JP2002321957A - Rapid curing cement concrete and execution method of tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rapid curing cement concrete for execution of a tunnel by pouring into a mold frame of the tunnel, suitable for execution for repairing exposed surfaces of mountains and tunnels. SOLUTION: The rapid curing cement concrete comprises cement concrete containing a setting modifier comprising hydrated limes, organic acids, gypsum, and a water reducing agent, and a rapid curing material composed of rapid curing components and a retarder. Furthermore, it is desirable that the setting modifier is a slurry containing water, the rapid curing component is calcium aluminates, and the rapid curing material contains gypsum and further the rapid curing slurry containing water is preferable. The rapid curing cement concrete, which is prepared by mixing the setting modifier and the rapid curing material containing rapid curing components and a retarder, is characterized by execution of tunnels by successively pouring into the mold frame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rapidly hardening cement concrete used for lining such as roads, railways, and headraces when lining an exposed ground or repairing a tunnel. About. In the present invention, paste, cement, and concrete are collectively referred to as cement concrete.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the collapse of an exposed ground such as a tunnel excavation, a quick-setting spraying method in which a quick-setting agent is blended with concrete has been performed (Japanese Patent Publication No. Sho 60-4149). ).

[0003] In this spraying method, a concrete is usually prepared by mixing cement, aggregate, and water in a metering and mixing plant installed at an excavation site, transported by an agitator truck, and pumped by a concrete pump. This is a method of mixing with a quick-setting agent pumped from the other side by a converging pipe provided in the middle and spraying it as a quick-setting sprayable concrete to a predetermined thickness on the ground surface.

[0004] In this quick-setting sprayed concrete, since high-pressure air blows the concrete onto the ground surface, there is a possibility that dust will be extremely increased in the tunnel. For this reason, a dust mask or the like must be used at the time of spraying, and the workability may be reduced. Further, there is a problem that about 20 to 30% of the shotcrete falls down without adhering to the ground, which is a so-called rebound, which is economically unfavorable.

[0005] Therefore, a concrete lining method free of dust and rebound has been demanded in terms of human safety and economics. As a concrete lining method without dust and rebound, there is a method of pouring concrete using a formwork, for example, a cast-in-place lining method, an NTL method and the like. These lining methods can be used not only for secondary lining performed after spraying the sprayed concrete onto the tunnel, but also for tunnel repair lining such as a headrace tunnel.

As the lining concrete used in the method of pouring into concrete using a formwork, there is a rapidly hardened concrete made of a rapidly hardened material and concrete. Rapidly hardening concrete, for example, has a slump value of 20 after kneading.
cm, the fluidity must be sufficient to fill the inside of the formwork, and if the excavation progress of the tunnel is equal to or greater than that of the conventional spraying method, the initial strength is not excellent. No. In addition, since the concrete before the addition of the hardened material is kneaded and then pumped using a concrete pump, mixed with the hardened material and poured, it is necessary to maintain the fluidity for a certain period of time.

[0007]

As described above, the method of pouring concrete into a concrete form using a formwork requires fluidity such as easy pumping and good initial strength development. When the fluidity is maintained for a certain period of time, there is a problem that the strength expression is delayed, and the efficiency of construction is significantly deteriorated.

On the other hand, in the case of using a conventional concrete containing a rapid hardening material composed of a combination of a rapid hardening component and a retarder, or a concrete containing an ultra-rapid hardening cement, even if the strength development is sufficient, the hardening is difficult. Since the time is short, it is difficult to maintain the fluidity for a certain time, and there is a problem that the concrete may be hardened in the concrete pump.

As a result of intensive studies, the inventor of the present invention obtained a finding that can solve the above-mentioned problems by pouring a rapidly hardened cement concrete having a specific composition into a formwork in a tunnel, thereby completing the present invention. Reached.

