Cavity filling composition, cavity filling material, and cavity filling material manufacturing method

Abstract

To provide a cavity filling material containing dry sludge powder, which exhibits appropriate fluidity before hardening and exhibits sufficient compressive strength after hardening.SOLUTION: A cavity filling material according to the present invention includes a dry sludge powder, a blast furnace slag powder, and a powder foaming agent, and further includes 90 to 130 pts.mass of water per 100 pts.mass of the dry sludge powder and the blast furnace slag powder. A cavity filling material manufacturing method according to the present invention includes a step of kneading a cavity filling material composition including a dry sludge powder, a blast furnace slag powder, and a powder foaming agent, and 90 to 130 pts.mass of water per 100 pts.mass of the dry sludge powder and the blast furnace slag powder, at a rotation speed of 750 rpm or more using a hand mixer equipped with an agitating blade having a crown or screw shape.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for a cavity filler, a cavity filler, and a method for manufacturing a cavity filler. More specifically, the present invention relates to a cavity filler containing dry sludge powder, a method for manufacturing the cavity filler, and a composition for a cavity filler used to obtain the cavity filler.

Background Art

[0002] Conventionally, it has been known to stabilize the ground by filling a cavity portion under a road surface with a cavity filler to close the cavity portion. The cavity filler is filled into the cavity portion, for example, through a boring hole drilled from the ground surface toward the cavity portion.

[0003] Also, in a tunnel constructed by the sheet pile method, it is known to suppress cracks and compressive failure in the tunnel by filling a cavity portion formed between the natural ground and the sheet pile with the cavity filler to close the cavity portion.

[0004] Furthermore, it is known to fill a cavity portion in various locations where backfilling with soil, sand, etc. is not possible with the cavity filler to close the cavity portion.

[0005] As the cavity filler, a bubble-containing cement composition containing bubbles such as air milk and air mortar is known (for example, Patent Document 1 below). Patent Document 1 below describes that the bubble-containing cement composition contains cement, a foaming agent, and water, and the contents of the cement, the foaming agent, and the water are each within a specific range in order to make the density of the bubble-containing cement composition within a predetermined numerical range.

[0006] Also, it is known to obtain dry sludge powder (hereinafter also referred to as dry sludge powder) from residual concrete or returned concrete generated from fresh concrete factories or construction sites (for example, Patent Document 2 below). Patent Document 2 below describes that dry sludge powder can be obtained by performing a washing step, a filtering step, a sieving step, a drying step, etc. on the residual concrete.

[0007] Furthermore, from the perspective of effectively utilizing the dry sludge powder obtained as described above, it is also known to use the dry sludge powder as a constituent component of premixed mortar (for example, Patent Document 3 below). Patent Document 3 below describes that the dry sludge powder is mixed with cement, fine aggregate, expansive agent, surfactant, and thickening agent to obtain premixed mortar.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] By the way, in recent years, in order to more effectively utilize the dry sludge powder, it has been desired to expand the uses of the dry sludge powder. For example, it has been proposed to use the dry sludge powder as a constituent component of the cavity filler.

[0010] The cavity portion under the road surface described above often occurs in the damaged portion of a buried pipe (for example, a sewer pipe etc.) buried underground. And, in order to facilitate filling the cavity portion with the cavity filler, although it is preferable that the cavity filler has high fluidity, if the fluidity is excessively high, the cavity filler may leak into the inside of the buried pipe through the damaged portion. Therefore, it is preferable that the cavity filler has appropriate fluidity such that it can be easily filled into the cavity portion and leakage into the inside of the buried pipe can be suppressed.

[0011] In addition, since the cavity filler is hardened after being filled in various cavity portions, it is necessary to exhibit sufficient compressive strength after hardening.

[0012] However, it is hard to say that sufficient studies have been made on making the cavity filler using the dried sludge powder as a constituent component have appropriate fluidity before hardening and exhibit sufficient compressive strength after hardening.

[0013] The present invention has been made to solve the above problems, and provides a cavity filler containing dried sludge powder, which has appropriate fluidity before hardening and exhibits sufficient compressive strength after hardening, a composition for cavity filler for obtaining the cavity filler, and a method for manufacturing the cavity filler.

