Method for manufacturing cement hardened bodies for carbon dioxide fixation

Abstract

The present invention provides a method for manufacturing a cement hardened body for carbon dioxide fixation, which allows for the easy production of a cement hardened body with a carbon dioxide absorbing liquid applied to its surface. [Solution] The method includes a lamination step of forming a cement-hardened body 2 by laminating cement-based material 21 in an additive manufacturing apparatus 4, and a carbon dioxide absorbent coating step of applying a carbon dioxide absorbent liquid 3 containing a carbon dioxide absorbent to the surface of the cement-hardened body 2.

Description

Technical Field

[0001] The present invention relates to a method for producing a cement hardened body for carbon dioxide fixation.

Background Art

[0002] There is a technique for promoting the absorption and fixation of CO2 in the atmosphere by concrete structures by applying a carbon dioxide absorption liquid that promotes the absorption of CO2, such as an amine compound, to the surface layer of the concrete structure (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When manufacturing such a concrete structure, a carbon dioxide absorption liquid is applied to the surface layer of the hardened concrete structure. In order to penetrate the carbon dioxide absorption liquid into the inside of the structure, it is necessary to apply the carbon dioxide absorption liquid to the surface layer of the concrete structure in multiple steps. Therefore, when applying the carbon dioxide absorption liquid to a newly constructed concrete structure, it is necessary to pour the concrete material into the formwork of the concrete structure, remove the formwork, and then apply the carbon dioxide absorption liquid to the surface layer of the concrete structure with a brush or the like, which is laborious.

[0005] Therefore, an object of the present invention is to provide a method for producing a cement hardened body for carbon dioxide fixation that can easily produce a cement hardened body (concrete structure) having a carbon dioxide absorption liquid applied to its surface.

Means for Solving the Problems

[0006] To achieve the above objective, the method for manufacturing a cement hardened body for carbon dioxide fixation according to the present invention comprises a lamination step of forming a cement hardened body by laminating cement-based materials in an additive manufacturing apparatus, and a carbon dioxide absorbent liquid coating step of applying a carbon dioxide absorbent liquid containing a carbon dioxide absorbent to the surface of the cement hardened body.

[0007] In this invention, by forming a cement-hardened body by laminating cement-based materials using an additive manufacturing apparatus, unlike conventional methods of constructing cement-hardened bodies using formwork, it is possible to apply the carbon dioxide absorbing liquid to the surface of the cement-hardened body at almost the same time as the cement-hardened body is formed, without waiting for the curing period of the cement-hardened body. Furthermore, since the carbon dioxide absorbing liquid can be applied each time a predetermined amount of cement-based material is laminated using the additive manufacturing apparatus, the construction period can be shortened compared to applying the carbon dioxide absorbing liquid after the entire cement-hardened body has been formed. As a result, a cement-hardened body for carbon dioxide fixation with the carbon dioxide absorbing liquid applied to its surface can be easily manufactured.

[0008] Furthermore, in the method for manufacturing a cement hardened body for carbon dioxide fixation according to the present invention, in the carbon dioxide absorbent liquid coating step, the carbon dioxide absorbent liquid may be sprayed onto the surface of the cement hardened body using a spraying device.

[0009] By using this configuration, cement hardened bodies for carbon dioxide fixation can be easily manufactured by operating an additive manufacturing device that shapes the cement hardened body and a spraying device that sprays a carbon dioxide absorbing liquid onto the surface of the cement hardened body.

[0010] Furthermore, in the method for manufacturing a cement hardened body for carbon dioxide fixation according to the present invention, in the carbon dioxide absorbent liquid coating step, the carbon dioxide absorbent liquid may be applied to the surface of the cement hardened body using a coating device.

[0011] By using this configuration, cement hardened bodies for carbon dioxide fixation can be easily manufactured by operating an additive manufacturing apparatus for forming cement hardened bodies and a coating apparatus for applying carbon dioxide absorbing liquid to the surface of the cement hardened bodies.

[0012] Furthermore, in the method for manufacturing a cement hardened body for carbon dioxide fixation according to the present invention, irregularities may be formed on the surface of the cement hardened body during the lamination step.

