Flow passage structure, mortar composition supply system, liquid quick setting material, and mortar composition

Abstract

This flow passage structure includes: a double-pipe structure including a mortar composition flow passage for supplying a mortar composition and a liquid quick setting material flow passage for supplying a liquid quick setting material, the liquid quick setting material flow passage being formed on the outer peripheral side of the mortar composition flow passage; on the downstream end portion side of the double-pipe structure, a merging portion in which the liquid quick setting material is added from the outer periphery of the mortar composition; and a merged flow passage which extends from the merging portion.

Description

Flow path structure, mortar composition supply system, liquid quick-setting material, and mortar composition

[0001] The present invention relates to a flow path structure, a mortar composition supply system, a liquid quick-setting material, and a mortar composition.

[0002] Mortar is widely used in various construction projects and is usually produced by mixing cement, aggregate, and water in a mortar mixer or the like. There are two methods for filling or applying mortar to a construction site: an injection method, in which the mortar is pumped into a formwork or the like, and an extrusion method or spraying method, in which no formwork or the like is used. In either case, the mortar is filled or applied to the construction site using a nozzle.

[0003] In the discharge method or spraying method, for example, a method is known in which mortar is compressed by air and a quick-setting agent (e.g., a liquid quick-setting agent) is supplied from a branch pipe at the confluence of the nozzle, the mortar and the quick-setting agent are mixed, and then the mixture is filled or applied to the construction site.

[0004] For example, Patent Document 1 proposes a method of spraying concrete for repairing cross sections, which includes a hollow cylindrical nozzle body and an inner tube provided within the nozzle body, supplying aggregate to the inner tube and supplying mortar to a mortar supply path provided between the nozzle body and the inner tube, mixing the aggregate into the mortar at the tip side of the nozzle body, and adding a non-alkaline liquid quick-setting admixture to the concrete sprayed from the tip of the spray nozzle toward the repair cross section.

[0005] Japanese Patent Application Laid-Open No. 2004-52542

[0006] However, in the method described in Patent Document 1, the liquid quick-setting admixture is made to merge at the tip of the nozzle, so it is not possible to appropriately adjust the mixture state of the mortar and the liquid quick-setting admixture when filling or applying it to the construction site. For example, when it is necessary to distribute the liquid quick-setting admixture unevenly on the surface of the mortar fluid or to mix it uniformly throughout the mortar fluid, it is difficult to achieve this with the method described in Patent Document 1.

[0007] In view of the above, an object of the present invention is to provide a flow path structure that can appropriately adjust the mixed state of a liquid quick-setting material when filling or applying it to a processing site.

[0008] As a result of intensive research to solve the above problems, the present inventors have come up with the following invention and found that the above problems can be solved.

[0009] [1] A flow path structure having a mortar composition flow path for supplying a mortar composition and a liquid quick-setting material flow path for supplying a liquid quick-setting material, the flow path having a double-pipe structure in which the liquid quick-setting material flow path is formed on the outer periphery of the mortar composition flow path, a confluence portion at the downstream end of the double-pipe structure where the liquid quick-setting material is added from the outer periphery of the mortar composition, and a confluence flow path extending from the confluence portion. [2] The flow path structure according to [1], further comprising a nozzle, the confluence portion being included within the nozzle. [3] The flow path structure according to [1], further comprising a nozzle, the confluence portion being included upstream of the nozzle. [4] The flow path structure according to any one of [1] to [3], wherein an inner pipe constituting the mortar composition flow path in the double-pipe structure is made of resin. [5] The flow path structure according to any one of [4] to [4], wherein an outer pipe constituting the liquid quick-setting material flow path in the double-pipe structure is made of metal. [6] A mortar composition supply system including the flow path structure according to any one of [1] to [5]. [7] A liquid quick-setting material that is added from the outer periphery of a mortar composition fluid consisting of the mortar composition before a mortar composition containing mortar is discharged from a nozzle, and becomes a mixture with the mortar composition. [8] The liquid quick-setting material according to [7], wherein the composition contains a rapid hardening material. [9] The liquid quick-setting material according to [7] or [8], wherein the mortar composition contains a retarder.

[10] The liquid quick-setting material according to any one of [7] to [9], which contains aluminum sulfate.

[11] A mortar composition containing the liquid quick-setting material according to any one of [7] to

[10] .

