A temperature-controlled microbial combined fiber-reinforced solidification triaxial sand sample preparation device

Abstract

This utility model relates to the field of experimental instrument technology, specifically to a temperature-controlled microbial combined fiber-reinforced triaxial sand sample solidification device, which can improve the accuracy of test results and solidification effect. It includes a sample preparation mold, a support platform, a container, and a temperature control chamber. The support platform, container, and sample preparation mold are all placed inside the temperature control chamber. The temperature control chamber also includes a peristaltic pump, a temperature sensor, and a ventilation system. The peristaltic pump is connected to the container and the sample preparation mold via a transmission pipe. The sample preparation mold includes an upper base, a middle sleeve, and a lower base. The upper and lower bases have identical structures. The lower base has a liquid channel, and its bottom has a threaded connector communicating with the liquid channel. The upper and lower bases are arranged facing each other and are respectively connected to the top and bottom of the middle sleeve.

Description

Technical Field

[0001] This utility model relates to the field of experimental instrument technology, specifically a temperature-controlled microbial combined fiber-reinforced solidification triaxial sand sample device. Background Technology

[0002] Microbial-induced calcium carbonate precipitation (MICP) technology has attracted widespread attention due to its advantages such as being green, harmless, energy-saving, environmentally friendly, and causing minimal disturbance. MICP technology generates calcium carbonate through microbial mineralization reactions, cementing loose sand particles into a cohesive whole, effectively improving the strength, stiffness, and seismic performance of the sand. Existing studies have shown that while the strength and other mechanical properties of sand solidified by microorganisms are improved, its toughness is significantly reduced, exhibiting obvious brittle failure characteristics. Therefore, it is necessary to conduct experiments on incorporating fiber reinforcement into sand to improve the toughness of the samples.

[0003] Existing microbial solidification sand testing devices often produce samples with poor homogeneity, leading to significant differences in test results and unclear patterns. Furthermore, the optimal temperature for microbial solidification of sand is 25℃, and most experiments do not consider the influence of ambient temperature on the solidification process. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a temperature-controlled microbial combined with fiber-reinforced triaxial sand sample preparation device, which can improve the accuracy of test results and the curing effect.

[0005] The technical solution is as follows: A temperature-controlled microbial combined fiber-reinforced solidification triaxial sand sample preparation device, characterized in that it includes a sample preparation mold, a support platform, a container, and a temperature control chamber. The support platform, container, and sample preparation mold are all placed inside the temperature control chamber. The temperature control chamber is also equipped with a peristaltic pump, a temperature sensor, and a ventilation system. The peristaltic pump is connected to the container and the sample preparation mold respectively through a transmission pipe. The sample preparation mold includes an upper base, a middle sleeve, and a lower base. The upper base and the lower base have the same structure. A liquid channel is opened in the lower base, and a threaded joint communicating with the liquid channel is provided at the bottom of the lower base. The upper base and the lower base are arranged facing each other and are respectively connected to the top and bottom of the middle sleeve.

[0006] Its further feature is that the lower base is divided into three layers: the upper first layer is a small cylinder with a diameter not greater than the inner diameter of the middle sleeve; the middle second layer is a large cylinder with a diameter consistent with the outer diameter of the middle sleeve; and the lower third layer is square. Both the upper first layer of the lower base and the lower first layer of the upper base are provided with perforated thin plates, and the opening diameter of the perforated thin plates is 2mm. The intermediate sleeve is made of two semi-circular thin plates spliced ​​together, and the upper and lower parts of the intermediate sleeve are both tightened with iron hoops.

