Concrete shrinkage test equipment under low-temperature construction condition

Abstract

The invention relates to the technical field of shrinkage tests, in particular to concrete shrinkage test equipment under a low-temperature construction condition, which comprises a concrete shrinkage test bench, the bottom of the concrete shrinkage test bench is rotatably connected with a support base, and the bottom of the support base is provided with a moving assembly. The driving mechanism is used for driving the supporting base and the concrete shrinkage test bench to move linearly in the same direction, and the self-adaptive measuring mechanism is arranged between the side face and the top of the concrete shrinkage test bench and distributed in an L shape. The self-adaptive measuring mechanism comprises a lifting type track drawing assembly arranged on the side face of the concrete shrinkage test bed and a transverse moving type track drawing assembly arranged on the top of the concrete shrinkage test bed, the lifting type track drawing assembly and the transverse moving type track drawing assembly are the same in structure and are distributed in an L shape, and a power transmission part is arranged at the connecting end of the lifting type track drawing assembly and the transverse moving type track drawing assembly. The equipment can perform automatic high-precision measurement on concrete, and meanwhile, the measurement result is visual and convenient for accurate comparison.

Description

Technical Field

[0001] The invention relates to the technical field of shrinkage testing, in particular to a concrete shrinkage testing device under low-temperature construction conditions. Background Art

[0002] High-rise buildings are favored by builders because of their high land utilization rate, promotion of scientific and technological progress, and significant improvement of the city's image. Due to the construction period, the shear wall structure concrete cannot be cured for a long time with formwork, and the vertical suspended shear wall concrete is usually exposed to the air due to the difficulty of curing after demolding. The cold and windy environment in the cold winter in northern my country poses a huge challenge to the concrete curing of super high-rise buildings. Shear walls are often affected by the large temperature difference between the inside and outside and the strong wind, which causes harmful cracks. This phenomenon is more common in super high-rise buildings in the cold northern regions and has a serious impact on the quality of the building. The concrete shrinkage test device under low-temperature construction conditions specifically simulates the northern climate environment to test the shrinkage performance of concrete test blocks to ensure the quality of the project.

[0003] The existing patent authorization number is: CN213023150U, which discloses a concrete shrinkage test device under low-temperature construction conditions, including an outer frame, a support rod is provided at the bottom inner side of the outer frame, a telescopic platform is provided on the upper end surface of the support rod, a telescopic rod is provided on the upper end surface of the telescopic platform, a sample placement groove is provided at the top of the telescopic rod, a baffle is provided on the sample placement groove, a fixing rod is provided at the junction of the inclined groove and the sample placement groove, a soil collection container is provided at the other end of the inclined groove, a heating resistor is provided on the inner side wall of the outer frame, a power supply is provided on the outer side wall of the outer frame, a detector is provided at the top of the outer frame, a pressure sensor is provided on the lower end surface of the detector, a spring is provided on the lower end surface of the pressure sensor, a pressure plate is connected to the other end of the spring, a blowing device is provided on the side wall of the outer frame, a blower is provided inside the blowing device, a refrigeration plate is provided at the front end of the blower, a guide plate is provided at the front end of the refrigeration plate, a box door is provided on the front of the outer frame, and a handle is provided on the box door. After analyzing the device, it can be found that it has the following problems: when testing concrete, it is impossible to detect the shrinkage size change of concrete in real time, and it is also impossible to fully detect the surface of concrete. At the same time, in most cases, the measurement needs to be performed manually with the help of measuring tools, which is slow, inefficient, and not intuitive enough;

[0004] Therefore, in view of the above-mentioned problems, the present technical solution proposes a concrete shrinkage test device under low temperature construction conditions. Summary of the invention

[0005] The purpose of the present invention is to provide a concrete shrinkage test device under low temperature construction conditions to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a concrete shrinkage test device under low-temperature construction conditions, comprising a concrete shrinkage test bench, on which concrete to be subjected to a low-temperature shrinkage test is placed for a positioning test; a support base is rotatably connected to the bottom of the concrete shrinkage test bench, the concrete shrinkage test bench can rotate relative to the support base, and a moving component is installed at the bottom of the support base for driving the support base and the concrete shrinkage test bench to run linearly in the same direction;

