JPH06293547A - Wood containing cement hardened body - Google Patents

Abstract

PURPOSE:To provide a lightweight cement composition having improved strength and processability by adding minute fragments obtained by crushing a wood containing cement hardened body which is hardened by hydrating it, to the composition. CONSTITUTION:The minute fragments of the wood containing cement hardened body such as a cement chip board disposed as waste are obtained by coarsely crushing the cement hardened body into coarse fragments having about 150mm maximum fragment length by using a jaw crusher, etc., and then crushing the resulting coarse fragments into fine fragments having 0.1 to 3mm particle size by using a hammer mill, etc. Thereafter the resulting fine fragments are fed into e.g. the upper coarse-mesh sieve of a set of two sieves comprising the upper sieve and a lower fine-mesh sieve to obtain the minute fragments consisting essentially of a wood material which are screened and remain on the lower fine-mesh sieve. 10 to 100 pts.wt. of the minute fragments and 100 pts.wt. of simple or blended cement such as commercial ordinary portland cement, blast-furnace cement, are mixed with each other while adding adequate amounts of water and other necessary extenders and additives, etc., to obtain a mixed composition. The mixed composition is extruded to form moldings or allowed to flow into molds to form moldings and then the moldings are cured in a humidified atmosphere and thereafter subjected to hydration reaction by using the autoclave-treatment to obtain the hardened bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hardened wood-containing cement, and more particularly to a hardened wood-containing cement that can utilize industrial waste.

[0002]

2. Description of the Related Art Conventionally, a method of adding wood powder, wood chips or the like as a bone agent has been carried out in order to reduce the weight of a hardened cement product and improve its strength and workability. However, in this method, hardening inhibitors such as lignin sulfonate, oxycarboxylic acid and saccharide derivatives contained in wood and calcium ions on the surface of the cement powder form a complex or a chelate compound, which is formed on the surface of the cement powder. There is a problem that it adheres and hinders contact with water necessary for the hydration reaction, and delays hydration hardening.

Therefore, a curing accelerator (calcium chloride,
Although sodium chloride, carbonates, sulfates, etc.) have also been added, this method has a problem that the strength is remarkably reduced with the passage of time even if the desired strength is obtained immediately after the production. .

On the other hand, it is possible to reduce the amount of wood added in order to reduce the adverse effects of wood, but the amount of wood added is 1
If it is 0% by weight or less, there is a problem that sufficient effects cannot be obtained in weight reduction and improvement in workability.

In view of the above problems, it is an object of the present invention to provide a light-weight hardened cement containing wood, which has high strength and excellent workability.

[0006]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventor has conducted earnest research and as a result, when wood and cement are mixed and hydrated and hardened, the hardening inhibitory substance of the wood becomes hydration water. It was found out that it does not cause curing inhibition again, and based on this finding, the present invention was completed.

[0007] The gist of the present invention is a hardened wood-containing cement, which is characterized in that the hardened wood-containing cement is composed of fine fragments obtained by crushing a hydrated hardened hardened wood-containing cement and cement.

Examples of the hydrated-hardened wood-containing cement hardened product include discarded pieces of wood chip cement plates (defective processed products, damaged products, processed scraps, etc.). When such a waste product that is industrial waste is used, resources can be effectively used, and therefore there is an advantage that not only the pollution problem can be solved but also the production can be performed at low cost.

The method of crushing can be arbitrarily selected from existing methods. For example, a method of crushing to a maximum length of about 150 mm with a crusher such as a jaw crusher and further finely crushing using a hammer mill or the like. Is mentioned.

The size of the fine fragments can be arbitrarily selected as required, but the particle size is preferably 0.1 mm or more and 3 mm or less, and particularly preferably 0.1 mm or more and 1 mm or less. Particle size is 0.
This is because if it is less than 1 mm, the desired strength cannot be ensured, and if it exceeds 3 mm, uniform mixing cannot be achieved and strength deterioration occurs.