[0010]

That is, the present invention provides a cement concrete containing a setting modifier consisting of slaked limes, organic acids, gypsum and a water reducing agent, a rapid hardening component and a setting retarder. A rapidly hardened cement concrete comprising a rapidly hardened material, wherein the hardening component is calcium aluminate, wherein the hardening component is calcium aluminate. The rapid-hardening cement concrete,
The rapid-hardening cement concrete is a rapid-hardening cement concrete containing gypsum, and the rapid-hardening material is a rapid-hardening cement slurry containing water.
Then, the method comprises a step of mixing the rapidly hardened cement concrete and continuously pouring it into a tunnel formwork.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The rapidly hardened cement concrete used in the present invention contains a hardened material and cement concrete.

When the setting modifier used in the present invention is mixed with cement concrete containing no hardened material, the effect of retarding setting is exhibited, and the fluidity of cement concrete can be maintained for a long time. It is a material that can increase the properties, and contains slaked lime, organic acids, gypsum, and a water reducing agent. The setting modifier can be used in any form of powder, slurry, or liquid.

The slaked lime used in the present invention has an effect of preventing setting and hardening of cement concrete containing no hardened material for a long time.

Furthermore, even if a large amount of organic acids and the like are used,
Also, even if the hardened material is mixed earlier than expected, slaked lime has the effect of promoting the hardening of the hardened cement concrete by coexisting with the hardened material.

The slaked limes used in the present invention include slaked lime and carbide slag by-produced when acetylene is generated from calcium carbide. Among these, carbide slag is preferred because it exhibits the best strength development after mixing with the hardened material, and is inexpensive and economical because it is a by-product.

The particle size of slaked lime is not particularly limited, but is preferably 100 μm or less, more preferably 60 μm or less.

The organic acids used in the present invention are organic acids or salts thereof. Specifically, citric acid, gluconic acid,
One or more of oxycarboxylic acids such as tartaric acid and malic acid and salts thereof can be used. As the salt, a sodium salt or a potassium salt is preferable. Among these, the organic acid is used because the coagulation time is prolonged in direct proportion to the amount used, the control is easy, the chemical reaction with the calcium component hardly occurs when the coagulation modifier is slurried, and the slurry hardly generates heat. Salts are preferred, oxycarboxylates are more preferred, and sodium citrate is most preferred.

The amount of the organic acid used is preferably 1 to 40 parts by mass, more preferably 3 to 20 parts by mass, and most preferably 5 to 15 parts by mass with respect to 100 parts by mass of slaked lime. 1
If the amount is less than 10 parts by mass, the fluidity of the cement concrete cannot be maintained, the setting delay effect of the rapidly hardened cement concrete is small, and the hardening time of the rapidly hardened cement concrete may not be secured. May be difficult to set and harden.

As the gypsum used in the present invention, any gypsum commercially available can be used, but from the viewpoint of strength development, type II anhydrous gypsum and / or natural anhydrous gypsum are preferred.

The gypsum particle size is 3000 cm ^{2 in} Blaine value.
/ G or more is preferable, and 4000 to 7000 cm ² / g is more preferable. If it is less than 3000 cm ² / g, the initial strength development may be reduced.

The amount of gypsum used is preferably from 10 to 200 parts by mass, preferably from 20 to 100 parts by mass, per 100 parts by mass of slaked lime.
Parts by mass are more preferred. If the amount is less than 10 parts by mass, the pumpability of the cement concrete and the long-term strength development of the rapidly hardened cement concrete may be small. There is.

The water reducing agent used in the present invention is one that maintains the effect of retarding the setting and fluidity, and may be any of liquids and powders.

Examples of the water reducing agent include lignin sulfonates and derivatives thereof, and high-performance water reducing agents. One or more of these can be used. Among these, a high-performance water reducing agent is preferred because of its large setting delay effect, fluidity, and pumpability.

Examples of the high performance water reducing agent include polyol derivatives such as polyethylene glycol, aromatic sulfonic acid high performance water reducing agent, polycarboxylic acid high performance water reducing agent, melamine high performance water reducing agent, and mixtures thereof. Can be Among these, an aromatic sulfonic acid-based high-performance water reducing agent is preferred in view of the large retardation effect, fluidity, and pumpability.

The aromatic sulfonic acid of the aromatic sulfonic acid-based high-performance water reducing agent includes aromatic sulfonic acid and / or aromatic sulfonic acid formalin condensate.

