JPH0641392B2 - Lightweight concrete product and its manufacturing method, lightweight green concrete and its manufacturing method - Google Patents

Description

The present invention relates to lightweight concrete products such as lightweight concrete blocks and lightweight concrete bricks, a method for producing the same, lightweight ready-mixed concrete (hereinafter referred to as lightweight ready-mixed concrete), and a method for producing the same. Regarding

[Conventional technology]

Natural lightweight aggregates such as natural pumice, lapilli, blast furnace slag, and coal husks are used for conventional lightweight concrete products and lightweight ready-mixed concrete (hereinafter collectively referred to as lightweight concrete products, etc.). However, in recent years, artificial lightweight aggregates made by firing shale, slate, clay, or fly ash at a high temperature have been used because of problems in performance. .

[Problems to be Solved by the Invention]

Lightweight concrete products using the above artificial lightweight aggregate,
While having the great advantage of reducing its own weight and thereby being effective in reducing the cost of reinforcing steel and foundation, the artificial lightweight aggregates described above are expensive in their own right, and thus Lightweight concrete products using such artificial lightweight aggregates are still expensive, and there is a drawback in this respect.

By the way, although a large amount of papermaking sludge is produced in the papermaking industry, since this papermaking sludge generally has a high water content and is not natural, under the present circumstances, it is dried and squeezed and then incinerated. After processing, the incinerated ash is disposed of and is not actively used.

Therefore, the present inventor has conducted extensive studies to effectively utilize the papermaking sludge, and as a result, when the papermaking sludge and the wood chips are burned under specific conditions, the specific gravity is considerably smaller than that of water (0.6 It was found that a porous incinerated ash was obtained, and this porous incinerated ash can be used in the same manner as the above artificial lightweight aggregate.

The present invention was made on the basis of the above findings, and its object is not only to have lightness and excellent strength like the conventional ones, but also to have heat insulation, soundproofing, fireproofing, etc. To obtain a lightweight concrete product or the like having excellent characteristics such as good quality at low cost.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the lightweight concrete product according to the present invention comprises papermaking sludge and wood chips in the range of 750 to 800.
Porous incineration ash obtained by burning at a temperature of ℃, 20 to 30% by weight of cement to the porous incineration ash, 0 to 35% by weight of pea gravel to the porous incineration ash, and porosity It is characterized in that after a kneaded product consisting of 0 to 40% by weight of sand with respect to the incinerated ash and an appropriate amount of water was molded, it was cured and hardened.

Further, the lightweight ready-mixed concrete according to the present invention has a porous incineration ash obtained by burning paper sludge and wood chips at a temperature of 750 to 800 ° C., and 60 to 7 with respect to the porous incineration ash.
150% for 0% by weight cement and porous incineration ash
It is characterized by kneading ~ 250% by weight of sand and an appropriate amount of water.

[Action]

In the lightweight concrete product or the like having the above-mentioned characteristic structure, since the porous incineration ash obtained by burning the paper sludge and the wood chips at a temperature of 750 to 800 ° C. is used as the artificial lightweight aggregate, it is appropriate. In addition to being light and having appropriate strength, it is possible to significantly reduce the cost and to obtain a lightweight concrete product of this kind at low cost.

Further, there is an advantage that the papermaking sludge, which has been treated as an industrial waste in the past, can be effectively used.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a manufacturing process of a lightweight concrete product or the like according to the present invention. In FIG. 1, reference numeral 1 is a combustion treatment device, and a stepped stoker 3 is provided below the inside of a combustion chamber 2. Numerals 4 and 5 denote a papermaking sludge supply hopper and a wood chip supply hopper formed on the upstream side of the stoker 2, respectively. 6 is an ash discharging conveyor provided on the downstream side of the stoker 3, 7 is an ash storage area for storing the porous incinerated ash 8 carried out by the conveyor 6 (this porous incinerated ash 8 will be described later), 9 is a stoker Ridling conveyor 10 provided below 3 is a burner. 11 is a combustion chamber 2
Is a dust collector, 13 is a draft fan, and 14 is a wet scrubber.

Reference numerals 15 and 16 denote papermaking sludge and wood chips stored in storage tanks 17 and 18, respectively. As the papermaking sludge 15, it is usually preferable to use one having an ash content of 25% or less. The papermaking sludge 15 having an ash content of 25% or less can be burned in the stoker 3 by drying or squeezing to reduce the water content to about 52%. Further, as the wood chips 16, it is possible to use waste wood chips, and it is usually preferable to use those having a size of about 5 to 50 mm. It is preferable that the wood chips 16 also have a water content of about 45% or less so that the wood chips 16 self-combust in the stoker 3. The water content of the papermaking sludge 15 and the wood chips 16 can be adjusted by a conventionally known method, and it is preferable to adjust the water content to an appropriate amount before supplying the papermaking sludge supply hopper 4 and the wood chip supply hopper 5. preferable.

