JP6118490B2 - Medium fluidity concrete - Google Patents

Description

  The present invention relates to medium fluidity concrete.

  Conventionally, as concrete for tunnel lining, ordinary concrete having a slump of 15 cm to 21 cm or a slump flow of less than 35 cm has been used. Since this ordinary concrete has low fluidity, there is a risk of insufficient filling in the mold.

  Therefore, in recent years, there have been increasing cases of using high fluidity concrete (slump flow larger than 50 cm) having high fluidity and excellent filling properties. However, since the high fluidity concrete has high fluidity, material separation of the coarse aggregate is likely to occur. In order to prevent this, a large amount of hydraulic binder such as cement may be used or a material separation preventing agent may be used, but there is a problem that the material cost increases. Furthermore, since a special material such as a material separation preventing agent is used, there is a problem that it takes time and effort for manufacturing management.

  Therefore, recently, medium-fluidity concrete (slump flow of 35 cm or more and 50 cm or less), which has better fluidity than ordinary concrete, is lower in cost than high-fluidity concrete, and easy in quality control, has come to be used ( Patent Document 1).

For example, Non-Patent Document 1 describes the standard performance of medium-fluidity concrete as shown in FIG. 1, and in order to ensure this standard performance, it is added to ordinary concrete (cement 270 kg / m ³ or more). It is recommended to add cement (page 5 of Non-Patent Document 1).

JP 2008-285843 A

Tunnel construction management guidelines (Middle fluid lining concrete), East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd., West Japan Expressway Co., Ltd., August 2008

  However, the above-described method of adding additional cement has a problem in that the temperature of concrete after placing increases due to an increase in the amount of cement, which may promote the occurrence of temperature cracks.

  Then, this invention is made | formed in view of said problem, and it aims at providing the medium fluidity concrete which can be manufactured, suppressing the compounding ratio of hydraulic binders, such as cement, similarly to normal concrete. .

The medium fluidity concrete of the present invention is a mixture of water and a hydraulic binder, and has a paste of 300 liters / m ³ or more and 330 liters / m ³ or less, and 280 liters / m ³ or more and 360 liters / m ³ or less. Contains coarse aggregate and thickener component-containing high-performance AE water reducing agent , U-type filling height (in the case of no obstacles) is 28.5 cm or more , and the slump flow of the slump flow test was vibrated. during state, and are the 7cm or 13cm or less the amount of increase in slump flow of pressurized Funochi against vibration previous slump flow, the mixing ratio with respect to the hydraulic binder of the thickener components contain high AE water reducing agent 0 .5 wt% or more and 1.8 wt% or less .

  Moreover, in this invention, the mixture ratio with respect to the said hydraulic binder of the said water is good also as 45 weight% or more and 70 weight% or less.

  Moreover, the medium fluidity concrete of this invention is good also as containing 3 to 6 volume% of air.

  In the present invention, the hydraulic binder may be cement, or may contain cement and an admixture. In this case, the admixture may be fly ash, blast furnace slag, or limestone fine powder.

  Furthermore, in the present invention, the high performance AE water reducing agent may be a high performance AE water reducing agent containing a thickener component.

  ADVANTAGE OF THE INVENTION According to this invention, the medium fluidity concrete which can be manufactured can be provided, suppressing the compounding ratio of hydraulic binders, such as cement, similarly to normal concrete.

It is a figure which shows the range of the slump flow of the medium fluidity concrete which concerns on this embodiment, the amount of vibration deformation, and U type filling height. It is a list figure which shows each material contained in the test bodies 1-15 which concern on this embodiment, and those compounding ratios. It is a figure which shows the determination result of whether the slump flow of the test bodies 1-15 which concern on this embodiment, the amount of vibration deformation, the U-type filling height, and the performance of medium fluidity concrete are satisfy | filled. It is a list figure which shows each material contained in the test body 4 concerning this embodiment, and the test bodies 16-18, and those compounding ratios. It is a figure which shows the determination result of whether the slump flow of the test bodies 16-18 which concern on this embodiment, the amount of vibration deformation, U-type filling height, and the performance of medium fluidity concrete are satisfy | filled.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  In the present embodiment, as shown in FIG. 1, the concrete satisfying the conditions that the slump flow is 35 cm or more and 50 cm or less, the vibration deformation amount is 10 ± 3 cm, and the U-type filling height (when there is no obstacle) is 28 cm or more. The mixing ratio of each material for realizing fluidized concrete and realizing the medium fluidized concrete will be described.

