Geopolymer hardened body construction method and infrared irradiation device

Abstract

To effectively heat and cure a geopolymer composition when the geopolymer composition is applied by spraying.SOLUTION: A construction method of a geopolymer hardened body forms the geopolymer hardened body by hardening a geopolymer composition (20) sprayed on a construction surface (S), and heats the geopolymer composition (20) by infrared rays irradiated by an infrared irradiation device (30).SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a construction method for a geopolymer hardened body and an infrared irradiation device. [Background technology]

[0002] Due to the problem of global warming, reducing carbon dioxide emissions has become a global issue. Because cement emits large amounts of carbon dioxide during its production, efforts are underway to reduce the amount of cement used and to develop alternative materials to cement. Geopolymers can be made into high-strength hardened materials without using cement, and are therefore expected to be a material that can reduce carbon dioxide emissions. Patent document 1 describes spraying a geopolymer composition onto a construction surface in the same manner as conventional cement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-35203 Summary of the Invention [Problem to be solved by the invention]

[0004] However, to harden a geopolymer composition, it is necessary to cure it at high temperatures in the early stages of hardening, although this depends on the materials and formulation used. There are particular challenges with methods for heat-curing geopolymer compositions at construction sites. For example, when casting geopolymer into a formwork, one possible method for heat-curing at construction sites is to heat the formwork itself. However, when spraying geopolymer compositions without using formwork, as in Patent Document 1, it is difficult to effectively heat-cure the geopolymer composition.

[0005] In view of these points, the present invention aims to enable effective heat curing of a geopolymer composition when the geopolymer composition is applied by spraying. [Means for solving the problem]

[0006] The method for applying a hardened geopolymer body involves hardening a geopolymer composition sprayed onto a surface to form a hardened geopolymer body, and heating the geopolymer composition with infrared rays emitted by an infrared irradiation device. The infrared irradiation device also includes an infrared irradiation unit that irradiates infrared rays onto the geopolymer composition sprayed on the construction surface, and an irradiation unit support that supports the infrared irradiation unit at the spraying construction site, and the irradiation unit support supports the infrared irradiation unit so that the infrared irradiation surface of the infrared irradiation unit faces the construction surface. [Effects of the Invention]

[0007] According to the present invention, when the geopolymer composition is applied by spraying, the geopolymer composition can be effectively heat cured. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a test device for thermally curing a geopolymer composition using infrared radiation. [Figure 2] 1 is a table showing the blending ratio of each component in the first example by mass. [Figure 3] 10 is a table showing test conditions of a comparative example. [Figure 4] 1 is a table showing the test conditions for Examples 1 to 5. [Figure 5] 1 is a graph showing the temperature change during heat curing of the test piece of Example 4. [Figure 6] 1 is a table showing test results of Comparative Examples 1 and 2 and Examples 1 to 5. [Figure 7] 1 is a graph showing the compressive strength of Comparative Examples 1 and 2 and Examples 1 to 5. [Figure 8] 10 is a table showing the composition of each component in the second example in terms of mass ratio. [Figure 9]1 is a diagram showing the relationship between the mixture ratio of fly ash and blast furnace slag and compressive strength. [Figure 10] FIG. 1 is a diagram showing an infrared irradiation device installed at a construction site where a geopolymer composition is sprayed onto a slope, which is the construction surface. [Figure 11] FIG. 10 is a plan view of an infrared irradiation device arranged on a slope, as viewed from above. [Figure 12] FIG. 10 is a plan view illustrating the movement of the infrared irradiating device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, with reference to the accompanying drawings, an embodiment of a method for applying a geopolymer hardened body and an infrared irradiation device according to the present invention will be described.

[0010] In the construction method of the present invention for hardened geopolymer bodies, the geopolymer composition sprayed onto the construction surface at the construction site is heated by infrared rays emitted by an infrared irradiation device, and the geopolymer composition is hardened to form a hardened geopolymer body.

[0011] The geopolymer composition is produced by mixing an alkaline-active powder active filler with a liquid alkaline activator and water, and may also contain aggregate.

