Cement-based material pore negative pressure testing device

Abstract

The utility model discloses a cement-based material pore negative pressure testing device, and relates to the technical field of cement-based material performance detection. The device comprises a vertically arranged bearing tube, a porous ceramic probe vertically fixed at the lower port of the bearing tube, a pressure sensor connected to the outer wall of the upper part of the bearing tube, and a needle cylinder injector, the needle cylinder injector is vertically arranged above the bearing tube; the lower end part of the needle cylinder injector is connected with the upper port of the bearing tube through an exhaust valve; a supporting plate is horizontally arranged below the bearing pipe; a containing opening is formed in the upper surface of the supporting plate. The lower end of the bearing pipe can penetrate through the containing opening to extend to the position below the supporting plate. A lifting assembly is vertically arranged on the upper surface of the supporting plate. The lifting assembly is connected with the bearing pipe through a transmission frame. The cement-based material pore negative pressure testing device is reasonable in structural design and convenient to use, and the testing accuracy and the testing effect of the cement-based material pore negative pressure are effectively guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of cement-based material performance detection, in particular to a cement-based material pore negative pressure testing device. Background Art

[0002] Cement-based materials are building materials frequently used in the field of civil engineering, and the porosity of cement-based materials is an important technical parameter that determines the mechanical properties, transmission properties and durability of cement-based materials. In the prior art, when testing the negative pressure of the pores of cement-based materials, the connecting pipe and the ceramic head at the lower end of the connecting pipe are usually filled with water first, and then the ceramic head at the lower end of the connecting pipe is inserted into the newly mixed cement-based material. When the matrix potential of the dry cement-based material is lower than the pressure potential of the water in the connecting pipe, the cement-based material absorbs water into the connecting pipe through the ceramic head until it is balanced. The connecting pipe is sealed, and a vacuum or suction is generated in the connecting pipe. At this time, the pressure displayed by the pressure sensor on the connecting pipe is the negative pressure of the cement-based material. However, when injecting water into the connecting pipe and the ceramic head, the required requirements are sometimes not met. For example, the air in the connecting pipe or the ceramic head may not be exhausted cleanly, thus affecting the accuracy of the pore negative pressure test of the cement-based material; and, since the drying degree of the cement-based material is relatively slow, and the ceramic head is generally directly inserted into the cement-based material, the connecting pipe may fall under the interference of external factors (such as wind), thereby causing the contact effect between the ceramic head and the cement-based material to deteriorate, which has a certain impact on the pore negative pressure test effect of the cement-based material. Therefore, it is urgent to study a cement-based material pore negative pressure test device to solve the above problems. Utility Model Content

[0003] The utility model provides a cement-based material pore negative pressure testing device, the purpose of which is to solve the technical problems raised in the above background technology.

[0004] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0005] The utility model discloses a cement-based material pore negative pressure testing device, comprising a vertically arranged supporting tube, a porous ceramic probe vertically fixed at the lower port of the supporting tube, a pressure sensor connected to the outer wall of the upper part of the supporting tube, and a syringe injector; the syringe injector is vertically arranged above the supporting tube; the lower end of the syringe injector is connected to the upper port of the supporting tube through an exhaust valve; a supporting plate is horizontally arranged below the supporting tube; a receiving port coaxially arranged with the supporting tube is opened on the upper surface of the supporting plate; the lower end of the supporting tube can pass through the receiving port and extend to the lower part of the supporting plate; a lifting assembly is vertically installed on the upper surface of the supporting plate; the lifting assembly and the supporting tube are connected through a transmission frame.

[0006] As a preferred technical solution of the utility model, the upper outer wall of the supporting tube is radially connected with a bypass tube; the detection end of the pressure sensor is fixedly inserted in the bypass tube.

[0007] As a preferred technical solution of the utility model, the exhaust valve includes a connecting tube vertically fixed at the upper port of the supporting tube; the lower end of the syringe is fixedly inserted in the upper port of the connecting tube; a sealing column is vertically fixed in the connecting tube; a first through hole is vertically opened on the sealing column; a second through hole connected to the first through hole is horizontally opened on the circumferential side wall of the sealing column; an extension tube corresponding to the second through hole is radially connected to the outer wall of the connecting tube; a positioning column for blocking the first through hole is threadedly matched in the extension tube; one end of the positioning column can be slidably inserted in the second through hole.

