Tensile test device for intergranular microbial cementation

Abstract

The utility model discloses a tensile test device for intergranular microorganism cementation, belongs to the technical field of mechanical test of microorganism reinforced rock soil, and aims to solve the technical problems that a traditional rock soil test instrument in the prior art is large in size, a sensor is insufficient in precision, the self-vibration during machine operation is relatively large, and the test efficiency is low. And therefore, the technical problem that the cattle-to-millicattle-level tensile force cannot be accurately measured can be solved. The tensile loading frame comprises a tensile loading frame body, and the tensile loading frame body comprises a host, a loading end and a plurality of stand columns; cross beams are arranged among the plurality of stand columns; the tension measuring mechanism comprises an adapter; and the clamp mechanism is used for fixing the microorganism cementation sample. The device can be better used for completing a tensile test of intergranular microbial cementation, and is low in operation noise, high in measurement precision and convenient to disassemble and assemble.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical testing of microbial reinforcement of rock and soil, in particular to a tensile testing device for intergranular microbial cementation. Background Art

[0002] In geotechnical engineering, loose rock and soil masses often need to be reinforced with cementitious materials to meet engineering requirements, increasing their strength and durability. Cement is the primary cementitious material used for reinforcement in traditional civil engineering, but its production is energy-intensive, and its large-scale use pollutes the environment and disrupts ecological balance. Emerging microbial reinforcement technology utilizes the metabolic products of bacteria (calcium carbonate crystals) in natural rock and soil to reinforce loose rock and soil masses, thereby improving and enhancing their performance. The reinforcement process is low-energy, low-pollution, and minimally disturbs the environment, making it a new, green and environmentally friendly reinforcement technology.

[0003] The forces acting on reinforced rock and soil in actual engineering projects are complex, and tensile failure of the reinforced rock and soil may occur. Therefore, understanding the tensile properties of cemented rock and soil is an important indicator for accurately assessing the stability and safety of engineering structures. Relevant experiments have been conducted in the laboratory to study the tensile mechanical properties of microbially reinforced rock and soil, but these experiments are mainly unit tests at the macroscale. Tensile tests on microbial cementation at the particle scale are still rare, mainly because the tensile strength of microbial cementation at the particle scale is often in the Newton to millinewton range, requiring high-precision force sensors and minimal machine noise interference to ensure measurement accuracy.

[0004] However, traditional geotechnical testing instruments are large in size, have insufficient sensor accuracy, and have large self-vibrations during machine operation, which affect measurement accuracy and make it impossible to accurately measure tensile forces at the Newton to millinewton level.

[0005] Therefore, there is an urgent need for a testing device that can perform tensile tests on microbial cemented specimens. Utility Model Content

[0006] The purpose of this utility model is to provide a tensile testing device for intergranular microbial cementation, so as to solve the technical problems in the prior art that traditional geotechnical testing instruments are large in size, have insufficient sensor accuracy, and have large self-vibration during machine operation, which affects the measurement accuracy and makes it impossible to accurately measure tensile forces at the Newton to millinewton level.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] The utility model provides a tensile testing device for intergranular microbial cementation, comprising:

[0009] A stretching loading frame body, comprising a main frame, loading ends respectively provided on the main frame, and a plurality of columns; a crossbeam is provided between the plurality of columns;

[0010] A tension measuring mechanism, the tension measuring mechanism comprising an adapter; the adapter is connected to the crossbeam;

[0011] A clamp mechanism is used to fix the microbial cementation sample, and the upper end of the clamp mechanism is connected to the tension measuring mechanism, and the lower end of the clamp mechanism is connected to the loading end.

[0012] The utility model fixes the microbial cementation sample on the clamp structure through epoxy resin, and the loading end of the tensile loading frame body moves downward at a uniform speed, thereby completing the tensile test of inter-particle microbial cementation. The internal displacement counter at the loading end of the device and the tensile sensor of the tensile measurement mechanism will record the changes in force and displacement during the entire tensile process, thereby quickly and effectively obtaining the tensile failure mechanical data of inter-particle microbial cementation, providing convenient equipment support for studying the tensile mechanical properties of particle-scale microbial cementation.

[0013] Optionally or preferably, the tension measuring mechanism further includes a tension sensor and a connecting flange; the adapter, the tension sensor and the connecting flange are connected in sequence.

