A cement-soil indoor test sample making device and method

Abstract

A cement soil indoor test sample preparation equipment and method, the equipment comprises: a stirring device and a compaction device; the stirring device comprises: a first base, a first machine body, a first shell, a thin-walled steel barrel, a fixed support assembly, a drill rod and a first controller; the first controller is connected with the stirring driving mechanism through an electric wire; the drill rod is driven by the stirring driving mechanism to extend into the thin-walled steel barrel to rotate and stir the cement soil and then slowly lift upwards to leave the cement soil; the compaction device comprises: a second base, a second machine body, a second shell, a mold, a large piston, a piston barrel and a second controller; the second controller is connected with the piston driving mechanism through an electric wire; the piston driving mechanism drives the large piston in the piston barrel to move up and down to perform a compaction action on the cement soil in the mold. The present application is convenient to operate, has good test effect and high cement soil sample qualification rate.

Description

Technical Field

[0001] This invention belongs to the technical field of building materials, specifically referring to a device and method for preparing indoor test specimens for cement-soil. Background Technology

[0002] Soft soil refers to a general term for a type of soil characterized by high natural water content, large natural void ratio, high compressibility, and very low shear strength and natural bearing capacity. In natural soil masses, it mainly exhibits a soft plastic to fluid plastic state, characterized primarily by low shear strength, high sensitivity, and poor permeability. The unique engineering properties of soft soil bring many problems to foundation engineering construction. Cement-soil is commonly used in engineering to reinforce weak soil layers, and the strength of cement-soil obtained from laboratory test samples is an important reference indicator; therefore, the preparation of cement-soil test samples is particularly crucial.

[0003] National standards stipulate that a cylindrical specimen with a diameter of Ф50mm × 100mm is the standard size for unconfined compressive strength test specimens of cement-soil. Currently, the mixers commonly used for specimen preparation are mostly cement mortar mixers, which have large mortar pots and mixing blades, making it difficult to uniformly shape the cement-soil. Furthermore, there is no fixed compaction device, and compaction is mostly done manually. As a result, the density of the specimens produced varies greatly, which is not conducive to the test and leads to a low pass rate for the final cement-soil specimens. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device and method for preparing cement-soil indoor test specimens, which is easy to operate, has good test results, and a high pass rate for cement-soil specimens.

[0005] This invention is implemented as follows:

[0006] A cement-soil indoor test specimen preparation device includes: a mixing device and a compaction device;

[0007] The stirring device includes: a first base, a first body, a first outer shell, a thin-walled steel barrel, a fixed support assembly, a drill rod, and a first controller;

[0008] The first base has a groove in the middle for accommodating the thin-walled steel barrel, and the bottom of the thin-walled steel barrel is embedded in the groove; the thin-walled steel barrel is filled with cement soil, and its bottom is a removable screw cap.

[0009] The first outer shell is disposed above the thin-walled steel drum;

[0010] The bottom of the first body is connected to the first base, and the top of the first body is connected to the first outer shell;

[0011] One end of the fixed bracket assembly is fixedly connected to the first machine body, and the other end is used to fix the barrel body of the thin-walled steel barrel;

[0012] The first housing is equipped with a stirring drive mechanism, and the drill rod is connected below the stirring drive mechanism. The drill rod is equipped with a spiral blade.

[0013] The first controller is connected to the stirring drive mechanism via a wire;

[0014] Driven by the stirring mechanism, the drill rod extends into the thin-walled steel drum to rotate and stir the cement-soil before being slowly lifted upwards and removed from the cement-soil.

[0015] The compaction device includes: a second base, a second body, a second outer shell, a mold, a large piston, a piston barrel, and a second controller;

[0016] The mold is embedded in the middle of the second base;

[0017] The bottom of the second body is connected to the second base, and the top of the second body is connected to the second outer shell; a rotating buckle is provided in the middle of the second body, and its horizontal rotation line is level with the top of the mold provided on the second base;

[0018] The second housing contains a piston drive mechanism; the bottom of the second housing contains the piston barrel; the piston barrel is located directly above the mold; the piston barrel contains the large piston; the large piston is connected to the piston drive mechanism.

[0019] The second controller is connected to the piston drive mechanism via a wire;

[0020] The piston drive mechanism drives the large piston inside the piston barrel to move up and down, compacting the cement soil inside the mold.

[0021] Furthermore, the stirring drive mechanism includes: a first bidirectional rotary motor, a pulley, a steel wire, and a unidirectional rotary motor;

[0022] The first bidirectional rotary motor is connected to the unidirectional rotary motor via a pulley and a steel wire.

