JPH11314956A - Mixing method of antiwashout concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which the fluidity of antiwashout concrete can be improved without increasing its unit water content and unit cement content and also no reduction in packing property of the concrete is caused even when its unit water content and unit cement content are decreased. SOLUTION: Highly-fluidizing antiwashout concrete 10 mixed by this method, comprises a binder 2 contg. cement, water 1, fine aggregate 3, coarse aggregate 4, etc., and is used in the execution of underwater construction work of a concrete structure. In this method, with the mix proportion of antiwashout concrete 20 having a prescribed fluidity, as a reference, the unit water content and unit cement content are decreased from the reference values respectively and the total decrement is compensated with a powder 6 such as fine limestone powder and fly ash, to maintain the content of paste formed by mixing the powder 6, water 1 and the binder 2 together at a constant level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of blending non-separable underwater concrete used, for example, when constructing underwater mass concrete structures or densely reinforced underwater reinforcement structures.

[0002]

2. Description of the Related Art In a conventional method of blending non-separable concrete underwater, as shown in FIG. 4, for example, when the unit water amount is reduced, the paste amount (water 1 and binder) is reduced in accordance with the unit water amount decrease. 2) decreased, and fine aggregate 3 and coarse aggregate 4 increased accordingly.

[0003]

However, in the conventional method of blending underwater non-separable concrete, as described above,
When the unit water amount (or the unit cement amount) is decreased, the paste amount is decreased, and the amount of the fine aggregate 3 and the coarse aggregate 4 is increased, so that the fluidity of the concrete is reduced. In the case where was subjected to casting, the filling property between the reinforcing bars was sometimes reduced. In addition, in the conventional method of mixing water-immiscible concrete, the unit water amount and the unit cement amount are increased to reduce the water-cement ratio and improve the fluidity of the concrete. With the increase in the amount of heat, the calorific value due to hydration increases, which may cause, for example, cracks and other problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to improve the fluidity without increasing the unit water amount and the unit cement amount. It is an object of the present invention to provide a method for blending in-water inseparable concrete in which the filling property does not decrease even when the amount is reduced.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to claim 1 comprises a binder such as cement, water,
A method for blending underwater non-separable concrete comprising aggregates and the like and used in underwater construction of a concrete structure, the unit water content and unit cement based on the blending of the underwater non-separable concrete having a predetermined fluidity. The amount is reduced, and the reduced amount is supplemented with a powder such as limestone fine powder or fly ash to maintain a constant paste amount of the powder, the water and the binder.

According to the first aspect of the present invention, the unit water amount and the unit cement amount are reduced based on the composition of the in-water inseparable concrete having a predetermined fluidity, and the reduced amount is reduced to limestone fine powder or By supplementing with powder such as fly ash, etc., the amount of paste combining powder, water and binder was kept constant, so that the fluidity of underwater non-separable concrete was reduced by reducing the amount of water and unit cement. Therefore, the fluidity is maintained at the predetermined fluidity. That is, the unit water amount and the unit cement amount required to achieve the predetermined fluidity can be reduced as compared with the conventional mixing method in which powder is not mixed. Thereby, the calorific value due to hydration can be reduced, and the strength ratio in water and air can be increased.

A second aspect of the present invention is a method for blending underwater non-separable concrete, which comprises a binder such as cement, water, aggregate and the like, and is used for underwater construction of a concrete structure. The method is characterized in that the unit water amount is reduced based on the composition of the in-water non-separable concrete having the following, and a high-performance AE water reducing agent is mixed in accordance with the reduced amount.

According to the second aspect of the present invention, the unit water amount is reduced based on the composition of the underwater non-separable concrete having a predetermined fluidity, and a high-performance AE water reducing agent is prepared according to the reduced amount. Because of the mixing, the fluidity of the underwater non-separable concrete is maintained at the predetermined fluidity even when the unit water amount is reduced. That is, the unit water amount required to achieve the predetermined fluidity can be reduced as compared with the conventional mixing method in which the high-performance AE water reducing agent is not mixed. Thereby, the calorific value due to hydration can be reduced, and the strength ratio in water and air can be increased. In other words, even if the unit water amount and the unit cement amount are not increased, the high performance A
By mixing the E water reducing agent, the fluidity of the underwater non-separable concrete can be improved.

Specific examples of high-performance AE water reducing agents include polycarboxylic acid ether-based composites, polycarboxylic acid ether-based crosslinked polymer composites, modified lignin-
Examples thereof include a composite of an alkyl allyl sulfonic acid and an active-persisting polymer, a composite of a polycarboxylic acid, and a composite of a polyalkyl sulfonic acid.

According to a third aspect of the present invention, there is provided a method for compounding a non-separable underwater concrete which comprises a binder such as cement, water, fine aggregate, coarse aggregate and the like and is used in underwater construction of a concrete structure. Based on the composition of the water-insoluble separable concrete having predetermined fluidity and filling properties, a powder such as limestone fine powder or fly ash, a paste amount obtained by combining the water and the binder, and an amount of the fine aggregate. And the amount of the coarse aggregate is reduced by the increase.

