Construction methods for blocks, surface water-proof structures, and slope water-proof structures

Abstract

To provide a block that can be constructed by using only relatively inexpensive materials and also has high impermeable performance, and a surface impermeable structure with high impermeable performance equipped with the block.SOLUTION: An impermeable layer 1, which is installed as the surface layer of the slope S, comprises block 2 formed by compacting slag material 3, which is a mixture of steelmaking slag and granulated blast furnace slag, so that the compaction density ratio is 90% or more, and slag material 3, which is filled in a gap between adjacent blocks. Here, the block should be compacted so that the compaction density ratio of the slag material is 95% or more. The thickness should be 50 mm - 200 mm and the hydraulic conductivity should be less than 3.0×10-6 m / s.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to blocks that are arranged on the surface of a slope or pavement, and a method for constructing a waterproof structure for the surface and a waterproof structure for a slope that include the blocks. [Background technology]

[0002] As disclosed in Patent Documents 1 and 2, slopes formed by cutting and filling are stabilized by using concrete or other materials to prevent the infiltration of rainwater, which can cause slope collapse.

[0003] For example, Patent Document 1 discloses that a waterproof structure is provided on the surface by spraying concrete onto a slope. Patent Document 2 also discloses a slope stabilization work in which vertical beams are constructed from reinforced concrete and the slope exposed between the vertical beams is covered with a greening spray material.

[0004] Furthermore, Patent Document 3 discloses a vegetation-covering block construction method in which flat concrete blocks are laid on a slope for protection, and the surface of the concrete blocks is covered with vegetation. In this construction method, porous concrete is used for the concrete blocks to make it easier for plants to grow.

[0005] On the other hand, Patent Documents 4 and 5 describe a simple road paving method in which a material made from a mixture of steelmaking slag and granulated blast furnace slag is spread evenly, and after watering, the mixture is compacted using a rolling machine such as a large road roller or a small plate compactor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-197934 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-52533 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-68867 [Patent Document 4] Patent No. 5765125 [Patent Document 5] Japanese Patent Application Publication No. 2017-48625 Summary of the Invention [Problem to be solved by the invention]

[0007] However, binders such as cement and asphalt are expensive, which increases construction costs. Furthermore, materials that require sufficient compaction are preferably manufactured in advance in a location where compaction work can be easily carried out. However, when used in block-like shaped structures, it is difficult to ensure that the joints between the blocks have the same performance as blocks. For this reason, in the case of the slab block construction described in Patent Document 3, even when dense concrete blocks with high water-blocking properties are used, seepage occurs through the joints, so the entire slope cannot be expected to be water-blocking.

[0008] Therefore, the present invention aims to provide a method for constructing a block that can be constructed using only relatively inexpensive materials and has high water-blocking performance, as well as a surface water-blocking structure and a slope water-blocking structure that have high water-blocking performance and are equipped with the block. [Means for solving the problem]

[0009] In order to achieve the above object, the block of the present invention is characterized in that it is made by compacting a slag material, which is a mixture of steelmaking slag and granulated blast furnace slag, so that the compaction density ratio is 90% or more.

[0010] Here, it is preferable to compact the slag material so that the compaction density ratio is 95% or more. For example, the steelmaking slag may have a particle size of 40 mm or less, and the content of the granulated blast furnace slag relative to the total amount of the slag material may be 5% by mass or more and 25% by mass or less. The thickness of the block may be 50 mm to 200 mm. Furthermore, the hydraulic conductivity of the block may be 3.0 x 10 -6It is preferable to set the speed to m / s or less.

[0011] The invention also provides a waterproof surface structure, characterized in that it comprises any of the blocks described above and the slag material or granulated blast furnace slag filled in the gaps between adjacent blocks.

[0012] Furthermore, the invention of a method for constructing a water-blocking structure for a slope is a method for constructing a water-blocking structure for a slope that is provided as the surface layer of the slope, characterized in that it comprises the steps of manufacturing any of the blocks described above, installing a plurality of the blocks on the slope, discharging the slag material or granulated blast furnace slag between the blocks arranged on the slope, and spraying water on the slag material or granulated blast furnace slag. [Effects of the Invention]

[0013] The block of the present invention configured as described above is formed by compacting a slag material, which is a mixture of steelmaking slag and granulated blast furnace slag, so that the compaction density ratio is 90% or more.

