Volumetric deformation testing method and apparatus for mass concrete

Abstract

A volumetric deformation testing apparatus for mass concrete, the apparatus comprising a protective cylinder (1), wherein a connection block (11) is provided in an inner cavity of the protective cylinder (1); a positioning rod (12) is provided on the upper end of the connection block (11), and a detection assembly (2) is provided on the upper end of the positioning rod (12); and by means of the detection assembly (2), the volumetric deformation situation of concrete is monitored.

Description

A method and device for testing volume deformation of large-volume concrete Technical Field

[0001] The present invention relates to concrete detection technology, and in particular to a volume deformation testing method and device for large-volume concrete. Background Art

[0002] Cement concrete is currently the most widely used civil engineering material. Mechanical strength and volume stability are the most important performance indicators affecting the engineering application of this material. It is well known that concrete's high strength is due to the hydration reaction between cement particles and water. This hydration reaction requires the presence of liquid water and a long curing period to achieve the design strength requirements. Furthermore, even in the presence of liquid water, the hydration rate of cement is significantly reduced in low-temperature environments, resulting in slow strength growth. Therefore, when fresh concrete is exposed to low temperatures without pre-curing, with insufficient pre-curing time, or with a sudden drop in temperature, the cement paste structure is not fully formed, resulting in a large amount of free water in the concrete that can freeze. Furthermore, the cement paste's low strength is insufficient to resist the expansion force generated by the freezing of free water, leading to the formation and propagation of microcracks in the concrete, which in turn affects the concrete's strength and long-term performance. To prevent premature freezing damage to concrete, extensive research and practical applications have focused on measures such as adding antifreeze agents to lower the freezing point of water, adding early-strength agents to accelerate cement hydration and strength development, and using external insulation curing or additional heat sources to prevent or delay the freezing of free water in the concrete.

[0003] The existing concrete volume deformation test method has low accuracy, poor reliability, high test cost, overly simple test equipment, low degree of automation, and is unable to accurately monitor the actual situation of concrete volume deformation, making it impossible to accurately record the expansion or contraction state of concrete. Therefore, a method and device for testing the volume deformation of large-volume concrete were developed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for testing the volume deformation of large-volume concrete to solve the above-mentioned deficiencies in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a method for testing the volume deformation of large-volume concrete, comprising the following steps:

[0006] S1. Prepare specimens: Use rectangular specimens, cylindrical specimens or testing equipment to prepare concrete specimens of different sizes as needed;

[0007] S2. Initial measurement: Before the specimen is loaded, measure the dimensions of the specimen or testing equipment and record the initial length, width, height and position;

[0008] S3. Apply load: Mark the measuring points on the surface of the test piece or testing equipment, and then apply the predetermined load. The load can be applied by deadweight, external loading equipment or immersion in water;

[0009] S4. Regular measurement: During the force application process, the dimensional changes of the specimen are measured regularly, and the changes in the length, width, height and position of the specimen over time are recorded;

[0010] S5. Data analysis: Analyze the shrinkage and deformation of concrete specimens or testing equipment based on the test data, including free shrinkage, constrained shrinkage, temperature expansion and hydration expansion.

[0011] A device for testing the volume deformation of large-volume concrete comprises a protective cylinder, an inner cavity of the protective cylinder is provided with a connecting block, an upper end of the connecting block is provided with a positioning rod, and an upper end of the positioning rod is provided with a detection component, through which the volume deformation of the concrete is monitored;

[0012] Among them, the detection component includes a gear, a positioning block is provided in the middle position of the lower end of the gear, and a support plate is fixedly installed at the lower end of the positioning block. The longitudinal section of the support plate is pentagonal, and the inner wall of each end of the support plate is slidably installed with an adjustment member, and a vertical rod is provided at the lower end of the adjustment member, and the outer surface of the vertical rods provided at the lower ends of two adjacent adjustment members is provided with a flexible plate.