[0007] The adaptive measuring mechanism is arranged between the side and the top of the concrete shrinkage test bench and is distributed in an L shape. With the movement of the concrete shrinkage test bench, the low-temperature shrinkage test changes of the top and the side of the concrete are covered and moved. The adaptive measuring mechanism includes a lifting trajectory drawing component arranged on the side of the concrete shrinkage test bench and a transverse trajectory drawing component arranged on the top of the concrete shrinkage test bench. The lifting trajectory drawing component and the transverse trajectory drawing component have the same structure and are distributed in an L shape. At the same time, a power transmission component is arranged at the connecting end of the two. That is, under the action of the power transmission component, the kinetic energy in the lifting trajectory drawing component is transmitted to the transverse trajectory drawing component, so as to keep the two running synchronously, and perform shrinkage change trajectory drawing measurement on the side and top surface of the concrete;

[0008] The lifting trajectory drawing component includes a lead screw arranged at a vertical interval on the side of the concrete shrinkage test bench, the top of the lead screw is rotatably connected to the transverse trajectory drawing component through a power transmission member, the bottom of the lead screw is connected to a servo motor through a connecting rod, a group of nuts are threadedly connected to the lead screw, and a guide device for limiting its rotation is provided on the nut. The servo motor is started to drive the connecting rod to drive the lead screw to rotate, thereby controlling the nut to move up and down along the lead screw. An adaptive elastic drawing member is provided on the nut, one end of the adaptive elastic drawing member is set as a rolling end, the rolling end is in rolling contact with the concrete surface, and the other end is set as a trajectory drawing end. The trajectory drawing end draws a corresponding moving trajectory according to the moving path of the rolling contact, that is, according to the low-temperature shrinkage test changes of the concrete, the outer surface is moved and measured multiple times, and the drawn moving trajectory changes are compared, so as to accurately measure the low-temperature shrinkage test data of the concrete;

[0009] When the adaptive elastic drawing part rolls along the concrete surface, its contact measurement area each time is limited, so it needs to perform multiple reciprocating measurements along the vertical height or horizontal distance. Each movement measurement corresponds to a moving track, which causes the track drawing end to change a new drawn area each time. At this time, an automatic transfer part is provided at the track drawing end. The automatic transfer part is used to control the track drawing end. Each time the rolling end is lifted or moved laterally, the track drawing end is synchronously controlled to move to a new drawn area, so as to keep the tracks between each height or width from affecting each other. The automatic transfer part is respectively connected to the corresponding driving ends of the lifting track drawing component and the moving track drawing component, that is, its movement is kept synchronous with the lifting or moving of the nut, so as to realize adaptive synchronous change.

[0010] That is, by setting a lifting trajectory drawing component and a lateral trajectory drawing component on the side and top of the concrete shrinkage test bench, in coordination with the linear movement of the concrete shrinkage test bench, a fully intuitive low-temperature test shrinkage change measurement and recording of the concrete outer surface can be achieved.

[0011] Compared with the prior art, the beneficial effects of the present invention are: by setting two sets of lifting trajectory drawing components and the lateral trajectory drawing components to be rotatably connected, respectively placed on the side and top of the concrete, and then reciprocating to avoid rolling path drawing on the outside of the concrete, the dimensional changes before and after the low-temperature shrinkage test of the concrete can be accurately and intuitively observed, and compared with simple single dimensional measurement, it has the advantages of high measurement accuracy and sufficient measurement;

[0012] By rotatably connecting the lifting trajectory drawing component with the transverse trajectory drawing component, it is possible to control the synchronous operation of the two groups of components under the premise of a single motor, and in the process of operation, the drawing pen is controlled by the automatic transfer part to perform adaptive position switching, ensuring that when measuring the outside of the concrete, each height or each length position can be accurately and independently drawn. While achieving sufficient measurement, the degree of connection between the entire equipment structure can be fully reduced, thereby reducing the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a three-dimensional structural schematic diagram of a concrete shrinkage test equipment under low-temperature construction conditions;

[0014] Figure 2 It is a schematic diagram of the main structure of a concrete shrinkage test equipment under low-temperature construction conditions;

