JP2509155B2 - Slope protection structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slope protection structure for preventing slope collapse, and more particularly to a slope protection structure having high strength and excellent weather resistance.

[0002]

2. Description of the Related Art A structure is constructed by mounting a formwork on a slope and placing a cement-based hardening material such as concrete on the formwork, and applying a prestressing force to an anchor placed in the ground beforehand. It is adopted to be fixed.

[0003]

A problem with such a slope protection structure is a crack generated in the structure by applying a prestressing force. A large prestressing force is applied to attract the structure to the ground, but this force causes a crack in the hardened material,
Rainwater may penetrate into the structure along these cracks, causing the internal reinforcing bars to rust and shortening the life of the structure.

Another problem to be solved by the present invention is
This is the permeation of water that inevitably occurs in the cement-based hardening material.
Cement-based hardening materials are inherently alkaline. However, due to aging, the hardening material becomes more neutral, and water easily penetrates into the hardening material through the gaps between the cement particles and the particles of the aggregate. This water also rusted the reinforcing bars inside the structure, shortening the life of the structure.

The present invention has been made to solve the above problems, and provides a slope protection structure having high strength so that cracks do not occur, excellent weather resistance, and not expensive to construct. The purpose is to do.

[0006]

The slope protection structure according to the present invention uses an ultrafine cementitious hardener mixed with ultrafine powder as a part of the structure. The ultra-fine cement hardener is a mixture of ultra-fine powder with an average particle size of 1μ or less. Silicon or siliceous dust is particularly suitable as the ultra-fine powder, and other fly ash, calcium carbonate,
A substance having low water solubility such as titanium oxide or aluminum oxide can be used. 8 to 15 parts by weight of this ultrafine powder is added to 100 parts by weight of cement, and 2 to 10 parts by weight of a high-performance water reducing agent is further added. Examples of high-performance water reducing agents include salts of melamine sulfonic acid formaldehyde condensate, salts of naphthalene sulfonic acid formaldehyde condensate, high molecular weight lignin sulfonate, polycarboxylic acid, and the like. These are kneaded at a water cement ratio of 0.3 or less to produce a cement-based hardening material. The hardening material may be used as it is in a paste form, but may be mixed with fine aggregate to be in a mortar form, or may be used as a concrete form by mixing fine aggregate and coarse aggregate.

[0007] Such cement-based hardening material is cast into a mold. The mold has a plurality of upper end bars which are main bars,
Similarly, a plurality of lower end reinforcements, which are also main reinforcements, are arranged in parallel along the natural ground, and wire mesh-like formwork plates are erected on the left and right. The metal mesh form frame plate is an expanded metal or crimp wire mesh, and the left and right form frame plates are connected by a spacer or the like. First, an ultrafine cement-based hardening material is placed in this form, and the lower end streaks are embedded in the ultrafine cement-based hardening material. After that, a normal cement-based hardening material obtained by kneading cement with water is placed in the upper and lower intermediate portions of the mold. The above ultrafine cement-based hardening material is also placed above it, and the upper end streak is embedded in the ultrafine cement-based hardening material. It is preferable that the superfine cementitious hardeners in the upper and lower portions of the mold have a total height of the structure of 1/4 to 1/3, respectively. In this way, the ultrafine cement-based hardening material is placed on a part of the structure, but it is not necessary to place the ordinary cement-based hardening material and the ultrafine cement-based hardening material on top of each other. Is not always necessary, and may be only a necessary portion, for example, a portion for fixing the anchor or a portion where stress is concentrated. The other portions may be provided with only a normal cement-based hardening material. Placing in this invention means spraying, casting in place,
Including all the swelling by iron.

In order to improve the weather resistance of the structure, an ultra-fine cementitious hardener is cast to cover the left and right mold plates from the left and right in addition to the lower and upper parts between the mold plates. A normal cement-based hardening material may be placed in the space surrounded by the ultra-fine cement-based hardening material on the top, bottom, left and right.

[0009]

[Function] The ultra-fine cement hardener has a higher strength than ordinary cement hardeners, and the ultra-fine powder is mixed between the particles of cement and aggregate, resulting in extremely high density, which prevents the infiltration of water. Hinder. By placing an ultrafine cement hardener on the upper part between the form plates, for example, when a prestressing force is applied to the anchor, this prestressing force is received by the superfine cementitious hardener having high strength, so that the structure It is difficult for cracks to occur on objects. In particular, the ultrafine cement-based hardening material has the upper end bar and the lower end bar embedded therein, so that it can be prestressed together with the reinforcing bar. Further, in a structure in which an ultrafine cement-based hardening material is cast on the upper, lower, left and right sides of the structure, water does not enter from any surface, and water does not reach the reinforcing bar. As described above, the ultrafine cement-based hardening material is not used for the entire structure but is used only for a part thereof, so that the cost can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. In the figure, 1 and 2 are the upper and lower end reinforcements, which are the main reinforcements, and are arranged in parallel vertically along the ground. The plurality of main bars 1 and 2 are surrounded by a spiral stirrup bar 3. Formwork plates 4 and 4 made of crimp wire mesh stand upright on the left and right. Formwork plate 4
4 is fixed to the stirrup muscle 3 by a spacer 5. This formwork is assembled in a lattice shape so as to extend vertically and horizontally on the slope. Ultrafine cement hardener 7 containing ultrafine powder is cast in the upper and lower parts of the mold, and the lower end streaks 2 are embedded in the hardener 7. Ultra-fine cementitious hardener 7
Vibration is applied by a vibrator, and it is placed in the lower part of the formwork so that no bubbles are generated. A mortar-like cement-based hardening material 6 obtained by kneading ordinary cement with water and fine aggregate is sprayed on the upper and lower intermediate portions between the formwork plates 4. On top of this, the ultra-fine cement-based hardening material 7
Has been sprayed. As described above, the normal cement-based hardening material 6 is placed so as to be sandwiched between the upper and lower ultrafine cement-based hardening materials 7 and 7. The height of the ultrafine cement-based hardening materials 7 and 7 is, Each is 1/4 of the total height h of the structure. In the examples, silica fume is used as the ultrafine powder, and the composition table is shown below.