According to the third aspect of the present invention, based on the composition of underwater inseparable concrete having predetermined fluidity and filling properties, powder such as limestone fine powder or fly ash, water and binder The amount of fine aggregate and the amount of paste combined with are increased, and the amount of coarse aggregate is reduced by the increased amount, so that the fluidity of the non-separable concrete in water is improved as compared with the predetermined fluidity. Therefore, for example, even in a structure with densely arranged reinforcing bars or a complicated shape, concrete can be filled to the corners of the formwork without causing material separation.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing a method of blending a non-separable underwater concrete according to the present invention.

In the method for mixing underwater non-separable concrete according to the present invention, as shown in FIG. 1, the underwater non-separable concrete composed of water 1, binder 2, fine aggregate 3, coarse aggregate 4 and air 5 is provided. Highly fluid underwater non-separable concrete 1 having desired fluidity based on the composition and fluidity of
0 is blended. The high fluidity water-unseparable concrete 10 is used, for example, in underwater construction of a concrete structure, and as shown in FIG. 1, water 1, binder 2, powder 6, fine aggregate 3, coarse aggregate 4, and It is composed of air 5 and the like.

The binder 2 contains, in addition to cement, admixtures such as an inseparable admixture in water and a high-performance AE water reducer. Examples of the high-performance AE water reducing agent include a polycarboxylic acid ether-based complex, a complex of a polycarboxylic acid ether and a crosslinked polymer, a complex of modified lignin / alkylallylsulfonic acid and an active-persisting polymer, and a polycarboxylic acid-based Or a polyalkylsulfonic acid-based composite. The powder 6 is, for example, fine limestone powder or fly ash.

Next, high fluidity water-inseparable concrete 1
The method of compounding 0 will be specifically described with reference to FIG.

For example, when compounding the highly fluid underwater non-separable concrete 10 having a desired fluidity, as shown in FIG. Then, the unit water amount and the unit cement amount are reduced, and the reduced amount is supplemented by the powder 6, so that the powder 6, the water 1 and the binder 2 are combined so as to keep the combined paste amount constant. Since the amount of the paste and the amount of aggregate of the highly fluid underwater non-separable concrete 10 thus mixed are the same as the underwater non-separable concrete 20, the fluidity of the underwater non-separable concrete 20 is also high. That is, it substantially matches the desired fluidity. At this time, the high fluidity water-unseparable concrete 10 has a smaller amount of water and unit cement than the underwater non-separable concrete 20, so that the calorific value due to hydration is reduced, and one index of the water-unseparable performance. Is increased.

In addition, for example, when compounding the highly fluid underwater non-separable concrete 10 having fluidity higher than a predetermined fluidity, the blending of the underwater non-separable concrete 20 having predetermined fluidity is used as a reference. Then, the amount of the paste combining the powder 6, the water 1 and the binder 2 and the amount of the fine aggregate 3 are increased, and the amount of the coarse aggregate 4 is reduced by the increased amount. Then, since the amount of the coarse aggregate 4 of the high fluidity water-immiscible concrete 10 is smaller than that of the underwater immiscible concrete 20, the fluidity and the filling property are improved. Therefore, for example, even for a structure with a densely arranged reinforcing bar or a complicated shape, concrete can be filled up to the corner of the formwork without causing material separation. Here, when the paste amount is increased, if the paste amount is increased only by the powder 6 without increasing the amounts of the water 1 and the binder 2, the increase in the calorific value due to hydration is suppressed. It is also possible.

Further, if a high-performance AE water reducing agent is mixed into the high-flowable water-impartable concrete 10 mixed as described above, the flowability of the high-flowable water-impossible concrete 10 can be further improved. . In addition, by mixing the high-performance AE water reducing agent, the unit water amount of the high-fluid water non-separable concrete 10 having a predetermined fluidity can be further reduced.

Next, the high fluidity water-inseparable concrete 1
The difference between the fluidity and the filling property of the underwater non-separable concrete and the conventional non-separable concrete will be described with reference to FIGS.

FIGS. 2 and 3 show the results of tests for confirming the fluidity and filling property of concrete using a reinforced cage.
FIG. 2 shows the case of the high fluidity water-inseparable concrete, and FIG. 3 shows the case of conventional underwater non-separable concrete.

In FIG. 2 and FIG. 3, 8 casting pipes, 9, 1
Reference numeral 1 denotes a reinforcing bar (rebar basket), and the dotted line indicates the flow gradient immediately after the concrete is poured, and the solid line indicates the flow gradient after the concrete has stopped flowing. In addition, the conventional underwater non-separable concrete has a slump flow of 55 cm. On the other hand, the high fluidity water-inseparable concrete 10 has a unit water amount and a unit cement amount less than the conventional underwater non-separable concrete. The amount of the paste and the amount of the fine aggregate 3 are increased while the ratio between the amount of the paste and the amount of the fine aggregate is kept constant, and the amount of the decrease is replaced with the powder 6 of the limestone fine powder. The amount of coarse aggregate 4 is reduced and a predetermined amount of high performance AE
What mixed a water reducing agent (slump flow 59 cm) is used.