As a method for selecting the minute fragments having a desired particle size from the fragments, for example, 2 particles having different mesh openings can be selected.
There is a method in which individual sieves are piled up, the above-mentioned crushed pieces are put into a coarse upper sieve and sieved, and only the fine crushed pieces remaining in the fine lower meshed sieve are collected and selected.

[0012] Since the hydration-hardened cement of the wood chip cement board is fragile, when the wood-containing cement hardened product is finely crushed, for example, to a particle size of about 3 mm, it is simultaneously finely crushed, and most of them are open eyes. Pass through a fine screen, for example, a screen with an opening of 0.1 mm.
Therefore, it is considered that the hydration-hardened cement remaining in the fine mesh was not adhered or crushed to the fine fragments, and the total amount thereof was about 1% of the fine fragments. As a result, it can be considered that most of the fine fragments left on the sieve having an opening of 0.1 mm are made of wood.

The cement to be mixed with the fine crushed pieces is not particularly limited, and commercially available cements such as ordinary Portland cement, blast furnace cement and silica cement can be used alone or in combination. The mixing ratio of the cement and the fine fragments is preferably 10 to 100 parts by weight with respect to 100 parts by weight of the cement. This is because if it is less than 10 parts by weight, it is not possible to expect a decrease in specific gravity, improvement in workability and impact resistance, and if it exceeds 100 parts by weight, the effect of cement as a binder is small and the strength is lowered. .

Then, cement, water, and necessary extenders and additives are added to the finely divided pieces in appropriate amounts and kneaded to obtain a kneaded product, which is extruded and molded, or poured into a desired mold. After molding and wet curing, a desired wood-containing cement hardened product is obtained by hydrating and curing in an autoclave.

The curing and curing method is not limited to the above-mentioned method and can be arbitrarily selected from the existing methods. For example, the molded body is wrapped in a sheet and sealed at room temperature, or a constant temperature is applied. It can be wet-cured in a constant-humidity bath.

Examples of the necessary extender include fine powder of cement obtained by crushing hydration-hardened wood cement board. The hydration-hardened cement in the fine powder cannot be used as a binder because the hydration reaction has already been completed, but if it is used as an extender, production cost can be reduced and resources can be effectively used. . However, if added in a large amount, it causes strength deterioration. Therefore, it is preferable that the addition amount of the fine powder of hydration-hardened cement is 100 parts by weight or less relative to 100 parts by weight of fine crushed pieces. 1
This is because if the amount exceeds 00 parts by weight, the required strength cannot be secured.

The necessary additives include, for example, viscosity modifiers such as methyl cellulose for enhancing moldability, and further, workability and workability such as pearlite are improved, and A lightweight aggregate for further weight reduction is mentioned.

[0018]

【Example】

(Example 1) A wood chip cement board was roughly crushed with a jaw crusher to a maximum length of about 150 mm, and further finely crushed with a hammer mill to obtain crushed pieces. Then open your eyes 0.1
A sieve having an opening of 0.3 mm was placed on a sieve of mm, the sieve was vibrated by a vibrating sieve machine, and the crushed pieces were put into an upper sieve and sieved. The weight ratio of the fine crushed particles having a particle size of 0.1 to 0.3 mm remaining on the sieve having an opening of 0.1 mm and the fine powder having passed through the sieve having a diameter of 0.1 mm was about 5: 4. It was

Then, the finely divided pieces and the fine powder as the extender were mixed in a weight ratio of 80:20 to obtain a mixture having a specific gravity of 1.0.

Cement, methylcellulose and water were added to the obtained mixture in the proportions shown in Table 1 and kneaded to obtain a kneaded product. The kneaded product was extruded with a width of 210 mm, a length of 3000 mm and a thickness of 21 mm. It was formed into a plate.

Then, after moisturizing and curing in a thermo-hygrostat at a temperature of 60 ° C. and a humidity of 98% for about 1 week, the temperature is kept at 150 ° C. for 8 hours.
Autoclave curing was performed for a period of time to obtain a plate-shaped sample.