[0010] According to the present invention, it is possible to provide a flow path structure that can appropriately adjust the mixed state of the liquid quick-setting material when filling or applying it to a treatment site.

[0011] 1 is a schematic diagram illustrating an example of a flow path structure according to an embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating an example of a mortar composition supply system including the flow path structure according to an embodiment of the present invention.

[0012] An embodiment of the present invention (hereinafter, sometimes referred to as "this embodiment") will be described below. In this specification, the term "mortar composition" includes mortar alone, mortar to which admixtures (rapid hardening materials, retarding materials, etc.) have been added, and mortar to which coarse aggregate has also been added. Furthermore, "parts" and "%" are based on mass unless otherwise specified.

[0013] [Flow Channel Structure] As illustrated in Figure 1, the flow channel structure 10 according to this embodiment includes a mortar composition flow channel 12 for supplying a mortar composition and a liquid quick-setting material flow channel 14 for supplying a liquid quick-setting material. The flow channel structure 10 also includes a double-pipe structure 16 in which the liquid quick-setting material flow channel 14 is formed on the outer periphery of the mortar composition flow channel 12, and a confluence 18 at the downstream end of the double-pipe structure 16 where the liquid quick-setting material is added from the outer periphery of the mortar composition (mortar composition fluid). A confluence flow channel 19 extends from the confluence 18. Note that the confluence 18 in the drawing is shown for ease of understanding, and confluence does not occur only in this region. Furthermore, Figure 1 is an example of this embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0014] A mortar composition fluid consisting of a mortar composition and a liquid quick-setting material fluid consisting of a liquid quick-setting material are transported separately through a double-pipe structure 16, and a confluence 18 is formed at the downstream end of the double-pipe structure 16, where the liquid quick-setting material joins (starts to join) from outside the mortar composition fluid, producing a confluence. Then, as this confluence is transported through a confluence flow path 19 extending from the confluence 18, the liquid quick-setting material that has joined from outside the mortar composition fluid comes to be present inside. In other words, by changing the length of the confluence flow path 19 in the above configuration, or by determining the position of the flow path structure when filling or applying the mortar composition to a construction site, the mixed state of the liquid quick-setting material can be appropriately adjusted, such as whether it is unevenly distributed on the surface side of the mortar composition or whether it is uniformly distributed throughout the interior.

[0015] From the viewpoint of adjusting the mixed state well, the ratio (Y / X) of the diameter (X) of the mortar composition flow path 12 to the length (Y) of the double-pipe structure 16 is preferably 0.5 to 3.0, and more preferably 0.8 to 2.0.

[0016] From the viewpoint of pumpability of the mortar composition, the inner diameter of the mortar composition flow path 12 is preferably 4.5 to 79.5 mm, and more preferably 9.5 to 54.5 mm.

[0017] From the viewpoint of pumpability and the amount of the liquid quick-setting material to be added, the inner diameter of the liquid quick-setting material flow path 14 is larger than the inner diameter of the mortar composition flow path 12, and is preferably 5 to 80 mm, more preferably 10 to 55 mm.

[0018] As described above, the supplied liquid quick-setting material merges with the mortar composition at the confluence, and the mixed state of the liquid quick-setting material in the mortar composition changes as it flows through the confluence channel. Therefore, if the confluence of the channel structure is set within a nozzle, the liquid quick-setting material is filled or applied to the construction site immediately after merging, making it easier to unevenly distribute the liquid quick-setting material on the surface. In other words, if it is easier to unevenly distribute the liquid quick-setting material on the surface, it is preferable that the channel structure according to this embodiment has a nozzle and includes a confluence within the nozzle. For example, in applications involving layering such as 3D printing, uneven distribution of the liquid quick-setting material on the surface allows the surface to set and harden preferentially, improving workability.

[0019] The flow path structure according to this embodiment may have a nozzle, and the confluence may be located upstream of the nozzle. By locating the confluence before the nozzle, the liquid quick-setting material can be more easily mixed uniformly throughout the mortar composition. This has the advantage of stabilizing the quality and physical properties of the mortar composition, such as its initial strength.

[0020] To facilitate uniform mixing of the liquid quick-setting material throughout the mortar composition, the ratio (Z / X) of the diameter (X) of the mortar composition flow path 12 in the flow path structure to the distance (Z) from the upstream end (confluence 18 side) of the mortar composition flow path 12 to the nozzle discharge hole is preferably 40 to 250, more preferably 50 to 200, and even more preferably 55 to 150. By setting the ratio (Z / X) to 40 to 250, it becomes easier to more appropriately adjust the mixing state of the liquid quick-setting material. The distance (Z) can be adjusted by changing the length of the hose installed between them. Note that a nozzle commonly used for cement and concrete can be used.

