JPH1045454A - Production of waterproof cement compound and method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low-cost, lightweight and crack-free waterproof concrete compd. by subjecting a higher-density dry kneaded mixture obtd. by dry kneading volcanic ashes or volcanic pebble powder and cement and customarily used additives to dry kneading. SOLUTION: The higher-density dry kneaded mixture is obtd. by dry kneading (A) 30 to 50 parts by volume volcanic ashes or volcanic pebble powder having a grain size below 2mm, (B) 15 to 25 parts by volume powder having a grain size of 2 to 4mm and (C) 20 parts by volume cement and packing the fine grains of the volcanic ashes or frictionally crushed fine pieces generated during the dry kneading into the pores of the relatively coarse volcanic particles to increase the density of the mixture. The customarily used additives are added at need to such higher-density dry kneaded mixture and the dry kneading is continued, by which the cement is adhered to the surfaces of the higher-density volcanic ashes grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof concrete method, a method for producing a waterproof cement composition used in the method, and an aggregate obtained by denaturing a material derived from volcanic ash or lapilli.

[0002]

2. Description of the Related Art As a means for waterproofing concrete structures, a waterproofing agent such as sodium silicate or a silica-based compound is used to improve the waterproofness of concrete by combining it with lime, which is a hydration product of cement. A method of forming insoluble lime to fill voids; metal soap,
There is a method of producing water repellency by wax; a method of improving waterproofness by blending a resin emulsion, and the like.

Further, as a means of waterproofing a concrete structure, there is a method of waterproofing a concrete surface, a method of forming a waterproof layer using asphalt, and a method of blending a cement waterproofing agent with cement or mortar on the surface of the structure. There are a method of applying and applying, a method of applying a solution or emulsion of a synthetic resin or synthetic rubber to form a waterproof layer or a waterproof sheet, and a method of painting with a waterproof paint.

[0004] These conventional concrete waterproofing methods are:
The use of special additives, expensive waterproofing materials, complicated and large amounts of labor and time, all require large expenses, and when using organic materials, , Relatively short service life (for example, 4-5
Year), there are drawbacks that require frequent repairs and rebuilds.

A more serious problem is that cracks are likely to occur in the concrete part, and even a slight crack not only impairs the appearance of the building due to the invasion of rainwater and the like, but also causes mold, deterioration of the living environment, and storage environment. (In the case of a warehouse or the like). It is also well known that the cracks once formed grow and develop under various climatic conditions, exacerbating the problem.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has studied various problems associated with the conventional concrete waterproofing as described above, and has carried out test and research in order to solve those problems. Water-resistant waterproof concrete composition and waterproof construction method using the same were studied.

[0007]

SUMMARY OF THE INVENTION Thus, the present invention relates to a porous material of volcanic ash or lapilli (typically "pumice").
Combining the relatively coarse particle portion and the relatively fine particle portion obtained from at a specific ratio, kneading them,
These pores are filled with much finer volcanic ash particles, the pore openings are closed, and the densified volcanic ash powder is dry-mixed with cement, then water is introduced and wet-kneaded, and this mixture is placed at the work site. By coating and compacting the mixture and curing and curing, an excellent waterproof layer without cracks can be formed.

Accordingly, the present invention relates to (1) powders having a particle size range of less than 2 mm obtained from volcanic ash or lapilli of 30 to 5;
0 parts by volume (A ₁ ) and 15 to 25 parts by volume (A ₂ ) of powder having a particle size range of ₂ mm to 4 mm; and 20 parts by volume of cement (B) are prepared. (2) The above (A ₁ ) and (2) a ₂₎ combined with empty dough to relatively coarse ash into the pores of the volcanic particles fine particle or densification conditions and without the grinding砕微strip that occurs during the air kneading is filled, (3) Water-proofing property comprising introducing the above-mentioned (B) and optionally a conventional additive into the densified hollow kneading mixture and further continuing the kneading to adhere cement to the individual surfaces of the densified volcanic ash grains densely. A method for producing a cement formulation is provided.