The aromatic sulfonic acids include naphthalene sulfonic acid, alkyl naphthalene sulfonic acid, bisphenol A sulfonic acid, phenol sulfonic acid, trisphenol sulfonic acid, 4-phenoxybenzene-4'-sulfonic acid, methyldiphenyl ether sulfonic acid, and And anthracenesulfonic acid. Further, the aromatic ring may have an alkyl group. Examples of the aromatic sulfonic acid formalin condensate include a formalin condensate of these aromatic sulfonic acids. Among these, aromatic sulfonic acid formalin condensate is preferred in terms of large setting delay effect, fluidity, and pumpability, and naphthalene sulfonic acid formalin condensate, alkyl naphthalene sulfonic acid formalin condensate, and bisphenol A sulfonic acid One or more members of the group consisting of formalin condensates are more preferable, and β-naphthalenesulfonic acid formalin condensate (hereinafter referred to as β-NS) is most preferable.

The amount of the water reducing agent to be used is preferably 1 to 10 parts by mass, more preferably 3 to 7 parts by mass, per 100 parts by mass of slaked lime. If the amount is less than 1 part by mass, the pumpability of the cement concrete is small, the fluidity cannot be maintained, the setting delay effect of the rapidly hardened cement concrete is small, and the hardening time of the rapidly hardened cement concrete may not be secured. If it exceeds, the setting of the cement concrete becomes poor, which is not economical, and the initial strength development may be small.

The amount of the setting modifier varies depending on the mixing time and temperature of the cement concrete, but is preferably 0.5 to 15 parts by mass, in terms of solid content, based on 100 parts by mass of cement. Parts by mass are more preferred. 0.
If the amount is less than 5 parts by mass, the setting delay effect of the cement concrete kneaded is lost, so the fluidity of the cement concrete cannot be maintained, the pumpability of the rapidly hardened cement concrete is small, and the hardening time of the rapidly hardened cement concrete cannot be secured, After filling the rapid-hardening cement concrete into the formwork, a jumper may form on the surface of the rapidly-hardening cement concrete in the formwork, which may adversely affect the durability of the concrete. It is difficult to be cured, and there is a possibility that the initial strength expression property may be reduced.

As the cement used in the present invention, various portland cements such as ordinary, fast, moderate heat, and super fast, which are commercially available, and a mixture of these portland cements with fly ash, blast furnace slag, etc. Various mixed cements and the like. These may be pulverized and used. Of these, ordinary Portland cement and / or early strength Portland cement are preferred.

The hardened material used in the present invention contains a hardened component and a setting retarder.

The rapid hardening component used in the present invention is not particularly limited as long as it can be mixed into the rapidly hardening cement concrete. Examples of the rapid hardening component include inorganic salts such as sodium aluminate and sodium silicate, and cement minerals such as calcium aluminates. Among them, excellent setting properties such as fast setting and hardening of cement concrete,
From the viewpoint of good strength development, use of a cement mineral-based rapid hardening material is preferred, and calcium aluminates are more preferred.

The calcium aluminate used in the present invention is obtained by mixing a raw material containing calcia and a raw material containing alumina and subjecting them to a heat treatment such as firing in a kiln or melting in an electric furnace. It is a general term for substances having hydration activity with CaO and Al ₂ O ₃ as main components, and a part of CaO and / or Al ₂ O ₃ is an alkali metal oxide, an alkaline earth metal oxide, Substances substituted with silicon oxide, titanium oxide, iron oxide, alkali metal halide, alkaline earth metal halide, alkali metal sulfate, alkaline earth metal sulfate, etc., or CaO and Al ₂ O ₃
Is a substance in which a small amount of these are dissolved in a substance having as a main component. The mineral form may be either crystalline or amorphous.

Among calcium aluminates, C ₁₂ A ₇ (C is an abbreviation for CaO, A is A
l ₂ O ₃ ) is preferable, and amorphous C ₁₂ A ₇ is more preferable.

