JPH0710653A - Water proof lightweight foam cured product - Google Patents

Abstract

(57) [Abstract] [Purpose] A lightweight waterproof foam that has light weight and strength as a material used for embankment and backfilling, does not crack when dried, and does not penetrate groundwater or rainwater. It is intended to be provided. [Structure] A hydraulic hardening agent, a foaming agent, a quick-setting agent, water, and an asphalt emulsion are mixed and hardened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof and light-weight foamed cured material suitable as a material used for construction, backfilling, filling, etc. of embankments in civil engineering and construction work.

[0002]

2. Description of the Related Art Conventionally, earth and sand, soil cement and the like have been used as materials used for embankment and backfilling in civil engineering and construction work. However, since the specific gravity of these materials is generally heavy, there has been a problem that slippage of the ground or large consolidation settlement occurs. As materials for solving these problems, there are styrofoam, mortar, etc., but the former has a problem in that it is soluble in organic solvents and fire resistance, and the latter is a ground material such as embankment material. However, it has a drawback that the strength is too high.

As a material for solving the problems of the above-mentioned materials, a foamed mortar in which the mixing ratio of bubbles in the foamed mortar is increased to 50% or more and the strength is suppressed to about 10 kgf / cm ² is put to practical use. . However, even this material has a defect that the wet density increases when groundwater or rainwater penetrates for a long period of time, and the initial lightweight property is lost.

Further, the material containing a large amount of bubbles as described above has a low expression strength in the initial stage of casting and a low water-tightness, so that the water content is dissipated into the air and a dry crack is generated, In addition to the entry of rainwater, it is also a structural defect such as a decrease in strength.

Therefore, an appropriate amount of water glass is added as a quick-setting agent to increase the initial strength, and several kgf / cm is set within a few hours after placing.
Bubble mortar has been developed that can develop strength of about ² .

[0006]

However, even in the above-mentioned foamed mortar containing water glass, the drawbacks due to dry cracks due to initial drying have not been eliminated.

The present invention has been made in view of the above problems, has a light weight and strength as a material used for embankment, backfilling, etc., does not cause cracks due to drying, and is used for groundwater or rainwater. The object is to provide a waterproof, lightweight foamed cured product that suppresses permeation.

[0008]

A water-proof, light-weight, foam-cured product according to claim 1 of the present invention comprises a hydraulic curing agent, a foaming agent, and
It is characterized in that a quick-setting agent, water, and an asphalt emulsion are mixed and cured.

The water-proof, lightweight foam-cured product according to claim 2 of the present invention is characterized in that the asphalt emulsion is 5 to 20 vol% of the waterproof, lightweight foam-cured product.

The present invention will be described in detail below. The water-proof light-weight foamed cured product of the present invention is cured by reacting a hydraulic curable material with water to introduce air bubbles into the cured product by a foaming agent to reduce the weight, and is cured by a quick-setting agent. It accelerates and gives strength from the initial stage of curing, and further forms an organic film on the surface of the cured body with an asphalt emulsion to suppress the dissipation of water from the cured body and the water permeability to the inside of the cured body. It is a water-proof, light-weight, foamed and cured product that has the strength of 1. and is capable of suppressing an increase in wet density even after long-term use.

Specifically, it has a water permeability which is considered to be impermeable in practice, that is, a water permeability of about 1 × 10 ^-5 cm / sec or less, and an expression strength at the initial stage of driving is several kg.
It is a hydraulically cured product having a characteristic of about f / cm ² .

As the hydraulic hardening agent used in the water-proof, lightweight foam-hardened material of the present invention, inorganic materials such as cement, lime and slag, and organic materials such as urethane prepolymer and acrylamide can be used. Cement is particularly preferable from the viewpoints of securing instant setting property and long-term strength.

Portland cement is generally used as the above-mentioned cement, but other various cements,
For example, mixed cement such as blast furnace cement and fly ash cement, or special type cement such as alumina cement can be used.

As the foaming agent, there may be used naphthalene colloidal butyl sulfonate, gelatin, light-colored derivatives such as casein, saponin, resin soap, lauryl sulfate, and the like. In the present invention, the blending amount of the foaming agent is about 0.1 to 8.0 parts by weight with respect to 100 parts by weight of the hydraulic hardening agent, although it depends on the material used. The mixing ratio of air bubbles in the cured product by the foaming agent is about 20 to 80%.