[0012] The activated filler is a powder that is activated and solidified by mixing with an alkaline activator, and is a raw material whose main component is amorphous aluminum silicate, such as fly ash (lime coal), blast furnace slag, metakaolin, and volcanic ash.

[0013] The alkaline activator may be sodium silicate (water glass), sodium hydroxide, potassium hydroxide, or the like.

[0014] Then, a geopolymer composition is produced by mixing an active filler, an alkaline activator, and water, and this geopolymer composition is applied by spraying onto the application surface. The sprayed geopolymer composition is then heated and cured to harden, thereby forming a hardened geopolymer body. Heat curing of the geopolymer composition promotes the condensation polymerization reaction and accelerates the hardening of the geopolymer composition. The construction target may be, for example, a panel structure of a slope protection structure, a wall portion of a tunnel structure, or a wall portion of a building.

[0015] The inventors investigated the strength of hardened geopolymers formed by heating and curing geopolymer compositions with infrared rays. The inventors also investigated the strength of hardened geopolymers cured at room temperature and by heating in a thermostatic device as comparative examples.

[0016] FIG. 1 is a perspective view of a test apparatus 10 for infrared heat curing of geopolymer compositions. The test apparatus 10 includes a test specimen holder 12 that holds a test specimen 11 of a geopolymer composition, a weighing scale 13 on which the test specimen holder 12 is placed, an infrared irradiation device 14 that irradiates the test specimen 11 with infrared rays, and a data logger 15 that measures the temperature of the test specimen 11.

[0017] The test piece holder 12 has a plurality of cylindrical holes 12a that penetrate vertically through the test piece holder 12. The lower surfaces of the holes 12a are closed by the upper surface of the weight scale 13. The upper surfaces of the holes 12a are open upward. The test piece 11 is formed by filling a resin formwork (not shown) with the geopolymer composition, setting the formwork together with the geopolymer composition in the hole 12a, and allowing the geopolymer composition to harden to form a shape that conforms to the formwork. The test piece 11 is cylindrical, 50 mm in diameter and 100 mm in height. The weight change of the test piece 11 during heat curing is measured by a weighing scale 13. From this weight change, the amount of water evaporated from the geopolymer composition due to heat curing is measured.

[0018] A temperature sensor 16a is connected to the upper surface 11a of the test piece 11, and a temperature sensor 16b is connected to the lower surface 11b of the test piece 11. The data logger 15 measures the temperatures of the upper surface 11a and the lower surface 11b of the test piece 11 by detection by the temperature sensors 16a and 16b.

[0019] The infrared irradiator 14 is disposed so as to cover the test piece holder 12 from above. The lower surface of the infrared irradiator 14 is an infrared irradiating surface 14a that irradiates infrared rays toward the test piece 11. The infrared irradiating surface 14a faces the upper surface 11a of the test piece 11 that is exposed upward from the upper end of the hole 12a. The infrared rays emitted from the infrared irradiating surface 14 a directly strike the upper surface 11 a of the test piece 11 . The distance D between the infrared ray irradiated surface 14a and the upper surface 11a of the test piece 11 is 500 mm. The wavelength of the infrared ray irradiated by the infrared ray irradiated surface 14a is 500 to 1000 nm.

[0020] <First Example> Here, the test of the test piece 11 prepared using the test device 10 will be described. FIG. 2 is a chart showing the blending of each component in the first example in terms of mass ratio. In FIG. 2, (B) indicates an active filler, (AAS) indicates an alkaline activator, (AS1) indicates sodium hydroxide (NaOH), (AS2) indicates sodium silicate (Na2SiO3), and (W) indicates water. Fly ash was used as the active filler (B). The alkaline activator (AAS) is a mixture of sodium hydroxide (AS1) and sodium silicate (AS2).

[0021] FIG. 3 is a table showing the test conditions of the comparative example. Referring to Figure 3, in the first example, tests were conducted on Comparative Example 1, in which the geopolymer composition was cured and hardened at room temperature, and Comparative Example 2, in which the geopolymer composition was cured and hardened in a thermostatic device. The thermostatic device heats the air inside the thermostatic device using a heater, and the geopolymer composition is heated through the heated air.