[0014] Optionally or preferably, the clamp mechanism includes a flange disc, a fixing component, a lower end clamp and an upper end clamp; the flange disc is connected to the loading end; the upper end clamp is connected to the connecting flange; and a microbial cementation sample is arranged between the upper end clamp and the lower end clamp.

[0015] Optionally or preferably, it further comprises a specimen vertical straightening mechanism;

[0016] The sample vertical straightening mechanism comprises a straightening mold and a laser leveler; the straightening mold is arranged on the lower end fixture and is used to straighten the microbial cementation sample.

[0017] Optionally or preferably, the fixing component includes a first connecting portion and a second connecting portion;

[0018] The connecting portion 1 is in the shape of a rectangular parallelepiped as a whole, and a positioning hole is opened on the upper portion of the connecting portion 1, and the lower end clamp is connected to the fixing component through the positioning hole;

[0019] The second connecting portion is cylindrical in shape as a whole, and the lower end of the second connecting portion is fixedly connected to the flange disc.

[0020] Optionally or preferably, an operation interface is provided on the host; the operation interface includes a display screen and a control keyboard.

[0021] Optionally or preferably, the number of the columns provided is two;

[0022] The crossbeam is slidably connected between the two upright posts; both ends of the crossbeam are fixed to the upright posts via fixing nuts.

[0023] Optionally or preferably, the tension sensor is a high-precision tension sensor.

[0024] Based on the above technical solution, the present invention can at least produce the following technical effects:

[0025] The utility model provides a tensile testing device for intergranular microbial cementation, which can accurately measure the tensile resistance of particle-scale microbial cementation by being equipped with a high-precision tensile measuring mechanism; at the same time, different types of tensile sensors can be replaced according to the actual measurement range and accuracy requirements, thereby realizing multi-range measurement; at the same time, the device completes the tensile test of intergranular microbial cementation by uniformly moving the loading end in the main body of the tensile loading frame downward, and has low operating noise and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall structure of the tensile testing device for intergranular microbial cementation of the present invention;

[0027] Figure 2 This is a structural schematic diagram of the main body of the tensile loading frame in the tensile testing device for intergranular microbial cementation of the present invention;

[0028] Figure 3 This is a structural diagram of a tension measuring mechanism in a tensile testing device for intergranular microbial cementation according to the present invention;

[0029] Figure 4 This is a schematic structural diagram of the adapter in the tensile testing device for intergranular microbial cementation of the present invention;

[0030] Figure 5 This is a structural diagram of the connecting flange in the tensile test device for intergranular microbial cementation of the present invention;

[0031] Figure 6 This is a front structural diagram of the clamp mechanism in the tensile test device for intergranular microbial cementation of the present invention;

[0032] Figure 7 This is a schematic diagram of the back structure of the clamp mechanism in the tensile test device for intergranular microbial cementation of the present invention;

[0033] Figure 8 This is a schematic structural diagram of the flange disc in the tensile test device for intergranular microbial cementation of the present invention;

[0034] Figure 9 This is a schematic structural diagram of the fixed components in the tensile testing device for intergranular microbial cementation of the present invention;

[0035] Figure 10 This is a schematic structural diagram of the lower end fixture of the tensile testing device for intergranular microbial cementation of the present invention;

[0036] Figure 11 This is a schematic structural diagram of the upper end fixture of the tensile test device for intergranular microbial cementation of the present invention;

[0037] Figure 12 The utility model is a structural schematic diagram of a sample vertical righting mechanism in a tensile test device for intergranular microbial cementation.

[0038] In the figure: 10. Tensile loading frame body; 11. Main machine; 12. Loading end; 13. Column; 14. Beam; 15. Operation interface; 16. Fixing nut; 20. Tension measuring mechanism; 21. Adapter; 22. Tension sensor; 23. Connecting flange; 30. Clamp mechanism; 31. Flange disc; 32. Fixing component; 321. Connection part 1; 322. Connection part 2; 33. Lower end clamp; 34. Upper end clamp; 40. Microbial cementation specimen; 50. Specimen vertical straightening mechanism; 51. Straightening mold; 52. Laser level. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0040] Example

[0041] See also Figures 1 to 12 A tensile testing device for intergranular microbial cementation includes a tensile loading frame body 10 and a tensile force measuring mechanism 20 and a clamping mechanism 30 arranged on the tensile loading frame body 10.

