Manufacturing method of tabular concrete member and tabular concrete member

Abstract

To provide a tabular concrete member with which work labor of leveling with a trowel can be alleviated and warpage can be regulated, and a manufacturing method thereof.SOLUTION: A tabular concrete member 1 includes: a first layer plate 11 of a front side made of a first flowable material containing aggregate, a thickening material, and water, the first flowable material having already been cured with time course; and a second layer plate 12 of a rear side made of a second flowable material having higher fluidity than the first flowable material, the second flowable material having already been cured with time course. When the tabular concrete member 1 is manufactured, the first flowable material is cast into a formwork, and, in a stage where a cold joint does not occur while the first flowable material is being cured, the second flowable material is cast onto the first flowable material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a plate-shaped concrete member used as an exterior wall surface material, etc., and a method for manufacturing the same. [Background technology]

[0002] Patent Document 1 discloses a structure that includes a concrete wall body made of a large number of lightweight aggregates and mortar containing the lightweight aggregates, and tiles adhered to its surface, in which the concrete wall body has the lightweight aggregates unevenly distributed on its back side and the mortar unevenly distributed on its front side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-234715 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when aggregate rises above the concrete surface, there is a problem that it takes a lot of work to level the concrete surface with a trowel. Also, in a structure with tiles on the surface, there is a difference in the degree of evaporation of water from the concrete between the front side and the back side, which causes the concrete body to warp.

[0005] An object of the present invention is to provide a plate-shaped concrete member that can reduce the labor required for leveling with a trowel and suppress warping, and a method for manufacturing the same. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the manufacturing method of the plate-shaped concrete member of the present invention is a manufacturing method of a plate-shaped concrete member comprising a first layer on the front side in which a first fluidity material containing aggregate, hardening material and water has hardened over time, and a second layer on the back side in which a second fluidity material containing aggregate, hardening material and water and having a higher fluidity than the first fluidity material has hardened over time, characterized in that the first fluidity material is poured into a formwork, and the second fluidity material is poured on top of the first fluidity material while the first fluidity material is hardening and does not cause cold joints.

[0007] With the above method, even if the aggregate floats up from the surface of the concrete during the hardening of the first fluidity material which becomes the first layer, the second fluidity material which becomes the second layer is poured on top of the first layer, eliminating the need for smoothing the surface of the first fluidity material, and the surface of the second fluidity material (the back side of the plate-shaped concrete member) is treated with the second fluidity material which has a higher fluidity than the first fluidity material, thereby reducing the effort required for smoothing with a trowel.

[0008] In the above method for manufacturing a plate-shaped concrete member, a decorative member may be laid on the bottom surface of the formwork, and the first fluid material may be poured into the formwork. This allows the production of a plate-shaped concrete member having a decorative member on the surface of the first layer. Here, if a decorative member is present on the surface of the first layer, evaporation of water from the surface side of the first layer is suppressed, but if evaporation of water from the back side of the first layer is not suppressed, warping of the plate-shaped concrete member is induced. As described above, if the second layer is present, evaporation of water from the back side of the first layer is suppressed, so that even if a decorative member is present on the surface of the first layer, the difference in the degree of evaporation of water between the surface side and the back side of the first layer can be reduced, and warping of the plate-shaped concrete member can be suppressed.

[0009] In the method for manufacturing the plate-shaped concrete member, the second fluidity material may be richer in hardening material than the first fluidity material. This improves the strength of the second layer. Furthermore, the rich blending as described above can further suppress evaporation of water from the back surface of the first layer.

[0010] In the above-mentioned method for manufacturing a plate-shaped concrete member, the first fluid material may be ready-mixed concrete in which the hardening material is cement, and the second fluid material may be mortar paste in which the hardening material is cement.

[0011] In addition, the plate-shaped concrete member of the present invention is characterized by having a first layer portion on the front side in which a first fluid material containing aggregate, hardening material and water has hardened over time, and a second layer portion on the back side in which a second fluid material containing aggregate, hardening material and water and having a higher fluidity than the first fluid material has hardened over time.

[0012] With the above configuration, in the production of the plate-shaped concrete member, the work of leveling the first fluid material with a trowel can be eliminated, thereby improving the efficiency of production.

[0013] The plate-shaped concrete member may be provided with a decorative member on a surface of the first layer.

[0014] In the plate-shaped concrete member, the second fluidity material may be richer in the hardening material than the first fluidity material.

