JPH07206490A - Soil mortar - Google Patents

Abstract

PURPOSE:To produce a soil mortar excellent in fluidity and strength from the soil generated on the spot without using a clay mineral by kneading the soil generated on the sot, a cement caking material, water and a specified biogum. CONSTITUTION:The soil mortar is obtained by kneading the soil generated on the spot, a cement caking material, water and the biogum selected from welan-gum, xanthan-gum or succinoglucan. This soil mortar is prepared by mixing 700-1000kg soil and 0.1-5.0kg biogum per m<3> of the soil mortar, and the water/cement caking material is controlled to 100-800%. The fluidity of the mortar is further improved by adding an appropriate amt. of dispersant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil mortar used as a backfill material for ground.

[0002]

2. Description of the Related Art When the ground for constructing a structure is uneven in strength or geology, a method of excavating the portion and refilling the soil mortar in the excavated portion is adopted. In this case, the strength of soil mortar needs to be balanced with the strength of the surrounding ground, and in general, the uniaxial compressive strength is several kgf / cm ² to several tens.
Strength of kgf / cm ² is required.

Further, a certain degree of fluidity is required so that the soil mortar can be uniformly filled in the cast place and uniform quality such as strength can be obtained. The required fluidity is generally about 200 to 250 mm as a table flow value.

Conventionally, as soil mortar satisfying such requirements, soil (or sand or a mixture thereof, hereinafter referred to as locally generated sand) locally generated, cement-based solidifying material,
A mixture of water and clay minerals was usually used. As the clay mineral, if locally generated clay is used, it is used, and if there is no locally generated clay, bentonite or the like is usually used. In any case, local occurrence sediment 700~1000K per soil mortar 1m ³
g, water / cement solidification material percentage is 300-800%
The soil mortar of the required quality was manufactured by adjusting the blending amount of clay minerals.

[0005]

In the conventional soil mortar, whichever clay such as locally-generated clay or bentonite is used, it must be deflocculated once, made into a slurry and swollen. For this reason, it takes time to manufacture the soil mortar, and it is necessary to install a mixer and a large water tank for peptization, which may be difficult to handle depending on the site.

[0006] Therefore, if a soil mortar of good quality in terms of fluidity and strength can be produced by locally-generated earth and sand without using clay minerals, it would be better than that. The present invention aims to develop a soil mortar that meets this need.

[0007]

According to the present invention, there is provided a soil mortar obtained by kneading locally generated earth and sand, cement-based solidifying material, water and biogum. Here, the locally generated sediment is 700 to 1000K per 1 m ³ of soil mortar.
g, percentage of water / cement solidifying material is 100-800%
The feature is that, instead of the clay mineral, 0.1 to 5.0 kg of biogum is added per 1 m ³ of soil mortar.

The bio-gum is preferably welan gum, xanthan gum or succinoglycan. In addition, in some cases, an appropriate amount of a dispersant for concrete is added to this biogum.

[0009]

[Function] The soil mortar of the present invention containing biogum has better fluidity after kneading than the conventional soil mortar containing clay minerals, and has a breathing value of 0% or close to 0%. Is obtained.
Further, the strength after the casting and solidification is the same as that of the conventional soil mortar.

It is considered that this is because the biogum dissolved in water has a high water retention capacity and the thickening action is not so strong. In particular, welan gum expresses this characteristic well.

For welan gum, for example, K. Clare's CHEM
SEC USA ■ APPLICATION OF NO submitted to 88 SYMPASIUM
As described in a paper entitled VEL BIOGAMS, a microbial-derived polysaccharide (BIOGAM) produced by subjecting ATTC 31555 cells of Alcaligenes strains to aerobic fermentation under carefully controlled conditions. The general structure is
Indicated by.

[0012]

[Chemical 1]

That is, the main chain of this BIOGAM has two D
-Glucose, 1 D-glucuronic acid and 1 L
-Rhamnose, the side chain is composed of one rhamnose or one mannose.

Such welan gum is available as a dry powder product, but when this welan gum powder is added to a mortar compounding system in an extremely small amount, it exhibits remarkable pseudoplasticity and exhibits a suspension stabilizing effect of fine particles. For this reason, material separation is suppressed during curing until the fluidity is sacrificed.

The same action is exhibited by biogum such as xanthan gum and succinoglycan. Xanthan gum is a biopolymer produced by a known bacterial species of Xanthomonas campestris. As shown in the general formula "Chemical formula 2", the main chain is composed of two glucoses, the side chain is two mannose and one glucoron. It consists of acid.

[0016]

[Chemical 2]

This xanthan gum can also be collected in powder form by using, for example, glucose or starch as the medium, fermenting it with the bacteria, and purifying the polysaccharide produced outside the cells.