Further, the present invention relates to (1) a powder having a particle size range of less than 2 mm obtained from volcanic ash or lapilli of 30 to 50.
Volume ₁ (A ₁ ) and powder 1 having a particle size range of 2 mm to 4 mm
5 to 25 parts by volume (A _2); Cement 20 parts by volume (B);
And 20 to 25 parts by volume of water (C) are prepared.
₁ and A ₂ and the combined sky kneaded to relatively coarse ash into the pores of the volcanic particles fine particle or densification conditions and without the grinding砕微strip that occurs during the air kneading is filled, (3 (4) The above-mentioned (B) and, if desired, conventional additives are introduced into the densified hollow kneading mixture, and further the air kneading is continued to cause cement to adhere to the individual surfaces of the densified volcanic ash grains, and (4) Thereafter, (C) is introduced and wet-kneaded, and (5) a waterproof concrete method is also provided in which the resulting mixture is placed in a predetermined position and compacted to eliminate air bubbles.

The present invention further provides an aggregate made of volcanic ash or volcanic gravels, wherein the pores are filled with fine volcanic ash particles to make the pore openings closed and densified. Also provide.

According to the present invention, powders derived from volcanic ash (or lapilli) in two particle size distributions, namely in the range of less than 2 mm and in the range of 2 mm to 4 mm, and particles of different sizes for the combined use of the powders. It is observed by a microscope that the particles show a tightly packed state, and that when they are kneaded together, fine volcanic ash particles fill the pores peculiar to volcanic ash or lapilli, closing the pore openings and increasing the density.

[0012] When cement is blended with the aggregate of such densified volcanic ash or lapilli and continuous kneading continues, relatively fine cement powder is added to the surface of each particle of the relatively large aggregate. Are brought into close contact with each other, and small irregularities on the surface of the aggregate are also filled with the cement powder. In this kneading stage, a colorant such as a conventional additive or a pigment can be introduced, if desired.

The present inventor has focused on the special behavior and properties of the humic allophane soil generated by the volcanic ash sediment undergoing long-term weathering, and has considered various industrial uses thereof, for example, in Japanese Unexamined Patent Publication No. No. 71414, 8-895
No. 65, No. 8-134499, etc., but when the humic allophane soil powder is added at the above-mentioned aggregate / cement empty kneading stage, rust-proofing, mold-proofing, and stain-proofing properties are obtained. It has been discovered that (moss-proofing), deodorizing and dew-condensing properties are imparted. Given such characteristics, it is very suitable for construction in basements, water storage tanks, kitchens, water treatment plants, hospitals and the like.

Now, as described above, the densified aggregate / cement formulation that has been kneaded is then slumped to 6-10.
cm of water.

If volcanic ash (or lapilli), cement and water are mixed at the same time, water adheres around the gas escape pores (pores) of the volcanic ash, and the cement becomes a paste and hydrates with water first. It was observed that the cement became a hydrate, and the good adhesion of cement to the volcanic ash aggregate was hindered, leaving many pores as they were.

The kneaded mixture of the densified aggregate / cement formulation according to the invention and water is then used at the construction site. Compaction at the time of driving can be performed by a conventional method. For example, rolling is performed by using a trowel to uniformly spread and finish while discharging air bubbles in the concrete (at this time, the slump value of the concrete is approximately 6 cm). ). In large-scale construction, as is well known, a vibrator, for example, an internal vibrator, a form vibrator, and a surface vibrator are used to form dense concrete with no air bubbles or voids, and also to form around the rebar and formwork. Make sure that it is well distributed throughout.

A test example of densification of the powder (A ₁ ) of volcanic ash (volcanic rubble) having a particle size range of less than 2 mm and the powder (A ₂ ) having a particle size range of 2 mm to 4 mm according to the present invention is shown. It is as shown below.

