plurality of test pieces 5 at the same time, realize batch testing, improve the efficiency of the test, solve the problem that the current equipment can only test a small number of test pieces at a time, and can also set clamping positions 9 of different specifications on the same fixture 4, allowing for comparative study of the erosion rate and distribution of test pieces 5 of different sizes.

[0037] It should be pointed out that in the accelerated erosion test of concrete, specimens 5 of different sizes may indeed lead to differences in erosion rate and erosion distribution due to size differences. This is because the size of the specimen 5 affects the ratio of its surface area to volume, thereby affecting the penetration and diffusion rate of the erosion medium. Small-sized specimens 5 may show a greater erosion rate because they have a higher surface area to volume ratio, making it easier for the erosion medium to penetrate into the interior of the specimen 5. In addition, the geometry and size of the specimen 5 will also affect the flow pattern of the erosion medium and the progress of the erosion front.

[0038] The fixture 4 is provided with clamping positions 9 of different specifications to match the test pieces 5 of different sizes. The top of the clamping position 9 is provided with a window to simulate the erosion test of the test pieces 5 of different sizes. By setting concrete test block fixtures 4 of different sizes, multiple test pieces 5 can be tested simultaneously at an accelerated speed. For example, multiple clamping positions 9 of 40 mm and multiple clamping positions 9 of 100 mm are set on the same fixture 4 to accommodate 40 mm cubic test pieces 5 or 100 mm cubic test pieces 5, so that the erosion speed and distribution of the test pieces 5 of different sizes can be compared.

[0039] In addition, if Figure 5 As shown, after the prepared concrete specimen 5 is installed in the fixture 4 of the corrosion box 8, the gap between the concrete specimen 5 and the fixture 4 is sealed by epoxy resin to ensure that the solution does not leak. The design of the fixture 4 takes into account the irregularity of the test block, and a window is opened on the top of each test block position to facilitate the placement and removal of the test block and the observation of the corrosion condition, and also to facilitate the observation of the sealing effect of the epoxy resin.

[0040] The clamping position 9 on the fixture 4 is designed so that both sides of the specimen 5 at the same clamping position 9 are exposed to the solution of the different solvent tanks 7, ensuring that the specimen 5 is stably placed in the corrosion box 8 and can be evenly exposed to the corrosion solution, thereby improving the uniformity and accuracy of the test. The corrosion process is accelerated by the electrolysis principle, so that the specimen 5 experiences more significant corrosion in a shorter period of time, thereby speeding up the test process.

[0041] like Figure 2 As shown, a plurality of corrosion boxes 8 are placed in the water bath 1, and the clamping positions 9 on the clamp 4 in each corrosion box 8 are arranged in sequence and at intervals to meet the needs of batch testing. Figure 3 As shown, in this embodiment, three corrosion boxes 8 are placed in the water bath box 1, so that multiple groups of concrete specimens 5 can be tested simultaneously.

[0042] The fixture 4 in the corrosion box 8 separates two molten pools 7 in the corrosion box 8, respectively placing the anode 3 electrode sheet and the Na2SO4 solution, and the cathode 6 electrode sheet and the NaOH solution. The electrode sheets are fixed in the molten pool 7. At the same time, a pH indicator and a temperature sensor can also be installed in the molten pool 7 and connected to the controller. The controller can be an external computer, a single-chip microcomputer, etc.

[0043] In addition, the fixture 4 in the erosion box 8 can be replaced and is suitable for test pieces 5 of 40 mm and 100 mm in size, and is sealed and bonded by epoxy resin. Being able to simulate the erosion test of test pieces 5 of different sizes is particularly important for studying the influence of sulfate erosion on the performance of concrete structures. Test pieces 5 of different sizes may have different erosion speeds and erosion distributions due to their size differences. In this embodiment, by setting concrete test block fixtures 4 of different sizes, multiple test pieces 5 can be tested simultaneously at an accelerated speed, so that the performance changes of test pieces 5 of different sizes under sulfate erosion can be simulated and compared.

