CN209841595U - Concrete capillary water absorption rate real-time monitoring device under load - Google Patents

Concrete capillary water absorption rate real-time monitoring device under load Download PDF

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CN209841595U
CN209841595U CN201920406604.4U CN201920406604U CN209841595U CN 209841595 U CN209841595 U CN 209841595U CN 201920406604 U CN201920406604 U CN 201920406604U CN 209841595 U CN209841595 U CN 209841595U
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water
steel plate
concrete
right steel
computer
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鲍玖文
李树国
张鹏
赵铁军
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Qingdao University of Technology
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Qingdao University of Technology
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Abstract

The utility model belongs to the technical field of concrete material durability monitoring equipment, in particular to a real-time monitoring device for capillary water absorption rate of concrete under load, the main structure comprises a concrete sample, a left steel plate, a right steel plate, a preformed hole, a threaded rod, a spring, a pull nut, a press nut, a water suction box, a sealing ring, a cover plate, a first high-strength bolt, a second high-strength bolt, a water injection pipe, a water injection valve, a water supply box, a water outlet pipe, a silica gel hose, a water storage tank, an air pressure balance hole, a quality sensor, a multi-channel data collector, a computer and a strain gauge, force transmission is carried out between the right steel plate and the pull nut and the press nut through the spring, the quality sensor is connected with the computer, the change rule of the mass reduction amount of the water storage tank and the time can be transmitted to the computer in real time and draw the accumulated water suction amount curve of the, the high-precision measurement requirement of the capillary water absorption of the concrete test piece can be met under different loads.