The medium fluidity concrete according to the present invention is a mixture of water and a hydraulic binder, and (A) a paste of 300 liters / m ³ or more and 330 liters / m ³ or less, and (B) 280 liters / m ³ or more. It is produced by mixing a coarse aggregate of 360 liters / m ³ or less and (C) a high-performance AE water reducing agent having a thickener. In such a case, (D) the blending ratio of water contained in the paste with respect to the hydraulic binder is preferably 45% by weight or more and 70% by weight or less, and (E) the hydraulic binder of the high-performance AE water reducing agent. The blending ratio with respect to is preferably 0.5% by weight or more and 1.8% by weight or less. And (F) 3 to 6 volume% of air is contained in the manufactured middle fluidity concrete.

<About Paste (above (A))>
The paste is produced by mixing water and a hydraulic binder. In this embodiment, cement is used as the hydraulic binder.
In the present embodiment, the volume of the paste is the sum of the volumes of water, cement, and air mixed when the water and the cement are mixed.
In general, when handling water or cement, the weight is often measured rather than the volume. Therefore, when blending, the weight of water or cement is measured and the value is converted into the volume. Good. When converting, the volume of water and cement is calculated using the density of water and cement measured in advance. For example, in the case of the test body 5 of FIG. 2 described later (details will be described later), the weight and density of water are 175 kg / m ³ and 1.0 g / cm ³ , respectively, so the volume of water is (175 kg / m ³ ) ÷ (1.0 g / cm ³ ) = 175 liter / m ³ , and the cement weight and density are 300 kg / m ³ and 3.16 g / cm ³ , respectively. m ³ ) ÷ (3.16 g / cm ³ ) = 95 liter / m ³ .
At this time, the weight of the cement is set to be approximately the same as the weight calculated from the blending ratio of cement contained in general ordinary concrete. Furthermore, it is preferable to adjust the weight of water (that is, water-cement ratio) within the range shown in the above (D) with respect to the weight of the cement. And when mixing water and cement, the compounding quantity of water is adjusted so that the compounding ratio of a paste may be in the range shown by said (A).
Then, when water and cement are mixed, the content ratio of air contained in the paste is the same as the content ratio of air when producing general concrete with respect to the concrete volume to be produced (F) It is preferable to be within the range indicated by. At this time, when the air content ratio is less than 3% by volume which is the lower limit of the range shown in (F) above, an air content adjusting agent may be added to increase the air content ratio. The blending amount of the air amount adjusting agent is generally 0.006% by weight or less with respect to the weight of the cement contained in the paste. For example, in the case of the test body 5 of FIG. 2, the air content ratio was 4.5 vol% (that is, 45 liters / m ³ ) by adding 0.0025 wt% of the air amount adjusting agent. On the other hand, when the content ratio of the air contained in the paste is larger than 6% by volume which is the upper limit of the range shown in the above (F), the amount of the air amount adjusting agent added is reduced.
Since the amount of air contained in the paste and the amount of air contained in the concrete produced by mixing each material are substantially the same, the amount of air contained in the produced concrete may be confirmed.
In the case of the test body 5 shown in FIG. 2, since the mixing ratio of water and cement and the content ratio of air are 175, 95, and 45 liters / m ³ , as described above, the paste volume is the sum of these. 315 (= 175 + 95 + 45) liters / m ³ .

<About coarse aggregate (above (B))>
As with water and cement, when handling coarse aggregates, the weight is often measured rather than the volume, so when blending, measure the weight of the coarse aggregate and convert the value to volume. Also good. For example, in the case of the test body 5 shown in FIG. 2, the weight and density of the coarse aggregate are 745 kg / m ³ and 2.66 g / cm ³ , respectively, so the volume of the coarse aggregate is (745 kg / m ³ ) ÷ (2. 66 g / cm ³ ) = 280 liters / m ³ .
Further, in the same manner as the coarse aggregate, the fine aggregate may measure the weight of the fine aggregate and convert the value into the volume. For example, in the case of the test body 5 in FIG. 2, the weight and density of the fine aggregate are 1061 kg / m ³ and 2.62 g / cm ³ , respectively, so the volume of the fine aggregate is (1061 kg / m ³ ) ÷ (2.62 g / Cm ³ ) = 405 liter / m ³ .
For example, the volumes of the paste, fine aggregate, and coarse aggregate of the test body 5 in FIG. 2 are 315, 405, and 280 liters / m ³ , respectively, and when these values are added up, 1000 (= 315 + 405 + 280) liters / m ^3. become.