[0023] The unidirectional rotary motor is bolted to the top of the drill rod.

[0024] Furthermore, the fixed bracket assembly includes: a pair of fixed rods, a pair of L-shaped brackets, and a pair of tightening nuts;

[0025] One end of the L-shaped bracket is fixedly connected to one end of the fixing rod by the tightening nut, and the other end of the fixing rod is fixedly connected to the machine body; the other end of the L-shaped bracket is used to clamp the thin-walled steel drum.

[0026] Furthermore, the piston drive mechanism includes: a hydraulic pipe, a second bidirectional rotary motor, and a rotating rod mechanism;

[0027] The hydraulic pipe is U-shaped, with one end passing through the second housing and connected to the piston, and the other end connected to the rotating rod mechanism;

[0028] The lever mechanism includes: a small piston, two small cantilever arms, a pin, a ring, and a rotating arm;

[0029] One end of the small piston is provided with two small cantilever arms, which are inserted into the rotating arm; the other end of the small piston is connected to the end of the hydraulic pipe;

[0030] The rotating arm has an irregular cross-section and an internal ring. The ends of the two small cantilever arms are fixedly connected by a pin. The ring is fitted onto the pin.

[0031] One end of the rotating arm is fixedly connected to the second bidirectional rotating motor, and the other end is connected to the hydraulic pipe through the small piston. The hydraulic pipe is filled with hydraulic oil.

[0032] The second bidirectional rotary motor drives the rotating arm to rotate, and the rotating arm drives the small piston to move laterally. The small piston drives the large piston to move up and down through the hydraulic oil in the hydraulic pipe, thereby compacting the cement soil in the mold.

[0033] A method for preparing cement-soil indoor test specimens, utilizing the cement-soil indoor test specimen preparation equipment described above, includes the following steps:

[0034] Step S1: Prepare the mixing device, and weigh the soil sample, cement and water according to the pre-determined assumed density of cement-soil;

[0035] Step S2: Place the weighed material into the thin-walled steel drum, embed the thin-walled steel drum into the groove of the first base, and adjust the fixing bracket assembly until the thin-walled steel drum no longer shakes.

[0036] Step S3: Adjust the first controller, lower the drill rod to the appropriate position, and start the one-way rotary motor switch to begin stirring;

[0037] Step S4: After the drill rod has been stirred at the bottom for a certain period of time, adjust the first controller to make the drill rod slowly rise until it leaves the soil.

[0038] Step S5: Repeat step S4 until the sample is basically formed;

[0039] Step S6: Remove the thin-walled steel drum and take out the compaction device at the same time, and fix the mold in the groove of the second base;

[0040] Step S7: Move the rotating buckle, rotate the upper part of the second machine body to free up the space above the mold, remove the bottom screw cap of the thin-walled steel barrel to allow the sample to slide out by itself, calculate the height of the sample sliding out each time according to the predetermined number of compaction times, cut it with the blade and slowly put it into the mold, replace the bottom screw cap of the thin-walled steel barrel, rotate back to the second machine body, and adjust the second controller to lower the large piston by the required distance.

[0041] Step S8: Repeat step S7 until the sample is finally formed.

[0042] Furthermore, in step S7,

[0043] The average pressing distance per stroke can be calculated and set according to the following formula (1):

[0044]

[0045] In the formula, V1 is the volume of the mold (cm³). 3 V2 is the volume of the specimen formed in the thin-walled steel cylinder (cm³). 3 ); r is the inner diameter of the mold and the thin-walled steel barrel (mm), taken as 50mm; n is the designed number of pressing cycles; x is the pressing distance (mm) for each cycle.

[0046] The advantages of this invention are: the mixing device ensures that the cement-soil is mixed sufficiently and the compaction device compacts the cement-soil as much as possible, so that the prepared cement-soil sample is as close as possible to the cement-soil in the actual field project. The data of the cement-soil sample that has passed the unconfined compressive strength test and other tests can be applied to the actual project to obtain the best results. Attached Figure Description

[0047] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0048] Figure 1 This is a front view of the stirring device in this invention.

[0049] Figure 2 This is a side view of the stirring device in this invention.

[0050] Figure 3 This is a front view of the compaction device in this invention.

[0051] Figure 4 This is a side view of the compaction device in this invention.

[0052] Figure 5 This is a schematic diagram of the rotating rod mechanism of the compaction device in this invention.