Means for Solving the Problems

[0014] That is, the composition for cavity filler according to the present invention contains dried sludge powder, blast furnace slag powder, and a powder foaming agent.

[0015] According to such a configuration, in a state where the composition for cavity filler is mixed with water to form a cavity filler, it exhibits appropriate fluidity before hardening and sufficient compressive strength after hardening.

[0016] In addition, in the composition for a cavity filler according to the present invention, the dry sludge powder preferably has a Blaine specific surface area of 10,000 cm 2 / g or more.

[0017] According to such a configuration, in a state where the composition for a cavity filler is mixed with water to form a cavity filler, before curing, it exhibits appropriate fluidity, and after curing, in addition to exhibiting sufficient compressive strength, material separation (bleeding) between water and solid components (the dry sludge, the blast furnace slag powder, and the powder foaming agent, etc.) is suppressed.

[0018] In the composition for a cavity filler according to the present invention, the blast furnace slag powder preferably has a Blaine specific surface area of 3,500 cm 2 / g or more.

[0019] According to such a configuration, in a state where the composition for a cavity filler is mixed with water to form a cavity filler, before curing, it exhibits even more appropriate fluidity, and after curing, it exhibits even more sufficient compressive strength.

[0020] In the composition for a cavity filler according to the present invention, the powder foaming agent is preferably an α-olefin sulfonate.

[0021] According to such a configuration, in a state where the composition for a cavity filler is mixed with water to form a cavity filler, before curing, it exhibits even more appropriate fluidity, and after curing, it exhibits even more sufficient compressive strength.

[0022] In the composition for a cavity filler according to the present invention, it is preferable that, based on 100 parts by mass of the dry sludge powder and the blast furnace slag powder, the dry sludge powder is contained in an amount of 20 parts by mass or more and 90 parts by mass or less, and the blast furnace slag powder is contained in an amount of 10 parts by mass or more and 80 parts by mass or less.

[0023] According to such a configuration, in a state where the composition for the cavity filler is mixed with water to form a cavity filler, before curing, it exhibits more appropriate fluidity, and after curing, it exhibits more sufficient compressive strength.

[0024] The cavity filler according to the present invention contains dry sludge powder, blast furnace slag powder, and a powder foaming agent, and further contains 90 parts by mass or more and 130 parts by mass or less of water with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder.

[0025] According to such a configuration, the cavity filler exhibits appropriate fluidity before curing and sufficient compressive strength after curing.

[0026] In the cavity filler according to the present invention, the dry sludge powder preferably has a Blaine specific surface area of 10,000 cm 2 / g or more.

[0027] According to such a configuration, in addition to the cavity filler exhibiting appropriate fluidity before curing and sufficient compressive strength after curing, material separation (bleeding) between water and solid components (the dry sludge powder, the blast furnace slag powder, the powder foaming agent, etc.) is suppressed.

[0028] The method for manufacturing the cavity filler according to the present invention includes a step of kneading, at a rotation speed of 750 rpm or more, a composition for a cavity filler containing dry sludge powder, blast furnace slag powder, and a powder foaming agent, and 90 parts by mass or more and 130 parts by mass or less of water with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder, using a hand mixer equipped with a stirring blade having a crown shape or a screw shape.

[0029] According to such a configuration, the resulting cavity filling material can be made to exhibit appropriate fluidity before curing and sufficient compressive strength after curing.

[0030] In the method for manufacturing a cavity filling material according to the present invention, It is preferable that, with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder, the dry sludge powder is contained in an amount of 20 parts by mass or more and 90 parts by mass or less, and the blast furnace slag powder is contained in an amount of 10 parts by mass or more and 80 parts by mass or less.

[0031] According to such a configuration, the resulting cavity filling material can be made to exhibit even more appropriate fluidity before curing and even more sufficient compressive strength after curing.

[0032] In the method for manufacturing a cavity filling material of the present invention, The dry sludge powder preferably has a Blaine specific surface area of 10,000 cm 2 / g or more.

