Testing device for simulating long-term durability of grouting material under action of complex coupling environment

Abstract

The invention discloses a test device for simulating long-term durability of a grouting material under the action of a complex coupling environment, the device comprises a test box body, a steel spring plate, a ventilation system and a water circulation system, the test box body comprises a box body, a box cover, an observation window and a pedestal; the ventilation system comprises an air inlet, an air outlet, a hot air pump and a ventilation pipe; the water circulation system comprises an upper water injection port, a lower water outlet, an impermeability test water injection port, a hydraulic pump, a hydraulic pressure gauge and a water pipe. The device can simulate that the grouting material is in a complex environmental condition of dry-wet cycle, load (one-way or two-way), hydrostatic pressure and coupling effect of three factors, and can also be used for an anti-permeability test, a corrosion resistance test and a dynamic water test of a cubic grouting material test block. By assembling common materials and equipment, the effect of simulating the actual occurrence condition after the grouting material is solidified is achieved, and the device is suitable for simulating the situation of long-term action of loads and complex environmental conditions, and is particularly suitable for long-period durability tests with monthly and annual as time units.

Description

Technical Field

[0001] The present invention relates to a durability test device for grouting materials, and particularly to a test device for simulating the long-term durability performance of grouting materials under the action of a complex coupling environment. Background Art

[0002] During the construction of infrastructure such as tunnels, highways, railways, port terminals, etc., grouting materials are often used to reinforce the foundation. During the service period of grouting materials, they will be affected by loads, water pressure, and complex environmental factors, and the time span of the action is often in years. Based on this, it is urgent to design a practical durability test device suitable for simulating the long time period of grouting materials. Summary of the Invention

[0003] The present invention provides a test device for simulating the long-term durability performance of grouting materials under the action of a complex coupling environment by modifying common equipment and materials. This device can simulate the complex environmental conditions of grouting materials in dry-wet cycles, loads (uniaxial or biaxial), hydrostatic pressure, and the coupling action of the three factors. It can also conduct impermeability tests, corrosion resistance tests, and dynamic water tests on cubic grouting material specimens. The present invention realizes the effect of simulating the actual occurrence conditions of grouting materials after curing by assembling common materials and equipment, is suitable for simulating the long-term action of loads and complex environmental conditions, and is particularly suitable for long-term durability tests with time units of months and years.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A test device for simulating the long-term durability performance of grouting materials under the action of a complex coupling environment includes four parts: a test box body, a spring plate, a ventilation system, and a water circulation system. Among them:

[0006] The test box body includes a box body, a box cover, an observation window, and a pedestal; an observation window is reserved on the side of the box body for observing the test process; a square hole is reserved on the top surface of the box body for placing and taking out grouting material specimens during the test; the top surface of the box body is equipped with a box cover; the pedestal is used for placing grouting material specimens, and a middle hole of the pedestal is reserved in the middle part.

[0007] The spring plate is suspended and fixed on the side plate of the box body for applying unidirectional / bidirectional axial loads to the grouting material specimens.

[0008] The ventilation system includes an air inlet, an air outlet, a hot air pump, and a ventilation pipe; the air inlet is arranged at the upper part of the box body, the air outlet is arranged at the lower part of the box body, and the ventilation pipe is respectively connected to the hot air pump and the air inlet.

[0009] The water circulation system includes an upper water injection port, a lower water outlet, an impermeability test water injection port, a hydraulic pump, a hydraulic pressure gauge, and a water pipe. The upper water injection port is arranged at the upper part of the box body, the lower water outlet and the impermeability test water injection port are arranged at the bottom of the box body, and the impermeability test water injection port is communicated with the middle hole of the pedestal; the hydraulic pump is connected to the water pipe, the water pipe is respectively communicated with the upper water injection port and the impermeability test water injection port, and a hydraulic pressure gauge is arranged in the middle of the water pipe.

[0010] A method for conducting a load-dry and wet cycle durability test by using the above device includes the following steps:

[0011] Step 1: Install a spring plate and preset the applied load;

[0012] Step 2: Open the upper water injection port or open the upper water injection port and the lower water outlet, close the impermeability test water injection port, the air inlet, and the air outlet valves, start the hydraulic pump, and inject water into the box body to complete the wetting process;

[0013] Step 3: Open the air inlet and the air outlet, start the hot air pump, close the upper water injection port, the lower water outlet, and the impermeability test water injection port valves, and complete the drying process;

[0014] Step 4: Repeat the processes of Step 2 and Step 3 to complete the dry and wet cycle test.