<About high performance AE water reducing agent (above (C))>
In this embodiment, a high-performance AE water reducing agent containing a thickener component was used as the high-performance AE water reducing agent. The high-performance AE water reducing agent containing the thickener component has the function of a thickener and has a water reducing performance of about 18% or more.
The blending ratio of the thickener component-containing high-performance AE water reducing agent to the cement is preferably 0.5 wt% or more and 1.8 wt% or less within the range shown in (E) above.

  Once the blending ratio of each material is determined to be within the range indicated by the above (A), (B), (D) to (F), cement, fine aggregate and coarse aggregate according to the blending ratio. Is added to a forced biaxial kneader and mixed, and then mixed with water, the above-mentioned (C) thickener component-containing high-performance AE water reducing agent, and an air amount adjusting agent. Manufacture concrete.

  Since it was confirmed through experiments whether or not the concrete produced by mixing at the above-mentioned blending ratio can satisfy the performance of the medium fluidity concrete shown in FIG. 1, it will be described below as an example.

<Example>
A plurality of concrete specimens (hereinafter referred to as specimens) having different blending ratios of the respective materials were manufactured, and the performance of these specimens was confirmed. In addition, the test body which is an Example which manufactured what made any one material out of the range of the compounding ratio mentioned above among a plurality of materials contained in a test object as a comparative example, and was compounded with the compounding ratio mentioned above, and Compared. First, the blending ratio of the materials included in each test body will be described, and then the performance confirmation result of each test body will be described.

FIG. 2 is a list showing the materials included in the test bodies 1 to 15 according to the present embodiment and their blending ratios.
As shown in FIG. 2, water, cement, coarse aggregate, fine aggregate, thickener component-containing high-performance AE water reducing agent or AE water reducing agent, and air amount adjusting agent at a predetermined ratio. By blending, 15 types of test bodies 1 to 15 were produced. Hereinafter, each test body 1-15 is demonstrated with reference to FIG.

  The test bodies 1-15 were adjusted so that the range shown by said (D) and (F) about the water cement ratio and the content rate of air might be satisfy | filled. Specifically, the water cement ratio and the air content ratio were adjusted to 45 to 70% by weight and 3 to 6% by volume, respectively.

<About Specimen 1>
The test body 1 is ordinary concrete containing water, cement, coarse aggregate, fine aggregate, AE water reducing agent, and air amount adjusting agent.
This test body 1 satisfies the ranges shown in the above (A), (B), (D), and (F) in the blending ratio of the paste, the blending ratio of the coarse aggregate, the water cement ratio, and the air content ratio. It is a comparative example which does not contain the high performance AE water reducing agent which has the thickener shown by said (C).
In addition, although the general AE water reducing agent contained in the test body 1 has the water reducing performance of about 10 to 12%, it does not have the function of the thickener.

<About Specimens 2-15>
Test bodies 2 to 15 include a thickener component-containing high-performance AE water reducing agent instead of the AE water reducing agent contained in ordinary concrete.
Further, the total weight of the fine aggregate and the coarse aggregate included in the test bodies 2 to 15 is substantially the same as the total weight of the fine aggregate and the coarse aggregate included in the normal concrete of the test body 1. It was adjusted. For example, the total weight of fine aggregate included in the test body 1 and (862kg / ^{m 3)} coarse aggregate and ^{(948kg / m 3) (1810kg} / m 3), fine aggregate included in the specimen 5 (1061kg total weight of / ^{m 3)} and coarse aggregate (745kg / ^{m 3)} and (1806kg / ^{m 3),} but was adjusted to be approximately the same.

