Device and method for measuring temperature and humidity inside mass concrete by vacuum extraction

Abstract

The application discloses a device and a method for measuring the internal temperature and humidity of mass concrete by vacuumizing, which comprises a pre-embedded pipe pre-embedded in a concrete test block, a blockage prevention protective cover net for forming a temperature and humidity measuring space is arranged on the inner side of the pre-embedded pipe, a positioning protective box is arranged on the outer side of the pre-embedded pipe, and the pre-embedded pipe is used for vacuumizing and penetrating a temperature and humidity sensor during measurement; the internal temperature and humidity data of the mass concrete can be accurately obtained in real time, the preparation and implementation of a temperature and humidity control scheme are guided, and the generation of cracking is reduced; the application is different from the traditional pre-embedded sensor mode, the internal temperature of the concrete is measured by reserving a measuring space through the pre-embedded pipe, excessive repeated debugging is not needed, the circuit is clear and simple in order, time and manpower can be greatly saved, and the pouring process is rapid; and the real-time sensing of the internal temperature and humidity of the mass concrete test block is more accurate in combination with the vacuumizing mode.

Description

A device and method for measuring the internal temperature and humidity of large-volume concrete using vacuum extraction. Technical Field

[0001] This invention relates to the field of concrete construction technology for dams in water conservancy and hydropower projects, specifically to a device and method for measuring the internal temperature and humidity of large-volume concrete using vacuum extraction. Background Technology

[0002] Concrete is the most commonly used material in water conservancy and hydropower engineering construction. Although concrete has excellent mechanical properties, it is often prone to cracking due to factors such as material type, pouring process, and external environment, as it is subjected to internal and external stresses over time.

[0003] Previous studies have shown that dam cracking is mostly caused by volume expansion and contraction due to changes in temperature and humidity within the structure. In order to extend the service life of dams, it is necessary to study the cracking mechanism of large-volume concrete. Therefore, accurate and real-time acquisition of temperature and humidity data inside large-volume concrete has become one of the necessary conditions.

[0004] Currently, the measurement of internal temperature in large-volume concrete is relatively mature, with many existing measuring devices and methods, and the accuracy is also very high. However, for measuring the internal humidity of large-volume concrete, although many people have conducted research in this area and achieved different results, there is still no universally accepted and effective technology.

[0005] In the industry, technicians mostly use two methods to measure the internal moisture of large-volume concrete: pre-embedded and drilling-insertion measurement. However, both methods have room for improvement. The main reasons and difficulties are as follows:

[0006] (1) Existing humidity sensors measure the relative humidity of the air, so their working environment must have a special cavity structure that is both breathable and waterproof. However, during the pouring and compaction of large-volume concrete, a large amount of slurry and water will be generated. If these enter the cavity and come into direct contact with the sensor, they will cause short circuits in the components and damage the sensor.

[0007] (2) After the large volume of concrete is poured, the water molecules that successfully enter these measuring cavities are difficult to diffuse in a short time. Previous test data show that the relative humidity in these cavities will remain at a high level of over 95% for a considerable period of time, which cannot reflect the true humidity of the concrete.

[0008] (3) Existing humidity sensors are all quite sensitive. They are prone to drift when working in high humidity environments for a long time, and may also cause corrosion and damage to electronic components.

[0009] (4) Drilling and pre-embedding can effectively avoid damage to the sensor by the concrete slurry during the pouring and vibration of large-volume concrete, and drift caused by working in a high-humidity environment for a long time. However, drilling in the later stage can easily damage the microstructure of the concrete. In addition, the sensor does not measure the humidity of a single point after it is inserted, but the overall humidity of the columnar cavity. Furthermore, the materials used for sealing are different from the structural properties of the concrete itself, and the different curing times will interfere with the measurement results.

[0010] In summary, in order to accurately and timely obtain temperature and humidity data of large-volume concrete and take targeted temperature and humidity control measures to prevent cracking of large-volume concrete, it is necessary to develop a device and method that combines vacuum measurement of the internal temperature and humidity of large-volume concrete. Summary of the Invention

[0011] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a device and method for measuring the internal temperature and humidity of large-volume concrete by combining vacuum measurement. This method can obtain the internal temperature and humidity data of large-volume concrete in real time and accurately, guide the formulation and implementation of temperature and humidity control schemes, and reduce the occurrence of cracking.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a device for measuring the internal temperature and humidity of large-volume concrete by combining vacuuming, which includes a pre-embedded tube embedded in the concrete test block, an anti-blocking protective cover net for forming a temperature and humidity measurement space on the inner side of the pre-embedded tube, and a positioning protective box on the outer side of the pre-embedded tube. The pre-embedded tube is used for vacuuming and inserting temperature and humidity sensors during measurement.