Description

Concrete capillary water absorption rate real-time monitoring device under load
The technical field is as follows:
the utility model belongs to the technical field of concrete material durability monitoring facilities, concretely relates to concrete capillary water absorption rate real-time supervision device under holding.
Background art:
the concrete is a heterogeneous material with multiple phases and multiple scales, in the service process, external aggressive ions enter the interior of the concrete in various forms such as diffusion, permeation and migration, medium invasion can be accelerated by a continuous path formed by internal pores and microcracks, and the generation and development of internal pore structures and cracks of the concrete can be caused by the action of external load, so that the degradation mechanism of the concrete under the coupling action of the load and the environment is more complex, for example: in the concrete in a freeze-thaw environment, the internal expansion stress of the concrete caused by the alternate change of pore water in liquid and solid phases can increase new microcracks, thereby increasing the invasion of harmful ions. In addition to this, water absorption is widely used to evaluate the water absorption characteristics of building materials, and thus, it is used as an important index for describing durability of building materials. The device and the method for researching the capillary water absorption rule of the concrete under the action of continuous load and monitoring the concrete in real time are important prerequisites for evaluating the durability of the marine concrete structure and predicting the service life.
In the prior art, a plurality of devices for measuring the water absorption of concrete are provided: the Chinese patent 201420535726.0 discloses a tester for testing the water absorption of concrete surface, which is a water container made of impervious material, the circumference of the opening of the container is provided with a rim; the container is filled with water absorbing material and quantitative water, the edge of the water container is coated with a hot melt adhesive layer, the surface of the hot melt adhesive layer is pressed with a sealing plastic film, and the thickness of the container is 0.5-1.5 mm; the height of the container is between 8 and 15mm, the inner diameter circle of the edge of the circumference of the opening part of the container is an opening and forms a whole with the bottom of the container, the thickness of the material of the container is 0.5 to 1mm, the outer diameter is 10mm larger than the inner diameter, and the inner diameter of the edge of the circumference of the opening part of the container is within the range; the outer diameter is 10mm larger than the inner diameter; the automatic test system for the capillary water absorption of the concrete surface disclosed in the Chinese patent 201310441396.9 comprises a constant-pressure water supply unit, an electronic balance and a test piece water absorption unit, wherein the constant-pressure water supply unit is communicated with the test piece water absorption unit through a water outlet pipe, a silica gel hose and a water inlet pipe; the constant-pressure water supply unit consists of a constant-pressure water supply sealing bottle, a gas communicating pipe, a balance air inlet pipe and a water outlet pipe; the electronic balance is arranged at the bottom end of the constant-pressure water supply sealing bottle and is used for measuring the weight of the constant-pressure water supply unit; the gas communicating pipe and the balance air inlet pipe are both arranged at the upper end of the constant-pressure water supply sealed bottle, one end of the gas communicating pipe inside the constant-pressure water supply sealed bottle is arranged at the upper end close to the constant-pressure water supply sealed bottle, and one end of the balance air inlet pipe inside the constant-pressure water supply sealed bottle is arranged at the lower end close to the constant-pressure water supply sealed bottle; the upper part of the gas communicating pipe is provided with a gas valve; the upper part of the balance air inlet pipe is provided with an air valve; the bottom of the balance air inlet pipe is provided with a needle tube; one end of a water outlet pipe with a valve is communicated with the side end of the bottom of the constant-pressure water supply sealing bottle, the other end of the water outlet pipe is communicated with a water inlet pipe through a silica gel hose, and the water inlet pipe is communicated with the side surface of the bottom of the sample sealing chamber; the test piece water absorption unit consists of a test piece sealing chamber, a water inlet pipe, a drain valve, a regulating valve, an L-shaped water level meter and a test piece supporting piece; the upper part of the sample sealing chamber is provided with a level gauge, the lower end of the sample sealing chamber is provided with a water inlet pipe, the lower end of the right side of the sealing chamber is provided with an L-shaped water level meter, and the other end of the L-shaped water level meter is arranged upwards; the upper end of the right side of the sample sealing chamber is provided with an adjusting valve; the drain valve is arranged at the bottom of the sample sealing chamber; three equal-height sample supporting pieces are arranged on the inner side of the bottom of the sample sealing chamber; the test piece water absorption unit also comprises a height adjusting pin and a level meter; three equal-height adjusting feet are arranged outside the sample sealing chamber and are positioned on a horizontal operating platform; the measuring range of the electronic balance is 1000g, and the precision is 0.001 g; the gas communicating pipe, the balance air inlet pipe, the water outlet pipe, the water inlet pipe and the L-shaped water level meter are made of organic glass; the distance of the top end of the L-shaped water level meter higher than the top end of the sample support piece in the vertical direction is 5 mm; the cement-based material crack water absorption process visualization and water absorption rate measurement device disclosed in Chinese patent 201810254473.2 comprises an empty box and a camera, wherein a fluorescent lamp and a tray for storing a fluorescein solution are placed in the empty box; a plurality of supporting pieces are arranged in the tray, the heights of the top surfaces of the supporting pieces are equal to form a horizontal supporting plane, and the bottom surface of the cement-based material test block is horizontally placed on the supporting plane; the height of the supporting plane is lower than the highest water storage height of the tray; the shooting area of the camera covers the cement-based material test block placing area above the supporting plane; the illumination range of the fluorescent lamp covers the imaging area of the cement-based material test block in the camera.
