JP4807744B2 - Judgment method and judgment device of mixing amount of organic fiber in fresh concrete - Google Patents

Description

The present invention relates to a quality determination technique for the amount of organic fibers mixed in concrete (fresh concrete) in which organic fibers are mixed and not yet hardened.

  It is known that high-strength concrete is likely to explode during a fire. In addition, when concrete is used in an environment where the temperature is likely to rise rapidly, such as a tunnel, the concrete may explode in the event of a fire. In order to prevent such concrete explosion, a method of mixing organic fibers such as polypropylene into concrete has been proposed (Patent Document 1).

  In such concrete, it is necessary to ensure safety by inspecting whether organic fibers are mixed in an appropriate amount and uniformly. In the conventional inspection method, the test method of the JIS A 1103 aggregate fine particle amount test method is applied. First, a quantitative sample collected from fresh concrete is dispersed in water and passed through multiple types of sieves. The organic paste is taken out by gradually removing the cement paste. And after drying this taken-out organic fiber, a weight is measured and the quality determination is performed based on the measurement result of a weight.

JP-A-8-189080

  However, the conventional inspection method not only requires several hours for the sieving operation, but also takes time for drying the taken-out organic fiber, so that there is a problem that the inspection time becomes long as a whole. Another problem is that a portion of the organic fiber is washed away during the sieving operation, and the inspection accuracy is not necessarily high.

Therefore, an object of the present invention is to accurately determine whether or not the amount of organic fibers mixed in fresh concrete mixed with organic fibers is accurate in a short time.

According to the present invention, fresh concrete mixed with organic fibers, and a liquid having a specific gravity higher than that of organic fibers in the previous period and a specific gravity lower than that of cement and aggregate of the fresh concrete, have a relative cross-sectional area of the container. A charging step for charging into the large first part ;
A dispersion step of dispersing the fresh concrete into the liquid by stirring or shaking in the container first portion;
A lid mounting step of mounting a third portion serving as a lid of the container first portion and a second portion having a smaller cross-sectional area than the first portion connected to the first portion on the container first portion;
A liquid replenishing step of replenishing the liquid from the container second part which is an upper part of the lid;
Determining the quality of the organic fiber mixed in the fresh concrete according to the thickness of the organic fiber layer formed by the organic fibers separated and floated from the fresh concrete;
A method for determining whether or not the amount of organic fibers mixed in fresh concrete is good is provided.

  In this inspection method, the cement and the aggregate are separated from each other by using the organic fiber floating. The time required for the separation can be greatly reduced as compared with the case of using a sieve. And since the thickness of the said organic fiber layer is proportional to the mixing amount of the said organic fiber in the said fresh concrete, it can be judged from the said thickness whether the mixing amount of the said organic fiber is appropriate. Since the organic fibers are accommodated in the container, the organic fibers are not washed away as in the case of using a sieve, and the inspection accuracy can be improved. In addition, since the organic fibers need not be dried, the inspection time can be shortened. Thus, according to the inspection method of the present invention, it is possible to accurately inspect a fresh concrete mixed with organic fibers in a short time.

In the present invention, the first-stage container has a first portion having a relatively large cross-sectional area and a second portion having a relatively small cross-sectional area above the first-stage first portion, and the first-order liquid is a first-order organic fiber. Since the layer is introduced into the container in the amount corresponding to the amount formed in the second part of the previous period, the first part of the first part contributes to securing a larger space as a storage space for the fresh concrete and the liquid in the previous period. The portion contributes to ensuring a thickness that can be easily determined as the thickness of the organic fiber layer in the previous period.

In the present invention, since the container is capable of separating the second portion and the first portion to facilitate the insertion of the fresh concrete and the liquid to said first portion.

Further, in the present invention, the container has a plurality of holes and is provided with a regulating member that regulates the rising of the floating organic fiber . Therefore, the upper limit of the organic fiber layer is the regulating member, The input amount may not be accurate, and the thickness of the organic fiber layer can be easily determined.

Moreover, in this invention, since the said container is displayed under the said control member and has the parameter | index which determines the thickness of an organic fiber layer in the previous period, the quality determination of the said fresh concrete can be performed easily only by visual observation.

  Moreover, in this invention, the structure which is at least any one of the process which stirs the said liquid and fresh concrete or vibrates the said liquid and fresh concrete can be employ | adopted in the said dispersion | distribution process. According to this configuration, the dispersion of the fresh concrete into the liquid is promoted, and the inspection time can be shortened.

