JP2003270111A - Variable type test anvil for non-destructive strength testing-machine for concrete or the like, testing method for non-destructive strength testing-machine, and testing method for non-destructive strength for concrete or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure hardness of a structure surface in concrete or the like. <P>SOLUTION: In this variable type test anvil 300 for a non-destructive strength testing machine for the concrete or the like, a striking piece part 362 is installed in one side face of an anvil main body 310, the piece part 362 is held at proper pressure from an inside of the anvil main body 310 by a pressure imparting mechanism such as oil pressure, and a degree of repulsion in the striking piece part 362 is made variable thereby to be set to a surface repulsion degree of the concrete structure of a prescribed compression strength. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable test anvil for a nondestructive strength tester for measuring the degree of repulsion of the surface of a structure such as concrete, and a test method for the nondestructive strength tester using the variable test anvil. And a non-destructive strength test method for concrete and the like.

[0002]

2. Description of the Related Art In structures such as concrete,
By measuring the surface repulsion degree, it is possible to estimate whether or not a predetermined compressive strength is obtained. For this reason,
Conventionally, a non-destructive strength tester called a concrete test hammer has been used.

The general principle and usage of this nondestructive strength tester are as follows. First, this tester roughly has, for example, an ippact spring and a hammer mass (weight) associated with the ippact spring in a portable tubular housing, and when used, protrudes from the tip of the housing. The plunger (striking culm) is pressed against the surface of the concrete structure. Then, since the plunger is pushed back into the housing, the ippact spring is extended inside and the hammer mass is also retracted to a predetermined position. Then, when the hammer mass reaches a predetermined position (operating position), the locking means is released, so that the hammer mass violently rushes (forwards) by the restoring force (accumulation pressure) of the ippact spring to move the plunger. Hit and hit the surface of the concrete structure. At the time of this impact, the hammer mass is momentarily pushed back according to the degree of surface resilience of the concrete structure. The compressive strength of concrete can be estimated by measuring the amount of return (rebound).

[0004]

However, in the case of a non-destructive strength tester having such a structure, when it is used many times or stored without being used for a long period of time, the empirically correct restitution degree is There was a tendency not to get. Therefore, in general, when using the test anvil (verifier) 20 with the nondestructive strength tester 100, as shown in FIG.
A hitting test was performed a predetermined number of times on 0, and an average value thereof was obtained to confirm whether or not a predetermined stable rebound degree was obtained.

Usually, as the test anvil 200, from the viewpoint of durability and reproducibility, a test piece made of a metal block having a high hardness in the non-hit portion and having a constant mass is used. In the case of a metal lump, its resilience is high, and a value of about 80 is obtained when a hitting test is performed with a normal nondestructive strength tester 100. This resilience is a considerably high value around 30 (a value that is empirically confirmed) which is a value when it is assumed that a general concrete structure is solidified at a predetermined compressive strength.

However, at present, there is no test anvil made of a material just corresponding to the surface repulsion degree of the concrete structure, so the impact test with the test anvil 200 made of metal lumps gives a value of 80 ± 2 (reference value). ) Is obtained, the non-destructive strength tester 100 is defined as a passing product.

That is, in the case of the non-destructive strength tester 100 which has obtained the reference value of 80 ± 2, the rebound degree is 30.
It is based on the inference that an appropriate degree of repulsion will be measured even in the impact test on a concrete structure having a value far from the front and back.

As described above, the reason why the reasoning must be based on such inference is that it has a resilience of about 30 which is close to the surface resilience of a concrete structure, and has sufficient durability and reproducibility. It was because it was difficult to find a suitable material for the test anvil, which was equipped with such things.

Further, according to the research conducted by the present inventors, it has been found that the following problems occur when the test anvil 200 made of a metal ingot is used. That is, as will be apparent from the test data described later, by using some (a plurality of) of non-destructive strength testers 100 of acceptable products, the standard value of 80 ± 2 was obtained by the test anvil 200 made of metal lumps. It was found that even when the impact test was conducted on the same concrete structure, a considerable variation occurred.