[0053] Figure 6 This is a cross-sectional view of the rotating arm of the rotating rod mechanism of the compaction device in this invention.

[0054] Figure 7This is a schematic cross-sectional view of the rotating arm and two small cantilever arms of the compaction device in this invention.

[0055] Figure 8 This is a schematic diagram of the longitudinal section of the rotating arm and two small cantilever arms of the compaction device in this invention. Detailed Implementation

[0056] like Figures 1 to 8 As shown, a cement-soil indoor test specimen preparation device includes: a mixing device 100 and a compaction device 200;

[0057] The stirring device 100 includes: a first base 101, a first body 102, a first outer shell 103, a thin-walled steel barrel 104, a fixed support assembly 105, a drill rod 106, and a first controller 107.

[0058] The first base 101 has a groove in the middle for accommodating the thin-walled steel barrel 104, and the bottom of the thin-walled steel barrel 104 is embedded in the groove; the thin-walled steel barrel 104 is filled with cement soil, and its bottom is a removable screw cap.

[0059] The first outer shell 103 is disposed above the thin-walled steel barrel 104;

[0060] The bottom of the first body 102 is connected to the first base 101, and the top of the first body 102 is connected to the first outer shell 103;

[0061] One end of the fixed support assembly 105 is fixedly connected to the first machine body 101, and the other end is used to fix the body of the thin-walled steel drum 104; wherein, the fixed support assembly 105 includes: a pair of fixed rods 1051, an L-shaped bracket 1052, and a tightening nut 1053; one end of the L-shaped bracket 1052 is fixedly connected to one end of the fixed rod 1051 through the tightening nut 1053, and the other end of the fixed rod 1051 is fixedly connected to the machine body 102; the other end of the L-shaped bracket 1052 is used to clamp the thin-walled steel drum 104.

[0062] The first outer casing 103 is provided with a stirring drive mechanism 108, and the drill rod 106 is connected to the lower part of the stirring drive mechanism 108. The drill rod is provided with a spiral blade 1061.

[0063] The first controller 107 is connected to the stirring drive mechanism 108 via a wire; the stirring drive mechanism 108 includes: a first bidirectional rotary motor 1081, a pulley 1082, a steel wire 1083, and a unidirectional rotary motor 1084; the first bidirectional rotary motor 1081 is connected to the unidirectional rotary motor 1084 via the pulley 1082 and the steel wire 1083; the unidirectional rotary motor 1084 is bolted to the top of the drill rod 106.

[0064] Driven by the stirring drive mechanism 108, the drill rod 106 extends into the thin-walled steel drum 4 to rotate and stir the cement soil before being slowly lifted upwards and removed from the cement soil.

[0065] The compaction device 200 includes: a second base 201, a second body 202, a second outer shell 203, a mold 204, a large piston 205, a piston barrel 206, and a second controller 207.

[0066] The mold 204 is embedded in the middle of the second base 201;

[0067] The bottom of the second body 202 is connected to the second base 201, and the top of the second body 202 is connected to the second outer shell 203; a rotating buckle 2021 is provided in the middle of the second body 202, and its horizontal rotation line is level with the top of the mold 204 provided on the second base 201.

[0068] The second outer casing 203 is provided with a piston drive mechanism 208; the bottom of the second outer casing 203 is provided with the piston barrel 206; the piston barrel 206 is located directly above the mold 204; the piston barrel 206 is provided with the large piston 205; the large piston 205 is connected to the piston drive mechanism 208.

[0069] The second controller 207 is connected to the piston drive mechanism 208 via a wire;

[0070] The piston drive mechanism drives the large piston inside the piston barrel to move up and down, compacting the cement soil inside the mold.

[0071] The piston drive mechanism 208 includes: a hydraulic pipe 2081, a second bidirectional rotary motor 2082, and a rotating rod mechanism 2083; the hydraulic pipe 2081 is U-shaped, with one end passing through the second outer shell 203 and connected to the large piston 205, and the other end connected to the rotating rod mechanism 2083;

[0072] The lever mechanism 2083 includes: a small piston 20831, two small cantilever arms 20832, a pin 20835, a ring body 20833, and a rotating arm 20834.

[0073] One end of the small piston 20831 is provided with two small cantilever arms 20832, which are inserted into the rotating arm 20834; the other end of the small piston 20831 is connected to the end of the hydraulic pipe 2081.

[0074] The rotating arm 20834 has an irregular cross-section and an inner ring 20833. The ends of the two small cantilever arms 20832 are fixedly connected by a pin 20835. The ring 20833 is sleeved on the pin 20835.

