JPS59227752A - Concrete admixing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a concrete admixture that improves the surface appearance and freeze-thaw resistance of concrete products such as concrete blocks, and improves workability.

Advances in concrete technology have led to pressure forming of hard wire or cemented concrete with mechanical external vibration compaction, but this immediate demolding (B
Concrete products that can be removed from the surface will suffer from poor surface aesthetics, formability, and
Variations are likely to occur in qualities such as dimensional stability, freeze-thaw tIs resistance, workability, and compressive strength. Therefore, it is desirable to have an easily obtainable admixture for products with excellent properties! It is.

For example, adding a foaming 7-ionic surfactant and a non-ionic surfactant such as Vc flukylbenzenesulfonate (Autumn Mixed Concrete) allows air to flow and improves the workability of concrete. Also, foaming 7-ion surfactants often have improved freeze-thaw resistance. However, simply adding a foaming surfactant to hard-mixed concrete under vibration has the disadvantage that workability and freeze-thaw resistance cannot be satisfied. Furthermore, it has been found that there is a tendency for compressive strength to decrease and dimensional stability to be compromised. Therefore, for hard-mixed concrete and super-hard-mixed concrete, it is not possible to entrain air, which is excellent for improving freeze-thaw resistance, by mixing only a foaming surfactant.

The purpose of the present invention is to improve the formability and dimensional stability of hard mixed concrete and super hard mixed concrete, and to obtain concrete with excellent freeze-thaw resistance, compressive strength, and surface beauty. The objective is to provide an admixture that can be used as an admixture.

The present inventors have conducted intensive research on improving the above-mentioned qualities of hard-mixed concrete and super-hard-mixed concrete.

To mix air bubbles into concrete, there is a method of adding a foaming surfactant to the concrete mixing water, and a method of foaming the foaming surfactant with an appropriate foaming machine, which is necessary when mixing concrete. There is a method of mixing in a certain amount of foam, but a method that is generally easy to apply is to add a foaming surfactant to forest water and mix the required amount of foam into the concrete edge mix. This method is simple and easy to adopt.

However, as mentioned above, it was found that it was difficult to impart moldability, surface aesthetics, and dimensional retention just by adding a foaming surfactant, so we investigated ways to improve these physical properties. In order to not reduce the compressive strength without increasing air bubbles and to improve the surface appearance, it is necessary to improve the dispersion and filling properties of cement milk and mortar, and to improve the freeze-thaw resistance. It is necessary to stably maintain the fine entrained air bubbles that are extremely effective against mechanical vibrations and pressurized conditions. Ta.

Dextrin, dextran, natural water-soluble gum, It has been found that soluble starch is a substance that does not impair the workability of concrete (it has been found that it can be effective).

Therefore, by making various combinations of these substances, adding them when mixing concrete with carbide, and performing pressure forming under mechanical vibration, we were able to successfully obtain concrete products of extremely desirable quality. , we have completed the present invention.

That is, the present invention contains a mixture of 10 to 90% by weight of an anionic or nonionic surfactant and 90 to 10% by weight of nrubitol, dextrin, dextran, oligosaccharides, soluble starches, or natural water-soluble gums. This relates to concrete admixtures.

Nrubitol and oligosaccharides used in the present invention have the effect of increasing the friction-reducing property and water-reducing property under pressure, increasing the number of adhesion points between cement particles and between fine aggregate and coarse aggregate, To improve filling properties by strongly interlocking fine aggregate and coarse aggregate. Furthermore, it is effective in making cement milk and mortar appear on the surface more easily, stabilizing entrained air bubbles in the cement milk, and finishing the surface neatly and uniformly.

Also dextrin, dextran, natural water-soluble gums,
Because it does not have excessive dispersibility for cement particles, it is difficult to apply Haramachi plasticity or plasticity to the turbidity of fine particles in water, which is a characteristic of this type of polymeric material. This can have a very favorable effect on the formability and dimensional stability of concrete.

Therefore, even if a 7-ionic or non-ionic surfactant is mixed alone, it may be somewhat effective.
By blending the rice ingredients in a specific proportion as described above,
It was found that the quality required for a ready-to-deblock product could be sufficiently imparted, and the present invention was successful.

As the anionic or nonionic surfactant that is the first component of the present invention, those generally used as air entraining agents or foaming agents can be applied, but as the 7-ionic surfactant, flukylbenzenesulfone acid salts, alkyl sulfates, alkyl polyoxyethylene glycol sulfates,
Furkylphenol polyoxyethylene glycol 4
Examples of 7 include acid salts, flucansulfonates, α-olefin sulfonates, rosinates, salts of rosin derivatives, alkylsulfoconophosphates, etc. Nonionic surfactants include polyoxyethylene furkyl ether. , polyoxyethylene furkylphenyl ether, furkylamide, and the like. The general formula of typical % is shown below.