[0013] This configuration increases the surface area of ​​the hardened cement, allowing more carbon dioxide absorbent liquid to be applied to the surface of the hardened cement. [Effects of the Invention]

[0014] According to the present invention, a cement hardened body coated with a carbon dioxide absorbing liquid on its surface can be easily manufactured. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing a method for manufacturing a cement hardened body for carbon dioxide fixation according to an embodiment of the present invention. [Figure 2] This is a front view showing a method for manufacturing a cement hardened body for carbon dioxide fixation according to an embodiment of the present invention. [Figure 3] This image shows an example of a side view of a hardened cement body. [Figure 4] This is a diagram showing the nozzle's discharge opening. [Figure 5] This figure shows a cement hardened body formed by layers of cement-based material discharged from the discharge port shown in Figure 4. [Figure 6] This diagram shows a method for manufacturing a cement hardened body for carbon dioxide fixation, which involves applying a carbon dioxide absorbent solution using a coating device. [Figure 7] This diagram shows a method for manufacturing a cement hardened body for carbon dioxide fixation, in which an additive manufacturing device and a spraying device move simultaneously. [Figure 8]FIG. 0 is a diagram showing a method for manufacturing a cement hardened body for carbon dioxide fixation using a material jetting type additive manufacturing apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] Hereinafter, a method for manufacturing a cement hardened body for carbon dioxide fixation according to an embodiment of the present invention will be described based on FIGS. 1 to 5. As shown in FIGS. 1 and 2, the cement hardened body 1 for carbon dioxide fixation is a member on the surface of a cement hardened body 2 obtained by hardening a cementitious material 21, on which a carbon dioxide absorbing liquid 3 containing a carbon dioxide absorbent that absorbs and fixes CO2 in the atmosphere is applied.

[0017] The cement hardened body 2 is formed by laminating a cementitious material 21 using an additive manufacturing apparatus 4 such as a 3D printer. The additive manufacturing apparatus 4 shown in FIGS. 1 and 2 shows a nozzle 41 and omits other illustrations. The additive manufacturing apparatus 4 of the present embodiment is a material extrusion type apparatus that extrudes and discharges a cementitious material 21. The cementitious material 21 includes cement paste, mortar, concrete, and the like. Various short fibers may be added to the cementitious material 21. The types of short fibers to be added are fibers made of chemically synthesized polymers or fibers made of inorganic substances. Examples of the former include polypropylene fibers, polyvinyl alcohol fibers, polyethylene fibers, polyester fibers, aramid fibers, and the like. Examples of the latter include glass fibers, steel fibers, carbon fibers, rock fibers (such as basalt), ceramic fibers, silica fibers, and the like.

[0018] The carbon dioxide absorbing liquid 3 is applied to the surface of the cement hardened body 2 by a spraying device 5 that sprays and blows the carbon dioxide absorbing liquid 3. The spraying device 5 shown in FIGS. 1 and 2 shows a spraying nozzle 51 for spraying the carbon dioxide absorbing liquid 3 and a supply hose for supplying the carbon dioxide absorbing liquid 3 to the spraying nozzle 51, and omits other illustrations. Since the carbon dioxide absorbent is applied to the cementitious material 21 containing a large amount of fresh water in the non-hardened state, a hydrophilic material is preferable.

[0019] The manufacturing method of the cement hardened body 1 for carbon dioxide immobilization first shapes the cement hardened body 2 by laminating the cement-based material 21 with an additive manufacturing apparatus 4 (lamination step). Using a material injection type additive manufacturing apparatus 4, the cement-based material 21 may be injected and laminated onto a reinforcing material such as a reinforcing bar.

[0020] In the lamination step, concavities and convexities may be formed on the surface of the cement hardened body 2. By doing so, the surface area of the surface of the cement hardened body 2 that contacts the atmosphere can be increased. As a result, the cement hardened body 1 for carbon dioxide immobilization with the carbon dioxide absorption liquid 3 applied to the surface easily absorbs a large amount of CO2 from the surface layer. The concavities and convexities on the surface layer of the cement hardened body 2 are formed, for example, as follows (1) to (3). (1) Since concavities and convexities are formed between the layers 22, 22 of the cement-based material 21 to be laminated (between layers), the height dimension per layer to be laminated is reduced. For example, the height dimension per layer is set to 30 mm or less. (2) The movement path of the nozzle 41 of the additive manufacturing apparatus 4 is made into a wavy path instead of a straight path, and concavities and convexities are formed in the layers 22 of the cement-based material 21 to be laminated and between the layers as shown in FIG. 3. (3) As shown in FIG. 4, the discharge port 41a of the nozzle 41 of the additive manufacturing apparatus 4 is made trapezoidal, and as shown in FIG. 5, the cross-sectional shape of the layer 22 of the cement-based material 21 to be laminated is made trapezoidal. By increasing the difference between the width dimension of the upper surface 221 and the width dimension of the lower surface 222 of the layer 22 of the cement-based material 21, the concavities and convexities between the laminated layers are increased.

