Method for manufacturing clayey soil cement, method for manufacturing clayey soil cement molded product

Abstract

To provide a method for producing soil cement that enables the rapid and efficient supply of soil cement. [Solution] A method for producing clayey soil cement 50, characterized by performing the following steps in the order described above: putting clayey soil 20 into a mixing container 10; adding a predetermined amount of water 30 to the mixing container 10 in relation to the amount of clayey soil 20 to be put into the mixing container 10 and mixing the clayey soil 20 and water 30; and adding a predetermined amount of cement 40 to the mixing container 10 in relation to the amount of clayey soil 20 to be put into the mixing container 10 and mixing the clayey soil 20, water 30 and cement 40.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing cohesive soil cement and a method for manufacturing a cohesive soil cement molded body. More specifically, the present invention relates to a method for manufacturing cohesive soil cement that can efficiently manufacture cohesive soil cement and a cohesive soil cement molded body in a short time, and a method for manufacturing a cohesive soil cement molded body.

Background Art

[0002] Soil cement obtained by mixing earth and sand with cement is known. Various methods have been proposed for such a method of manufacturing soil cement. In recent years, a manufacturing method as disclosed in Patent Document 1 (Japanese Patent No. 7042016) has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the method for manufacturing soil cement disclosed in Patent Document 1, it is preferably used in that even in the case of cohesive soil, more earth and sand can be utilized during the manufacture of soil cement. However, there is a problem that a method for manufacturing soil cement that is more efficient and can be carried out in a shorter time is strongly desired.

Means for Solving the Problems

[0005] Therefore, an object of the present invention is to propose a method for manufacturing cohesive soil cement that can provide cohesive soil cement efficiently in a short time, and a method for manufacturing a cohesive soil cement molded body.

[0006] In order to solve the above problems, the inventors conducted diligent research and came up with the following configuration. That is, the present invention is a method for producing clayey soil cement, characterized by performing the following steps in order: putting clayey soil into a mixing container; putting a predetermined amount of water into the mixing container relative to the amount of clayey soil into the mixing container and mixing the clayey soil and the water; and putting a predetermined amount of cement into the mixing container relative to the amount of clayey soil into the mixing container and mixing the clayey soil, the water and the cement.

[0007] This makes it possible to provide soil cement quickly and efficiently.

[0008] Furthermore, it is preferable that the water contains a predetermined amount of dispersant relative to the amount of clay added to the mixing container.

[0009] This makes it possible to provide soil cement more quickly and efficiently.

[0010] Furthermore, there is an invention for a method of manufacturing a clayey soil cement molded body, characterized by assembling a shape-retaining body in which a bag made of a water-permeable material is placed with the opening of the bag facing upwards in the internal space of a cylindrical body in which a plurality of grids are formed on the outer surface by intersecting a plurality of vertical and a plurality of horizontal wires, and filling the inside of the bag with clayey soil cement manufactured by the above method.

[0011] This makes it possible to provide soil-cement molded products quickly and efficiently.

[0012] Furthermore, it is preferable that the cylindrical body has two semi-circular grids with engaging portions formed at both ends in the arc direction, and a connecting body that connects each of the semi-circular grids when assembled to the cylindrical body, and that the cylindrical body is formed by inserting the connecting body in the height direction into the gap formed by the engaging portions with the concave sides of the curved surfaces of each of the semi-circular grids facing each other.

[0013] Furthermore, it is preferable to connect the two adjacent cylindrical bodies by shifting one cylindrical body in the height direction of the other cylindrical body, extending a portion of the circumferential range of the transverse wire in one cylindrical body radially inward from the outer surface of the other cylindrical body, and then inserting a connecting body in the height direction into the radial gap surrounded by the transverse wire in one cylindrical body and the transverse wire in the other cylindrical body.