[0007] With this invention, the upper and lower bases of the sample preparation mold have the same structure, so they can be inverted, thereby achieving the effect of uniformly reinforcing the sample. Furthermore, the temperature sensor of the temperature control chamber can monitor the temperature inside the chamber, and the air control system blows in hot or cold air to keep the temperature inside the temperature control chamber at a suitable temperature of 25°C, reducing the influence of ambient temperature on the degree of sample reinforcement. In addition, a perforated thin plate is set to prevent the loss of fibers with a minimum length of 3mm used in the laboratory, which can ensure the fiber reinforcement effect after curing and improve the mechanical properties of the cured sand. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the sample preparation mold structure; Figure 3 This is a schematic diagram of a perforated thin plate structure. Figure 4 This is a schematic diagram of the foundation structure; Figure 5 This is a schematic diagram of the temperature control box. Detailed Implementation

[0009] See Figures 1 to 5 As shown, a temperature-controlled microbial combined fiber-reinforced triaxial sand sample preparation device includes a sample preparation mold 1, a support platform 2, a reaction liquid container 3, and a temperature control chamber 4. The support platform 2, the reaction liquid container 3, and the sample preparation mold 1 are all placed inside the temperature control chamber 4. The temperature control chamber 4 is also equipped with a peristaltic pump 5, a temperature sensor 6, and a ventilation control system 7. To facilitate monitoring the temperature inside the temperature control chamber 4, a temperature display screen 8 is installed outside the temperature control chamber 4. The output mode of the ventilation control system 7 is selected based on the temperature display screen 8. The ventilation control system 7 mainly includes a refrigeration compressor and a hot air blower. If the temperature is lower than the set temperature of 25°C, the hot air blower introduces hot air into the chamber to raise the temperature to 25°C; if the temperature is higher than the set temperature of 25°C, the refrigeration compressor introduces cold air into the chamber to lower the temperature to 25°C. The above temperature control method is the existing conventional constant temperature chamber temperature control.

[0010] The peristaltic pump 5 is connected to the container 3 and the sample preparation mold 1 via the transfer pipe 9. The reaction liquid is placed in the reaction liquid container 3. The sample preparation mold 1 includes an upper base 10, an intermediate sleeve 11, and a lower base 12. The upper base 10 and the lower base 12 have the same structure. The structure of the lower base is described below: The lower base 12 has a liquid channel 13, and the bottom of the lower base 12 is provided with a threaded connector 14 that connects to the liquid channel 13. The upper base 10 and the lower base 12 are arranged facing each other and are respectively connected to the top and bottom of the intermediate sleeve 11. The intermediate sleeve 11 is made of two semi-circular thin plates spliced ​​together, and the upper and lower parts of the intermediate sleeve are tightened by iron hoops. The sample preparation mold 1 can both meet the requirements of uniform sample preparation and convenient sample disassembly.

[0011] The lower base 12 is divided into three layers. The upper first layer is a small cylinder with a height of 10mm and a diameter of 49mm, which is slightly smaller than the inner diameter of the middle sleeve 11 (50mm). It can be inserted into the middle sleeve 11 for assembly. The middle second layer is a large cylinder with a height of 15mm and a diameter of 60mm, which is the same as the outer diameter of the middle sleeve 11. Iron hoops can be used to tighten this layer with the middle sleeve, thereby fixing the sand sample and preventing the solution from seeping out of the device during reinforcement. The lower third layer is square with a height of 30mm and a side length of 80mm, which allows the mold to be placed horizontally more stably.

[0012] The platform 2 has a side length of 160 mm and a height of 80 mm. A circular hole with a diameter of 40 mm is opened in the center of the platform so that the peristaltic tube 15 can pass through the platform 2 and discharge the waste liquid into the waste liquid container 16. The waste liquid container 16 is a 250 ml wide-mouth conical bottle.

[0013] Both the upper first layer of the lower base 12 and the lower first layer of the upper base 10 are provided with perforated thin plates 17. The perforated thin plates 17 have an opening diameter of 2 mm, which allows bacterial liquid and reaction liquid to seep out; while the minimum length of the fiber used in the laboratory is 3 mm, so the fiber cannot be lost.