[0013] Preferably, the embedded pipe is fixed to the concrete test block by a support frame.

[0014] Preferably, the support frame is a cubic frame structure, and the pre-embedded pipe is installed horizontally on the top of the support frame.

[0015] Preferably, the positioning and protective box is a cubic box structure, with a through hole on one side that matches the outside of the pre-embedded pipe, and the other side is open and contacts the inside of the template of the concrete test block during pouring, while the other sides of the positioning and protective box are closed.

[0016] Preferably, the position where the positioning protective box contacts the template is provided with sealant.

[0017] Preferably, the anti-blocking protective cover includes an internal support frame and an external cover.

[0018] Preferably, the embedded pipe is a polyethylene composite pipe.

[0019] Preferably, the height of the inner side of the pre-embedded pipe is lower than the height of the outer side of the pre-embedded pipe.

[0020] This invention also discloses a method for arranging the above-mentioned device for measuring the internal temperature and humidity of large-volume concrete using vacuum extraction, which includes the following steps:

[0021] Step 1): According to the design and specification requirements, erect formwork on all four sides to form a concrete pouring chamber, and then set up a support frame inside the concrete pouring chamber;

[0022] Step 2): Install the pre-embedded pipe on the top of the support frame, install the anti-blocking protective cover net inside the pre-embedded pipe, install the positioning protection box outside the pre-embedded pipe, and make the open side of the positioning protection box contact the inside of one of the templates, and apply sealant to the contact position to form a seal.

[0023] Step 3): Pour concrete into the concrete pouring chamber to form a concrete test block. Then remove the formwork. The positioning and protection box exposed on one side of the concrete test block will be the positioning point for subsequent temperature and humidity measurements.

[0024] This invention also discloses a method for measuring temperature and humidity using the aforementioned device combined with vacuum measurement of the internal temperature and humidity of large-volume concrete, which includes the following steps:

[0025] S1. Locate the position of the positioning protection box, insert the temperature and humidity sensor into the pre-embedded pipe until the temperature and humidity sensor reaches the anti-blocking protection cover; and extend one end of the vacuum pipe into the pre-embedded pipe and connect the other end to the vacuum pump.

[0026] S2. Turn on the vacuum pump and use the vacuum pipe and the pre-embedded pipe to form a negative pressure pipe to evacuate the temperature and humidity measurement space. Observe the negative pressure gauge on the vacuum pipe. After the internal vacuum is completed, close the valve on the vacuum pipe and remove the vacuum pump.

[0027] S3. The vacuum negative pressure environment causes the temperature and humidity field inside the concrete test block near the measurement space to gradually diffuse into the measurement space; when the pressure inside and outside the vacuum pipe is the same, connect the data line of the temperature and humidity sensor to the data storage device, and connect the data storage device to the data processing and analysis system.

[0028] S4. The temperature and humidity sensor detects the temperature and humidity data inside the concrete test block in real time and transmits the data to the data storage device. The data processing and analysis system reads the data in the data storage device, analyzes the real-time changes in temperature and humidity, and draws a real-time temperature and humidity curve.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention differs from traditional pre-embedded sensor methods by measuring the internal temperature of concrete through pre-embedded pipes and reserved measurement space. It eliminates the need for excessive repeated adjustments, has a clear and simple circuit, and can greatly save time and manpower, making the pouring process rapid.

[0031] 2. Considering the damage to sensors caused by traditional measurement methods, the device of this invention only requires the temperature and humidity sensor to be directly connected to the data storage device via a data cable. The temperature and humidity sensor passes directly through the pre-buried pipe and is placed inside the anti-blocking protective cover. The entire measurement process is convenient, quick, and efficient, and there is no risk of damage to the temperature and humidity sensor during the process.

