JPS5815061A - Manufacture of independent foam-rich lightweight foamed concrete - 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 relates to a method for producing lightweight cellular concrete rich in closed cells.

The lightweight cellular concrete referred to in the present invention is generally referred to as ALO, and is made by adding finely pulverized silicic acid raw materials, calcareous raw materials, and various additives as necessary.
and 5102 (hereinafter referred to as the mixed raw material) is mixed with an appropriate amount of water and aluminum metal powder to form a slurry, and this slurry is poured into the mold. The product is foamed and solidified, and when it reaches a certain degree of hardness, it is cut into specified dimensions and steam-cured at high temperature and pressure in an autoclave to obtain a bulk specific gravity of 0.45~
It is about 0.55. Silica stone, clay sand, fly ash, blast furnace slag, etc. are used as silicic raw materials, quicklime, slaked lime, etc. are used as calcareous raw materials, and other additives include ordinary Portland cement, etc. Various inorganic cements are used.

The present inventors have incorporated a larger amount of closed cells into conventional lightweight cellular concrete to create a lightweight cellular concrete with greater strength.
We conducted various research in an attempt to create cleats.

The first method that can be considered is to increase the amount of aluminum metal powder added to the conventional blended raw materials, or to add more kneading water to the blended raw materials, but the former method results in the generation of too many bubbles. Therefore, the resulting aerated concrete has low strength because the generated air bubbles coalesce or defoam and float to the surface of the slurry of mixed raw materials.
It becomes heterogeneous. In addition, in the latter method, the viscosity of the slurry of the mixed raw materials decreases too much, causing phenomena of solid-liquid separation and defoaming, making it impossible to produce aerated concrete.

Therefore, the present inventor added an appropriate amount of water to the blended raw materials, kneaded them, added aluminum metal powder and kneaded them to create a slurry, poured this slurry into a mold, and placed the mold together with the slurry in a pressure reducer. We have conducted various research on methods of placing slurry in a vacuum container, foaming it, and solidifying it under specific conditions, and found that when the slurry is solidified under reduced pressure, the foamed gas is almost uniformly distributed within the lightweight concrete, which is created as closed cells. , and discovered that by adjusting the viscosity of the mixed raw material slurry, adjusting the amount of aluminum metal powder, the viscosity of the slurry, and the degree of vacuum, it was possible to create various products with different bulk specific gravity in which closed cells were uniformly distributed in concrete. did. Bulk specific gravity refers to the specific gravity of a product dried at a temperature of 100°C until it reaches a constant weight. The bulk specific gravity' described below was measured using the same method as above.

Next, the experimental results will be explained.

[Experimental Example 1] 60 kl of silica stone with a fineness of 2800 crf/ (Blaine value), 10 kg of quicklime with 10% sieve residue of 88 microns, and 30 kP (ordinary Portland cement) are mixed, and the molar ratio of OaO and 8102 in the mixed raw materials is 0.52), 702 parts of water was added to 100 parts of this mixture, and after kneading for 1 minute, aluminum metal powder 62F! - was added and kneaded for further 1 minute to produce a viscosity of 500 cps (B-type viscometer).

This slurry was separately injected into three molds with a capacity of 300 mm, each was placed in a pressure reducer, and after removing the air in the pressure reducer, the inside was divided into (1) -1oo, (2) -400, (3)
The pressure was reduced to 600 lllHg to foam and solidify.

Next, this solidified material was taken out and put into an autoclave and cured at 180°C for 15 hours. The resulting lightweight aerated concrete was dried at 100°C until it reached a constant weight, the bulk specific gravity was determined, and the compressive strength was measured. The results shown in Table 1 below were obtained.

Compressive strength here refers to the strength when the product is dried at 70°C until the moisture content in the product reaches 10%. The compressive strength described below was also measured using the same method as above.

For comparison, the same amount of water and aluminum metal powder as above were added to the same blended raw materials as above and kneaded, put into the same mold as above, foamed and solidified under normal pressure, and the solidified product was the same as above. The results of autoclave curing under these conditions are also listed in Table 1.

Table 1 Based on the above experimental results, the slurry viscosity of the blended raw material (500 cp
s) and when the amount of aluminum metal powder added is constant, the larger the degree of vacuum in the pressure reducer, the larger the diameter of the bubbles in cellular concrete, and the bubbles formed are all independent spherical. It was recognized that the Moreover, even if the amount of aluminum metal powder added is reduced -350 liters
Lightweight aerated concrete with a bulk specific gravity of about 0.45 can be obtained by reducing the pressure to about 1Hg, and -100 DragonHg
If the pressure is reduced to a certain degree, lightweight aerated concrete with a bulk specific gravity greater than 0.45 can be obtained, but it is recognized that the generated air bubbles are uniformly distributed within the lightweight concrete, resulting in a product with high compressive strength. It was done.

