Static expansive demolition agent and static expansive method

Abstract

To provide a highly safe static expansive demolition agent to suppress the occurrence of gunshot phenomena.SOLUTION: The static expansion demolition agent comprises a physical expansion material that expands due to physical changes, and the static expansion method comprises filling boreholes of a crushed material with the static expansion demolition agent and then adding water to cause the same to expand.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a static crushing material and a static crushing method that are mainly used in the civil engineering and construction industries. [Background technology]

[0002] Conventionally, a so-called static crushing method is known for crushing brittle objects such as rocks or concrete without applying explosions or mechanical shocks. In the static crushing method, holes are made in the rocks or concrete in advance, and the holes are filled with an expansive slurry, which is then used to crush the rocks or concrete. For example, because quicklime has a large expansive force when hydrated, attempts have been made to use it as a crushing material.

[0003] However, quicklime alone has a very fast hydration rate, and when mixed with water, it immediately hydrates and expands, rapidly reducing its fluidity and making it difficult to inject into the holes. Even if it could be injected, it would blow out of the top of the hole due to a sudden exothermic reaction, a phenomenon known as gunfire, and sufficient crushing effects could not be achieved. It is not clear how the gunfire phenomenon occurs, but since the heat of hydration generated by the sudden exothermic reaction reaches about 120°C, it is assumed that a steam explosion is occurring.

[0004] As a static crushing material using quicklime, a method has been proposed in which a water-reducing agent is added to a mineral powder in which quicklime crystals are encapsulated in alite crystals, or a hydraulic substance and admixture are added to hard-burned quicklime powder, which is then mixed with water to form a paste, which is then injected into holes in rocks or concrete (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 55-142894 [Patent Document 2] Japanese Patent Application Publication No. 56-67059 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the methods described in Patent Document 1 and Patent Document 2 are material designs that appropriately control the hydration reaction of quicklime, there are limitations to the scope of application. In other words, the maximum drilled hole diameter is limited to less than 70 mm. If the drilled hole diameter exceeds 70 mm, the amount of static crushed material to be filled increases, so the amount of heat generated by hydration increases, increasing the risk of the gunshot phenomenon. Therefore, it was necessary to make the drilled hole diameter smaller than a certain size, narrow the drilling interval, and increase the number of drilled holes.

[0007] In addition, quicklime is produced by heating calcium carbonate (CaCO3) made from crushed limestone at high temperatures, which simultaneously produces carbon dioxide. Therefore, from the perspective of carbon neutrality, static crushing materials with a smaller environmental impact will be required in the future.

[0008] In view of the above, an object of the present invention is to provide a static crushing material that suppresses the occurrence of gunshots and is highly safe. [Means for solving the problem]

[0009] The present inventors have conducted intensive research to achieve the above object, and have found that the above problems can be solved by the present invention described below. The present invention is based on the above findings and has the following gist.

[0010] [1] Static fracturing material containing a physically change expanding material that expands due to a physical change. [2] The static crushing material described in [1], in which the length of at least a portion of the physical change expansion material expands to 1.5 times or more 30 minutes after water is added. [3] The static crushing material according to [1] or [2], wherein the physical change expansion material is rod-shaped. [4] The static crushing material according to [3], wherein the diameter of the physical change expansion material is 30 mm to 100 mm. [5] The static crushing material according to any one of [1] to [3], wherein the physically changeable expansive material is compressed wood. [6] A static crushing method comprising filling a static crushing material according to any one of [1] to [5] into a drilled hole in an object to be crushed and adding water to expand the material. [7] A static crushing method according to [6], wherein the material to be crushed is a hardened cement body, boulders or bedrock. Effect of the Invention

[0011] According to the present invention, it is possible to provide a static crushing material which is highly safe and suppresses the occurrence of gunshots. [Brief description of the drawings]

[0012] [Figure 1] Photographs showing the compressed wood of Experimental Example 1 before and after expansion, with the left side showing the wood before expansion and the right side showing the wood after expansion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the static crushing material and the static crushing method according to one embodiment of the present invention will be described in detail.