This means that if it is within the conventional reference value of 80 ± 2, there is a suspicion in terms of reliability in the case of the judgment method of the nondestructive strength tester which is an acceptable product. In addition,
In the impact test on a concrete structure, due to the characteristics of the concrete surface (such as the impact surface being considerably deformed by one impact), the impact surface is slightly shifted, and multiple locations (usually about 20 locations each 3 cm vertically or horizontally) (Shifted) is hit and the repulsion degree of the average value is calculated. For this reason, in the strict sense, it is not a hit at the same point for each aircraft, so naturally variations due to this are also expected, but the actual magnitude of the variations is, even if this point is taken into consideration. The size was unexplainable.

The present invention has been made from such a point of view. First, one of them is that the rebound can be appropriately set to about 30 which is close to the surface rebound of a general concrete structure. While providing a variable test anvil that has never existed before, the other is a more reliable test of the non-destructive strength tester itself by using a conventional metal ingot test anvil together with this variable test anvil. It is intended to provide a method and a nondestructive strength test method for concrete and the like.

[0012]

According to the present invention, a striking piece portion is installed on one side surface of an anvil body, and the striking piece portion is pressed and held from the inside of the anvil body by an appropriate pressure. It is a variable test anvil for non-destructive strength testing machines such as concrete.

The present invention according to claim 2 is characterized in that the hitting piece portion is pressed and held by a pressure applying mechanism such as hydraulic pressure, and the variable type test for a non-destructive strength tester for concrete or the like according to claim 1 is characterized. Located in the anvil.

According to a third aspect of the present invention, the striking piece portion is attached to a plunger rod of a cylinder incorporated in the anvil body, and pressurized oil is supplied from the outside into the cylinder to strike the striking piece portion. The variable test anvil for a nondestructive strength tester for concrete or the like according to claim 1, characterized in that

The present invention according to claim 4 is characterized in that the pressing force to the hitting piece portion is adjusted so that the resilience thereof is substantially equal to the resilience of an object such as concrete. A variable test anvil for a non-destructive strength tester such as concrete described in 2 or 3.

According to a fifth aspect of the present invention, the striking piece portion can be replaced.
It is a variable test anvil for a non-destructive strength tester such as concrete described in 2, 3, or 4.

According to the sixth aspect of the present invention, in testing a nondestructive strength tester for concrete or the like, a hitting test is performed on a test anvil made of a metal ingot by the nondestructive strength tester, and the resilience is measured. On the other hand, the impact test was performed on the variable test anvil in which the impact piece part installed on one side of the anvil body was adjusted in terms of its rebound by pressing and holding from within the anvil body to be almost equal to the object such as concrete. The non-destructive strength tester is a passing machine if the two repulsion degrees are within a predetermined acceptable range.

According to the invention of claim 7, in measuring the surface resilience of an object such as concrete, a non-destructive strength tester is used to perform a striking test on a test anvil made of a metal block, and the resilience thereof is measured. On the other hand, the impact piece part installed on one side of the anvil body strikes against a variable test anvil whose rebound is adjusted to be almost the same as an object such as concrete by holding pressure from within the anvil body. Perform a test and determine the resilience, and if both these resiliences are within the prescribed passing range, hit the object such as concrete with the non-destructive strength tester to obtain the resilience. This is a nondestructive strength test method for concrete and the like.

[0019]

1 and 2 show an embodiment of a variable test anvil for a nondestructive strength tester for concrete or the like according to the present invention. In this variable test anvil 300, 310 is the anvil body.
This is not particularly limited, but is formed from a metal block such as iron or aluminum block.

In the vertical direction of the anvil body 310 in the figure,
A circular cylinder hole 311 is formed, and a cylinder chamber R is formed inside. The lower end of the cylinder chamber R in the figure is closed by a cap-shaped lower lid member 321. This lower lid member 3
A disc-shaped ring seat 330 is fitted on the outer periphery of the ring 21. The lower lid member 321 and the ring seat 330 are fixed to the anvil body 310 by a fixing member 340 such as a screw. Further, in order to maintain airtightness, an O-ring 350 for sealing is attached between the lower lid member 321 and the cylinder hole 311.

