JP2002104856A - Spraying material and spraying process using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spraying material of cement concrete capable of preventing hanging down of concrete immediately after spraying or slipping down from a slope, ensuring fine sight of the slope face because of having time for trowel-finishing, especially preventing sliding of a steep slope, and to provide a spraying process using the spraying material. SOLUTION: This spraying material comprises polyalkyleneoxide, a condensation product containing bisphenols especially having an average molecular weight of 5,000 to 30,000, aluminum lactate and cement. This spraying process comprises mixing cement concrete comprising cement and polyalkyleneoxide with the condensation product containing bisphenols and aluminum lactate immediately before spraying, and spraying the spraying material to the steep slope in which reinforcements are arranged to form a framework.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blasting material and a blasting method using the same, particularly a blasting material for cement concrete applied to prevent landslides on a slope, and a sloping surface which is easily collapsed. For example, the present invention relates to a spraying material sprayed on a frame skeleton arranged in a lattice (cross-girder shape) and a slope spraying method using the same. The cement concrete used in the present invention is a general term for mortar and concrete. Parts and percentages used in the present invention are based on mass unless otherwise specified.

[0002]

2. Description of the Related Art Slope means highways, dams,
It refers to an inclined surface made of cut soil, embankment, etc. around a steep slope. If this slope is left as it is, it may be eroded by natural weathering, heavy rain, etc., and may collapse due to landslides. Therefore, it is necessary to protect the slope.

Conventionally, concrete has been directly sprayed to prevent collapse of the slope. Recently, however, a wire frame or a plurality of reinforcing bars has been arranged in a grid on the slope to form a frame skeleton. It has been practiced to increase the reinforcing effect, drive an anchor into the intersection, and then spray concrete to make a reinforced concrete frame to stabilize the slope (Japanese Patent Publication No. 58-058493). Above all, a free frame method in which a deformable wire mesh or reinforcing bar is arranged directly on a slope is often used. At that time, make a simple plant at the construction site,
Hard concrete with a slump of 0 cm is prepared, sprayed, and then the surface is ironed. However, this method has a problem that the construction efficiency is as low as about 2 m ³ / hr, and the compounding of the material requires labor, resulting in an increase in cost.

[0004] For this reason, it has been considered that the construction efficiency is increased by increasing the spraying speed and concrete is supplied from the ready-mixed plant, the number of manpower is reduced, and the cost is reduced. In order to increase the spraying speed, it is necessary to increase the slump of the concrete. However, when the slump is large, there is a problem that the concrete flows down from the slope when spraying.

For this reason, it is necessary to increase the viscosity of the concrete immediately after spraying to reduce the slump and prevent the concrete from sliding down. If a quick-setting agent is used during spraying, concrete can be prevented from sliding down,
There is a problem that ironing cannot be performed because the sprayed concrete hardens quickly, and the beauty of the slope surface is impaired.

[0006] Thus, there has been a demand for a spraying material that mixes with concrete at the time of spraying to prevent the concrete from slipping down and to secure a pot life enough to allow ironing.

The inventor of the present invention has made intensive studies to solve the above-mentioned problems, and as a result, obtained the finding that the above-mentioned problems can be solved by using a specific spraying material, thereby completing the present invention. Was.

[0008]

That is, the present invention relates to a spray material containing a polyalkylene oxide, a bisphenol-based condensate, and aluminum lactate, wherein the bisphenol-based condensate has an average molecular weight of 5,000 to 30,000. A spraying material, further containing the cement, the spraying material containing 0.1 to 3 parts of aluminum lactate per 100 parts of cement, and the spraying material using the spraying material. It is a spraying method in which cement concrete containing a part of the spraying material other than cement and cement and the remainder of the spraying material other than cement are mixed immediately before spraying, and spraying, Cement concrete containing cement and polyalkylene oxide, and bisphenol-based condensate, aluminum lactate mixed immediately before spraying A spraying method to attach,
This is a slope spraying method in which rebars are arranged on a slope to form a frame skeleton and the spray material is sprayed on the slope.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

According to the present invention, even when cement concrete having a large slump is used for the purpose of increasing the spraying speed and improving the construction efficiency, the cement concrete is prevented from sliding down by being mixed with the cement concrete at the time of spraying. And a spraying method using a spray material capable of securing a pot life such that ironing can be performed.

The polyalkylene oxide (hereinafter referred to as PAO) used in the present invention gives viscosity to cement concrete by interaction with a bisphenol-based condensate,
This prevents the cement concrete from dripping or slipping immediately after spraying. Examples of PAO include polyethylene oxide, polypropylene oxide, and polybutylene oxide. Of these, polyethylene oxide is preferable because of its large effect. The average molecular weight of PAO is preferably 1,000,000 to 5,000,000. Ten
If it is less than 0,000, the effect of preventing sagging and slippage may be small, and if it exceeds 5,000,000, the pumpability of cement concrete may be reduced. The amount of PAO used is preferably 0.001 to 0.5 part, and more preferably 0.005 to 0.5 part, based on 100 parts of cement.
Three parts are more preferred. If it is less than 0.001 part, the viscosity of the cement concrete is small, dripping occurs when spraying, and the cement concrete may flow down from the slope, and may not flow.
If it exceeds 5 parts, the viscosity of the cement concrete increases, which may cause a problem in the pumpability.

