Test piece mold for testing bonding strength of concrete-rock interface

Abstract

The utility model relates to the technical field of concrete pouring molds, in particular to a test piece mold for testing the bonding strength of a concrete-rock interface. The mold is a cuboid without a top plate, vertical reserved seams which are perpendicular to a bottom plate and used for manufacturing initial defects are formed in the middles of two long-edge vertical plates of the mold, and the bottom plate is provided with a circular-truncated-cone-shaped air inlet hole used for pneumatic demolding. According to the utility model, the initial defect height of the interface is controlled through the sheets with different heights, the problems of interface damage and inaccurate size control caused by cutting vibration of a cutter are avoided, low-vibration and low-disturbance demolding is realized in combination with the pneumatic demolding device, and the device has the characteristics of convenience in operation, high demolding efficiency and high reliability of test data; the device is suitable for testing the bonding performance of materials such as fresh concrete and rock or old concrete.

Description

A specimen mold for testing the bond strength of concrete-rock interfaces Technical Field

[0001] This utility model relates to the field of concrete casting mold technology, specifically to a specimen mold for testing the bond strength of concrete-rock interface. Background Technology

[0002] In the performance evaluation of concrete-rock or new-old concrete composite structures, the testing of interfacial bond strength is a crucial step. Currently, commonly used testing methods mainly include the pull-out method (see GB 50086-2015 Technical Specification for Rock and Soil Anchors and Shotcrete Support Engineering) and the splitting tensile test (see GBT 50081-2019 Standard for Test Methods of Physical and Mechanical Properties of Concrete). When using the pull-out method indoors to test bond strength, the required mold size is usually large, making it inconvenient to move. Furthermore, like the field pull-out method, drilling is required for sampling, and the cutting vibration can cause some damage to the interface, resulting in test results that do not reflect the true bond performance. The mold used for the splitting tensile test is the same as that used for testing the compressive or tensile strength of cubic concrete specimens, but the test results exhibit a size effect; that is, the test results decrease as the specimen size increases, and similarly, the true bond strength of the material cannot be measured. To more reliably measure the size-effect-free bond strength of concrete-rock interface, this application proposes a mold that is easy to operate, has precise size control, and does not require cutting to avoid disturbing the specimen interface, which can be used to test the bond strength of concrete-rock interface. Summary of the Invention

[0003] To overcome the aforementioned defects, this utility model proposes a specimen mold for testing the bond strength of concrete-rock interfaces. This avoids the problems of interface damage and inaccurate dimensional control caused by cutting vibration. Combined with a pneumatic demolding device, it achieves low-vibration and low-disturbance demolding, which is convenient to operate and has high demolding efficiency, thereby ensuring the reliability of test data.

[0004] The technical solution is a specimen mold for testing the bonding strength of concrete-rock interface, characterized in that: the mold is an integral cuboid composed of a base plate (1), long side upright plates (4)(5), and short side upright plates (2)(3). The long side upright plates (4)(5) and the base plate (1) are respectively provided with reserved gaps (41)(51) and air inlets (11)(12), as well as a thin sheet (6) that is close to the surface of the base plate (1), can be inserted into the reserved gaps (41)(51), and extends to the outside of the long side upright plates (4)(5).

[0005] The above-mentioned specimen mold for testing the bond strength of concrete-rock interface is characterized in that: the mold is integrally cast from steel or plastic material.

[0006] The above-mentioned specimen mold for testing the bonding strength of concrete-rock interface is characterized in that: the mold is a topless, one-piece hollow cuboid, the thickness of its bottom plate (1) is 10mm, the thickness of its vertical plates (2)(3)(4)(5) is 5mm, and the clear size of the mold is 300×100×100mm.

[0007] The above-mentioned specimen mold for testing the bonding strength of concrete-rock interface is characterized in that: the base plate (1) is provided with two frustum-shaped air inlets (11) (12), the upper diameter d1 and the lower diameter d2 of which are 5mm and 10mm respectively, and their axes are perpendicular to the surface of the base plate (1) and are located at the center of the base plate (1) on both sides of the reserved joint (41) (51).

[0008] The above-mentioned specimen mold for testing the bonding strength of concrete-rock interface is characterized in that: a reserved gap (41)(51) with a width of 1mm and a height h1 of 60mm is provided in the middle of the long side upright plate (4)(5) of the mold.