The test bodies 2 to 6 satisfy the ranges shown in the above (A) and (D) to (F) for the blending ratio of the paste, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio. It adjusts and changes the mixture ratio of a coarse aggregate with the case where the range shown by said (B) is satisfy | filled, and the case where it is not satisfy | filled.
Specifically, the paste mixing ratio, water cement ratio, high-performance AE water reducing agent mixing ratio, and air content ratio are 315 liters / m ³ , 58%, 1.1 wt% to 1.4 wt%, respectively. , Adjusted to 4.5% by volume. Moreover, the mixing ratio of the coarse aggregate of the test bodies 2-6 was adjusted to 377, 356, 324, 280, 360 liters / m ³ , respectively, and the test body 2 was a comparative example outside the range shown in (B) above. Specimens 3 to 6 were examples within the range shown in (B) above.

The test bodies 7-11 satisfy | fill the range which showed the blending ratio of the coarse aggregate, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio in the above (B) and (D) to (F). Thus, the blending ratio of the paste is changed depending on whether the range shown in (A) is satisfied or not.
Specifically, the blending ratio of coarse aggregate, water cement ratio, blending ratio of high-performance AE water reducing agent, and air content ratio are 324 liter / m ³ or more and 333 liter / m ³ or less, 58%, 0.8 It was adjusted to 4.5% by volume or more and 2.0% by weight or less. Moreover, the compounding ratio of the paste of the test bodies 7-11 was adjusted to 306, 297, 289, 300, 330 liters / m ³ , respectively, and the test bodies 8 and 9 were comparative examples outside the range shown in the above (A). Specimens 7 and 10 to 11 were examples within the range shown in (A) above.

The test bodies 12 and 13 are the above-mentioned (A), (B), (D) to (F) with respect to the blending ratio of the paste and coarse aggregate, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio. It adjusts so that the range shown by (4) may be satisfy | filled, and is the Example which mix | blended the water cement ratio with the lower limit and upper limit of the range shown by said (C).
Specifically, the blending ratio of paste, coarse aggregate, high-performance AE water reducing agent, and air content ratio are 315 liters / m ³ , 324 liters / m ³ , 0.5 wt% to 1.8 wt%, respectively. , Adjusted to 4.5% by volume. Moreover, the water cement ratio of both the test bodies 12 and 13 was adjusted to 45 and 70% which are a lower limit and an upper limit, respectively.

The test bodies 14 and 15 are the above-mentioned (A), (B), (D) to (F) with respect to the blending ratio of the paste and coarse aggregate, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio. It adjusts so that it may satisfy the range shown, and it is the Example which mix | blended the content rate of air with the upper limit and lower limit of the range shown by said (F).
Specifically, the blending ratio of paste and coarse aggregate, water cement ratio, and blending ratio of high-performance AE water reducing agent were adjusted to 315 liter / m ³ , 324 liter / m ³ , 58%, and 1.0% by weight, respectively. did. Further, the blending amount of the air amount adjusting agent is 0.006 with respect to the weight of the cement so that the air content ratios of both the specimens 14 and 15 are the upper limit value and the lower limit value of 6 and 3% by volume, respectively. , Adjusted to 0 wt%.

  In addition, among the test bodies 2 to 13, the test bodies 2 to 6 and 9 to 13 were mixed with an air amount adjusting agent to adjust the air content ratio to 4.5% by volume. As for the air content ratio became 4.5 vol% just by mixing water, cement, fine aggregate, coarse aggregate and thickener component-containing high-performance AE water reducing agent, the air amount adjusting agent Were not mixed.

FIG. 3 is a diagram illustrating a determination result of whether or not the slump flow, the amount of vibration deformation, the U-type filling height, and the performance of the medium fluidity concrete of the test bodies 1 to 15 according to the present embodiment are satisfied.
As shown in FIG. 3, the slump flow, the vibration deformation amount, and the U-shaped filling height of the test bodies 1 to 15 were measured. Hereinafter, the measurement results of the respective test bodies 1 to 15 will be considered with reference to FIG.

  Since the test body 1 is ordinary concrete, neither the slump flow nor the U-type filling height satisfies the performance required as a medium fluidity concrete.