On the other hand, when lightweight cellular concrete is made by foaming the mixed raw material slurry in the air and then autoclaving it, the air bubbles contained in the concrete are often uneven and have horizontal cracks, and the bulk density It was recognized that the compressive strength was low even though it was high.

[Experimental Example 2] Using raw materials with the same powderiness as those used in Experimental Example 1,
Mix 70ky of silica sand, 13kl of quicklime, and 17kp of ordinary Portland powder, add 55kg of water to 100kg of this mixed raw material, mix for 1 minute, and then add 40kg of aluminum metal powder. and 12 oz were added and kneaded for an additional minute to make a slurry (viscosity 1500 cps). This slurry was separately injected into six molds each having a volume of 300 A, and placed in a pressure reducer to remove the air inside the molds. -400 for sample n, -500 for (5), -600 for sample n, -50 for sample n, -100 for (8), -100 for sample n. When -30
The pressure was reduced to 0 1Hg to foam and solidify. Next, this coagulated material was taken out and placed in an autoclave, both at 180°C.
After curing for 15 hours, the resulting lightweight cellular concrete was dried at 100°C until it reached a constant weight, and the bulk specific gravity was determined.
The compressive strength was also measured and the results shown in Table 2 below were obtained.
'1 For comparison, Table 2 shows the results of adding the same amount of water and aluminum metal powder to the same blended raw materials as above, foaming and solidifying the material, and then curing the solidified material in an autoclave under the same conditions as above. It is also listed as a comparative example.

Table 2 From the above experimental results, the slurry viscosity of the blended raw material was set to 1600.
When cps is kept constant and the amounts of Al and Minilam metal powder added are varied, a product with closed cells uniformly dispersed in lightweight cellular concrete can be obtained in both cases, but the degree of vacuum that foams the slurry varies depending on the amount of added aluminum metal powder. The larger the amount, the lower the degree of pressure reduction, and as in Experimental Example 1, it was found that as the degree of reduction was increased, the bulk specific gravity became smaller.

[Experimental Example 3] Using raw materials with the same particle size as those used in Experimental Example IK, 55 kp of silica sand, 30 kp of quicklime, and 15 kII of ordinary Portland cement were mixed, and 100 k of this mixed raw material was prepared.
75 grams of water! was added, and after kneading for 1 minute, aluminum metal powder 55f! - was added and kneaded for further 1 minute to prepare a slurry (viscosity: 360 cps). This slurry was injected into a mold with a volume of 3002, put into a pressure reducer together with the mold, and after removing the air inside the container, the internal pressure of the container was reduced to -40011.
The pressure was reduced to 1HH to foam and solidify. Next, this solidified material was taken out and placed in an autoclave and cured at 180℃ for 15 hours.The obtained lightweight cellular concrete was dried at 100℃ until it reached a constant weight, the bulk specific gravity was determined, and the compressive strength was measured. No.

The results shown in 3 tables were obtained.

For comparison, the same amount of water and aluminum metal powder as above were added to the same blended raw materials as above and kneaded, then put into the same mold as above and foamed and solidified under normal pressure. Products obtained by autoclave curing under the same conditions as (conventional method products) are also listed in Table 3.

Table 3 From this result, if you want to obtain a product with the same bulk specific gravity as lightweight cellular concrete obtained by the conventional method, use approximately 1/2 the amount of aluminum metal powder in the conventional method, and use a slurry of -4001
It is recognized that the product can be obtained by foaming and solidifying under reduced pressure of @lHg and then curing in an autoclave as in the conventional method. Moreover, according to the method of the present invention, the air bubbles in the lightweight aerated concrete container obtained were well-aligned at about 2 to 3111, and the compressive strength was high, but the air bubbles in the lightweight aerated concrete obtained using the conventional method were uneven and the cells broke. It was found that some of the products were combined, and the compressive strength was also lower than that of the products made according to the present invention.

The above experimental examples all illustrate cases where aluminum metal powder is used as a foaming agent, but similar results can be obtained when metal powders other than aluminum metal, such as zinc or barium, are used. It was done.

The present invention is based on these findings, and aims to reduce OaO in mixed raw materials such as niic acid raw materials, calcareous raw materials, and other binders in KM for producing light, high-volume cellular concrete.
and 5102 in a molar ratio of 0.3 to 0.8 to 100 parts by weight of the raw material, and 0.03 to 0 parts by weight of water.
．． Add a blowing agent of 15 and knead to reduce the viscosity of the slurry to 3.
00~1600 ape adjusted to -50 degree of vacuum
~-600lllHg This is a method for producing lightweight cellular concrete rich in closed cells, which is characterized by foaming and solidifying under reduced pressure of 4C and then curing in an autoclave.