[0014] These methods enable the efficient production of multiple soil-cement molded bodies. [Effects of the Invention]

[0015] By adopting the configuration of the present invention, it becomes possible to manufacture cohesive soil cement and cohesive soil cement molded articles quickly and efficiently, thereby reducing the manufacturing costs of cohesive soil cement and cohesive soil cement molded articles. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic flowchart showing the manufacturing process of the cohesive soil cement molded body in this embodiment. [Figure 2] The cohesive soil used in this embodiment is the result of tests based on the "Soil Particle Size Test" specified in JIS A1204 and the "Soil Liquid Limit and Plastic Limit Test" specified in JIS A1205. [Figure 3] Diagram (A) shows the inner wall of the mixing container, Diagram (B) shows the state after clayey soil has been added to the mixing container, Diagram (C) shows the state after more water containing a dispersant has been added to the mixing container, and Diagram (A) shows the state after more cement has been added to the mixing container. [Figure 4] This is a perspective view of a cylindrical body formed by a semicircular grid and connecting members. [Figure 5] These are a plan view (A) and a front view (B) of a semicircular grid. [Figure 6] Figure 4 is a perspective view of a shape-retaining body, which consists of a cylindrical body fitted with a bag made of a water-permeable material. [Figure 7] It is a perspective view showing a state in which the bag body of the shape retainer shown in FIG. 6 is filled with viscous soil cement. [Figure 8] It is an explanatory view showing a state in which a soil retaining structure is constructed by a plurality of viscous soil cement molded bodies. [Figure 9] It is a plan view showing an assembled state of the cylindrical body when assembling a plurality of shape retainers. [Figure 10] It is an enlarged view of the X part in FIG. 9. [Figure 11] It is a comparison result of the kneading time and strength test between the viscous soil cement manufactured by the present invention and the viscous soil cement manufactured by the prior art.

Embodiment for Carrying Out the Invention

[0017] Hereinafter, the present invention will be specifically described based on the drawings. FIG. 1 is a schematic flow chart showing the manufacturing process of the viscous soil cement molded body 100 in the present embodiment. In the present embodiment, the viscous soil 20 having a particle size distribution as shown in FIG. 2 is used. The viscous soil 20 in the present embodiment is the one collected in Naganuma Town, Yubari District, Hokkaido. Further, in the present embodiment, a form in which an operator manufactures a predetermined volume of viscous soil cement 50 by batch processing using a mixing container 10 as shown in FIG. 3 and an excavator (not shown) at the place where the viscous soil 20 is collected will be described.

[0018] The mixing container 10 in the present embodiment is formed in a rectangular parallelepiped shape with an open upper surface as shown in FIG. 3(A). On the inner peripheral surface of the mixing container 10, a viscous soil input line 12 and a water input line 14 indicating the height positions of the input soil amount and the input water amount for manufacturing the viscous soil cement 50 with a preset formulation are arranged. The input of the viscous soil 20 into the mixing container 10 is performed by an excavating machine such as an excavator represented by a backhoe. The operator inputs the viscous soil 20 into the internal space of the mixing container 10, compresses the viscous soil 20 with a bucket or the like, and aligns the upper surface height position of the viscous soil 20 with the height position of the viscous soil input line 12 of the mixing container 10 as shown in FIG. 3(B), and thus the input process (S-1) of the viscous soil 20 into the mixing container 10 is completed.

[0019] Next, as shown in Figure 3(C), the worker pours water 30 into the mixing container 10 until the water level reaches the height of the water input line 14 (S-2). In this embodiment, the water 30 used is dispersant-containing water containing a predetermined amount of dispersant based on the amount (volume) of clay 20 poured into the mixing container 10. Next, the worker inserts the bucket of the backhoe into the mixing container 10 and mixes the clay 20 and water 30 that have been poured into the mixing container 10 (S-3). When mixing (kneading) the clay 20 and water 30, a so-called skeleton bucket formed in a grid shape is preferably used. The clay 20 and water 30 are mixed in the internal space of the mixing container 10 to form a paste 35, but if lumps of clay 20 (not shown) remain in the internal space of the mixing container 10, the worker may add a step of removing the lumps of clay 20 from the mixing container 10 (S-4).