[0033] According to such a configuration, in addition to the resulting cavity filling material being able to exhibit appropriate fluidity before curing and sufficient compressive strength after curing, it is possible to suppress the occurrence of material separation (bleeding) between water and solid components (the dry sludge powder, the blast furnace slag powder, and the powder foaming agent, etc.).

Advantages of the Invention

[0034] According to the present invention, it is possible to provide a cavity filling material containing dry sludge powder, which exhibits appropriate fluidity before curing and sufficient compressive strength after curing, a composition for a cavity filling material for obtaining the cavity filling material, and a method for manufacturing the cavity filling material.

Embodiments for Carrying Out the Invention

[0035] Hereinafter, an embodiment of the present invention will be described.

[0036] [Composition for cavity filler] The composition for cavity filler according to this embodiment contains dry sludge powder, blast furnace slag powder, and a powder foaming agent. Note that both the dry sludge powder and the blast furnace slag powder are classified as binders (abbreviated as B).

[0037] (Dry sludge powder) The dry sludge powder can be obtained by recovering sludge water from surplus concrete or returned concrete generated from a fresh concrete plant or a construction site, or washing wastewater generated from a ready-mix concrete plant, extracting the cake component (solid component) from the sludge water, and then drying and pulverizing the cake component. Note that the sludge water means a slurry-like substance containing cement and fine fine aggregate (for example, fine aggregate with a particle size of less than 300 μm) as solid components. That is, the sludge water does not contain coarse aggregate and large fine aggregate (for example, fine aggregate with a particle size of 300 μm or more). Note that the particle size of the fine aggregate here refers to the value obtained by measuring using a laser diffraction particle size distribution analyzer.

[0038] Examples of the cement include Portland cements such as ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, medium-heat Portland cement, sulfate-resistant Portland cement, and white Portland cement; blended cements such as fly ash cement and silica cement; and known cements such as super-high-early-strength cement and alumina cement. Note that the cement may be used alone as one of the above, or two or more of them may be used in combination.

[0039] The water content of the dry sludge powder is preferably 7% by mass or less, more preferably 6% by mass or less, and still more preferably 5% by mass or less.

[0040] The water content rate of the dry sludge powder is calculated from the following formula (1). Water content (mass %) = 100 × (mass of water in dry sludge powder) / {(mass of absolutely dry dry sludge powder) + (mass of water in dry sludge powder)} ···(1)

[0041] The dry sludge powder preferably contains 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and even more preferably 95% by mass or more of the cement or the compound derived from the cement. The balance of the dry sludge powder includes fine aggregates (for example, aggregates having a particle size of less than 300 μm). Examples of the compound derived from the cement include calcium hydroxide, calcium silicate hydrate, calcium aluminate hydrate, calcium carbonate, and the like.

[0042] The dry sludge powder preferably has a specific surface area of 5000 cm 2 / g or more, more preferably 7000 cm 2 / g or more, still more preferably 9000 cm 2 / g or more, and even more preferably 10000 cm 2 / g or more. Further, the dry sludge powder may have a specific surface area of 11000 cm 2 / g or more, 12000 cm 2 / g or more, or 13000 cm 2 / g or more. The upper limit of the specific surface area of the dry sludge powder is usually 20000 cm 2 / g.

[0043] When the specific surface area of the dry sludge powder is 10000 cm 2 / g or more, in a state where the composition for a void filler containing the dry sludge powder is mixed with water to form a void filler, material separation (bleeding) in the void filler can be suppressed.

[0044] The specific surface area of the dried sludge powder can be measured according to the method described in JIS R 5201:2015, "Physical Testing Methods for Cement, 8 Powder Fineness Test, 8.1 Specific Surface Area Test".

[0045] The dried sludge powder may have a density of 2.4 g / cm 3 or more, or a density of 2.5 g / cm 3 or more, or a density of 2.6 g / cm 3 or more. Also, the upper limit value of the density of the dried sludge powder is usually 2.8 g / cm 3 .

