A high ductility shotcrete resilience testing device

Abstract

The utility model discloses a kind of high ductility shotcrete rebound rate testing devices, belong to building material performance test technical field, the device includes pedestal, first weighing unit, second weighing unit, aggregate component and base plate component, the first weighing unit is for carrying and sensing the weight of base plate component and concrete attached on it, the second weighing unit is for carrying and sensing the weight of aggregate component and rebound concrete in it, base plate component is connected with angle adjusting mechanism by transmission shaft, can simulate vertical, elevation angle and depression angle and other multiple spray working conditions, and experimental base plate surface can replace veneer, to simulate different base conditions, aggregate component adopts bucket shape structure and is equipped with anti-adhesion layer and vibrator, ensure that rebound material collection and cleaning are smooth, controller and two weighing sensors are electrically connected, can automatically collect data and accurately calculate rebound rate, the utility model realizes the efficient, accurate and standardized test to high ductility shotcrete rebound performance.

Description

Technical Field

[0001] This utility model belongs to the field of building material construction performance testing technology, specifically relating to a high-ductility shotcrete rebound rate testing device. Background Technology

[0002] Shotcrete is a concrete construction technology that involves transporting concrete through pipelines and spraying it at high speed onto the surface of a structure. It is now widely used in engineering fields such as tunnel support, slope reinforcement, and building repair. The rebound rate is a key indicator for evaluating the construction performance and economy of shotcrete. It refers to the ratio of the weight of concrete aggregate that bounces off the sprayed surface to the total weight of the shotcrete. A high rebound rate not only wastes materials and increases project costs, but also deteriorates the construction environment and affects the quality of support.

[0003] Currently, the main basis for determining the rebound rate of shotcrete on-site is the "Technical Specification for Shotcrete Application". This method mainly involves manually collecting the rebound material and weighing it for calculation. Specifically, before the shotcreting operation, a collection canvas or template is laid out, and after the shotcreting is completed, the rebound material is collected manually and weighed using a platform scale. The rebound rate is then calculated based on the total amount shot. Although this method is simple and easy to implement, it has obvious drawbacks: First, the collection process relies entirely on manual operation, making it difficult to avoid material leakage and loss; second, real-time monitoring during the shotcreting process cannot be achieved, and the test results are greatly affected by human factors; most importantly, this method uses a single weight measurement mode, which cannot simultaneously obtain accurate data on the adhering material and the rebound material, resulting in limited test accuracy.

[0004] With the development of materials technology, high-ductility concrete has been widely used in the field of shotcrete. This material, by incorporating special fibers into the cement matrix, has significant tensile hardening characteristics and multi-crack propagation ability. Its unique material composition and rheological properties make its rebound mechanism fundamentally different from that of traditional concrete. The bridging effect of fibers and the viscosity of the paste in high-ductility concrete will significantly affect its rebound characteristics, and existing testing methods cannot accurately reflect the influence of these material properties on the rebound rate.

[0005] Furthermore, actual engineering projects face various working conditions during spraying operations, including upward spraying of the top arch, vertical spraying of the side walls, and downward spraying of the slope, etc. Existing testing methods lack a standard substrate angle adjustment mechanism, which cannot simulate the rebound characteristics under different spraying angles, resulting in a large deviation between the test data and the actual engineering situation. At the same time, the bonding characteristics and interface behavior between high ductility concrete and the substrate are also affected by the surface texture of the substrate, while existing testing devices usually use smooth substrates, which cannot truly reflect the interaction between concrete and substrates with different roughness.

[0006] Therefore, developing a dedicated testing device that can accurately measure the rebound rate of high-ductility shotcrete, adapt to different spraying angles, consider the characteristics of the base layer interface, and achieve automatic measurement is of great significance for promoting the application of high-ductility concrete materials in shotcrete engineering, optimizing spraying process parameters, and reducing material loss. Summary of the Invention

[0007] The purpose of this invention is to provide a high-ductility shotcrete rebound rate testing device to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a high-ductility shotcrete rebound rate testing device, comprising a base, a first weighing unit, a second weighing unit, an aggregate assembly, and a base plate assembly. The first weighing unit includes a first weighing bracket, a controller, and a first weighing sensor, and is disposed on the base. The second weighing unit includes a second weighing bracket and a second weighing sensor, and is disposed on the base. The aggregate assembly is fixedly installed on the second weighing bracket. The base plate assembly includes a drive shaft, and is fixedly connected to the first weighing bracket via the drive shaft. The controller is electrically connected to the first and second weighing sensors respectively. The first weighing sensor is disposed between the first weighing bracket and the base, and is used to sense the weight of the base plate assembly and the material attached thereto. The second weighing sensor is disposed between the second weighing bracket and the base, and is used to sense the weight of the aggregate assembly and the rebound material inside it.