[0013] As a further optimization solution of the present invention, multiple groups of arc grooves are opened at one end of the gear, and the multiple groups of arc grooves are evenly distributed at one end of the gear, and a slider is slidably installed on the inner wall of each arc groove.

[0014] As a further optimization solution of the present invention, a transmission block is provided on the upper end of the support plate and on one side of the gear, and the outer surface of the transmission block is meshed with the outer surface of the gear.

[0015] As a further optimized solution of the present invention, the adjusting member includes a movable plate, and the upper end of the movable plate is fixedly connected to the lower end of the sliding block.

[0016] As a further optimization solution of the present invention, a clamping block is provided in the inner cavity of one end of the movable plate, and a detection block is rotatably mounted on one end of the clamping block.

[0017] As a further optimization solution of the present invention, an adjustment plate is slidably mounted on the outer surface of the detection block, and an arc plate is fixedly mounted on one end of the adjustment plate away from the detection block.

[0018] As a further optimization solution of the present invention, a groove is provided on one side of the detection block, and a detection piece is provided on the inner wall of the groove. The end of the detection piece away from the detection block is connected to the adjustment plate, and an elastic piece is provided on the outer surface of the detection piece.

[0019] Compared with the prior art, the present invention provides a method and device for testing the volume deformation of large-volume concrete. When the adjusting member moves, it drives the slider fixedly installed on its upper end to move. Since the outer surface of the slider is slidably connected to the inner wall of the arc-shaped groove, when the slider moves, it synchronously drives the gear to rotate around the positioning block. At the same time, the outer surface of the gear is engaged with a transmission block, so that the gear drives the transmission block to rotate when it rotates. The expansion or contraction of the concrete is recorded by the angle of rotation of the transmission block.

[0020] When the adjustment block moves, the detection piece set in the inner cavity of the detection block is squeezed and slid, and the movement data is transmitted to the inside of the control device in real time for recording the time point of concrete expansion or contraction. At the same time, a temperature detector can be set on one side of the control device to record the temperature in the current environment. After the detection piece records the data, the problem condition of the current environment is recorded synchronously, which is convenient for subsequent judgment of the expansion or contraction of concrete in different temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] FIG1 is a schematic diagram of an overall process provided by an embodiment of the present invention.

[0023] FIG2 is a schematic diagram of the structure of a detection component provided by an embodiment of the present invention.

[0024] FIG3 is a longitudinal cross-sectional view of the internal structure of the detection component provided by an embodiment of the present invention.

[0025] FIG4 is a cross-sectional view of the internal structure of the detection component provided by an embodiment of the present invention.

[0026] FIG5 is a schematic diagram of the structure of the adjusting member provided in an embodiment of the present invention.

[0027] FIG6 is a longitudinal cross-sectional view of the internal structure of the adjusting member provided in an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1. Protective tube; 2. Detection assembly; 11. Connecting block; 12. Positioning rod; 21. Gear; 211. Transmission block; 22. Arc groove; 23. Slider; 24. Positioning block; 25. Support plate; 26. Adjustment member; 27. Arc plate; 28. Vertical pole; 29. ​​Flexible plate; 261. Adjustment plate; 262. Movable plate; 263. Snap-in block; 264. Detection block; 265. Groove; 266. Detection member; 267. Elastic member. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, unless otherwise expressly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrally connected; they can be mechanically connected or electrically connected; they can be directly connected or indirectly connected through an intermediate medium, or they can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0032] Referring to FIG1 , a method for testing the volume deformation of large-volume concrete includes the following steps:

[0033] S1. Prepare specimens: Use rectangular specimens, cylindrical specimens or testing equipment to prepare concrete specimens of different sizes as needed;

[0034] S2. Initial measurement: Before the specimen is loaded, measure the dimensions of the specimen or testing equipment and record the initial length, width, height and position;

[0035] S3. Apply load: Mark the measuring points on the surface of the test piece or testing equipment, and then apply the predetermined load. The load can be applied by deadweight, external loading equipment or immersion in water;