[0015] In the plate-shaped concrete member, the first fluid material may be ready-mixed concrete in which the hardening material is cement, and the second fluid material may be mortar paste in which the hardening material is cement. Effect of the Invention

[0016] The present invention has the effect of reducing the labor required for smoothing with a trowel when manufacturing plate-shaped concrete members, and also suppressing warping of the plate-shaped concrete members. [Brief description of the drawings]

[0017] [Figure 1] 2 is an explanatory diagram of a longitudinal cross-sectional view of a portion of a plate-shaped concrete member according to an embodiment. FIG. [Diagram 2] FIG. 2 is an explanatory diagram showing a first layer and a second layer in the plate-shaped concrete member of the embodiment. [Diagram 3] 1 is a graph showing the degree of warping over time in a plate-shaped concrete member of an embodiment. [Figure 4] 4 is an explanatory diagram showing a manufacturing method of a plate-shaped concrete member according to an embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. As shown in Fig. 1, a plate-shaped concrete member 1 includes a first layer 11 on the front side where fresh concrete, which is a first fluidity material, has hardened over time, a second layer 12 on the back side where mortar paste, which is a second fluidity material having a higher fluidity than the first fluidity material, has hardened over time, and reinforcement 13. In this embodiment, the plate-shaped concrete member 1 is a precast curtain wall and includes a decorative member 14 made of tiles, stone, or the like on the surface of the first layer 11.

[0019] In this plate-shaped concrete member 1, the plate thickness of the plate portion excluding the decorative members 14 is 100 mm, the thickness of the first layer 11 is 90 mm, and the thickness of the second layer 12 is 10 mm. The reinforcing bars 13 are single and are arranged toward the center of the plate portion excluding the decorative members 14 in the plate thickness direction.

[0020] 2, the first layer 11 (first fluid material) contains coarse aggregate M1, fine aggregate M2 having a particle size smaller than that of the coarse aggregate M1, and a hardening material, cement S. On the other hand, the second layer 12 (second fluid material) does not contain coarse aggregate M1, but contains fine aggregate M2 and cement S.

[0021] The first layer 11 contains, for example, an artificial or natural lightweight coarse aggregate as the coarse aggregate M1, an artificial or natural lightweight fine aggregate as the fine aggregate M2, and cement S at 250 to 350 kg / m 3 Standard mix concrete with density of 500-600×10 -6 In this embodiment, the first layer portion 11 is made of a material having resin fibers (fibrous reinforcing material) mixed therein.

[0022] The second layer 12 contains artificial or natural lightweight fine aggregate as fine aggregate M2, and cement S at 350 to 450 kg / m 3 The second layer 12 is made of a mortar having a density of 1000 to 2000 mm. ...

[0023] Next, an accelerated warping test was carried out on the above-mentioned plate-shaped concrete member 1, and the results are shown below. The comparative concrete member used for comparison does not have the second layer 12, and the entire plate portion excluding the decorative member 14 is composed of only the first layer 11.

[0024] Table 1 shows detailed specifications of the plate-shaped concrete member 1 and the above-mentioned comparative concrete member.

[0025] 3 is a graph showing the number of days elapsed since forced drying on the horizontal axis and the warpage value (mm) on the vertical axis. The forced drying temperature was 80°C.

[0026] [Table 1]

[0027] As shown in the graph of Figure 3, the warpage value of the comparative concrete member after 35 days was 4.3 mm, while the warpage value of the plate-shaped concrete member 1 after 35 days was 3.8 mm. In other words, the warpage of the plate-shaped concrete member 1 was reduced by about 10% compared to the comparative concrete member.

[0028] Next, a description will be given of a manufacturing method for the plate-shaped concrete member 1. As shown in Fig. 4, a decorative member 14 is placed at the bottom inside a formwork 5 having an inner shape that matches the outer shape of a curtain wall or the like, and further, the reinforcing bars 13 are placed so as to be floating relative to the decorative member 14.

[0029] Then, ready mixed concrete (first fluid material) containing coarse aggregate M1 and fine aggregate M2 to become the first layer 11 is poured into the formwork 5. The pouring thickness is 90 mm, which corresponds to the thickness of the first layer 11. After pouring, the elapsed time is measured, and mortar paste containing fine aggregate M2 to become the second layer 12 is poured on the first layer 11 at a timing that does not cause cold joints, during hardening (setting) after the ready mixed concrete has hardened to a certain extent, taking into consideration the ambient air temperature. The pouring thickness is 10 mm, which corresponds to the thickness of the second layer 12. The plate-shaped concrete member 1 is manufactured by preparing ready mixed concrete and mortar paste in a factory, and is not necessarily poured in layers due to a delay in the arrival of an agitator truck, etc., and from the viewpoint of speeding up the manufacturing of the plate-shaped concrete member 1, it is desirable to quickly pour the mortar paste when the ready mixed concrete has hardened to such an extent that it does not deform when poured.