[0046] The density of the dried sludge powder can be measured according to the method described in JIS R 5201:2015, "Physical Testing Methods for Cement, 7 Density Test", or using a gas pycnometer (for example, Ultra Pycnometer 1000 manufactured by Quantachrome) according to the gas displacement method.

[0047] The dried sludge powder preferably has a d10 of 4.0 μm or more and 5.5 μm or less, more preferably a d10 of 4.0 μm or more and 5.3 μm or less, and even more preferably a d10 of 4.0 μm or more and 5.0 μm or less.

[0048] Note that d10 means the particle size when the passing mass percentage is 10% in a particle size cumulative curve with the horizontal axis being the particle size (μm) and the vertical axis being the passing mass percentage (%). Also, d50 means the particle size when the passing mass percentage is 50% in the particle size cumulative curve, and d90 means the particle size when the passing mass percentage is 90% in the particle size cumulative curve.

[0049] The d10, d50, and d90 of the dried sludge powder can be determined by measuring using a laser diffraction particle size distribution analyzer (for example, MT3000 manufactured by Microtrac BEL).

[0050] The dry sludge powder preferably has a mass ratio of passing through a sieve with an opening of 20 μm of 45% or more, more preferably 48% or more, and even more preferably 50% or more. Further, the mass ratio of the dry sludge powder passing through a sieve with an opening of 20 μm may be 80% or less, 70% or less, or 60% or less.

[0051] The dry sludge powder preferably has a mass ratio of passing through a sieve with an opening of 10 μm of 25% or more, more preferably 27% or more, and even more preferably 29% or more. Further, the mass ratio of the dry sludge powder passing through a sieve with an opening of 10 μm may be 50% or less, 40% or less, or 35% or less.

[0052] The dry sludge powder preferably has a mass reduction rate W1 between 400°C and 500°C of 0.2% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 4.5% by mass or less, and even more preferably 1.0% by mass or more and 4.0% by mass or less. Further, the dry sludge powder preferably has a mass reduction rate W2 between 600°C and 800°C of 7.0% by mass or more and 20% by mass or less, more preferably 7.8% by mass or more and 18% by mass or less, and even more preferably 8.0% by mass or more and 15% by mass or less.

[0053] The mass reduction rates W1 and W2 can be obtained from the measured thermogravimetric values by measuring the thermogravimetry under a nitrogen atmosphere at a heating rate of 10.0°C / min using a differential thermal-thermogravimetry simultaneous measurement device (for example, TG-8120 manufactured by Rigaku Corporation).

[0054] The composition for a cavity filler according to the present embodiment preferably contains 20 parts by mass or more and 90 parts by mass or less of the dry sludge powder with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder.

[0055] (Blast furnace slag powder) It is important that the composition for a cavity filler according to this embodiment contains the blast furnace slag powder in addition to the dried sludge powder. As described above, since the dried sludge powder is the cake component (solid component) recovered from sludge water, in the silicate phase and the interstitial phase in the cement contained in the dried sludge powder, the hydration reaction has often proceeded to a certain extent. On the other hand, the blast furnace slag powder is obtained by leaving the molten slag produced from the blast furnace in the cooling yard (left in the atmosphere) for slow cooling, or by spraying a large amount of pressurized water onto the molten slag for rapid cooling. And the blast furnace slag powder obtained by slow cooling has not been in contact with water, and the blast furnace slag powder obtained by spraying pressurized water for rapid cooling has a lower frequency of contact with water compared to the dried sludge powder. Therefore, it is considered that a large amount of silicate phase and interstitial phase contributing to the hydration reaction remain in the blast furnace slag powder. Therefore, by combining the dried sludge powder and the blast furnace slag powder, the compressive strength after hardening can be sufficiently exhibited compared to the case where the dried sludge powder is used alone. Further, by combining the dried sludge powder and the blast furnace slag powder, when mixed with water to form a cavity filler, appropriate fluidity can be exhibited.