R, -c) -S03M (R1 = 010 to C14 furkyl group, M = furanyl metal, ammonium or flukanolamine) R2050
, M (R2 = c8 to C18 saturated or unsaturated hydrocarbon group,
M=same as above) R30(C, H2C; R2snS03M(R3=c,
. ~C18 saturated or unsaturated hydrocarbon group, M=same as above) R4C3)-0(OH2CjH2.803M(R4=
08-C12 furkyl group, M=same as above) R5-CH2
So, M (Furkyl group of R5-07 to C23, M = same as above) R6-
GH=OH(OH2)nS03MR6-OH-OH(O
H2) nS03MOH (R6 = 04-C22 furkyl group, n = 1-2
.

M = same as above) R, 00G and R2 RO00-G-5o6M (R, = alkyl group of c6 to CI2, M = same as above) R8
0 (CH2CH2snH ("8"'10"'-018 saturated or unsaturated hydrocarbon group, n = 5-50) (R9""C6"-C12 furkyl group, rn =
5-50) Also, the second component of the present invention is nrubitol,
These include oligosaccharides, dextrins, soluble starches, natural water-soluble gums, dextran, and xanthan gums.

Further, when it is made into an aqueous solution, urea as a viscosity reducing agent and inorganic salts effective in reducing viscosity can be added in small amounts.

Hereinafter, the present invention will be explained in further detail with reference to Examples.

Example 1 Concrete was made into a scaffold under the following mixing conditions. The materials used are m (ky) per cubic meter.

Ordinary Portland cement (Chichibu cement) 270k
g, forest water 95kl, river sand 998kp, natural river gravel 99g
8kJI, W10=35%, VA-50%.

Kneading water Km-IKi admixture i 0.108 ky (
20% liquid 0.54! In addition, strong! Knead for 3 minutes using an Il stirring mixer. On the other hand, the formulation of plain concrete without adding admixtures is as follows.

(Chichibu Cement) 270 kg, kneaded water LOOkg.

River sand 1017, y, natural river gravel 1018 kPs y
c=37%, S/a=50%.

Cement ratio: 5.17 Sand (monthly production) ratio: Q: 2.56
2.0% coarse aggregate (Hidaka usage ratio 1 @ 2.56 Gravel water absorption rate 1.1% coarse aggregate maximum dimension 20m Gravel moisture content 1
．． 1% This was made into 5900-4000R, P, M,
(65-67h) frequency, amplitude 1.5-1.5
m, vibration acceleration 10.2-12, filling for 3 seconds at G,
Acid molding was carried out using a press pressure of 1.0 kg/2 kg for 5 seconds. The amount of concrete to be filled is approximately 45.
It is 5 kg.

Immediately after demolding, the mold is removed, the dimensions are measured, and steam curing is performed. The steam curing conditions were as follows: 2 hours of preheating time, 2 hours of temperature rise from 20℃ to 60℃, and 1 hour temperature rise to 60℃.
Leave it for a while and then let it cool naturally. After steam curing, the surface part (
30om x 451)
The dimensional retention was determined based on the percentage of expansion and contraction relative to the original size.

We also looked at the surface aesthetics from the surface finish and smoothness.

Concrete specimens for measuring freeze-thaw resistance, degree of air inclusion, and compressive strength were cut out of 10 parts x 1 x 10011 x 40 parts using a diamond cutter. Compression strength testing was carried out in a conventional manner on a 10 x 10 x 20 oa square column that had been slowly submerged in water for 28 days. The degree of bubble inclusion is determined by g1.
By the mirror, the flesh [by 5 m x 5 ('tjt
= 25- Measure the number, diameter, etc. of bubbles present in 1
It was measured as the number of bubbles per 3 saws.

The results are shown in Table-2. As is clear from Table 2, the present invention was found to be more effective than the control plain concrete and conventional foaming agents.

Table 1 Table 1 (Continued) Example 2 The concrete mixing conditions, materials, and block forming conditions were the same as in Example 1. The concrete mix is 240 kg of ordinary Portland cement, 116 kg of fresh water, and 10 kg of river sand.
11 kjl, river gravel 1004 kg per cubic meter, S/A = 51%, water-cement ratio 0.4
It is 85.

The compressive strength test piece has a diameter of 10cIM and a height of 20cm.
The cylindrical core was removed and cured in air for 14 days, without steam curing at all.

Dimensional retention, surface aesthetics, and freeze-thaw resistance were measured in accordance with Example 1 on test pieces that had been cured in air for 14 days. The results are shown in Table-6.

Claims (1)

[Claims] 17 10 to 90% by weight of anionic or nonionic surfactant, sorbitol, dextrin, dextran,
Oligosaccharides, soluble starches or natural water-soluble gums 90~
Concrete admixture containing a mixture of 10%. 2 Z ionic surfactant is furkylbenzene sulfonate, alkyl sulfate, furkyl polyoxyethylene glycol sulfate, 7/L/kylphenol polyoxyethylene glycol sulfate, 7N cansulfonate, α-
Olefin sulfonates, rosinates, rosin evaluation conductors (
1 selected from 1)m, 7)/killsulfokonophosphate
The admixture according to claim 1, which is one or more types. 6. The admixture according to claim 1, wherein the nonionic sacrificial agent is one or more selected from polyoxyethylene alkyl ether, polyoxyethylene furkylphenyl ether, and furkylamide.