[0014] The usage process is as follows: Step 1: Lay gauze on the lower base 12 of the device to ensure that fine sand particles are not washed away by liquid during the reinforcement process. Place two perforated thin plates 17 in the upper base 10 and the lower base 12 respectively, and then assemble the intermediate sleeve 11 and insert it into the lower base 12. Calculate the required mass of dry sand based on the relative density and volume of the sample, divide it into 4 equal parts, and slowly fill the calcareous sand into the sample preparation mold 1 using the sand rain method. Since the lower sand will be compacted during the vibration compaction of the upper sample, in order to make the prepared sample more uniform, the target height of each layer decreases from bottom to top. After each layer of sand is compacted, the surface of the soil layer is roughened before the upper layer of sand is filled in. After the sample is filled, lay gauze on top, insert the upper base 10 into the intermediate sleeve 11, turn the rubber mold out, and then tighten the mold with iron hoops to ensure the mold's airtightness. Place the device on the support platform 2.

[0015] Step 2: Attach the transfer tube 9 of the peristaltic pump 5 to the upper threaded connector 14 of the upper base 10, and connect the lower threaded connector 14 of the lower base 12 to the peristaltic tube 15, inserting it into the waste liquid container 16. The effective components in the reaction solution are urea (concentration 1 mol / L) and calcium chloride (concentration 1 mol / L) in a molar ratio of 1:1. First, inject 1.2 times the pore volume of bacterial solution, with the peristaltic pump 5 injecting at a rate of 3 min / L. After standing for 6 hours, open the bottom drainage channel of the peristaltic tube 15 and drain the bacterial solution using gravity. Then, inject another 1.2 times the pore volume of the reaction solution of urea and calcium chloride (concentration 0.5 mol / L), with the peristaltic pump 5 injecting at a rate of 3 min / L. After standing for 12 hours, open the bottom peristaltic tube 15 and drain the waste liquid. A total of four injection cycles are performed.

[0016] Step 3: After four rounds of infusion, turn off the power to the temperature control chamber 4. Use a peristaltic pump 5 to pump 300 ml of deionized water into the sample twice at a rate of 3 ml / min to flush out any remaining waste liquid from the sample pores and ensure that the sample removed after disassembly is free of waste liquid. Remove the upper base 10, remove one perforated thin plate 17, and remove the other plate along with the sample to complete the disassembly.

Claims

1. A temperature-controlled microbial combined with fiber-reinforced solidification triaxial sand sample preparation device, characterized in that, It includes a sample preparation mold, a support platform, a container, and a temperature control chamber. The support platform, container, and sample preparation mold are all placed inside the temperature control chamber. The temperature control chamber is also equipped with a peristaltic pump, a temperature sensor, and a ventilation system. The peristaltic pump is connected to the container and the sample preparation mold through a transmission pipe. The sample preparation mold includes an upper base, a middle sleeve, and a lower base. The upper base and the lower base have the same structure. The lower base has a liquid channel and a threaded joint connecting the liquid channel is provided at the bottom of the lower base. The upper base and the lower base are arranged facing each other and are respectively connected to the top and bottom of the middle sleeve.

2. The temperature-controlled microbial combined fiber-reinforced solidification triaxial sand sample preparation device according to claim 1, characterized in that, The lower base is divided into three layers. The upper first layer is a small cylinder with a diameter no greater than the inner diameter of the middle sleeve. The middle second layer is a large cylinder with a diameter consistent with the outer diameter of the middle sleeve. The lower third layer is square.

3. The temperature-controlled microbial combined fiber-reinforced solidification triaxial sand sample preparation device according to claim 1, characterized in that, Both the upper first layer of the lower base and the lower first layer of the upper base are provided with perforated thin plates, and the opening diameter of the perforated thin plates is 2mm.

4. The temperature-controlled microbial combined with fiber-reinforced solidification triaxial sand sample preparation device according to claim 1, characterized in that, The intermediate sleeve is made of two semi-circular thin plates spliced ​​together, and the upper and lower parts of the intermediate sleeve are both tightened with iron hoops.

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