[0032] 3. In traditional measurement methods, if the sensor is damaged, the temperature measurement point is directly discarded and cannot be replaced. The device of this invention can sense the internal temperature and humidity of a large-volume concrete test block in real time when measuring the internal temperature and humidity of the test block, which is more accurate. After the measurement is completed, it can be taken out directly. In addition, the internal temperature can be measured at any time as needed to sense internal changes in real time.

[0033] 4. The anti-clogging protective cover in this invention can effectively ensure that an effective gap area is formed inside, so that the temperature and humidity sensor can enter and perform the measurement process; at the same time, since the anti-clogging protective cover does not prevent water vapor from entering, it will not affect the temperature and humidity measurement process.

[0034] 5. Since the device of this invention measures temperature and humidity after the solidification of large-volume concrete, temperature and humidity sensors can be purchased as needed, and different models and styles of sensors can be used. There is no need to purchase in advance or consider the problems of damage and water ingress, which is highly economical.

[0035] 6. The positioning and protective box in this invention can serve multiple purposes. Since it contacts the inside of the template of the concrete test block during pouring, it can prevent concrete slurry from entering the embedded pipe from the outside. In addition, when the template is removed, the location of the embedded pipe can be quickly located directly through the position of the positioning and protective box, which facilitates the subsequent installation of temperature and humidity sensors and the measurement process.

[0036] 7. When measuring the internal temperature and humidity of the test block, the device of this invention evacuates the internal air. That is, a negative pressure pipeline is formed by the vacuum pipe and the pre-embedded pipe, thereby performing a vacuum process on the temperature and humidity measurement space. This allows the internal temperature and humidity field of the concrete test block near the measurement space (i.e., the location of the measurement point) to gradually diffuse into the measurement space, thus making the real-time sensing of the internal temperature and humidity of the large-volume concrete test block more accurate. Moreover, it can be directly removed after the measurement is completed. In addition, the internal temperature can be measured at any time as needed to sense internal changes in real time. Attached Figure Description

[0037] Figure 1 is a schematic diagram of the structure of a device for measuring the internal temperature and humidity of a large volume of concrete during pouring, showing the arrangement of a support frame.

[0038] Figure 2 is a schematic diagram of the structure of a device that combines vacuum measurement of the internal temperature and humidity of large-volume concrete, with pre-embedded pipes, anti-blocking protective netting and positioning protective box arranged during pouring.

[0039] Figure 3 is a schematic diagram of the structure after the template in Figure 2 has been removed;

[0040] Figure 4 is a schematic diagram of a device that combines vacuum measurement of the internal temperature and humidity of a large volume of concrete when measuring a concrete test block.

[0041] Figure 5 is an enlarged schematic diagram of the structure in Figure 4, in which a vacuum pipe and a temperature and humidity sensor are installed inside the pre-embedded pipe, the anti-blocking protective cover, and the positioning protective box.

[0042] Figure 6 is an enlarged structural diagram of the area where the anti-blocking protective cover mesh is located in Figure 5;

[0043] Figure 7 is a schematic diagram of the exploded structure of the support frame and the mesh of the anti-blocking protective cover in Figure 6. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0045] As shown in Figures 1 to 7, a device for measuring the internal temperature and humidity of a large volume of concrete by combining vacuuming includes a pre-embedded pipe 2 embedded in a concrete test block 1. The inner side of the pre-embedded pipe 2 is provided with an anti-blocking protective cover 3 for forming a temperature and humidity measurement space, and the outer side of the pre-embedded pipe 2 is provided with a positioning protective box 4. The pre-embedded pipe 2 is used for vacuuming and inserting temperature and humidity sensors 5 during measurement.

[0046] Preferably, the pre-embedded pipe 2 is fixed inside the concrete test block 1 by a support frame 6.

[0047] Preferably, the support frame 6 is a cubic frame structure, and the pre-embedded pipe 2 is installed horizontally on the top of the support frame 6. In this embodiment, the support frame 6 is a cubic metal support structure, the height of which is the height of the temperature and humidity measurement point, and multiple pre-embedded pipes 2 can be installed on its top, thus providing multiple measurement points.

[0048] Preferably, the positioning and protective box 4 is a cubic box structure, with a through hole on one side to cooperate with the outside of the embedded pipe 2, and the other side is open and contacts the inside of the template 1.1 of the concrete test block 1 during pouring. The other sides of the positioning and protective box 4 are closed. In this embodiment, the positioning and protective box 4 can play multiple roles. Since it contacts the inside of the template 1.1 of the concrete test block 1 during pouring, it can prevent concrete slurry from entering the embedded pipe 2 from the outside. In addition, when the template 1.1 is removed, the location of the embedded pipe 2 can be quickly located directly through the position of the positioning and protective box 4, which facilitates the subsequent installation of the temperature and humidity sensor 5 and the measurement process.