[0011]

[Table 1]

In each of the formulations of the examples, the strength was close to 800 kg / cm ² or more, and the strength was high. Hardened material 7
As a result of observation, it was found that the ultrafine powder entered the gaps between the particles of the cement or the aggregate and the particles were dense, and even the liquid such as water could not enter between the particles. In other words, it is in a state in which it is difficult for water to penetrate into the hardening material 7 to cause neutralization, and it is extremely difficult for acidified rainwater to come into contact with the reinforcing bars inside the structure. .

An anchor 8 which has been previously driven in the ground is provided at this intersection, and a prestressing force is applied to the anchor 8 to fix it on the structure. 9 is a bearing plate,
Reference numeral 10 is an anchor head to which a tension material of an anchor is fixed. FIG. 3 shows another embodiment, in which a haunch-like reinforcing portion 11 is formed so as to surround the intersecting portion.

FIGS. 4 to 6 show the construction procedure when the ultrafine cemented cement hardening material 7 is placed on the top, bottom, left and right of the structure. In Fig. 4, first, the main bar 1
2. Build a formwork with stirrup streaks 3 and formwork plates 4 and 4. An ultrafine cement-based hardening material 7 is placed under the mold. (FIG. 4) Next, a normal cement-based hardening material 6 is sprayed on the upper and lower intermediate portions of the mold plates 4, 4 and an ultrafine cement-based hardening material 7 is sprayed thereon. (Fig. 5) Form frame plate 4
Put the ultra-fine cemented cement hardeners 7 and 7 on the side so as to sandwich 4 from the left and right with a trowel. (FIG. 6) As described above, in order to cover the top, bottom, left and right of the structure with the ultrafine cementitious hardening material 7, water leaching from the ground,
Rainwater does not penetrate inside the structure.

[0015]

Since the present invention has the above-mentioned structure, the following effects can be obtained. The strength of the upper part of the structure was increased by placing a super-fine cemented cement hardener with high strength in any part, such as the part where the stress of the structure is concentrated. There is no such thing as touching the rebar and corroding. Since the upper end bar and the lower end bar, which are the main bars, are embedded in the ultra-fine cemented cement hardened material placed on the upper and lower parts of the structure, the strength of the hardened material and the reinforcing bar is extremely large. Further, the ultra-fine cemented cement hardener hardly penetrates water, the water does not come into contact with the main bar, and the life of the structure is remarkably improved. By covering the upper, lower, left and right sides of the structure with the ultrafine cementitious hardening material, the permeation of water from the entire circumference of the structure is hindered and the life of the structure can be significantly lengthened. Since the ultrafine powder cement-based hardening material was used for a part of the structure and the other parts were ordinary cement-based hardening materials, it is possible to prevent the construction cost from rising.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment in which an ultrafine cementitious hardener is placed between the mold plates.

FIG. 2 is a perspective view in which the present invention is applied to an intersecting portion.

FIG. 3 is a perspective view in which the present invention is applied to an intersecting portion.

FIG. 4 is a cross-sectional view of a state in which a mold is assembled.

FIG. 5 is a cross-sectional view of a state in which a hardening material is placed in a mold.

FIG. 6 is a cross-sectional view in which ultrafine cement-based hardening material is cast on both left and right sides of the structure.

FIG. 7 is an overall view of a slope protection structure.

[Explanation of symbols]

 1 Upper-end streak 2 Lower-end streak 3 Stirrup streak 4 Formwork plate 5 Spacer 6 Cement-based hardening material 7 Superfine cement-based hardening material 8 Anchor 9 Bearing plate 10 Anchor head 11 Reinforcement part

Claims (3)

(57) [Claims] 1. A plurality of upper end streaks and a plurality of lower end streaks are arranged vertically parallel to each other along a slope, and wire mesh-like form plates are erected on the left and right sides of the left and right upper parts. 8 parts of ultrafine powder with an average particle size of 1μ or less per 100 parts by weight of cement
15 parts by weight, 2 to 10 parts by weight of a high-performance water reducing agent are mixed, and an ultrafine cement-based hardening material mixed with a water cement ratio of 0.3 or less is placed. A slope protection structure that is embedded in a material, and a cement-based hardening material made by kneading cement with water is placed in the upper and lower intermediate parts. 2. The slope protection structure according to claim 1, wherein the ultra-fine cementitious hardener is cast in the upper part and the lower part so as to occupy ¼ to ⅓ of the total height, respectively. 3. The slope protection structure according to claim 1, wherein an ultrafine cementitious hardening material is placed so as to sandwich the left and right wire mesh formwork plates so as to sandwich them from the left and right.