Die for thin-wall circular tube test piece made of cement mortar materials

Abstract

The utility model discloses a mold for a thin-wall circular tube test piece made of cement mortar materials. The mold consists of a bottom plate, an outer ring standing plate and an inner ring standing plate, the upper surface of the bottom plate is provided with two circular grooves which are respectively matched with the outer ring standing plate and the inner ring standing plate, and a gap is reserved between the outer ring standing plate and the inner ring standing plate to pour a test piece; each of the outer ring standing plate and the inner ring standing plate is cut into three equal parts along the circumferential direction, the inner ring standing plate is cut into three equal parts along the circumferential direction to form an inverted V-shaped notch, and lubricating oil is added on the plate surface between the outer ring standing plate and the inner ring standing plate and a plastic film is applied on the plate surface between the outer ring standing plate and the inner ring standing plate. According to the utility model, a space between the inner and outer ring standing plates is used as a forming space of a test piece; the inner ring standing plate and the outer ring standing plate are mounted on the bottom plate simply and conveniently; plastic films are attached to the inner and outer surfaces of the test piece to facilitate demolding; the notch of the inner standing plate is inverted-V-shaped so that the inner ring standing plate can be withdrawn inwards conveniently.

Description

Technical Field

[0001] The utility model belongs to the technical field of material mechanical property experimental equipment, in particular to a mold for a thin-walled round tube test piece of cement mortar material. Background Art

[0002] Cement mortar is one of the most widely used engineering materials. It is an important component of concrete. The study of its mechanical properties is very important. On the one hand, it will be directly used in engineering, and on the other hand, the study of its performance is the basis for the study of the mechanical properties of concrete. Compared with tensile and compressive properties, shear resistance is more important and more difficult to study. General shear tests cannot obtain the mechanical properties of materials in a pure shear state. The best test to obtain the mechanical properties of materials in a pure shear state is to perform a torsion test on thin-walled circular tube specimens. To ensure an approximate pure shear state, the shear stress is required to be approximately equal along the radial direction (wall thickness direction). Because the shear stress is distributed linearly along the radial direction during torsion, the wall thickness must be relatively thin. It is generally believed that a thin-walled circular tube with a wall thickness of 1 / 20 of the diameter can be considered, and its stress state when torsion is considered to be a pure shear stress state.

[0003] Due to the limitation of the size of the testing machine, the size of the torsion test piece cannot be made too large. A diameter of 100mm is already a relatively large torsion test piece. Even a thin-walled round tube with a diameter of 100mm has a wall thickness of only 5mm. The strength of cement mortar is relatively low. The success rate of forming and demoulding such a thin test piece is very low. Utility Model Content

[0004] The utility model aims to provide a mold for thin-walled round tube test pieces of cement mortar materials, so as to make up for the shortcomings of existing forming demoulding technology.

[0005] In order to achieve the above-mentioned utility model purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a mold for thin-walled round tube test pieces of cement mortar materials, the mold consisting of a bottom plate, an outer ring stand plate and an inner ring stand plate;

[0007] The upper surface of the bottom plate has two circular grooves which match the outer ring plate and the inner ring plate respectively, and a gap is left between the outer ring plate and the inner ring plate to cast the test piece;

[0008] The outer ring station plate and the inner ring station plate are both hollow cylinders, and their heights are the sum of the specimen height and the circular groove depth. The inner circle diameter of the outer ring station plate is equal to the outer diameter of the specimen, and the outer circle diameter of the inner ring station plate is equal to the inner diameter of the specimen. The outer ring station plate and the inner ring station plate are both cut into three equal parts along the circumferential direction.

[0009] Further technology of the utility model:

[0010] Preferably, the bottom plate has open through holes for fixing with a heavy-mass steel plate.

[0011] Preferably, threaded holes are provided on the bottom end surfaces of the outer ring station plate and the inner ring station plate, and a plurality of step holes are processed on the back side of the circular groove, and the step holes are used to fix the outer ring station plate and the inner ring station plate with bolts.

[0012] Preferably, the bottom end surfaces of the outer ring station plate and the inner ring station plate are provided with pin holes, and the outer ring station plate, the inner ring station plate and the bottom plate are positioned by pins.

[0013] Preferably, the inner ring station plate is cut into three equal parts along the circumferential direction in an inverted V-shape, with the V opening toward the inner circle.

[0014] Preferably, the width of the V-mouth is not less than (2π / 3)x(R-r), wherein R and r are respectively the outer radius and the inner radius of the inner ring station plate.

[0015] Preferably, lubricating oil is applied to the plate surface between the outer ring station plate and the inner ring station plate and a plastic film is applied.

[0016] Compared with the prior art, the utility model has the following technical effects:

[0017] In the utility model, the space between the inner and outer ring plates is used as the forming space of the specimen; the inner and outer ring plates are installed on the bottom plate, which is simple and convenient; the plastic film is attached to the inner and outer surfaces of the specimen for easy demoulding; the cutout of the inner plate is in an inverted V shape for easy withdrawal of the inner ring plate. The bottom plate is fixedly connected to the large mass plate through a through hole to facilitate vibration during the forming process. The utility model mold facilitates the forming of thin-walled low-strength specimens and greatly improves the forming success rate.

[0018] Other features and advantages of the present invention will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a front view of the mold of the present utility model.

