JP3075784B2 - Method for producing concrete molded product by centrifugal force - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a concrete molded product such as a concrete pile by centrifugal force using a glass waste sand material generated by polishing in a glass manufacturing process. It relates to a manufacturing method. 2. Description of the Related Art In the production of concrete piles, fume tubes, and the like, molding by centrifugal compaction is performed. High purity silica powder (SiO ₂
95% by weight or more). [0003] The amount of the above silica powder to be mixed is generally as high as 15 to 35% by weight of cement, and high purity is required and expensive, which is a cause of high cost of concrete products. Had become. In order to produce a high-strength concrete product, compaction by centrifugal force is generally performed. At this time, water contained in the concrete and relatively specific gravity are used. A waste liquid, usually called slag, consisting of small cement paste and fine particles is generated. Since the waste liquid treatment of the slag requires a large amount of treatment cost, it is difficult to suppress or reduce the generation thereof. As a countermeasure, it has heretofore been known to mix an inorganic fine powder or the like (for example, Japanese Patent Publication No. 64-7024,
No. 61-122147). However, the contaminants are expensive, and during high-speed rotation during compaction molding by centrifugal force, the concrete strength of the compact decreases due to separation of the concrete material, and the finished product is not good. have. By the way, in the production of glass, in the polishing step of the glass, fine polishing powder, which is a mixture of ultrafine glass (1 to 30 wt%) containing a large amount of SiO ₂ and fine silica sand, is discharged. abrasive fine powder, generally referred to as a silicate substance mixed material or glass waste sand material, average particle size 1 0 m m, the Blaine value 8500cm ² / g substance
It is. Conventionally, this glass waste sand material has been hardly used, but is simply discarded in an open space or the like in a mud state having a water content of about 30%. Was rare. Since the above-mentioned glass waste sand material contains a large amount of SiO ₂ , it can be used as an admixture, an extender, or a fluidizer for various concrete products and ready-mixed concrete, but is discarded. Waste sand material becomes a clay-like nodule after a short time, so it takes enormous cost to dry and powder it. Because the part hardens rapidly, there are many difficulties such as extremely troublesome handling.Therefore, it is considered impossible to use concrete as an admixture, and it has not yet come to practical use. Was. The present invention has been proposed in view of the above-mentioned conventional circumstances, and effectively utilizes glass waste sand, which has been conventionally dumped as industrial waste, as an admixture for concrete instead of conventional silica powder. To provide a new method of manufacturing concrete molded products by centrifugal force, which enables economical production of high-strength concrete products, hardly generates slag during centrifugal force forming, and improves the product finish. What you want to do. Means for Solving the Problems In order to achieve the above object, the present inventor first studied on the use of abandoned glass waste sand materials in the form of small and powder particles. a result of our, the baby-boom glass waste sand material, after falling disintegrated by utilizing the potential energy, and pelletized to those having a particle diameter of 10mm or less and further crushed by the secondary crushing device, as admixtures of concrete, We have found a way to make it easy and economical to use. Thus, as a result of further research, it is possible to obtain a high-strength concrete product by effectively using a glass waste sand material reduced to 10 mm or less as a concrete admixture in the production of a concrete molded product by centrifugal force. At the same time, it has been possible to propose a method of the present invention that can sufficiently suppress the generation of slag. That is, the method for producing a concrete molded product by centrifugal force according to the present invention uses a specific surface area of 6,000 to 9.0.