The bisphenol-based condensate used in the present invention is obtained by subjecting a bisphenol, an aromatic aminosulfonic acid, and formaldehyde to a condensation reaction, and a commercially available product can be used. Specific examples of bisphenols include, for example, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, 2,2-
Bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxybiphenyl, and these Isomers and the like can be mentioned, and these can be used in combination.
Further, specific examples of the aromatic aminosulfonic acid include 4-aminobenzenesulfonic acid, 2-amino-5-methylbenzenesulfonic acid, and isomers thereof. The average molecular weight of the bisphenol-based condensate used in the present invention is
5,000 to 30,000 are preferred. If the average molecular weight is less than 5,000, the effect of preventing the cement concrete from slipping off may be small, and if it exceeds 30,000, the strength development may be reduced. The amount of bisphenol condensate used is cement
For 100 parts, 0.1 to 1.0 part is preferable, and 0.2 to 0.5 part is more preferable. If it is less than 0.1 part, the effect of preventing the cement concrete from slipping may be small, and if it exceeds 1.0 part, the slipping may increase.

The aluminum lactate used in the present invention reduces slump by mixing with cement concrete, and prevents dripping and slippage of cement concrete immediately after spraying, and is used together with PAO or bisphenol-based condensate. By doing so, the effect of preventing sagging and slipping of the cement concrete immediately after spraying is greater than when each of them is used alone. The amount of aluminum lactate used is preferably 0.1 to 3 parts, more preferably 0.3 to 2 parts, per 100 parts of cement. If it is less than 0.1 part, the effect of preventing the cement concrete from sliding off may be small, and if it exceeds 3 parts, the setting and hardening of the cement concrete may be promoted, and it may not be possible to secure time for ironing.

[0014] The cement used in the present invention is not particularly limited, and various portland cements such as ordinary, fast, super fast, moderate heat, and low heat, and blast furnace slag, fly ash, limestone, etc. Any of various kinds of cement mixed with fine powder or silica, or expanded cement or colloid cement can be used.

In the present invention, in addition to the above-mentioned materials and aggregates such as sand and gravel, water-reducing agents, AE agents, fibers, fine powders and the like are used in combination within a range that does not substantially impair the object of the present invention. Is possible.

As the water reducing agent, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate, polycarboxylic acid type polymer compound and the like can be used. The AE agent prevents frost damage of cement concrete. Further, the fibers are particularly effective for preventing cracks in the anchor portion. And the fine powder fills the voids to form a dense structure, aiming at high strength,
Silica fume or the like can be used.

In the slope spraying method using the spray material of the present invention, the spray material may be sprayed directly on the slope, but in order to increase the reinforcing effect, reinforcing bars and the like are arranged. It is preferable to form a frame skeleton, and a free frame method is more preferable.

Here, the reinforcing bars are made of a wire mesh, a reinforcing bar, or the like. The reinforcing bars are combined to form a frame skeleton, and the cement concrete is sprayed to obtain a reinforcing concrete-containing cement concrete frame.

The method of arranging the reinforcing steel used in the free frame method is not particularly limited.
Wire mesh of 30-60cm in width and 1-3m in length (corrugated rebar φ1-3
mm) in parallel with each other at the same interval as the width of the wire mesh, and the longitudinal direction is arranged along the slope and added. A frame skeleton is formed by using spacers such as a reinforcing bar on two parallel wire nets. When extending this frame skeleton vertically and horizontally, it is preferable to drive an anchor at the intersection. It is also possible to use a frame skeleton for the intersection at the intersection of the frame skeleton. It is possible to maintain the beautiful appearance of the frame by performing spraying on the frame skeleton arranged in this manner using a spraying material, and ironing the portion of the frame skeleton protruding from the reinforcing steel.

As the slope spraying method used in the present invention, any of the generally used dry and wet spraying methods is possible. Among them, the wet spraying method is preferable because the amount of generated dust is small.

The slope spraying method of the present invention includes PAO
Is preliminarily mixed with cement concrete, and the bisphenol-based condensate and aluminum lactate are preferably mixed with the cement concrete mixed with PAO by a mixing pipe before the spray nozzle, for example. When a bisphenol-based condensate and aluminum lactate are mixed with cement concrete mixed with PAO, the slump is reduced and the pumpability is reduced. Therefore, when mixed at a location other than the above, clogging and pulsation may occur. When a bisphenol-based condensate and aluminum lactate are mixed with cement concrete mixed with PAO, the bisphenol-based condensate and aluminum lactate can be separately mixed with cement concrete mixed with PAO. It is also possible to mix the material with aluminum lactate and mix it with cement concrete mixed with PAO.