[0014] [Static crushing material] The static crushing material according to this embodiment includes a physically changeable expanding material that expands due to a physical change. Physical change expansive materials do not undergo a chemical change of their own material and expand as a result of this, but rather expand by changing the volume when water is added, without changing the material itself. Therefore, when quicklime undergoes a chemical change with water, there is no sudden exothermic reaction that causes the material to erupt. In addition, since there is no heat generation or gunfire, it is very safe to handle. Furthermore, if compressed wood, which will be described later, is used as the physical change expanding material, the manufacturing process does not emit carbon dioxide, so the environmental load can be reduced.

[0015] It is preferable that at least a portion of the length of the physical change expansion material expands to 1.5 times or more 30 minutes after water is applied. If the length expands to 1.5 times or more 30 minutes after water is applied, a good crushing effect is easily obtained. The expansion after water is applied is preferably 1.8 times or more, and more preferably 2.0 times or more. The upper limit is not particularly limited, but in practice it is about 2.5 times.

[0016] The expansion (expansion rate) of the physical change expansion material can be determined by submerging the physical change expansion material in a container filled with 20°C water (preferably pure water), removing it after 30 minutes, measuring the length (B) of the most expanded part, and calculating "B / A" from the length (A) of the part before expansion that corresponds to the most expanded part. When measuring the expansion coefficient, the expansion coefficient of the physical change expansive material is measured in an unconstrained state. The physical change expansive material is in the form of a round bar having a diameter of 30 to 100 mm.

[0017] For example, when the physical change expansion material is in the shape of a round rod, the diameter before expansion corresponds to the above "A", and the maximum length after expansion (the long axis length perpendicular to the axial direction) corresponds to the above "B". The expansion rate can be adjusted, for example, by adjusting the compression rate when densified wood is produced using densified wood as an expanding material.

[0018] Examples of physical change expansive materials include densified wood, water swelling rubber, and water absorbing polymers, but densified wood is preferred from the viewpoint of reducing the environmental load and from the viewpoint of crushing performance. Densified wood is a material with a smaller CO2 emission unit and a smaller environmental load than conventional static crushing materials that mainly contain quicklime. In addition, since it can be made from domestic wood, it can contribute to the spread of domestic wood and the reduction of CO2.

[0019] The static crushing material according to this embodiment preferably contains 90% or more by volume of the physical change expansion material, and more preferably 100% by volume (the static crushing material is made of the physical change expansion material). By containing 90% or more by volume, the effect of the physical change expansion material is more easily exhibited. In addition to the physical change expansion material, for example, wood chips, Japanese paper or cloth, sand or gravel, limestone fine powder, silica fine powder, or other fillers can be included.

[0020] Densified wood has a density of 0.5 to 1.1 g / cm 3 Specifically, the wood is made of compressed wood that has been compressed to the above density. This compressed wood is wood that has been compressed by compressing it with a press or the like.

[0021] The density of physical change expansive materials (especially compressed wood) is 0.5 to 1.1 g / cm 3 It is preferable that the density is 0.5 to 1.1 g / cm 3 This allows for good crushing performance and weight reduction. The density is 0.75 to 1.05 g / cm 3 and preferably 0.8 to 1.0 g / cm 3 It is more preferable that: The density can be measured and determined in accordance with JIS Z 2101 (testing method for wood).

[0022] The static crushing material (particularly, the physically-changed expanding material) according to this embodiment is preferably a rod-shaped bar material. When the bar material is round, the diameter is preferably in the range of 30 mm to 100 mm, more preferably in the range of 40 mm to 80 mm. By being 30 mm or more, sufficient crushing force is easily obtained, and by being 100 mm or less, the crushing force is improved while the productivity of the physically-changed expanding material is improved, and a balance between these can be achieved. When the rod material has a shape other than a round bar, it is preferable that the circle-equivalent diameter of the cross section perpendicular to the length direction (axial direction) is within the above range.

[0023] [Method of manufacturing statically crushed material] A method for producing the statically crushed material according to this embodiment in which the physical change expansive material is compressed wood will be described below.

[0024] (Production of compressed lumber) Densified wood is (1) A drying process in which the raw wood is dried at 40 to 100°C to produce dried wood; (2) It is preferable that the wood be produced through a compression process in which dried wood is compressed in the thickness direction to form compressed wood. Each step will be described below.