[0009] The above-mentioned specimen mold for testing the bonding strength of concrete-rock interface is characterized in that: the thickness b2 of the thin sheet (6) is less than the width b1 of the reserved gap (41)(51), its length is 130mm, and its height h2 is greater than 0 and less than or equal to 60mm. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below.

[0011] Figure 1 is a schematic diagram of the mold structure provided by this utility model.

[0012] Figure 2 is a longitudinal side sectional view provided in this embodiment, which also shows the upper and lower hole diameters of the bottom frustum-shaped air inlet.

[0013] Figure 3 is a partial enlarged view of the reserved seam and steel sheet area in Figure 2, showing the dimensional parameters of the reserved seam and steel sheet. Detailed Implementation

[0014] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0015] As shown in Figures 1 to 3, this embodiment provides a specimen mold for testing the bonding strength of concrete-rock interface. The mold is an integral cuboid composed of a base plate (1), long side plates (4)(5), and short side plates (2)(3). The mold has reserved gaps (41)(51) and air inlets (11)(12) in the middle of the long side plates (4)(5) and the base plate (1), respectively, as well as a thin sheet (6) that is close to the surface of the base plate (1), can be inserted into the reserved gaps (41)(51), and extends to the outside of the long side plates (4)(5).

[0016] The mold is made of steel or plastic material and is cast as a whole.

[0017] The mold is a topless, one-piece hollow cuboid with a base plate (1) thickness of 10mm, vertical plates (2)(3)(4)(5) thickness of 5mm, and a clear mold size of 300×100×100mm.

[0018] The base plate (1) is provided with two frustum-shaped air inlets (11) and (12), with an upper diameter d1 and a lower diameter d2 of 5 mm and 10 mm respectively. Their axes are perpendicular to the surface of the base plate (1) and are located at the center of the base plate (1) on both sides of the reserved gaps (41) and (51).

[0019] The mold's long side upright plate (4)(5) has a reserved gap (41)(51) with a width of 1mm and a height h1 of 60mm in the middle.

[0020] The thickness b2 of the thin sheet (6) is less than the width b1 of the reserved gap (41)(51), its length is 130mm, and its height h2 is greater than 0 and less than or equal to 60mm.

Claims

1. A specimen mold for testing the bond strength of concrete-rock interface, characterized in that: The mold is an integral cuboid composed of a base plate (1), long side upright plates (4)(5), and short side upright plates (2)(3). The mold has reserved slots (41)(51) and air inlets (11)(12) in the middle of the long side upright plates (4)(5) and the base plate (1), respectively, as well as a thin sheet (6) that is close to the surface of the base plate (1), can be inserted into the reserved slots (41)(51), and extends to the outside of the long side upright plates (4)(5).

2. The specimen mold for testing the bond strength of concrete-rock interface according to claim 1, characterized in that: The mold is made of steel or plastic material and is cast as a whole.

3. The specimen mold for testing the bond strength of concrete-rock interface according to claim 1, characterized in that: The mold is a one-piece hollow cuboid without a top plate. Its bottom plate (1) is 10mm thick, and the vertical plates (2)(3)(4)(5) are 5mm thick. The clear dimensions of the mold are 300×100×100mm.

4. The specimen mold for testing the bond strength of concrete-rock interface according to claim 1, characterized in that: The base plate (1) is provided with two frustum-shaped air inlets (11) and (12), with an upper diameter d1 and a lower diameter d2 of 5 mm and 10 mm respectively. Their axes are perpendicular to the surface of the base plate (1) and are located at the center of the base plate (1) on both sides of the reserved gaps (41) and (51).

5. The specimen mold for testing the bond strength of concrete-rock interface according to claim 1, characterized in that: The mold's long side upright plate (4)(5) has a reserved gap (41)(51) with a width of 1mm and a height h1 of 60mm in the middle.

6. The specimen mold for testing the bond strength of concrete-rock interface according to claim 1, characterized in that: The thickness b2 of the thin sheet (6) is less than the width b1 of the reserved gap (41)(51), its length is 130mm, and its height h2 is greater than 0 and less than or equal to 60mm.

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