[0008] As a preferred technical solution of the utility model, the lifting assembly includes a pair of mounting seats that are both vertically fixed on the upper surface of the support plate; a guide rod is vertically fixed on one of the mounting seats; a sliding sleeve is provided on the guide rod; a screw rod parallel to the guide rod is rotatably connected to the other mounting seat; a screw sleeve is threadedly matched on the screw rod; a lifting strip connected to the transmission frame is vertically fixed to the outer wall of the screw sleeve and the outer wall of the sliding sleeve; and scale lines are vertically provided on the outer wall of the guide rod.

[0009] As a preferred technical solution of the utility model, the transmission frame includes a pair of hoops which are arranged side by side from top to bottom on the outer periphery of the upper part of the supporting tube; the upper and lower ends of the lifting strip are respectively connected to the two hoops; the hoops include a pair of symmetrically arranged half-shaped hoops; the two half-shaped hoops are connected by a pair of bolt members; the upper and lower ends of the lifting strip are both provided with third through holes corresponding to the bolt members; the bolt members are inserted into the third through holes.

[0010] The utility model has the following beneficial effects:

[0011] The utility model connects the lifting component and the bearing tube through a transmission frame, and then places the support plate horizontally on the cement-based material, and then vertically inserts the porous ceramic probe into the cement-based material through the lifting component. In the process of slow drying of the cement-based material, when the matrix potential of the dry cement-based material is lower than the pressure potential of the water in the bearing tube, the cement-based material absorbs water to the bearing tube through the porous ceramic probe until balance is reached, and the bearing tube is sealed, and a vacuum degree or suction is generated in the bearing tube. At this time, the pressure detected by the pressure sensor on the bearing tube is the negative pressure of the cement-based material, thereby completing the test of the pore negative pressure of the cement-based material. Since the bearing tube is repeatedly evacuated by a syringe, it can be ensured that the air in the bearing tube and the porous ceramic probe is completely removed, and the accuracy of the pore negative pressure test of the cement-based material is effectively improved. At the same time, the bearing tube is supported by the support plate, and the lifting component is used to vertically insert the porous ceramic probe into the cement-based material, which can effectively avoid the problem of the bearing tube tipping over, and ensure the pore negative pressure test effect of the cement-based material.

[0012] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 The utility model is a structural schematic diagram of a cement-based material pore negative pressure testing device.

[0015] Figure 2 for Figure 1 The main view of the structure.

[0016] Figure 3 for Figure 1 Side view of the structure.

[0017] Figure 4 It is a schematic diagram of the structure of the connection between the carrier tube and the syringe of the utility model.

[0018] Figure 5 It is a schematic structural diagram of the exhaust valve of the utility model.

[0019] Figure 6 It is a structural schematic diagram of the connection tube of the utility model being arranged on the supporting tube.

[0020] Figure 7 It is a structural schematic diagram of the sealing column of the utility model.

[0021] Figure 8 It is a structural schematic diagram of the lifting assembly of the utility model.

[0022] Fig. 9 It is a schematic structural diagram of the connection between the lifting strip and the transmission frame of the utility model.

[0023] Fig.10 It is a structural schematic diagram of the lifting strip of the utility model.

[0024] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0025] 1-carrying tube, 2-porous ceramic probe, 3-pressure sensor, 4-syringe injector, 5-exhaust valve, 6-support plate, 7-lifting assembly, 8-transmission frame, 101-bypass tube, 501-connecting tube, 502-sealing column, 503-first through hole, 504-second through hole, 505-extension tube, 506-positioning column, 601-accommodating port, 701-mounting seat, 702-guide rod, 703-sliding sleeve, 704-screw rod, 705-screw sleeve, 706-lifting strip, 707-third through hole, 708-scale line, 801-semi-shaped hoop, 802-bolt. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] Embodiment 1:

[0028] See also Figure 1-Figure 4As shown, the utility model is a cement-based material pore negative pressure testing device, comprising a vertically arranged supporting tube 1, a porous ceramic probe 2 vertically fixed at the lower end of the supporting tube 1, a conventional pressure sensor 3 in the art, and a conventional syringe injector 4 in the art; the supporting tube 1 is a conventional plastic tube in the art; a bypass tube 101 is radially welded to the upper outer wall of the supporting tube 1; the inner cavity of the bypass tube 101 is connected to the inner cavity of the supporting tube 1; the detection end of the pressure sensor 3 is fixedly plugged into the bypass tube 101; the pressure sensor 3 is electrically connected to a conventional data acquisition system in the art; the data acquisition system includes a variable The present invention comprises a transmitter, an A / D converter connected to the transmitter, and a computer connected to the A / D converter; the porous ceramic probe 2 is a conventional component in this field; a syringe injector 4 is vertically arranged above the supporting tube 1; the lower end of the syringe injector 4 is connected to the upper end of the supporting tube 1 through an exhaust valve 5; a support plate 6 is horizontally arranged below the supporting tube 1; a receiving port 601 coaxially arranged with the supporting tube 1 is opened on the upper surface of the supporting plate 6; the lower end of the supporting tube 1 can pass through the receiving port 601 to extend to the bottom of the supporting plate 6; a lifting assembly 7 is vertically installed on the upper surface of the supporting plate 6; the lifting assembly 7 and the supporting tube 1 are connected through a transmission frame 8.Before use, 24 hours before the pore negative pressure test of cement-based materials, the porous ceramic probe 2 is first completely immersed in air-free water for pre-saturation (air-free water can be obtained by heating ordinary tap water to boiling, and continuing to heat for 30 minutes and then cooling), and then the lower end of the syringe 4 is connected to the upper port of the supporting tube 1 through the exhaust valve 5, and then the supporting tube 1 is evacuated using the syringe 4. Under the negative pressure of the syringe 4, moisture will pass through the porous ceramic probe 2 and enter the supporting tube 1. At the same time, the gas in the porous ceramic probe 2 will gradually overflow. By using the syringe 4 to repeatedly evacuate air until there is no bubble overflow from the porous ceramic probe 2, it means that the air in the supporting tube 1 and the porous ceramic probe 2 has been completely removed, and then the upper end of the supporting tube 1 is sealed by closing the exhaust valve 5, and the porous ceramic probe 2 continues to be immersed in water for standby use; when in use, the lifting assembly 7 is connected to the supporting tube 1 through the transmission frame 8, and then the support plate 6 is placed horizontally on the cement substrate The porous ceramic probe 2 is then vertically inserted into the cement-based material through the lifting component 7. During the slow drying process of the cement-based material, when the matrix potential of the dried cement-based material is lower than the pressure potential of the water in the supporting tube 1, the cement-based material absorbs water to the supporting tube 1 through the porous ceramic probe 2 until it is balanced. The supporting tube 1 is sealed, and a vacuum or suction is generated in the supporting tube 1. At this time, the pressure detected by the pressure sensor 3 on the supporting tube 1 is the negative pressure of the cement-based material, thereby completing the test of the pore negative pressure of the cement-based material. Since the syringe injector 4 is used to repeatedly evacuate the supporting tube 1, it can ensure that the air in the supporting tube 1 and the porous ceramic probe 2 is completely removed, and the accuracy of the pore negative pressure test of the cement-based material is effectively improved. At the same time, the supporting tube 1 is supported by the support plate 6, and the lifting component 7 is used to vertically insert the porous ceramic probe 2 into the cement-based material, which can effectively avoid the problem of the supporting tube 1 tipping over, thereby ensuring the pore negative pressure test effect of the cement-based material.