[0022] For the test piece of Comparative Example 1, the geopolymer composition was filled into a paper formwork, the top surface of the formwork was covered with a film, and the specimen was cured at a room temperature of 20°C until the compression test was carried out. For the test piece of Comparative Example 2, the geopolymer composition was filled into a paper formwork, the top surface of the formwork was covered with a film, and the formwork was left to cure at room temperature of 20°C for one day. After that, the film was left to cure in a thermostatic chamber at 60°C for 24 hours without removing the film. Then, the film was left to cure at room temperature of 20°C until the compression test was performed.

[0023] FIG. 4 is a table showing the test conditions for Examples 1 to 5. The test specimens of Examples 1 to 5 were formed using a test apparatus 10 by filling a resin formwork (not shown) with the geopolymer composition and setting the formwork and the geopolymer composition in the hole 12a. After heat curing, the geopolymer composition was cured at room temperature of 20°C until the compression test was performed with the top surface of the formwork covered with a film. The test specimens were removed from the formwork before the compression test. The test specimen in Example 1 was a specimen in which the geopolymer composition was set together with the formwork in the hole 12a of the test specimen holder 12, and heat-cured for one hour by infrared irradiation using the infrared irradiation device 14. The specimen was then cured at room temperature of 20°C until the compression test was performed. During the heat-curing in Example 1, the maximum temperature detected on the upper surface 11a of the test specimen 11 was 80°C.

[0024] The test specimen in Example 2 was a specimen in which the geopolymer composition was set together with the formwork in the hole 12a of the test specimen holder 12, and heat-cured for 4 hours by infrared irradiation using the infrared irradiation device 14, and then cured at room temperature of 20°C until the compression test was performed. During the heat-curing in Example 2, the maximum temperature detected on the upper surface 11a of the test specimen 11 was 80°C.

[0025] The test specimen in Example 3 was a specimen in which the geopolymer composition was set together with the formwork in the hole 12a of the test specimen holder 12, and heat-cured for 8 hours by infrared irradiation using the infrared irradiation device 14, and then cured at room temperature of 20°C until the compression test was performed. During the heat-curing in Example 3, the maximum temperature detected on the upper surface 11a of the test specimen 11 was 95°C.

[0026] The test specimen in Example 4 was a specimen in which the geopolymer composition was set together with the formwork in the hole 12a of the test specimen holder 12, and heat cured for 8 hours a day for 3 days using infrared radiation from the infrared radiation device 14. The specimen was then cured at room temperature of 20°C until the compression test was performed. During the heat curing in Example 4, the maximum temperature detected on the upper surface 11a of the test specimen 11 was 95°C.

[0027] The test specimen in Example 5 was a specimen in which the geopolymer composition was set together with the formwork in the hole 12a of the test specimen holder 12, and heat cured for 8 hours a day for 5 days using infrared radiation from the infrared radiation device 14. The specimen was then cured at room temperature of 20°C until the compression test was performed. During the heat curing in Example 5, the maximum temperature detected on the upper surface 11a of the test specimen 11 was 95°C.

[0028] FIG. 5 is a graph showing the temperature change during heat curing of the test piece of Example 4. The heat curing of the test piece of Example 4 was carried out multiple times in a single cycle per day, consisting of a heating step I in which infrared rays were irradiated by the infrared irradiation device 14, and a cooling step C in which the infrared irradiation by the infrared irradiation device 14 was stopped after the heating step I. Heating step I is carried out for 8 hours out of 24 hours, and cooling step C is carried out for 16 hours out of 24 hours.

[0029] When the heating step I on the first day (first cycle) is started, the temperature of the upper surface 11a of the test piece 11 reaches the maximum temperature of 95°C in about 45 to 60 minutes. Thereafter, the maximum temperature is maintained until the end of the heating step I. When the cooling step C starts, the temperature of the upper surface 11a drops due to natural heat radiation, and eventually the temperature of the upper surface 11a becomes equal to room temperature. When the cooling step C on the first day is completed, the hardening step H on the second day (first cycle) begins. In Example 4, the hardening step H is carried out in three cycles (three days). In Example 5, the curing step H is carried out for 5 cycles (5 days).