[0020] Next, the worker adds a predetermined amount of cement 40 to the mixing container 10 based on the amount (volume) of clayey soil 20 added to the mixing container 10 (S-5). For adding cement 40 to the mixing container 10, it is preferable to use a so-called flexible container bag 42, as shown in Figure 3(D). By making a hole in the bottom of the flexible container bag 42, which has been lifted above the mixing container 10 by a backhoe, cement 40 can be added to the mixing container 10. In this embodiment, blast furnace cement type B is used for cement 40, but the type of cement 40 is not particularly limited.

[0021] Next, the worker inserts the backhoe bucket into the mixing container 10 and mixes (kneads) the paste 35 and cement 40 that have been put into the mixing container 10 (S-6). After mixing (kneading) the paste 35 and cement 40 for a time calculated in advance by experiment to produce cohesive soil cement 50, the worker conducts a slump test on the cohesive soil cement 50 to confirm whether the slump value of the cohesive soil cement 50 is appropriate (S-7). If the slump value of the cohesive soil cement 50 is not appropriate (No in S-7), the worker continues mixing (kneading) the cohesive soil cement 50 in the mixing container 10 for a predetermined time and then conducts the slump test again. If the slump value of the cohesive soil cement 50 is appropriate (Yes in S-7), the worker assembles the shape-retaining body 60 for filling (placing) the cohesive soil cement 50 (S-8).

[0022] As shown in Figures 4 to 6, the shape-retaining body 60 in this embodiment has a cylindrical body 62 and a bag-shaped body 68 made of a water-permeable material. As shown in Figure 4, the cylindrical body 62 in this embodiment is formed by connecting two semi-circular grid bodies 63, each having a plurality of grids 63A formed on its outer surface, with a connecting body 64, with the concave sides of the curved surfaces facing each other. As shown in Figure 5, the semi-circular grid body 63 is formed of a plurality of rod-shaped vertical wires 63B and a plurality of semi-circular horizontal wires 63C. J-shaped engaging portions 63D are formed at both ends of each horizontal wire 63C in the arc direction. The semi-circular grid body 63 is formed by intersecting the horizontal wires 63C perpendicularly at a required interval in the longitudinal direction of the plurality of vertical wires 63B which are arranged parallel to each other at required intervals, and integrating all or part of the intersection portion by welding or the like.

[0023] The worker arranges the semi-circular grid 63 formed in this way, with the concave sides of their curved surfaces facing each other, and offsets the height of the horizontal wires 63C by the diameter of the horizontal wires 63C. In this state, the worker simply inserts the connecting body 64 from above into the gap 65 surrounded by the adjacent engaging parts 63D in the height direction (see enlarged view of Figure 4), and the worker can easily assemble the cylindrical body 62 without needing any special tools. The connecting body 64 is formed by bending the upper end of a rod-shaped member into a J shape, and the J-shaped bent portion engages with the engaging part 63D to prevent it from coming loose. By assembling the cylindrical body 62 at the construction site using the semi-circular grid 63 and the connecting body 64 in this way, the volume during transportation can be greatly reduced, and the transportation cost of the cylindrical body 62 can be reduced.

[0024] After the cylindrical body 62 is assembled, the worker places a bag 68 made of a permeable material into the internal space of the cylindrical body 62 with the opening of the bag 68 facing upwards, as shown in Figure 6 (S-9). The permeability coefficient of the permeable material forming the bag 68 is 1.0 × 10⁻⁶. -2 It is preferable that the water permeability is approximately cm / s. By using a bag body 68 with such water permeability, after filling (placing) the cohesive soil cement 50 into the internal space of the bag body 68, excess water from the cohesive soil cement 50 can be discharged to the outside of the bag body 68, thereby improving the compressive strength of the cohesive soil cement molded body 100. It is preferable for the worker to fold the required height range of the opening of the bag body 68 from the internal space side of the cylindrical body 62 outwards, and tie the lifting string 68A attached to the opening of the bag body 68 etc. to the vertical wire 63B or horizontal wire 63C.