[0014] In short, since it only uses steelmaking slag generated in the steelmaking process and granulated blast furnace slag, the material costs can be kept relatively low. Furthermore, by compacting the material to a compaction density ratio of 90% or more, high water-blocking performance can be ensured. In particular, by achieving a compaction density ratio of 95% or more, the rate at which rainwater penetrates slopes and beneath pavement surfaces can be significantly reduced.

[0015] The surface layer formed by laying such blocks can be made into a waterproof structure with high waterproofing performance by filling the gaps between adjacent blocks with slag material or granulated blast furnace slag.

[0016] In addition, in the invention of a method for constructing a water-tight structure on a slope, blocks formed from slag material manufactured at another location are used, and after the blocks are installed on the slope, a process is carried out in which slag material or granulated blast furnace slag is spread between the blocks and water is sprayed.This makes it possible to construct a water-tight structure with high water-tightness even in places where compaction work is difficult, such as slopes. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an explanatory diagram showing the configuration of a water-blocking structure for a slope according to an embodiment of the present invention; [Figure 2] FIG. 1 is an explanatory diagram showing an overview of a ground model used in a water sprinkling experiment conducted to confirm the effectiveness of the water-blocking structure for a slope according to this embodiment. [Figure 3] FIG. 1 is a diagram illustrating the relationship between moisture content, dry density, and hydraulic conductivity. [Figure 4] Figures explaining the results of the water sprinkling experiment along with comparative examples, where (a) is a graph showing the time history of infiltration rate when the rainfall intensity is 20 mm / hr, and (b) is a graph showing the time history of infiltration rate when the rainfall intensity is 90 mm / hr. [Figure 5] These figures explain the results of a water sprinkling experiment with a rainfall intensity of 20 mm / hr. (a) is a graph showing the time history of saturation at a downstream point on the slope, (b) is a graph showing the time history of saturation at a central point on the slope, and (c) is a graph showing the time history of saturation at an upstream point on the slope. [Figure 6] These figures explain the results of a water sprinkling experiment with a rainfall intensity of 90 mm / hr. (a) is a graph showing the time history of saturation at a downstream point on the slope, and (b) is a graph showing the time history of saturation at the center point on the slope. [Figure 7] 1 is a flowchart illustrating a method for constructing a waterproof structure for a slope according to the present embodiment. [Figure 8] FIG. 10 is a perspective view illustrating the process of discharging slag material into a formwork. [Figure 9] FIG. 10 is a perspective view illustrating a state in which blocks are arranged on a slope. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing, in an enlarged scale, a part of the configuration of a water-blocking structure of a slope S as a water-blocking structure of a surface layer described in this embodiment.

[0019] That is, the waterproof structure of the surface layer of this embodiment can be applied to both flat paved surfaces and slopes S, but the following will mainly explain the case where it is applied to slopes S. First, the overall configuration will be explained with reference to Fig. 1. Slopes S include inclined surfaces that occur when cutting to excavate natural ground, and inclined surfaces that occur when piling up soil on the foundation ground to build a levee or developed land.

[0020] Here, we will explain the example of a water-impermeable layer 1 that forms the surface layer of a slope S with a gradient of 1:2.0, that is, a slope S that is inclined at an angle of approximately 26° from the horizontal. On such a slope S, the water-impermeable layer 1 is provided to prevent rainwater from seeping into the interior of the slope S and eroding the surface, which can cause slope collapse.

[0021] The most important performance required of this water impermeable layer 1 is water blocking performance, and the smaller the permeability coefficient, the better. Furthermore, it is preferable that the water impermeable layer 1 be constructed using only relatively inexpensive materials, without using expensive materials such as cement or asphalt.

[0022] Therefore, in this embodiment, the water impermeable layer 1 is formed from a slag material that is a mixture of steelmaking slag and granulated blast furnace slag. Steelmaking slag, granulated blast furnace slag, and other iron and steel slags are industrial by-products generated in the steelmaking process, and are relatively inexpensive to obtain. Effective use of these slags can also contribute to reducing environmental impact.

[0023] Steelmaking slag and granulated blast furnace slag are composite materials whose main components are calcium oxide, calcium silicate, iron (II) oxide, alumina, etc., and have latent hydraulic properties. Steelmaking slag alone has weak hydraulic properties and exhibits strength, but by mixing steelmaking slag with granulated blast furnace slag, the strongly alkaline steelmaking slag stimulates the granulated blast furnace slag, which has even stronger hydraulic properties, producing hydrates and resulting in a strong solidified body.