[0030] Since the upper surface 11a (FIG. 1) of the test piece 11 is directly heated by infrared rays, the temperature of the test piece 11 decreases toward the lower surface 11b. The maximum temperature of the lower surface 11b in the heating step I is about 50°C.

[0031] The hardening process H is set based on the expected working hours at the construction site. For example, a worker starts the first cycle of heating process I at the start of work each day, and then stops the infrared irradiation device 14 and starts the cooling process C at the end of work eight hours later. Then, the worker starts the second cycle of heating process I at the start of work the next day.

[0032] Infrared heat curing can efficiently heat the geopolymer composition because the geopolymer composition is directly heated by the absorption of infrared rays emitted from the infrared irradiator 14, rather than by heat transfer through the air, such as convection in a thermostatic device. In addition, infrared heat curing does not require heating the air to heat the geopolymer composition, so heat curing can be performed quickly and safely.

[0033] In addition, in the first embodiment, the heat curing is performed using infrared rays with a short to medium wavelength of 500 to 1000 nm, which allows the infrared rays to penetrate the upper surface 11a effectively and reduces the reflection of the infrared rays on the upper surface 11a. Therefore, the geopolymer composition can be effectively heated by infrared rays.

[0034] Fig. 6 is a table showing the test results of Comparative Examples 1 and 2 and Examples 1 to 5. Fig. 7 is a graph showing the compressive strength of Comparative Examples 1 and 2 and Examples 1 to 5. The compressive strength test was carried out by compressing the test piece 11 in the axial direction. The compression test was carried out on the test piece cured for 7 days and the test piece cured for 28 days.

[0035] When the curing period was 28 days, Examples 1 to 5, which were heat-cured with infrared rays, and Comparative Example 2, which was heat-cured in a thermostatic device, had higher compressive strength than Comparative Example 1, which was cured at room temperature. When the curing period was 28 days, Example 1, which was heat-cured with infrared rays for 1 hour, achieved a compressive strength close to that of Comparative Example 2, which was heat-cured in a thermostatic device for 24 hours.

[0036] When the curing period was 28 days, Example 2, which was heat-cured with infrared rays for 4 hours, had a higher compressive strength than Comparative Example 2, which was heat-cured in a thermostatic device for 24 hours. Example 2 achieved a higher compressive strength than Comparative Example 2 with a heat curing time that was 1 / 6 of that of Comparative Example 2. In this way, heat curing using infrared rays can harden the geopolymer composition more effectively than heat curing using a constant temperature device.

[0037] When the curing period was 28 days, Example 3, which was heat-cured with infrared rays for 8 hours, had a higher compressive strength than Example 2, which was heat-cured with infrared rays for 4 hours. In this way, by extending the infrared heat curing time, the geopolymer composition can be hardened more effectively.

[0038] When the curing period was 28 days, Example 4, which underwent three cycles of 8-hour heat curing using infrared rays, and Example 5, which underwent five cycles of 8-hour heat curing using infrared rays, achieved higher compressive strength than Example 3, which underwent one cycle of 8-hour heat curing using infrared rays. In this way, by extending the infrared heat curing time, the geopolymer composition can be hardened more effectively.

[0039] When the curing period was 7 days, Examples 1 to 5, which were heat-cured using infrared light, had lower compressive strength than the Comparative Example, which was heat-cured in a thermostatic device for 24 hours. This is thought to be because, while heat-curing in a thermostatic device causes the entire test piece 11 to harden, heat-curing using infrared light does not sufficiently harden the portion of the test piece 11 on the underside 11b (FIG. 1). When the curing period was extended to 28 days, the test piece 11 hardened entirely, and the compressive strengths of Examples 2 to 5 were higher than that of Comparative Example 2, which was heat-cured in a thermostatic device.

[0040] <Second Example> FIG. 8 is a table showing the composition of each component in the second example in terms of mass ratio. In the second example, the active filler was a mixture of fly ash and blast furnace slag, and the relationship between the mixture ratio of fly ash and blast furnace slag and the compressive strength was investigated under curing conditions at room temperature. In Figure 8, (B) indicates active filler, (FA) indicates fly ash, (BFS) indicates blast furnace slag, (AAS) indicates alkaline activator, (AS1) indicates sodium hydroxide (NaOH), (AS2) indicates sodium silicate (Na2SiO3), and (W) indicates water.

