JPS593501B2 - soil conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soil improver, and more particularly to a soil improver used for soil treatment such as strengthening soft ground or stopping water from leaking ground.

Conventionally, cement milk alone, a mixture of cement and sodium silicate, a mixture of sodium silicate and calcium chloride, or a mixture of sodium silicate and organic esters or organic aldehydes have been used as soil conditioners. However, if cement is used, depending on the type of soil (for example, if the soil is fine), the cement particles may be affected by the oral effects and the range of use is narrow.

When a mixture of sodium silicate and calcium chloride is used, there are problems such as the inability to adjust the gel time. In addition, using a mixture of sodium silicate and organic esters or organic aldehydes does not have the above disadvantages, but there is a risk that the organic substances used may mix into groundwater, so it is necessary to carefully check the impact on groundwater. There are complex problems in its use, such as: Recognizing this current situation, the present inventors conducted repeated research to develop a completely inorganic soil conditioner that does not have the drawbacks and problems mentioned above. We have discovered a soil conditioner that can be injected with low viscosity and produces solids with even better strength.

That is, the present invention provides (1) silicic acid leakage or potassium silicate, (2) acidic alkali metal salts (excluding mixtures of acidic alkali sulfates and acidic alkali phosphates), (
3) A soil conditioner containing as essential ingredients 3) a water-soluble neutral salt of a divalent metal and (4) a water-soluble neutral salt of a trivalent metal selected from aluminum or iron. The sodium silicate used in the present invention is JIS-1
Examples include No. 1, No. 2, and No. 3 stipulated in 408, but especially sodium silicate J, which is used for soil treatment.
IS No. 30 is preferred.

Potassium silicate can also be used. Examples of the acidic alkali metal salts used in the present invention include acidic alkali metal salts of phosphate such as acidic sodium phosphate and acidic potassium phosphate; acidic sodium pyrophosphate, acidic potassium pyrophosphate, acidic sodium metaphosphate, and acidic metaphosphate. Acidic condensed alkali phosphates such as acid potassium, acidic sodium tripolyphosphate, and acidic potassium tripolyphosphate;
nl-rimetal salts; alkali metal bisulfates such as sodium bisulfate and potassium bisulfate; alkali metal salts of bisulfite such as sodium bisulfite and potassium bisulfite; alkali metal salts of bicarbonate such as sodium bicarbonate and potassium bicarbonate Examples include water-soluble acidic alkali metal salts such as.

Among these, preferred are alkali metal acidic phosphates, alkali metal acidic condensed phosphates, alkali metal bisulfates, alkali metal bisulfites, more preferably alkali metal salts of acidic phosphates, alkali metal acidic phosphates, It is an alkali metal bisulfate salt. 2 used in the present invention
Examples of neutral salts of valent metals include neutral salts of magnesium such as magnesium chloride, magnesium sulfate, and magnesium nitrate; neutral salts of calcium such as chloride, leucochloride, and calcium nitrate; and zinc chloride, zinc sulfate, and zinc nitrate. Neutral salts of zinc such as ferrous chloride, ferrous sulfate, ferrous nitrate, etc., and neutral salts of iron (7-valent) include ferrous salts such as ferrous chloride, ferrous sulfate, and ferrous nitrate.

Among these, preferred are neutral salts of magnesium, particularly preferred are magnesinium chloride and magnesium sulfate. Examples of neutral salts of trivalent aluminum and iron used in the present invention include neutral salts of aluminum such as aluminum chloride and aluminum sulfate; iron(
Examples include neutral salts (trivalent ones).

Among these, preferred are neutral salts of aluminum, and particularly preferred is aluminum sulfate. The proportion of each component in the soil conditioner in the present invention is not particularly limited, but is usually sodium silicate or potassium disilicate (pure content).
(hereinafter referred to as component A) is 5 to 30% by weight, and acidic alkali metal salt (hereinafter referred to as component B) is 0.2 to 10% by weight.
, a neutral salt of a water-soluble divalent metal (hereinafter referred to as component C)
may be 0.2 to 10% by weight, and the water-soluble neutral salt of a trivalent or higher valent metal (hereinafter referred to as component D) may be 0.2 to 10% by weight. In addition, the solid content concentration in the solidifying agent is 5.4 to 50% by weight,
Preferably it is 10 to 30% by weight. The method of using the soil conditioner of the present invention is not particularly limited.
component system) and mix them separately at the tip of the feed tube, etc.
(3) A multi-component system (for example, a two-component system), which is sent separately through a pouring tube (for example, a Y-shaped tube), and mixed on the way.
A soil conditioner (aqueous solution) may be obtained by a method such as the above, and then applied to soil by a conventional method such as spraying, mixing, injection, or spraying.

