JPH06331521A - Method and apparatus for measuring tensile strength of fragile solid material and the like - Google Patents

Abstract

PURPOSE:To preferably and easily mount a test piece to be sampled of a fragile solid material, etc., like a concrete semicured molded from, a soil block, etc., on a tensile tester and to effectively conduct its tensile test. CONSTITUTION:In order to measure the tensile strength of a fragile solid material, etc., to be tested by mounting and supporting both end faces 2a, 2b of a test piece 1 to be sampled of the material to corresponding mounting units 12, 13 of a tensile tester 11 and applying a tensile load between the units 12 and 13, vacuum evacuating means 21a, 21b having a plurality of suction holes 25a, 25b opened at the means 21a, 21b or suction surfaces 24a, 24b are respectively disposed at the units 12 and 13. The faces 2a, 2b of the test piece 1 are attracted and supported by the suction between the means 21a and 21b or between the faces 24a and 24b of the means 21a, 21b while the faces 2a, 2b are in contact with the faces 24a and 24b, and then the tensile strength is measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring tensile strength of fragile solids and the like and a measuring apparatus therefor. More specifically, for example, a semi-hardened concrete molded product, an aluminum powder-containing aerated concrete molded product, etc. The present invention relates to a measuring method and a measuring device for measuring the tensile strength of a sample test body such as a solid that is relatively fragile such as a soil block body extracted in a block shape.

[0002]

2. Description of the Related Art Generally, if it is possible to measure the tensile strength of this type of concrete, each semi-hardened compact such as aerated concrete containing aluminum powder, and the fragile solid such as soil block, for example, it is manufactured in a factory. It is possible to know the tensile strength value for estimating cracks that occur when handling various concrete products, especially products that are in a semi-hardened state, and similar cracks that occur in soil,
Its industrial utility value is great.

[0003]

Here, for example, the tensile strength test of concrete products has already been specified as JIS A 1113 (1976) in Japanese Industrial Standards, but this is the curing for a predetermined period. It is applied to the final product of concrete that has been sufficiently hardened and the strength itself has been improved. As in this case, various types of semi-hardened concrete that have not yet been strengthened in the semi-hardened state It is not applicable to the body, and this is also the case in soils that are inherently poorly tacky and fragile.

As described above, different from powders in particular, it is necessary to measure the tensile strength of various concrete semi-hardened compacts having a certain degree of bonding structure and brittle solids such as soil blocks. In the past, it was impossible to carry out the test because there was no effective and appropriate means for attaching and mounting the sample test body to the tensile tester.

Therefore, the object of the present invention is to provide various semi-hardened concrete compacts and sample specimens such as fragile solids such as soil blocks, which can be easily and easily mounted on a tensile tester. It is an object of the present invention to provide a method for measuring tensile strength of a brittle solid or the like of this kind and a measuring apparatus for the same, which enables the tensile test to be effectively performed.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the inventors of the present invention relate to various concrete semi-hardened compacts and sample test bodies such as fragile solids such as soil blocks, As a result of continuous research efforts on means for effectively mounting and supporting this on a tensile tester, the present invention has been completed. Are vacuum-adsorbed and supported.

That is, according to the present invention, both end faces of a sample test body such as a fragile solid are attached to and supported by the corresponding attachment / attachment portions of the tensile tester, and tension is applied between the attachment / attachment portions. A method for measuring the tensile strength of a fragile solid or the like by applying a load, wherein vacuum attachment means is arranged at each of the mounting and mounting parts, and both ends of the sample test body are placed between these vacuum attachment means. A fragile solid or the like characterized in that the tensile strength is measured after the respective abutting surfaces are adsorbed and supported by the vacuum suction force applied to the respective vacuum adsorbing means in a state in which the respective surfaces are abutted against each other. Is a method for measuring tensile strength.

Further, according to the present invention, both end faces of a sample test body such as a fragile solid are attached to and supported by the corresponding attachment / attachment portions of the tensile tester, and tension is applied between the attachment / attachment portions. A tensile strength measuring device for a fragile solid or the like, which is performed by applying a load, wherein each of the mounting / attaching parts is formed by arranging a vacuum suction means having a plurality of suction holes opened on a suction surface. While holding both end faces of the sample test body between the suction surfaces of the respective vacuum suction means, the contact portions are sucked through the respective suction holes by the vacuum suction force applied to the respective vacuum suction means. A tensile strength measuring device for a fragile solid or the like characterized by being supported.

[0009]

Therefore, according to the method of the present invention, since the vacuum suction means is arranged for each attachment and mounting portion in the tensile tester, both ends of the sample test body are interposed between these vacuum suction means. With the surfaces in contact with each other, the vacuum suction force applied to each of the vacuum suction means can vacuum-suck a sample test body such as a fragile solid, and can reliably support it to measure the tensile strength. It will be possible.