[0036] S4. Regular measurement: During the force application process, the dimensional changes of the specimen are measured regularly, and the changes in the length, width, height and position of the specimen over time are recorded;

[0037] S5. Data analysis: Analyze the shrinkage and deformation of concrete specimens or testing equipment based on the test data, including free shrinkage, constrained shrinkage, temperature expansion and hydration expansion. two

[0038] Please refer to Figures 2-6, a volume deformation testing device for large-volume concrete includes a protective tube 1, the inner cavity of the protective tube 1 is provided with a connecting block 11, the upper end of the connecting block 11 is provided with a positioning rod 12, and the upper end of the positioning rod 12 is provided with a detection component 2. The detection component 2 is used to monitor the volume deformation of the concrete.

[0039] In this solution, the inner cavity of the positioning rod 12 is provided with a sensor or other device with a detection function for detecting the distribution of gas inside the concrete and transmitting the data to the control device in real time.

[0040] Other sensors or usage forms can also be selected to determine and record the location of bubbles inside the concrete.

[0041] Furthermore, the detection component 2 includes a gear 21, a positioning block 24 is provided at the middle position of the lower end of the gear 21, and a support plate 25 is fixedly installed at the lower end of the positioning block 24. The longitudinal section of the support plate 25 is pentagonal, and the inner wall of each end of the support plate 25 is slidably installed with an adjustment member 26, and a vertical rod 28 is provided at the lower end of the adjustment member 26. The outer surface of the vertical rod 28 provided at the lower end of two adjacent adjustment members 26 is provided with a flexible plate 29.

[0042] In this embodiment, a partition is provided at the upper end of the positioning block 24, and the partition is located at the upper end of the gear 21, which is used to limit the positioning block 24 and prevent the positioning block 24 from being separated from the gear 21. At the same time, the arc-shaped plate 27 provided at the end of the adjustment member 26 extends into the interior of the concrete, so that when the upper end of the concrete expands or contracts, the data of the concrete reaction can be directly recorded in the control device.

[0043] The flexible plate 29 is used to wrap the concrete so that it will not leak before solidifying. The flexible plate 29 is limited by multiple groups of vertical poles 28 so that after the flexible plate 29 wraps the concrete, it will not shake. The expansion or contraction of the concrete inside can also be recorded through the vertical poles 28.

[0044] Furthermore, one end of the gear 21 is provided with multiple groups of arc grooves 22, and the multiple groups of arc grooves 22 are evenly distributed on one end of the gear 21. At the same time, a slider 23 is slidably installed on the inner wall of each arc groove 22; a transmission block 211 is provided on the upper end of the support plate 25 and on one side of the gear 21, and the outer surface of the transmission block 211 is engaged with the outer surface of the gear 21.

[0045] Specifically, when the adjusting member 26 moves, it drives the slider 23 fixed on its upper end to move. Since the outer surface of the slider 23 is slidably connected to the inner wall of the arc-shaped groove 22, when the slider 23 moves, it synchronously drives the gear 21 to rotate around the positioning block 24. At the same time, the outer surface of the gear 21 is engaged with the transmission block 211, so that the gear 21 drives the transmission block 211 to rotate when it rotates. The expansion or contraction of the concrete is recorded by the rotation angle of the transmission block 211. A sensor is provided on the upper end of the transmission block 211 and is connected to an external control device.

[0046] The adjusting member 26 includes a movable plate 262, and the upper end of the movable plate 262 is fixedly connected to the lower end of the slider 23; a clamping block 263 is provided in the inner cavity of one end of the movable plate 262, and a detection block 264 is rotatably installed at one end of the clamping block 263; an adjusting plate 261 is slidably installed on the outer surface of the detection block 264, and an arc plate 27 is fixedly installed on the end of the adjusting plate 261 away from the detection block 264.