[0049] Preferably, sealant is provided at the contact point between the positioning protection box 4 and the template 1.1. Applying sealant improves the sealing between the positioning protection box 4 and the template 1.1, further preventing concrete slurry from entering the embedded pipe 2 from the outside. In this embodiment, the sealant is a high-performance silicone structural sealing material.

[0050] Preferably, the anti-clogging protective cover 3 includes an inner supporting frame 3.1 and an outer cover 3.2. As shown in Figures 6 and 7, in this embodiment, the supporting frame 3.1 acts as an inner support frame. In this embodiment, the supporting frame 3.1 is a cube or sphere (assuming a cube structure, its side length is 50-80mm). Its outer surface is covered with a sieve-like cover 3.2. This effectively prevents the entire anti-clogging protective cover 3 from deforming during concrete pouring or solidification, effectively ensuring the formation of an effective void area inside, allowing the temperature and humidity sensor 5 to enter and perform measurements. At the same time, since the anti-clogging protective cover 3 does not prevent water vapor from entering, it will not affect the temperature and humidity measurement process.

[0051] Preferably, the pre-embedded pipe 2 is a polyethylene composite pipe.

[0052] Preferably, the height of the inner side of the pre-embedded pipe 2 is lower than the height of the outer side of the pre-embedded pipe 2. With this design, during the pouring process, concrete slurry will not enter the pre-embedded pipe 2 from the inner side, and liquid will not easily accumulate inside the pre-embedded pipe 2.

[0053] This invention also discloses a method for arranging the above-mentioned device for measuring the internal temperature and humidity of large-volume concrete using vacuum extraction, which includes the following steps:

[0054] Step 1): As shown in Figure 1, according to the design and specification requirements, four-sided erected templates 1.1 form a concrete pouring chamber, and a support frame 6 is erected inside the concrete pouring chamber; in this embodiment, template 1.1 is a metal template, and steel pipe supports are set on its exterior to keep template 1.1 in an upright state.

[0055] Step 2): As shown in Figure 2, a pre-embedded pipe 2 is installed on the top of the support frame 6. An anti-blocking protective cover net 3 is installed inside the pre-embedded pipe 2, and a positioning protective box 4 is installed outside the pre-embedded pipe 2. The open side of the positioning protective box 4 is made to contact the inside of one of the templates 1.1, and sealant is applied to the contact position to form a seal.

[0056] Step 3): Concrete is poured into the concrete pouring chamber to form concrete test block 1. Then, the formwork 1.1 is removed. The positioning and protective box 4 exposed on one side of concrete test block 1 will serve as the positioning point for subsequent temperature and humidity measurements (as shown in Figure 3). In this embodiment, the dimensions of concrete test block 1 are: 3m high, 6m long, and 5m wide. During the pouring process, concrete is pumped and poured layer by layer. After the concrete initially sets, the internal moisture gradually evaporates due to the heat of hydration reaction of the concrete itself, and the internal temperature gradually rises due to the reaction.

[0057] This invention also discloses a method for measuring temperature and humidity using a device that combines vacuum measurement of the internal temperature and humidity of large-volume concrete, which includes the following steps:

[0058] S1. As shown in Figures 4 and 5, locate the position of the protective box 4, and insert the temperature and humidity sensor 5 into the pre-embedded pipe 2 until the temperature and humidity sensor 5 reaches the anti-blocking protective cover 3; and extend one end of the vacuum pipe 9 into the pre-embedded pipe 2, and connect the other end to the vacuum pump 10; in this embodiment, when inserting the temperature and humidity sensor 5, a rubber pad can be installed at the front end of a plastic push rod, and then the temperature and humidity sensor 5 is pushed from the outside of the pre-embedded pipe 2 into the inside of the pre-embedded pipe 2, and then reaches the anti-blocking protective cover 3. In addition, after extending part of the vacuum pipe 9 into the pre-embedded pipe 2, in order to ensure a good vacuuming effect (able to extract all the internal air), sealing material can be applied or inserted into the outer end of the pre-embedded pipe 2 to ensure good airtightness.