[0056] Examples of the blast furnace slag powder include granulated blast furnace slag powder and slowly cooled blast furnace slag powder. In the composition for a cavity filler according to this embodiment, it is preferable to use the granulated blast furnace slag powder as the blast furnace slag powder. The granulated blast furnace slag powder is blast furnace slag obtained by spraying a large amount of pressurized water onto the molten slag produced from the blast furnace for rapid cooling, and the slowly cooled blast furnace slag powder is blast furnace slag obtained by leaving the molten slag produced from the blast furnace in the cooling yard for slow cooling.

[0057] The blast furnace slag powder preferably has a Blaine specific surface area of 3500 cm 2 / g or more, more preferably has a Blaine specific surface area of 3800 cm 2 / g or more, and most preferably has a Blaine specific surface area of 4000 cm 2It is more preferable to have a Blaine specific surface area of / g or more. The upper limit of the Blaine specific surface area of the blast furnace slag powder is usually 10,000 cm 2 / g. By setting the specific surface area of the blast furnace slag powder within the above numerical range, when the composition for the void filler is mixed with water to form a void filler, the compressive strength after curing of the void filler can be further increased. Also, the void filler can be made to have more appropriate fluidity.

[0058] The Blaine specific surface area of the blast furnace slag powder can be determined in the same manner as the Blaine specific surface area of the dried sludge powder.

[0059] The blast furnace slag powder may have a density of 2.4 g / cm 3 or more, or may have a density of 2.5 g / cm 3 or more, or may have a density of 2.6 g / cm 3 or more. The upper limit of the density of the blast furnace slag powder is usually 2.9 g / cm 3 .

[0060] The density of the blast furnace slag powder can be determined in the same manner as the density of the dried sludge powder.

[0061] The composition for the void filler according to this embodiment preferably contains 10 parts by mass or more and 80 parts by mass or less of the blast furnace slag powder with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder.

[0062] (Powder foaming agent) As the powder foaming agent, for example, an aliphatic alcohol-based powder foaming agent can be used. By containing an aliphatic alcohol-based powder foaming agent, the composition for a cavity filler according to this embodiment can stably maintain air bubbles in the composition for a cavity filler. As the aliphatic alcohol-based powder foaming agent, it is preferable to use an α-olefin sulfonate. The α-olefin sulfonate preferably has 10 or more and 18 or less carbon atoms in the α-olefin moiety, more preferably 14 or more and 16 or less carbon atoms. Examples of the α-olefin sulfonate include sodium α-olefin sulfonate. Commercially available products of the sodium α-olefin sulfonate include, for example, the product name "Lipolan PJ-400" manufactured by Lion Corporation, and the product name "Lipolan PB-800CJ" manufactured by Lion Specialty Chemicals Co., Ltd. The powder foaming agent may be used alone or in combination of two or more.

[0063] The composition for a cavity filler according to this embodiment preferably contains 0.05 parts by mass or more of the powder foaming agent with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder. Further, the composition for a cavity filler according to this embodiment may contain 0.2 parts by mass or more of the powder foaming agent with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder, or may contain 0.5 parts by mass or more of the powder foaming agent, or may contain 0.7 parts by mass or more of the powder foaming agent, or may contain 1.0 parts by mass or more of the powder foaming agent, or may contain 1.5 parts by mass or more of the powder foaming agent. Furthermore, the composition for a cavity filler according to this embodiment may contain 2.0 parts by mass or less of the powder foaming agent with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder, or may contain 1.7 parts by mass or less.

[0064] (Cavity filler) The cavity filler according to this embodiment contains dried sludge powder, blast furnace slag powder, and a powder foaming agent. Further, the cavity filler according to this embodiment contains 90 to 130 parts by mass of water with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder. In other words, in the cavity filler according to this embodiment, the water binder ratio (W / B×100) is 90% or more and 130% or less. Note that the mass of the binder means the value obtained by adding up the mass of the dried sludge powder and the mass of the blast furnace slag powder. In the cavity filler according to this embodiment, solids such as the dried sludge powder, the blast furnace slag powder, and the powder foaming agent are mixed with the water. More specifically, the solids are mixed in a state of being suspended in the water.