[0025] (1) Drying process In the drying process, raw wood of a predetermined size is dried at 40 to 100°C to obtain dried wood. In the drying process, the raw wood is placed in a dryer set at a drying temperature of about 40 to 100°C and a wet-dry bulb temperature difference of about 1 to 30°C so that the moisture content is 10% by mass or less on average, and dried to obtain dried wood. The dried wood may be further subjected to a firing process at a high temperature of about 300°C for a short period of time. These drying and firing processes can be performed using a steam dryer, a hot water dryer, a pressure dryer, an electric dryer, or the like.

[0026] There is no particular limit to the type of raw wood, and any wood can be used. Specific examples include domestic coniferous trees such as red pine, black pine, yew, ginkgo, Japanese holly, Ezo spruce, Japanese kaya, larch, Japanese cedar, sawara, Japanese cedar, hemlock, Japanese dormosum, Japanese larches, Japanese cypress, Japanese cypress, cypress, Japanese cedar, Himekomatsu, and fir.

[0027] Domestic broad-leaved trees include blue ash, Japanese ash, red oak, asada, racemosum, silver maple, Chinese laurel, Japanese snowbell, Japanese walnut, persimmon, katsura, phellodendron amplexicaule, paulownia, camphor tree, chestnut, zelkova, Japanese laurel, cherry, Japanese walnut, hornbeam, linden, white oak, white birch, Machilus, boxwood, horse chestnut, poplar, false acacia, Japanese elm, Japanese alder, beech, magnolia, makamba, dogwood, Japanese oak, beech, Japanese bead tree, Japanese bead, Japanese ash, willow, and Japanese mulberry.

[0028] Examples of foreign conifers include agathis, Scots pine, Caribbean pine, Crinkle pine, southern yellow pine, spruce, Japanese cypress, Western cedar, Western hemlock, Japanese cypress, Japanese hiba, Douglas fir, Japanese fir, red pine, Japanese red pine, Honsun pine, and others, Japanese larch, ponderosa pine, radiata pine, Mexican cypress, redwood, and lodgepole pine.

[0029] Foreign hardwoods include Acacia mangium, Azobé, Apitong, African mahogany, Albizia, Yellow birch, Yellow poplar, Yellow meranti, Ipe, Iroko, Erima, Okoume, Obeche, Alder, Kapoor, Kapok, Camelele, Quince, Calophyllum, Gubas, Gelongan, Kempas, Cordia, Ebony, Kokrojua, Coconut, Rubber tree, Sapele, Jelutong, Jara, Jongkong, Silver beech, Spanish cedar, Scepter, Soft maples, Dark red maples, Some of the woods that can be used include Red Meranti, Taung, Dao, Tagayasan, Teak, Nato, Hard Maple, Basswood, Balsa, Beech, Hickory, Bubinga, Ply, Black Walnut, Black Cherry, Black Bean, Perpok, White Ash, White Oak, White Meranti, Makore, Mahogany, Maras, Mansonia, Melina, Mersawa, Merbau, Mengelis, Monkey Pot, Light Red Meranti, Labra, Ramin, Lignum Vita, Red Oak, and Rosewood.

[0030] The raw wood material is not particularly limited, but from the viewpoint of effective use of natural resources, thinned wood can be used, and a representative example is cedar.

[0031] (2) Compression process In the heat compression process, the dried wood is compressed in the thickness direction to produce compressed wood.

[0032] In the process of heating and compressing dried wood, it is preferable to raise the upper press platen relative to the lower press platen on the fixed side of the press platens, place the dried wood in the compression space formed by the upper and lower press platens, and then lower the upper press platen relative to the lower press platen so that the wood surface side of the tangential grain of the dried wood is abutted against the wood surface and compressed. The compression ratio in the compression process (thickness after compression / thickness before compression×100) is not particularly limited, but is preferably in the range of 30% to 60%.

[0033] The obtained compressed wood is preferably processed so that it can be inserted into holes drilled in concrete, boulders, or bedrock. Specific examples of this include processing the wood into rods or forming the wood into a sawdust-like shape. Rods are preferred from the viewpoint of obtaining a high crushing effect. The rods may have a cross-sectional shape that is circular, polygonal (triangle, square, pentagon, hexagon, etc.), or even star-shaped. The densified wood may be made of one material or multiple materials. For example, if the diameter of the drilled hole is large, the diameter of the densified wood must be large. In this case, two or three pieces of densified wood can be glued together in the axial direction with an adhesive to produce densified wood of the desired diameter.