[0044] The water bath 1 is provided with a support frame 2, a heating element and a temperature sensor. The support frame 2 is used to carry the corrosion box 8 in the water bath 1 to ensure that the corrosion box 8 is stably placed to facilitate the corrosion test. Figure 4 As shown, the heating element is located below the position of the support frame 2 carrying the erosion box 8, and is used to heat the liquid in the water bath 1 to keep the temperature of the solution in the erosion box 8 constant. The heater can be an electric heating rod, a heating wire, etc. It is used to simulate the temperature conditions in the actual environment to ensure the reliability of the test. The temperature sensor can not only measure the problem of the solution in the dissolution pool 7, but also be arranged in the water bath 1, measure the liquid temperature in the water bath 1 and send it to the controller, so as to realize real-time monitoring and adjustment of the temperature in the water bath 1. The feedback control mechanism can ensure the precise control of the temperature in the erosion box 8, thereby improving the accuracy and repeatability of the test.

[0045] Liquid is injected into the water bath 1, and the bottom of the erosion box 8 is immersed in the liquid. The erosion box 8 is evenly heated by heat conduction of the liquid to avoid local overheating or uneven temperature. The liquid can be water, oil or a mixture thereof, which has a good heat transfer effect. The outside of the water bath 1 is wrapped with an insulation layer to reduce heat loss, improve heating efficiency, and keep the temperature in the water bath 1 stable.

[0046] The top of the water bath 1 is open, which is convenient for the operator to observe the situation in the corrosion box 8 and place and remove the test piece 5. The cover can block the opening, and the cover is connected to the opening of the water bath 1 through a mortise and tenon structure, and is provided with a rubber sealing ring, which can close the water bath 1 during the corrosion test to reduce the interference of the external environment on the test, such as temperature fluctuations, dust, etc.

[0047] like Figure 3As shown, a pH indicator is provided in the dissolving tank 7 to measure the acidity and alkalinity in the dissolving tank 7 and send it to the controller. The pH value of the etching solution is monitored in real time to understand the chemical changes in the etching process and facilitate the evaluation of the etching effect.

[0048] like Figure 1 As shown, the electrode of one bath 7 in the corrosion box 8 is used as the anode 3, and the electrode of the other bath 7 is used as the cathode 6, which are connected to the pulse power supply through a wire. Bidirectional ion corrosion is performed on the test block, which further reduces the test time and simulates the electrochemical corrosion process in the actual environment.

[0049] The electrode is a porous electrode sheet, which increases the contact area between the electrode and the solution, improves the electrolysis efficiency, and also reduces the problem of crystal precipitation. Electrolytes are injected into the dissolution pool 7 respectively. These electrolytes are prepared according to the test requirements and can simulate the corrosive medium in the actual environment. Not only does it improve the stability and reliability of the test, but it can also accurately control and monitor the erosion process, thereby obtaining more accurate test results.

[0050] Example 2

[0051] In another typical embodiment of the present invention, Figure 1-Figure 5 As shown, a test method for batch testing of concrete accelerated corrosion test device is provided, using the batch testing of concrete accelerated corrosion test device as in Example 1.

[0052] A test method for batch testing of a concrete accelerated corrosion test device, comprising:

[0053] The test piece 5 is mounted on the clamping position 9, and the electrolyte is injected into the dissolving pool 7, so that the two sides of each test piece 5 can be respectively exposed to the solution of the different dissolving pools 7;

[0054] The corrosion box 8 and its internal components are heated by the water bath 1 so that the time is kept within the set temperature range to simulate the actual working temperature conditions;

[0055] The pulse power supply is turned on to form an electrolytic cell in the corrosion box 8 through the electrodes, thereby accelerating the corrosion of the test piece 5 .

[0056] In this embodiment, combined with Figure 1-Figure 5 The test methods for batch testing of the accelerated corrosion test device for concrete include:

[0057] Step 1: According to the experimental requirements, prepare a plurality of concrete specimens 5. The required specimen 5 size can be 40 mm×40 mm×40 mm or 100 mm×100 mm×100 mm, and a concrete fixture 4 of corresponding size is selected.

[0058] Step 2: Install the prepared concrete specimen 5 in the concrete fixture 4 of the corrosion box 8. Seal the gap between the concrete specimen 5 and the fixture 4 with epoxy resin to ensure that the solution does not leak.

[0059] Step 3: Place the corrosion box 8 on the support frame 2 of the constant temperature water bath 1.

[0060] Step 4: Add Na2SO4 solution to one side of the etching box 8 and add NaOH solution to the other side.

[0061] Step 5: Insert the anode 3 electrode into the slot on the side of the Na2SO4 solution, and the cathode 6 electrode into the slot on the side of the NaOH solution, and make sure that the electrode is firmly fixed. Connect the electrode to the external power box through the wire.