A raw material nodule of glass waste sand containing 00 cm ² / g, 80% by weight or more of SiO ₂ is mechanically crushed and reduced to a particle size of 10 mm or less, and is made from Portland cement, fine aggregate, coarse aggregate and water. 5-30% by weight of the above-mentioned small-sized glass waste sand with respect to the cement of the concrete material
After previously kneading with the coarse aggregate, the kneaded material, the remaining concrete material, and 1-2% by weight of the high-performance water reducing agent with respect to the Portland cement are kneaded, and the mixture is mixed with 30G. And compaction with centrifugal force not exceeding. The glass waste sand used in the present invention is:
And the content of SiO ₂ is 80% or more, the specific surface area is 6,000
It is required to have a particle size of 9,000 cm ² / g, preferably 8,000 to 9,000 cm ² / g. This glass waste sand material is generated in the glass polishing process and the like, and is dried and agglomerated to, for example, about 30% moisture in the sun. However, as described above, there are many difficulties in using it as it is, It can be used by mechanically pulverizing it into particles smaller than 10 mm and pulverizing it. The mixing ratio of the above-mentioned small glass waste sand material is 5 to 30% by weight, preferably 10 to 20% by weight, based on the Portland cement in the concrete material. In the present invention, the above-mentioned glass waste sand material is kneaded (premixed) with a part of concrete material in advance, and then the kneaded material (primary kneaded material).
Must be kneaded with the remaining concrete material (mixing). In premixing, the total amount of glass waste sand, 25-75% of the total coarse aggregate, and the total water
Knead with 40-60% water volume. By this pre-mixing, the glass waste sand material which has been reduced in size is refined by the shearing action of the coarse aggregate to increase the bonding force.
The time for this premixing is as short as several minutes. The primary kneaded material kneaded by the premixing is kneaded with the remaining concrete material in the next main mixing step. At that time, the above Portland cement
Adding 1-2% by weight of superplasticizer with respect to preparative kneading. If the mixing ratio of the high-performance water killer is less than the above, the slump value of the concrete becomes extremely low, and it becomes difficult to perform centrifugal force forming. On the other hand, when the mixing ratio of the high-performance water killer is higher than the above, the amount of waste liquid usually generated during centrifugal force molding, which is referred to as slag, increases. This main mixing is performed for several minutes as in the case of the conventional concrete mixing. The centrifugal force forming may be performed by a conventional method. Normally, concrete mixed by this mixing is poured into a mold, and the mold is rotated and compacted by centrifugal force to form
The body is obtained. After that, normal pressure steam curing is performed, and
Then, high-temperature and high-pressure steam curing is further performed. In the centrifugal force forming, generally, the initial speed is about 3 G and the medium speed is about 15 G to shift to high speed, but each speed is performed for a short time within several minutes. In particular, at a high speed, it is necessary to perform the operation in a state not exceeding 30 G, preferably in a range of 25 to 30 G. When the speed is increased to 30 G or more, the amount of slag to be discharged rapidly increases, and the finished product is deteriorated and the strength of the product is reduced. The molded body after the centrifugal force molding is then transferred to curing, where necessary, normal pressure steam curing or high temperature and high pressure steam curing. An embodiment of the method of the present invention will be described below. (1) Materials used are as follows. ○ Cement: ordinary Portland cement (manufactured by Onoda Cement Co., Ltd.) ○ Fine aggregate: sand (specific gravity 2.62) ○ Coarse aggregate: gravel (specific gravity 2.67, maximum dimension 20 mm) ○ High performance water reducing agent: Mighty 150 ( ○ Glass waste sand agent: specific surface area 8540 cm ² / g, specific gravity 2.59 ( manufactured by Central Glass Co., Ltd. ) The main component of the above glass waste sand material is SiO ₂ / 87.3%
_{Al 2 O 3 · 1.9%,} Fe 2 O 3 · 2.8%, CaO