[0024] To explain in more detail, when granulated blast furnace slag is exposed to the alkaline action of steelmaking slag, silica (Si) and aluminum (Al) dissolve into the water and undergo a pozzolanic reaction with calcium (Ca) dissolved from the steelmaking slag to produce lime-silica-alumina (CSAH: C=CaO, S=SiO2, A=Al2O3, H=H2O) hydrate, which connects and fills the gaps between the particles, causing solidification. In addition, excess Ca ions in the water react with carbonate ions in the air to produce calcium carbonate (CaCO3), which also solidifies.

[0025] To construct a water impermeable layer 1 using such a slag material, which is a mixture of steelmaking slag and granulated blast furnace slag, the slag material is spread evenly on the slope S, water is sprayed on top to promote hydraulic properties, and the slag is compacted by rolling with a roller or the like. However, since it is difficult to perform sufficient compaction by rolling on the slope S, in this embodiment, blocks that have been sufficiently compacted and formed in another location are used, as will be described later. First, the performance required for the water impermeable layer 1 formed from the slag material will be explained.

[0026] As the steelmaking slag, for example, steelmaking slag having a particle size of 40 mm or less that passes through a 40 mm mesh sieve can be used. As the granulated blast furnace slag, glassy granular slag that has been rapidly cooled by, for example, injecting pressurized water into molten blast furnace slag can be used.

[0027] Granulated blast furnace slag is mixed so that its content is, for example, 5% by mass or more and 25% by mass or less relative to the total amount of slag material. In contrast, the content of steelmaking slag is 75% by mass or more and 95% by mass or less relative to the total amount of slag material. In other words, the total amount of slag material is the combination of steelmaking slag and granulated blast furnace slag.

[0028] Sufficient compaction is required to achieve the required water-blocking performance of the water-blocking layer 1. Below, we will explain the relationship between the degree of compaction and permeability, and also explain the water-blocking structure suitable for the water-blocking layer 1 to be installed as the surface layer of the slope S. First, with reference to Figures 2 to 6, we will explain the water-spraying experiment conducted to confirm the water-blocking performance.

[0029] In this water sprinkling experiment, a ground model of a sloping ground simulating the vicinity of the slope (see Figure 2) was created to understand the difference in water-blocking performance depending on the construction conditions (moisture content, dry density) of the slope S (slope surface) using the above-mentioned slag material.

[0030] In conducting this water spray experiment, we conducted permeability tests on slag specimens with different moisture contents and densities (dry densities) to understand how the permeability coefficient changes depending on the moisture content and dry density. First, as shown in Figure 3, we conducted permeability tests on specimens with moisture contents ranging from 7% to 11% and compacted density ratios of 90% to 99%. Here, the compacted density ratio (Dc) is the ratio between the dry density of the sample and the maximum dry density, and is an index that represents the degree of compaction, sometimes referred to as the "degree of compaction."

[0031] As a result of a series of tests, it was found that the coefficient of permeability decreases as the moisture content increases and approaches the optimum moisture content of 11%, and that the coefficient of permeability decreases as the compacted density ratio (dry density) increases. In particular, when the optimum moisture content is close to 11% and the compacted density ratio is as high as 99%, the coefficient of permeability is 1.0 x 10 -8 It was confirmed that the value was extremely small, less than m / s.

[0032] In addition, for specimens with a moisture content greater than the optimum, permeability tests were conducted on specimens of slag material with different moisture contents to understand the change in permeability coefficient due to the magnitude of the moisture content in a range greater than the optimum.The compacted density ratio for these specimens was set to 90%, and three types of specimens with moisture contents of 11%, 12%, and 13% were prepared.

[0033] As a result of conducting a permeability test on these three types of specimens, the specimen with a water content of 11% had a permeability of 1.11×10 -5 (m / s), and 1.76 × 10 for the specimen with a water content of 12%. -5 (m / s), and 2.24 × 10 for the specimen with a water content of 13%. -5 The result of the coefficient of permeability k was (m / s). In short, the coefficient of permeability k was almost the same regardless of the water content, and it was found that the influence of the water content on the coefficient of permeability k was small in the range above the optimum water content.

