JPH10219246A - Organic solidification material for poor ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject material by including a slag composite with a specific composition obtained through incinerating and fusing various kinds of waste products, etc., to make into slag and to utilize the slag composite effectively. SOLUTION: This slag composite is effectively utilized by blending it with Portland cement, blast furnace slag and gypsum, etc., as a component of an organic solidification material for poor ground. The above slag composite comprises (A) 0-37wt.% CaO, (B) 23-90wt.% SiO2 , (C) 0-40wt.% Al2 O3 , (D) 0.1-50wt.% at least one kind selected from a group of iron oxides, alkalis, phosphorus, titanium oxides, manganese oxides and magnesium oxides and/or (E) 0.1-10wt.% halogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic soft ground solidifying material used for improving soft organic ground such as peat, and more particularly to a slag composition obtained by incinerating and melting various wastes into slag. Regarding what to use.

[0002]

2. Description of the Related Art Especially in large cities, there are various problems such as disposal of sewage sludge and municipal solid waste and construction waste materials, etc. There are various problems such as securing final disposal sites, and recycling including recycling. There are many active research studies. Under such circumstances, sewage sludge incineration ash and municipal refuse incineration ash, incinerated to reduce the volume of sewage sludge and municipal waste,
Furthermore, local governments, equipment manufacturers, and the like are developing effective utilization technologies for slag that has been melt-processed to further reduce the volume thereof. However, although its use has begun to be used as an aggregate for roadbed materials and blocks, and as a raw material for tiles and bricks, the amount of its use is insignificant, and it is limited due to technical and price restrictions, distribution problems, etc. However, it is not at the stage where it is still actively being used effectively, and the fact is that the company is worried about its processing.

[0003] Organic soft ground such as peat is usually
Because the water content is extremely large and there is almost no bearing capacity,
Improvements have been made to replace the surface with high quality soil. However, the improvement by this replacement method is rarely due to the existence of good quality soil near this type of ground.
In addition to problems such as securing high quality soil and transportation costs,
In some cases, a satisfactory bearing capacity cannot be obtained only by improving the surface layer of the ground. Therefore, methods of improving the surface layer by mixing cement with the organic soft ground, and injecting cement milk into the deep organic soft ground have been tried, but the hardening of the cement in the organic soft ground has been attempted. A large amount of lignin-like substances represented by humic acid, fulvic acid, and the like, which have an adverse effect, are not obtained, and a satisfactory improvement effect cannot be obtained.

Therefore, as a solidifying material for organic soft ground, a cement-blast furnace slag-gypsum-based material as disclosed in Japanese Patent Publication No. 26598/1986 is widely used. Further, recently, in order to further improve the improvement effect, “solidified material using hydraulic fine powder” disclosed in JP-A-63-199283 and JP-A-60-137496 have been disclosed.
For example, a method of pulverizing cement, blast-furnace slag, and gypsum to increase the reaction activity of the solidified material itself, such as “solidified material for sludge” disclosed in Japanese Patent Application Laid-Open No. H10-260, has been proposed.

[0005]

Although the incineration sewage sludge and refuse incineration ash, as well as those obtained by melting and converting them into slag, have been studied for their effective use for many years, they are still very effective. At present, it is not being used. For example, regarding sewage sludge, the Ministry of Construction has been conducting research on the recycling of sewage sludge since 1975, and subsidizes facilities that can effectively use sludge in order to promote their effective use. Furthermore, Showa 63
From fiscal year, we have been conducting a sewage sludge resource utilization model project, which includes the active use of sludge products (roadbed materials, soil improvement materials, etc.) in sewage construction projects. Regarding the solidification material for organic soft ground, in order to enhance the reaction activity, the method of pulverization is also expensive and involves the problems of technical pulverization. Is desired. The present invention has been made in view of such a point, and various kinds of wastes such as sewage sludge incineration, garbage incineration, and industrial waste are used as raw materials, and clay, limestone, etc. are added thereto as necessary. A slag composition of a specific composition whose components are adjusted and melted and quenched at a high temperature is intended to be used as a solidifying material for organic soft ground.

[0006]

Means for Solving the Problems The present inventors blend a slag composition of a specific composition obtained by melting sewage sludge incineration ash or refuse incineration ash with an alkali stimulant in the same manner as blast furnace slag. Thus, it exhibits good hydraulic properties and has excellent curability, so that it can be used effectively as a solidifying material for organic soft ground.

That is, the present invention provides:
37 wt%, SiO ₂ minutes 23-90 wt% and Al ₂ O ₃
One to two or more components selected from iron oxide, alkali, phosphorus, titanium oxide, manganese oxide and magnesium oxide in an amount of 0.1 to 50% by weight and / or a halogen content of 0 to 40% by weight. An organic soft ground solidifying material containing 0.1 to 10% by weight of a slag composition. The above-mentioned organic ground improving material of the present invention comprises (2) the above-mentioned slag composition,
Includes organic soft ground solidifying material containing Portland cement, blast furnace slag, and gypsum.