[0075] One end of the rotating arm 20834 is fixedly connected to the second bidirectional rotating motor 2082, and the other end is connected to the hydraulic pipe 2081 through the small piston 20831. The hydraulic pipe 2081 is filled with hydraulic oil.

[0076] The second bidirectional rotary motor 2082 drives the rotating arm 20834 to rotate, and the rotating arm 20834 drives the small piston 20831 to move laterally. The small piston 20831 drives the large piston 205 to move up and down through the hydraulic oil in the hydraulic pipe 2081, thereby compacting the cement soil in the mold 204.

[0077] The present invention also provides a method for preparing cement-soil indoor test specimens, utilizing the cement-soil indoor test specimen preparation equipment described above. The method includes the following steps:

[0078] Step S1: Prepare mixing device 100, and weigh soil sample, cement and water according to the pre-determined assumed density of cement-soil;

[0079] Step S2: Place the weighed material into the thin-walled steel drum 104, embed the thin-walled steel drum 104 into the groove of the first base 101, and adjust the fixing bracket assembly 105 until the thin-walled steel drum 104 no longer shakes.

[0080] Step S3: Adjust the first controller 107, lower the drill rod 106 to the appropriate position, and start the one-way rotary motor switch 1084 to begin stirring;

[0081] Step S4: After the drill rod 106 has been stirred at the bottom for a certain period of time, adjust the first controller 107 to make the drill rod slowly rise until it leaves the soil.

[0082] Step S5: Repeat step S4 until the sample is basically formed;

[0083] Step S6: Remove the thin-walled steel drum 104 and at the same time take out the compaction device 200, and fix the mold 204 in the groove of the second base 201.

[0084] Step S7: Move the rotating buckle 2021, rotate the upper part of the second machine body 202 to free up the upper space of the mold 204, remove the bottom screw cap of the thin-walled steel barrel 104 to allow the sample to slide out by itself, calculate the height of the sample sliding out each time according to the predetermined number of compaction times, cut it with the blade and slowly put it into the mold 204, replace the bottom screw cap of the thin-walled steel barrel 104, turn back to the second machine body 202, and adjust the second controller 207 to lower the large piston 205 by the required distance;

[0085] The average pressing distance per stroke can be calculated and set according to the following formula (1):

[0086]

[0087] In the formula, V1 is the volume of the mold (cm³). 3 V2 is the volume of the specimen formed in the thin-walled steel cylinder (cm³). 3 ); r is the inner diameter of the mold and the thin-walled steel barrel (mm), taken as 50mm; n is the designed number of pressing cycles; x is the pressing distance (mm) for each cycle.

[0088] Step S8: Repeat step S7 until the sample is finally formed.

[0089] The present invention uses a mixing device 100 to ensure that the cement-soil is mixed sufficiently and a compaction device 200 to compact the cement-soil as much as possible, so that the prepared cement-soil sample is as close as possible to the cement-soil in the actual field project. The data of the cement-soil sample that has passed the unconfined compressive strength test and other tests can be applied to the actual project to obtain the best results.

[0090] The above embodiments and figures are not intended to limit the form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A device for preparing indoor test specimens for cement-soil experiments, characterized in that: include: Mixing and compaction devices; The stirring device includes: a first base, a first body, a first outer shell, a thin-walled steel barrel, a fixed support assembly, a drill rod, and a first controller; The first base has a groove in the middle for accommodating the thin-walled steel barrel, and the bottom of the thin-walled steel barrel is embedded in the groove; the thin-walled steel barrel is filled with cement soil, and its bottom is a removable screw cap. The first outer shell is disposed above the thin-walled steel drum; The bottom of the first body is connected to the first base, and the top of the first body is connected to the first outer shell; One end of the fixed bracket assembly is fixedly connected to the first machine body, and the other end is used to fix the barrel body of the thin-walled steel barrel; The first housing is equipped with a stirring drive mechanism, and the drill rod is connected below the stirring drive mechanism. The drill rod is equipped with a spiral blade. The first controller is connected to the stirring drive mechanism via a wire; Driven by the stirring mechanism, the drill rod extends into the thin-walled steel drum to rotate and stir the cement-soil before being slowly lifted upwards and removed from the cement-soil. The compaction device includes: a second base, a second body, a second outer shell, a mold, a large piston, a piston barrel, and a second controller; The mold is embedded in the middle of the second base; The bottom of the second body is connected to the second base, and the top of the second body is connected to the second outer shell; a rotating buckle is provided in the middle of the second body, and its horizontal rotation line is level with the top of the mold provided on the second base; The second housing contains a piston drive mechanism; the bottom of the second housing contains the piston barrel; the piston barrel is located directly above the mold; the piston barrel contains the large piston; the large piston is connected to the piston drive mechanism. The second controller is connected to the piston drive mechanism via a wire; The piston drive mechanism drives the large piston inside the piston barrel to move up and down, compacting the cement soil inside the mold.