[0021] Here, the inner pipe constituting the mortar composition flow path in the double pipe structure is preferably made of resin, from the viewpoint of ensuring the flow path and uniformity, specifically rubber, silicone, etc.

[0022] In addition, the outer pipe constituting the liquid quick-setting material flow path in the double pipe structure is preferably made of metal from the viewpoint of pressure resistance and pumpability, specifically stainless steel, iron, cast iron, steel, etc.

[0023] In the above description of the flow path structure, known mortar compositions and liquid quick-setting materials can be used.

[0024] [Mortar Composition Supply System] The mortar composition supply system according to this embodiment includes the flow path structure of the present invention described above. Specifically, as shown in Figure 2, the mortar composition supply system 20 according to this embodiment includes a mortar composition storage section 22 for storing the mortar composition, a pump 23 for transporting the mortar composition from the mortar composition storage section 22, a liquid quick-setting material storage section 24 for storing the liquid quick-setting material, a pump 25 for transporting the liquid quick-setting material, a flow path structure 10 according to the present invention where the transported mortar composition and liquid quick-setting material join, and a nozzle 26 for filling or applying the mortar composition to a construction site. Note that Figure 2 is an example of this embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0025] The mortar composition supply system according to this embodiment includes the flow path structure of the present invention, which allows for appropriate adjustment of the mixed state of the liquid quick-setting material when filling or applying it to the construction site. In Fig. 2, a nozzle is provided, and the confluence of the flow path structure 10 is located upstream of the nozzle 26, but this is not limited to this, and the confluence may be located within the nozzle 26. Furthermore, the mortar composition, the liquid quick-setting material, and other materials are appropriately connected by a pressure pipe or the like that pressure-feeds them.

[0026] The mortar composition preferably contains admixtures such as rapid hardening materials and retarding materials, as well as shrinkage reducing agents, short fibers, and superplasticizers.

[0027] As a mixer used for mixing when preparing the mortar composition, a mortar mixer having a ball with a spherically curved bottom, an omni mixer, a pan mixer, a pan-shaped dama cut mixer having rotating blades, a twin-shaft mixer used for mixing concrete, etc. can be used.

[0028] The cement is not particularly limited, but ordinary cement can be used. Specific examples include various types of Portland cement, such as ordinary, early-strength, and ultra-early-strength, and various blended cements in which silica fume, fly ash, or blast furnace slag is mixed with these Portland cements. Ordinary Portland cement is preferred for its ease of use.

[0029] Examples of aggregates include naturally occurring river sand, crushed stone, and silica sand. The aggregate may be mixed with cement in advance, or may be mixed when mixing the materials on-site. When mixing with cement in advance, it is preferable to use dried aggregate.

[0030] The rapid hardening material is not particularly limited, but calcium aluminate, a material containing calcium aluminate and gypsum, alumina cement, etc. can be used, and among these, a material containing calcium aluminate and gypsum is preferred.

[0031] Calcium aluminate is available in crystalline and amorphous forms, but amorphous forms are preferred in terms of rapid hardening. ２ O ３ , CaO.Al ２ O ３ , and 12CaO.7Al ２ O ３ or 11CaO.7Al in which a halogen is dissolved in the above. ２ O ３ CaF ２ , 11CaO・7Al ２ O ３ CaCl ２ , and 3CaO・3Al ２ O ３ CaF ２ Among these, there is 12CaO.7Al. ２ O ３ It is preferable that the composition consists of the component ratio represented by the following formula:

[0032] Gypsum includes anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, which can be used alone or in combination, but anhydrous gypsum, especially type II anhydrous gypsum, is preferred in terms of strength development. When calcium aluminate is used, gypsum normalizes cement setting to enhance strength development and generates a large amount of ettringite, thereby enhancing its mechanical strength. The preferred ratio of calcium aluminate to gypsum is usually 50 to 300 parts gypsum to 100 parts calcium aluminate.

[0033] The fineness of calcium aluminate and gypsum is 1,000 cm in terms of Blaine specific surface area (hereinafter referred to as Blaine value). ２ / g or more, and 4,000 to 6,000 cm ２ / g is more preferred.