Volcanic ash (pumice) from Furue, Kanaya City, Kagoshima Prefecture
From (A ₁ ) having a particle size of 0 to 1.0 mm 30
With a capacity part and 1.0 mm to 2.0 mm (less than) 40
Capacitance part is taken, and (A ₂ ) is 2.0 mm (or more)
30 volume parts of ~ 3.0 mm were taken. The above (A ₁ )
And (A ₂ ) had an initial specific gravity of 0.980. Rotary vibration motor (Temex; 3,
450v. p. m), the mixture was placed in a concrete mixer (manufactured by Asaka Kogyo Co., Ltd .: 45 rpm), and the mixture was kneaded under vibration and sampled over time to measure the specific gravity of the mixture. Was obtained.

In the above experiment, a high density of about 15% was achieved. When the mixture before kneading was observed under a microscope, many gas escape holes (pores) peculiar to volcanic ash were clearly recognized. However, after kneading, the gas escape holes were substantially turned to the back by fine volcanic ash granules. It was confirmed that the condition was obstructed. Therefore, when mixed with cement or water later, the amount of air existing in the gas escape holes (pores) is small, so that it is considered that a dense, high-strength cured product is given without any adverse effect. The compactness of the cured product and the small amount of residual air bubbles were clearly recognized by a microscope.

FIG. 1 shows an example of the particle size distribution of the (A ₁ ) and (A ₂ ) components of volcanic ash (or lapilli) suitable for use in the present invention. The solid curves in FIG. 1 represent fine and coarse aggregates (ie, sand, gravel) customary in concrete.
Is a representative example of the particle size distribution of, and is shown for comparison. As is apparent from this figure, the fine component (A ₁ ) and the coarse component (A ₂ ) derived from the volcanic ash or lapilli of the present invention are significantly more remarkable than the conventional fine aggregate (sand) and coarse aggregate (gravel), respectively. It is used in combination with a small particle size distribution, and undergoes the unique kneading and densification treatment as described above.

The composition of the cement composition according to the present invention has a fine component (A ₁ ) of 30 parts by volume based on 20 parts by volume of cement.
50 parts by volume, preferably 35 to 45 parts by volume and coarse component (A ₂₎ 15 to 25 parts by volume, preferably 17 to 23 parts by volume. Here, the amounts of (A ₁ ) and (A ₂ ) are the amounts before the kneading and densification treatment.

The kneading of the mixture of the fine component (A ₁ ) and the coarse component (A ₂ ) is carried out with a common concrete mixer to about 3 to 5 times.
Minutes, for example, about 4 minutes, appropriate densification can be achieved.
(Up to about a minute) can be used, which seems to be preferred for the performance of concrete.

A required amount of cement is introduced into the high-density empty kneading (A ₁ + A ₂ ) mixture, and the empty kneading is further performed by 2 hours.
By continuing for about 5 minutes, usually about 3 minutes, the cement formulation of the present invention can be obtained.

When this cement composition is to be used immediately for construction, water (about 20 to 25 parts by volume based on the volume parts of A ₁ , A ₂ and cement) is added to the cement composition in the mixer and kneaded. To obtain a kneaded product having a slump value of 6 to 10 cm. During kneading, the water is absorbed by the cement adhering to the aggregate, which promotes good access and contact of the cement with the aggregate due to the absence or small number of bubbles in the pores of the aggregate.

[0025] A considerable amount of water separates to the upper part due to the operation of the iron during compaction, the pressure of the vibrator, and the action of shaking during compaction, and the compacted (before hardening) construction has a slump value. It shows about 5-7 cm, and the strength of the lightweight concrete obtained by hardening and curing this is about 130 kg /
cm ² .

The construction can also be performed by a spraying method, for example, by spraying on a mortar wall or the like to obtain a crack-resistant surface having high waterproof, soundproof and heat insulating properties.

The waterproofness achieved by the waterproofing concrete method of the present invention is in the range of 0.19 to 1.74% (water absorption) as measured by JIS A 6101, and such a value is about the same as that of ordinary concrete. Much lower than around 10%.

It has been mentioned above that humic allophane earth powder can be added to the cement composition of the present invention. In this case, for example, chlorine in tap water is removed and other metal ions are also removed. Corrosion resistance of a member, for example, a reinforcing bar or a steel frame, is improved.