[0042] In this embodiment, the tensile loading frame body 10 includes a main unit 11, two parallel columns 13 are provided at the upper end of the main unit 11, and a crossbeam 14 is provided between the two columns 13 via a fixing nut 16; the position of the crossbeam 14 on the columns 13 can be adjusted by the fixing nut 16; a circular hole is provided in the middle of the crossbeam 14, and the tension measuring mechanism 20 is connected to the tensile loading frame body 10 through the circular hole.

[0043] The upper end surface of the main machine 11 is also provided with a loading end 12, which is provided with multiple threaded holes. The clamp mechanism 30 is fixed to the loading end 12 by bolts. During the actual working process, the loading end 12 moves downward at a uniform speed, thereby completing the tensile test of intergranular microbial cementation.

[0044] Specifically, the tension measuring mechanism 20 includes an adapter 21, a tension sensor 22 and a connecting flange 23 connected in sequence; wherein the tension measuring mechanism 20 is threadedly connected to the beam 14 through the adapter 21, and the adapter 21 can be made of stainless steel.

[0045] In this embodiment, the above-mentioned tension sensor 22 is a high-precision tension sensor 22, which can be used to measure tension changes at the millinewton level, and its measurement range can be 5N; it can be understood that in this embodiment, the tension sensor 22 can be replaced with different models of tension sensors according to the actual measurement range and accuracy requirements, thereby realizing multi-range measurement.

[0046] Furthermore, a bolt hole is provided at the lower end of the connecting flange 23 , and the clamp mechanism 30 is connected to the tension measuring mechanism 20 through the bolt hole.

[0047] In this embodiment, the clamp mechanism 30 is used to fix the microbial cementation sample 40, which includes a flange disc 31, a fixing part 32, a lower end clamp 33 and an upper end clamp 34; the flange disc 31 is connected to the loading end 12; the upper end clamp 34 is connected to the connecting flange 23; the microbial cementation sample 40 is arranged between the upper end clamp 34 and the lower end clamp 33.

[0048] The flange disc 31 is made of stainless steel and has a plurality of threaded holes on its bottom. The flange disc 31 is connected to the loading end 12 of the tensile loading frame body 10 through the plurality of threaded holes.

[0049] In this embodiment, the above-mentioned fixing component 32 includes a rectangular connecting portion 1 321 and a cylindrical connecting portion 2 322; a positioning hole is provided on the connecting portion 1 321, and the lower end clamp 33 is connected to the fixing component 32 through the positioning hole; the lower end of the connecting portion 2 322 is fixedly connected to the flange disc 13.

[0050] In this embodiment, the lower clamp 33 is entirely made of stainless steel, and the upper clamp 34 is entirely made of high-strength PEAK material.

[0051] In order to ensure that the microbial cementation sample 40 can be well fixed between the upper clamp 34 and the lower clamp 33, in this embodiment, a vertical straightening mechanism 50 is also provided, which includes a straightening mold 51 and a laser level 52; the straightening mold 51 is arranged on the lower clamp 33. It can be understood that the straightening mold 51 has corresponding calibration surfaces, so that when the microbial cementation sample 40 abuts against the various calibration surfaces of the straightening mold 51, the microbial cementation sample 40 can be straightened and fixed.

[0052] In order to facilitate the tensile test operation and intuitively obtain experimental data, in this embodiment, the host 11 is provided with an operation interface 15, which includes a display screen and a control keyboard.