[0034] Figure 2 shows an overview of the ground model used in a water sprinkling experiment conducted to confirm the effectiveness of the water-blocking structure for slopes according to this embodiment. This ground model has a structure in which a slope protection work using slag material is laid on a 120 mm thick layer of slope ground (made with Tohoku Silica Sand No. 6) that simulates slope S.

[0035] The water impermeable layer 1 was 150 mm thick, and the slope length was approximately 1,700 mm. When constructing the water impermeable layer 1 on an actual slope S, it is preferable to form the layer to a thickness of approximately 50 mm - 200 mm. In addition, a permeable plate was installed at the foot of the slope S (downstream of the surface water), and the area around it was left as an opening that was not part of the slope ground, so that the amount of surface water could be measured. Furthermore, in the slope ground simulating slope S, multiple drainage channels were installed perpendicular to the underside, so that the amount of infiltration could be measured.

[0036] After constructing the ground model, the soil tank was tilted at an angle of 26° to simulate a 1:2.0 slope S (see Figure 1). Soil moisture meters and pore water pressure gauges were installed at 300 mm intervals on the slope ground. The soil moisture meters were labeled PWP01, PWP02, etc., starting from the bottom of the slope (downstream of the surface water), and the pore water pressure gauges were labeled M01, M02, etc., starting from the bottom of the slope.

[0037] The water spraying experiment was conducted under multiple patterns with different rainfall intensities. Specifically, water spraying experiments were conducted with rainfall intensities of 20 mm / hr and 90 mm / hr. In addition, the water shielding layer 1 was simulated in multiple cases (Case 1-Case 3) with different compaction levels, while the slag material mix was the same.

[0038] The slag material was mixed with 80% by mass of steelmaking slag (particle size 25 mm or less) and 20% by mass of granulated blast furnace slag (particle size 2 mm). The initial moisture content was 11.0% in both cases.

[0039] And, in Case 1, the dry density is 2.263 (g / cm 3 ) The degree of compaction is 99% in terms of the compacted density ratio (Dc), which is expressed as a ratio to the maximum dry density. The permeability coefficient k measured in the laboratory permeability test for Case 1 is 9.04 × 10 -9 (m / s).

[0040] In addition, in Case 2, the dry density is 2.057 (g / cm 3 ) The degree of compaction is expressed as a ratio to the maximum dry density, or compacted density ratio (Dc), of 90%. The permeability coefficient k measured in the laboratory permeability test for Case 2 is 1.11×10 -5 (m / s).

[0041] Furthermore, in Case 3, the dry density was 2.171 (g / cm 3) The degree of compaction is 95% in terms of the compacted density ratio (Dc), which is expressed as a ratio to the maximum dry density. The permeability coefficient k measured in the laboratory permeability test for Case 3 is 3.19 × 10 -6 (m / s).

[0042] In the water spraying experiment, water was sprayed onto the inclined ground model at a rainfall intensity of 20 mm / hr or 90 mm / hr, and the amount of surface water discharged from the permeable plate position, the amount of infiltration discharged from the underside of the slope ground, and the detection values of the soil moisture meter and pore water pressure meter were measured.

[0043] Figures 4 to 6 show the experimental results for each rainfall intensity. For comparison, the experimental results for the case where the water shielding layer 1 was not installed (no countermeasure) are also shown. First, Figure 4 shows the time history of the infiltration rate for a rainfall intensity of 20 mm / hr (Figure 4(a)) and a rainfall intensity of 90 mm / hr (Figure 4(b)).

[0044] Here, infiltration rate (%) is a value that indicates the ratio of infiltration rate to the total of surface water volume and infiltration rate, and is calculated using the formula: Infiltration rate = infiltration rate / (surface water volume + infiltration rate). Looking at these results, it was confirmed that at any rainfall intensity, there was almost no infiltration rate in Case 1, and no infiltration into the interior of slope S occurred.

[0045] On the other hand, Case 2 showed almost no water-blocking effect, and the infiltration rate was the same as with no measures taken. In contrast, Case 3, in which the compaction density ratio was 95%, did not achieve complete water-blocking, but it can be said that a considerable amount of rainfall did not infiltrate and instead flowed down as surface water (surface runoff).

[0046] Therefore, we decided to set the rainfall intensity at 20 mm / hr and verify the differences in each case depending on the position on slope S. Here, according to the Japan Meteorological Agency's classification of "rain intensity and precipitation pattern," a rainfall intensity of 20 mm / hr corresponds to "heavy rain" in forecast terms and to "downpour" in people's minds.