<About coarse aggregate: Evaluation results of specimens 2 to 6>
The specimen 2 (comparative example) with a 377 liter / m ³ ratio of the coarse aggregate out of the range shown in the above (B) has a slump flow of 39.5 cm and is required as a medium fluidized concrete of 35 cm. Although the above conditions of 50 cm or less are satisfied, the amount of vibration deformation and the U-type filling height are 15.5 cm and 25.0 cm, respectively, and the amount of vibration deformation required for medium-fluid concrete is 10 ± 3 cm, The U-type filling height does not satisfy both conditions of 28 cm or more.
On the other hand, the specimens 3 to 6 (Examples) having 356, 324, 280, 360 liter / m ³ in which the blending ratio of the coarse aggregate is within the range shown in the above (B) are slump flow, vibration deformation amount, All the U-type filling heights satisfy the performance required for medium-fluidity concrete.
From these results, like the test bodies 3 to 6 (Examples), the blending ratio of the paste, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio are the above (A), (D) to It is possible to produce medium-fluid concrete satisfying the performance shown in FIG. 1 by making it within the range shown in (F) and making the blending ratio of the coarse aggregate in the range shown in (B) above. It could be confirmed. Moreover, like the test body 2 (comparative example), the blending ratio of the paste, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio are indicated by the above (A), (D) to (F). Even within the above range, it was confirmed that when the mixing ratio of the coarse aggregate was outside the range shown in the above (B), medium fluidity concrete could not be produced.

<About paste: Evaluation results of test bodies 7 to 11>
The specimen 8 (comparative example) having a paste blending ratio of 297 liter / m ³ outside the range shown in the above (A) has a slump flow of 35.0 cm and satisfies the performance required for medium-fluidity concrete. However, the amount of vibration deformation and the U-type filling height are 16.3 cm and 19.0 cm, respectively, which do not satisfy the performance required for medium fluidity concrete.
In addition, the specimen 9 (comparative example) with a paste blending ratio outside the range shown in (A) above (289 liters / m ³ ) has slump flow and U-type filling heights of 40.3 cm and 29.5 cm, respectively. Yes, the performance required as medium fluidity concrete is satisfied, but the amount of vibration deformation is 17.5 cm and the performance required as medium fluidity concrete is not satisfied.
On the other hand, the specimens 7, 10, and 11 (Examples) having the blending ratio of paste within the range shown in (A) above are 306, 300, and 330 liters / m ³ , slump flow, vibration deformation amount, U type All items of filling height satisfy the performance required for medium fluidity concrete.
From these results, as in test bodies 7, 10, and 11 (Examples), the blending ratio of the coarse aggregate, the water cement ratio, the blending ratio of the high-performance AE water reducing agent, and the air content ratio are the above (B), It is possible to produce medium-fluidity concrete that satisfies the performance shown in FIG. 1 by making it within the range shown by (D) to (F) and making the blending ratio of the paste within the range shown by (A) above. It could be confirmed. Moreover, like the test bodies 8 and 9 (comparative example), the mixing | blending ratio of a coarse aggregate, a water cement ratio, the mixing | blending ratio of a high performance AE water reducing agent, and the content rate of air are said (B), (D)-( Even within the range shown in F), it was confirmed that the medium-fluidity concrete could not be produced when the blending ratio of the paste was outside the range shown in the above (A).

<About water-cement ratio: Evaluation results of specimens 12 and 13>
The specimens 12 and 13 (Examples) having a water cement ratio of 45 and 70% by weight, which are the lower limit and the upper limit of the range shown in the above (D), are slump flow, vibration deformation amount, U-type filling height. All of the items satisfy the required performance as medium fluidity concrete.
From these results, like the test bodies 12 and 13 (Examples), the blending ratio of the paste and the coarse aggregate, the blending ratio of the high-performance AE water reducing agent, and the air content ratio are the above (A), (B), It is preferable to be within the range indicated by (E) to (F) and the water cement ratio is within the range indicated by (D) above.

<Regarding the amount of air: Evaluation results of the specimens 14 and 15>
The test pieces 14 and 15 (examples) of 6 and 3% by volume, which are the upper limit value and the lower limit value of the range shown in (F) above, have slump flow, vibration deformation amount, U-type filling height. All items meet the performance requirements for medium fluidity concrete.
From these results, like the test bodies 14 and 15 (Example), the blending ratio of the paste and the coarse aggregate, the water cement ratio, and the blending ratio of the high-performance AE water reducing agent are the above (A), (B), ( D) and (E) are preferable, and the air content is preferably within the range indicated by (F).