[0025] Once the shape-retaining body 60 is prepared as described above, the worker fills (places) the internal space of the bag body 68 of the shape-retaining body 60 with cohesive soil cement 50 using a backhoe bucket or the like (a regular excavation bucket is preferred) as shown in Figure 7 (S-9). When filling (placing) the bag body 68 with cohesive soil cement 50, it is preferable to use a vibrator as needed. When the cohesive soil cement 50 is filled (placed) into the bag body 68, the bag body 68 expands outward, but because there is a cylindrical body 62 on the outside of the bag body 68, the cohesive soil cement 50 filled (placed) into the bag body 68 can maintain a nearly cylindrical shape. After this, the worker cures the cohesive soil cement 50 filled (placed) into the bag body 68 using a known method (S-10), and a cohesive soil cement molded body 100 that has hardened in a nearly cylindrical shape can be obtained.

[0026] The cohesive soil cement molded body 100 formed in this manner can be lifted to a predetermined location by a lifting device such as a backhoe equipped with a predetermined attachment using a lifting string 68A untangled from a vertical wire 63B or horizontal wire 63C after the cohesive soil cement 50 has hardened. Figure 8 is a perspective view showing a state in which a retaining wall 200 has been constructed by laying multiple cohesive soil cement molded bodies 100. The cohesive soil cement molded body 100 is laid on the surface of the original ground 300 on top of an anti-erosion sheet 400, which is represented by a polyester long-fiber nonwoven fabric, and on top of the anti-erosion sheet 400, a drainage material 500, which is represented by a public drain manufactured by Asahi Kasei Advance Corporation ("Public" is a registered trademark of Asahi Kasei Advance Corporation), and arranged in a predetermined order on top of at least one of these.

[0027] As shown in Figure 8, when stacking the cohesive soil cement molded bodies 100 in the height direction, it is necessary to embed the bottom side of the cohesive soil cement molded body 100 into the original ground 300 to a depth of 500 mm or more in order to stabilize the cohesive soil cement molded body 100 laid at the bottom. Furthermore, it is preferable to place the lower end of the drainage material 500 on the upper surface of the cohesive soil cement molded body 100 located at the bottom. This prevents the occurrence of problems due to drainage at the bottom portion (embedded portion) of the cohesive soil cement molded body 100 at the bottom position.

[0028] When constructing a structure such as a retaining wall 200 using multiple cohesive soil cement molded bodies 100, it is preferable to assemble the shape-retaining bodies 60 in a predetermined arrangement at the construction site of the structure in advance. Figure 9 shows an example of a plan view of the assembled state of the cylindrical bodies 62 when assembling multiple shape-retaining bodies 60. Figure 10 is an enlarged view of the X portion in Figure 9. When arranging multiple cylindrical bodies 62 in the radial direction of the cylindrical bodies 62, as shown in Figure 9, the worker should shift one cylindrical body 62 in the height direction of the other cylindrical body 62 by the diameter of the horizontal wire 63C. When three or more cylindrical bodies 62 are arranged, it is preferable to connect the second cylindrical body 62 to the first cylindrical body 62 by the diameter of the horizontal wire 63C, and the third cylindrical body 62 to the second cylindrical body 62 by the diameter of the horizontal wire 63C, and so on, with the cylindrical bodies 62 being arranged in the same manner, offset from each other in the height direction.

[0029] Next, the worker inserts a portion of the transverse wire 63C of one cylindrical body 62 into the circumferential direction to a position radially inward from the outer surface of the other cylindrical body 62. In this way, the area enclosed by the transverse wire 63C of one cylindrical body 62 and the transverse wire 63C of the other cylindrical body 62 can be used as a radial gap 67. Subsequently, the worker inserts the connecting body 64 into the radial gap 67 from top to bottom (in the height direction), thereby connecting the two cylindrical bodies 62. Here, the connecting body 64 is inserted into a gap 65 enclosed by the engagement portions 63D of the two semicircular grid bodies 63 facing each other (more specifically, the tips of the engagement portions 63D of the two semicircular grid bodies 63), but the present invention is not limited to this form. The connecting body 64 may be inserted into any part of the radial gap 67. Furthermore, the radial gap 67 is not limited to the position of the engaging portion 63D, but can be formed over any range in the circumferential direction of the transverse wire 63C.