[0059] S2. Turn on the vacuum pump 10 and use the vacuum pipe 9 and the pre-embedded pipe 2 to form a negative pressure pipe to evacuate the temperature and humidity measurement space. Observe the negative pressure gauge 9.1 on the vacuum pipe 9. After the internal vacuum is completed, close the valve 9.2 on the vacuum pipe 9 and remove the vacuum pump 10.

[0060] S3. The vacuum negative pressure environment causes the temperature and humidity field inside the concrete test block 1 near the measurement space to gradually diffuse into the measurement space; when the pressure inside and outside the vacuum pipe 9 is the same, connect the data line 5.1 of the temperature and humidity sensor 5 to the data storage device 7, and connect the data storage device 7 to the data processing and analysis system 8.

[0061] S4. Temperature and humidity sensor 5 detects the temperature and humidity data inside the concrete test block 1 in real time and transmits the data to data storage device 7. Data processing and analysis system 8 reads the data from data storage device 7, analyzes the real-time changes in temperature and humidity, and plots a real-time temperature and humidity curve. In this embodiment, data storage device 7 can be a paperless recorder, and data processing and analysis system 8 can be a laptop computer.

[0062] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for measuring temperature and humidity using a device that combines vacuum measurement of the internal temperature and humidity of a large volume of concrete, the device comprising an embedded tube (2) pre-embedded in a concrete test block (1), the inner side of the embedded tube (2) being provided with an anti-blocking protective cover (3) for forming a temperature and humidity measurement space, and the outer side of the embedded tube (2) being provided with a positioning protective box (4), the embedded tube (2) being used for vacuuming and inserting temperature and humidity sensors (5) during measurement; it includes the following steps: S1. Locate the position of the positioning protection box (4), insert the temperature and humidity sensor (5) into the pre-embedded pipe (2) until the temperature and humidity sensor (5) reaches the anti-blocking protective cover (3); and insert one end of the vacuum pipe (9) into the pre-embedded pipe (2), and connect the other end to the vacuum pump (10); S2. Turn on the vacuum pump (10), and perform a vacuuming process on the temperature and humidity measurement space through the negative pressure pipe formed by the vacuum pipe (9) and the pre-embedded pipe (2), observe the negative pressure gauge (9.1) on the vacuum pipe (9), and after the internal vacuuming is completed, close the valve (9.2) on the vacuum pipe (9) and remove the vacuum pump (10); S3. The negative pressure environment causes the temperature and humidity field inside the concrete test block (1) near the measurement space to gradually diffuse into the measurement space; when the pressure inside and outside the vacuum pipe (9) is consistent, the data line (5.1) of the temperature and humidity sensor (5) is connected to the data storage device (7), and the data storage device (7) is connected to the data processing and analysis system (8); S4, the temperature and humidity sensor (5) detects the temperature and humidity data inside the concrete test block (1) in real time and transmits the data to the data storage device (7), the data processing and analysis system (8) reads the data in the data storage device (7), analyzes the real-time changes in temperature and humidity data, and draws a real-time temperature and humidity curve.

2. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 1, characterized in that: The pre-embedded pipe (2) is fixed inside the concrete test block (1) by the support frame (6).

3. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 2, characterized in that: The support frame (6) is a cubic frame structure, and the pre-embedded pipe (2) is installed horizontally on the top of the support frame (6).

4. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 1, characterized in that: The positioning protection box (4) is a cubic box structure. One side of it has a perforation that matches the outside of the pre-embedded pipe (2), and the other side is open and contacts the inside of the template (1.1) of the concrete test block (1) during pouring. The other sides of the positioning protection box (4) are closed.

5. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 4, characterized in that: The positioning protection box (4) is provided with sealant at the position where it contacts the template (1.1).

6. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 1, characterized in that: The anti-blocking protective cover (3) includes an internal support frame (3.1) and an external cover (3.2).

7. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 1, characterized in that: The pre-embedded pipe (2) is a polyethylene composite pipe.

8. The method for measuring temperature and humidity using a device combining vacuum measurement of the internal temperature and humidity of large-volume concrete as described in claim 1, characterized in that: The height of the inner side of the pre-embedded pipe (2) is lower than the height of the outer side of the pre-embedded pipe (2).

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