[0015] A method for conducting an impermeability test by using the above device includes the following steps:

[0016] Step 1: Install a spring plate and preset the applied load;

[0017] Step 2: Open the impermeability test water injection port, inject pressurized water, and observe the water seepage condition at the top of the grouting material test block through the observation window.

[0018] A method for conducting a corrosion durability test by using the above device includes the following steps:

[0019] Step 1: Open the upper water injection port and inject a corrosive solution through the hydraulic pump;

[0020] Step 2: When the water injection depth exceeds the height of the grouting material test block, stop injecting the corrosive solution into the box body, close the upper water injection port, and let it stand for the time specified in the test plan.

[0021] A method for conducting a water pressure action durability test by using the above device includes the following steps:

[0022] Step 1: Install a spring plate, preset the applied load, and restrict the lateral freedom degree of the grouting material test block;

[0023] Step 2: Fill the box body with water before sealing the cover plate;

[0024] Step 3: Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the tank through the hydraulic pressure gauge.

[0025] A method for performing a load - water pressure durability test using the above - mentioned device, comprising the following steps:

[0026] Step 1: Install a spring plate and apply unidirectional / bidirectional axial load to the grouting material specimen.

[0027] Step 2: Fill the tank with water before sealing the cover plate.

[0028] Step 3: Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the tank through the hydraulic pressure gauge.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. The present invention solves the disadvantages of the existing durability test, such as high cost, complex operation, and difficulty in simulating the coupling effect of load and complex environment.

[0031] 2. The test device of the present invention can simulate complex actions such as water pressure, wet - dry cycle, and load. The materials and equipment of the test device are easy to obtain, greatly reducing the test cost, and are particularly suitable for long - term durability tests.

[0032] 3. By setting an air inlet, an air outlet, a water injection port, and a water outlet in the device tank, the present invention can realize the simulation of the wet - dry cycle process without repeatedly taking out the grouting material specimen. The tank can be sealed, and the hydraulic pump injects hydraulic pressure into the liquid in the tank through a water delivery pipe, extremely simply realizing the water pressure change and simulating the static water pressure storage conditions at different positions of the grouting material under different groundwater depths.

[0033] 4. The present invention designs a deformable steel spring plate to apply a load on the grouting material specimen, which can simulate unidirectional and bidirectional load actions; it can also restrict the lateral freedom of the grouting material specimen and provide lateral support for the impermeability test of the grouting material specimen. The staggered arrangement of the steel spring plates will generate gaps between the grouting material specimen and the steel plates, thereby ensuring the effective contact between the specimen and the liquid, and realizing the corrosion resistance test of the specimen by injecting a corrosive solution into the tank. Description of the Drawings

[0034] Figure 1 It is a three - dimensional structure schematic diagram of the durability test device;

[0035] Figure 2 It is a structure schematic diagram of the durability test device;

[0036] Figure 3 It is a three - dimensional schematic diagram of the spring plate;

[0037] Figure 4 It is a front view schematic diagram of the spring plate;

[0038] Figure 5 It is a schematic diagram of the cross-section force of the grouting material test block;

[0039] Figure 6 It is a front view schematic diagram of the rear plate of the spring plate;

[0040] Figure 7 It is a top view schematic diagram of the top surface of the box body;

[0041] Figure 8 It is a three-dimensional schematic diagram of the test device assembly;

[0042] In the figure, 1-box body, 2-box cover, 3-box cover handle, 4-observation window, 5-upper water injection port, 6-lower water outlet, 7-seepage resistance test water injection port, 8-air inlet, 9-air outlet, 10-grouting material test block, 11-front plate of the spring plate, 12-lightweight spring, 13-rear plate of the spring plate, 14-finished rolled thread steel, 15-test bench, 16-hydraulic pump, 17-hydraulic pressure gauge, 18-hot air pump, 19-ventilation pipe, 20-water pipe, 21-middle hole of the test bench, 22-backing plate, 23-bolt. Specific implementation mode

[0043] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings, but it is not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0044] The present invention provides a test device for simulating the long-term durability performance of grouting materials under the action of a complex coupling environment, as Figures 1 - 8 shown. The device is composed of four parts: a test box body, a steel spring plate, a ventilation system, and a water circulation system, wherein:

[0045] The test box body is composed of a box body 1, a box cover 2, a box cover handle 3, an observation window 4, and a test bench 15. The box body 1 is welded and sealed with steel plates. The observation window 4 is made of tempered glass. Both the box cover 2 and the box cover handle 3 are made of steel. An observation window 4 is reserved on the side of the box body 1 for observing the test process. The observation window 4 is installed on the outside of the box body and the box body and the tempered glass are bonded with epoxy resin adhesive. A square hole is reserved on the top surface of the box body 1 for placing and taking out the grouting material test block during the test process. The top surface of the box body 1 is equipped with a box cover 2. The box cover 2 is provided with a box cover handle 3 on its surface. After the sample is placed and fixed in the box body 1, the box cover 2 and the top surface of the box body 1 are bonded with epoxy resin adhesive. The test bench 15 is cylindrical and is used for placing the grouting material test block 10. A through hole with a small diameter - the middle hole 21 of the test bench is reserved in the middle part of the test bench 15 for the seepage resistance test.