[0034] The amount of the rapid hardening material made of calcium aluminate and gypsum used is preferably 1 to 15 parts, more preferably 5 to 10 parts, per 100 parts of cement. By using an amount of 1 to 15 parts, it becomes easier to develop strength in a short period of time and ensure an appropriate working time.

[0035] The retarder is not particularly limited, but examples include hydroxycarboxylic acid retarders such as citric acid and tartaric acid. By adjusting the amount of retarder used, the time until the initial setting of the mortar composition can be adjusted within a desired range. The amount of retarder used is preferably 0.1 to 1.0 part per 100 parts of cement.

[0036] The shrinkage reducing agent is not particularly limited, but can be one based primarily on an alkylene oxide adduct (alkylene oxide-based shrinkage reducing agent) or a polyether-based shrinkage reducing agent such as a polyoxyalkylene compound. Examples of alkylene oxide-based shrinkage reducing agents include alkylene oxide adduct-based shrinkage reducing agents of lower alcohols and low-molecular-weight alkylene oxide copolymer-based shrinkage reducing agents. Other shrinkage reducing agents include alcohol-based shrinkage reducing agents, glycol ether / aminoalcohol derivative-based shrinkage reducing agents, and shrinkage reducing agents consisting of a mixture of polyoxyalkylene alcohol ether and inorganic filler. Among these, polyoxyalkylene-based shrinkage reducing agents are preferred from the perspective of initial and long-term shrinkage reduction. Furthermore, adding a shrinkage reducing agent can improve fluidity. Improving fluidity can improve pumpability when pumping through a pumping piping. The amount of shrinkage reducing agent used is preferably 0.1 to 8.0 parts, more preferably 0.5 to 7.0 parts, and even more preferably 0.5 to 5.0 parts per 100 parts of cement. By setting the content of the shrinkage reducing agent to 0.1 to 8.0 parts, it becomes easier to obtain a good shrinkage reduction effect and strength. Furthermore, by setting the content of the shrinkage reducing agent within the above range, it is possible to obtain the effect of suppressing shrinkage cracking. Furthermore, it is possible to improve the fluidity and improve the pumpability. Furthermore, by setting the content of the shrinkage reducing agent to the above upper limit or less, it is possible to prevent a decrease in the fluidity of the cement composition and also to prevent a decrease in the strength of the hardened body produced.

[0037] Types of short fibers include polymer fibers such as vinylon fibers, polypropylene fibers, and nylon fibers, and inorganic fibers such as steel fibers, glass fibers, and carbon fibers. The length of the short fibers is preferably 12 mm or less. If the length is 12 mm or less, clogging of the spray nozzle with mortar becomes easier to prevent. The amount of short fibers used is preferably 0.05 to 2.0 parts, and more preferably 0.1 to 1.0 parts, per 100 parts of cement. When the amount is 0.05 to 2.0 parts, good durability becomes easier to obtain.

[0038] The fluidizing agent is not particularly limited, but examples thereof include melamine-based fluidizing agents, naphthalene-based fluidizing agents, lignin-based fluidizing agents, and polycarboxylic acid-based fluidizing agents, and are used to adjust the fluidity of mortar. The amount of fluidizing agent used is preferably 0.02 to 1.0 parts, more preferably 0.05 to 0.5 parts, per 100 parts of cement. When the amount is 0.02 to 1.0 parts, the effect of improving fluidity is more easily exhibited.

[0039] In the mortar composition, the water / cement ratio is preferably 30 to 55%, more preferably 35 to 45%. By setting the ratio at 30 to 55%, sufficient fluidity for pumping is easily obtained, and material separation is less likely to occur in the hose during pumping.

[0040] As the pressure pipe for pressure-feeding materials such as the mortar composition and the liquid quick-setting admixture, a chemical hose, a hose containing a pressure-resistant metal mesh (pressure hose), or a metal pipe can be used. Usually, a chemical hose or a pressure hose is used, and it is preferable to use metal pipes before and after the chemical hose or pressure hose.

[0041] There are no particular restrictions on the length of the pressure pipe, and the length used will vary depending on the construction situation, but a pipe of 5 to 30 m is usually used. The diameter of the pressure pipe is usually 1 to 2 inches, taking into account the pumping performance and workability such as handling the pressure-resistant hose.