[0030] With the above manufacturing method, even if coarse aggregate M1 rises above the surface of the concrete that will become the first layer 11 while the concrete is hardening within the formwork 5, mortar paste that will become the second layer 12 is poured onto the first layer 11, eliminating the need to smooth the surface of the concrete that will become the first layer 11.The surface of the second layer 12 (the back side of the plate-shaped concrete member 1) is treated with the mortar paste, reducing the effort required for smoothing with a trowel.

[0031] Furthermore, as described above, by laying the decorative member 14 on the bottom surface of the formwork 5 and pouring ready mixed concrete to become the first layer 11 into the formwork 5, it is possible to produce a plate-shaped concrete member 1 having the decorative member 14 on the surface of the first layer 11. Furthermore, since the evaporation of water from the back surface of the first layer 11 is suppressed by the second layer 12, even if the decorative member 14 is present on the surface of the first layer 11, the difference in the degree of evaporation of water from the concrete between the front surface and back surface of the plate-shaped concrete member 1 is reduced, and warping of the plate-shaped concrete member 1 can be suppressed as shown in FIG. 3.

[0032] In the above embodiment, the cement S of the mortar that becomes the second ply portion 12 is set to 350 to 450 kg / m 3 The strength of the second layer 12 is also improved because the cement density of the second layer 12 is high. Furthermore, the evaporation of water from the back side of the first layer 11 is suppressed compared to the standard mix. The cement density of the second layer 12 is preferably higher than that of the first layer 11, but it is preferable that the second layer 12 contains cement S at a density of 350 to 450 kg / m. 3 The density of the material is not limited to 100%.

[0033] In addition, the first layer 11 and the second layer 12 contain lightweight aggregate, but may contain normal aggregate. The first layer 11 may be foamed to reduce its weight. The first layer 11 and the second layer 12 may not contain fibrous reinforcement. Alternatively, the first layer 11 may not contain fibrous reinforcement, and the second layer 12 may contain short fibrous reinforcement from the viewpoint of improving strength. By making the material composition of the first fluid material that constitutes the first layer 11 and the material composition of the second fluid material that constitutes the second layer 12 as common as possible, the manufacture of the plate-shaped concrete member 1 can be simplified. In addition, a primer layer (adhesion promoting layer) that improves the adhesion (adhesion) between the first layer 11 and the second layer 12 may be provided. The primer layer may be made of a resin formulation, but is not limited to a resin formulation. The primer layer is preferably applied to the entire surface of the first layer plate portion 11, but is not limited to being applied to the entire surface.

[0034] Furthermore, in this embodiment, an example has been shown in which the plate-shaped concrete member 1 is a precast curtain wall, but the present invention is not limited to this, and the plate-shaped concrete member 1 may be a precast floor panel.

[0035] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same scope as the present invention or within an equivalent scope. [Explanation of symbols]

[0036] 1: Plate-shaped concrete member 5: Formwork 11: 1st layer plate part 12: 2nd layer plate part 13: Reinforcement 14: Decorative materials M1: Coarse aggregate M2: Fine aggregate S: Cement

Claims

1. A method for manufacturing a plate-shaped concrete member comprising a first layer on the front side in which a first fluidity material containing aggregate, hardening material and water has hardened over time, and a second layer on the back side in which a second fluidity material containing aggregate, hardening material and water and having a higher fluidity than the first fluidity material has hardened over time, the method being characterized in that the first fluidity material is poured into a formwork, and the second fluidity material is poured onto the first fluidity material at a stage during which the first fluidity material is hardening and does not cause cold joints.

2. 2. The method for manufacturing a plate-shaped concrete member according to claim 1, further comprising the steps of: laying a decorative material on the bottom surface of the formwork; and pouring the first fluid material into the formwork.

3. 3. The method for manufacturing a plate-shaped concrete member according to claim 1, wherein the second fluidity material is richer in the hardening material than the first fluidity material.

4. 2. The method for manufacturing a plate-shaped concrete member according to claim 1, wherein the first fluid material is fresh concrete whose hardening material is cement, and the second fluid material is mortar paste whose hardening material is cement.

5. A plate-shaped concrete member comprising: a first layer portion on the front side in which a first fluid material containing aggregate, a hardening material, and water has hardened over time; and a second layer portion on the back side in which a second fluid material containing aggregate, a hardening material, and water and having a higher fluidity than the first fluid material has hardened over time.

6. 6. The plate-shaped concrete member according to claim 5, further comprising a decorative member on a surface of the first layer.

7. 7. The plate-shaped concrete member according to claim 5 or 6, wherein the second fluidity material is richer in the hardening material than the first fluidity material.

8. 6. The plate-shaped concrete member according to claim 5, wherein the first fluidity material is ready-mixed concrete in which the hardening material is cement, and the second fluidity material is mortar paste in which the hardening material is cement.

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