The particle size of calcium aluminates is preferably 4000 cm ² / g or more in terms of Blaine value, and is preferably 5000 cm ² / g.
cm ² / g or more is more preferable. If it is less than 4000 cm ² / g, there is a possibility that the rapid hardening property and the initial strength development property may be reduced.

In the present invention, in order to secure the mixing time of the hardened material slurry in which the hardened material and water are mixed, adjust the setting delay of the hardened cement concrete, and increase the strength development, the hardened material is used. Use a retarder in it.

Examples of the setting retarder include organic acids and alkali metal carbonates. Among these, it is preferable to use an organic acid and an alkali metal carbonate in combination, since the curing time can be controlled, the hose and the like are not blocked, and the strength development after curing is good.

Examples of the organic acids include those similar to the above-mentioned organic acids. Among these, organic acids are preferable, oxycarboxylic acids are more preferable, and citric acid is most preferable, since the curing time can be controlled and there is no blockage of a hose or the like.

Examples of the alkali metal carbonates include carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, and bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate. Of these, alkali metal carbonates are preferred, and potassium carbonate is more preferred, from the viewpoint of good strength development after curing.

When an organic acid and an alkali metal carbonate are used in combination, the mixing ratio of both is 10%.
The organic acids are preferably from 5 to 200 parts by mass, more preferably from 10 to 100 parts by mass, based on 0 parts by mass. If it is less than 5 parts by mass, the curing time cannot be controlled, the pumpability of the rapidly hardened cement concrete may be reduced, and the hose or the like may be clogged. If it exceeds 200 parts by mass, the strength expression may be reduced. .

The setting amount of the setting retarder is 0.1 to 100 parts by mass of the total of the rapid hardening component and the gypsum used if necessary.
The amount is preferably 2 to 5 parts by mass, more preferably 0.5 to 3 parts by mass. If it is less than 0.2 parts by mass, the curing time cannot be controlled, the pumpability of the rapidly hardened cement concrete is reduced, and the clogging of a hose or the like occurs, and the strength development may be reduced. There is a possibility that the strength developability may decrease.

Further, in the present invention, it is preferable to use gypsum in the rapidly hardened material in order to improve strength development.

The gypsum used in the rapidly hardened material is the same as the gypsum described above.

The amount of gypsum used in the hardened material is 10 hardened components.
20 to 250 parts by mass, preferably 5 parts by mass, relative to 0 parts by mass.
0 to 200 parts by mass is more preferred. If the amount is less than 20 parts by mass, the long-term strength developability may be small, and if it exceeds 250 parts by mass, the initial strength developability may be small.

Further, in the present invention, in order to increase the pumpability, it is preferable to include water (hereinafter referred to as slurry water) in the rapidly hardened material to form a rapidly hardened material slurry.

The amount of the slurry water used in the hardened material slurry is from 40 to 2 parts by weight based on 100 parts by weight of the hardened material containing the hardened component, the setting retarder, and, if necessary, gypsum.
00 parts by mass is preferable, and 50 to 100 parts by mass is preferable. If it is less than 40 parts by weight, the viscosity is too high and the pumpability of the rapidly hardened cement concrete is reduced, so that pumping may not be possible. If it exceeds 200 parts by weight, the water-cement ratio of the rapidly hardened cement concrete increases and the strength is developed. May be reduced.

The amount of the rapidly hardened material slurry used is
The amount is preferably 5 to 30 parts by mass, more preferably 7 to 20 parts by mass, in terms of solid content with respect to 0 parts by mass. If the amount is less than 5 parts by mass, the hardening time of the cement concrete mixed with the cement concrete and the rapid hardening material is too long, the initial setting is not sufficiently obtained, the strength developability is reduced, and the kelenium work (form) is performed. There is a possibility that it is not easy to remove the rapidly hardened cement concrete adhering to the concrete, and if it exceeds 30 parts by mass, it is not economical and the strength developability may be reduced.

The method for preparing the rapidly hardened material slurry is not particularly limited, but a rapidly hardened slurry may be prepared by mixing a rapidly hardened component, a setting retarder, and, if necessary, gypsum in advance with water. After mixing and dissolving water and setting retarder,
A rapid hardening material slurry may be obtained by mixing a rapid hardening component and, if necessary, gypsum.