On the other hand, a disk-shaped plunger 360 is slidably accommodated in the enlarged diameter portion 311a of the cylinder hole 311 which is located on the upper side in the drawing, and the plunger rod 361 thereof is provided.
Is inserted into the cylinder of the cylindrical upper lid member 322 fitted in the expanded diameter portion 311a of the cylinder hole 311. The upper lid member 322 is a support holder 37 for a disk-shaped nondestructive strength tester mounted on the upper surface of the anvil body 310 in the figure.
It is fixed by 0. The support holder 370
Is attached to the anvil main body 310 by a fixture 340 such as a screw.
It is fixed to. Further, in order to maintain airtightness, a sealing O-ring 35 is provided between the upper lid member 322 and the cylinder hole 311, and between the upper lid member 322 and the plunger rod 361.
0 is attached.

The upper end surface side of the plunger rod 361 in the figure is used as a striking piece portion 362 which is striked by the plunger during a striking test by a nondestructive strength tester. The hitting piece portion 362 may be integrated with the plunger rod 361 as in this example, but may be replaceably attached as a separate metal piece as shown in FIG. 3, for example. For example, as shown in the figure, a male screw portion 362a may be provided on one side of the metal, and the male screw portion 362a may be screwed into the female screw portion 361a on the plunger rod 361 side. When screwing and releasing the screw, as shown in the figure, for example, a plurality of engaging holes 362b near the upper edge of the metal piece,
362b is provided, on which the locking claws 410, 4 of the tool 400 are provided.
It suffices to insert 10 to perform this.

Thus, if several metal pieces are prepared in advance, if the metal pieces are deformed or damaged over time, the metal pieces can be replaced without replacing the entire plunger 360 or the plunger rod 361. Only you can respond quickly. It is also possible to prepare and replace metal pieces made of metal material having different surface repulsion degrees in advance. Further, it is possible to form the striking piece portion 362 with another material having durability and reproducibility equivalent to metal. For example, a composite material including a plurality of materials can be given.

A cylindrical support guide 371 into which a nondestructive strength tester is introduced at the time of a hit test is fixed to the support holder 370. This support guide 371
It is preferable to provide an opening window 372 at the base (toward the lower side in the figure) so that the guided tip of the nondestructive strength tester can be visually observed. In addition, a protective material 373 such as felt (nonwoven fabric) may be provided in the cylinder. With these structures, the operator simply inserts the non-destructive strength tester into the support guide 371 during use,
It is possible to almost automatically occupy the striking piece portion 362 with the plunger at the tip portion thereof without damaging the testing machine side.

External pressurized oil is supplied to the cylinder chamber R through an oil supply passage 381 of the anvil body 310. As the supply pressure increases, the filling oil in the cylinder chamber R acts on the plunger 360 and the plunger rod 361 as a kind of rigid body, so that the repulsion degree of the striking piece portion 362 increases. That is, by adjusting the supply pressure, the resilience of the striking piece 362 can be varied. The oil can be discharged through the oil discharge passage 382 of the anvil body 310. The check valve 3 is provided on the oil supply passage 381 side.
Since 83 is provided, the pressure at the time of oil supply is maintained as it is. The pressure at this time is, for example, a pressure gauge 392 suitable for the external pressurized oil line 391.
You can easily know if you connect. The oil can be discharged from the oil discharge passage 382 by loosening the screw-type airtight cap 384, for example. Of course, it is also possible to use a valve mechanism.

The variable test anvil 300 having such a structure can be used alone by itself, but it is usually used as follows. First, in the test (test) of the non-destructive strength tester itself, as shown in FIG. 5, several (one unit is possible) non-destructive strength testers 100 are prepared, and a conventional type metal is used. For the test anvil 200 made of a lump, one impact test is performed for each unit, and the impact test is performed a plurality of times (for example, about 10 times), and the degree of repulsion is measured each time. Then, a product whose average value is within a value of 80 ± 2 (reference value) is selected as a passing product at the first level.