[0029] It should be noted that the porous ceramic probe 2 should be buried inside the cement-based material according to the following requirements, namely: 1) When used to determine the start time of initial maintenance, the porous ceramic probe 2 should be buried 5 mm away from the exposed surface of the cement-based material (concrete); 2) When used to determine the start time of mid-term and late maintenance, the porous ceramic probe 2 should be buried in the center of the cement-based material (concrete) casting body or more than 500 mm away from the exposed surface of the cement-based material (concrete); 3) For the same casting block, in order to reflect the differences in the development of pore negative pressure of cement-based materials (concrete) in different casting batches, the start and end batches of cement-based materials (concrete) should be tested for pore negative pressure, and the intermediate batches of cement-based materials (concrete) can be determined according to specific needs; 4) The data collection time interval should not exceed 1 minute, and the data reading time interval should not exceed 5 minutes when reading manually.

[0030] At the same time, it should be pointed out that: the test data of pressure sensor 3 minus the initial value is used to obtain the pore negative pressure of the cement-based material being tested, accurate to 1.0 kPa; the pore negative pressure development curve should be drawn with time (zero point from the beginning of water addition and stirring) as the horizontal axis and the pore negative pressure as the vertical axis. The pore negative pressure values ​​of the cement-based material at different times can be found according to the curve, and the corresponding time can also be queried according to the pore negative pressure value.

[0031] Among them Figure 5-Figure 7 As shown, the exhaust valve 5 includes a connecting tube 501 with a vertical thread fitted at the upper end of the supporting tube 1; the lower end of the syringe 4 is interference-fitted in the upper end of the connecting tube 501; a vertically arranged sealing column 502 is interference-fitted in the connecting tube 501; a first through hole 503 for connecting the syringe 4 with the supporting tube 1 is vertically opened on the sealing column 502; a second through hole 504 connected to the first through hole 503 is horizontally opened on the circumferential side wall of the sealing column 502; the diameter of the second through hole 504 is larger than the diameter of the first through hole 503; an extension tube 505 corresponding to the second through hole 504 is radially welded on the outer wall of the connecting tube 501; a positioning column 506 for blocking the first through hole 503 is internally threaded in the extension tube 505; one end of the positioning column 506 can be slidably inserted into the second through hole 504. When in use, the positioning column 506 is rotated to move one end of the positioning column 506 out of the second through hole 504, so that the first through hole 503 connects the syringe 4 with the supporting tube 1, thereby ensuring the air extraction effect of the syringe 4 on the supporting tube 1; when the air extraction of the supporting tube 1 is completed, the first through hole 503 is blocked by sliding one end of the positioning column 506 into the second through hole 504, so that the syringe 4 is disconnected from the supporting tube 1, thereby ensuring the use effect of the supporting tube 1.

[0032] Embodiment 2:

[0033] Based on Example 1, Figure 8-Figure 10 As shown, the lifting assembly 7 includes a pair of mounting seats 701 connected to the upper surface of the support plate 6 by vertical screws; a guide rod 702 is vertically fixed on one mounting seat 701; a sliding sleeve 703 is slidably sleeved on the guide rod 702; a conventional scale line 708 in the field is vertically arranged on the outer wall of the guide rod 702; the scale line 708 facilitates real-time understanding of the depth of the porous ceramic probe 2 inserted into the cement-based material; a screw rod 704 parallel to the guide rod 702 is rotatably connected on the other mounting seat 701; a conventional handle in the field is vertically fixed on the upper end of the screw rod 704; a screw sleeve 705 is threadedly matched on the screw rod 704; and a lifting strip 706 connected to the transmission frame 8 is vertically welded to the outer wall of the screw sleeve 705 and the outer wall of the sliding sleeve 703. When in use, by rotating the screw rod 704, the screw sleeve 705 and the sliding sleeve 703 are prompted to drive the transmission frame 8 up and down through the lifting strip 706, thereby realizing the lifting and lowering of the support tube 1, effectively ensuring the use effect of the support tube 1.