[0009] Preferably, the material collection assembly includes a bucket-shaped material collection trough, which is fixedly installed on the second weighing bracket, and a sealed unloading gate is provided at the bottom of the bucket-shaped material collection trough.

[0010] Preferably, the substrate assembly includes an experimental substrate, a protective cover, a drive shaft, a pin disk, a pin, pin holes, and positioning holes. The drive shaft is fixedly connected to the first weighing bracket, and the experimental substrate is rotatably connected to the drive shaft. The protective cover is fixedly connected to the experimental substrate, and the protective cover surrounds the spray area of ​​the experimental substrate. The pin disk is fixedly mounted on the drive shaft, and multiple pin holes are evenly distributed in a ring on the pin disk. Positioning holes corresponding to the pin holes are opened on the side of the protective cover. The experimental substrate and the protective cover can be rotated around the drive shaft to adjust their angle. The pin is inserted into the pin hole and the corresponding positioning hole to lock the experimental substrate, thereby simulating vertical, elevation, and depression working conditions.

[0011] Preferably, the sprayed surface of the experimental substrate is provided with a replaceable coating to simulate the working conditions of walls with different roughness or different materials.

[0012] Preferably, the inner wall of the bucket-shaped material trough is lined with an anti-adhesion material layer, and the outer wall of the bucket-shaped material trough is equipped with a vibrator.

[0013] Preferably, the controller is configured to calculate the rebound rate η using the following formula: η=[a / (a+b)]×% where a is the weight of the attached material sensed by the first weighing sensor and b is the weight of the rebound material sensed by the second weighing sensor.

[0014] Compared with the prior art, the present invention has the following beneficial effects: By setting up a first weighing unit and a second weighing unit, the weight of the concrete adhering to the substrate assembly and the weight of the rebound material in the aggregate assembly are monitored in real time, respectively, and electrically connected to the controller, realizing automatic calculation and data recording of the rebound rate. This design reduces human intervention and error, improves the accuracy and reliability of test results, and provides precise data support for optimizing concrete formulation and construction technology.

[0015] The base plate assembly features an adjustable angle design. Through the cooperation of the drive shaft, pin plate, and pin, it can easily simulate different spraying conditions such as vertical, elevation, and depression angles. This allows the testing device to closely resemble actual construction conditions, comprehensively evaluate the rebound performance of concrete at different spraying angles, thereby guiding parameter settings on the construction site and reducing material waste.

[0016] The test substrate has a replaceable coating on its sprayed surface, which can simulate wall conditions with different roughness or materials. This feature allows users to flexibly adjust the test conditions according to actual engineering needs and obtain more comprehensive rebound rate data.

[0017] The material collection assembly adopts a bucket-shaped collection trough design with a sealed discharge door at the bottom, facilitating the rapid collection and cleaning of rebound material and improving testing efficiency. Simultaneously, the inner wall of the bucket-shaped collection trough is lined with an anti-adhesion material layer, and an external vibrator is installed to effectively prevent concrete adhesion and ensure complete discharge of rebound material. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall front structure of this utility model; Figure 2 This is a schematic diagram of the material collection component structure of this utility model; Figure 3 For the present utility model Figure 1 Schematic diagram of the structure at point A; Figure 4 This is a schematic diagram of the side structure of the protective cover of this utility model; Figure 5 This is a schematic diagram of the substrate assembly structure of this utility model.