[0015] Figure 3 It is a top view structural schematic diagram of a concrete shrinkage test equipment under low temperature construction conditions;

[0016] Figure 4 for Figure 3A is a schematic diagram of the enlarged structure of the middle part;

[0017] Figure 5 for Figure 1 Schematic diagram of the enlarged structure of B;

[0018] Figure 6 for Figure 1 Schematic diagram of the enlarged structure of C in the middle;

[0019] Figure 7 for Figure 1 Schematic diagram of the enlarged structure of D in the middle;

[0020] Figure 8 for Figure 2 Schematic diagram of the enlarged structure of E;

[0021] Wherein: concrete shrinkage test bench 10, support base 11, movable track 12, slide rail 13, power device 14, angle adjustment motor 15, support column 16, rectangular groove 17, rectangular positioning plate 19, servo motor 21, lead screw 22, nut 23, shrinkage trajectory drawing board 24, ball 25, bracket 26, connecting plate 27, buffer spring 28, buffer rod 29, plate cylinder 30, rack 31, length adjustment piece 32, drawing pen 33, clamp ring 34, transmission belt I 35, bevel gear III 36, bevel gear IV 37, bevel gear II 38, bevel gear I 39, transmission rod 40, transmission belt II 41, connecting shaft 42, bevel gear V 43, bevel gear VI 44, fixing block 45, shaft seat 46, gear rod 47, transmission belt III 49, bevel gear VII 50. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0026] See also Figure 1-Figure 3 A concrete shrinkage test device under low-temperature construction conditions includes a concrete shrinkage test bench 10, on which concrete to be subjected to a low-temperature shrinkage test is placed for a positioning test; a support base 11 is rotatably connected to the bottom of the concrete shrinkage test bench 10, the concrete shrinkage test bench 10 can rotate relative to the support base 11, and a moving component is installed at the bottom of the support base 11 for driving the support base 11 and the concrete shrinkage test bench 10 to run linearly in the same direction;

[0027] The adaptive measuring mechanism is arranged between the side and the top of the concrete shrinkage test bench 10 and is distributed in an L shape. With the movement of the concrete shrinkage test bench 10, the low-temperature shrinkage test changes of the top and the side of the concrete are covered and moved. The adaptive measuring mechanism includes a lifting trajectory drawing component arranged on the side of the concrete shrinkage test bench 10 and a transverse trajectory drawing component arranged on the top of the concrete shrinkage test bench 10. The lifting trajectory drawing component and the transverse trajectory drawing component have the same structure and are distributed in an L shape. At the same time, a power transmission component is arranged at the connecting end of the two. That is, under the action of the power transmission component, the kinetic energy in the lifting trajectory drawing component is transmitted to the transverse trajectory drawing component, so as to keep the two running synchronously, and perform shrinkage change trajectory drawing measurement on the side and top surface of the concrete;

[0028] The lifting trajectory drawing component includes a lead screw 22 arranged at a vertical interval on the side of the concrete shrinkage test bench 10. The top of the lead screw 22 is rotatably connected to the transverse trajectory drawing component through a power transmission member. The bottom of the lead screw 22 is connected to a servo motor 21 through a connecting rod. A group of nuts 23 are threadedly connected to the lead screw 22. The nut 23 is provided with a guide device for limiting its rotation. The servo motor 21 is started to drive the connecting rod to drive the lead screw 22 to rotate, thereby controlling the nut 23 to move up and down along the lead screw 22. An adaptive elastic drawing member is provided on the nut 23. One end of the adaptive elastic drawing member is set as a rolling end, and the rolling end is in rolling contact with the concrete surface. The other end is set as a trajectory drawing end. The trajectory drawing end draws a corresponding moving trajectory according to the moving path of the rolling contact, that is, according to the low-temperature shrinkage test changes of the concrete, its outer surface is moved and measured multiple times, and the drawn moving trajectory changes are compared, so as to accurately measure the low-temperature shrinkage test data of the concrete.