In the present invention, in order to improve the properties of the rapidly hardened cement concrete before mixing and the strength properties after setting and hardening, it is selected from the group consisting of acidic substances, thickeners, ultrafine powder, and fibrous substances. One or more admixtures may be used.

The water-cement ratio (W / C) of the cement concrete used in the present invention is preferably from 35 to 65%,
40 to 60% is more preferred. If it is less than 35%, the viscosity of the cement concrete increases, and workability and pumpability may decrease. If it exceeds 65%, the strength development may be adversely affected. However, the water here does not include the water in the hardened material slurry, and the cement does not include the hardened material.

The fine aggregate ratio (S / a) of the cement concrete used in the present invention is preferably 40% or more, and is preferably 45 to 45%.
80% is more preferred. If it is less than 40%, the hose is clogged, the pumpability is deteriorated, and there is a possibility that a jumper may occur after the rapidly hardened cement concrete is put into the formwork.

The aggregate used in the present invention may be either fine aggregate or coarse aggregate. As fine aggregate, natural sand, quartz sand,
And lime sand. As coarse aggregate, river gravel,
Mountain gravel, lime gravel, and the like. The maximum particle size of the coarse aggregate is preferably 5 to 25 mm. If it exceeds 25 mm, the pumping property may be poor and the filling property in the mold may be poor.

The cement concrete used in the present invention preferably has a slump of 12 to 20 cm immediately before mixing with the rapidly hardened material in consideration of the filling property in the formwork.

The cement concrete and the hard cement slurry used in the present invention are separately pumped by a pump, and the hard cement slurry is press-fitted from a mixing pipe provided in the middle of a concrete hose and mixed to form a hard cement cement. , Which are poured into a tornel mold provided in the tunnel and filled and mixed.

The mixing mechanism of the mixing tube is not particularly limited. A baffle plate or the like may be provided in the mixing tube as long as the cement concrete and the rapid hardening material slurry have sufficient performance. However, it is preferable to provide a stirring blade in the mixing tube from the viewpoint of forcible mixing.

The hardening time of the rapid-hardening cement concrete of the present invention starts from the time when it is mixed in the mixing pipe. The hardening time is preferably 2 to 120 minutes, more preferably 5 to 60 minutes. If it is less than 2 minutes, it will be blocked in the hose, and there is a possibility that the rapid hardening cement concrete may not be sufficiently filled in the tornel formwork, and if it exceeds 120 minutes, the strength developability is reduced, and the removal of the formwork is delayed, The workability of tunnel lining may be deteriorated.

[0057]

The present invention will be described below in detail based on experimental examples. The test was performed at a temperature of 30 ° C.

EXPERIMENTAL EXAMPLE 1 The concrete mix was W / C = 52%, S / a = 52%,
360 kg / m ^{3 of} cement, and slaked lime 10
0 parts by mass, organic acids in amounts shown in Table 1, gypsum 50 parts by mass,
Concrete was prepared by adding 5 parts by mass of a powder setting modifier comprising 5 parts by mass of a water reducing agent and 100 parts by mass of cement, and kneaded for 5 hours. Thereafter, 100 parts by mass of calcium aluminates, 100 parts by mass of gypsum, and 100 parts by mass of a rapid hardening material composed of 1 part by mass of a setting retarder with respect to 100 parts by mass of the total of calcium aluminates and gypsum, and 70 parts by mass of slurry water Part of the rapidly hardened material slurry was mixed with concrete kneaded for 5 hours so that the solid content became 13 parts by weight with respect to 100 parts by weight of cement to prepare a rapidly hardened concrete. Concrete slump was measured for the concrete to which the hardened material was not added, and the hardened concrete slump and the hardening time were measured for the hardened concrete. Table 1 shows the results.

