JP2602438B2 - Manufacturing method of ultra-high fluidity concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing ultra-high fluidity concrete.

2. Description of the Related Art Conventional fluidized concrete maintains its fluidity without increasing the unit water amount or using a water reducing agent or a fluidizing agent to increase the unit water amount.

Problems to be Solved by the Invention However, the above-mentioned conventional fluidized concrete has a large amount of drying shrinkage and breathing due to an increase in a unit water amount and an amount of cement, and is not only easily cracked, but also has a water reducing agent or a fluidizing agent. The slump loss was large and the quality control was difficult for the high slump fluidized concrete used.

Also, when slumps are large to 22 to 24 cm and cast into complex formwork or high-density reinforcement, there are conflicting properties such as separation of materials and easy occurrence of junkers and sand skin, There were problems such as difficulty in quality control and construction management.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to compact a concrete member having a complicated shape, a member having a high bar arrangement density, or a vibrator or the like at a corner portion or the like. It is an object of the present invention to provide a method for producing ultra-highly fluidized concrete which has very good fluidity and filling properties with uniform quality even in places where work is difficult and without compaction work, and does not cause material separation.

B. SUMMARY OF THE INVENTION Means for solving the problems The super-high fluidity concrete produced by the method of the present invention is obtained by adding a separation reducing agent, a defoaming agent, and a water reducing agent to a base concrete composed of cement, aggregate, water and the like. Alternatively, it is constituted by adding a fluidizing agent, and in addition, admixtures such as fly ash, silica fume and mineral clay can be used depending on the application.

As the type of cement, any of portland cement, blast furnace cement, silica cement, fly ash cement and the like may be used.

Aggregate is not limited to sand, gravel, crushed stone, etc.
Any one may be used as long as it passes the S criteria.

As the separation reducing agent, non-ionic water-soluble cellulose, ethylhydroxyethylcellulose, sebiolite-based mineral and polyethylene oxide are used alone or as a mixture. %, Sebiolite-based mineral is 0.1-5.0% by weight based on cement, and polyethylene oxide is 0.01-3.0% based on cement.
% By weight.

As antifoaming agent, non-ionic SN deformer 14HP is used, its blending ratio is 0.01 ~ 1.0% by weight with respect to cement, and the air entrainment amount of concrete can be adjusted between 0.1 ~ 10% .

Examples of the water reducing agent or the fluidizing agent include commonly used polyol complexes, lignin sulfonic acid compounds, oxycarboxylates, highly condensed triazine compounds, melamine sulfonic acid compounds, and the like. However, high-condensation products of naphthalenesulfonic acid salt are ethyl hydroxyethyl cellulose and SN
Fluidity and fillability when mixed with Deformer 14HP cannot be ensured.

As for the properties of the concrete at the time of kneading according to the above-mentioned compounding degree, the slump is 20 to 27 cm, the slump flow is 45 to 80 cm, and the filling property is 35 to 0, and no material separation occurs.

In addition, ultra-high flow performance can be maintained for about 90 minutes after kneading,
The properties before and after pumping do not change.

Furthermore, the strength performance does not change even when compared with the base concrete before adding the above-mentioned additives.

Next, various methods for producing the above-mentioned ultra-high fluidity concrete will be described.

(1) Cement, aggregate, separation reducing agent (ethyl hydroxyethyl cellulose, sebiolite, polyethylene oxide) and antifoaming agent (polyester type antifoaming agent) A certain SN deformer (14HP) is charged, and the mixture is sufficiently mixed according to the performance of the mixer. Thereafter, water and a water reducing agent or a fluidizing agent are added and kneaded.

(2) After arriving at the site of the concrete of the standard mix discharged into the mixer truck, a separation reducing agent, an antifoaming agent, a water reducing agent or a fluidizing agent are added and kneaded with the mixer truck.

(3) Add a part of the total water-reducing agent in advance and reduce the slump to 20.
After arriving at the site where the concrete is adjusted by a plant mixer within ~ 25 cm, the separation reducing agent, the defoaming agent and the remaining water reducing agent or fluidizing agent are added and kneaded with a mixer truck.

Example The composition shown in Table 1 was used as the base concrete.

0.3% by weight of ethyl hydroxyethyl cellulose to cement and 14HP of nonionic SN deformer to cement
0.1% by weight, NL-4000 as a water reducing agent for cement
Ultra-high fluidity concrete was obtained by adding 3.0% by weight each.

The properties of the ultra-high fluidity concrete are as shown in Table 2.

Among the properties in Table 2 above, slump values were obtained based on the slump test method of JIS A1101.

Also, the value of the slump flow is, as shown in FIG.
First, a slump cone 2 for a slump test was placed on an iron plate 1.
After the super-fluidized concrete 3 is filled into the upper end thereof, the slump cone 2 is gently pulled up vertically, and at this time, the super-fluidized concrete 3 spreads over the iron plate 1 to have an expanded diameter. The maximum value and two points in the direction perpendicular to the maximum value are measured, and the average value is defined as the slump flow value.