[0047] Figure 5 is a graph showing the time history of the degree of saturation (%), where Figure 5(a) shows the degree of saturation at a downstream point on slope S (point PWP01 in Figure 2), Figure 5(b) shows the degree of saturation at a central point on slope S (point PWP03 in Figure 2), and Figure 5(c) shows the degree of saturation at an upstream point on slope S (point PWP06 in Figure 2).

[0048] Looking at these results, it can be seen that at the downstream point (Figure 5(a)), the degree of saturation was low in the case where no measures were taken, and the degree of saturation was relatively high in the cases where slope protection work was carried out with a water barrier layer 1 made of slag material (Case 1-Case 3).

[0049] This is thought to be because, without any countermeasures, rainfall seeps almost evenly into the interior of slope S (inside the embankment), whereas with the construction of the water-impermeable layer 1, more surface water flows down the surface of the water-impermeable layer 1, and some of this seeps in near the downstream point (the foot of the slope). In short, it is thought that the amount of inflow at the foot of the slope will be greater than in the case of no countermeasures.

[0050] On the other hand, at the central point (Figure 5(b)), the saturation levels for the no-measure and Case 2 cases showed similar time histories, while in Cases 1 and 3, there was almost no increase in saturation level, and similar to the permeability results shown in Figure 4, no increase was observed over time.

[0051] At the upstream point (Figure 5(c)), an increase in saturation was confirmed in the order of Case 1, Case 3, Case 2, and no countermeasures. At the downstream and central points, infiltration was confirmed to be the same as or greater than that of no countermeasures, but even in Case 2, a certain degree of water-blocking effect was confirmed at the upstream point.

[0052] Figure 6 shows the results of verifying the difference in saturation rate (%) over time for each position on slope S, assuming a rainfall intensity of 90 mm / hr. Here, according to the Japan Meteorological Agency's classification of "rain intensity and precipitation pattern," a rainfall intensity of 90 mm / hr is described in forecast terms as "torrential rain," and in people's imagination as "a feeling of oppression that makes it difficult to breathe, and a feeling of fear."

[0053] In the graph of Figure 6, which shows the time history of saturation, Figure 6(a) shows the saturation at a downstream point on slope S (point PWP01 in Figure 2), and Figure 6(b) shows the saturation at a central point on slope S (point PWP03 in Figure 2).

[0054] Looking at these results, at the downstream point (Figure 6(a)), the results were similar to those for a rainfall intensity of 20 mm / hr, but at the central point (Figure 6(b)), it was confirmed that the increase in saturation was suppressed even in Case 2.

[0055] When the inflow volume becomes very large, such as in the case of a rainfall intensity of 90 mm / hr, which is classified as "heavy rain," a certain amount is drained as surface water, which is thought to suppress the increase in saturation level inside slope S.

[0056] Since slag is alkaline, the pH of each case was also measured for reference. In all cases, the average pH of the surface water was approximately 7.8-8.5, and the pH of the permeated water was approximately 8.2-11.7. However, as carbonation of the slag progresses from the surface, these pH values gradually decrease over time.

[0057] Next, the blocks of this embodiment that can exhibit such water-blocking performance will be described together with the method for constructing a water-blocking structure for a slope of this embodiment. Figure 7 shows a flowchart explaining each step of the method for constructing a water-blocking structure for a slope of this embodiment.

[0058] Steps S1 to S5 of this flowchart represent the steps of the process for manufacturing the block 2 of this embodiment. That is, this is a manufacturing method for the block 2 in which a slag material, which is a mixture of steelmaking slag and granulated blast furnace slag, is compacted to have a compaction density ratio of 90% or more.

[0059] In this embodiment, the block 2 is manufactured on a flat surface where compaction work can be easily performed. For example, the block 2 can be manufactured on the site of a factory or a sloped construction site, or on a flat work yard nearby. First, in step S1, as shown in FIG. 8, formwork 4 is assembled on a flat surface.

[0060] In order to manufacture a plurality of blocks 2 at once, the formwork 4 has an outer frame 41 having a height at least equal to the thickness of the block 2, and an inner space capable of accommodating the number of blocks 2 to be manufactured at once. Here, the plurality of blocks 2 can also be manufactured by dividing an integrally molded plate body into smaller pieces, but Figure 8 shows the case where a partition frame 42 is used.

