JPS61117142A - Cement composition - 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] Industrial Application Field: This invention relates to a novel cement composition,
More specifically, aldehydes and bisulfites represented by the general formula %() (wherein R means hydrogen or lower alkyl), or addition compounds of the aldehydes and bisulfites, and water-soluble thiocyanides. The present invention relates to a cement composition comprising an acid salt.

Conventional technology 2 Calcium chloride, which has been commonly used to accelerate the hardening of cement compositions and has a large hardening effect, causes corrosion of the reinforcing bars in the concrete and rusts the iron. Therefore, instead of calcium chloride, technology that uses an adduct of formaldehyde and sodium bisulfite (for example, special Kaisho 5
4-6013), Technique 1 using thiocyanate (for example, see JP-A-58-79853)
, a technique using a thiocyanate and a nulphonated melamine-formalin condensate (e.g., JP-A-59-83968)
(see Publication No. 1), etc. are known.

Problems to be solved by the invention: However, these hardening accelerators that replace calcium chloride do not have sufficient strength after hardening of cement compositions. It is hoped that a curing accelerator that increases the

Means for solving the problem between mt and When a hydrogen sulfite or an addition compound of the artificial acid (I) and a hydrogen sulfite and a water-soluble thiocyanate are used in combination, the combined effect makes it possible to obtain a cement composition with sufficient strength after hardening. Moreover, they obtained new knowledge that it also has an early-strengthening effect, and completed this invention.

The cement composition of the present invention is characterized in that the aldehyde and hydrogen sulfite represented by the formula (1) or the aldehyde and hydrogen sulfite are added to a kneaded product containing cement, which is a hydraulic substance such as cement paste, grout, or concrete, as a hardening component. It means a kneaded product containing an addition compound with and a water-soluble thiocyanate.

Examples of the hydraulic cement include ordinary Portland cement, sulfate-resistant cement, blast furnace cement, and fly ash cement.

In the formula (I), examples of lower alkyl in R include methyl, ethyl, propyl, etc., and specific examples of the aldehyde represented by the formula (I) include homo/redehyde, acetaldehyde, propionaldehyde, etc. Can be mentioned.

Preferred examples of bisulfite include alkali metal hydrogen sulfite salts such as sodium hydrogen sulfite and potassium hydrogen sulfite, and alkaline earth metal salts of hydrogen sulfite such as calcium hydrogen sulfite and magnesium hydrogen sulfite.

Furthermore, the addition compound of the aldehyde represented by the above formula (I) and a hydrogen sulfite salt can be represented by the following formula (II).

(R-CH-SO3)nY (II) [In the formula, R has the same meaning as ox in the above formula (I), Y is a monovalent metal or 几 is a divalent metal, and n is an integer of 1 or 2. means, Y is 1
If Y is a valent metal, n is 1; if Y is a divalent metal, n is
is 2] Among the compounds represented by the above formula (U), the most preferred compound is sodium hydroxymethanesulfonate.

Preferred examples of water-soluble thiocyanates include alkali metal thiocyanates such as sodium thiocyanate, alkaline earth metal thiocyanates such as calcium thiocyanate, and ammonium thiocyanate.

As described above, the present invention uses aldehyde (■), hydrogen sulfite, and water-soluble thiocyanate together as cement hardening accelerators, or the method is based on the use of aldehyde (■), hydrogen sulfite, and water-soluble thiocyanate, or
) and hydrogen sulfite (IT) is obtained, and this and a water-soluble thiocyanate are used together in cement.The content of these hardening accelerators in the cement composition is The degree described below is continuous light (all values below are weight % with respect to cement), and if it is less than this range, the effect is insufficient, and please be aware that if it is less than this range, it is too much. The degree of effect in case #9 is almost the same as this range, so it is uneconomical to increase the range beyond this range.

Artefact (I): 0.01-0.22
% (preferably 0.02-0.11%) Bisulfite: 0.04-0.78% (preferably 0.08-0.39%) Addition compound (71): 0.05-1.0
% (preferably 0.1-0.5%) Water-soluble thiocyanate: 0.05-160%
(Preferably 0.1 to 0.5%) Water reducing agents conventionally used in the cement composition of the present invention (e.g., sodium gluconate, lignin sulfonate, naphthalene sulfonic acid formalin I compound, sulfonated It is possible to improve the quality of Funcli-1. etc. by adding admixtures such as melamine-formalin condensates, etc.) and AE agents.