In addition, according to the present invention, as a determination tool suitable for the determination method, a determination device for determining the amount of organic fiber mixed in fresh concrete mixed with organic fibers, the specific gravity being higher than that of the fresh concrete and the organic fiber. And a container containing a liquid having a lighter specific gravity than the fresh concrete and the aggregate, and the first container has a relatively large cross-sectional area, and a relatively large cross-sectional area above the first part. Having a small second portion, and a third portion between the first portion and the second portion, the third portion being formed integrally with the second portion and having a cross-sectional area thereof Is gradually reduced from the first part side toward the second part side, and a rugged skin-like unevenness is provided on the inner surface thereof , and the first part and the second and third parts And are separable from each other Ri, the upper outer peripheral surface of the first portion and the Yes and engraved screws on the lower inner peripheral surface of the third portion, the second portion is at least partially upwardly and downwardly opened is composed of a transparent material a tubular body are made of a regulating member which partitions vertically having a plurality of holes, the determination device at least one indicator line is characterized by being facilities are provided on the outer circumferential surface of the previous term cylindrical body The

As described above, according to the present invention, it is possible to accurately determine whether or not the amount of organic fiber mixed in fresh concrete mixed with organic fiber is good in a short time.

<First Embodiment>
A concrete inspection method according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. First, as shown in FIG. 1A, a container 10, a fresh concrete sample 20 and a liquid 30 are prepared. The container 10 has a bottomed cylindrical body that is open at the top. The container 10 is made of, for example, resin, and is made of a transparent material (for example, a colorless and transparent, colored transparent material) whose inside can be seen through from the outside. The container 10 may be a cylindrical body or a rectangular cylinder, but is a cylindrical body in the present embodiment.

  The sample 20 is taken from fresh concrete mixed with organic fibers to be inspected, and is obtained by kneading the cement paste 21, the aggregate 22 and the organic fibers 23. A sample 20 is taken in a predetermined amount from fresh concrete produced on site. The aggregate 22 includes fine aggregates such as sand and coarse aggregates such as pebbles. The organic fiber 23 is made of, for example, polypropylene, and is mixed to suppress concrete explosion.

  The liquid 30 is a liquid having a specific gravity heavier than that of the organic fiber 23 and lighter than that of the cement and the aggregate 22 constituting the cement paste 21. Generally, the specific gravity of cement is 3 or more, and the specific gravity of aggregate is 2.5 or more. When polypropylene is used as the organic fiber 23, the specific gravity is about 0.9. Therefore, for example, water can be used as the liquid 30. In order to increase the specific gravity difference between the liquid 30 and the organic fiber 23, the liquid 30 can be made to have a larger specific gravity by dissolving a specific gravity adjusting agent such as salt.

  Next, as shown in FIG. 1B, the sample 20 and the liquid 30 are put into the container 10. Subsequently, the sample 20 is dispersed in the liquid 30 in the container 10. In order to promote the dispersion of the sample 20, as shown in FIG. 1C, the liquid 30 and the sample 20 in the container 10 are stirred by the stirring rod 1 or the like, and the liquid 30 and the sample 20 are shaken by the shaker 2 or the like. It is desirable to perform at least one of the following. The organic fiber 23 adhering to the stirring rod 1 or the like is washed out in the container 10 with a small amount of liquid 20. In order to promote the dispersion of the sample 20, it is desirable to mix a dispersion accelerator such as a surfactant in the liquid 30. This contributes to shortening the inspection time.

  When the sample 20 is dispersed in the liquid 30 and is left as it is, the mixture of the aggregate 22 and the cement 21 ′ is caused by the difference in specific gravity from the liquid 30 as shown in FIG. While sedimenting at the bottom, the organic fibers 23 float and collect at the top of the liquid 30 to form an organic fiber layer 23 '. It is desirable that an antifoaming agent is mixed in the liquid 30 so that an organic fiber layer 23 ′ in which the organic fibers 23 are densely assembled is formed.

  Accordingly, as shown in FIG. 2 (b), the thickness (height) d of the organic fiber layer 23 'is measured to determine the content of the organic fiber 23 in the sample 20. If the content of the organic fiber 23 is not less than the specified value, the fresh concrete can be determined as a non-defective product, and if it is less than the specified value, it can be determined as a defective product. That is, since the thickness d of the organic fiber layer 23 ′ is proportional to the amount of organic fibers 23 in the fresh concrete, it can be determined from the thickness d whether the amount of organic fibers 23 is appropriate. Moreover, it can also be judged whether the organic fiber 23 is mixed uniformly by extract | collecting the some sample 20 from fresh concrete and performing the said test | inspection.

  Although the approximate value of the content of the organic fiber 23 can be calculated from the cross-sectional area of the container 10 and the thickness d, the relationship between the cross-sectional area of the container 10 and the amount of the sample 20 is known in advance. It is easy to determine whether fresh concrete is good or not based on whether the thickness exceeds a predetermined value.