[0061] The compartment frame 42 is an inner formwork that divides the space inside the outer frame 41, which is formed in a roughly rectangular shape when viewed from above, into a grid pattern, and one block 2 is formed in each compartment divided by the compartment frame 42. For example, one compartment is set to be a square of 250 mm x 250 mm when viewed from above. Note that the formwork 4 can be easily assembled into the desired shape, so it can be set so that the block 2 can be formed into the desired shape, taking into consideration the shape of the slope S, the means of transportation, efficiency, etc.

[0062] On the other hand, the height of the compartment frame 42 is set lower than the height of the outer frame 41. Then, the thickness of the block 2 after compaction will be approximately the same as the height of the compartment frame 42. The height of the compartment frame 42 can be set to approximately 50 mm to 200 mm. For example, the height of the compartment frame 42 is set to 120 mm.

[0063] In step S2, slag material 3 is poured into the compartments within the formwork 4. For example, a slag material 3 is used in which the particle size of the steelmaking slag is 40 mm or less and the content of granulated blast furnace slag relative to the total amount is 5% by mass or more and 25% by mass or less. The slag material 3 is filled, for example, up to the height of the outer frame 41 of the formwork 4. At this stage, the upper end surface of the compartment frame 42 is buried and hidden by the slag material 3.

[0064] Next, in step S3, the amount of water required to harden the slag material 3 is sprayed. That is, by spraying water, the moisture content of the slag material 3 is adjusted to a desired range. Note that if the moisture content of the slag material 3 has been adjusted in advance, the water spraying step is omitted.

[0065] In step S4, a rolling machine such as a vibro compactor or a plate compactor is used to compact the inside of the formwork 4. When the rolling work is performed, the spread slag material 3 is compacted and its thickness decreases. For example, the spread slag material 3 having a thickness about the height of the outer frame 41 is compacted until it reaches the height of the compartment frame 42.

[0066] This compaction work is carried out inside the formwork 4 installed on a flat surface, so it can be carried out efficiently until the concrete is sufficiently compacted. In addition, by controlling the height of the outer frame 41 and the compartment frame 42, it is possible to efficiently manufacture high-quality blocks 2 with a stable quality.

[0067] After compaction, the blocks 2 are cured for a predetermined time, so that they develop a predetermined strength. After curing for a predetermined time, the formwork 4 is removed and the blocks 2 are taken out (step S5). This results in multiple blocks 2 being formed. If necessary, the surfaces of the removed blocks 2 can be scraped to adjust their shape.

[0068] If the blocks 2 are manufactured in a factory, they are loaded onto trucks and transported to the site. If they are manufactured in a work yard near the slope S, they are transported to the slope S by workers or with a small backhoe or crane and set up (step S6). The rectangular parallelepiped blocks 2 measuring 250 mm x 250 mm x 120 mm weigh about 20 kg, so they can be transported manually. Furthermore, if the thickness is halved to 60 mm, the weight is also halved to 10 kg, making them easier to handle.

[0069] Figure 9 shows a state in which multiple blocks 2 have been arranged on a slope S after the installation process. The blocks 2 are arranged so that they are aligned in the inclination direction and width direction of the slope S, for example, and gaps that become joint gaps 21 are generated between adjacent blocks 2, 2, although the width of the joint gaps 21 may vary to a certain extent. The width of the joint gaps 21 may be set in advance within a range of several millimeters to several centimeters, or may be a naturally occurring gap.

[0070] In step S7, a process is carried out in which slag material 3 is spread toward the joint gaps 21. The slag material 3 used in this process can be a material that has a higher fine particle content than the material used to manufacture the block 2 and is therefore easier to fill in narrow gaps. It is also possible to fill the gaps with only granulated blast furnace slag, which has a smaller particle size than steelmaking slag.

[0071] The slag material 3 can be spread along the joint gap 21, or it can be spread over a wide area around the joint gap 21 and then dropped into the joint gap 21 with a rake, a tongs, a broom, or the like. If necessary, the slag material 3 filled in the joint gap 21 can be compacted with a rod-shaped material or the like.

