JPS63129049A - Ae water reducing 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] [Field of Industrial Application] The present invention relates to an AE water reducing agent used in the production of concrete, in particular, ■ligninsulfonate, ■formalin condensate of naphthalenesulfonic acid, or naphthalenesulfonic acid and ligninsulfone. This relates to an AE water reducing agent containing a formalin cocondensate with an acid (referred to as a naphthalene sulfonic acid dispersant), (1) thiocyanate, and (2) triethanolamine in specific proportions.

[Conventional technology]

Conventional accelerator-type AE water reducers can be used as an alternative to early-strength cement by adding them to ordinary cement, or can be added to early-strengthening cement in special construction projects.

Furthermore, it has been used for the purpose of increasing durability.

However, existing AE water reducers use cac as an accelerator.
Because it contains chlorides such as Q and Z, there is a problem of corrosion and rusting of reinforcing bars in concrete.

Its use in prestressed concrete structures and reinforced concrete structures has been restricted.

In addition to CaCO2, catalysts for cement hydration reactions include inorganic ones such as nitrates, nitrites, thiosulfates, and thiocyanates, and organic ones such as amines such as triethanolamine, formic acid, and acetic acid.

Salts such as acrylic acid are known. However, all of them have problems in terms of price, and none of them are in practical use.Some of them are water reducers and AE water reducers with a small amount of 1+ added to them to compensate for the setting retardation of the water reducers. It was only used in

Recently, techniques such as the combination of thiocyanate and nitrite and the combination of thiocyanate and thiosulfate have been reported, but none of them are completely satisfactory.

[Problem that the invention seeks to solve]

AE water-reducing agents are usually composed of a water-reducing component and an accelerating component.As mentioned above, the AE water-reducing agent of the present invention is a so-called chloride-free type that does not contain problematic chlorides such as CaCl2. It has the advantage of not having a negative effect on the reinforcing steel in the concrete. This AE water reducing agent is characterized by containing a naphthalene sulfonic acid dispersant.

As the naphthalenesulfonic acid dispersant, a formalin condensate of naphthalenesulfonic acid and a formalin cocondensate of naphthalenesulfonic acid and ligninsulfonic acid are used.

[Means for solving the problem] Using a naphthalene sulfonic acid dispersant alone causes a large decrease in slump, and lignin sulfonate m, which is a water-reducing component,
In Germany, it has the disadvantage of having a large setting delay. When this naphthalene sulfonic acid-based dispersant is combined with lignin sulfonate in an appropriate ratio, it has the effect of suppressing setting retardation and improving water reduction properties, and further enhances the setting accelerating effect of thiocyanate and triethanolamine. We have discovered that there is a function, and have completed the present invention.

The AE water reducing agent of the present invention is 0) Lignosulfonate 100 parts by weight.

■20 to 100 parts by weight of a naphthalene sulfonic acid dispersant.

■1 part of thiocyanate 50-20%.

) Triethanolamine (T, E, A) 1-1O
Weight part.

The amount used is 0.05 to 0.50% by weight based on cement, and while maintaining high water reducing properties, it has a setting promotion effect comparable to that of conventional AE water reducing agents containing chlorides. You can get it.

[Effect]

The AE water reducing agent of the present invention contains a lignin sulfonate and a naphthalene sulfonic acid dispersant in the above ratio.

It is made by blending thiocyanate and triethanolamine, but if more than 100 parts by weight of naphthalene sulfonic acid dispersant is used for 100 parts by weight of lignin sulfonate, the change in slump over time will deteriorate significantly. ,2
If the amount is less than 0 parts by weight, almost no improvement in water-reducing properties is observed.

If the thiocyanate is used in an amount less than 50 parts by weight, the accelerating effect will be significantly reduced, and if it is used in an amount exceeding 200 parts by weight, the accelerating effect will reach a plateau, so it is not necessary to use more than 200 parts by weight. If less than 1 part by weight or more than 10 parts by weight of triethanolamine is used, the setting promotion effect will be significantly reduced.

〔Example〕

The present invention will be specifically explained below with reference to Examples, and the materials used in the concrete tests are as follows.

Cement: W-through boltland cement specific gravity 3.16 Fine aggregate: Kashima mountain sand/Kodama mountain sand = 7/3F, M, 2
．． 65. Specific gravity 2.62. M, 5. 5m/m coarse aggregate: Chichibu crushed stone F, M, 6.83. Specific gravity 2.70. M, 3.20
m/m water: tap water AE agent: target air tt4±1 except for plain concrete
An appropriate amount of anionic AE agent was used so as to maintain the same %.

In each example, the AE water reducing agent was 1 to 4 for cement.
It was added at the ratio shown in the table.

Lignosulfonate is lignin, naphthalenesulfonic acid dispersant is NSF, thiocyanate is Na5CN
.

Triethanolamine is written as T, E, A.

Margin Example 1 Table 1 shows the results of concrete tests using the above formulations.

Blend concrete and one lacking lignin or N, S, F was used as a control.

The slump value after 30 minutes is the static F of the concrete on the mixing board.
This is the ramp value after 30 minutes when t is turned on.

Margin Example 2 Table 2 shows the results of concrete tests using the above formulations.

As a control example, one using blended concrete and calcium chloride as an accelerator, one lacking T, E, and A;
Those with less and more TJ and A were used.

Example 3 Table 3 shows the results of a concrete test using the same mix as in Example 2. As control examples, preconcrete, one using calcium chloride as an accelerator, one lacking Na5CN, one with less Na5CN, and one with more Na5CN were used. The one containing a large amount of NaSCN showed better coagulation and one-day strength than the example, but it had already reached a plateau.

Example 4 Table 4 shows the results of a concrete test using the same mix as in Example 2.

Preconcrete as a control and Na as an accelerator
For comparison with 5CN, calcium chloride, sodium thiosulfate, calcium nitrite, and calcium nitrate were used.

The following margin [Effects of the invention] When the AE water reducing agent of the present invention is used, as shown in the examples, the setting time is shortened and results with excellent short and long-term strength are obtained, and its performance promotes calcium chloride. The product of the present invention has the advantage that it does not contain chloride, so there is no risk of corrosion of reinforcing bars.

Patent applicant: Sanyo Kokusaku Pulp Co., Ltd. Procedural amendment June 3, 1986

Claims (1)

[Claims] 1 For 100 parts by weight of ligninsulfonate, 20 to 100 parts by weight of a formalin condensate of naphthalenesulfonic acid or a formalin cocondensate of naphthalenesulfonic acid and ligninsulfonic acid, and 50 to 20 parts by weight of thiocyanate.
0 parts by weight, and further contains 1 to 10 parts by weight of triethanolamine.