Also, in the apparatus of the present invention, since the vacuum suction means having a plurality of suction holes on the suction surface are arranged for the respective mounting parts, the vacuum suction means of each of these vacuum suction means is arranged. With both end surfaces of the sample test body in contact with each other between the suction surfaces, the vacuum suction force applied to each of the vacuum suction means can vacuum-suck a sample test body such as a fragile solid through each suction hole. However, similarly, this can be reliably supported and the tensile strength can be measured.

[0011]

EXAMPLES Examples of the method for measuring the tensile strength of fragile solids and the like according to the present invention and the measuring apparatus therefor will be described below with reference to FIGS.
Will be described in detail with reference to.

FIG. 1 is a structural explanatory view showing an outline of a tensile strength measuring apparatus to which an embodiment of the present invention is applied in a mounted and supported state of a sample test body, and FIG. It is a graph which shows the strain-stress relationship by an example of the result of carrying out the tensile test of the sample test body using it.

In the apparatus of the embodiment shown in FIG. 1, 1
Is a fragile solid sample test body composed of various concrete semi-hardened compacts, soil block bodies, and the like, which are the objects of measurement here. Reference numeral 11 represents a tensile tester having a known structure used for measuring the tensile strength of the sample test body 1. The tensile tester 11 has a fixing portion 12 (one of the mounting / mounting portions on one side) at a lower position as a portion corresponding to a tensile operation. , And movable parts 13 (corresponding to the other mounting and mounting parts) are respectively set in the upper position, and the movable parts 13 are connected via a load cell 14 to a hydraulic drive part (not shown) and fixed. A relative pulling action for measurement is performed with the part 12. Further, 21a and 21b are upper and lower parts for attaching and supporting the sample test body 1 to a fixed part 12 on the lower side and a movable part 13 on the upper side, which are set at respective upper and lower positions of the tensile tester 11. Each vacuum suction device is composed of one set.

Thus, the fragile solid sample test body 1
In the case of the apparatus of this embodiment, it is desirable that the external shape is a cylindrical shape, or a cylindrical shape in which the peripheral side surface of the central portion in the longitudinal axis direction is narrowed down to some extent, and its size is not necessarily limited. Although not limited to this, for example, when various concrete semi-hardened compacts are used as the sample test body 1 here, the diameter is about 100 mm, and the vertical length (height) is about 200 mm. It is preferable that the upper and lower end surfaces 2a and 2b are parallel to each other at right angles to the longitudinal direction, and the flatness of the end surface, and thus the allowable range of unevenness on the end surface, does not exceed about 1 mm. To form. When the sample test body 1 is various concrete semi-hardened molded bodies, it may be molded by mold casting using a required mold or other suitable means, while the soil block body In this case, the target soil mass can be easily molded by cutting it out into a similar shape and dimension with a commercially available trimmer or the like.

Subsequently, the vacuum suction devices 21a and 21b consisting of a pair of the upper and lower parts are fixedly mounted on the lower fixed part 12 and the upper movable part 13 of the tensile tester 11, respectively, Any structure may be adopted as long as both end surfaces of the sample test body 1 can be reliably sucked and supported as expected, but in the case of the apparatus of this embodiment, each of these vacuum suction devices 21 is used.
a and 21b have box-shaped adsorber bodies 22a and 22b having vacuum decompression chambers 23a and 23b formed therein, and one of the adsorption end faces of the adsorber bodies 22a and 22b that are parallel to each other The end faces 24a, 24b have a plurality of suction holes 25a, 25 communicating with the vacuum decompression chambers 23a, 23b.
b are opened in a relatively dense state, and mounting jigs 27a and 27b for mounting the corresponding fixed portion 12 and movable portion 13 are fixed to the other mounting end surfaces 26a and 26b, respectively. And each of the vacuum decompression chambers 23a,
A vacuum decompression source such as a suction pump (not shown) is connected to 23b through a three-way switching valve 31 provided with a leak valve 32. Here, the formation range of the adsorption holes 25a, 25b opened in the adsorption end faces 24a, 24b of the adsorber bodies 22a, 22b may be within the range of the adsorbed end faces of the sample test body 1. The diameter of each of the suction holes 25a and 25b is in the range of 1 mm to 30 mm, preferably 2 mm to 10 mm in order to prevent clogging and the like, and the aperture ratio is about 10% to 80%. 40% to 60
It is preferably within the range of%. The vacuum decompression degree of each of the vacuum decompression chambers 23a and 23b depends on the fragility of the sample test body 1 to be measured, but normally, several tens Torr is sufficient. The adjustment of the degree of vacuum pressure reduction by the vacuum pressure reduction source such as is performed by the leak valve 32.