[0022]

Hereinafter, the present invention will be described in more detail based on experimental examples.

[0023] Experiment 1 unit amount of cement ^{450kg / m 3, W / C} = 45%, and s / a = 70% and the shotcrete was prepared, which concrete pumping machine "Ariba 280" by 4m ³ / hr pumping speed, 0.4M
Air was pumped at a pumping pressure of Pa. PAO shown in Table 1 was preliminarily mixed with 100 parts of cement in the concrete. In preparing the concrete, the amount of the water reducing agent was adjusted so that the slump was about 20 cm. Also, pump the bisphenol-based condensate i and aluminum lactate into
With respect to 100 parts, 0.2 parts and 0.5 parts were respectively injected into the mixing tube attached in front of the nozzle together with compressed air, mixed with concrete and sprayed. The results are also shown in Table 1.

<Materials used> Cement: ordinary Portland cement, commercial product, density
3.16 g / m ³ Fine aggregate: River sand from Himekawa, Niigata prefecture, surface dry density 2.62 g / m ³ Coarse aggregate: Billi gravel from Himekawa, Niigata prefecture, surface dry density 2.65 g / m ³ Water reducing agent: Polycarboxylic acid high Performance AE water reducing agent, commercial product PAO: polyethylene oxide (PEO), average molecular weight 2,000,000, commercial product Bisphenol-based condensate A: average molecular weight 20,000, commercial product Aluminum lactate: commercial product

<Measurement Method> Sag, etc .: A frame skeleton of 30 cm width × 30 cm thickness was crossed and placed on the slope to observe the condition when concrete was sprayed on the frame skeleton. × when dripping or slipping was observed a lot, △ when it was a little seen, ○ when it was not seen at all ○ Pot life ： The time from spraying the spray material until the dent by finger touch disappeared Workability: Workability when spraying concrete onto a frame skeleton of 10 cm wide x 40 cm long x 10 cm thick, finishing the surface of the frame skeleton with an iron and molding. ○: easy molding, △: force required for molding, ×: unable to form even with force. Pumpability: Measures the pressure in the pumping tube when pumping shotcrete. When the pressure is 0.40 to 0.55 MPa, ○, even if it becomes 0.60 MPa or more at which the inside of the pumping tube tends to close, by applying an impact to the pumping tube, it will be 0.40 to 0.55 MPa
If it becomes 管, if the pumping pipe is closed and it does not reach 0.40 to 0.55MPa even if an impact is applied to the pumping pipe. × Compressive strength: Concrete is sprayed on a frame skeleton of 50cm wide x 50cm long x 20cm thick. Specimens with a diameter of 5 cm and a length of 10 cm are cored and cured at 20 ° C and 80% RH.

[0026]

[Table 1]

Experimental Example 2 PEO was added at 0.0 to 100 parts of cement in concrete.
The same procedure as in Experimental Example 1 was carried out except that one part was mixed and the bisphenol-based condensate shown in Table 2 was used. The results are also shown in Table 2.

<Materials> Bisphenol-based condensate b: average molecular weight 5,000, commercial product Bisphenol-based condensate C: average molecular weight 10,000, commercial product Bisphenol-based condensate d: average molecular weight 30,000, commercial product

[0029]

[Table 2]

Experimental Example 3 PEO was added to 0.0 part of cement in concrete for 100 parts.
One part was mixed, and the same procedure as in Experimental Example 1 was carried out except that 0.2 parts of the bisphenol-based condensate A and aluminum lactate shown in Table 3 were used. The results are also shown in Table 3.

[0031]

[Table 3]

[0032]

According to the spraying material of the present invention and the spraying method using the same, even if concrete having a large slump is used, the concrete immediately after spraying can be used to increase the spraying speed and the construction efficiency. It is possible not only to prevent dripping or slipping off from a slope, but also to take time to perform ironing, so that it is possible to secure the beauty of the slope surface.

Claims (8)

[Claims] 1. A spray material comprising a polyalkylene oxide, a bisphenol-based condensate, and aluminum lactate. 2. The bisphenol-based condensate has an average molecular weight of
2. The spray material according to claim 1, wherein the amount is from 5,000 to 30,000. 3. A spray material comprising cement and the spray material according to claim 1. 4. The spraying material according to claim 3, wherein 0.1 to 3 parts of aluminum lactate is contained based on 100 parts of cement. 5. A spraying method comprising using the spraying material according to claim 1. Description: 6. A cement concrete containing a part of the spraying material according to claim 1 or 2 and the remaining portion of the spraying material according to claim 1 or 2 are mixed and sprayed immediately before spraying. A spraying method characterized by the following. 7. A spraying method characterized by mixing and spraying a cement concrete containing cement and polyalkylene oxide, a bisphenol-based condensate, and aluminum lactate immediately before spraying. 8. A skeleton is formed by arranging rebars on a slope, and the spray material according to claim 3 or 4 is sprayed on the slope to construct a cement concrete frame containing rebars. Slope spraying method.