[0042] [Liquid quick-setting material] The liquid quick-setting material according to this embodiment is a liquid quick-setting material that is added from the outer peripheral side of the mortar composition fluid before the mortar composition fluid containing mortar is discharged from a nozzle, and is combined with the mortar composition.

[0043] In this embodiment, by using the flow path structure described above, the liquid quick-setting material can be mixed into the mortar composition in a desired state. The mortar composition may be any of those described above. Therefore, the mortar composition fluid preferably contains the quick-hardening material described above. Furthermore, the mortar composition fluid preferably contains the retarding material described above.

[0044] Examples of the liquid quick-setting material according to this embodiment include aluminum sulfate, calcium nitrite, sodium silicate, calcium silicate hydrate, etc., and from the viewpoint of reactivity with the mortar composition, it is preferable that the liquid quick-setting material contains aluminum sulfate.

[0045] For example, when the liquid quick-setting material is an aluminum sulfate aqueous solution, the aluminum sulfate concentration is preferably 15% or more. By having an aluminum sulfate concentration of 15% or more, it is possible to reduce sagging of the sprayed material after spraying. As the aluminum sulfate aqueous solution, commercially available products include aluminum sulfate [Al ２ (SO ４ ) ３ ] Concentrations of 26.8 to 27.4% are available and can be used satisfactorily.

[0046] In this embodiment, the aluminum sulfate aqueous solution is further mixed with the aforementioned delay material, thereby making it possible to ensure a workable time after discharge. The mixing ratio of the delay material to the aluminum sulfate aqueous solution is preferably 0.1 to 1.0 parts per 100 parts of aluminum sulfate from the viewpoints of ensuring a workable time and rapid strength development.

[0047] [Mortar composition] The mortar composition (quick-setting mortar composition) according to this embodiment contains the liquid quick-setting material of the present invention described above. Specifically, by containing the liquid quick-setting material of the present invention, a mortar composition for filling or application can be obtained that can appropriately mix the liquid quick-setting material when filling or applying it to a construction site.

[0048] In the mortar composition of this embodiment, the inclusion of the shrinkage reducing agent described above improves the fluidity, and the pumpability when pumped through the pumping pipe can be improved.

[0049] Furthermore, the mortar composition according to this embodiment preferably has a mini-slump of 35 mm to 90 mm, more preferably 50 mm to 85 mm, measured immediately after mixing (immediately after discharging) in accordance with JIS A 1171. When the mini-slump is in the above range, it is possible to achieve both pumpability and lamination property (shape retention).

[0050] [Experimental Example 1] (Example 1) 100 parts of ordinary Portland cement (specific gravity 3.16), 250 parts of fine aggregate (limestone sand from Omi-cho, Niigata Prefecture, specific gravity 2.70), 20 parts by mass of the following rapid hardening material relative to the cement, and 0.5 parts by mass of retarder (sodium citrate) relative to the cement were mixed to prepare a mortar composition with a water / cement ratio of 45%, which was then pumped into a nozzle. Rapid hardening material: 12CaO.7Al ２ O ３ (100 parts of reagent grade calcium carbonate and aluminum oxide were mixed in a molar ratio of 12:7 and baked at 1,350°C for 3 hours, this process being repeated twice) and 100 parts of type II anhydrous gypsum were mixed and ground. Blaine value: 5,000 cm ２ / g

[0051] A 27% aqueous solution of aluminum sulfate was used as a liquid quick-setting material, which was pumped into the nozzle by a diaphragm pump.

[0052] The nozzle includes the flow path structure shown in Figure 1, and the mortar composition is transported through this flow path structure. The liquid quick-setting material is transported through a liquid quick-setting material flow path formed on the outer periphery of the nozzle, and the liquid quick-setting material is added from the outer periphery of the mortar composition at the confluence. The mortar composition to which the liquid quick-setting material has been added is discharged into a formwork through the confluence flow path extending from the confluence.

[0053] The flow path structure had an inner diameter of the mortar composition flow path of 24 mm. The inner diameter of the liquid quick-setting material flow path in the double-pipe structure was 25 mm. The ratio (Y / X) of the diameter (X) of the mortar composition flow path to the length (Y) of the double-pipe structure 16 was 1.0. The inner pipe constituting the mortar composition flow path in the double-pipe structure was made of rubber, and the outer pipe constituting the liquid quick-setting material flow path was made of stainless steel.

[0054] Example 2 A mortar composition containing a liquid quick-setting material was discharged from a nozzle into a formwork in the same manner as in Example 1, except that a flow path structure was provided immediately before the nozzle.