2. The cement-soil indoor test specimen preparation equipment as described in claim 1, characterized in that: The stirring drive mechanism includes: a first bidirectional rotary motor, a pulley, a steel wire, and a unidirectional rotary motor; The first bidirectional rotary motor is connected to the unidirectional rotary motor via a pulley and a steel wire. The unidirectional rotary motor is bolted to the top of the drill rod.

3. The equipment for preparing cement-soil indoor test specimens as described in claim 1, characterized in that: The fixed bracket assembly includes: a pair of fixed rods, a pair of L-shaped brackets, and a pair of tightening nuts; One end of the L-shaped bracket is fixedly connected to one end of the fixing rod by the tightening nut, and the other end of the fixing rod is fixedly connected to the machine body; the other end of the L-shaped bracket is used to clamp the thin-walled steel drum.

4. The cement-soil indoor test specimen preparation equipment as described in claim 1, characterized in that: The piston drive mechanism includes: a hydraulic pipe, a second bidirectional rotary motor, and a rotating rod mechanism; The hydraulic pipe is U-shaped, with one end passing through the second housing and connected to the piston, and the other end connected to the rotating rod mechanism; The lever mechanism includes: a small piston, two small cantilever arms, a pin, a ring, and a rotating arm; One end of the small piston is provided with two small cantilever arms, which are inserted into the rotating arm; the other end of the small piston is connected to the end of the hydraulic pipe; The rotating arm has an irregular cross-section and an internal ring. The ends of the two small cantilever arms are fixedly connected by a pin. The ring is fitted onto the pin. One end of the rotating arm is fixedly connected to the second bidirectional rotating motor, and the other end is connected to the hydraulic pipe through the small piston. The hydraulic pipe is filled with hydraulic oil. The second bidirectional rotary motor drives the rotating arm to rotate, and the rotating arm drives the small piston to move laterally. The small piston drives the large piston to move up and down through the hydraulic oil in the hydraulic pipe, thereby compacting the cement soil in the mold.

5. A method for preparing indoor test specimens for cement-soil, characterized in that: Using the cement-soil indoor test specimen preparation equipment as described in any one of claims 1-4, the preparation method includes the following steps: Step S1: Prepare the mixing device, and weigh the soil sample, cement and water according to the pre-determined assumed density of cement-soil; Step S2: Place the weighed material into the thin-walled steel drum, embed the thin-walled steel drum into the groove of the first base, and adjust the fixing bracket assembly until the thin-walled steel drum no longer shakes. Step S3: Adjust the first controller, lower the drill rod to the appropriate position, and start the one-way rotary motor switch to begin stirring; Step S4: After the drill rod has been stirred at the bottom for a certain period of time, adjust the first controller to make the drill rod slowly rise until it leaves the soil. Step S5: Repeat step S4 until the sample is basically formed; Step S6: Remove the thin-walled steel drum and take out the compaction device at the same time, and fix the mold in the groove of the second base; Step S7: Move the rotating buckle, rotate the upper part of the second machine body to free up the space above the mold, remove the bottom screw cap of the thin-walled steel barrel to allow the sample to slide out by itself, calculate the height of the sample sliding out each time according to the predetermined number of compaction times, cut it with the blade and slowly put it into the mold, replace the bottom screw cap of the thin-walled steel barrel, rotate back to the second machine body, and adjust the second controller to lower the large piston by the required distance. Step S8: Repeat step S7 until the sample is finally formed.

6. The method for preparing cement-soil indoor test specimens as described in claim 5, characterized in that: In step S7 The average pressing distance per stroke can be calculated and set according to the following formula (1): In the formula, V1 is the volume of the mold (cm³). 3 V2 is the volume of the specimen formed in the thin-walled steel cylinder (cm³). 3 ); r is the inner diameter of the mold and the thin-walled steel barrel (mm), taken as 50mm; n is the designed number of pressing cycles; x is the pressing distance (mm) for each cycle.

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