The internal structure of the nondestructive strength tester 100 is shown in FIG. In the figure, 110 is a portable cylindrical housing, 120 is an ippact spring, 130 is a hammer mass (weight), 140 is a guide bar for guiding the hammer mass 130, 150 is the tip of the guide bar 140 (lower end in the figure). ),
A plunger (striking culm) that moves forward and backward from the tip of the housing 110, 160 is a locking means for a hammer mass, which is a cam piece assembled to the rear end (upper end in the figure) of the guide bar 140, 170 is a rear end cap, and 171 is An adjusting part including a screw for adjusting the releasing position of the locking means 160, 1
Reference numeral 81 is an indicator piece showing the degree of repulsion, 182 is a locking button for restricting the return of the locking means 160 side for the hammer mass,
183 is a compression spring on the rear end cap 170 side, 1
Reference numeral 83 is a reality ring spring inserted between the inside of the cylinder of the plunger 150 and the tip of the guide bar 140, and 172 is a front end cap for fixing the cylindrical coupling 173 to which the front end of the ippact spring 120 is locked. is there.

In this structure, the plunger 150 is
Press on the surface of the concrete structure to be measured. Then, the plunger 150 is pushed back into the housing 110, the ippact spring 120 is extended therein, and the hammer mass 130 is also retracted to a predetermined position. When the hammer mass 130 reaches a predetermined position (operating position), its locking means 160
However, the hammer mass 130 violently rushes (forwards) due to the restoring force (accumulation pressure) of the ippact spring 120 because the hammer mass 130 is released by contacting the adjusting portion 171 of the rear end cap 170.
Then, the plunger 150 is struck and hit on the surface of the concrete structure. At the time of this impact, the hammer mass 130 is momentarily pushed back in accordance with the degree of surface resilience of the concrete structure. This return amount (repulsion) is indicated by the pointing piece 181.
The compressive strength of the concrete structure can be estimated by reading and measuring with.

Next, the variable test anvil 30 of the present invention.
For 0, oil is supplied at a predetermined pressure. Then, as described above, the filling oil that has flowed into the cylinder chamber R acts on the plunger 360 and the plunger rod 361 as a kind of rigid body, and the striking piece portion 362.
A predetermined degree of repulsion is given to. The degree of repulsion is about 30 (for example, a value of 30 ± 2). As described above, the value of about 30 is a value corresponding to the surface resilience when a general concrete structure is hardened at a predetermined compressive strength.

In this way, the variable test anvil 3 is
When the oil filling for 00 is completed, the non-destructive strength tester 100, which has passed the test anvil 200 made of the above-mentioned metal lump, is passed through the support guide 37 as shown in FIG.
Insert into No. 1 and perform a striking test. Also in this case, the impact test is performed a plurality of times (for example, about 10 times) per unit, the degree of repulsion at each time is measured, and the average value thereof is obtained. Then, a product whose value falls within a range of 30 ± 2 (reference value) is selected as a passing product at the second level.

In this way, the non-destructive strength tester 100, which has passed the first and second levels, is only the conventional test anvil 200 made of a metal ingot, as is apparent from the test data described later. Higher reliability can be obtained for models that passed the test.

Further, using the non-destructive strength tester 100 which has passed the first and second levels, an impact test is conducted on the surface of the concrete structure to be actually measured. In this case, the impact test is carried out by slightly shifting a plurality of places (for example, about 20 places) on the surface of the concrete structure per one unit, the resilience is measured each time, and the average value thereof is obtained. Then, if the average value is within about 30, it can be estimated with higher accuracy as if the concrete structure is hardened at a predetermined compressive strength.