[0055] Comparative Example 1 The mortar composition to which the liquid quick-setting material had been added was discharged from the nozzle into a formwork in the same manner as in Example 1, except that a two-shot method was adopted in which the mortar composition and the liquid quick-setting material were separately sent to the nozzle by a pump and mixed together at the moment when they were discharged from the tip of the nozzle.

[0056] The uniformity of setting of the mortar composition after discharging was evaluated as follows. (Uniformity of Setting) In accordance with "Quality Standard for Accelerator for Shotcrete (Mortar) (Draft) (JSCE-D 102) Appendix 3 (Regulations)", the penetration resistance of the mortar was measured at 12 points, the average (penetration resistance value after 30 minutes) was calculated, and the standard deviation was calculated to evaluate the uniformity. The measurement points were 16 cm using a container with the partition frame of the formwork specified in JIS R 5201 removed. ２ The results are shown in Table 1.

[0057]

[0058] Comparative Example 1 had a lower penetration resistance value and greater variation than Examples 1 and 2. In contrast, Examples 1 and 2 both had high penetration resistance values, indicating that the liquid quick-setting material was functioning effectively. Example 1 contained the flow path structure shown in Figure 1 within the nozzle. That is, since the flow path structure was located closer to the application site than Example 2, the penetration resistance value and uniformity were lower than Example 2. This is presumably because it was easier to distribute the liquid quick-setting material unevenly on the surface than in Example 2.

[0059] [Experimental Example 2] A mortar composition containing a liquid quick-setting material was discharged from a nozzle and hardened in the discharged shape in the same manner as in Example 2, except that the ratio (Z / X) of the diameter (X) of the mortar composition flow path in the flow path structure to the distance (Z) from the upstream end of the mortar composition flow path to the nozzle discharge hole was set to 59 and 118. A test specimen was prepared by scraping off a portion of the surface of the hardened test specimen. ２ O ３ The ratio was measured using an X-ray fluorescence analyzer (Rigaku: X-ray fluorescence analyzer ZSX100e, etc.).

[0060] Comparative Example 2 The procedure was the same as in Example 2, except that the mortar composition and the liquid quick-setting admixture were mixed for 3 minutes using a mortar mixer without using a flow path structure to prepare a test specimen. The results are shown in the table below.

[0061]

[0062] From the above table, it can be seen that the mixed state of the liquid quick-setting material (aluminum sulfate) can be changed by changing Z / X. In other words, by changing Z / X, a desired mixed state can be achieved.

[0063] The flow path structure of the present invention can be suitably used in the fields of civil engineering and construction when filling or applying a mortar composition to a construction site.

[0064] 10 Flow path structure 12 Mortar composition flow path 14 Liquid quick-setting material flow path 16 Double pipe structure 18 Confluence portion 19 Confluence flow path

Claims

1. A flow path structure having a mortar composition flow path for supplying a mortar composition and a liquid quick-setting material flow path for supplying a liquid quick-setting material, a double pipe structure in which the liquid quick-setting material flow path is formed on the outer periphery of the mortar composition flow path, a junction part at the downstream end part of the double pipe structure where the liquid quick-setting material is added from the outer periphery of the mortar composition, and a junction flow path extending from the junction part.

2. The flow path structure according to claim 1, further comprising a nozzle, the confluence being included within the nozzle.

3. The flow path structure according to claim 1, further comprising a nozzle, and the confluence portion is located upstream of the nozzle.

4. A flow path structure according to claim 1, wherein the inner pipe constituting the mortar composition flow path in the double pipe structure is made of resin.

5. A flow path structure according to claim 1, wherein an outer pipe constituting the liquid quick-setting material flow path in the double pipe structure is made of metal.

6. A mortar composition supply system comprising a flow path structure according to any one of claims 1 to 5.

7. A liquid quick-setting material that is added from the outer periphery of a mortar composition fluid consisting of a mortar composition before the mortar composition containing mortar is discharged from a nozzle, and that merges with the mortar composition.

8. The liquid quick-setting material according to claim 7, wherein the mortar composition contains a quick-setting material.

9. The liquid quick-setting material according to claim 7, wherein said mortar composition contains a retarding material.

10. The liquid quick-setting material according to claim 7, which contains aluminum sulfate.

11. A mortar composition comprising the liquid quick-setting material according to any one of claims 7 to 10.

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