  As described above, in the inspection method of the present embodiment, the cement 21 ′ and the aggregate 22 are separated from each other by utilizing the precipitation of the organic fibers 23. The time required for the separation can be greatly reduced as compared with the case of using a sieve. And since the organic fiber 23 is accommodated in the container 10, the organic fiber 23 is not poured away like the case where a sieve is used, but it can improve inspection accuracy. Moreover, since the organic fiber 23 does not need to be dried, the inspection time can be shortened. Thus, according to the inspection method of this embodiment, the inspection of fresh concrete mixed with organic fibers can be accurately performed in a short time.

Second Embodiment
In the first embodiment, the container 10 has a uniform cross-sectional area in the vertical direction. If the cross-sectional area of the container 10 is large, the sample 20 and the liquid 30 can be charged and dispersed easily. However, the thickness of the organic fiber layer 23 'is not uniform or the thickness is measured. It may be difficult. Therefore, in this embodiment, containers having different cross-sectional areas are used. 3 and 4 are explanatory views of a concrete inspection method according to the second embodiment of the present invention.

  FIG. 3A shows the container 110 used in this embodiment. The container 110 includes a main body portion 111 and a lid portion 112 and can be separated from each other. The main body 111 has the same configuration as that of the container 10 described above, and forms a bottomed cylindrical body that is open at the top. The main body 111 constitutes a first portion having a relatively large cross-sectional area in the container 110.

  The lid portion 112 has a cylindrical body that is open at the top and bottom. The lid portion 112 is made of, for example, resin and is made of a transparent material that allows the inside to be seen through from the outside. The lid portion 112 includes an upper end portion 112a that is a second portion having a relatively small cross-sectional area in the container 110, and a tapered portion 112b that is formed integrally with the lower portion of the upper end portion 112a. It is desirable that the inner surface of the tapered portion 112b is provided with a rugged skin-like unevenness so that the organic fiber 23 is less likely to adhere to the inner surface of the tapered portion 112b.

  On the outer peripheral surface of the upper end portion 112a, index lines 113 and 114 spaced apart from each other are provided. The index line 113 is an index of the liquid level position of the liquid 30. The index line 114 is an index for determining the thickness of the organic fiber layer 23 '. In the present embodiment, it is assumed that the entire lid 112 is made of a transparent material in which the inside can be seen through from the outside, but at least the portion between the index line 113 and the index line 114 may be a transparent material.

  The taper portion 112b gradually decreases in cross-sectional area from the body portion 111 side which is the first portion toward the upper end portion 112a side which is the second portion. In the case of this embodiment, the cross-sectional area of the taper portion 112b continuously changes so as to substantially match the cross-sectional area of the main body portion 111 at the lower portion thereof and to match the cross-sectional area of the upper end portion 112a at the upper portion thereof. .

  In the case of this embodiment, the main body 111 and the lid 112 are configured such that the lower portion of the lid 112 is fitted to the upper portion of the main body 111, but the upper outer peripheral surface of the main body 111 and the lid 112 It is good also as a screwing structure which engraved the screw in the lower inner peripheral surface.

  Next, the inspection method in this embodiment will be described. First, the main body 111 and the lid 112 are separated, and the sample 20 and the liquid 30 are put into the main body 111 as shown in FIG. Subsequently, the sample 20 is dispersed in the liquid 30 in the main body 111. In order to promote the dispersion of the sample 20, as in the first embodiment, as shown in FIG. 3C, the liquid 30 in the main body 111 and the sample 20 are stirred by the stirring rod 1 and the shaker 2 It is desirable to perform at least one of the vibration of the liquid 30 and the sample 20 by, for example. Further, as in the first embodiment, it is desirable that the liquid 30 is mixed with a dispersion accelerator such as a surfactant or an antifoaming agent.

  After the sample 20 is dispersed in the liquid 30, the lid portion 112 is attached to the main body portion 111 as shown in FIG. Subsequently, the liquid 30 is replenished into the container 110 from the upper end of the lid 112. As shown in FIG. 4B, the liquid 30 is replenished until the liquid level reaches the index line 113. That is, the liquid 30 is replenished by the amount that the organic fiber layer 23 ′ is formed in the upper end portion 112 a.

  After the liquid 30 is replenished, the organic fiber 23 attached to the inner surface of the tapered portion 112b is caused to float by lightly striking the tapered portion 112b or lightly vibrating the container 10, as shown in FIG. In addition, almost the entire amount of the organic fiber 23 floats and gathers at the top of the liquid 30 to form the organic fiber layer 23 ′.

  Therefore, when the organic fiber layer 23 ′ is formed even below the index line 114, fresh concrete can be determined as a non-defective product, and when the organic fiber layer 23 ′ does not reach the index line 114, it can be determined as a defective product.