[0019] In the figure: 1. Base; 2. First weighing unit; 201. First weighing bracket; 202. Controller; 203. First weighing sensor; 3. Second weighing unit; 301. Second weighing bracket; 302. Second weighing sensor; 4. Material collection assembly; 401. Bucket-shaped material collection trough; 402. Sealed unloading gate; 403. Vibrator; 5. Base plate assembly; 501. Experimental base plate; 502. Protective cover; 503. Drive shaft; 504. Pin plate; 505. Pin; 506. Pin hole; 507. Positioning hole. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0021] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0024] Please see Figure 1-5An embodiment of this utility model is provided: 1. A high-ductility shotcrete rebound rate testing device, comprising a base 1, a first weighing unit 2, a second weighing unit 3, an aggregate assembly 4, and a base plate assembly 5. The first weighing unit 2 includes a first weighing bracket 201, a controller 202, and a first weighing sensor 203, and is disposed on the base 1. The second weighing unit 3 includes a second weighing bracket 301 and a second weighing sensor 302, and is disposed on the base 1. The aggregate assembly 4 is fixedly installed on the second weighing bracket 301. The base plate assembly 5 includes a drive shaft 503, and is fixedly connected to the first weighing bracket 201 via the drive shaft 503. The controller 202 is respectively connected to... The first weighing sensor 203 and the second weighing sensor 302 are electrically connected. The first weighing sensor 203 is disposed between the first weighing bracket 201 and the base 1 and is used to sense the weight of the substrate assembly 5 and the material attached to it. The second weighing sensor 302 is disposed between the second weighing bracket 301 and the base 1 and is used to sense the weight of the aggregate assembly 4 and the rebound material inside it. This forms the core measurement framework of the device. Through the separate first and second weighing units, the device can collect two key data points in real time, synchronously and accurately: the weight of the concrete sprayed onto the substrate and the weight of the concrete rebounding into the aggregate assembly. These data are then transmitted to the controller, providing a basis for automatically calculating the rebound rate and ensuring the accuracy and objectivity of the test results.

[0025] Specifically, the material collection assembly 4 includes a bucket-shaped material collection trough 401, which is fixedly installed on the second weighing bracket 301. A sealed discharge door 402 is provided at the bottom of the bucket-shaped material collection trough 401. This design optimizes the collection and processing of rebound material. The bucket-shaped structure facilitates the collection of all rebound material, while the sealed discharge door at the bottom allows for the quick and thorough discharge of rebound material for weighing or cleaning after each test, improving testing efficiency.

[0026] Specifically, the substrate assembly 5 includes an experimental substrate 501, a protective cover 502, a drive shaft 503, a pin plate 504, pins 505, pin holes 506, and positioning holes 507. The drive shaft 503 is fixedly connected to the first weighing bracket 201, and the experimental substrate 501 is rotatably connected to the drive shaft 503. The protective cover 502 is fixedly connected to the experimental substrate 501, and the protective cover 502 surrounds the spray area of ​​the experimental substrate 501. The pin plate 504 is fixedly mounted on the drive shaft 503, and multiple pin holes 506 are evenly distributed in a ring on the pin plate 504. Positioning holes 507 are provided on the side of the protective cover 502. The positioning hole 507 corresponding to the pin hole 506 allows the experimental substrate 501 and the protective cover 502 to rotate around the drive shaft 503 to adjust their angles. The pin 505 is inserted into the pin hole 506 and the corresponding positioning hole 507 to lock the experimental substrate 501, simulating vertical, elevation, and depression conditions. The angle adjustment mechanism allows users to flexibly set the spraying angle to study the impact of different conditions (such as walls and ceilings) on the rebound rate. The protective cover effectively prevents concrete from splashing out of the test area during spraying, ensuring operational safety and guiding all rebound material to the aggregate assembly, thus ensuring the integrity of data acquisition.

[0027] Specifically, the spraying surface of the experimental substrate 501 is provided with replaceable faceplates to simulate the working conditions of walls with different roughness or different materials. By changing faceplates with different surface characteristics, the effects of substrate roughness and material (such as rock, old concrete, etc.) on the adhesion performance and rebound rate of high ductility concrete can be studied, providing detailed experimental basis for optimizing the spraying process for different engineering conditions.

[0028] Specifically, the inner wall of the hopper-shaped collection trough 401 is lined with an anti-adhesion material layer, and a vibrator 403 is installed on the outer wall of the hopper-shaped collection trough 401. The anti-adhesion material layer physically reduces the adhesion between the material and the trough wall, while the vibrator actively shakes off any material that may adhere by applying external force.

[0029] Specifically, the controller 202 is configured to calculate the rebound rate η using the following formula: η=[a / (a+b)]×100%, where a is the weight of the attached material sensed by the first weighing sensor 203 and b is the weight of the rebound material sensed by the second weighing sensor 302. This achieves fully automatic and instantaneous calculation, and the result is presented directly as a percentage, which is intuitive and clear. This avoids errors that may occur during manual recording and calculation, improves the accuracy and efficiency of data processing, and makes the testing process more standardized and intelligent.

[0030] The working principle of the high-ductility shotcrete rebound rate testing device described in this utility model is as follows: Depending on the testing requirements (such as simulating a vertical wall, arched roof spraying, or sloping roof spraying), the angle is adjusted by rotating the substrate assembly (experimental substrate 501 and protective cover 502). After adjustment, the pin 505 locks the experimental substrate 501 in place. Once locked, the required replaceable surface is installed on the experimental substrate 501 to simulate a base layer with a specific roughness or material.