Immediately after the completion of the casting of the concrete, as shown in FIGS. 2 and 3, the surface of the high-flowable water-immiscible concrete 10 and the surface of the conventional water-immiscible concrete are:
In both cases, the portion up to the reinforcing bar 9 close to the casting pipe 8 is in a state of being raised as compared with other portions. When the flow of the concrete stops after a predetermined time from this state, in the case of the conventional underwater non-separable concrete, FIG.
As shown in (1), a phenomenon occurs in which the coarse aggregate 4 meshes at the position of the reinforcing bar 9 and only the mortar flows. In addition, the height of the concrete surface does not become constant, but becomes lower as the distance from the position below the casting pipe 8 increases. On the other hand, in the case of the non-separable concrete 10 having high fluidity in water, as shown in FIG. 2, the concrete is filled up to the corners of the formwork without separating the concrete at the reinforcing bars 9 and 11, and the height of the concrete surface is increased. Has a substantially constant height.

[0024]

According to the first aspect of the present invention, the unit water amount and the unit cement amount are reduced based on the composition of the in-water inseparable concrete having a predetermined fluidity, and the reduced amount is reduced to limestone fine powder. Or, by supplementing with powder such as fly ash, the amount of paste combining powder, water and binder was kept constant, so the fluidity of underwater non-separable concrete decreased in unit water amount and unit cement amount Even so, the predetermined fluidity is maintained. That is, the unit water amount and the unit cement amount required to achieve the predetermined fluidity can be reduced as compared with the conventional mixing method in which powder is not mixed. Thereby, the calorific value due to hydration can be reduced, and the strength ratio in water and air can be increased.

According to the second aspect of the present invention, the unit water amount is reduced based on the composition of the underwater non-separable concrete having a predetermined fluidity, and the high-performance AE is reduced according to the reduced amount.
Since the water reducing agent is mixed, the fluidity of the underwater non-separable concrete is maintained at the predetermined fluidity even when the unit water amount is reduced. That is, the unit water amount required to achieve the predetermined fluidity can be reduced as compared with the conventional mixing method in which the high-performance AE water reducing agent is not mixed. Thereby, the calorific value due to hydration can be reduced, and the strength ratio in water and air can be increased. In other words, even if the unit water amount and the unit cement amount are not increased, the high performance AE
By mixing the water reducing agent, the fluidity of the underwater non-separable concrete can be improved.

According to the third aspect of the present invention, powder such as limestone fine powder or fly ash, water and a binder are mixed based on the composition of the water-insoluble separable concrete having predetermined fluidity and filling properties. Since the combined paste amount and fine aggregate amount are increased and the coarse aggregate amount is decreased by the increased amount, the fluidity of the water-inseparable concrete is improved as compared with the predetermined fluidity. Therefore, for example, even in a structure with densely arranged reinforcing bars or a complicated shape, concrete can be filled to the corners of the formwork without causing material separation.

[Brief description of the drawings]

FIG. 1 is a view showing a method of blending a high fluidity water-inseparable concrete according to the present invention.

FIG. 2 is a view showing the results of a test for confirming the fluidity and filling property of highly fluid non-separable concrete in water using a reinforcing cage.

FIG. 3 is a diagram showing the results of a test for confirming the fluidity and filling property of a conventional underwater non-separable concrete using a reinforced cage.

FIG. 4 is a diagram showing a conventional method of mixing underwater non-separable concrete.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water 2 Binder 3 Fine aggregate 4 Coarse aggregate 5 Air 6 Powder 8 Casting pipe 9, 11 Steel basket 10 High fluidity inseparable concrete 20 Underwater inseparable concrete

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Tadashi Watanabe 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Corporation

Claims (3)

[Claims] 1. A method for blending underwater non-separable concrete comprising a binder such as cement, water, aggregate and the like and used in underwater construction of a concrete structure, comprising: Based on the composition of the concrete, the unit water amount and the unit cement amount were reduced, and the reduced amount was supplemented with a powder such as limestone fine powder or fly ash to combine the powder, the water and the binder. A method for mixing underwater non-separable concrete, characterized in that the paste amount is kept constant. 2. A method for blending underwater non-separable concrete comprising a binder such as cement, water, aggregate and the like and used in underwater construction of a concrete structure, comprising: A method for mixing water-inseparable concrete, comprising reducing a unit water amount based on the mixing ratio of the concrete and mixing a high-performance AE water reducing agent in accordance with the reduced amount. 3. A method for blending underwater non-separable concrete comprising cement-containing binder, water, fine aggregate, coarse aggregate, and the like, which is used in underwater construction of a concrete structure. On the basis of the composition of underwater non-separable concrete having a filling property, the amount of paste such as limestone fine powder or fly ash, the water and the binder, and the amount of fine aggregate are increased, and the increase A method for blending non-separable concrete in water, characterized in that the amount of coarse aggregate is reduced by the amount.