The papermaking sludge 15 and the wood chips 16 are put into the papermaking sludge supply hopper 4 and the wood chip supply hopper 5 by using an appropriate means such as a hoist crane, and are supplied to the stoker 3 after being adjusted to predetermined supply amounts. It The supply state of the papermaking sludge 15 and the wood chips 16 at this time is preferably such that the papermaking sludge 15 is in the lower layer and the wood chips 16 are in the upper layer. Complete burning with 16. The paper sludge 15 and the wood chips 16 are supplied in different amounts depending on their respective properties.
The weight ratio of the wood chips 16 to the wood chips 16 is preferably papermaking sludge 15: wood chips 16 = 70 to 80:30 to 20, and the ratio of the layer thicknesses of the two supplied on the stoker 3 is: Wood chip 16: Paper sludge 15 = 1: 1.05-
It should be set to 1.15.

Although not shown in detail in the combustion chamber 2, the primary air, the secondary air, and the recirculation gas are provided by a primary forced draft fan, a secondary forced draft fan, an induction draft fan 13, a gas recirculation draft fan, and the like. Are configured to be supplied respectively.
Further, the combustion chamber 2 is provided with a temperature detection sensor, and the combustion temperature of the papermaking sludge 15 and the wood chips 16 on the stoker 3 is controlled to be 750 to 800 ° C. The entire wall surface of the combustion chamber 2 has a water-cooled wall structure to absorb heat.

Paper sludge 15 and wood chips 1 supplied on the stoker 3.
6 is gradually lowered by the reciprocal differential of the grate of the fire bed, is dried by the air and gas, is ignited by the burner 10 and burns. The combustion temperature at this time is 800
If the temperature exceeds ℃, the ash (sludge) is melted, so that the porous incinerated ash 8 cannot be obtained, and if the temperature is lower than 750 ° C., the unburned content increases and the desired porous incinerated ash 8 cannot be obtained.

The porous incineration ash 8 generated by the burning of the paper sludge 15 and the wood chips 16 on the stoker 3 in this manner is carried out of the combustion chamber 2 by the ashing conveyor 6 and stored in the ash storage area 7. The porous incinerated ash 8 is cooled and then crushed to have a predetermined particle size (10 mm or less). The porous incinerated ash 8 has a specific gravity of about 0.
It is as light as 6 and has excellent heat insulation, soundproofing and fireproofing.

Next, a method for obtaining a lightweight concrete product such as a lightweight concrete block or a lightweight concrete brick using the porous incinerated ash 8 obtained as described above will be described. As shown in the lower part of FIG. A predetermined amount of porous incinerated ash 8, cement 20, bean gravel 21, sand 22 and water 23 are charged therein as materials, and these are sufficiently kneaded, and then this kneaded product is supplied to a predetermined molding machine 24. Then
For example, extrusion molding, taking out from the molding machine 24, and
Lightweight concrete block 2 as a lightweight concrete product by curing as specified in IS A5406 (Japanese Industrial Standard, hollow concrete block)
5 can be obtained.

The table below shows the blending amount (unit: kg) of each of the above materials in the lightweight concrete block 25 manufactured according to the present invention.

Lightweight concrete block 25 based on the composition of I to V above
Indicates that the compressive strength after 4 weeks and the compressive strength after 2 hours of water immersion are both 40 kg / cm ² or more, and have cleared the compressive strength of the type A block specified in JIS, and are used as type A block. can do.

Then, when the inventor changed the compounding amount of each material and conducted the same test, the preferable compounding ratio is as follows. That is, porous incineration ash 8, 20 to 30% by weight of cement 20 with respect to porous incineration ash 8, 0 to 35% by weight of pea gravel 21 with respect to porous incineration ash 8, and porous incineration ash It is sufficient to knead 0 to 40% by weight of sand 22 with respect to 8 and an appropriate amount of water 23.

Here, if the compounding weight of the cement 20 to the porous incineration ash 8 is less than 20%, the desired strength cannot be obtained, and
If the weight exceeds 30%, cracks are likely to occur and the cost increases. Then, when the blending weight of the soybean gravel 21 with respect to the porous incinerated ash 8 exceeds 35%, the weight increases accordingly. Further, if the blending weight of the sand 22 with respect to the porous incinerated ash 8 exceeds 40%, the cost will increase.