Therefore, in order to conduct a tensile test by the apparatus of this embodiment, the vacuum suction device 21a corresponding to the lower fixed portion 12 of the tensile tester 11 and the corresponding vacuum suction portion of the upper movable portion 13 of the tensile tester 11 are used. In a state in which the suction devices 21b are fixed to each other and the three-way switching valve 31 is opened to evacuate each of the vacuum decompression chambers 23a and 23b, first, the vacuum suction device 21a corresponding to the lower side is used. The sample test body, in this case, the sample test body 1 made of a fragile solid is placed so that its lower end surface 2a is in contact, and the load cell 14 is loaded with zero load so as to cover the opening range of each suction hole 25a. Then, the opening range corresponding portion of each suction hole 25b in the vacuum suction device 21b corresponding to the upper side is lightly pressed and set on the upper end surface 2b of the mounted sample test body 1 this time. . When the sample test body 1 is set in this way, the vacuum decompression chambers 23a, 23a
b, the respective suction holes 25a, 25b are closed by the corresponding end faces 2a, 2b, and the load cell 1
4, the pressing force of each vacuum suction device 21a, 21b with respect to the sample test body 1, that is, the compression load is shown. Then, in this state, the inside of each vacuum decompression chamber 23a, 23b is evacuated by the vacuum decompression source, and the load valve 14 is adjusted to zero load by adjusting the leak valve 32. In other words, by this series of operations, both end surfaces 2 of the sample test body 1
a and 2b are adsorbed to the respective vacuum adsorbers 21a and 21b by vacuum decompression through the corresponding adsorption holes 25a and 25b, and as a result, the tensile test of the sample test body 1 against the tensile tester 11 is performed. Therefore, the tensile test may be carried out in exactly the same manner as in the usual case. In this way, the sample test body 1 using a fragile solid, which has been practically impossible in the past, can be obtained. Regarding this tensile test, in this embodiment, the sample test body 1 can be adsorbed and supported in a balanced manner in a tensile direction, and the tensile test can be easily performed.

In addition, in the tensile test, the suction force for supporting the sample test body 1 is the same as the sample test body 1
It corresponds to the compressive load when each of the vacuum adsorbers 21a and 21b is pressed against, and the compressive load may be selected according to the state of the sample test body 1, but in the normal case,
The supporting / adsorbing force for the sample test body 1 is preferably within a range of about 5% to 40% of the compressive strength of the sample test body 1. Furthermore, in this case, since the sample test body 1 to be handled is a solid that is weak in strength,
For example, when a part of the end face as the attracted face is missing or a vacuum leak occurs, it is effective to seal the corresponding part with an adhesive such as clay.

Next, a specific example of the tensile test in the present invention will be described. Here, as the sample test body in this example, a semi-hardened molded concrete of aerated concrete containing aluminum powder is used.

First, in this case, the aerated concrete compact containing aluminum powder uses silica stone, cement, lime, gypsum, concrete recovery waste, and water as its raw materials, and each of these components is placed in a constant temperature water tank in a mixer. After being mixed with stirring in sequence, the aluminum powder, which is a foaming agent, is further added and mixed, and the slurry thus obtained is poured into a mold prepared in advance for molding.
Here, as the mold for molding, JIS A described above is used.
Approximately 10 cylinders with a diameter of 100 mm and a height of 200 mm in the concrete strength test specimen of 1113 (1976) were used.
It suffices to use a product that is raised by about 0 mm with a Teflon sheet. Then, the molded body to be injection-molded, in this case, the sample test body, is raised at a constant temperature rising rate to a temperature of 45 ° C. to 70 ° C. in a constant temperature and constant humidity chamber for each of the molds, and then a humidity of 80 % R. H. Under constant conditions, and in this state, it is allowed to stand for 3 hours, that is, pre-curing is performed. Next, the aerated concrete semi-hardened compact containing aluminum powder that has been left standing in the constant temperature and humidity chamber is taken out from the mold, and each end face is cut out so that both end faces are flat and parallel. In addition, a notch is made in a part of the corresponding central portion so that the final breakage in the tensile test can be made from the central portion. That is, in this way, a sample test body composed of the required aerated concrete semi-hardened compact containing aluminum powder is obtained.
It was a cylinder with a length of 00 mm and a length (height) of 200 mm, and the load at the time of compression fracture was within the range of 55 Kg to 156 Kg.

On the other hand, as described above, each vacuum suction device is fixed to the lower fixed portion and the upper movable portion of the tensile tester. In this case, each suction hole in each vacuum suction device has a hole diameter of 3 mmφ and an opening ratio of 45%.