[0021] Figure 2 This is a schematic diagram of the mold bottom plate of the utility model;

[0022] Figure 3 It is a bottom view of the combined structure of the outer ring station plate and the inner ring station plate of the utility model;

[0023] Explanation of numbers in the figure: 1-base plate, 2-outer ring station plate, 3-inner ring station plate, 4-circular groove, 5-test piece, 6-open through hole, 7-threaded hole, 8-step hole, 9-bolt, 10-V-shaped, 11-pin hole, 12-pin, 13-mass steel plate. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be further described in detail below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model but not all. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0025] like Figure 1-3 , this embodiment provides a mold for a cement mortar material thin-walled circular tube specimen 5, the mold consisting of a bottom plate 1, an outer ring station plate 2 and an inner ring station plate 3;

[0026] The upper surface of the bottom plate 1 has two circular grooves 4 which respectively match the outer ring station plate 2 and the inner ring station plate 3, and a gap is left between the outer ring station plate 2 and the inner ring station plate 3 to cast the test piece 5;

[0027] The outer ring station plate 2 and the inner ring station plate 3 are both hollow cylinders, and their heights are the sum of the height of the specimen 5 and the depth of the circular groove 4. The inner diameter of the outer ring station plate 2 is equal to the outer diameter of the specimen 5, and the outer diameter of the inner ring station plate 3 is equal to the inner diameter of the specimen 5. The outer ring station plate 2 and the inner ring station plate 3 are both cut into three equal parts along the circumferential direction.

[0028] The bottom plate 1 has an open through hole 6 and is fixed with a heavy-mass steel plate 13 to facilitate its vibration during the forming process.

[0029] The bottom end surfaces of the outer ring station plate 2 and the inner ring station plate 3 are provided with threaded holes 7, and the back side of the circular groove 4 is processed with a plurality of stepped holes 8, and the stepped holes 8 are used to fix the outer ring station plate 2 and the inner ring station plate 3 with bolts 9.

[0030] The bottom of the circular groove 4 is provided with a pin hole 11, and the bottom end surfaces of the outer ring station plate 2 and the inner ring station plate 3 are provided with pins 12, and the pins 12 are inserted into the pin holes 11 to position the outer ring station plate 2 and the inner ring station plate 3.

[0031] The inner ring station plate 3 is cut into three equal parts along the circumferential direction in an inverted V shape, with the V opening inwardly. The width of the V opening is not less than (2π / 3)x(R-r), where R and r are the outer circle radius and the inner circle radius of the inner ring station plate 3 respectively.

[0032] Lubricating oil is applied to the plate surface between the outer ring station plate 2 and the inner ring station plate 3 and a plastic film is applied.

[0033] First, use bolts 9 to fix the outer ring station plate 2 and the inner ring station plate 3 on the bottom plate 1 respectively, and add a little lubricating oil. Apply plastic film. Connect the assembly to the large mass block through the through hole of the bottom plate 1, and place it on the vibration table after connection. Then add the mixed cement mortar, and after filling it up, start the vibration table to vibrate according to the specifications, and continue to add slurry during the vibration process. After the vibration is completed, scrape the upper mouth flat, let it stand for 24 hours, and then start demoulding. When demoulding, first remove the bolts 9 that fix the outer ring station plate 2 and the inner ring station plate 3, then gently open the outer ring station plate 2 outwards, and gently open the inner ring station plate 3 inwards. After successful demoulding, remove the test piece 5 and take it to the curing room for standardized curing until it is usable.

[0034] Preferably, the base plate 1 can be appropriately enlarged, and one base plate 1 can be used to place multiple sets of inner and outer ring station plates 2 to increase work efficiency.

[0035] The above contents are merely examples and explanations of the structure of the utility model. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of the utility model.

Claims

1. A mold for a thin-walled round tube specimen of cement mortar material, characterized in that: The mold consists of a base plate, an outer ring station plate and an inner ring station plate; The upper surface of the bottom plate has two circular grooves which match the outer ring plate and the inner ring plate respectively, and a gap is left between the outer ring plate and the inner ring plate to cast the test piece; The outer ring station plate and the inner ring station plate are both hollow cylinders, and their heights are the sum of the specimen height and the circular groove depth. The inner circle diameter of the outer ring station plate is equal to the outer diameter of the specimen, and the outer circle diameter of the inner ring station plate is equal to the inner diameter of the specimen. The outer ring station plate and the inner ring station plate are both cut into three equal parts along the circumferential direction.

2. A mold for cement mortar material thin-walled round tube specimens according to claim 1, characterized in that: The bottom plate is provided with open through holes for fixing with a heavy-mass steel plate.

3. A mold for cement mortar thin-walled round tube specimens according to claim 1, characterized in that: The bottom end surfaces of the outer ring station plate and the inner ring station plate are provided with threaded holes, and the back side of the circular groove is processed with a plurality of step holes, which are used to fix the outer ring station plate and the inner ring station plate with bolts.

4. A mold for cement mortar thin-walled round tube specimens according to claim 1, characterized in that: The bottom of the circular groove is provided with a pin hole, and the bottom end surfaces of the outer ring station plate and the inner ring station plate are provided with pin holes, and the outer ring station plate, the inner ring station plate and the bottom plate are positioned by pins.

5. A mold for cement mortar material thin-walled round tube specimens according to claim 1, characterized in that: The inner ring station plate is cut into three equal parts along the circumferential direction and is in an inverted V shape, with the V opening toward the inner circle.

6. A mold for cement mortar material thin-walled round tube specimens according to claim 5, characterized in that: The width of the V-mouth is not less than (2π / 3)x(R-r), where R and r are the outer radius and inner radius of the inner ring station plate respectively.

7. A mold for cement mortar material thin-walled round tube specimens according to claim 1, characterized in that: Lubricating oil is applied to the plate surface between the outer ring station plate and the inner ring station plate and a plastic film is applied.

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