As the quick-setting agent, water glass, potassium dichromate, sodium fluorosilicate, sodium aluminate, aluminum chloride, calcium chloride and the like are used, but they are excellent in instant setting property, good strength development property, and From the viewpoint of handling safety, water glass (JIS No. 3 product (SiO ₂ content 2
8-30%)) is preferred. It should be noted that, depending on the material used, the compounding amount of the quick-setting admixture in the waterproof waterproof lightweight foamed material of the present invention is 1 with respect to 100 parts by weight of the hydraulic hardening agent.
The amount is about 0 to 100 parts by weight. Further, the mixing amount of water in the hydraulic lightweight foam-cured product of the present invention is determined by the hydraulic curing agent 10.
The amount is about 100 to 300 parts by weight with respect to 0 parts by weight.

As the asphalt emulsion, cationic type,
A nonionic or anionic asphalt emulsion is used. Cationic asphalt emulsions easily separate water due to the presence of alkalis and salts and undergo phase separation to form an organic water blocking layer. On the other hand, the anionic and nonionic asphalt emulsions have high stability even in the presence of salts, and gradually separate water to cause phase separation to form an organic water stop layer. Therefore, for mixing in the present invention, anionic and nonionic emulsions suitable for forming a highly adherent organic film on the surface of a cured product, in which phase separation occurs gently, are suitable.
From the viewpoint of forming an organic film having higher adhesion on the surface of the cured product, an anionic asphalt emulsion is particularly suitable as the asphalt emulsion to be added and mixed in the present invention.
The amount of the asphalt emulsion in the waterproof lightweight foamed cured product of the present invention is about 30 to 200 parts by weight with respect to 100 parts by weight of the hydraulic curing agent, although it varies depending on the material used.

The content of the asphalt emulsion in the cured product is preferably 5 to 20% by volume in the cured product. Because, if it is less than 5 vol%, in many cases, the water permeability of the cured product is considered to be impervious to practical use.
This is because it exceeds 10 ⁻⁵ cm / sec. Also,
This is because if it exceeds 20 vol%, the physical properties of the cured product will approach asphalt, the deformation coefficient will increase, and the creep deformation will also increase.

Next, a method for producing the waterproof, light-weight foamed cured product of the present invention will be described. The mixing method of the above-mentioned constituent materials includes (a) mixing a hydraulic hardening agent, water and a foaming agent, adding and mixing a quick-setting agent to this mixture, and finally adding and mixing an asphalt emulsion before curing begins. To do. (B) A hydraulic hardening agent, water and a foaming agent are mixed, an asphalt emulsion is added and mixed to this mixture, and finally a quick-setting agent is added and mixed. (C) A hydraulic hardening agent, water, a foaming agent, and an asphalt emulsion are mixed, and finally a quick-setting agent is added and mixed. (D) A hydraulic hardening agent, water and a foaming agent are mixed, an asphalt emulsion and an accelerator are mixed, and a mixture of these two is mixed. There are four methods.

When an asphalt emulsion is used, the asphalt adheres to the equipment, so cleaning is essential. In order to reduce this cleaning work, the method of (a) is advantageous in terms of maintenance of the manufacturing plant when extreme initial strength development is not required. On the other hand, if a quick-setting property or a property close to it is required at the time of producing a cured product, the asphalt emulsion cannot be uniformly mixed by the method of (a), so a quick-setting agent is added later (b) to (d). This method is suitable.

[0020]

According to the invention of claim 1 or 2,
The asphalt emulsion is phase-separated, an organic film is formed on the surface of the cured product, the dissipation of water from the cured product is suppressed, and cracking due to drying is prevented. In addition, the permeation of water into the cured body is suppressed.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples. Table 1 shows the materials used for the production of the waterproof, light-weight foamed cured product of the present invention and the compounding amounts thereof.

[Table 1] The materials shown in Table 1 were mixed by the above mixing method (a),
A waterproof, light-weight foam cured product was prepared. That is, ordinary Portland cement 250 kg / m ³ , foaming agent 0.6 kg /
Anion-based asphalt emulsion was added and mixed in an amount of 2.5 to 20% in an internally divided volume to a material composed of m ³ , water 300 kg / m ³ and water glass 120 kg / m ³ and having a gel time of about 14 seconds.
In addition, water glass as a material was prepared by diluting with water (water glass / water = 2) in advance during mixing so that mixing could be easily performed. Further, the mixing rate of bubbles was set to 53%. Then, the water permeation test and the strength test were carried out on the water-proof lightweight foamed cured products in which the content ratio of these asphalt emulsions was changed.

FIG. 1 shows water-proof light-weight foamed cured products obtained by changing the content of asphalt emulsion (internal volume ratio to foam mortar), and the water permeability test of these cured products on the 34th day (JIS A1218). The results are shown below. As shown in FIG. 1, it was confirmed that the hydraulic conductivity (logarithmic representation) decreased linearly as the content of the asphalt emulsion increased (the decrease in the hydraulic conductivity was 36% at a content of 2%). The content of 5% was 47%, the content of 10% was 87%, and the content of 20% was 97%).
The permeability coefficient of the material is greatly affected by the permeability coefficient of the material before the addition. It is necessary to mix the content of the asphalt emulsion at 5% or more in view of safety in order to obtain a water impermeable material for various materials. It turned out not to be.