The soil conditioner of the present invention can be used to increase the strength and bearing capacity of soil, sand, etc., reduce water permeability, and can be applied to fill cracks in the ground and rock.

In the soil conditioner of the present invention, when only acidic alkali metal salts are added to sodium silicate or potassium quesoate, a separation phenomenon (a phenomenon in which the gel naturally separates and contracts when left to stand) occurs. Extremely lacking in dimensional stability. This separation phenomenon can be solved by adding a neutral salt of a divalent metal or a neutral salt of a trivalent or higher valent metal to the above.

However, when only a neutral salt of a divalent metal is added, instantaneous setting does not occur, and although some strength is developed, it is insufficient when a large strength is required.
Further, when only a neutral salt of a metal having a valence of 3 or higher is added, the strength development is sufficiently large and is practically satisfactory, but instantaneous setting occurs and it is difficult to use. By combining and adding a neutral salt of a divalent metal and a neutral salt of a trivalent or higher valent metal, a soil conditioner with synergistically excellent strength and no flash setting can be obtained.

The soil conditioner of the present invention may include acids, cement,
Accelerators and auxiliaries such as bentonite may be added.

When the soil conditioner of the present invention is applied to soil, the gel time can be adjusted freely, there is no need to worry about flash setting, and the viscosity is low.
In addition, the injected soil has sufficient strength and waterproof properties.

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 229 parts of water was added to 409 parts of sodium silicate (JIS No. 3, specific gravity: 1.387) to obtain a liquid A.

In a separate container, 2.0 g of monobasic sodium phosphate, 29 g of magnesium sulfate heptahydrate, and 19 g of aluminum sulfate 14 hydrate were dissolved in 459 g of water to obtain liquid B. When both solutions A and B were mixed and allowed to stand at room temperature, they gelled after about 3 minutes.

The viscosity when both liquids are mixed (30 seconds after mixing) is 2.5 cps (2
0 o'clock C), and devitrification occurred 1 to 2 minutes after gelation. A, B
The unconfined compressive strength of the gel obtained by infiltrating and solidifying a mixture of both solutions into river sand with a void ratio of approximately 1 is determined using the soil test method JISA-1.
4.3k9 when measured one day after gelation using 216
It was /d. Further, the gel was immersed in water for one month, but no change in shape due to swelling or contraction was observed. Example 2 Add 259 g of water to 35 g of sodium silicate (JIS No. 3),
It was made into liquid A.

In a separate container, 1.59 g of sodium acid pyrophosphate, 2 g of potassium bisulfite, 1.59 g of magnesium chloride hexahydrate, and 29 g of aluminum sulfate 14 hydrate were dissolved in 45 g of water to prepare liquid B. The viscosity (after 30 seconds) when both solutions A and B were mixed was 2.5 cps (20° C.), and gelation occurred after about 2 minutes.

Consolidated sand was prepared in the same manner as in Example 1, and its unconfined compressive strength was measured, and it was found to be 4.5 kg/stack. Comparative example
1 Sodium silicate (JIS No. 3) 35f! 259% of water was added to prepare solution A.

In a separate container, 3.5 f1 of dibasic sodium phosphate and 39 of magnesium sulfate heptahydrate were dissolved in 459 of water to obtain liquid B. A,
The unconfined compressive strength of the gel obtained by mixing both solutions B and infiltrating and solidifying it into river sand with a void ratio of about 1 was 2.9 kg/d when measured one day after gelation.

Comparative Example 2 Solution A was prepared in the same manner as in Comparative Example 1.

In a separate container, 3.59 g of dibasic sodium phosphate and 3 g of aluminum sulfate 14 hydrate were dissolved in 479 g of water to obtain liquid B. A,
When both solutions B were mixed, they coagulated instantaneously. Comparative example 3
The table below shows the release rate of a homogel obtained by gelling a mixture having the composition shown in the table below, and the unconfined compressive strength of a sand gel obtained in the same manner as in Example 1.

Claims (1)

[Claims] 1 (A) Sodium silicate or potassium silicate, (B) Acidic alkali metal salts (excluding mixtures of alkali acidic sulfates and alkali acidic phosphates), (C) Neutral salts of water-soluble divalent metals, and (D) A soil improvement agent containing a water-soluble neutral salt of a trivalent metal selected from aluminum or iron as an essential component.