[0046] The spring plate is composed of a front spring plate 11, a lightweight spring 12, a rear spring plate 13, a precision rolled threaded steel 14, a backing plate 22, and a bolt 23. Both the front spring plate 11 and the rear spring plate 13 are made of steel. The elastic force of the spring plate comes from the lightweight spring 12. The two ends of the lightweight spring 12 are respectively welded to the front spring plate 11 and the rear spring plate 13. And the rear spring plate 13 is fixedly connected to the precision rolled threaded steel 14 through the backing plate 22 and the bolt 23, and the precision rolled threaded steel 14 is fixed on the side plate of the box body. The test device applies a unidirectional / bidirectional axial load to the grouting material specimen through the spring plate. The initial total length l0 of the spring plate is slightly greater than the distance between the grouting material specimen and the side of the box body. After the spring plate is placed, the lightweight spring 12 will be slightly compressed, and the reaction force of the compressed elastic force will suspend and fix the spring plate between the side plate of the box body and the grouting material specimen. The four front spring plates 11 on the side of the box body are arranged in a staggered manner with the grouting material specimen 10 and are overlapped in sequence, ensuring that the four front spring plates 11 on the side just wrap the grouting material specimen 10, applying an axial load to the grouting material specimen 10 and playing a role in restricting lateral freedom. The liquid enters the specimen by means of the deformation of the grouting material specimen and the gaps between the front spring plates 11, effectively applying a water pressure to the grouting material specimen 10. A backing plate 22 and a bolt 23 are arranged at the lower part of the rear spring plate 13. The spring plate applies an axial load to the grouting material specimen through the elastic reaction force generated by compressing the lightweight spring. By turning the bolt 23 to change its position on the precision rolled threaded steel 14, the elastic force of the spring plate can be changed, and it can also be flexibly changed to a unidirectional or bidirectional load. Measuring the total length of the spring plate after deformation can determine the axial load value. During the impermeability test, by turning the bolt 23, the appropriate elastic reaction force is adjusted to realize the lateral restraint of the grouting material specimen 10, providing the necessary boundary conditions for the impermeability test. The width of the front spring plate 11 is greater than the width of the grouting material specimen 10. The staggered arrangement of the front spring plate 11 and the grouting material specimen 10 achieves the effect that the water pressure effectively penetrates into the grouting material specimen 10. The intersection point of the lightweight spring 12 and the front spring plate 11 is located at the quarter point of the two diagonals of the side of the grouting material specimen close to the square endpoints. The relationship between the elastic force of the spring plate and the length of the spring after deformation is:

[0047] F = 4 × k × (l0 - l)

[0048] In the formula, F is the elastic force of the spring plate, kN; k is the stiffness coefficient of each spring, kN / m; l0 is the initial length of the spring plate, m; l is the length of the spring plate after the test device is installed and fixed, m.

[0049] The ventilation system consists of an air inlet 8, an air outlet 9, a hot air pump 18, and a ventilation pipe 19. The ventilation system uses the ventilation pipe 19 to connect the hot air pump 18 and the air inlet 8 respectively. When the hot air pump 18 is turned on, the air inlet 8 and the air outlet 9 are opened simultaneously to quickly introduce dry hot air into the box to complete the drying process of the specimen. Since the density of hot air is less than that of cold air, the air inlet 8 is arranged at the upper part of the box body 1, and the air outlet 9 is arranged at the lower part of the box body 1, so as to drive the cold air out of the box by the directional circular movement of the dry hot air, achieving the effect of accelerating the drying speed. The air inlet 8 and the air outlet 9 are respectively arranged at the upper and lower 1 / 5 positions on the side of the box body.

