Concrete tensile property test mold

Abstract

The utility model relates to a concrete tensile property test mold which comprises a U-shaped mold, inner side end plates and outer side end plates are arranged at the two side ends of the U-shaped mold, a pouring cavity is formed in the U-shaped mold and located between the inner side end plates, screw rods are arranged on the two side portions of the U-shaped mold, one end of each screw rod sequentially penetrates through the corresponding outer side end plate and the corresponding inner side end plate and extends into the pouring cavity, and the other end of each screw rod penetrates through the corresponding inner side end plate and the corresponding outer side end plate. A plurality of pins are fixed to the end, located in the pouring cavity, of the screw, and the other end of the screw is in threaded connection with an adjusting nut located on the outer side of the outer side end. According to the mold, accurate centering can be achieved in a concrete tensile property test, errors caused by the eccentric distance are avoided, and the stress uniformity is improved.

Description

Technical Field

[0001] The utility model relates to a concrete tensile performance test mold. Background Art

[0002] In the design and construction of concrete structures, it is of great significance to accurately evaluate the tensile properties of concrete. However, the currently widely used concrete tensile properties test methods have obvious limitations:

[0003] (1) Although the direct method, including the dog-bone specimen and the pre-embedded steel bar method, can directly measure the tensile strength of concrete and obtain relatively realistic results, the dog-bone mold test requires a large number of components, and the manufacturing process is complicated and expensive, which increases the difficulty of tensile performance testing and increases the test cost. At the same time, the pre-embedded steel bar method is difficult to ensure the precise alignment of the steel bars, which can easily lead to excessive eccentricity and affect the accuracy of the test.

[0004] (2) The indirect method measures the test data of concrete specimens under pressure or shear force, and then converts these data into tensile strength through empirical formulas. Although this method is simple to operate and low in cost, its results often deviate from the actual situation and are greatly affected by factors such as specimen shape, size, and loading method.

[0005] Patent CN 218601002 U proposes a U-shaped mold with a U-shaped groove along its length, and a pre-embedded anchoring member is connected to the groove, and the pre-embedded anchoring member and the U-shaped mold form a concrete filling groove with an opening facing upward. In this patent, by connecting the pre-embedded anchoring member in the groove, the produced concrete tensile strength test specimen has a pre-embedded anchoring member, which can effectively avoid the problem of damage to the specimen due to direct clamping. However, the use of a single end plate is prone to uneven force caused by eccentricity, and the method of transmitting force by the connecting plate cannot effectively ensure a strong and evenly distributed bonding force. Utility Model Content

[0006] The utility model aims to provide a concrete tensile performance test mold, which helps to achieve accurate centering in the concrete tensile performance test, avoids errors caused by eccentricity, and improves force uniformity.

[0007] The technical solution of the utility model is: a concrete tensile performance test mold, including a C-shaped mold, both side ends of the C-shaped mold are provided with an inner end plate and an outer end plate, a casting cavity is formed between the inner end plates in the C-shaped mold, both side parts of the C-shaped mold are provided with a screw rod with one end passing through the outer end plate and the inner end plate in sequence and extending into the casting cavity, a plurality of pins are fixed on the end of the screw rod located in the casting cavity, and the other end of the screw rod is threadedly connected with an adjusting nut located outside the outer end portion.

[0008] Furthermore, the mold is a wooden mold, and the inner end plate and the outer end plate are both wooden boards.

[0009] Furthermore, the front and rear ends of the inner end plate and the outer end plate are connected and fixed to the U-shaped mold via nails.

[0010] Furthermore, the pins are fixed on the screw rod at intervals along the axial direction of the screw rod, and the axial projections of the pins on the screw rod are evenly arranged along the circumferential direction.

[0011] Furthermore, the number of the pins is more than 3.

[0012] Furthermore, a washer sleeved on the screw rod is arranged on the end surface of the inner end plate close to the casting cavity, and the washer is threadedly connected or welded to the screw rod.

[0013] Furthermore, the washer is a steel washer.

[0014] Furthermore, the centers of the through holes or threaded holes for the screws to pass through on the inner end plates and the outer end plates on both sides of the C-shaped mold are located on the same axis.

[0015] Compared with the prior art, the utility model has the following advantages:

[0016] 1. The mold is easy to make and can be accurately aligned in the concrete tensile performance test to avoid errors caused by eccentricity. It also has the advantages of simple manufacturing and low cost.

[0017] 2. There are two end plates on both sides, and a coaxial through hole is set in the center of the end plate. The screw passes through the through holes of the two layers of end plates to align the axial direction of the specimen to ensure the axial force, thus avoiding the problem of uneven force caused by eccentricity caused by using a single end plate in the prior art.

[0018] 3. Through the screw with 4 pins at different positions and angles, the test applies tension to the screw, which is evenly transmitted to the concrete component through the pins, providing a stronger and evenly distributed bonding force, ensuring that the concrete specimen is subjected to uniform tension. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 It is a top view of the utility model;

[0021] Figure 3 For the utility model Figure 2 AA section view;

[0022] In the figure: 1 - U-shaped mold, 2 - inner end plate, 3 - outer end plate, 4 - pouring cavity, 5 - screw, 6 - pin, 7 - adjusting nut, 8 - washer. Detailed implementation mode

[0023] To make the above features and advantages of the present utility model more understandable, specific embodiments are hereinafter given and described in detail in conjunction with the accompanying drawings, but the present utility model is not limited thereto.