  According to this embodiment, the main body 111 secures a larger space as a storage space for the fresh concrete sample 20 and the liquid 30, while the upper end 112a has a thickness that facilitates inspection as the thickness of the organic fiber layer 23 ′. Can be secured. Further, by adopting a configuration in which the main body 111 and the lid 112 can be separated, it is possible to facilitate the operation of charging and separating the fresh concrete sample 20 and the liquid 30 into the main body 111.

  Further, by providing the index line 114, the quality of fresh concrete can be determined simply by visual observation. Furthermore, the provision of the tapered portion 112b also has an effect that the organic fiber 23 that floats easily collects in the upper end portion 112a.

<Third Embodiment>
In the second embodiment, the liquid 30 needs to be replenished in accordance with the index line 113, and an operation for matching the liquid surfaces of the index line 113 and the liquid 30 is necessary. This embodiment makes such work unnecessary. FIGS. 5A and 5B are explanatory views of a concrete inspection method according to the second embodiment of the present invention, and FIG. 5A shows a container 210 used in the present embodiment. The container 210 is obtained by adding a regulating member 220 to the container 110 of the second embodiment. In FIG. 5A, the same components as those of the container 110 are denoted by the same reference numerals and description thereof is omitted.

  The regulating member 220 is disposed in the upper end portion 112 a at the position of the index line 113 in the container 110. The restriction member 220 is a partition member in which a plurality of holes 221 are formed and partitions the internal space of the upper end portion 112a up and down. In the case of the present embodiment, the restricting member 220 is formed integrally with the upper end portion 112a, but may be configured to be fixed in the upper end portion 112a as a separate member.

  The procedure of the inspection method using the container 210 is the same as that in the second embodiment. The liquid 30 can pass through the restriction member 220 by passing through the hole 221, but the organic fiber 23 cannot pass through the hole 221, and therefore cannot pass through the restriction member 220. For this reason, as shown in FIG. 5B, the rising of the organic fiber 23 that has floated is regulated by the regulating member 220, and the upper limit of the organic fiber layer 23 ′ is the lower surface of the regulating member 220. The replenishment of the liquid 30 may be performed so that the liquid level exceeds the regulating member 220, and the amount may not be accurate. Further, since the thickness of the organic fiber layer 23 ′ can be observed using the regulating member 220 as a guide, the thickness can be easily determined.

(A) thru | or (c) is explanatory drawing of the inspection method of the concrete which concerns on 1st Embodiment of this invention. (A) And (b) is explanatory drawing of the inspection method of the concrete which concerns on 1st Embodiment of this invention. (A) thru | or (c) is explanatory drawing of the inspection method of the concrete which concerns on 2nd Embodiment of this invention. (A) thru | or (c) is explanatory drawing of the inspection method of the concrete which concerns on 2nd Embodiment of this invention. (A) And (b) is explanatory drawing of the inspection method of the concrete which concerns on 3rd Embodiment of this invention.

Explanation of symbols

10, 110, 120 Container 20 Sample 21 Cement paste 22 Aggregate 23 Organic fiber 30 Liquid

Claims (2)

Fresh concrete mixed with organic fibers and a liquid having a higher specific gravity than the organic fibers in the previous period and a lower specific gravity than the cement and aggregate of the fresh concrete are contained in the first portion of the container having a relatively large cross-sectional area. Input process to input,
A dispersion step of dispersing the fresh concrete into the liquid by stirring or shaking in the container first portion ;
A lid mounting step of mounting a third portion serving as a lid of the container first portion and a second portion having a smaller cross-sectional area than the first portion connected to the first portion on the container first portion;
A liquid replenishing step of replenishing the liquid from the container second part which is an upper part of the lid;
Determining the quality of the organic fiber mixed in the fresh concrete according to the thickness of the organic fiber layer formed by the organic fibers separated and floated from the fresh concrete;
A method for determining the quality of organic fibers mixed in fresh concrete. A determination instrument used to determine the quality of organic fibers mixed in fresh concrete mixed with organic fibers ,
A container containing a liquid having a specific gravity heavier than that of the fresh concrete and the organic fiber and a specific gravity lighter than the cement and aggregate of the fresh concrete;
The container is
A first portion having a relatively large cross-sectional area; a second portion having a relatively small cross-sectional area above the first portion; and a third portion between the first portion and the second portion. Have
Said third portion, said second portion and formed integrally, and its cross-sectional area are gradually reduced toward the second portion side from the first portion side, and, on its inner surface citron Skin-like irregularities are provided,
The first part and the second and third parts are separable from each other, and screws are formed on the upper outer peripheral surface of the first part and the lower inner peripheral surface of the third part,
The second part is composed of a cylindrical body made of at least a part of a transparent material whose upper and lower parts are open, and a regulating member that is divided into upper and lower parts having a plurality of holes, and is formed on the outer peripheral surface of the previous cylindrical body. determining instrument, characterized in that at least one index line is facilities are.

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