[0050] The water circulation system consists of an upper water injection port 5, a lower water outlet 6, an anti-seepage test water injection port 7, a hydraulic pump 16, a hydraulic pressure gauge 17, and a water pipe 20. The upper water injection port 5 is arranged at the upper part of the box body 1, the lower water outlet 6 and the anti-seepage test water injection port 7 are arranged at the bottom of the box body 1, and the anti-seepage test water injection port 7 is communicated with the middle hole 21 of the pedestal. Valves are provided at the upper water injection port, the lower water outlet, and the anti-seepage test water injection port. The middle hole 21 of the pedestal includes four water injection holes. The water circulation system is connected to the hydraulic pump 16 through the water pipe 20. The water pipe 20 is used to transport hydraulic water. The water pipe 20 is respectively communicated with the upper water injection port 5 and the anti-seepage test water injection port 7. A hydraulic pressure gauge 17 is provided in the middle of the water pipe 20 to monitor and control the hydraulic pressure. After filling the box with water, open the upper water injection port 5, close the valves of the lower water outlet 6 and the anti-seepage test water injection port 7, apply water pressure to the box by the hydraulic pump 16, and monitor and control the water pressure by the hydraulic pressure gauge 17 to conduct a hydrostatic pressure test. Open the anti-seepage test water injection port 7 and the upper water injection port 5, close the valve of the lower water outlet 6, start the hydraulic pump 16, inject the hydraulic water from the anti-seepage test water injection port 7 into the grouting material specimen 10 through the middle hole 21 of the pedestal, so as to conduct an anti-seepage test on the grouting material specimen, and observe the water seepage situation through the observation window 4. Open the upper water injection port 5 and the lower water outlet 6, close the valve of the anti-seepage test water injection port 7, and conduct dynamic water curing or dynamic water test. Open the upper water injection port 5, close the valves of the lower water outlet 6 and the anti-seepage test water injection port 7, and inject corrosive solution into the box by the hydraulic pump 16 to conduct a corrosion resistance test.

[0051] A method for conducting a long-term durability test of grouting materials under the action of a simulated complex coupling environment using the above device includes the following steps:

[0052] Step S1: Weld the box body, weld and install water passing and air passing valves at the upper water injection port, the lower water outlet, the anti-seepage test water injection port, the air inlet, and the air outlet, arrange and debug the hot air pump and the hydraulic pump, and install the ventilation pipe and the water pipe pipelines.

[0053] Step S2: Place the grouting material test block on the pedestal, install and fix the spring plate to make it hang stably. According to the preset load value in the test plan, turn the bolt to adjust the elasticity of the spring plate, and determine the applied load value based on the length of the spring plate.

[0054] Step S3: After the installation and fixation of the grouting material test block and the spring plate and the application of the load, bond the top plate and the box cover with epoxy resin adhesive for sealing treatment. If required by the test plan, fill the box with water in advance before bonding the top plate and the cover to prevent the water from not filling the entire box due to the presence of air after the box is sealed.

[0055] Step S4: Open and close the valves according to Table 1 for different test contents to complete the corresponding tests.

[0056] Ⅰ. Load-dry and wet cycle durability test: Install the spring plate and preset the applied load; Open the upper water injection port (or open the upper water injection port and the lower water outlet), close other valves, start the hydraulic pump, and inject water into the box to complete the wetting process; Open the air inlet and outlet, start the hot air pump, and close other valves to complete the drying process. Repeat the above process to complete the dry and wet cycle test.

[0057] Ⅱ. Impermeability test: Install the spring plate and preset the applied load; Open the impermeability test water injection port, inject hydraulic water, and observe the water seepage condition at the top of the grouting material test block through the observation window.

[0058] Ⅲ. Corrosion durability test: Open the upper water injection port, inject the corrosive solution through the hydraulic pump. When the water injection depth exceeds the height of the grouting material test block, stop injecting the corrosive solution into the box, close the upper water injection port, and let it stand until the time specified in the test plan.

[0059] Ⅳ. Hydraulic pressure action durability test: Install the spring plate and preset the applied load (just restrict the lateral freedom of the grouting material test block); Fill the box with water before sealing the cover; Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the box through the pressure gauge.

[0060] Ⅴ. Load-hydraulic pressure durability test: Install the spring plate and preset the applied load (turn the bolt to apply a large load); Fill the box with water before sealing the cover; Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the box through the pressure gauge.