Then, after placing the sample test body so as to cover each suction hole of the lower side vacuum suction device with the lower end surface, a portion corresponding to each suction hole of the upper side vacuum suction device is placed on the upper end surface of the sample test body. By pressing lightly, approximately 3K can be applied to the sample test piece.
A compressive load of about gf is applied. In addition, since the sample test body applied here is a kind of porous body, it is necessary to prevent vacuum leakage from the vicinity of the end face portion which is supposed in advance. Is circumferentially sealed with clay.

Then, in this state, with the three-way switching valve and the leak valve open, the vacuum suction pump is driven to evacuate each vacuum decompression chamber, and the leak valve is slowly closed. As the vacuum decompression degree in each vacuum decompression chamber increases, the sample test body is gradually sucked, the load cell shows zero load at about 40 Torr, and the adsorption support of the sample test body is secured in this state. Period tensile test is now possible. Then, as a result of performing a tensile test as usual, the strain-stress relationship curve in the sample test body is as shown in FIG.
It was confirmed that it showed a curve that was approximately similar to the case of a general tensile test. That is, from the strain-stress curve of FIG. 2, the tensile strength of the aerated concrete semi-cured molded body containing aluminum powder that has been left standing (pre-cured) in the constant temperature and humidity chamber in this case for 3 hours is shown. But 0.07 Kgf /
It could be measured to be about cm ² .

In the above-mentioned examples and specific examples, the case where the object of measuring the tensile strength is a solid having relatively weakness such as various concrete semi-hardened compacts and soil blocks is described. It is needless to say that the present invention can be applied not only to such brittle solids but also to a tensile test of any object.

[0024]

As described above in detail with reference to the embodiments,
According to the present invention, both end surfaces of a sample test body such as a fragile solid are attached to and supported by the respective attachment mounting portions of the tensile tester, and a tensile load is applied between the respective attachment mounting portions. In measuring the tensile strength of fragile solids, etc., the vacuum suction means or the vacuum suction means having a plurality of suction holes opened on the suction surface is arranged for each mounting portion, and each of these vacuums is attached. Between the suction means, between the suction means, between the suction surfaces of the respective vacuum suction means, with both end surfaces of the sample test body in contact with each other, by the vacuum suction force applied to each vacuum suction means, each contact Since the tensile strength is measured after the surface is adsorbed and supported, in the conventional case, it is difficult to mount and support each mounting and mounting part due to its weakness, and it is impossible to measure the tensile strength. For fragile solid samples However, it can be easily adsorbed and reliably supported, and in this way it is possible to measure the tensile strength as expected, and as a result, the tensile strength of fragile solids etc. can be easily evaluated. And the substantial effect is extremely large.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view schematically showing an outline of a tensile strength measuring device to which an embodiment of the present invention is applied in a mounted and supported state of a sample test body.

FIG. 2 is a graph showing a strain-stress relationship according to an example of a result of a tensile test of a sample test body using the apparatus of the same Example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fragile solid sample test body 2a, 2b Adsorbed end surface of sample test body 11 Tensile tester 12 Lower fixed part (one mounting / mounting part) 13 Upper movable part (other mounting / mounting part) 14 Load cell 21a , 21b Vacuum adsorber 22a, 22b Adsorber body 23a, 23b Vacuum decompression chamber 24a, 24b Adsorption end face 25a, 25b Adsorption hole 26a, 26b Mounting end face 27a, 27b Mounting jig 31 Three-way switching valve 32 Leak valve

Claims (2)

[Claims] 1. The respective mounting and mounting parts of the tensile tester are mounted and supported on both end faces of a sample test body such as a fragile solid, and a tensile load is applied between the respective mounting and mounting parts. A method for measuring the tensile strength of a fragile solid or the like performed by disposing vacuum suction means in each of the mounting and mounting parts,
In addition, between the respective vacuum suction means, the respective contact surfaces are suction-supported by the vacuum suction force applied to the respective vacuum suction means in a state where both end surfaces of the sample test body are in contact with each other. A method for measuring the tensile strength of a brittle solid or the like, which comprises measuring the tensile strength after the treatment. 2. The tensile tester is attached to and supported by the corresponding mounting / attaching portions, and both end faces of a sample test body such as a fragile solid are mounted and supported, and a tensile load is applied between the mounting / attaching portions. A tensile strength measuring device for a fragile solid or the like, which is configured by arranging a vacuum suction means having a plurality of suction holes opened on a suction surface in each of the mounting / attaching parts. While the both end surfaces of the sample test body are in contact with each other between the suction surfaces of the respective contact portions, each contact portion is suction-supported through each suction hole by the vacuum suction force applied to each vacuum suction means. A tensile strength measuring device for fragile solids, etc.