-2.8%, MgO-0.4%. (2) Using the above-mentioned materials, a comparative test was conducted between a concrete according to the present invention using glass waste sand and a concrete according to a conventional method not using glass waste sand (comparative example). Table 1 shows the concrete composition of the concrete of the example of the present invention and that of the comparative example. [Table 1] (3) Concrete Briquetting of Test Specimen Example 1 In the composition shown in Table 1, a total amount of 45 kg of glass waste sand was used, and this was premixed with 572 kg of coarse aggregate and 70 kg of water for 1 minute, and the primary mix was obtained. The kneaded material was mixed with the remaining compounding materials, and mixed for 1 minute. Example 2 In the composition of Table 1, a total amount of 68 kg of glass waste sand was used, and this was premixed with 561 kg of coarse aggregate and 75 kg of water for 1 minute, and this primary kneaded material was mixed with the remaining compounded material, This mixing was performed for one minute. Example 3 In the composition of Table 1, a total amount of 90 kg of glass waste sand material was used, and this was premixed with 554 kg of coarse aggregate and 78 kg of water for 1 minute, and the primary kneaded material was mixed with the remaining compounding material. This mixing was performed for one minute. Comparative Example This mixing was carried out by the conventional method using all the amounts of the ingredients shown in Table 1. (4) Centrifugal force molding In each of the examples and comparative examples,
The sample was placed in a mold for centrifugal force test specimen (outer diameter 20 cm × length 30 cm) and compacted by centrifugal force under the conditions shown in Table 2. [Table 2] (5) Test Results In each of the above Examples and Comparative Examples, after centrifugal molding, two types of curing were performed: normal-pressure steam curing, and normal-pressure steam curing followed by high-temperature and high-pressure steam curing to obtain products. The test was performed. The test results are as shown in Table 3. [Table 3] * 1: Strength after normal pressure steam curing. * 2: The strength of high-temperature and high-pressure steam curing after normal-pressure steam curing. ×: Separation from concrete layer, mortar layer, paste layer is clear. Δ: Not separated but the inner surface is not smooth. □: Not separated, but the inner surface is not a little smooth. ：: There is no separation and the inner surface is smooth. According to the above test results, Example 2 of the present invention
As shown in -1,3-1,4-1,5-1, the compressive strength is 850 kgf / cm ² or more in δAC, and in particular, 1000 kgf / cm ^{2 in} Examples 2-1, 3-1 and 4-1. The values before and after are expressed. Also, regarding the outflow of noro,
In each embodiment, the number was extremely reduced.
It is zero in 4-1 and 5-1. In particular,
In Examples 2-1.3-1 and 4-1, extremely excellent results were obtained with respect to both the compressive strength at δAC and the amount of runoff as compared with the comparative example. As described above, according to the present invention,
To reduce the cost of concrete materials by using glass waste sand materials, which had been discarded as difficult to use in the past, as an admixture instead of high cost-weight cement. Can be expected to have an economic effect. Further, on the other hand, the effect of suppressing the emission of slag is
In addition, since compaction with a smaller rotational force G can be performed compared to compaction with a conventional large rotational force G, noise and vibration of a molding centrifuge can be reduced, and a mold and a centrifuge can be formed. It can be expected to improve the durability of concrete and high strength concrete products can be obtained. It is widely applied to concrete products requiring high strength, such as foundation piles and fume pipes, and has excellent effects.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshiro Hieda 363-3 Higashi Akuragawa, Yokkaichi City, Mie Prefecture (72) Inventor Tsukasa Itaya 12-15, Mitsumachi, Matsuzaka City, Mie Prefecture (56) References JP-A-62-27654 JP, A) JP-A-4-198054 (JP, A) JP-A-4-122605 (JP, A) JP-A-5-31709 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B28B 1/20 C04B 18/16 C04B 18:16

Claims (1)

(57) [Claims] A raw material nodule of glass waste sand containing a specific surface area of 6,000 to 9,000 cm ² / g and a SiO ₂ content of 80% by weight or more is mechanically crushed to a particle size of 10 mm.
In the following, 5-30% by weight of the above-mentioned small glass waste sand material is divided into 5 parts by weight based on the cement of the concrete material consisting of Portland cement, fine aggregate, coarse aggregate and water.
After previously kneading with the coarse aggregate, the kneaded material, the remaining concrete material, and 1-2% by weight of the high-performance water reducing agent based on the kneaded material are kneaded, and the centrifugal force not exceeding 30 G is applied. A method for producing a concrete molded product by centrifugal force, comprising compacting and molding.