Succinoglycans are, for example, Aggrobact
erium tumefaciens 1-736 (CNCM-In-stitut Pasteur) is a microbial fermentation polysaccharide produced by a bacterial species, which was fermented by the bacterium using glucose as a medium and produced outside the cells. The polysaccharide can be purified and collected in powder form.

Succinoglycan is disclosed in, for example, JP-A-4-253742.
As described in the publication, the basic structure is said to contain glucose, galactose and succinyl residues, but succinoglycans usable in the present invention include, for example, glucose, galactose, pyruvic acid or its Consists of salts, acetic acid or its salts, the molar ratio of which is 5-8: 1-2: 0.5-2: 0.5
There are ~ 2.

Strictly speaking, each of these bio-gum has a slight difference in its action and effect, but when it is compounded in a soil mortar, it does not increase the viscosity so much and suppresses the material separation while maintaining the fluidity. Therefore, all of them can eliminate the breathing of soil mortar and develop a uniform strength. Such an effect is brought about by the addition of 0.1 to 5.0 kg, preferably 0.5 to 3.0 kg per m ³ of soil mortar.

As the cement-based solidifying material used in the present invention, any material used in conventional soil mortar can be used. Depending on the type of cement, the amount of the cement solidifying material is generally about 150 to 230 kg / m ³ . In addition, the amount of water can be made slightly higher than that of the conventional soil mortar in the range of 250 to 800% in terms of the water solidifying material ratio.

Further, in addition to the addition of biogum, the soil mortar of the present invention can further secure fluidity by adding an appropriate amount of a dispersant generally used as an admixture for concrete. Examples of the dispersant that imparts fluidity and filling properties to soil mortar whose viscosity has been increased by the addition of biogum include, for example, high-performance water-reducing agents or high-performance AE water-reducing agents used for ordinary concrete mixing, more specifically, Naphthalene sulfonate-based, melamine sulfonate-based, polycarboxylate-based, and amino sulfonate-based dispersants are suitable.

The amount of such a high-performance water-reducing agent or high-performance AE water-reducing agent added to the soil mortar has a proper range depending on its type, but it is generally 0.5 to 5 times the compounding amount of biogum. It may be used in the range of. In this case, it is convenient to use a premix of biogum and dispersant. This premix serves to improve the dispersion of biogum in the mortar.

Upon kneading the soil mortar, it is possible to disperse it in the mortar simply by adding biogum into the mixer. It is also possible to disperse the bio-gum sufficiently by putting the bio-gum in an agitator car for mortar transportation and rotating the agitator at high speed.

[0025]

[Example] Soil mortar having the composition shown in Table 1 was kneaded, and the breathing rate and the table flow value were measured. In addition, the uniaxial compressive strength was measured on the 28th day by the specified test. The results are also shown in Table 1. The cement-based solidifying material used was "Krinset" manufactured by Nippon Cement Co., Ltd., all sand was new sand with a specific gravity of 2.70, and the clay used in the conventional example was bentonite of Nishiyama mudstone.

[0026]

[Table 1]

As is clear from the results shown in Table 1, although the soil mortar of the present invention does not use clay, it is not inferior in strength to conventional soil mortar using clay and suppresses breathing. However, it can be seen that it maintains high fluidity.

[0028]

As described above, according to the present invention, a good quality soil mortar excellent in filling property and homogeneity can be produced without using a clay mineral in particular. And, unlike the conventional process, the process of deflocculating and swelling clay is unnecessary, and there is no need to install a mixer or water tank for this. Moreover, the biopolymer according to the present invention has good kneadability with soil mortar and can be easily mixed with the mortar, so workability is also good, and it is easy to adjust the strength to the same level as the strength of the surrounding ground. . Therefore, the on-site workability of the backfilling method is greatly improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // (C04B 28/02 24:38 Z 14:04 Z 18:12) (72) Inventor Shigematsu Kazuo, Tobita, 2-1-1, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Masayoshi Minami 1-29 Kitahama East, Chuo-ku, Osaka City, Osaka Prefecture Sanai Co., Ltd. (72) Inventor Masayoshi Yoshizaki No. 1-29 Kitahama East, Chuo-ku, Osaka-shi, Osaka Prefecture Sansan Co., Ltd.

Claims (3)

[Claims] 1. Locally generated earth and sand, cement-based solidifying material,
Soil mortar made by kneading water and biogum selected from welan gum, xanthan gum or succinoglycan. 2. A local generated sediment 700~1000Kg per soil mortar 1 m ^3, Baiogamu is formulated in soil mortar 1 m ³ per 0.1 to 5.0 Kg, and wherein the percentage of water / cement solidifying material is 100 to 800% Item 2. The soil mortar according to Item 1. 3. The soil mortar according to claim 1, wherein the kneaded material contains a dispersant for concrete.