[0021] Next, the carbon dioxide absorbent liquid 3 is applied to the surface of the cement hardened body 2 that has been laminated in the lamination process (carbon dioxide absorbent liquid application process). As described above, the carbon dioxide absorbent liquid application process involves spraying the carbon dioxide absorbent liquid 3 onto the entire surface of the cement hardened body 2 using a spraying device 5. The carbon dioxide absorbent liquid application process may also be performed by spraying the carbon dioxide absorbent liquid 3 onto the cement-based material 21 that has been discharged from the nozzle 41 of the additive manufacturing device 4 at the same time as the cement-based material 21 has been discharged in the lamination process. Alternatively, the carbon dioxide absorbent liquid application process may be performed by spraying the carbon dioxide absorbent liquid 3 onto the layer 22 of the laminated cement-based material 21 each time a predetermined amount of cement-based material 21 has been laminated in the lamination process (for example, every layer), or by spraying the carbon dioxide absorbent liquid 3 onto the surface of the cement hardened body 2 after the lamination process has been completed.

[0022] Preferably, the spraying device 5 is equipped with a pump that can adjust the amount of carbon dioxide absorbent liquid 3 to be pumped. For example, by pumping a fixed amount of carbon dioxide absorbent liquid 3, it becomes easier to control the amount of carbon dioxide absorbent liquid 3 applied.

[0023] When a carbon dioxide absorbent liquid 3, which uses an amine compound as a carbon dioxide absorbent, is added to a cement-based material 21 before it sets, the cement-based material 21 may exhibit a behavior of rapid setting (pseudo-setting effect). By utilizing this property, it is also possible to enhance the lamination capabilities of the additive manufacturing apparatus 4. The method for manufacturing a carbon dioxide-fixing cement hardened body in this embodiment is a method of additive manufacturing by stacking fresh, unhardened cement-based material 21 layer by layer. As a result, the stacked cement-based material 21 deforms vertically due to its own weight from the upper layers. By applying a carbon dioxide absorbent liquid 3, which mainly consists of an amine compound, to the side surface of the cement-based material 21, stiffness can be formed on the surface of the cement-based material 21, improving the shape retention and self-supporting ability of the cement-based material 21. This makes it possible to fabricate shapes with overhangs using the additive manufacturing apparatus 4. An example of an amine compound that produces a pseudo-setting effect is MDEA (Methyldiethanolamine).

[0024] Since carbon dioxide absorbent solution 3 can be handled stably even when CO2 is intentionally dissolved in it (for example, 40% by amine mass ratio), it is also possible to apply the carbon dioxide absorbent solution with CO2 dissolved in it beforehand.

[0025] Next, the operation and effects of the method for producing a cement hardened body for carbon dioxide fixation according to this embodiment will be described. In the method for manufacturing a cement hardened body for carbon dioxide fixation according to this embodiment, by forming a cement hardened body 2 by laminating cement-based material 21 in an additive manufacturing device 4, unlike the conventional method of constructing a cement hardened body using a formwork, it is possible to apply the carbon dioxide absorbing liquid 3 to the surface of the cement hardened body 2 at almost the same time as the cement hardened body 2 is formed, without waiting for the curing period of the cement hardened body 2. Furthermore, by applying the carbon dioxide absorbing liquid 3 each time a predetermined amount of cement-based material 21 is laminated in the additive manufacturing device 4, the construction period can be shortened compared to applying the carbon dioxide absorbing liquid 3 after the entire cement hardened body 2 has been formed. As a result, a cement hardened body 1 for carbon dioxide fixation with the carbon dioxide absorbing liquid 3 applied to its surface can be easily manufactured.

[0026] Furthermore, in the carbon dioxide absorbent coating process, the carbon dioxide absorbent liquid 3 is sprayed onto the surface of the cement hardened body 2 using a spraying device 5. With this configuration, the cement hardened body 1 for carbon dioxide fixation can be easily manufactured by operating the additive manufacturing device 4 that shapes the cement hardened body 2 and the spraying device 5 that sprays the carbon dioxide absorbent liquid 3 onto the surface of the cement hardened body 2.