[0041] The active filler (B) was a mixture of fly ash (FA) and blast furnace slag (BFS), and five different mixture ratios of fly ash (FA) were used: 0%, 50%, 65%, 80%, and 100%.

[0042] The alkaline activator (AAS) was a mixture of sodium hydroxide (AS1) and sodium silicate (AS2), with three different mixing ratios where the AS2 / AS1 values ​​were 1.5, 2.0, and 2.5.

[0043] In the second example, (AAS+W) / B is 0.5 and AAS / (AAS+W) is 0.5.

[0044] The test pieces of Examples 6 to 20 of the second example were cured at a room temperature of 20°C for 28 days.

[0045] Figure 9 is a graph showing the relationship between the mixture ratio of fly ash and blast furnace slag and compressive strength. For comparison, Figure 9 also shows the compressive strength of regular Portland cement. The W / C ratio of this Portland cement, which is the ratio of water (W) to cement (C), is 0.5.

[0046] Referring to FIG. 9, Examples 18 to 20, which contain 100% fly ash, have weaker compressive strength than Examples 6 to 8, which contain 100% blast furnace slag, regardless of the AAS ratio. When the fly ash content was between 0% and 65% (blast furnace slag content between 100% and 35%), the compressive strength was higher than that of Portland cement, regardless of the AAS ratio, and sufficient compressive strength was obtained. In particular, when the AAS ratio was 2.0 and 2.5, the compressive strength was highest at a mixture ratio of 50% fly ash (50% blast furnace slag). This indicates that a 1:1 mixture of fly ash and blast furnace slag as an active filler can achieve high compressive strength.

[0047] The second example was cured at room temperature, but it is believed that the same compressive strength trend as in the second example will be obtained even if the geopolymer composition of the second example is heated and cured using infrared rays from an infrared irradiation device. In other words, even when heat curing is performed using infrared rays, it is thought that high compressive strength can be obtained regardless of the AAS ratio when the fly ash content is 0% to 65% (blast furnace slag content is 100% to 35%). Furthermore, even in cases where sufficient compressive strength is not obtained by curing at room temperature and the fly ash content is 65% to 100%, it is believed that high compressive strength can be obtained by heat curing using infrared rays. Furthermore, even when heat curing is performed using infrared rays, it is thought that particularly high compressive strength can be obtained when the AAS ratio is 2.0 or 2.5 and the mixture ratio is 50% fly ash (50% blast furnace slag).

[0048] 10 is a diagram showing an infrared irradiation device 30 installed at a construction site where a geopolymer composition 20 is sprayed onto a slope S, which is the construction surface. The geopolymer composition 20 is sprayed onto the slope S by a sprayer (not shown). The geopolymer composition 20 may have the same composition as that of Example 1. The active filler of the geopolymer composition 20 may also be a mixture of fly ash and blast furnace slag. The construction site includes a ground surface G1, a step portion G2 located higher than the ground surface G1, and a sloped slope S connecting the ground surface G1 and the step portion G2.

[0049] 11 is a plan view of the infrared irradiating device 30 arranged on the slope S, viewed from above. FIG. 12 is a plan view illustrating the movement of the infrared irradiating device 30. The infrared irradiation device 30 includes an infrared irradiation unit 31 that irradiates infrared rays, and an irradiation unit support 32 that supports the infrared irradiation unit 31 so that the infrared irradiation unit 31 faces the geopolymer composition 20 on the slope S.

[0050] The irradiation unit support 32 comprises a lower frame 32a installed on the ground G1, an upper frame 32b installed on the step G2, and a moving unit 32c provided at the lower end of the lower frame 32a and the lower end of the upper frame 32b, respectively. The infrared irradiating unit 31 extends vertically along the slope S and connects the lower frame 32a and the upper frame 32b. The infrared irradiation device 30 is configured by connecting a plurality of units (five in FIG. 11) each including an infrared irradiation section 31 and an irradiation section support 32 in the horizontal direction. The moving portion 32c enables the infrared irradiating device 30 to be moved, and is, for example, a wheel that comes into contact with the ground G1 and the step portion G2.