Further, the organic soil improving material of the present invention comprises:
(3) The slag composition is made from various wastes such as sewage sludge incineration, garbage incineration, and industrial waste as raw materials, and if necessary, components are adjusted with clay and limestone, melted and quenched at a high temperature,
An organic soft ground solidifying material pulverized to a specific surface area of at least 3,500 cm ² / g, (4) the slag composition, Portland cement, blast furnace slag, and gypsum are respectively 1 to 80% by weight, 5 to 50% by weight. % By weight, 0-8
0% by weight and 5 to 30% by weight of an organic soft ground solidifying material.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The slag composition used for the solidifying material for organic soft ground according to the present invention has a CaO content of 0 to 37% by weight,
one or two selected from iron oxide, alkali, phosphorus, titanium oxide, manganese oxide and magnesium oxide in an iO ₂ content of 23 to 90% by weight and an Al ₂ O ₃ content of 0 to 40% by weight;
A slag composition obtained by melting at a high temperature and quenching the one or more components adjusted to be a chemical component having 0.1 to 50% by weight or / and a halogen content of 0.1 to 10% by weight. is there. Here, various raw materials may be used by mixing commercially available materials, but sewage sludge incineration ash, garbage incineration ash, industrial waste, and the like have chemical components within the above range even when used directly. Most of them are used, and it is more preferable to use them in terms of economy and effective use of unused resources.

The content of SiO ₂ in the slag composition is as follows:
When the amount is small, it becomes difficult to form a slag, and when the amount is large, the slag forming temperature becomes high.
% Is more preferred. If the content of CaO is large, other components are relatively reduced and it becomes difficult to vitrify. Therefore, 0 to 37% by weight is preferable, and 1 to 35% by weight is more preferable. Further, the Al ₂ O ₃ content is 0 to 40% by weight because the slag-forming temperature increases when the content is large, but 1 to 40% by weight, especially 1%.
0-30% by weight is preferred. From the viewpoint of strength development, the weight ratio of CaO component / SiO _{2 component} is preferably 1.3 or less.

Further, one or more kinds (residual elements) selected from iron oxide, alkali, phosphorus, titanium oxide, manganese oxide and magnesium oxide, and halogen are:
It is effective for slag activation, but if it is too much, the strength development becomes poor. Therefore, the residual element content is 0.1 to 50% by weight (as oxide) and the halogen content is 0.1 to 10% by weight. Preferably, these may be contained alone or both.

The above-mentioned slag composition shows good hydraulic properties by blending with an alkaline stimulant such as Portland cement, even though the CaO content is 37% by weight or less, and has excellent strength development. In addition, since it contains the Al ₂ O ₃ component, in the hydration process, gypsum is added to supply SO ₃ , and ettringite, which is a fibrous hydrate having a very large amount of crystallization water, is formed. easy.

[0013] When a cement-based material is used for an organic soft ground as in the past, the organic component in the ground absorbs and traps Ca ions necessary for the generation of CSH, so that C-
There is a problem that the generation of SH is remarkably hindered and the solidification / improvement is hindered.

The organic soft ground solidifying material of the present invention is a material which is easy to produce ettringite by adding a hydraulically hardened slag composition using an alkali stimulant. This ettringite contains a very large amount of water as water of crystallization and produces fibrous crystals. By the generation of ettringite, water in the ground is taken in as crystallization water, the water content ratio is reduced, and the fibrous crystals have a function of densifying the structure. In addition, the ettringite formation reaction proceeds very quickly, has an effect on strength development in the initial stage, and has the property of incorporating organic components in the ground into its crystals. It is promoted and the development of long-term strength is also improved.

In the solidifying material for organic soft ground as described above, the compounding ratio is 1 to 80% by weight of the slag composition, 5 to 50% by weight of Portland cement, and 0 to 80% of blast furnace slag.
% By weight and 5 to 30% by weight of gypsum are preferred.

The fineness of the slag composition, Portland cement, blast furnace slag and gypsum is preferably adjusted by individual grinding or mixed grinding of two or more types.
Further, it is preferable that the degree of fineness is 3500 cm ² / g or more in a state where each pulverized material or a mixture of two or more types is mixed.

In the present invention, the blast furnace slag includes blast furnace water, blast furnace, converter, electric furnace, blast furnace crushed stone, and the like. One or more blast furnace slags can be used as long as the effects of the present invention are not impaired. In addition, it is preferable that the blast furnace slag is contained at least in a small amount during the compounding.

In the present invention, one or more of dihydrate gypsum, hemihydrate gypsum and anhydrous gypsum can be used as gypsum.