It is to be noted that how much pressure is applied to the variable test anvil 300 of the present invention so that the repulsion degree of the hitting piece portion 362 becomes about 30 is as follows. To set. First, a non-destructive strength tester specially adjusted so as to obtain a resilience of about 30 when a impact test is performed on a concrete structure hardened at a predetermined compressive strength is prepared. Next, using this non-destructive strength tester, the variable test anvil 300 of the present invention is subjected to a striking test about 10 times, and the average value obtained by this is set as a pressure of around 30. To do. Here, the adjusted non-destructive strength tester is composed of carefully selected parts, and when a hit test is performed on the conventional test anvil 200 made of a metal ingot, the average value of the resilience is 80 ±. When the impact test is performed on a concrete structure that has a value of 2 (passed product at the above-mentioned first level) and is specially hardened at a predetermined compressive strength by construction, it is about 30 It is a tester that can obtain values.

Next, in order to clarify the action and effect of the present invention, test data conducted by the present inventors will be described.

First, a plurality of non-destructive strength testers (5 units, which have passed the conventional test anvil 200) have been passed.
By T _{1 to} T ₅ ), impact test is conducted at 20 locations on each surface of the same surface of a concrete structure that has been hardened with a prescribed compressive strength, with some displacement, and the rebound is measured each time. Then, the average value was obtained. The results are shown in Table 1. In the table, R ₈₀ is the resilience of the conventional test anvil 200 during the impact test, and CO
N is the degree of repulsion at the time of the impact test on the concrete structure.

[0036]

[Table 1]

From this Table 1, the conventional test anvil 2
In the impact test for 00, the value was within 80 ± 2 (reference value), and even in the non-destructive strength tester that was a passing product at the first level, depending on the model (T ₃ , T ₅ ), it was large. You can see that there are variations. This is basically because, on the same surface of the concrete structure, the impact points are slightly deviated, but since the average value of 20 points is calculated, the variation in the impact points is as follows: It is a size that is difficult to explain. In other words, even if the non-destructive strength tester that passed the first level product is used, it is found that there is a suspicion about its reliability.

Next, a plurality of non-destructive strength testers (5 units, T ₁ , T ₂₎ which passed both the conventional test anvil 200 and the variable test anvil 300 of the present invention.
The _{T 4 T 6, T 7)} , for the same surface of the concrete structure cured at a predetermined compression strength, per each table performs hitting test of 20 sites by shifting the bit position, the repulsion of the respective Was measured and the average value was calculated. The results are shown in Table 2. In the table, R ₈₀ is the resilience of the conventional test anvil 200 in the impact test, R ₃₀ is the resilience of the variable test anvil 300 of the present invention in the impact test, and CON is the concrete structure. It is the degree of repulsion during the impact test. The model (T ₁ ,
T ₂ and T ₄ ) are the same as those of the non-destructive strength tester that has passed the test with the conventional test anvil 200.

[0039]

[Table 2]

From this Table 2, the conventional test anvil 2
00 and the variable test anvil 300 of the present invention.
Multiple non-destructive strength testing machines (5 units,
T₁, T ₂, T_Four, T₆, T₇) Is used,
For the same surface of concrete structure cured by compressive strength
In the impact test, the value around 30 is
It turns out that it can be obtained. This is a traditional test
Both the building 200 and the variable test anvil 300 of the present invention.
When used together, it is more reliable and safer in accordance with the actual situation.
It can be seen that the specified non-destructive strength test results are obtained.

The nondestructive strength tester used in the present invention is the nondestructive strength tester 100 shown in FIG.
However, the present invention is not limited to the above, and can be applied to other testing machines having the same structure.

[0042]

As is apparent from the above description, the variable test anvil for a non-destructive strength tester for concrete or the like according to the present invention has the following excellent effects. (1) First, since the striking piece portion installed on one side of the anvil body is pressed and held from the inside of the anvil body with an appropriate pressure, the repulsion degree of the striking piece portion can be changed by changing the pressure. . (2) If a pressure applying mechanism such as hydraulic pressure is used, the resilience of the hitting piece can be appropriately changed relatively easily. . (3) By adjusting the pressure, the resilience of the hitting piece can be appropriately adjusted to a value of around 30 which is the surface resilience of an object such as concrete. That is, it is possible to make the repulsion degree close to the surface repulsion degree of the object to be measured. This provides a more reliable and stable measurement value. (4) If the hitting piece can be replaced, higher convenience can be obtained.