The concrete structure in service usually bears the coupling effect of load and environmental factor, and the concrete water absorption index has great difference with the actual condition under the single factor of laboratory. At present, in the research on the concrete moisture transmission mechanism under the load action, because the water absorption test is mostly carried out mainly aiming at the unloading damage test piece under the restriction of laboratory conditions, a certain degree of closure phenomenon appears in concrete after unloading, and the damage condition and the medium transmission property under the actual condition cannot be truly reflected. Meanwhile, most of the existing testing means adopt a method of manually weighing the mass of a concrete sample at regular time to obtain the water absorption capacity of the concrete, so that not only is real-time and continuous monitoring of the water absorption process of the concrete not realized, but also artificial errors are easily caused, and the change rule of water-carrying moisture transmission cannot be accurately revealed by test data. Therefore, in view of the above problems, it is necessary to develop a testing device for monitoring the capillary water absorption change of concrete under load in real time, which is helpful for accurately evaluating the durability of concrete and predicting the service life of concrete.
The invention content is as follows:
the utility model aims to overcome what prior art exists is difficult to realize that the concrete is applyed and is lasted load and the hydrophilic coupling process of capillary, can't carry out real-time, continuous monitoring's problem to the test piece water absorption capacity, research and development one kind hold concrete capillary water absorption rate real-time supervision device down.
In order to achieve the purpose, the main structure of the real-time monitoring device for the capillary water absorption rate of the concrete under load comprises a concrete test piece, a left steel plate, a right steel plate, a preformed hole, a threaded rod, a spring, a pull nut, a press nut, a suction box, a sealing ring, a cover plate, a first high-strength bolt, a second high-strength bolt, a water injection pipe, a water injection valve, a water supply tank, a water outlet pipe, a silica gel hose, a water storage tank, a pressure balance hole, a quality sensor, a multi-channel data acquisition device, a computer and a strain gauge; the left vertical surface of a concrete sample with a cuboid structure is connected with a left steel plate with a rectangular plate structure in an adhesive manner, the right vertical surface of the concrete sample is connected with a right steel plate with a rectangular plate structure in an adhesive manner, two ends of the left steel plate and the right steel plate are respectively provided with a preformed hole with an oval structure, two cylindrical threaded rods pass through the right steel plate and then are connected with the left steel plate, the threaded rod on the left side of the right steel plate is sleeved with a spring and a pull nut, the threaded rod on the right side of the right steel plate is sleeved with the spring and then is connected with a pressing nut, a water suction box with an inner hollow structure is arranged below the concrete sample, the left steel plate and the right steel plate, the periphery where the concrete sample and the water suction box are intersected is provided with a sealing ring with an annular structure, two side edges of the sealing ring which are parallel to the threaded rod are respectively provided with a cover plate with a rectangular plate structure, the left facade of suction box is provided with the water injection pipe, be provided with two water injection valves on the water injection pipe, the water injection pipe is connected with the feed tank of cavity formula structure, the top surface of suction box is provided with the outlet pipe, the outlet pipe is connected with the silica gel hose, the silica gel hose is connected with the storage water tank of cavity formula structure, the top of storage water tank is provided with atmospheric pressure balancing hole, the below of storage water tank is provided with mass sensor, mass sensor is connected with multichannel data collection station, multichannel data collection station is connected with the computer and pastes the foil gage electricity in concrete sample side respectively, mass sensor passes through USB with the computer and is connected.
Compared with the prior art, the utility model, have following advantage: 1. force is transferred between the right steel plate and the pull nut and between the right steel plate and the press nut through a spring, so that stress loss caused by creep of a concrete test piece is reduced, a strain gauge adhered to the concrete test piece can monitor the stress level of the concrete test piece in real time, and the stress can be ensured to be in a target state by adjusting the pull nut or the press nut in time after the stress loss occurs; 2. because the mass sensor is connected with the computer, the change rule of the mass reduction amount and the time of the water storage tank can be transmitted to the computer in real time, and the cumulative water absorption curve of the concrete test piece can be drawn in real time, so that the error caused by artificial reading is reduced; 3. the cover plate is connected with the water suction box through a bolt, the left steel plate and the right steel plate are connected with the water suction box through high-strength bolts, the water outlet pipe is connected with the water storage tank through a silica gel hose, the operation is simple, the water storage tank can be repeatedly utilized, the water storage tank is placed on the quality sensor to continuously test the capillary water absorption capacity of the concrete sample in real time, and the high-precision measurement requirement of the capillary water absorption of the concrete sample can be met under different loads; the device has the advantages of simple structure, simplicity and convenience in operation and friendly use environment, realizes the continuous load application, measures the surface water absorption of the concrete sample, solves the coupling problem of the load application and the concrete water absorption process, reduces the influence of the closure of the crack after unloading on the capillary water absorption of the concrete, and provides powerful support for accurately evaluating the influence mechanism and the change rule of the load application on the capillary water absorption of the concrete.
Description of the drawings:
fig. 1 is a schematic diagram of the main structure principle of the present invention.
Fig. 2 is the utility model relates to a concrete sample and left steel sheet and right steel sheet's relation of connection sketch map.
Fig. 3 is the utility model relates to a concrete sample, left steel sheet and right steel sheet and suction box's relation of connection sketch map.
The specific implementation mode is as follows:
the present invention will be described in further detail below by way of examples with reference to the accompanying drawings.
Example 1:
the main structure of the under-load concrete capillary water absorption real-time monitoring device comprises a concrete test piece 1, a left steel plate 2, a right steel plate 3, a preformed hole 4, a threaded rod 5, a spring 6, a pull nut 7, a press nut 8, a water suction box 9, a sealing ring 10, a cover plate 11, a first high-strength bolt 12, a second high-strength bolt 13, a water injection pipe 14, a water injection valve 15, a water supply tank 16, a water outlet pipe 17, a silica gel hose 18, a water storage tank 19, an air pressure balance hole 20, a quality sensor 21, a multi-channel data acquisition unit 22, a computer 23 and a strain gauge 24; the left vertical surface of a concrete sample 1 with a cuboid structure is connected with a left steel plate 2 with a rectangular plate structure in an adhesive manner, the right vertical surface of the concrete sample 1 is connected with a right steel plate 3 with a rectangular plate structure in an adhesive manner, two ends of the left steel plate 2 and the right steel plate 3 are respectively provided with a preformed hole 4 with an oval structure, two cylindrical threaded rods 5 pass through the right steel plate 3 and then are connected with the left steel plate 2, the threaded rod 5 on the left side of the right steel plate 3 is sleeved with a spring 6 and a pull nut 7, the threaded rod 5 on the right side of the right steel plate 3 is sleeved with the spring 6 and then is connected with a press nut 8, a water suction box 9 with an inner hollow structure is arranged below the concrete sample 1, the left steel plate 2 and the right steel plate 3, a sealing ring 10 with an annular structure is arranged on the periphery of the intersection of the concrete sample 1 and the water suction box, a cover plate 11 is connected with a water suction box 9 through a first high-strength bolt 12, a left steel plate 2 and a right steel plate 3 are respectively connected with the water suction box 9 through a reserved hole 4 through a second high-strength bolt 13, a water injection pipe 14 is arranged on the left vertical surface of the water suction box 9, two water injection valves 15 are arranged on the water injection pipe 14, the water injection pipe 14 is connected with a water supply box 16 of an internal hollow structure, a water outlet pipe 17 is arranged on the top surface of the water suction box 9, the water outlet pipe 17 is connected with a silica gel hose 18, the silica gel hose 18 is connected with a water storage tank 19 of the internal hollow structure, an air pressure balance hole 20 is arranged on the top of the water storage tank 19, a mass sensor 21 is arranged below the water storage tank 19, the mass sensor 21 is connected with a multi-channel data collector 22, the multi-channel data collector 22 is respectively and electrically connected with a computer 23 and a strain gauge 24.
The lower surface of a concrete sample 1 related to the embodiment is a water absorption surface, the water absorption surface of the concrete sample 1 is 3-5mm lower than the lower surfaces of a left steel plate 2 and a right steel plate 3, and the water absorption surface of the concrete sample 1 is 1-2mm lower than the bottom surface of a sealing ring 10; the left steel plate 2 and the right steel plate 3 are the same in thickness and are both 20-50mm, so that the stress of the loading surface of the concrete sample 1 is uniform, force is transferred between the right steel plate 3 and the pull nut 7 and the compression nut 8 through the spring 6, and the stress loss caused by creep of the concrete sample 1 can be avoided; the water suction tank 9, the water injection pipe 14, the water outlet pipe 17 and the water storage tank 19 are all made of organic glass, the diameter of the water injection pipe 14 is larger than that of the water outlet pipe 17, so that the water supply tank 16 is filled with water quickly, the influence of short-term water suction of the concrete test piece 1 on a later-stage measurement result in the water injection process is reduced, preferably, the outer diameter and the inner diameter of the water injection pipe 14 are respectively 10-15mm and 8-13mm, the outer diameter and the inner diameter of the water outlet pipe 17 are respectively 3-5mm and 2-4mm, the top surface of the water outlet pipe 17 is 2-3mm higher than the top surface of the sealing ring 10, the water storage tank 19 is of a square structure, the wall thickness of the tank body of the water storage tank 19 is 0.5-2mm, the mass is smaller than 200g, the gradient of the inner bottom surface of the water storage tank 19 is 2 degrees; the thickness of the sealing ring 10 is 1-2 mm; the first high-strength bolt 12 and the second high-strength bolt 13 are pressure-bearing high-strength bolts and have an extrusion effect on the sealing ring 10; the measuring range of the mass sensor 21 is 0-500g, and the precision is 0.01 g; the multi-channel data acquisition unit 22 is a data acquisition product with a USB interface, and can be connected with various desktop computers, notebook computers and industrial personal computers with USB interfaces to form a high-performance data acquisition and measurement system; the computer 23 is internally stored with a program capable of compiling and recording the relationship between the mass reduction amount of the water storage tank 19 and the time; the strain gage 24 is a resistive strain gage.
The technical process of the device for monitoring the capillary water absorption of the concrete under load in real time in the embodiment comprises the following steps:
firstly, a left vertical surface and a right vertical surface of a concrete sample 1 with the length, the width and the height of 100mm, 100mm and 50mm are respectively hermetically connected with a left steel plate 2 and a right steel plate 3 by using building structure glue, four sides of 100mm multiplied by 50mm of the concrete sample 1 are subjected to waterproof treatment by using epoxy resin, a strain gauge 24 is pasted on the upper side surface, the strain gauge 24 is connected to a computer 23 through a multi-channel data acquisition device 22 so as to monitor the stress state of the concrete sample 1 in real time, the left steel plate 2 and the right steel plate 3 are connected by using two threaded rods 5, a spring 6, a pull nut 7 and a press nut 8 are sleeved on the threaded rod 5, acting force is applied to the concrete sample 1 through a press machine, after the concrete sample 1 reaches a preset stress level displayed on the computer 23, the pull nut 7 (the press nut 8) is loosened, and the press nut 8 (the pull nut 7) is screwed;
placing a sealing ring 10 on a water suction box 9, erecting cover plates 11 on two sides of the sealing ring 10, placing a concrete test piece 1 on the sealing ring 10, connecting the cover plates 11 with the water suction box 9 by using a first high-strength bolt 12, respectively connecting a left steel plate 2 and a right steel plate 3 with the water suction box 9 by using a second high-strength bolt 13 through a preformed hole 4, hermetically connecting the concrete test piece 1 with the water suction box 9 by using the sealing ring 10, connecting a water outlet pipe 17 with a water storage tank 19 by using a silica gel hose 18, placing the water storage tank 19 on a quality sensor 21, and connecting the quality sensor 21 to a computer 23;
thirdly, opening a water injection valve 15, enabling water in the water supply tank 16 to flow into the water storage tank 19, closing the water injection valve 15 when the mass increase value of the water storage tank 19 reaches 220-280g, keeping the water level line in the water supply tank 16 to be 10-15mm higher than the bottom surface of the water storage tank 19 in the water adding process, starting a timer after stopping adding water, running a program for recording the relationship between the mass reduction amount of the water storage tank 19 and time in the computer 23, recording the initial mass of the water storage tank 19, and monitoring the mass reduction amount of the water storage tank 19 in real time by the computer 23;
fourthly, recording the change rule of the mass reduction amount of the water storage tank 19 along with time through the computer 23, wherein the numerical value of the mass reduction amount of the water storage tank 19 is equal to the numerical value of the water absorption amount of the concrete sample 1 in the vertical loading direction, and the computer 23 carries out data processing on the change rule of the mass reduction amount of the water storage tank 19 along with time, and draws the accumulated water absorption amount curve of the concrete sample 1 under load in real time.