Further, as shown in FIG. 2 (A), in the first chamber 6 on one side of the box 5 partitioned by the partition plate 4, a high AC mobilized concrete 7 having a height of 40 cm from the bottom plate 8 is provided. After that, the partition plate 4 is pulled up and stopped at a height of 12 cm from the bottom plate 8 as shown in FIG.
Flows into the second chamber 9 from the first chamber 9 when the second chamber 9 is filled.
The difference H between the height of the super-high fluidized concrete 7 in the chamber and the second chamber is defined as the value of the filling property.

Furthermore, regarding the strength characteristics of the ultra-high fluidity concrete, as shown in FIG.
A base concrete 11 for comparison is poured into the concrete 10 and a super-fluidized concrete 13 of the present invention is poured into a similar columnar full-scale structure 12 as shown in FIG. 3 (B). I do.

In the case of the base concrete 11 shown in FIG. 3 (A), the casting was performed by hitting one layer by 50 cm and compacting with three high frequency rod vibrators for 20 seconds for each layer.

In the case of the super-fluidized concrete 13 shown in FIG. 3 (B), the concrete was continuously poured without compaction work.

As a result, as shown in FIG. 4, the strength is almost the same at any height, and the ultra-high fluidity concrete of the present invention does not show a decrease in strength as compared with the base concrete. understood.

Applications of the ultra-high fluidity concrete of the present invention include RC mid-high rise houses, PC girders, hollow slabs, etc., which are economically designed structures with a thin member thickness and high reinforcing bar density, walls with hollow parts, and stamped walls. Pillows with high pile height, continuous walls, underwater structures, structures that are difficult to compact such as RT lining, and fiber spacing that can reduce the cover thickness without fear of rusting in place of rebar. There are structures using narrow long fibers.

C. Advantageous Effects of the Invention (1) Since compaction work using a vibrator or the like becomes unnecessary, the construction is rationalized and labor-saving, and the construction cost is reduced.

(2) Since there is no material separation, high strength can be maintained without occurrence of jumper or sand.

(3) Since the fluidity and the filling property are good, it is easy to fill the inside of a mold having a complicated shape or a dense arrangement of reinforcing bars.

(4) The slump has little change with time, and quality control is easy.

(5) Defects due to human error at the site, deterioration in quality and variations due to traffic conditions are reduced, and concrete with high durability and reliability can be constructed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a slump flow test, and FIG. 2 (A)
(B) is an explanatory view of a filling test, FIGS. 3 (A) and (B) are explanatory views of a strength test, and FIG. 4 is a graph showing a comparison of a change in strength depending on the height of a columnar structure. 1 ... iron plate, 2 ... slump cone, 3 ... ultra-high fluidity concrete, 4 ... partition plate, 5 ... box, 6 ...
1st room, 7 ... super fluidized concrete, 8 ... bottom plate,
9: 2nd room, 10: Full-scale columnar structure, 11: Base concrete, 12: Full-scale columnar structure, 13: Ultra-high fluidity concrete.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location // C04B 103: 32 103: 44 103: 50

Claims (3)

(57) [Claims] 1. A cement for a ready-mix plant, comprising:
Aggregate, the separation reducing agent consisting of ethyl hydroxyethyl cellulose, sebiolite or polyethylene oxide, and a polyether type defoaming agent are charged and mixed well according to the performance of the mixer, and then water and a polyol complex, Lignin sulfonic acid compound, oxycarboxylate,
A method for producing an ultra-highly fluidized concrete, comprising adding a water reducing agent or a superplasticizer comprising a highly condensed triazine-based compound, a melamine sulfonate-based compound or the like and kneading the mixture. 2. After arriving at the site of the concrete of standard mix discharged into a mixer truck, a separation reducing agent composed of ethyl hydroxyethyl cellulose, sebiolite or polyethylene oxide, a polyether-type defoaming agent, a polyol composite, A super-high fluidity comprising adding a water reducing agent or a fluidizing agent comprising a lignin sulfonic acid compound, an oxycarboxylate, a highly condensed triazine-based compound, a melamine sulfonate-based compound, and the like, and kneading with a mixer truck. Method of producing reinforced concrete. 3. A method of slumping in which a total of a water reducing agent or a part of a fluidizing agent such as a polyol complex, a lignin sulfonic acid compound, an oxycarboxylate, a highly condensed triazine compound or a melamine sulfonate compound is added in advance. Between 20 and 25 cm on the plant, upon arrival at the concrete prepared by the mixer, the separation reducing agent consisting of ethyl hydroxyethyl cellulose or sebiolite or polyethylene oxide, the polyether type defoaming agent and the remaining water reducing agent or fluidization And kneading the mixture with a mixer truck.