(Materials used) Cement: ordinary Portland cement, commercially available product, Blaine value 3350 cm ² / g, specific gravity 3.16 Fine aggregate: lime sand from Aomi, Niigata prefecture, specific gravity 2.64 FM =
2.82 Coarse aggregate: gravel from Himekawa, Itoigawa-shi, Niigata, specific gravity 2.65,
Maximum aggregate size 15 mm Slaked lime: Carbide slag, particle diameter 60 μm or less Organic acids: Commercial product, sodium citrate Gypsum: Commercial product, pulverized anhydrous gypsum, Blaine value 59
00cm ² / g water reducing agent: commercially available superplasticizer, beta-NS, powdery calcium aluminates: C ₁₂ corresponds to A ₇ composition, amorphous, Blaine 6050cm ² / g retarder: (Potassium carbonate: citric acid) = (7: 3)
(Mass ratio) mixture

(Measurement method) Concrete slump: Measured in accordance with JIS A 1101 “Method of slump test for concrete”. Rapidly hardened concrete slump: Immediately after mixing a rapidly hardened material slurry and concrete, it was measured in accordance with JIS A 1101 “Concrete slump test method”. Curing time: The point at which the temperature of the rapid-hardening concrete increased by 1 ° C. after mixing the rapid-hardening material slurry and concrete was defined as the curing time.

[0061]

[Table 1]

Experimental Example 2 Concrete was prepared by using a powder setting modifier consisting of 100 parts by mass of slaked lime, 10 parts by mass of organic acids, gypsum in the amount shown in Table 2 and 5 parts by mass of a water reducing agent, and a rapidly hardened material was prepared. The test was performed in the same manner as in Experimental Example 1 except that the concrete pumpability and the concrete slump were measured for the concrete not added, and the compressive strength was measured for the rapidly hardened concrete. Table 2 shows the results.

(Measurement Method) Concrete Pumpability: Concrete was mixed with a powder setting modifier and hose-pumped by a concrete pump. ○: When there is no pulsation in the hose and concrete can be continuously pumped, ○: When there is pulsation in the hose, but when concrete can be almost continuously pumped, △: When there is pulsation in the hose and the concrete is continuously pumped. The case where it was not able to be done was evaluated as x. Compressive strength: JIS
A Measured by 1108 “Test method for compressive strength of concrete”.

[0064]

[Table 2]

Experimental Example 3 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
Concrete was prepared by using a powder setting modifier consisting of parts by weight and the amount of water reducing agent shown in Table 3, and concrete pumping property and concrete slump were measured for concrete to which no hardened material was added. It carried out like Experimental Example 1 except having measured concrete slump, hardening time, and compressive strength. Table 3 shows the results.

[0066]

[Table 3]

Experimental Example 4 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
A concrete was prepared by adding a powder setting modifier consisting of 5 parts by mass of a water reducing agent and 100 parts by mass of cement as shown in Table 4, and a concrete slump was measured for concrete to which no hardened material was added. The test was performed in the same manner as in Experimental Example 1 except that the hard concrete was measured for the hard concrete slump, the hardening time, the compressive strength, the presence / absence of junkers, and the hard concrete pumpability. Table 4 shows the results.

(Measurement method) Presence or absence of junker: Rapidly hardened concrete was continuously poured into a tunnel form, and after 3 hours, the concrete surface was observed after demolding. The case where no junka was observed on the surface was evaluated as ○, the case where some junka was observed was evaluated as Δ, and the case where much junka was observed was evaluated as x. Rapid hardening concrete pumpability: 20 rapid hardening concrete
The state of pumping when the m pump was pumped was observed. The case where the pipe was not clogged was rated as ○, the case where the pipe was slightly clogged was rated as △, and the case where the pipe was clogged was rated as x.

[0069]

[Table 4]

Experimental Example 5 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
A concrete is prepared by using a powder setting modifier consisting of 5 parts by mass of a water-reducing agent and 100 parts by mass of calcium aluminates, 100 parts by mass of gypsum, and a total of 100 parts by mass of calcium aluminates and gypsum. Table 5
A hardened concrete is prepared by using a hardened material slurry composed of 100 parts by mass of a hardened material composed of a set retarder in an amount shown in Table 1 and 70 parts by mass of slurry water, and the hardening time, compressive strength, and rapidity of the rapidly hardened concrete are prepared. Except having measured the concrete pumpability, it carried out similarly to Experimental example 1. Table 5 shows the results.