[0034] [Static crushing method] The static crushing method according to this embodiment is a method in which the static crushing material is filled into a drilled hole in the object to be crushed and expanded by adding water. The object to be crushed is preferably a cement hardened body, boulders, or bedrock. The cement hardened body may be a cement based hardened body, a mortar hardened body, a concrete hardened body, or the like.

[0035] When the static crushing material is rod-shaped, it is preferable that the diameter of the hole drilled in the hardened cement body, boulder, or rock mass and the diameter of the static crushing material have the following formula (1) relationship. Diameter of hole drilled in concrete, boulders, or rock > diameter of static crushing material Equation (1)

[0036] Here, the difference between the diameter of the hole drilled in the concrete, boulder, or bedrock and the diameter of the static crushing material can be expressed as a clearance, and the clearance is expressed by the following formula (2). Clearance = diameter of hole drilled in concrete, boulders, or rock - diameter of static crushing material Formula (2)

[0037] In this embodiment, the clearance is not determined primarily by the size of the drilled hole diameter, but is preferably 5 mm or less, more preferably 3 mm or less. The clearance also plays a role in promoting the supply of water to the static crushing material, and if the clearance is 5 mm or less, the crushing effect will be large. It is preferable to install one static crushing material for one hole, but multiple static crushing materials may be installed in one hole.

[0038] In the static crushing method, it is preferable to carry out secondary crushing after primary crushing using a static crushing material (agent). Secondary crushing is the work of dismantling concrete, boulders, and rocks that have been cracked by primary crushing. A breaker is generally used as the secondary crusher, but a nibbler or ripper may also be used. In the conventional static crushing method using quicklime-based static crushing materials, the secondary crushing work could not be carried out until 10 hours after the static crushing material was injected. This is because the gun phenomenon may occur only after the hydration reaction of the quicklime-based static crushing material is completely completed and the heat of hydration has subsided, and sufficient time is required from a safety perspective. Therefore, in the conventional static crushing method using quicklime-based static crushing materials, the secondary crushing work was generally carried out the next day.

[0039] In addition, in the method using the quicklime-based static crushing material, the hydration reactivity of quicklime decreases especially at low temperatures below 10°C, and crushing can take 2 to 3 days, and at temperatures below 5°C, crushing can take more than a week. Conversely, in high temperature environments above 30°C, the gunshot phenomenon can occur. Furthermore, in this static crushing method, cracks are introduced by the primary crushing using the static crushing material, and then the building is demolished by secondary crushing. However, in order to work safely and avoid the risk of gunshot phenomenon, the secondary crushing work is standardized to be performed at least 10 hours after the injection of the static crushing material. Therefore, secondary crushing was generally performed the day after the primary crushing.

[0040] In contrast, the static crushing material according to the present embodiment does not generate heat due to hydration, so a safe static crushing method can be realized, and secondary crushing can be performed immediately after the completion of primary crushing, making it possible to complete the process from primary crushing to secondary crushing in one day. In other words, the static crushing method according to the present embodiment is not temperature-dependent in its operation, so it can perform the crushing process safely and efficiently.

[0041] The static crushing material described above is used, for example, to crush rocks, boulders, and unnecessary concrete structures. Note that "boulders" refer to masses of stone on the surface or underground, such as rocks that have broken off from outcrops and are scattered onto mountainsides or rivers. Therefore, depending on where the rocks fall, heavy machinery cannot reach them and removal work becomes difficult when they fall on slopes or the ground due to natural disasters such as earthquakes and volcanic eruptions. If the fallen rocks are left as they are, there is a risk of secondary disasters. In such cases, a static crushing material that can be safely used in places where crossing work is required during disasters and emergency response, or where multiple people are moving and crossing, is required, and the static crushing material of the present invention can be used optimally in such cases. EXAMPLES

[0042] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0043] [Experimental Example 1] <Experiments No. 1, 3, 5> (Preparation of static crushing material) The raw wood material, cedar boards (100 mm x 300 mm, 110 mm thick), was dried at 80°C using a pressure wood dryer to produce dried wood. The dried wood was compressed using a compressor to produce compressed wood (100 mm x 300 mm, thickness 55 mm, density 0.8 g / cm 3 A round bar with a diameter of 50 mm and a length of 300 mm was cut out perpendicular to the thickness direction from the side of this compressed wood, and then cut to a length of 100 mm.