[0062] Step 6: Install the pH indicator and temperature sensor on both sides of the etching box 8 respectively, and connect them to an external computer through wires to monitor the pH and temperature changes of the etching solution in real time.

[0063] Step 7: Adjust the heating element and set a suitable experimental temperature (20°C - 80°C) to simulate the temperature conditions of actual working conditions, ensuring that the solution in the corrosion box 8 is in a constant temperature environment.

[0064] Step 8: Seal the device with a rubber sealing ring and a cover to ensure the tightness of the device during the experiment.

[0065] Step 9: Turn on the pulse power supply and start the electric field. The electric field generated by the anode 3 electrode sheet and the cathode 6 electrode sheet will accelerate the migration of sulfate ions into the concrete specimen 5, thereby accelerating the corrosion process of the concrete. During the experiment, the changes in pH value, temperature and current density are recorded in real time.

[0066] On the basis of not changing the mechanism of concrete corrosion by sulfate ions, the smooth side of the concrete is retained, and the subsequent mechanical property test of the concrete specimen 5 is not affected, providing an efficient and convenient batch testing method for the study of concrete performance under sulfate corrosion.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A batch test device for accelerated corrosion of concrete, characterized in that: include: Water bath; The corrosion box is placed in the water bath box. A fixture for accommodating the specimen is installed inside the corrosion box. The fixture divides the corrosion box into two solution pools. The fixture is provided with multiple clamping positions for accommodating the specimen. The two sides of the specimen at the same clamping position are subjected to the action of solutions in different solution pools. The pulse assembly includes a pulse power supply and electrodes. Electrodes are respectively arranged in each molten pool of the erosion box and are respectively connected to the pulse power supply to form an electrolytic cell.

2. The batch testing device for accelerated corrosion of concrete as claimed in claim 1, characterized in that: A plurality of erosion boxes are arranged in the water bath box, and the clamping positions on the clamps in each erosion box are arranged in sequence and at intervals.

3. The batch testing device for accelerated corrosion of concrete as claimed in claim 2, characterized in that: The clamp is provided with clamping positions of different specifications to match test pieces of different sizes, and a window is provided on the top of the clamping position.

4. The batch testing device for accelerated corrosion of concrete as claimed in claim 1, characterized in that: The water bath is provided with a support frame, a heating element and a temperature sensor. The support frame carries an erosion box in the water bath. The heating element is located below the position where the support frame carries the erosion box. The temperature sensor measures the liquid temperature in the water tank and sends it to the controller.

5. The batch testing device for accelerated corrosion of concrete as claimed in claim 4, characterized in that: Liquid is injected into the water bath, the bottom of the erosion box is immersed in the liquid in the water bath, the outside of the water bath is wrapped with a heat preservation layer, and the top opening of the water bath is matched with a cover body.

6. The batch testing device for accelerated corrosion of concrete as claimed in claim 1, characterized in that: A pH indicator is installed in the dissolving pool, and the pH indicator is used to measure the acidity and alkalinity value in the dissolving pool and send it to the controller.

7. The batch testing device for accelerated corrosion of concrete as claimed in claim 6, characterized in that: The electrode in one molten pool in the erosion box is connected to a pulse power supply through a wire and serves as an anode, and the electrode in another molten pool is connected to a pulse power supply through a wire and serves as a cathode. Electrolytes are respectively injected into the molten pools, and the electrodes are porous electrode sheets.

8. A test method for batch testing of a concrete accelerated corrosion test device, using the batch testing of a concrete accelerated corrosion test device as claimed in any one of claims 1 to 7, characterized in that: include: The test piece is mounted in the clamping position, and the electrolyte is injected into the dissolving pool so that the two sides of each test piece can be respectively exposed to the solution of different dissolving pools; The corrosion chamber and its internal components are heated by a water bath to keep the time within the set temperature range, simulating the actual working temperature conditions; Turn on the pulse power supply to form an electrolytic cell in the corrosion box through the electrodes to accelerate the corrosion of the test piece.

9. The test method of batch testing concrete accelerated corrosion test device according to claim 8, characterized in that: During the test, the temperature and pH value of the solution in the dissolution pool were measured.

10. The test method of batch testing concrete accelerated corrosion test device according to claim 8, characterized in that: The electrode serving as the anode is placed in the sulfate ion solution, and the electrode serving as the cathode is placed in the alkaline solution.

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