FIG. 2 shows the waterproof light-weight foamed cured product of the present invention obtained by changing the content of asphalt emulsion.
Uniaxial compressive strength test on 7th and 34th days (JIS A12
According to 16. ) Shows the result of. As shown in FIG. 2, it was confirmed that the uniaxial compressive strength decreased as the content of the asphalt emulsion increased in each material. The strength at the age of 3 days is about 6 kgf / even when the content rate of the asphalt emulsion is 20 vol%.
It was cm ² , and it was confirmed that sufficient strength was expressed as the initial strength of the embankment. Also, the content of asphalt emulsion is 20v
The change over time in the strength of the ol% water-proof light-weight foamed cured product also increased with age, and at 34 days of age it was approximately 8 kg.
It was confirmed that at f / cm ² , sufficient strength was obtained as a material used for embankments and the like. However, when the addition amount of the asphalt emulsion is 20 vol% or more, the physical properties of the asphalt are excellent and the creep deformation and the like become large, so that it becomes difficult to use as an embankment material. Therefore, it was found that as the material used for the embankment material and the like, the content of the asphalt emulsifier must be 20 vol% or less and mixed.

As described above, according to the water-proof, lightweight foam cured product of the present invention, the materials shown in Table 1 are mixed by the mixing method (a) above, and the asphalt emulsion is produced by the action of the alkali derived from cement. Phase-separated to form an organic film in the cured product, suppressing the dissipation of water from the cured product, and preventing the cured product from cracking due to drying, so even when the content of the asphalt emulsion is 20 vol%. It was confirmed that a strength of 3 days was about 6 kgf / cm ^2, which was sufficient as the initial strength of the embankment. Further, since the above organic coating is used to suppress the penetration of water into the hardened body, the content of the asphalt emulsion is 5v.
When it is ol% or more, the water permeability can be suppressed to 1 × 10 ⁻⁵ cm / sec or less, which is considered to be impermeable in practice, and the increase in wet density due to long-term use can be suppressed.

[0025]

EFFECTS OF THE INVENTION The water-proof, lightweight foam-cured product according to the present invention has the following effects. According to the water-proof, lightweight foamed cured product of claim 1, an organic coating is formed on the surface of the cured product to suppress the dissipation of water from the cured product, prevent cracking due to drying, and enter the inside of the cured product. Since the permeation of water is suppressed, it is possible to suppress the decrease in strength due to cracks and the increase in wet density due to the intrusion of groundwater or rainwater.

According to the water-proof, lightweight foamed cured product of claim 2, the asphalt emulsion is contained in an amount of 5 to 20 vol% in the cured product.
Since it was mixed so that even when the content of the asphalt emulsion is 20 vol%, the strength is about 6k at 3 days strength.
gf / cm ² and sufficient strength expression as the initial strength of the embankment can be obtained. Further, since the penetration of water into the inside of the cured product is suppressed by the above organic film, if the content of the asphalt emulsion is 5 vol% or more, the water permeability is considered to be practically impermeable to 1 × 10 ^−5. It can be suppressed to cm / sec or less, and an increase in wet density due to long-term use can be suppressed.

[Brief description of drawings]

FIG. 1 is a view showing the results of a water permeability test of a water-proof, light-weight foamed cured product of the present invention, which is cured by changing the content of an asphalt emulsion.

FIG. 2 Ages 3, 7, 34 of the water-proof, lightweight foam-cured product of the present invention in which the content of the asphalt emulsion is changed and cured.
It is a figure which shows the result of the uniaxial compressive strength test in day.

[Explanation of symbols]

 None

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shogo Ikeda 272 Shiba, Kokubunji-cho, Shimotsuga-gun, Tochigi Nisso Chemical Industry Co., Ltd. (72) Sumio Horiuchi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction (72) Inventor Shin Uchiyama 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Takuro Odawara 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd.

Claims (2)

[Claims] 1. A waterproof, light-weight, foam-hardening material used for embankment or backfilling in civil engineering / construction work, comprising a hydraulic hardening agent, a foaming agent, a quick-setting agent, water, and an asphalt emulsion. A waterproof, light-weight, foamed and cured product obtained by mixing and curing. 2. The waterproof lightweight foamed cured product according to claim 1, wherein the asphalt emulsion is 5 to 20 vol% of the waterproof lightweight foamed cured product.