[0065] The cavity filler according to this embodiment is configured by mixing a composition for the cavity filler according to this embodiment in a suspended state in a predetermined amount of water. Therefore, as the dried sludge powder, the blast furnace slag powder, and the powder foaming agent, those described above can be used.

[0066] The cavity filler according to this embodiment preferably contains 20 to 90 parts by mass of the dried sludge powder with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder. Further, the cavity filler according to this embodiment preferably contains 10 to 80 parts by mass of the blast furnace slag powder with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder.

[0067] The cavity filling material according to this embodiment preferably contains 0.05 parts by mass or more of the powder foaming agent with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder. Further, the cavity filling material according to this embodiment may contain 0.2 parts by mass or more of the powder foaming agent with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder, or may contain 0.5 parts by mass or more of the powder foaming agent, or may contain 0.7 parts by mass or more of the powder foaming agent, or may contain 1.0 parts by mass or more of the powder foaming agent, or may contain 1.5 parts by mass or more of the powder foaming agent. Furthermore, the cavity filling material according to this embodiment may contain 2.0 parts by mass or less of the powder foaming agent with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder, or may contain 1.7 parts by mass or less.

[0068] The cavity filling material according to this embodiment may contain various additives other than the dry sludge powder, the blast furnace slag powder, and the powder foaming agent. Examples of such additives include various known admixtures and admixture agents. Note that the admixture means a material included in the finished volume of the cavity filling material, and the admixture agent means a material (pharmaceutical material) not included in the finished volume of the cavity filling material. The admixture is usually contained in an amount of 5 parts by mass or more with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder, and the admixture agent is usually contained in an amount of less than 1 part by mass with respect to 100 parts by mass of the dry sludge powder and the blast furnace slag powder.

[0069] Examples of the admixture include fly ash, silica fume, cement kiln dust, blast furnace fume, converter slag powder, hemihydrate gypsum, expansive agent, limestone powder, quicklime powder, dolomite powder, sodium-type bentonite, calcium-type bentonite, attapulgite, sepiolite, activated clay, acid clay, allophane, imogolite, shirasu (volcanic ash), shirasu balloon, kaolinite, metakaolin (calcined clay), synthetic zeolite, artificial zeolite, artificial zeolite, mordenite, clinoptilolite, etc. The admixture may be used alone or in combination of two or more kinds.

[0070] Examples of the admixture agent include AE agent, AE water reducing agent, thickening agent, fluidizing agent, separation reducing agent, setting retarder (e.g., tartaric acid, etc.), setting accelerator (e.g., aluminum sulfate, etc.), flash setting agent, shrinkage reducing agent, foaming agent, waterproof agent, etc. The admixture agent may be used alone or in combination of two or more kinds.

[0071] The cavity filling material according to this embodiment may have a wet density of 0.6 g / cm 3 or more, or may have a wet density of 0.7 g / cm 3 or more, or may have a wet density of 0.8 g / cm 3 or more, or may have a wet density of 0.9 g / cm 3 or more, or may have a wet density of 1.0 g / cm 3 or more, or may have a wet density of 1.1 g / cm 3 or more, or may have a wet density of 1.2 g / cm 3 or more. Also, the cavity filling material according to this embodiment may have a wet density of 1.5 g / cm 3 or less, or may have a wet density of 1.4 g / cm 3 or less, or may have a wet density of 1.3 g / cm 3It may have the following wet density. When the wet density is within the above numerical range, the load applied to the ground in the cavity part can be reduced, so that the occurrence of secondary settlement can be suppressed. The wet density can be measured in accordance with the unit volume mass test of JIS A 1171:2016 "Test Methods for Polymer Cement Mortar" 6.4.

[0072] The cavity filling material according to the present embodiment preferably has a cylinder flow value of 350 mm or less, more preferably has a cylinder flow value of 250 mm or less, and even more preferably has a cylinder flow value of 200 mm or less. When the cylinder flow value is within the above numerical range, it is possible to suppress the cavity filling material from leaking out of the cavity part. In particular, when the cylinder flow value is 200 mm or less, it is possible to more sufficiently suppress the cavity filling material from leaking out of the cavity part. Further, the cavity filling material according to the present embodiment preferably has a cylinder flow value of 80 mm or more, and more preferably has a cylinder flow value of 100 mm or more. When the cylinder flow value is within the above numerical range, the fillability of the cavity filling material into the cavity part can be sufficiently ensured. The cylinder flow value can be measured in accordance with the flow test described in NEXCO test method 313.