Claims (1)

1. A concrete capillary water absorption real-time monitoring device under load is characterized in that a main body structure comprises a concrete test piece, a left steel plate, a right steel plate, a preformed hole, a threaded rod, a spring, a pull nut, a press nut, a water suction box, a sealing ring, a cover plate, a first high-strength bolt, a second high-strength bolt, a water injection pipe, a water injection valve, a water supply box, a water outlet pipe, a silica gel hose, a water storage tank, an air pressure balance hole, a quality sensor, a multi-channel data acquisition unit, a computer and a strain gauge; the left vertical surface of a concrete sample with a cuboid structure is connected with a left steel plate with a rectangular plate structure in an adhesive manner, the right vertical surface of the concrete sample is connected with a right steel plate with a rectangular plate structure in an adhesive manner, two ends of the left steel plate and the right steel plate are respectively provided with a preformed hole with an oval structure, two cylindrical threaded rods pass through the right steel plate and then are connected with the left steel plate, the threaded rod on the left side of the right steel plate is sleeved with a spring and a pull nut, the threaded rod on the right side of the right steel plate is sleeved with the spring and then is connected with a pressing nut, a water suction box with an inner hollow structure is arranged below the concrete sample, the left steel plate and the right steel plate, the periphery where the concrete sample and the water suction box are intersected is provided with a sealing ring with an annular structure, two side edges of the sealing ring which are parallel to the threaded rod are respectively provided with a cover plate with a rectangular plate structure, the left facade of suction box is provided with the water injection pipe, be provided with two water injection valves on the water injection pipe, the water injection pipe is connected with the feed tank of cavity formula structure, the top surface of suction box is provided with the outlet pipe, the outlet pipe is connected with the silica gel hose, the silica gel hose is connected with the storage water tank of cavity formula structure, the top of storage water tank is provided with atmospheric pressure balancing hole, the below of storage water tank is provided with mass sensor, mass sensor is connected with multichannel data collection station, multichannel data collection station is connected with the computer and pastes the foil gage electricity in concrete sample side respectively, mass sensor passes through USB with the computer and is connected.
CN201920406604.4U 2019-03-28 2019-03-28 Concrete capillary water absorption rate real-time monitoring device under load Active CN209841595U (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109781578A (en) * 2019-03-28 2019-05-21 青岛理工大学 One kind holding the lower concrete capillary water absorption rate real-time monitoring device of load

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109781578A (en) * 2019-03-28 2019-05-21 青岛理工大学 One kind holding the lower concrete capillary water absorption rate real-time monitoring device of load
CN109781578B (en) * 2019-03-28 2023-09-22 青岛理工大学 Real-time monitoring device for capillary water absorption of concrete under load

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