(Example 2) As shown in Table 1, except that the compounding ratio was different from that of Example 1, other than the above Example 1
A sample was obtained by the same treatment as described above.

Example 3 A sample was obtained by the same procedure as in Example 1 except that the compounding ratio was changed and the casting method was adopted instead of extrusion molding. The casting method in this example refers to a method of molding a kneaded product having the above-mentioned mixing ratio with a mold.

Example 4 A sample was obtained by the same procedure as in Example 3 except that the compounding ratio was different from that in Example 3 as shown in Table 1.

Comparative Example 1 A sample was obtained by the same procedure as in Example 1 except that wood powder was used instead of the mixture and the mixing ratio was as shown in Table 1. . The wood powder (trade name: wood powder) has a specific gravity of 0.
8, the particle size of 0.3 to 0.5 mm was used.

Comparative Example 2 A sample was obtained by the same procedure as in Comparative Example 1 except that the compounding ratio was different from that of Comparative Example 1 as shown in Table 1.

Comparative Example 3 A sample was prepared in the same manner as in Example 3 except that wood flour was used in place of the mixture, and the mixture was added as shown in Table 1 without adding methylcellulose. Got

Comparative Example 4 A sample was obtained by the same procedure as in Comparative Example 3 except that the compounding ratio was different from that in Comparative Example 3 as shown in Table 1.

[0029]

[Table 1]

Then, each sample was subjected to various tests, and the measurement results are shown in Table 2. However, Comparative Examples 2 and 4 were broken by just lifting them by hand and could not be measured. It is considered that this is because the curing inhibition of the wood flour caused the curing inhibition.

[Table 2]

Examples 1 and 3 in Table 2 and Comparative Example 1
Comparing 3 and 3, respectively, it was found that Examples 1 and 3 had a smaller specific gravity and were lighter than Comparative Examples 1 and 3.

Further, it was found that Examples 1 and 3 were larger in bending strength and smaller in bending Young's modulus than Comparative Examples 1 and 3, so that they were hard to break and also had a large deflection before breaking and were hard to crack.

Next, when a nailing test was conducted on each sample, in the cases of Comparative Examples 1 and 3, the nails were often bent in the middle even if they were nailed with screw nails. Was easy to nail and hard to pull out.

Further, a cutting test was carried out in which a cutting saw for cutting the outer wall was used. In the case of Comparative Examples 1 and 3, when the sample was cut, the cutting blade was immediately worn out and could not be cut. In the cases of and 3, even when the sample was cut, almost no wear of the cutting edge was observed.

From the above test results, it was found that Examples 1 and 3 were lighter than Comparative Examples 1 and 3 and were excellent in strength, toughness and workability. Therefore, it is considered that Examples 1 and 3 are more suitable as building materials than Comparative Examples 1 and 3.

[0036]

As is apparent from the above description, the hardened wood-containing cement according to the present invention comprises cement and fine crushed particles obtained by crushing a hydrated-hardened hardened wood-containing cement. . Since the hardening inhibitor existing in the wood of the minute pieces has already been eluted in the hydration water, the wood does not hinder the hardening of the cement. For this reason, since the strength does not decrease as in the conventional example, a hardened wood-containing cement is obtained, which is stronger than the conventional example. Furthermore, since most of the fine crushed particles are wood materials in which the hardening inhibiting material is eluted, a large amount can be added as compared with the unused wood powder and the like. Therefore, according to the present invention, it is possible to obtain a hardened wood-containing cement that has a workability equal to or higher than that of the conventional example and is lighter than the conventional example. In particular, if the hydrated and hardened wood-containing cement hardened product is a discarded product such as a defective piece of wood cement board, a damaged product, etc., resources can be effectively utilized, and the occurrence of pollution problems can be prevented. This has the effect of reducing production costs.

Claims (2)

[Claims] 1. A hardened wood-containing cement, characterized by comprising fine fragments obtained by crushing a hydrated hardened hardened wood-containing cement, and cement. 2. The hardened wood-containing cement according to claim 1, wherein the maximum particle size of the fine fragments is 3 mm or less.