[0047] Specifically, when the arc plate 27 is moved by force, the adjustment plate 261 fixed on the arc plate 27 is driven to move, and at the same time the adjustment plate 261 slides on the detection block 264, thereby recording the expansion or contraction of the concrete.

[0048] Furthermore, a groove 265 is provided on one side of the detection block 264 , and a detection member 266 is provided on the inner wall of the groove 265 . The end of the detection member 266 away from the detection block 264 is connected to the adjustment plate 261 , and an elastic member 267 is sleeved on the outer surface of the detection member 266 .

[0049] Specifically, detection member 266 is a device with expansion and contraction detection capabilities, such as a pressure sensor, and is connected to an external control device. When the adjustment plate 261 moves, it squeezes and slides the detection member 266, which is located within the inner cavity of the detection block 264, and transmits the movement data in real time to the control device to record the time point of concrete expansion or contraction. A temperature detector can also be installed on one side of the control device to record the temperature in the current environment. After the detection member 266 records the data, the current environmental problem is also recorded, facilitating subsequent judgment of the expansion or contraction of concrete under different temperature environments. Elastic member 267 is an elastic component, such as a spring, used to provide power to restore the adjustment plate 261 to its initial position after movement.

[0050] A corresponding control device can be provided for use in conjunction with the electronic components of this application. This control device can be connected to any controller and thereby control the opening and closing of each component. This is prior art, and a single-chip microcomputer can be provided as the control device for demonstration purposes. The single-chip microcomputer in this embodiment is a typical embedded microcontroller (MCU), consisting of an arithmetic unit, a controller, memory, and input / output devices, equivalent to a miniature computer. Compared to the general-purpose microprocessors used in personal computers, it emphasizes self-sufficiency (no external hardware required) and cost savings. Its greatest advantages are its small size, allowing it to be placed inside an instrument, low storage capacity, simple input / output interfaces, and low power consumption.

[0051] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A device for testing the volume deformation of large-volume concrete, characterized in that: The protective tube (1) comprises a connecting block (11) provided in the inner cavity of the protective tube (1), a positioning rod (12) provided at the upper end of the connecting block (11), and a detection component (2) provided at the upper end of the positioning rod (12), and the volume deformation of the concrete is monitored by the detection component (2); The detection assembly (2) includes a gear (21), a positioning block (24) is provided at the middle position of the lower end of the gear (21), and a support plate (25) is fixedly installed at the lower end of the positioning block (24), the longitudinal section of the support plate (25) is pentagonal, and an adjusting member (26) is slidably installed on the inner wall of each end of the support plate (25), and a vertical rod (28) is provided at the lower end of each of the two adjacent vertical rods (28) of the adjusting member (26), and a flexible plate (29) is provided on the outer surface of the vertical rod (28) provided at the lower end of each of the two adjacent adjusting members (26); One end of the gear (21) is provided with a plurality of arc grooves (22), and the plurality of arc grooves (22) are evenly distributed on one end of the gear (21), and a slider (23) is slidably mounted on the inner wall of each arc groove (22); The adjusting member (26) includes a movable plate (262), and the upper end of the movable plate (262) is fixedly connected to the lower end of the slider (23); A clamping block (263) is provided in the inner cavity at one end of the movable plate (262), and a detection block (264) is rotatably mounted at one end of the clamping block (263); An adjustment plate (261) is slidably mounted on the outer surface of the detection block (264), and an arc-shaped plate (27) is fixedly mounted on one end of the adjustment plate (261) away from the detection block (264); A transmission block (211) is provided at the upper end of the support plate (25) and on one side of the gear (21), and the outer surface of the transmission block (211) is meshed with the outer surface of the gear (21).

2. A volume deformation testing device for mass concrete according to claim 1, characterized in that: A groove (265) is provided on one side of the detection block (264), and a detection member (266) is provided on the inner wall of the groove (265). An end of the detection member (266) away from the detection block (264) is connected to the adjustment plate (261), and an elastic member (267) is sleeved on the outer surface of the detection member (266).

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