[0053] During the actual test, the particle diameters of the microbial cementation specimens 40 were 2 mm, 3 mm, and 4 mm, respectively. The tensile force measuring mechanism 20 and the clamp mechanism 30 were connected to the tensile loading frame body 10, respectively. Then, the microbial cementation specimens 40 (hereinafter referred to as specimens) were obtained, and the straightening mold 51 was placed on the lower end clamp 33 of the tensile clamp structure 30. A laser level 52 was placed in each vertical direction of the plane, and the specimen was placed on the lower end clamp 33. The lower end of the specimen was fixed with epoxy resin. During the curing period, the vertical laser on the straightening mold was referred to and the specimen was adjusted to be consistent with the axial loading direction until the specimen was completely fixed on the lower end clamp 33. The loading end 12 of the loading frame is then adjusted so that the upper end of the sample is close to the upper clamp 34 of the tensile fixture structure 30. Finally, the upper end of the particle sample is fixed to the upper clamp 34 of the tensile fixture structure 30 using epoxy resin. The epoxy resin is allowed to fully cure. The loading mode and loading speed are set on the main machine's operation interface 15, and the loading end 12 is controlled to move downward at a constant speed of 0.2 mm / s. During the tensile process, a high-definition camera is placed directly in front of the particle sample to record the tensile failure process of the microbial bond between the particles. Loading is stopped after the intergranular bond is destroyed.

[0054] After the test is complete, the upper clamp 34 of the tensile fixture mechanism 30 is rotated and removed. The epoxy resin on the upper clamp 34 is then removed using a debonding agent, and the upper portion of the failed specimen is collected and stored. Simultaneously, the bolts on the lower clamp 33 are rotated and removed. The epoxy resin on the lower clamp 33 is also removed using a debonding agent, and the lower portion of the failed specimen is collected and stored. After the epoxy resin on the upper and lower clamps 34 and 33 is completely removed, they are reinstalled. The position of the loading end 12 is adjusted, and microbial-cemented specimens 40 of varying particle sizes are secured using epoxy resin. The next intergranular microbial cementation tensile test is then conducted.

[0055] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tensile testing device for intergranular microbial cementation, characterized in that: include: A stretching loading frame body (10), comprising a main body (11), loading ends (12) and a plurality of columns (13) respectively arranged on the main body (11); a crossbeam (14) is arranged between the plurality of columns (13); A tension measuring mechanism (20), the tension measuring mechanism (20) comprising an adapter (21); the adapter (21) is connected to the crossbeam (14); A clamp mechanism (30) is used to fix the microbial cementation sample (40), and the upper end of the clamp mechanism (30) is connected to the tension measuring mechanism (20), and the lower end of the clamp mechanism (30) is connected to the loading end (12).

2. The tensile testing device for intergranular microbial cementation according to claim 1, characterized in that: The tension measuring mechanism (20) further comprises a tension sensor (22) and a connecting flange (23); the adapter (21), the tension sensor (22) and the connecting flange (23) are connected in sequence.

3. The tensile testing device for intergranular microbial cementation according to claim 2, characterized in that: The clamp mechanism (30) includes a flange disc (31), a fixing component (32), a lower end clamp (33) and an upper end clamp (34); the flange disc (31) is connected to the loading end (12); the upper end clamp (34) is connected to the connecting flange (23); a microbial cementation sample (40) is arranged between the upper end clamp (34) and the lower end clamp (33).

4. The tensile testing device for intergranular microbial cementation according to claim 3, characterized in that: Also included is a specimen vertical straightening mechanism (50); The sample vertical straightening mechanism (50) includes a straightening mold (51) and a laser level (52); the straightening mold (51) is arranged on the lower end clamp (33) and is used to straighten the microbial cementation sample (40).

5. The tensile testing device for intergranular microbial cementation according to claim 3, characterized in that: The fixing component (32) includes a first connecting portion (321) and a second connecting portion (322); The connecting portion 1 (321) is in the shape of a rectangular parallelepiped as a whole. A positioning hole is provided on the upper portion of the connecting portion 1 (321). The lower end clamp (33) is connected to the fixing component (32) through the positioning hole. The second connecting portion (322) is cylindrical in shape as a whole, and the lower end of the second connecting portion (322) is fixedly connected to the flange disc (31).

6. The tensile testing device for intergranular microbial cementation according to claim 1, characterized in that: The host (11) is provided with an operation interface (15); the operation interface (15) includes a display screen and a control keyboard.

7. The tensile testing device for intergranular microbial cementation according to claim 1, characterized in that: The number of the columns (13) is two; The crossbeam (14) is slidably connected between the two upright posts (13); both ends of the crossbeam (14) are fixed to the upright posts (13) via fixing nuts (16).

8. The tensile testing device for intergranular microbial cementation according to claim 2, characterized in that: The tension sensor (22) is a high-precision tension sensor.

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