[0044] (Expansion rate measurement) The cut compressed wood was submerged in a container filled with pure water at 20°C, and after 30 minutes it was taken out and the length of the most expanded part (B) was measured. The expansion rate was calculated by "B / A" using the length of the part before expansion that corresponds to the most expanded part (A). The compressed wood was left unconstrained during the measurement. Photographs of compressed wood before and after expansion are shown in Figure 1. As shown in Figure 1, A is the diameter (50 mm) and B is the long axis length of the ellipse.

[0045] (Evaluation of crushing time, etc.) Five holes, each 55 mm in diameter and 570 mm deep, were drilled into a 600 x 600 x 600 mm unreinforced concrete body. The holes were spaced 100 mm apart. After filling the holes with water, five of the static crushing materials prepared were immediately inserted after wetting them with water, and the primary crushing time was measured at 5°C, 20°C, and 30°C. The time required to start secondary crushing after primary crushing and the environmental load caused by the static crushing materials were also evaluated. The results are shown in Table 1. The assessment of the environmental impact was considered from the perspective of CO2 emissions during the production of static crushed materials, and the magnitude of CO2 emissions from raw materials and energy was considered. Conventional quicklime-based static crushed materials are obtained by burning the raw material limestone (calcium carbonate) at high temperatures in a furnace, so they emit large amounts of CO2 from both raw materials and energy. On the other hand, since compressed wood is obtained from wood, it emits less CO2 from both raw materials and energy.

[0046] <Experiments No. 2, 4, 6> Instead of using compressed wood as the static crushing material, quicklime-based static crushing material (manufactured by Pacific Materials, product name Blaister, powder form) was used, and 30 parts of water were added to 100 parts by mass of the quicklime-based static crushing material, mixed together to form a paste, and the quicklime-based static crushing material was filled into the five holes. Except for this, the primary crushing time was measured in the same manner as in Experiments 1, 3, and 5. In addition, the time to start secondary crushing and the magnitude of the environmental load caused by the quicklime-based static crushing material were also evaluated. The results are shown in Table 1.

[0047] [Table 1]

[0048] It can be seen that the static crushing material of this embodiment has a smaller temperature dependency, can shorten the time required to start secondary crushing, and has a smaller environmental impact than the conventional quicklime-based static crushing material.

[0049] [Experimental Example 2] In experiment No. 1, compressed wood was produced by changing the pressure (compression rate) of the pressurization process when producing compressed wood so that the expansion rate would be the ratio shown in Table 2, and the crushing time, etc. were evaluated. The results are shown in Table 2. The temperature for the primary crushing was 20°C.

[0050] [Table 2]

[0051] As shown in Table 2, an expansion rate of 1.5 times or more enabled the crushing time to be particularly shortened.

[0052] (Evaluation of diameter and hole spacing of statically crushed material) The same experiment was carried out using the previously described 600 x 600 x 600 mm unreinforced concrete hardened body, except that the diameter of the static crushing material, the number of drilled holes, and the distance between holes were changed as shown in Table 3. The results are shown in Table 3. In all cases, the drilled hole diameter was the diameter of the static crushing material + 5 mm.

[0053] [Table 3]

[0054] From Table 3, we can see that by increasing the diameter of the static crushing material, the number of holes to be drilled can be reduced and the distance between holes can be increased. This makes the crushing work more efficient. [Industrial Applicability]

[0055] INDUSTRIAL APPLICABILITY The present invention can be used for static crushing materials mainly used in the civil engineering and construction industries, in particular for static crushing methods for crushing brittle objects such as rocks or concrete without applying explosions or mechanical shocks.

Claims

1. A static crushing material containing a physical change expansion material that expands due to a physical change.

2. The static crushing material according to claim 1, wherein the length of at least a part of the physically changing expansion material expands to 1.5 times or more 30 minutes after water is applied thereto.

3. The static crushing material according to claim 1 or 2, wherein the physical change expansion material is rod-shaped.

4. The static crushing material according to claim 3, wherein the diameter of the physical change expansion material is 30 mm to 100 mm.

5. The static crushing material according to claim 1 or 2, wherein the physically changing expansive material is compressed wood.

6. A static crushing method comprising filling the static crushing material according to claim 1 or 2 into a drilled hole in an object to be crushed and adding water to cause it to expand.

7. 7. The static crushing method according to claim 6, wherein the object to be crushed is a hardened cement body, a boulder, or a bedrock.

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