[0029] When the adaptive elastic drawing member rolls along the concrete surface, its contact measurement area each time is limited, so it needs to perform multiple reciprocating measurements along the vertical height or horizontal distance. Each movement measurement corresponds to a moving track, which causes the track drawing end to change a new drawn area each time. At this time, an automatic transfer member is provided at the track drawing end. The automatic transfer member is used to control the track drawing end. Each time the rolling end is lifted or moved laterally, the track drawing end is synchronously controlled to move to a new drawn area, so as to keep the tracks between each height or width from affecting each other. The automatic transfer member is rotatably connected to the driving ends of the corresponding lifting track drawing components and the lateral track drawing components, that is, its movement is kept synchronous with the lifting or lateral movement of the nut 23, so as to achieve adaptive synchronous change.

[0030] That is, by arranging a lifting track drawing component and a lateral track drawing component on the side and top of the concrete shrinkage test bench 10, in coordination with the linear movement of the concrete shrinkage test bench 10, a fully intuitive low-temperature test shrinkage change measurement and recording of the concrete outer surface is achieved;

[0031] At the same time, during actual use, since concrete has multiple outer surfaces, the number and position of the lifting trajectory drawing components and the horizontal movement trajectory drawing components can be set according to actual conditions without changing the basic operating premise and distance of the equipment.

[0032] In the embodiment of the present invention, refer to Figure 4 A rectangular groove 17 is provided on the top of the concrete shrinkage test bench 10, and a plurality of rectangular positioning plates 19 are evenly installed on the inner wall of the rectangular groove 17. A hydraulic cylinder is connected to the side of the rectangular positioning plate 19 facing the inner wall of the rectangular groove 17. The hydraulic cylinder is activated to control the movement of the rectangular positioning plate 19, so that the concrete placed in the rectangular groove 17 is stably fixed;

[0033] See also Figure 8 A group of angle adjustment motors 15 fixed on the support base 11 are connected to the middle of the bottom of the concrete shrinkage test bench 10. The angle adjustment motor 15 is used to adjust the placement angle of the concrete shrinkage test bench 10, so as to adjust the measurement surface of the concrete in the rectangular groove 17. At the same time, in order to increase the stability of the rotation support between the concrete shrinkage test bench 10 and the support base 11, a plurality of support columns 16 are installed on the support base 11 around the angle adjustment motor 15. A circle of slide grooves are provided at the bottom of the concrete shrinkage test bench 10 corresponding to the top of the support column 16. The top of the support column 16 rotates along the slide groove to play a supporting role;

[0034] The moving assembly includes slide rails 13 fixed on both sides of the bottom of the support base 11, and the bottom of the slide rails 13 is slidably connected with a moving track 12. A power device 14 is provided at the bottom of the support base 11 on one side of the slide rail 13. With the cooperation of the power device 14, the slide rails 13 and the moving track 12, the support base 11 is controlled to reciprocate along the support base 11 to realize the mobile measurement test of the concrete in the rectangular groove 17.

[0035] In one embodiment of the present invention, the lengths of the vertically distributed lead screws 22 and the horizontally distributed lead screws 22 are both greater than the height and length of the concrete, ensuring that the side surface of the concrete can be fully measured.

[0036] As a preferred embodiment of the present invention, refer to Figure 5 , Figure 6 , a group of balls 25 are arranged at the rolling end, and the balls 25 are in rolling contact with the outer surface of the concrete to be measured, and brackets 26 of U-shaped structure are arranged on both sides of the balls 25, and a connecting plate 27 is fixedly installed at the end of the bracket 26, and the side of the connecting plate 27 away from the balls 25 is elastically connected to the side of the nut 23 through the buffer spring 28, and two groups of buffer rods 29 that can move through the nut 23 are symmetrically installed on the connecting plates 27 on both sides of the buffer spring 28, and the ends of the two groups of buffer rods 29 are connected to the track drawing end together, that is, the rolling path of the balls 25 on the outer wall of the concrete and the elastic effect of the buffer spring 28 are utilized to drive the track drawing end to automatically draw the running track;

[0037] The track drawing end includes a plate tube 30 installed at the ends of two groups of buffer rods 29, a group of racks 31 are telescopically arranged inside the plate tube 30, the ends of the racks 31 are connected to length adjustment members 32, the ends of the length adjustment members 32 are installed with clamping rings 34, a drawing pen 33 parallel to the corresponding concrete outer wall is clamped and installed inside the clamping ring 34, a contraction track drawing board 24 is contact-distributed at the end of the drawing pen 33, the contraction track drawing board 24 and the drawing pen 33 are in a vertical distribution state, that is, when the buffer rod 29 is elastically telescopically moved, the drawing pen 33 is synchronously driven to slide on the contraction track drawing board 24, so as to draw the corresponding concrete contraction change;