[0051] The lower surface of the infrared irradiation unit 31 is an irradiation surface 31a that irradiates infrared rays onto the geopolymer composition 20 on the slope S. The irradiation surface 31a is arranged parallel to the slope S and faces the geopolymer composition 20. The irradiation surface 31a is arranged at a predetermined distance from the geopolymer composition 20. The infrared irradiating device 30 irradiates infrared rays using power supplied from, for example, a solar power generation device installed at the construction site. The wavelength of the infrared rays emitted by the infrared irradiating device 30 is 500 to 1000 nm.

[0052] 12, the slope S is longer than the width of the infrared irradiating device 30. The imaginary line frame shown in FIGS. The infrared irradiation device 30 moves laterally (left and right) relative to the slope S as shown by the arrow in Figure 12, heat-curing the geopolymer composition 20 on the entire slope S to form a hardened geopolymer body.

[0053] As an example, the infrared irradiation device 30 performs infrared heat curing starting from the first construction section S1 at the left end of the slope S in Figure 12. After completing heat curing in the first construction section S1 for, for example, 8 hours, the infrared irradiation device 30 moves to the second construction section S2, which is adjacent to the right of the first construction section S1, by the moving section 32c, and performs infrared heat curing on the geopolymer composition 20 in the second construction section S2. Thereafter, the infrared irradiation device 30 moves in order to the third construction section S3 and the fourth construction section S4, which are on the right side of the second construction section S2, and performs infrared heat curing. When the infrared irradiation device 30 is moved by the moving part 32c, it moves along the slope S and the geopolymer composition 20 while maintaining the distance between the irradiation surface 31a and the geopolymer composition 20 at a predetermined distance. The infrared irradiating device 30 may be moved up and down relative to a slope that is long in the vertical direction to perform heat curing using infrared rays.

[0054] As shown in Figure 5, the geopolymer composition 20 can be subjected to a hardening process H multiple times in one cycle per day, which includes a heating process I in which infrared rays are irradiated by an infrared irradiation device 30, and a cooling process C in which the infrared irradiation by the infrared irradiation device 30 is stopped after the heating process I.

[0055] As described above, according to an embodiment of the present invention, the method for applying a geopolymer hardened body is a method for applying a geopolymer hardened body by hardening a geopolymer composition 20 sprayed onto a slope S, which is the application surface, to form a geopolymer hardened body, and the geopolymer composition 20 is heated by infrared rays irradiated by an infrared irradiation device 30. According to this method, the infrared rays emitted by the infrared irradiation device 30 are directly absorbed by the surface of the geopolymer composition 20, thereby heating the geopolymer composition 20. Therefore, the geopolymer composition 20 sprayed onto the slope S can be effectively heated and cured by the infrared rays.

[0056] In addition, in this construction method, a hardening process H is performed multiple times, which is a cycle of a heating process I in which infrared rays are irradiated by the infrared irradiation device 30 and a cooling process C in which the irradiation of infrared rays by the infrared irradiation device 30 is stopped after the heating process I. According to this method, even if it is not possible to irradiate infrared rays continuously for a long period of time due to constraints on working hours, the curing process H, which performs the heating process I and the cooling process C in one cycle, can be performed multiple times to extend the infrared irradiation time, and the geopolymer composition 20 sprayed onto the slope S can be effectively heat-cured.

[0057] Moreover, the infrared radiation from the infrared radiation device 30 is continuously radiated for one hour or more. In this case, by continuously irradiating the geopolymer composition 20 with infrared rays for one hour or more, the geopolymer composition 20 can be sufficiently heated, and the geopolymer composition 20 can be effectively heat-cured by the infrared rays.

[0058] Furthermore, the wavelength of the infrared light is 500 to 1000 nm. In this case, infrared rays with a wavelength of 500 to 1000 nm can penetrate deeply into the geopolymer composition 20, so that the geopolymer composition 20 can be effectively heat-cured by the infrared rays.