[0031] The device is activated, and the controller 202 controls the first weighing sensor 203 and the second weighing sensor 302 to zero, deducting the weight of the substrate assembly 5 and the aggregate assembly 4 themselves to ensure that subsequent measurements only reflect the net weight of the materials. The operator uses a spraying device to spray high-ductility concrete onto the experimental substrate 501 according to standard procedures.

[0032] Concrete adheres to the experimental substrate 501, and its weight is transmitted to the first weighing support 201 via the drive shaft 503. This weight is sensed in real-time by the first weighing sensor 203 at its bottom, and the data is continuously transmitted to the controller 202. Unattached concrete particles that rebound and fall are effectively constrained and guided by the protective cover 502, falling entirely into the bucket-shaped collection trough 401. Their weight is sensed in real-time by the second weighing sensor 302, and this data is also continuously transmitted to the controller 202. After weighing is completed, the controller 202 calculates the rebound rate, using the formula η: η = [a / (a+b)] × 100%, where a is the weight of the attached material sensed by the first weighing sensor 203, and b is the weight of the rebounded material sensed by the second weighing sensor 302.

[0033] Open the sealed discharge door 402 at the bottom of the bucket-shaped aggregate trough 401, and the rebounded concrete will be discharged under gravity. At the same time, the vibrator 403 can be started to shake off the material adhering to the anti-adhesion material layer on the inner wall through vibration, ensuring clean discharge and preparing for the next test. Remove the sprayed concrete sample from the experimental substrate 501, and perform the zeroing operation on the two weighing units again. The device is then ready for the next test.

Claims

1. A device for testing the rebound rate of high-ductility shotcrete, characterized in that: The system includes a base (1), a first weighing unit (2), a second weighing unit (3), a material collection assembly (4), and a base plate assembly (5). The first weighing unit (2) includes a first weighing bracket (201), a controller (202), and a first weighing sensor (203). The first weighing bracket (201) is mounted on the base (1). The second weighing unit (3) includes a second weighing bracket (301) and a second weighing sensor (302). The second weighing bracket (301) is mounted on the base (1). The material collection assembly (4) is fixedly installed on the second weighing bracket. On (301), the substrate assembly (5) is mounted on the first weighing bracket (201), and the controller (202) is electrically connected to the first weighing sensor (203) and the second weighing sensor (302) respectively. The first weighing sensor (203) is disposed between the first weighing bracket (201) and the base (1) for sensing the weight of the substrate assembly (5) and the material attached thereon. The second weighing sensor (302) is disposed between the second weighing bracket (301) and the base (1) for sensing the weight of the material collection assembly (4) and the rebound material inside it.

2. The high-ductility shotcrete rebound rate testing device according to claim 1, characterized in that: The material collection assembly (4) includes a bucket-shaped material collection trough (401), which is fixedly installed on the second weighing bracket (301). A sealed unloading gate (402) is provided at the bottom of the bucket-shaped material collection trough (401).

3. The high-ductility shotcrete rebound rate testing device according to claim 1, characterized in that: The substrate assembly (5) includes an experimental substrate (501), a protective cover (502), a drive shaft (503), a pin plate (504), a pin (505), a pin hole (506), and a positioning hole (507). The drive shaft (503) is fixedly connected to the first weighing bracket (201). The experimental substrate (501) is rotatably connected to the drive shaft (503). The experimental substrate (501) is fixedly connected to the protective cover (502), which surrounds the spray area of ​​the experimental substrate (501). The pin plate... (504) is fixedly mounted on the drive shaft (503). Multiple pin holes (506) are evenly distributed in a ring on the pin plate (504). Positioning holes (507) corresponding to the pin holes (506) are opened on the side of the protective cover (502). The experimental substrate (501) and the protective cover (502) can be rotated around the drive shaft (503) to adjust the angle. The pin (505) is inserted into the pin hole (506) and the corresponding positioning hole (507) to lock the experimental substrate (501) in order to simulate vertical, elevation and depression working conditions.

4. The high-ductility shotcrete rebound rate testing device according to claim 3, characterized in that: The sprayed surface of the experimental substrate (501) is provided with replaceable facing to simulate the working conditions of walls with different roughness or different materials.

5. The high-ductility shotcrete rebound rate testing device according to claim 2, characterized in that: The inner wall of the bucket-shaped material trough (401) is lined with an anti-adhesion material layer, and the outer wall of the bucket-shaped material trough (401) is provided with a vibrator (403).

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