By the way, the porous incineration ash 8 can be used not only in a lightweight concrete product but also as an artificial lightweight aggregate in lightweight green concrete. That is, porous incineration ash 8, 60 to 70% by weight of cement 20 with respect to porous incineration ash 8, and 150 to 250 with respect to porous incineration ash 8
It suffices to sufficiently knead the sand 22 of weight% and an appropriate amount of water. In that case, a very small amount of Pozzolith 70 (trade name) may be added as an admixture. In FIG. 1, reference numeral 26 indicates a lightweight green concrete.

Here, if the blending weight of the cement 20 with respect to the porous incinerated ash 8 is less than 60%, the desired strength cannot be obtained, and
If the weight exceeds 70%, cracks are likely to occur and the cost increases. If the blending weight of the sand 22 with respect to the porous incinerated ash 8 is less than 150%, the desired strength cannot be obtained, and if the weight exceeds 250%, the cost increases.

The lightweight green concrete 26 having the above mixing ratio can also be used in the same manner as the conventional lightweight green concrete.

The present invention is not limited to the above embodiment, and for example, the combustion processing device 1 may have a structure other than the above. Further, it goes without saying that the lightweight concrete product 25 such as the lightweight concrete block or the lightweight concrete brick may be manufactured by a method other than the extrusion molding.

〔The invention's effect〕

As described above, according to the present invention, since the porous incineration ash obtained by burning paper sludge and wood chips at a temperature of 750 to 800 ° C. is used as the artificial lightweight aggregate, an appropriate light weight is used. Thus, it is possible to easily and inexpensively obtain a lightweight concrete product having appropriate strength and excellent heat insulation, soundproofing, and fireproofing.

Further, according to the present invention, there is an advantage that the papermaking sludge, which has been conventionally treated as a troublesome industrial waste, can be effectively used, and it has an extremely great effect from a national standpoint.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a manufacturing process of a lightweight concrete product or the like according to the present invention. 8 ... Porous incineration ash, 15 ... Paper sludge, 16 ... Wood chips, 20 ... Cement, 21 ... Bean gravel, 22 ...
Sand, 23 ... Water, 25 ... Lightweight concrete products, 26
...... Lightweight concrete.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical indication location C04B 38/08 B (72) Inventor Toshio Mochizuki 2 76-2 Tamachi, Shizuoka City, Shizuoka Prefecture Mochizuki Block Industry Co., Ltd. (72) Inventor Watanabe ▲ Ei Oji 655-2 Mukaimoto-cho, Shimada City, Shizuoka Prefecture 72 (72) Inventor Misao Sakai 1364-3 Nakashinda, Yaizu City, Shizuoka Prefecture (72) 590 Takao, Takayama, Tsuyama City, Okayama Prefecture Address No. 1 in Japan Vegetation Co., Ltd. (56) Reference JP-A-50-46729 (JP, A) JP-A-1-64077 (JP, A)

Claims (4)

[Claims] 1. Paper-making sludge and wood chips 750-800
Porous incineration ash obtained by burning at a temperature of ℃, 20 to 30% by weight of cement to the porous incineration ash, 0 to 35% by weight of pea gravel to the porous incineration ash, and porosity A lightweight concrete product characterized by being cured and cured after molding a kneaded product composed of 0 to 40% by weight of sand with respect to incinerated ash and an appropriate amount of water. 2. Paper-making sludge and wood chips 750-800
Porous incineration ash obtained by burning at a temperature of ℃, 20 to 30% by weight of cement to the porous incineration ash, 0 to 35% by weight of pea gravel to the porous incineration ash, and porosity A method for producing a lightweight concrete product, which comprises kneading 0 to 40% by weight of sand with respect to incinerated ash and an appropriate amount of water, molding the kneaded product, and thereafter curing and curing the kneaded product. 3. Paper-making sludge and wood chips 750-800
Porous incineration ash obtained by burning at a temperature of ℃, 60 to 70 wt% cement to porous incineration ash, 150 to 250 wt% sand to porous incineration ash, and an appropriate amount of water Lightweight concrete made by kneading and. 4. Paper-making sludge and wood chips 750-800
Porous incineration ash obtained by burning at a temperature of ℃, 60 to 70 wt% cement to porous incineration ash, 150 to 250 wt% sand to porous incineration ash, and an appropriate amount of water A method for producing lightweight ready-mixed concrete, which comprises kneading and.