[0030] Next, referring to Figure 11, we will compare the cohesive soil cement 50 produced by the manufacturing method of the present invention with the cohesive soil cement 50 produced by the manufacturing method of the conventional technology, which is a comparative example. The comparative example is cohesive soil cement 50 obtained by adding cement 40 to cohesive soil 20 and mixing (kneading), and then adding water 30 and kneading. Here, the results are shown for the production of 6 liters of cohesive soil cement 50.

[0031] On the other hand, the clayey soil cement 50 in the first embodiment was manufactured by adding water 30 to clayey soil 20 and mixing (kneading), and then adding cement 40 and mixing (kneading). The clayey soil cement 50 in the second embodiment was manufactured by adding dispersant-containing water to clayey soil 20 and mixing (kneading), and then adding cement 40 and mixing (kneading). In the second embodiment, the dispersant-containing water was prepared by mixing Geospar F1 (Geospar is a registered trademark of Frolic Co., Ltd.), manufactured by Frolic Co., Ltd., as a dispersant in water 30 at a cement mass ratio of 1%. Here, the cement ratio is determined by a predetermined amount relative to the amount of clayey soil 20 added to the mixing container 10. More specifically, a predetermined mass of dispersant is used relative to the volume of clayey soil 20 added to the mixing container 10.

[0032] The mixing time required to mix the clayey soil 20, water 30, and cement 40 placed in the mixing container 10 until a predetermined slump value (here, 15 cm ± 1.5 cm) was achieved was 8 minutes and 12 seconds (slump value 15.0 cm) for the comparative example, while the mixing time for the clayey soil cement 50 in the first example was 5 minutes and 12 seconds (slump value 16.5 cm), and the mixing time for the clayey soil cement 50 in the second example was 4 minutes and 54 seconds (slump value 15.5 cm). Thus, the mixing time for the clayey soil cement 50 in the first example was 3 minutes shorter than that of the comparative example, and the mixing time for the second example was reduced by about 20 seconds further than that of the first example, demonstrating a significant reduction in mixing time even with 6 liters of clayey soil cement 50. Furthermore, in all three examples (comparative example, first example, and second example), the slump value of the clayey soil cement 50 was within the acceptable range.

[0033] Next, we will compare the strength of the cohesive soil cement molded body 100 in the comparative example and in the first and second examples. The 1-day strength of each cohesive soil cement molded body 100 is 0.27 N / mm², in the order of the comparative example, the first example, and the second example. 2 , 0.27 N / mm 2 , 0.26 N / mm 2Furthermore, the 7-day strength of each of the cohesive soil cement molded bodies 100 was 0.84 N / mm², in the same order. 2 , 0.84 N / mm 2 , 0.96 N / mm 2 Thus, the cohesive soil cement molded articles 100 of the first and second embodiments of the present invention can be manufactured in a shorter time than the comparative example, while having strength equal to or greater than that of the cohesive soil cement molded article 100 in the comparative example. Thus, the present invention is advantageous in that it can significantly reduce the manufacturing cost of the cohesive soil cement molded article 100.

[0034] Although the cohesive soil cement 50 and the cohesive soil cement molded body 100 of the present invention have been described in detail above based on embodiments, the present invention is not limited to the above embodiments. For example, in the above embodiments, a mixing container 10 formed in the shape of a rectangular parallelepiped is exemplified, but the shape of the mixing container 10 is not particularly limited. Furthermore, the cohesive soil 20 used as material is not limited to the particle size distribution, liquid limit and plastic limit shown in Figure 2. The cohesive soil 20 in the present invention is sufficient if it contains 50% or more soil particles with a particle size of 75 μm.