[0059] The geopolymer composition 20 also includes fly ash as an active filler. In this case, the geopolymer composition 20 containing fly ash as an active filler can be effectively heat-cured by infrared radiation. The active filler can be fly ash (lime coal), blast furnace slag, metakaolin, volcanic ash, or a mixture thereof.

[0060] The infrared irradiation device 30 comprises an infrared irradiation unit 31 that irradiates infrared rays onto the geopolymer composition 20 sprayed onto the slope S, which is the construction surface, and an irradiation unit support 32 that supports the infrared irradiation unit 31 at the spraying construction site, and the irradiation unit support 32 supports the infrared irradiation unit 31 so that the infrared irradiation surface 31a of the infrared irradiation unit 31 faces the slope S. According to this configuration, the infrared irradiation surface 31a of the infrared irradiation unit 31 can be made to face the slope S at the spraying construction site, so that infrared rays can be efficiently irradiated onto the geopolymer composition 20 on the slope S, and the geopolymer composition 20 can be effectively heated and cured by the infrared rays.

[0061] The irradiation unit support 32 also includes a moving portion 32c that allows the irradiation surface 31a to move along the slope S. According to this configuration, the moving part 32c of the irradiation unit support 32 allows the irradiation surface 31a to be moved along the slope S, so that by moving the irradiation surface 31a sequentially along the large slope S, the geopolymer composition 20 sprayed onto the wide slope S can be effectively heated and cured by infrared rays.

[0062] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and unless otherwise limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the configurations of the above-described embodiment may be added or deleted as appropriate, and the configurations of one embodiment may be incorporated into other embodiments. Furthermore, the effects of the above-described embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-described effects. In the above embodiment, the slope S is used as an example of the construction surface, but the present invention is not limited to this. The construction surface to which the geopolymer composition is sprayed and cured by the infrared irradiation device may be the wall surface of a tunnel structure or the wall surface of a building. Furthermore, in the above embodiment, the irradiation surface 31a can be moved by moving the infrared irradiation device 30 using the moving unit 32c, which is a wheel provided on the irradiation unit support 32, but the present invention is not limited to this. For example, the moving unit may be a slide mechanism configured with a rail structure or the like that enables relative movement of the irradiation surface 31a with respect to the irradiation unit support 32. In this case, the infrared irradiation unit 31 slides on the irradiation unit support 32 using the slide mechanism, and the irradiation surface 31a moves along the slope S. [Explanation of symbols]

[0063] 20: Geopolymer composition 30: Infrared irradiation device 31: Infrared irradiation unit 31a: Irradiation surface 32: Irradiation part support 32c: Moving part S: Slope (construction surface) C: Cooling process H: Hardening process I:Heating process

Claims

1. A method for applying a geopolymer hardened body by hardening a geopolymer composition sprayed on a construction surface to form a geopolymer hardened body, A method for constructing a hardened geopolymer body, in which the geopolymer composition is heated by infrared rays irradiated by an infrared irradiation device.

2. 2. The construction method of claim 1, wherein a curing process is performed multiple times in one cycle, the heating process being performed by the infrared irradiation device to irradiate infrared rays and the cooling process being performed by stopping the irradiation of infrared rays by the infrared irradiation device after the heating process.

3. The method for constructing a geopolymer hardened body according to claim 1, wherein the infrared rays from the infrared irradiation device are continuously irradiated for one hour or more.

4. The method for constructing a geopolymer hardened body according to claim 1, wherein the wavelength of the infrared light is 500 to 1000 nm.

5. The method for constructing a geopolymer hardened body according to any one of claims 1 to 4, wherein the geopolymer composition contains at least one of fly ash and blast furnace slag as an active filler.

6. An infrared irradiation unit that irradiates infrared rays onto the geopolymer composition sprayed on the construction surface, and an irradiation unit support that supports the infrared irradiation unit at the spraying construction site, The irradiation unit support supports the infrared irradiation unit so that the infrared irradiation surface of the infrared irradiation unit faces the construction surface.

7. The infrared irradiation device according to claim 6 , wherein the irradiation unit support includes a moving unit that enables the irradiation surface to move along the construction surface.

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