The hardening accelerator in the cement composition of the present invention can be added to the cement by any conventionally known method.

Effects of the invention: The cement composition of the present invention accelerates setting and hardening due to the combined effects of aldehyde (I), bisulfite or an addition compound of the aldehyde and bisulfite, and water-soluble thiocyanate, and improves the initial material age. The strength development is greater than that of conventional products), the effect is remarkable at low temperatures, and the strength at long ages is also enhanced.

i In addition, bisulfite and the addition compound of bisulfite and aldehyde (I) in the cement composition of the present invention
I) A temporary water reduction effect was also observed, which also contributed to the increase in initial strength.

Next, the effects of this invention will be specifically explained using test examples.

Test Example 1 (1) Conditions for Concrete Test The concrete test was conducted in accordance with the Japanese Industrial Standard A 6204 standard for chemical admixtures for concrete.

The cement used was ordinary Bo/Retland cement (a mixture of three equal amounts of Onoda cement, Asano cement, and Sumitomo cement, specific gravity: 3.16), and the fine aggregate was Fuji Tokawa sand (FM = 2.66). , specific gravity: 2.64), coarse aggregate is crushed stone from Kasama (Gm8.X = 20 am, FM
= 6.69, specific gravity: 2.66).

The curing temperature was 5℃, the amount of cement was 32oKg/m3, the proportion of fine aggregate was 50%, and the slump was 18cmfr. The results are shown in Table 1.

Test Example 2 (1) Conditions for Concrete Test A test was conducted by adding sodium gluconate, a commercially available water reducing agent, to each admixture. The concrete mix is slump 1
A plain concrete mix of 8 was determined, and the amount of water (4.3%) corresponding to the effect of the water reducing agent (sodium gluconate) was reduced from the plain concrete mix, and the mixture was mixed.Other concrete test conditions were the same as Test Example 1. The results of tests conducted under similar conditions are shown in Table 2.

Test, Inspection 3 (1) Concrete Test Conditions: Curing temperature was 20°C, and other conditions were the same as in Test Example 2. All tests were conducted under the same concrete test conditions.

The results are shown in Table 30 Next, examples of this invention will be shown.

Example 1 (Cement paste) (Kg/m3) Ordinary Portland cement 1623 water
48 Sodium Mathiocyanate 4.869 Sodium Hydroxymethanesulfonate 3.246
(Water/cement ratio: 30%) Mix the above to make a cement paste.

Example 2 (Grout for PC) (Ky (m3) Ordinary Portland cement 150° water
525 Alumina powder 0.09 Sodium thiocyanate 4.500 Sodium hydroxymethanesulfonate 3.000 (water/cement ratio 35%) The above are mixed to make PC grout.

Example 3 (Mortar) (Kg/m”) Ordinary Portland cement 600 water
356 sand
120゜Sodium thioneanate 1.800 Sodium hydroxymethanesulfonate 1.200 (Water cement ratio 59.3%) Mix the above to make a molar ratio μ0 Example 4 (Concrete) CKy/m3) Ordinary Portland cement 319 water
190 sand
892 gravel
880 Sodium thiocyanate
0.95'i' Hydroxymethane ρ Sodium phonate 0.638 (water/cement ratio 60
%, fine aggregate ratio 5o, 5%) The above is mixed to make concrete.

Patent applicant: Fujisawa Pharmaceutical Co., Ltd. Procedural amendment (formality) %formula% 1.Display of the incident 1981 Patent Application No. 236195 2. Name of the invention cement composition 3. Person who makes corrections

Claims (3)

[Claims] (1) Cement containing an aldehyde and hydrogen sulfite represented by the general formula R-CHO (wherein R means hydrogen or lower alkyl) or an addition compound of the aldehyde and hydrogen sulfite, and a water-soluble thiocyanate Composition. (2) The cement composition according to claim 1, which contains formaldehyde, sodium bisulfite, and sodium thiocyanate. (3) A cement composition containing sodium hydroxymethanesulfonate and sodium thiocyanate.