[0029]

[Example] 40 l of fine components with a particle size of less than 2 mm derived from volcanic ash
Then, 20 l of a coarse component having a particle size of 2 mm to 4 mm derived from lapilli were charged into a concrete mixer and kneaded for 4 minutes. Then, 20 l of ordinary Portland cement was added to the kneaded mixture, and the kneading was continued for 2.5 minutes. And kneaded to obtain a kneaded material having a slump value of 8 cm.

The apparent specific gravities of the aggregate mixture before and after kneading are 0.977 and 1.114, respectively, and the pores of the individual particles in the aggregate mixture after kneading are substantially fine powders. Microscopic observation showed that it was exhausted.

The above-mentioned kneaded material having a slump value of 8 cm is pushed to a thickness of about 13 mm on a rough surface of a ready-made concrete and rolled with an iron, so that considerable moisture is transferred to and separated from the surface while eliminating accompanying air bubbles. It was left to solidify and cure (7 days old).

Comparative Example 1 In the operation of the above example, fine components, coarse components and cement were charged together in a mixer, kneaded for 4 minutes, and then kneaded with water, followed by similar construction and curing. (March 7th).

Comparative Example 2 In the operation of the above example, fine aggregate made of conventional sand was used.
Mortar was prepared from cement and water, and was similarly constructed and cured (7 days old).

The water absorption of each sample of the above-mentioned material age (JIS A
6101) was as follows. Example 1.61% Comparative Example 1 13.7% Comparative Example 2 10.2%

When the finished surface was observed one year later, no cracks were found in the working examples, but comparative examples 1 and 2
Small cracks were observed in the steels of Comparative Example 2, and particularly, those of Comparative Example 2 showed many growths to large cracks.

[Brief description of the drawings]

FIG. 1 is a particle size distribution diagram of a fine component (A ₁ ) and a coarse component (A ₂ ) derived from the volcanic ash of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C04B 14:10 14:14 14:16)

Claims (5)

[Claims] (1) 30 to 50 parts by volume of powder obtained from volcanic ash or lapilli and having a particle size range of less than 2 mm (A ₁ )
And 15 to 25 parts by volume (A ₂ ) of powder having a particle size range of ₂ mm to 4 mm; and 20 parts by volume of cement (B);
(2) The above (A ₁ ) and (A ₂ ) are kneaded together, and the pores of relatively coarse volcanic particles are filled with fine particles of volcanic ash or ground fine particles generated during kneading. (3) The above-mentioned (B)
And a process for the preparation of a waterproof cement formulation, which comprises, if desired, introducing conventional additives and further continuing the kneading so that the cement is tightly adhered to the individual surfaces of the densified volcanic ash grains. 2. The method according to claim 1, wherein 0.05 to 8 parts by volume of humic allophane soil powder is added in step (3). 3. (1) 30 to 50 parts by volume of powder having a particle size range of less than 2 mm (A ₁ ) obtained from volcanic ash or lapilli
And 15 to 25 parts by volume (A2) of powder having a particle size range of ₂ mm to 4 mm; 20 parts by volume of cement (B); and 20 to ₂ parts of water.
Prepare 5 parts by volume (C), (2) grinding occurring during fine particle or empty kneading ash in the pores of the A ₁ and the combined A ₂ empty kneaded to relatively coarse volcanic particles (3) The above-mentioned (B) and, if desired, conventional additives are introduced into the densified kneaded mixture, and the kneaded mixture is further densified to form a densified volcanic ash particle. The cement is allowed to adhere closely to the individual surfaces of (4) and then (C)
(5) A waterproof concrete method comprising removing the air bubbles by placing the obtained mixture in a predetermined position and compacting it. 4. The method according to claim 3, wherein 0.05 to 8 parts by volume of humic allophane soil powder is added in step (2) and / or (3). 5. An aggregate comprising volcanic ash or volcanic rubble, wherein pores are filled with fine volcanic ash particles to close the pore openings to increase the density.