JPH0211543B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention involves adding a small amount of hydraulic binder to inorganic powder waste and molding it into civil engineering construction materials such as building blocks, road bases, backfilling of structures, and embankment frames. The invention relates to a method for manufacturing a product or constructing a cured product. (Prior art) Conventionally, stone powder generated during the production of crushed sand, waste fine sand generated during silica sand refining, reducing group slag powder generated from electric steelmaking furnaces, and cement hydrate generated from wastewater treatment at ready-mixed concrete factories. Sludge (hereinafter referred to as ready-mixed concrete drainage sludge), gypsum and fly ash generated from the flue gas treatment of coal-fired power plants are produced in huge amounts, but their utility value is still low today, and there is no effective way to recycle them. Due to the lack of technology, most of the materials, except for a few, are currently being disposed of. On the other hand, as a method of reusing these inorganic powder wastes in construction work where a large amount can be used, a method is to add a binder such as cement to these inorganic powder wastes and pour it into a fluid state to solidify it. , a method of mixing with a small amount of water and compacting and solidifying the mixture using a compaction machine, and a method of manufacturing granules using a granulator, but the fluidized solidified product and compacted solidified product are not sufficient. A large amount of binder is required to obtain strength characteristics, and granulated materials are inferior in grain shape and size compared to crushed stone. On the other hand, attempts have also been made to sinter or melt and solidify these inorganic powders by firing, and to use the granules and crushed materials as artificial crushed stone as a substitute for crushed stone. However, in order to obtain high strength, this method requires the use of a large amount of binder such as cement, and consumes a large amount of thermal energy for sintering, so it is significantly more expensive than using crushed stone. Because they can only be used for purposes with low added value, they can only be recycled, which is extremely uneconomical. In addition, when a mixture of these inorganic powder wastes with an appropriate amount of binder and water is spread as a road base and compacted using a normal paving machine, if the water content of the mixture is low, the particles in the mixture will There is a lack of adhesion between the particles, and even if the rolling energy is increased, little compaction effect can be obtained.Also, as the rolling energy is increased, the plasticity increases, but with ordinary paving machines, it becomes difficult to roll due to so-called kneading. Whether the moisture content is low or high, on-site compaction using regular paving machines is impossible.
For this reason, reuse such as using inorganic powder waste as the main material for paving roadbeds has not been put into practical use, and it is hoped that a technology that is simple, economical, and has high reuse value will emerge. was. (Problems to be Solved by the Invention) Therefore, the present invention aims to utilize a small amount of hydraulic binder and a simple processing process in the recycling technology of inorganic powder waste, which has conventionally been difficult to dispose of as industrial waste. This was developed with the aim of improving the strength characteristics and economic efficiency of the inorganic powder waste. It is something. (Means for solving the problem) In other words, the method of the present invention is to create a mixture (hereinafter referred to as a primary mixture) in which a small amount of hydraulic binder is added to inorganic powder waste, and a small amount of water is added to the mixture. The hardened product (hereinafter referred to as "hardened product") is molded into an appropriate shape by extrusion, pressure, etc., and the hydration reaction progresses through subsequent curing, and the compressive strength reaches several tens of kgf/ ^cm2 . The mixture (referred to as primary hardened material) is crushed to an appropriate particle size (for example, 30 mm or less), and several to several tens of parts by weight of the mixture before molding is added to 100 parts by weight of the crushed material, and the mixture after kneading (referred to as (called secondary mixture)
The present invention relates to a method for manufacturing a hydraulic cured body, which is characterized by compacting, molding, and curing to produce a cured body (hereinafter referred to as a secondary cured body) that generates hardening strength. The inorganic powder wastes mentioned here include rock powder (waste from crushing factories, etc.), fly ash (waste from thermal power plants), raw concrete drainage sludge consisting of cement hydrate, silica sand waste (silica sand for glass, etc.)
Water sieve waste from the refining of frog's eye clay, etc.), mold waste sand, mine slag, etc. Hydraulic binders that have binding strength themselves include ordinary Portland cement, blast furnace cement, fly ash cement, There are silica cements, etc. The amount of water added here is to provide plasticity during molding, so the amount added must be at least such that molding is possible and water does not ooze out during molding. For 100 parts of powder weight
Preferably, it is 20 to 30 parts by weight. In addition, the compaction referred to here refers to compaction machines such as macadam rollers, pneumatic tire rollers, vibrating rollers, etc. that can be used to lay pressure molding machines on the pavement road bed in the production of molded products. . Furthermore, if necessary, chemical admixtures for cement concrete may be used for the purpose of accelerating setting, hardening, or delaying setting when mixing the primary mixture or secondary mixture. Hereinafter, the method of the present invention will be explained in more detail with reference to Examples. However, the method of the present invention is not limited to the examples shown below. (Example) Inorganic powder waste, that is, 90% of fly ash, which is waste from thermal power plants shown in Table 1, is used here.
Water (water content: 35%) is added to a mixture of 80 parts by weight and 10 to 20 parts by weight of hydraulic cement, in this case ordinary Portland cement, mixed uniformly in a kneader, and then extruded. After molding into a cylindrical shape with a diameter of 10 cm and a length of about ²⁰ cm using a molding machine, it is cured to become a primary hardened product. shown in Table 2).
It was crushed so that the maximum particle size was 25 mm or less.
Then, the primary mixture before molding was added to 100 parts by weight of this crushed material, mixed uniformly, compacted, molded, and cured to obtain a secondary cured product. The results are shown in Table-3.

【table】

[Table] * Based on the unconfined compression test method for cement-stabilized soil in Appendix 4-7 of the Japan Road Association's Asphalt Pavement Guidelines.

[Table] * Appendix 4-7 of the Japan Road Association's asphalt pavement guidelines for cement-stabilized soil
The uniaxial compression test method was used.
(Effects of the Invention) As is clear from the above, the method of the present invention for obtaining a solidified body of inorganic powder waste using a small amount of hydraulic binder can Not only does it have a remarkable effect on reuse, but it also has an excellent effect on saving labor and energy in the process of recycling.

Claims (1)

[Claims] 1 Add a small amount of water to a small amount of hydraulic binder added to inorganic powder waste, mix it uniformly, and then mold it into an appropriate shape by extrusion, pressurization, etc., and then cure it to shape it. The strength of objects is tens of
When the particle size reaches Kgf/cm ² or more, the cured product is crushed to an appropriate particle size, and several to several tens of parts by weight of the uncured mixture before molding is added to 100 parts by weight of the crushed product, mixed and compacted. A method for producing a hydraulically cured body, which comprises hardening, molding, and curing to obtain a homogeneous secondary cured body.