[0072] Then, in step S8, water is sprayed over a wide area of the entire slope S, including the joint gaps 21 and their surroundings, to harden the slag material 3 filled in the joint gaps 21. If depressions or the like form in the joint gaps 21 as a result of the water spraying process, the spreading of slag material 3 and the spraying of water are repeated until the slag material 3 is filled into the joint gaps 21 to a height approximately the same as the top of the blocks 2. After this, the slag material 3 in the joint gaps 21 hardens, completing a water-impermeable layer 1 with high water-proofing performance.

[0073] Next, the functions of the block 2 of this embodiment, the waterproof structure of the surface layer including the block 2, and the method for constructing the waterproof structure of the slope will be described. The blocks 2 of this embodiment configured as described above are formed by compacting a slag material 3, which is a mixture of steelmaking slag and granulated blast furnace slag, to a compaction density ratio of 90% or more. The water-impermeable layer 1, which serves as the water-impermeable structure of the slope S of this embodiment, is constructed by laying a plurality of blocks 2.

[0074] In short, since it only uses steelmaking slag generated in the steelmaking process and granulated blast furnace slag, the material costs can be kept relatively low. Also, by compacting the material so that the compaction density ratio is 90% or more, it is possible to ensure high water-blocking performance that does not increase the degree of saturation, at least near the shoulder of the slope S (upstream of the surface water).

[0075] Furthermore, when the rainfall intensity is high, it is possible to prevent the degree of saturation from increasing not only near the shoulder of the slope S but also near the center. Furthermore, by setting the compaction density ratio to 95% or more, it is possible to significantly reduce the rate at which rainwater infiltrates the slope S and below the pavement surface.

[0076] Such a water-impermeable layer 1 can be constructed by compacting slag material 3, in which the grain size of the steelmaking slag is 40 mm or less and the content of granulated blast furnace slag is 5% to 25% by mass of the total amount, by rolling on a flat surface to produce blocks 2, and then placing these blocks 2. The slag material 3 is filled and solidified in the joint gaps 21 between the blocks 2, 2, so that the same type of slag material 3 is solidified and integrated into the blocks 2 and the joints, thereby improving the water-impermeable performance of the slope S as a whole.

[0077] Furthermore, by setting the thickness of the water-impermeable layer 1 formed by the slag material 3 to about 50 mm to 200 mm, it is possible to obtain the desired water-impermeable performance while suppressing material costs. -6 By using blocks 2 that have been compacted to a speed of less than m / s, it is possible to prevent rainwater from seeping into the interior of slope S, such as embankments or natural ground, and causing collapse.

[0078] In short, by using blocks 2 formed from slag material 3 manufactured at another location, installing the blocks 2 on the slope S, and then carrying out a process of spreading the slag material 3 between the blocks 2 and sprinkling water, it is possible to construct a waterproof structure with high water-tightness even in places such as the slope S where compaction is difficult.

[0079] The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0080] For example, in the above embodiment, a slope S with a gradient of 1:2.0 was used as an example, but this is not limited to this, and the present invention can also be applied to flat pavements and embankments or cuts with slopes of any gradient. [Explanation of symbols]

[0081] 1: Water impermeable layer (surface layer) 2: Block 21: Joint gap (gap) 3: Slag material 4: Formwork S: Slope

Claims

1. A slag material obtained by mixing steelmaking slag and granulated blast furnace slag is compacted and molded so that the compaction density ratio is 90% or more, A block characterized in that the steelmaking slag has a particle size of 40 mm or less, and the content of the granulated blast furnace slag relative to the total amount of the slag material is 5 mass% or more and 25 mass% or less.

2. 2. The block according to claim 1, characterized in that the slag material is compacted so that the compacted density ratio is 95% or more.

3. 3. Block according to claim 1 or 2, characterized in that it has a thickness of 50 mm to 200 mm.

4. Permeability coefficient is 3.0 x 10 -6 4. The block according to claim 1, wherein the speed is less than or equal to m / s.

5. A block according to any one of claims 1 to 4; A waterproof structure for a surface layer, characterized in that the slag material or granulated blast furnace slag is filled in gaps between adjacent blocks.

6. A method for constructing a water-blocking structure for a slope to be provided as a surface layer of the slope, comprising: A process for producing a block according to any one of claims 1 to 4; placing a plurality of the blocks on the slope; a step of scattering the slag material or granulated blast furnace slag between the blocks arranged on the slope; A method for constructing a waterproof structure for a slope, comprising a step of spraying water onto the slag material or granulated blast furnace slag.

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