In the present invention, the siliceous raw materials used include silica sand, silica stone, fly ash, blast furnace slag, etc., with a powder degree of 88μ sieve residue 3
Calcareous raw materials include quicklime, slaked lime, powder with particle size of 88 microns and sieve residue of 10% or less, and other binders include Portland cement, mixed cement, alumina cement, etc. is used. Further, as the blowing agent, there are used metal powders which generate hydrogen when reacting with an alkaline aqueous solution, such as powders of aluminum metal, zinc metal, barium metal, and alloy metals of copper and aluminum.

Next, in the method of the present invention, the amount of blowing agent added, the slurry viscosity of the raw material for preparation, and the degree of pressure reduction for the slurry are closely related to each other.
If the cps is not grooved, solid-liquid separation of the slurry will occur, so it cannot be used, and the slurry viscosity is 1600.
When the slurry exceeds the ape, the viscosity is too high and the cell density will be different between the upper and lower layers of the lightweight cellular concrete produced, so it is inappropriate to use a slurry with a high viscosity.

Therefore, the viscosity range of the raw material slurry used in the present invention is preferably 300 to 1600 cps, more preferably 400 to 700 cps. Next, if the amount of blowing agent added is small, the degree of vacuum can be increased, and if it is large, the degree of vacuum can be decreased to produce the desired lightweight cellular concrete IJ+ product, but from an economical point of view, the blowing agent is The amount is 0.03 to 0.15 parts by weight, preferably 0.05 to 0.10 parts by weight, based on 100 parts by weight of the raw material. The reduced pressure on the slurry is preferably -50 to -600 Hg, more preferably -300 to -500 Hg.
It is Hg.

According to the present invention, by appropriately adjusting the slurry viscosity of the blended raw material, the amount of blowing agent added, and the degree of reduced pressure for foaming and solidifying the blended raw material slurry, it is possible to create strong, lightweight cells containing closed cells with a desired specific gravity. concrete can be easily produced.

Example: Silica stone 60 to 1.
10kl of quicklime with 5% residue on 88μ sieve and ordinary Portland cement h3sky are mixed and OaO and 81
02 molar ratio is 0.6), 70A of water was added to 100kjL of this mixture, and after stirring for 1 minute, aluminum metal powder 62? was added and kneaded for another minute until the viscosity was 500 a.
pe (Type B viscometer) slurry was made. 300 for this slurry! The mixture was poured into a mold, placed in a pressure reducer, and after removing the air inside the container, the pressure was reduced to -400 lllHg to foam and solidify. Next, this coagulated body was taken out, placed in an autoclave, and cured at 180°C for 15 hours.

The bulk specific gravity of the lightweight cellular concrete obtained was 0.35.
The compressive strength is 42 yen 1, and the bubble diameter in the product is 1.5 ~
2.0II11, all of them were closed cells.

Procedural amendment (spontaneous) August 10, 1980 Commissioner of the Japan Patent Office Shima 1) Haru Judono 1, Indication of the case Patent Application No. 1983-95347 2, Name of the invention Manufacture of lightweight foam co-crete rich in closed cells Method 3: Relationship with the person making the amendment Patent applicant: 6276 Oaza Onoda, Onoda City, Yamaro Prefecture (024) Onoda Shichiment Co., Ltd. (and 1 other person) 4. "Detailed description of the invention" in the agent's specification Column 6, the statement of contents of the amendment, shall be amended as follows.

(1) Add the following words between page 7, line 3, ``preparation'' and ``,''.

[(The molar ratio of OaO and 5i02 in the blended raw materials is 0.38)
J(2) Page 9, line 9, add the following phrase between ``preparation'' and ``,''.

(The molar ratio of OaO and 5i02 in the blended raw materials is 0.78)
J (3) Page 13 bottom line r60kfJ to r55kfPJ
Correct.

(4) Page 14, line 3, “The molar ratio is 0.6” is changed to “The molar ratio is 0.
．． Corrected to 604.

37

Claims (1)

[Claims] In producing lightweight cellular concrete, (
ao (!: The ratio with 5in2 is 0.3 to 0.0 in molar ratio.
Water and 0.0 parts by weight for 100 parts by weight of the mixture in the range of 8.
A characteristic feature is that 3 to 0.15 parts by weight of a blowing agent is added and kneaded to adjust the slurry viscosity to 300 to 1600 cps, which is then foamed and solidified by reducing the pressure to a degree of vacuum of -50 to -600 lllHg, and then curing in an autoclave. A method for producing lightweight cellular concrete rich in closed cells.