[0027] Furthermore, during the lamination process, irregularities are formed on the surface of the cement hardened body 2. This configuration increases the surface area of ​​the cement hardened body 2, allowing more carbon dioxide absorbent liquid 3 to be applied to its surface.

[0028] Although embodiments of the method for manufacturing a cement hardened body for carbon dioxide fixation according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, as shown in Figure 6, in the carbon dioxide absorbent coating step, the carbon dioxide absorbent 3 may be applied to the surface of the cement hardened body 2 using a coating device 6. With this configuration, the cement hardened body 1 for carbon dioxide fixation can be easily manufactured by operating the additive manufacturing device 4 that forms the cement hardened body 2 and the coating device 6 that applies the carbon dioxide absorbent 3 to the surface of the cement hardened body 2. The coating device 6 shown in Figure 6 illustrates a brush 61 for applying the carbon dioxide absorbent 3 and a supply hose 62 for supplying the carbon dioxide absorbent 3 to the brush 61, but other parts are omitted from the illustration.

[0029] In the above embodiment, irregularities are formed on the surface of the cement hardened body 2 during the lamination process, but the surface of the cement hardened body 2 may be a flat surface or a smooth curved surface, etc.

[0030] In the above embodiment, the spray nozzle 51 of the spraying device 5 and the nozzle 41 of the additive manufacturing device 4 are connected to separate robots or the like, and the spraying device 5 and the additive manufacturing device 4 are controlled independently. In contrast, as shown in Figure 7, the spray nozzle 51 of the spraying device 5 may be connected near the nozzle 41 of the additive manufacturing device 4, and the additive manufacturing device 4 and the spraying device 5 may be controlled to spray the carbon dioxide absorption liquid 3 onto the surface of the cement-based material 21 discharged from the spray nozzle 51 while simultaneously moving the spray nozzle 51 of the spraying device 5 and the nozzle 41 of the additive manufacturing device 4.

[0031] In the above embodiment, the additive manufacturing apparatus 4 is a material extrusion type apparatus that extrudes and discharges the cement-based material 21. However, as shown in Figure 8, it may also be a material injection type apparatus having an injection nozzle 71 that sprays and discharges the cement-based material 21, as in the additive manufacturing apparatus 7.

[0032] Simultaneously with the discharge of the cement-based material 21 by the additive manufacturing apparatus 4, the carbon dioxide absorbent liquid 3 may be applied not only to the sides of the discharged cement-based material 21 but also to its top surface. This allows the carbon dioxide absorbent liquid 3 to be impregnated into the interior of the hardened cement body 2, further increasing the penetration depth. If the cement hardened body 1 for carbon dioxide fixation to be manufactured is a formwork, the carbon dioxide absorbent liquid 3 may be applied only to the surface that comes into contact with the atmosphere during use. However, by also applying the carbon dioxide absorbent liquid 3 to the surface that does not come into contact with the atmosphere (the side into which concrete is poured), the carbon dioxide absorbent liquid 3 can be impregnated into the interior of the cement hardened body 2.

[0033] The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the UN Summit in September 2015. The method for manufacturing a cement hardened body for carbon dioxide fixation according to this embodiment can contribute to achieving goals such as "Goal 9: Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," among the 17 Sustainable Development Goals (SDGs). [Explanation of Symbols]

[0034] 1. Cement hardened body for carbon dioxide fixation 2. Cement hardened body 3. Carbon dioxide absorbent solution 4,7 Additive manufacturing equipment 5. Spraying device 6. Coating device 21. Cement-based materials

Claims

1. A lamination process in which cement-based materials are layered using additive manufacturing equipment to form a cemented hardened body, A method for manufacturing a cementite for carbon dioxide fixation, comprising a step of applying a carbon dioxide absorbent solution containing a carbon dioxide absorbent to the surface of the cementite.

2. The method for manufacturing a cement hardened body for carbon dioxide fixation according to claim 1, wherein in the carbon dioxide absorbent coating step, the carbon dioxide absorbent is sprayed onto the surface of the cement hardened body using a spraying device.

3. The method for manufacturing a cement hardened body for carbon dioxide fixation according to claim 1, wherein in the carbon dioxide absorbent coating step, the carbon dioxide absorbent is applied to the surface of the cement hardened body using a coating device.

4. A method for manufacturing a cementite for carbon dioxide fixation according to any one of claims 1 to 3, wherein the lamination step involves forming irregularities on the surface of the cementite.

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