[0035] Furthermore, the presence or absence of a dispersant in the water 30 used in this invention is not a concern, as evidenced by the use of dispersant-free water (first example) and dispersant-containing water (second example). In short, when producing clayey soil cement 50 by mixing (kneading) clayey soil 20, water 30, and cement 40, it is sufficient to have a step in which the clayey soil 20 is mixed (kneaded) with water 30 and then mixed (kneaded) with cement 40.

[0036] Furthermore, in the above embodiments, the assembly of the shape-retaining body 60 for filling (placing) the cohesive soil cement 50 is performed when the slump value of the cohesive soil cement 50 is at an appropriate level. However, the present invention is not limited to this step. The step of assembling the shape-retaining body 60 may be performed at any time as long as it is done before the slump value of the cohesive soil cement 50 reaches an appropriate level.

[0037] Furthermore, it is also possible to adopt a configuration that appropriately combines the modified examples described in the above embodiments. [Explanation of symbols]

[0038] 10: Mixing container, 12: Clay soil input line, 14: Water input line, 20: Clay soil, 30: Water, 40: Cement, 42: Flexible container bag 50: Clay soil cement, 60: Shape-retaining body, 62: Cylindrical body, 63: Semicircular lattice, 63A: Lattice, 63B: Vertical wires, 63C: Horizontal wires, 63D: Engaging part, 64: Connecting body, 65: Gap, 67: Radial gap, 68: Bag body, 68A: Lifting line 100: Clay soil cement molded body 200: Retaining wall 300: Original ground conditions 400: Anti-suction sheet 500: Drainage material

Claims

1. The process involves adding clayey soil to a mixing container, A step of mixing the clay and water by adding a predetermined amount of water to the mixing container in relation to the amount of clay added to the mixing container, A step of adding a predetermined amount of cement to the mixing container in relation to the amount of clayey soil added to the mixing container, and mixing the clayey soil, water, and cement, A method for producing cohesive soil cement, characterized by performing the steps in the order described.

2. The method for producing clayey soil cement according to claim 1, characterized in that the water contains a predetermined amount of dispersant relative to the amount of clayey soil added to the mixing container.

3. A method for manufacturing a clayey soil cement molded body, characterized by assembling a shape-retaining body in which a bag made of a water-permeable material is placed with the opening of the bag facing upwards in the internal space of a cylindrical body in which a plurality of grids are formed on the outer surface by intersecting a plurality of vertical wires and a plurality of horizontal wires, and filling the inside of the bag with clayey soil cement manufactured according to claim 1 or 2.

4. The cylindrical body has two semi-circular grids with engaging portions formed at both ends in the arc direction, and a connecting body that connects each of the semi-circular grids to the cylindrical body when assembled. The method for manufacturing a cohesive soil cement molded body according to claim 3, characterized in that the cylindrical body is formed by inserting the connecting body in the height direction into the gap formed by the engaging portions with the recessed sides of the curved surfaces of each of the semicircular grid bodies facing each other.

5. A method for manufacturing a cohesive soil cement molded body according to claim 3, characterized in that, in adjacent cylindrical bodies, one cylindrical body is offset in the height direction from the other cylindrical body, a portion of the circumferential range of the transverse wire in one cylindrical body is moved radially inward from the outer surface of the other cylindrical body, and then a connecting body is inserted in the height direction into the radial gap surrounded by the transverse wire in one cylindrical body and the transverse wire in the other cylindrical body to connect the cylindrical bodies.

6. A method for manufacturing a cohesive soil cement molded body according to claim 4, characterized in that, in adjacent cylindrical bodies, one cylindrical body is offset in the height direction from the other cylindrical body, a portion of the circumferential range of the transverse wire in one cylindrical body is moved radially inward from the outer surface of the other cylindrical body, and the connecting body is inserted in the height direction into the radial gap surrounded by the transverse wire in one cylindrical body and the transverse wire in the other cylindrical body to connect the cylindrical bodies.

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