[0038] A gear rod 47 is provided at one side of the end of the plate tube 30, and the gear rod 47 is meshed and connected with the rack 31. Gear rods are installed at both ends of the gear rod 47, and the gear rod is positioned on the plate tube 30 through a supporting sleeve rod. One end of the gear rod is connected to an automatic transfer member, and the rack 31 is driven to move along the plate tube 30 inside and outside by rotating the gear rod 47, so as to adjust the position of the drawing pen 33, that is, when measuring the concrete outer wall at different heights or horizontal positions, the drawing pen 33 can draw a track in the new drawing area on the shrinkage track drawing board 24;

[0039] The length adjusting member 32 is composed of two sets of screws and one set of screw barrels. The two sets of screws are respectively threadedly connected to the two ends of the screw barrels. The ends of the screws away from the screw barrels are respectively fixedly connected to the clamping ring 34 and the rack 31. That is, by rotating the screw barrels, the lengths of the screws at the two ends are adjusted, thereby adjusting the initial position of the drawing pen 33.

[0040] Specifically, the clamp ring 34 is composed of two sets of semicircular rings hinged together, and cooperates with bolts and other structures to stably clamp the drawing pen 33;

[0041] The drawing pen 33 is generally a ballpoint pen, which can be stably moved and drawn on the contraction track drawing board 24 .

[0042] As a preferred embodiment of the present invention, the power transmission member includes a connecting shaft 42 fixed to the top of the lead screw 22 in the lifting trajectory drawing component, a bevel gear V43 is installed on the top of the connecting shaft 42, a bevel gear VI44 is vertically meshed on one side of the bevel gear V43, a horizontal transmission rod is installed in the middle of the bevel gear VI44, and one end of the transmission rod is fixedly connected to the end of the lead screw 22 in the transverse trajectory drawing component, that is, under the connection of the connecting shaft 42, the bevel gear V43, the bevel gear VI44 and the transmission rod, the purpose of transmitting the kinetic energy of the servo motor 21 to the transverse trajectory drawing component for operation is achieved;

[0043] A set of shaft seats 46 are movably provided in the middle of the connecting shaft 42, and a set of fixed blocks 45 are installed on one side of the shaft seat 46 through an L-shaped connecting rod. The end of the transmission rod in the transverse trajectory drawing component away from the screw 22 is rotatably connected in the fixed block 45, that is, the stable operation of the transverse trajectory drawing component is maintained by the fixed block 45.

[0044] See also Figure 7 The automatic transfer part includes a transmission belt I35 rotatably connected to the gear rod. The end of the transmission belt I35 in the transverse trajectory drawing component is connected to a group of transmission belts II41 that rotate downward obliquely. The transmission belt II41 is connected to a transmission belt III49 that rotates toward one side of the bevel gear V43. The end of the transmission belt III49 is connected to a group of bevel gears VII50 that mesh with the bevel gear V43, that is, the bevel gear V43 drives the bevel gear VII50 to rotate, and then drives the gear rod 47 to rotate under the transmission of the transmission belt III49, the transmission connecting rod 40 and the transmission belt I35, so as to control the position transfer of the drawing pen 33, that is, each time the lead screw 22 in the transverse trajectory drawing component is controlled to rotate and the corresponding ball 25 is controlled to move along the top of the concrete, the corresponding position of the drawing pen 33 is transferred once;

[0045] Similarly, a bevel gear I39 is installed on the connecting rod in the lifting trajectory drawing component, and a bevel gear II38 is vertically meshed on one side of the bevel gear I39, and a bevel gear IV37 is connected to one side of the bevel gear II38, and a bevel gear III36 is vertically meshed on one side of the bevel gear IV37, and a gear rod on one side of the bevel gear III36 is rotatably connected to the transmission belt I35, that is, under the transmission of the bevel gear I39, the bevel gear II38, the bevel gear IV37, the bevel gear III36, and the transmission belt I35, each time the ball 25 in the lifting trajectory drawing component is lifted and lowered, the corresponding drawing pen 33 switches its position once, so as to maintain accurate trajectory drawing of the outer side of the concrete at each height.