[0061] Table 1

[0062]

Claims

1. An experimental device for the long-term durability performance of grouting materials under the action of a simulated complex coupling environment, characterized in that The device includes four parts: a test box body, a spring plate, a ventilation system, and a water circulation system, where: The test box body includes a box body, a box cover, an observation window, and a pedestal; an observation window is reserved on the side of the box body for facilitating the observation of the test process; a square hole is reserved on the top surface of the box body for placing and taking out the grouting material test block during the test process; the box cover is provided on the top surface of the box body; the pedestal is used for placing the grouting material test block, and a middle hole of the pedestal is reserved in the middle part; The spring plate is suspended and fixed on the side plate of the box body for applying unidirectional / bidirectional axial load to the grouting material test block; The ventilation system includes an air inlet, an air outlet, a hot air pump, and a ventilation pipe; the air inlet is arranged at the upper part of the box body, the air outlet is arranged at the lower part of the box body, and the ventilation pipe is respectively connected to the hot air pump and the air inlet; The water circulation system includes an upper water injection port, a lower water outlet, an anti-seepage test water injection port, a hydraulic pump, a hydraulic gauge, and a water pipe. The upper water injection port is arranged at the upper part of the box body, the lower water outlet and the anti-seepage test water injection port are arranged at the bottom of the box body, and the anti-seepage test water injection port is communicated with the middle hole of the pedestal; the hydraulic pump is connected to the water pipe, the water pipe is respectively communicated with the upper water injection port and the anti-seepage test water injection port, and a hydraulic gauge is arranged in the middle of the water pipe.

2. The long-term durability performance test device for grouting materials under the action of a simulated complex coupling environment according to claim 1, characterized in that The box body is welded and sealed by steel plates, the observation window is made of toughened glass, and the box cover and the box cover handle are both made of steel.

3. The long-term durability performance test device for grouting materials under the action of a simulated complex coupling environment according to claim 1, wherein The spring plate is composed of a spring plate front plate, a lightweight spring, a spring plate rear plate, a precision rolled threaded steel, a backing plate, and a bolt. The two ends of the lightweight spring are respectively welded and connected to the spring plate front plate and the spring plate rear plate, and the spring plate rear plate is fixedly connected to the precision rolled threaded steel through the backing plate and the bolt, and the precision rolled threaded steel is fixed on the side plate of the box body.

4. The long-term durability performance test device for grouting materials under the action of a simulated complex coupling environment according to claim 3, characterized in that Both the spring plate front plate and the spring plate rear plate are made of steel; the four spring plate front plates on the side of the box body are arranged in a staggered manner with the grouting material test block and are sequentially overlapped to ensure that the four spring plate front plates on the side just wrap the grouting material test block, apply axial load to the grouting material test block and play a role in restricting lateral freedom; the width of the spring plate front plate is greater than the width of the grouting material test block, and the intersection point of the lightweight spring and the spring plate front plate is located at the quarter point of the two diagonals of the side of the grouting material test block close to the square endpoints.

5. The long-term durability performance test device for grouting materials under the action of a simulated complex coupling environment according to claim 1, characterized in that The air inlet and the air outlet are respectively arranged at the upper and lower 1 / 5 positions on the side of the box body.

6. A method for performing a load-dry and wet cycle durability test using the device according to any one of claims 1-5, characterized in that The method includes the following steps: Step 1: Install the spring plate and preset the acting load; Step 2: Open the upper water injection port or open the upper water injection port and the lower water outlet, close the valves of the anti-seepage test water injection port, the air inlet, and the air outlet, start the hydraulic pump, and inject water into the box body to complete the humidification process; Step 3: Open the air inlet and the air outlet, start the hot air pump, close the valves of the upper water injection port, the lower water outlet, and the anti-seepage test water injection port, and complete the drying process; Step 4: Repeat the processes of Step 2 and Step 3 to complete the wet-dry cycle test.

7. A method for performing an anti-seepage test using the device according to any one of claims 1-5, characterized in that The method includes the following steps: Step 1: Install the spring plate and preset the acting load; Step 2: Open the anti-seepage test water injection port, inject pressurized water, and observe the water seepage condition at the top of the grouting material test block through the observation window.

8. A method for performing a corrosion durability test using the device according to any one of claims 1-5, characterized in that The method includes the following steps: Step 1: Open the upper water injection port and inject the corrosive solution through the hydraulic pump; Step 2: When the water injection depth exceeds the height of the grouting material specimen, stop injecting the corrosive solution into the box body, close the upper water injection port, and let it stand for the time specified in the test plan.

9. A method for conducting a hydrostatic durability test using the device according to any one of claims 1-5, characterized in that The method includes the following steps: Step 1: Install a spring plate, preset the acting load, and restrict the lateral degrees of freedom of the grouting material specimen; Step 2: Fill the box body with water before sealing the cover plate; Step 3: Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the box through the pressure gauge.

10. A method for performing a load - water pressure durability test using the device according to any one of claims 1 - 5, characterized in that The method includes the following steps: Step 1: Install a spring plate and apply a unidirectional / bidirectional axial load to the grouting material specimen; Step 2: Fill the box body with water before sealing the cover plate; Step 3: Open the upper water injection port, start the hydraulic pump, and adjust the water pressure in the box through the pressure gauge.

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