[0071]

[Table 5]

Experimental Example 6 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
Concrete is prepared by using a powder setting modifier consisting of 5 parts by mass of a water reducing agent and 5 parts by mass of a water reducing agent, and 100 parts by mass of calcium aluminates, gypsum in an amount shown in Table 6, and a total of 100 parts of calcium aluminate and gypsum A rapidly hardened concrete was prepared by using a rapidly hardened material slurry composed of 1 part by mass of a setting retarder and 70 parts by mass of slurry water, and the compressive strength of the rapidly hardened concrete was measured. Except for this, the procedure was the same as in Experimental Example 1.
Table 6 shows the results.

[0073]

[Table 6]

Experimental Example 7 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
A concrete is prepared by using a powder setting modifier consisting of 5 parts by mass of a water-reducing agent and 100 parts by mass of calcium aluminates, 100 parts by mass of gypsum, and a total of 100 parts by mass of calcium aluminates and gypsum. On the other hand, a rapidly hardened concrete was prepared using a rapidly hardened material slurry consisting of 100 parts by weight of a hardened material consisting of 1 part by weight of a setting retarder and a slurry water in an amount shown in Table 7, and the compressive strength and the hardness of the rapidly hardened concrete were prepared. Except having measured the concrete pumpability, it carried out similarly to Experimental example 1. Table 7 shows the results.

[0075]

[Table 7]

Experimental Example 8 100 parts by mass of slaked lime, 10 parts by mass of organic acids, 50 gypsum
Concrete is prepared using a powder setting modifier consisting of 5 parts by mass of a water reducing agent and 5 parts by mass of a water reducing agent, and the rapidly hardened material slurry is used in an amount shown in Table 8 in terms of solid content with respect to 100 parts by mass of cement. Was prepared in the same manner as in Experimental Example 1 except that the hardening time, compressive strength, and workability of quenched concrete were measured for the rapidly hardened concrete. Table 8 shows the results.

(Measurement method) Keren workability: Rapidly hardened concrete was continuously poured into a tunnel form, and after three hours, it was removed from the frame. When the hard concrete adhering to the form was easy to remove, it was difficult to remove the hard concrete adhering to the mold. When it was required, it was evaluated as x.

[0078]

[Table 8]

[0079]

According to the present invention, the setting effect of the hardened cement concrete can be secured for a certain period of time by using the hardened cement concrete of the present invention. The hardening time of the hardened cement concrete mixed with the hardened material can be secured, the fluidity enough to fill the formwork can be maintained, the hardened cement concrete does not clog the hose, and the concrete surface in the formwork There is no jumper. Furthermore, since the rapidly hardened cement concrete is excellent in the initial strength development, the hardened cement concrete hardly adheres to the formwork, and the Keren work becomes easy. In addition, cement concrete to which no hardened material is added can maintain fluidity for a certain period of time, so that the pumpability of cement concrete is increased and can be pumped by a concrete pump. In other words, even if the mixing time of concrete is long, the hardened cement concrete obtained by mixing the hardened cement concrete and the hardened material can secure the hardening time. In this case, concrete that has been discarded every cycle can be used for the next cycle, and work efficiency and economic efficiency are expected to be improved by shortening the work cycle.

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Claims (6)

[Claims] 1. Rapid hardening comprising cement concrete containing a setting modifier consisting of slaked limes, organic acids, gypsum, and a water reducing agent, and a rapid hardening material containing a rapid hardening component and a setting retarder. Cement concrete. 2. The rapidly hardening cement concrete according to claim 1, wherein the setting modifier is a setting modifier slurry containing water. 3. The hardened cement concrete according to claim 1, wherein the hardened component is a calcium aluminate. 4. The hardened cement concrete according to claim 1, wherein the hardened material further comprises gypsum. 5. The rapid-hardening cement concrete according to claim 1, wherein the rapid-hardening material is a rapid-hardening material slurry containing water. 6. A method for lining rapidly hardened cement concrete, characterized by continuously pouring the rapidly hardened cement concrete according to claim 1 into a tunnel formwork.