From the above experiments, as in test bodies 3 to 7 and 10 to 15 as examples, the blending ratio of paste and coarse aggregate, water cement ratio, thickener component-containing high-performance AE water reducing agent and air content ratio It is confirmed that the medium-fluidity concrete satisfying the performance shown in FIG. 1 can be produced by setting the values in the ranges indicated by the above (A), (B), (D), (E), and (F). did it.
On the other hand, when the blending ratio of the paste is out of the range shown in the above (A) as in the test bodies 8 and 9 which are comparative examples, the blending ratio of the coarse aggregate is as described above (B In the case where it is out of the range indicated by (), it has been confirmed that the medium fluidized concrete satisfying the performance shown in FIG. 1 cannot be produced.

  Further, among the test specimens 3 to 7 and 10 to 15 that satisfy the performance required as medium-fluid concrete, the one with the smallest blending ratio of the thickener component-containing high-performance AE water reducing agent is 0.5 weight of the test specimen 13 The most common is 1.8% by weight of the specimen 12. From these results, it was confirmed that the blending ratio of the thickener component-containing high performance AE water reducing agent is preferably 0.5% by weight or more and 1.8% by weight or less.

  According to the present invention described above, a thickener component-containing high-performance AE water reducing agent is blended in place of the AE water reducing agent contained in ordinary concrete, and coarse aggregate, water, cement, and the like are blended as described above. By mixing, medium fluidity concrete can be produced.

  In addition, instead of the AE water reducing agent contained in ordinary concrete, it is only necessary to use a high-performance AE water reducing agent containing a thickener component, and the management of the material and the labor of production are almost the same as when producing ordinary concrete, It can be manufactured easily.

  Since the blending ratio of cement is almost the same as the blending ratio contained in ordinary concrete, the temperature after placing is almost the same as the temperature after placing ordinary concrete. Therefore, it can be cured in the same way as ordinary concrete, so it does not take time and the possibility of cracking does not change.

  And since addition of the cement for an additional is unnecessary, economical efficiency improves further.

  Furthermore, since the blending ratio of each material is clear, even inexperienced workers can reliably produce medium-fluid concrete.

In the above embodiment, the case where only cement is used as the hydraulic binder has been described. However, the present invention is not limited to this, and part of the cement is fly ash, blast furnace slag, limestone fine powder, respectively. You may substitute with admixtures, such as powder.
FIG. 4 illustrates an embodiment where a part of the cement is replaced with an admixture.
As shown in FIG. 4, the test bodies 16-18 which substituted some cement for the admixture were manufactured, and the result of having confirmed the slump flow of each test body 16-18, the amount of vibration deformation, and the U-type filling height. Is shown in FIG. Details of each of the test bodies 16 to 18 are as follows. In addition, the said test body 4 was used as a reference | standard for comparative examination.

<About Specimen 4>
As described above, the hydraulic binder consists only of cement, and its blending ratio is 300 kg / m ³ .

<About Specimens 16-18>
The test bodies 16-18 are the said (A), (B), (the mixing ratio of a paste and a coarse aggregate, the mixing ratio with respect to the hydraulic binder of water, the mixing ratio of a high performance AE water reducing agent, and the content rate of air. D) is adjusted to satisfy the range of (F).
Specifically, the blending ratio of the paste and coarse aggregate, the blending ratio of water with respect to the hydraulic binder, the blending ratio of the high-performance AE water reducing agent, and the air content ratio are 318 liters / m ³ or more and 326 liters / m ^{3, respectively.} Below, it adjusted to 324 liter / m < ³ >, 58%, 0.7 weight% or more and 0.9 weight% or less, and 4.5 volume%.
The test body 16 is obtained by replacing part of the cement with fly ash. Specifically, cement, and the mixing ratio of the fly ash in each ^{210kg / m 3, 90kg / m} 3, the sum of cement and fly ash, the mixing ratio of the cement is hydraulic binder contained in the specimen 4 This is an example adjusted to be the same as 300 kg / m ³ .
The test body 17 is obtained by replacing a part of the cement of the test body 4 with blast furnace slag. Specifically, cement, respectively proportion of blast furnace slag in the ^{210kg / m 3, 90kg / m} 3, the sum of cement and blast furnace slag, the same as the mixing ratio 300 kg / ^{m 3} of cement contained in the specimen 4 It is the Example adjusted so that it may become.
The test body 18 is obtained by replacing a part of the cement of the test body 4 with fine limestone powder. Specifically, cement, respectively proportion of the fine limestone fines in the ^{210kg / m 3, 90kg / m} 3, a total of powder cement and limestone fine powder, blended cement contained in the specimen 4 ratio 300 kg / ^{m 3} It is the Example adjusted so that it might become the same.