[0024] Reference Figures 1 to 3

[0025] A test mold for the tensile performance of concrete includes a U-shaped mold 1. Inner end plates 2 and outer end plates 3 are provided at both ends of the U-shaped mold. A pouring cavity 4 is formed between the inner end plates inside the U-shaped mold. Screws 5 are provided on both sides of the U-shaped mold, with one end of each screw passing through the outer end plate and the side end plate in sequence and extending into the pouring cavity. A number of pins 6 are fixed to the end of the screw located inside the pouring cavity. The other end of the screw is threadedly connected with an adjusting nut 7 located outside the outer end.

[0026] In this embodiment, the centers of the through holes or threaded holes on the inner end plates and outer end plates on both sides of the U-shaped mold for the screws to pass through are located on the same axis, ensuring the axial alignment of the test piece and avoiding the problem of uneven stress caused by eccentricity in the prior art when using a single end plate.

[0027] In this embodiment, the U-shaped mold is a wooden mold, and the inner end plate and the outer end plate are both wooden boards. The materials are convenient to obtain and the production is simple. The front and rear ends of the inner end plate and the outer end plate are connected and fixed to the U-shaped mold by nails, which is convenient for the connection between the U-shaped mold and the inner end plate and the outer end plate, and helps to remove the mold after pouring and forming.

[0028] In this embodiment, the number of the pins can be 4. The pins are fixed on the screw at intervals along the axial direction of the screw, and the axial projection of the pins on the screw is evenly arranged along the circumferential direction. The 4 pins at different positions and angles provide a more firm and evenly distributed bonding force, ensuring that the concrete test block receives uniform tensile force. In other embodiments, 5 or 6 pins can also be used.

[0029] In this embodiment, the pins are fixed radially on the screw, and the pins and the screw can be fixed by welding or threaded connection.

[0030] In this embodiment, a washer 8 sleeved on the screw is provided on the end face of the inner end plate close to the pouring cavity. The washer is a steel washer, and the washer and the screw can be connected by threading or welding, so that the screw is perpendicular to the end plate through the washer, ensuring that the screw can be fixed on the inner end plate and the outer end plate and is in the axial center position.

[0031] When in use, the method of assembling first and then pouring is adopted. First, determine the depth of the screw 5 embedded in the component, pass the screw 5 through the washer 8, the inner end plate 2 and the outer end plate 3 to ensure that the positions of the two screws 5 are aligned, assemble the assembled screw 5 with the outer end plate 3 and the inner end plate 2 to the C-shaped mold 1, adjust the position and fix it with the nut 7. After applying the release agent, pour a certain amount of concrete into the mold. After the concrete solidifies, loosen the nut 7, disassemble the C-shaped mold 1, remove the outer end plate 3, the inner end plate 2, and the washer 8, demold the poured concrete component, and after demolding, move the specimen to the standard curing room for curing to the required age for the test before starting the tensile performance test.

[0032] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the fixed connection to each other can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except where it is obviously impossible to use an one-piece molding process).

[0033] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the above utility model include states or shapes that are approximate, similar or close thereto.

[0034] Any component provided by the utility model can be assembled from multiple separate components, or can be a separate component manufactured by an integrated molding process.

[0035] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A concrete tensile performance test mold, comprising a U-shaped mold, characterized in that: The two side ends of the C-shaped mold are provided with an inner end plate and an outer end plate, and a casting cavity is formed between the inner end plates in the C-shaped mold. The two side parts of the C-shaped mold are provided with a screw rod with one end passing through the outer end plate and the inner end plate in sequence and extending into the casting cavity. A plurality of pins are fixed on the end of the screw rod located in the casting cavity, and the other end of the screw rod is threadedly connected with an adjusting nut located outside the outer end portion.

2. A concrete tensile performance test mold according to claim 1, characterized in that: The U-shaped mold is a wooden mold, and the inner end plate and the outer end plate are both wooden boards.

3. A concrete tensile performance test mold according to claim 1 or 2, characterized in that: The front and rear ends of the inner end plate and the outer end plate are connected and fixed to the U-shaped mold through nails.

4. A concrete tensile performance test mold according to claim 1, characterized in that: The pins are fixed on the screw rod at intervals along the axial direction of the screw rod, and the axial projections of the pins on the screw rod are evenly arranged along the circumferential direction.

5. A concrete tensile performance test mold according to claim 4, characterized in that: The number of the pins is more than 3.

6. A concrete tensile performance test mold according to claim 1, 2, 4 or 5, characterized in that: A washer sleeved on the screw rod is arranged on the end surface of the inner end plate close to the casting cavity, and the washer is threadedly connected or welded to the screw rod.

7. A concrete tensile performance test mold according to claim 6, characterized in that: The washers are steel washers.

8. A concrete tensile performance test mold according to claim 1, characterized in that: The centers of the through holes or threaded holes for the screws to pass through on the inner and outer end plates on both sides of the C-shaped mold are located on the same axis.

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