[0034] Among them Figure 6 and Figure 9-10 As shown, the transmission frame 8 includes a pair of hoops which are arranged side by side from top to bottom on the outer periphery of the upper part of the support tube 1; the hoops are conventional structures in the art; the upper and lower ends of the lifting bar 706 are respectively connected to the two hoops; the hoops include a pair of symmetrically arranged half-shaped hoops 801; the two half-shaped hoops 801 are connected by a pair of bolts 802; the upper and lower ends of the lifting bar 706 are both provided with third through holes 707 corresponding to the bolts 802; the bolts 802 are inserted into the third through holes 707. When in use, by firstly setting the end of the lifting bar 706 between the two half-shaped hoops 801 of the hoops, and then passing the bolts 802 through the third through holes 707 and connecting to the two half-shaped hoops 801, the transmission frame 8 is fixed to the support tube 1, and the transmission frame 8 is connected to the lifting assembly 7, which is not only convenient for installation or disassembly, but also effectively ensures the driving effect on the support tube 1.

[0035] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A cement-based material pore negative pressure testing device, comprising a vertically arranged supporting tube (1), a porous ceramic probe (2) vertically fixed at the lower end of the supporting tube (1), a pressure sensor (3) connected to the upper outer wall of the supporting tube (1), and a syringe injector (4); characterized in that: The syringe injector (4) is vertically arranged above the supporting tube (1); the lower end of the syringe injector (4) is connected to the upper end of the supporting tube (1) via an exhaust valve (5); a support plate (6) is horizontally arranged below the supporting tube (1); the upper surface of the supporting plate (6) is provided with a receiving port (601) coaxially arranged with the supporting tube (1); the lower end of the supporting tube (1) can pass through the receiving port (601) and extend to the bottom of the supporting plate (6); a lifting assembly (7) is vertically installed on the upper surface of the supporting plate (6); the lifting assembly (7) and the supporting tube (1) are connected via a transmission frame (8).

2. A cement-based material pore negative pressure testing device according to claim 1, characterized in that: The upper outer wall of the supporting tube (1) is radially connected to a bypass tube (101); the detection end of the pressure sensor (3) is fixedly inserted into the bypass tube (101).

3. A cement-based material pore negative pressure testing device according to claim 1 or 2, characterized in that: The exhaust valve (5) comprises a connecting tube (501) vertically fixed at the upper end of the supporting tube (1); the lower end of the syringe (4) is fixedly inserted into the upper end of the connecting tube (501); a sealing column (502) is vertically fixed in the connecting tube (501); a first through hole (503) is vertically opened on the sealing column (502); a second through hole (504) connected to the first through hole (503) is horizontally opened on the circumferential side wall of the sealing column (502); an extension tube (505) corresponding to the second through hole (504) is radially connected to the outer wall of the connecting tube (501); the inner thread of the extension tube (505) is matched with a positioning column (506) for blocking the first through hole (503); one end of the positioning column (506) can be slidably inserted into the second through hole (504).

4. A cement-based material pore negative pressure testing device according to claim 1, characterized in that: The lifting assembly (7) comprises a pair of mounting seats (701) both vertically fixed to the upper surface of the support plate (6); a guide rod (702) is vertically fixed on one of the mounting seats (701); a sliding sleeve (703) is slidably sleeved on the guide rod (702); a screw rod (704) parallel to the guide rod (702) is rotatably connected to the other mounting seat (701); a screw sleeve (705) is threadedly matched on the screw rod (704); and a lifting strip (706) connected to the transmission frame (8) is vertically fixed to the outer wall of the screw sleeve (705) and the outer wall of the sliding sleeve (703).

5. A cement-based material pore negative pressure testing device according to claim 4, characterized in that: The outer wall of the guide rod (702) is vertically provided with scale lines (708).

6. A cement-based material pore negative pressure testing device according to claim 4 or 5, characterized in that: The transmission frame (8) comprises a pair of hoops which are arranged side by side from top to bottom on the outer periphery of the upper part of the supporting tube (1); the upper and lower ends of the lifting strip (706) are respectively connected to the two hoops; the hoops comprise a pair of symmetrically arranged half-shaped hoops (801); the two half-shaped hoops (801) are connected via a pair of bolts (802).

7. A cement-based material pore negative pressure testing device according to claim 6, characterized in that: The upper and lower ends of the lifting strip (706) are both provided with third through holes (707) corresponding to the bolt members (802); the bolt members (802) are inserted into the third through holes (707).

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