FIG. 5 is a diagram illustrating a determination result as to whether or not the slump flow, the amount of vibration deformation, the U-type filling height, and the performance of the medium fluidity concrete of the test bodies 16 to 18 according to the present embodiment are satisfied.
As shown in FIG. 5, the slump flow, the vibration deformation amount, and the U-shaped filling height of the test bodies 16 to 18 were measured. Hereinafter, the measurement results of the respective test bodies 16 to 18 will be considered with reference to FIG.

The test bodies 16-18 satisfy | fill the performance requested | required as medium fluidity concrete about all the items of slump flow, the amount of vibration deformation, and U-type filling height.
From these results, it was confirmed that even if a part of the cement was replaced with any of fly ash, blast furnace slag, and fine limestone powder, the performance required for medium fluidity concrete was satisfied. Then, the substitution rate was calculated by (90 kg / m ³ ÷ 300 kg / m ³ ) × 100 = 30, and it was confirmed that the substitution ratio may be 30% of the hydraulic binder.

  By the above experiment, like the test bodies 16-18, the mixing ratio of paste and coarse aggregate, the mixing ratio of water to the hydraulic binder, the mixing ratio of the thickener component-containing high-performance AE water reducing agent, the inclusion of air The ratio shown in FIG. 1 is satisfied even if the ratio is within the range indicated by the above (A), (B), (D), (E), (F) and a part of the cement is replaced with an admixture. It was confirmed that fluid concrete could be manufactured.

  According to the present invention described above, the amount of cement can be reduced by substituting a part of the cement with an inexpensive admixture, thereby improving the economic efficiency.

  In this embodiment, the blending ratio of water contained in the paste with respect to the hydraulic binder is 45% by weight or more and 70% by weight or less of the range shown in the above (D), but is not limited to this range. In addition, depending on the blending ratio of each member to be blended, even those manufactured outside this range may satisfy the performance of the medium fluidity concrete.

  In the present embodiment, the blending ratio of the thickener component-containing high-performance AE water reducing agent is 0.5% by weight or more and 1.8% by weight or less of the range shown in (E) above, but is limited to this range. However, depending on the blending ratio of each member to be blended, even those manufactured outside this range may satisfy the performance of the medium fluidity concrete.

  In addition, in this embodiment, although the content rate of air was 3 volume% or more and 6 volume% or less of the range shown by said (F), it is not limited to this range, The mixing | blending of each member mix | blended Depending on the proportion, even those manufactured outside this range may meet the performance of medium fluidity concrete.

  In addition, although this embodiment demonstrated the case where the thickener component containing high performance AE water reducing agent by which a high performance AE water reducing agent and a thickener were already mixed was used, it is not limited to this. When producing medium fluidity concrete, a high-performance AE water reducing agent and a thickening agent may be mixed with other materials, respectively.

Claims (6)

A mixture of water and a hydraulic binder, and a paste of 300 liters / m ³ or more and 330 liters / m ³ or less;
Coarse aggregate of 280 liters / m ³ or more and 360 liters / m ³ or less,
A high-performance AE water reducing agent containing a thickener component ,
The amount of increase in the slump flow after vibration is greater than the slump flow before vibration when the U-type filling height (when there is no obstacle) is 28.5 cm or more and the slump flow in the slump flow test is vibrated. 7 cm or more and 13 cm or less,
A medium-fluidity concrete , wherein a blending ratio of the thickener component-containing high-performance AE water reducing agent to the hydraulic binder is 0.5 wt% or more and 1.8 wt% or less .   The medium-fluidity concrete according to claim 1, wherein a mixing ratio of the water to the hydraulic binder is 45 wt% or more and 70 wt% or less. The medium-fluidized concrete according to claim 1 or 2 , wherein the medium-fluidized concrete after production contains 3% by volume or more and 6% by volume or less of air. The medium fluidity concrete according to any one of claims 1 to 3 , wherein the hydraulic binder is cement. The medium fluidity concrete according to any one of claims 1 to 3 , wherein the hydraulic binder includes cement and an admixture. The admixtures, fly ash, blast furnace slag, fluidity concrete in the claim 5, characterized in that either the end of limestone fines.

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