Further, the solidifying material for organic soft ground of the present invention is mixed with a target organic soft ground in the form of powder or slurry to improve the ground. Here, the organic soft soil is a few percent of organic matter that has been decomposed in mineral clay soil.
It is a viscous soil having a very low strength and a high compressibility, and in the present invention, it refers to a target soil which is difficult to improve with a normal solidified material. Regarding this organic matter content, for example, black box and the like generally show the organic matter content (geological engineering standard: JGS T231-199).
0) and ignition loss (geological engineering standard: JGS T221-
1990) shows a numerical value of about 5 to 30%. Furthermore, it is said that it is particularly difficult to improve among the organic soft soils, and peat and black mud, etc., which are classified as high organic soils by the soil engineering classification method, are mostly composed of organic substances and are extremely high. Has an organic content. For example, in peat in Hokkaido, the ignition loss test (in the Geotechnical Engineering Standards,
The organic content of high organic soil is measured by loss on ignition.
Those exceeding 0% are also widely distributed. Incidentally, in the improvement of the organic soft soil, the improvement effect is different depending on the difference in the amount and quality of the contained organic matter, and the organic soft soil which is the object of the present invention is a general soft soil as shown here. It is not limited by the amount of organic matter according to typical test methods.

[0020]

EXAMPLES Table 1 shows the properties of peat (Kyowa, Hokkaido), which is an organic soft soil used in the test, Table 2 shows the chemical components of the slag composition used in this example, and Table 3 shows the test results. Shows the composition of the solidifying material used in Example 1. Incidentally, ordinary Portland cement was used for comparison.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

To a wet weight of 100 parts by weight of peat, which is the target soil shown in Table 1, 40 parts by weight of various solidifying materials shown in Table 3 in a 1: 1 slurry with water were added and mixed. A specimen having a diameter of 5 cm and a height of 10 cm was prepared. The obtained specimen was subjected to wet-air curing until a predetermined age in a constant temperature room at a temperature of 20 ° C. and a humidity of 80% or more. Then, a uniaxial compressive strength test was performed on the specimen after a predetermined age. The unconfined compressive strength test is based on JGSJ JGS.
It carried out according to T511-1990. Table 4 shows the results of the uniaxial compressive strength test of each specimen. FIG. 1 shows the relationship between the age and the uniaxial compressive strength. FIG. 2 shows the mixing amount of the slag composition in the solidified material and the uniaxial compressive strength. The relationship was shown.

[0025]

[Table 4]

From Table 4 and FIG. 1, all the specimens using the solidified material blended with the slag composition had a higher uniaxial compressive strength than the specimens of ordinary Portland cement, and at all ages of the test. It exhibited good strength development. In particular, the solidified material containing 5 parts by weight of the slag composition exhibited good initial strength.

FIG. 2 shows the relationship between the content of the slag composition in the solidified material and the uniaxial compressive strength. From this figure, the content of the slag composition increases at the initial age. Although the uniaxial compressive strength tends to decrease according to
On the 8th day, all showed a strength expression of 5 kgf / cm ² or more.

[0028]

As described above, by using a specific slag composition for a solidifying material for organic soft ground, not only its effective use is achieved, but also the effect as a solidifying material can be sufficiently exhibited. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between unconfined compressive strength and material age when a solidification test is performed using a solidifying material for organic soft ground of the present invention and ordinary Portland cement with peat being an organic soft soil as a target soil. is there.

FIG. 2 is a diagram showing the mixing ratio of a slag composition in a solidified material for organic soft ground of the present invention and the development of uniaxial compressive strength.

Claims (4)

[Claims] 1. A CaO content of 0 to 37% by weight and a SiO ₂ content of 2
In 3 to 90 wt% and Al ₂ O ₃ minutes 0 to 40 wt%, iron oxide, alkali components, phosphorous content, titanium oxide, one or more components selected from manganese oxide and magnesium oxide is 0.1 50% by weight or / and halogen content of 0.1%
A solidifying material for organic soft ground, comprising a slag composition of 10 to 10% by weight. 2. A solidified material for organic soft ground, comprising the slag composition, Portland cement, blast furnace slag, and gypsum. 3. The slag composition according to claim 1, wherein the sewage sludge incineration material,
Various wastes such as refuse incineration and industrial waste are used as raw materials, the components of which are adjusted with clay and limestone as necessary, melted and quenched at high temperature, and pulverized to a Blaine specific surface area of 3500 cm ² / g or more. The solidified material for organic soft ground according to claim 1 or 2, wherein: 4. A slag composition, Portland cement,
4. The blast furnace slag and gypsum compounding ratio of 1 to 80% by weight, 5 to 50% by weight, 0 to 80% by weight and 5 to 30% by weight, respectively. Solidification material for organic soft ground.