[0046] The working principle of the present invention is: in the idle position of the device, all the driving parts mentioned above, which refer to power elements, electrical components and adapted power supplies, are connected through wires, and the electrical connections are completed in a sequential working order between the electrical components. The detailed connection means are well-known technologies in the art. The following mainly introduces the working principle and process, and does not explain the electrical control. During operation, the concrete before and after low-temperature treatment is placed in the rectangular groove 17 on the concrete shrinkage test bench 10, and then before the test, the side top of the concrete shrinkage test bench 10 is covered with trajectory mapping measurement by the lifting trajectory mapping component and the lateral trajectory mapping component, and then the data is recorded. After the concrete is placed in a low-temperature environment for a period of time, it is placed in the rectangular groove 17 again, and then the side top of the concrete shrinkage test bench 10 is covered with trajectory mapping measurement again by the lifting trajectory mapping component and the lateral trajectory mapping component. The trajectories drawn twice are compared, and then the data difference is calculated, so as to accurately obtain the shrinkage of the concrete low-temperature test. The measurement process of the concrete surface has been described in detail above.

[0047] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A concrete shrinkage test equipment under low temperature construction conditions, characterized in that: The concrete shrinkage test bench (10) comprises a concrete shrinkage test bench (10), wherein the bottom of the concrete shrinkage test bench (10) is rotatably connected to a support base (11), and a moving component is installed at the bottom of the support base (11) for driving the support base (11) and the concrete shrinkage test bench (10) to move linearly in the same direction; An adaptive measuring mechanism is arranged between the side and the top of the concrete shrinkage test bench (10) and is arranged in an L-shape. The adaptive measuring mechanism comprises a lifting track drawing component arranged on the side of the concrete shrinkage test bench (10) and a transverse track drawing component arranged on the top of the concrete shrinkage test bench (10). The lifting track drawing component and the transverse track drawing component have the same structure and are arranged in an L-shape. A power transmission member is arranged at the connection end of the two. The lifting trajectory drawing component comprises a lead screw (22) vertically arranged at intervals on the side of the concrete shrinkage test bench (10); the top of the lead screw (22) is rotatably connected to the transverse trajectory drawing component through a power transmission member; the bottom of the lead screw (22) is connected to a servo motor (21) through a connecting rod; a group of nuts (23) are threadedly connected to the lead screw (22); the nuts (23) are provided with a guide device for limiting their rotation; an adaptive elastic drawing member is provided on the nut (23); one end of the adaptive elastic drawing member is provided as a rolling end, the rolling end is in rolling contact with the concrete surface, and the other end is provided as a trajectory drawing end; the trajectory drawing end draws a corresponding moving trajectory according to the moving path of the rolling contact; according to the low-temperature shrinkage test changes of the concrete, the outer surface is subjected to multiple movement measurements, and the drawn moving trajectory changes are compared, so as to accurately measure the low-temperature shrinkage test data of the concrete; The trajectory drawing end is provided with an automatic transfer part, which is used to control the trajectory drawing end. Each time the rolling end is lifted or moved laterally, the trajectory drawing end is synchronously controlled to move to a new drawn area. The automatic transfer part is rotationally connected to the driving ends of the corresponding lifting trajectory drawing components and the transverse trajectory drawing components.

2. The concrete shrinkage test equipment under low temperature construction conditions according to claim 1, characterized in that: A rectangular groove (17) is provided on the top of the concrete shrinkage test bench (10), a plurality of groups of rectangular positioning plates (19) are evenly installed on the inner wall of the rectangular groove (17), and a hydraulic cylinder is connected to the side of the rectangular positioning plates (19) facing the inner wall of the rectangular groove (17).

3. The concrete shrinkage test equipment under low temperature construction conditions according to claim 2, characterized in that: A group of angle adjustment motors (15) fixed on a support base (11) are connected to the middle of the bottom of the concrete shrinkage test bench (10); a plurality of support columns (16) are installed on the support base (11) around the angle adjustment motor (15); a circle of slide grooves are provided at the bottom of the concrete shrinkage test bench (10) corresponding to the tops of the support columns (16); and the tops of the support columns (16) rotate along the slide grooves.