Further, according to the test method of the non-destructive strength tester according to the present invention, the following excellent effects can be obtained. That is, when testing a non-destructive strength tester such as concrete, the non-destructive strength tester makes the test anvil made of metal block and the impact repulsion of the anvil body almost equal to the object such as concrete. The impact test is performed on both the adjusted variable test anvil, and if these two rebounds are within the prescribed pass range, the non-destructive strength tester is passed with higher reliability. It can be a machine.

According to the non-destructive strength test method for concrete and the like according to the present invention, the following excellent effects are obtained. That is, in measuring the surface resilience of an object such as concrete, a non-destructive strength tester is used to make the test anvil made of metal block and the impact resilience of the anvil body almost equal to that of an object such as concrete. For both the variable test anvil and the adjusted test anvil, if the impact degree of these two is within a predetermined pass range, the nondestructive strength tester against the object such as concrete, Since the impact test is performed, more reliable and stable measurement results can be obtained as compared with the conventional test method using only the test anvil made of a metal ingot.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an example of a variable test anvil for a nondestructive strength tester for concrete or the like according to the present invention.

2 is a partially enlarged vertical side view of FIG.

FIG. 3 is a partial vertical cross-sectional side view showing an example in which the hitting piece portion is made of a separate metal piece.

FIG. 4 is a vertical cross-sectional side view showing an example of a nondestructive strength tester.

FIG. 5 is a side view showing a non-destructive strength tester and a conventional metal anodized test anvil.

[Explanation of symbols]

100 non-destructive strength tester 200 Test anvil made of metal 300 variable test anvil 310 Anvil body 311 Cylinder hole 321 Lower lid member 322 Top cover member 360 plunger 361 Plunger rod 362 Impact piece part 381 oil supply path 382 oil discharge path

Claims (7)

[Claims] 1. A non-destructive strength tester for concrete or the like characterized in that a striking piece portion is installed on one side surface of the anvil body, and the striking piece portion is pressed and held from the inside of the anvil body by appropriate pressure. Variable test anvil. 2. The variable test anvil for a non-destructive strength tester for concrete or the like according to claim 1, wherein the hitting piece portion is pressed and held by a pressure applying mechanism such as hydraulic pressure. 3. The striking piece portion is attached to a plunger rod of a cylinder incorporated in the anvil body, and pressurized oil is supplied from the outside into the cylinder to press and hold the striking piece portion. A variable test anvil for a non-destructive strength tester for concrete or the like according to claim 1. 4. The pressing force applied to the striking piece portion is adjusted so that the resilience thereof is substantially equal to the resilience of an object such as concrete.
Variable test anvil for non-destructive strength testers such as the concrete described. 5. The variable test anvil for a nondestructive strength tester for concrete or the like according to claim 1, wherein the hitting piece portion is replaceable. 6. When testing a non-destructive strength tester for concrete or the like, a non-destructive strength tester is used to perform a striking test on a test anvil made of metal lumps, and the degree of repulsion is obtained, while A repulsion test is performed on a variable-type test anvil in which the impact piece part installed on the side is pressed and held from the inside of the anvil body and its rebound is adjusted to be almost equal to an object such as concrete. A test method for a non-destructive strength tester, characterized in that the non-destructive strength tester is determined to be a passing machine when both repulsion degrees are within a predetermined acceptable range. 7. In measuring the surface resilience of an object such as concrete, a non-destructive strength tester is used to perform a striking test on a test anvil made of metal lumps to determine the resilience of the anvil body. A hitting test is performed on a variable test anvil in which the impact piece part installed on one side is pressed and held from the inside of the anvil body, and the degree of repulsion is adjusted to be almost the same as an object such as concrete. If these two rebounds are within a predetermined pass range, the non-destructive strength tester performs an impact test on an object such as concrete, and the concrete is characterized in that the rebound is obtained. Non-destructive strength test method.