4. The concrete shrinkage test equipment under low temperature construction conditions according to claim 3, characterized in that: The moving assembly comprises slide rails (13) fixed on both sides of the bottom of the support base (11); the bottom of the slide rails (13) is correspondingly slidably connected to a moving track (12); and a power device (14) is provided at the bottom of the support base (11) on one side of the slide rails (13).

5. The concrete shrinkage test equipment under low temperature construction conditions according to claim 4, characterized in that: The rolling end is provided with a group of balls (25), the balls (25) are in rolling contact with the outer surface of the concrete to be measured, and brackets (26) of U-shaped structures are rollingly provided on both sides of the balls (25). A connecting plate (27) is fixedly installed at the end of the bracket (26), and the side of the connecting plate (27) away from the balls (25) is elastically connected to the side of the nut (23) through a buffer spring (28). Two groups of buffer rods (29) that movably pass through the nuts (23) are symmetrically installed on the connecting plates (27) on both sides of the buffer spring (28), and the ends of the two groups of buffer rods (29) are commonly connected to the track drawing end.

6. The concrete shrinkage test equipment under low temperature construction conditions according to claim 5, characterized in that: The track drawing end comprises a plate tube (30) mounted at the ends of two groups of buffer rods (29), a group of racks (31) are telescopically arranged inside the plate tube (30), the ends of the racks (31) are connected to a length adjustment member (32), a clamping ring (34) is mounted at the end of the length adjustment member (32), a drawing pen (33) parallel to the corresponding concrete outer wall is clamped and mounted inside the clamping ring (34), a contraction track drawing board (24) is contact-distributed at the end of the drawing pen (33), and the contraction track drawing board (24) and the drawing pen (33) are in a vertically distributed state.

7. The concrete shrinkage test equipment under low temperature construction conditions according to claim 6, characterized in that: A gear rod (47) is provided at one side of the end of the plate cylinder (30), the gear rod (47) is meshed with the rack (31), gear rods are installed at both ends of the gear rod (47), the gear rod is positioned on the plate cylinder (30) through a supporting sleeve rod, and one end of the gear rod is connected to the automatic transfer component.

8. The concrete shrinkage test equipment under low temperature construction conditions according to claim 7, characterized in that: The power transmission member comprises a connecting shaft (42) fixed to the top of a lead screw (22) in a lifting trajectory drawing component, a bevel gear V (43) is mounted on the top of the connecting shaft (42), a bevel gear VI (44) is vertically meshed on one side of the bevel gear V (43), a horizontal transmission rod is mounted in the middle of the bevel gear VI (44), and one end of the transmission rod is fixedly connected to the end of the lead screw (22) in the transverse trajectory drawing component; A set of shaft seats (46) are movably arranged in the middle of the connecting shaft (42), a set of fixed blocks (45) are installed on one side of the shaft seat (46) via an L-shaped connecting rod, and the end of the transmission rod in the transverse trajectory drawing component away from the lead screw (22) is rotatably connected in the fixed block (45).

9. The concrete shrinkage test equipment under low temperature construction conditions according to claim 8, characterized in that: The automatic transfer component comprises a transmission belt I (35) rotatably connected to the gear rod, the end of the transmission belt I (35) in the transverse track drawing component is rotatably connected to a group of transmission belts II (41) in a downwardly oblique manner, the transmission belt II (41) is rotatably connected to a side of the bevel gear V (43) by a transmission belt III (49), and the end of the transmission belt III (49) is connected to a group of bevel gears VII (50) meshing with the bevel gear V (43).

10. The concrete shrinkage test equipment under low temperature construction conditions according to claim 9, characterized in that: A bevel gear I (39) is installed on the connecting rod of the lifting trajectory drawing component, one side of the bevel gear I (39) is vertically meshed with a bevel gear II (38), one side of the bevel gear II (38) is connected to a bevel gear IV (37), one side of the bevel gear IV (37) is vertically meshed with a bevel gear III (36), and a gear rod on one side of the bevel gear III (36) is rotatably connected to a transmission belt I (35).

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