[0073] The cavity filling material according to the present embodiment has a compressive strength (uniaxial compressive strength) at 7 days of age of 125 kN / m 2 or more, preferably 300 kN / m 2 or more, more preferably 500 kN / m 2 or more, more preferably 800 kN / m 2 or more, more preferably 1000 kN / m 2 or more. The upper limit value of the compressive strength at 7 days of age is 1500 kN / m 3 or less.

[0074] The cavity filling material according to this embodiment preferably has a compressive strength (uniaxial compressive strength) at 28 days of age of 450 kN / m 2 or more, more preferably 650 kN / m 2 or more, even more preferably 800 kN / m 2 or more, even more preferably 1000 kN / m 2 or more, even more preferably 1300 kN / m 2 or more, even more preferably 1800 kN / m 2 or more, even more preferably 2000 kN / m 2 or more, even more preferably 2500 kN / m 2 or more, even more preferably 3000 kN / m 2 or more, even more preferably 3500 kN / m 2 or more. The upper limit value of the compressive strength at 28 days of age is 5000 kN / m 2 .

[0075] By having the compressive strength at 7 days of age and the compressive strength at 28 days of age within the above numerical ranges, the cavity filling material according to this embodiment exhibits sufficient compressive strength after hardening. The compressive strength at 7 days of age and the compressive strength at 28 days of age can be measured by a method in accordance with the uniaxial compression test method for soil described in JIS A 1216.

[0076] (Method for manufacturing cavity filling material) The method for manufacturing the cavity filling material according to this embodiment includes a composition for cavity filling material containing dried sludge powder, blast furnace slag powder, and a powder foaming agent, and 90 to 130 parts by mass of water with respect to 100 parts by mass of the dried sludge powder and the blast furnace slag powder. The method has a kneading step of kneading at a rotational speed of 750 rpm or more using a hand mixer equipped with a stirring blade having a crown type or screw type shape. Hereinafter, the step of kneading the composition for cavity filling material and the water is also simply referred to as the kneading step.

[0077] The hand mixer used in the kneading process is a small-sized mixer, which is easy to transport to the construction site. Therefore, when the kneading process is carried out using such a small-sized mixer, at the construction site, the cavity filling material can be obtained by kneading the composition for the cavity filling material and the water. That is, the cavity filling material can be obtained with good mobility.

[0078] The hand mixer is provided with stirring blades. Examples of the shape of the stirring blades include a crown type (made of stainless steel), a screw type (made of aluminum), etc. Among these, the shape of the stirring blades is preferably a crown type (made of stainless steel).

[0079] Also, the diameter of the stirring blades is preferably 90 mm or more and 200 mm or less, and more preferably 100 mm or more and 180 mm or less.

[0080] Examples of the hand mixer include UT1305 manufactured by Makita Corporation.

[0081] In the kneading process, the rotation speed of the hand mixer is 750 rpm or more, preferably 900 rpm or more, and more preferably 1000 rpm or more. By carrying out the kneading process at such a rotation speed, the cavity filling material can be obtained in a state where solid components such as the dry sludge powder, the blast furnace slag powder, and the powder foaming agent are sufficiently suspended in the water.

[0082] Note that, as one aspect, the kneading process may be carried out by kneading the composition for the cavity filling material and the water using, for example, a grout mixer in addition to the hand mixer.

[0083] From the viewpoint of improving workability, the kneading time in the kneading process is preferably 2.0 min or more and 3.0 min or less.

[0084] The volume of the cavity filling material after kneading the composition for the cavity filling material and the water may be 1.18 L or more, or may be 1.50 L or more, per 1 kg of the composition for the cavity filling material. Further, the volume of the cavity filling material may be 2.50 L or less, or may be 1.40 L or less. In particular, when the volume of the cavity filling material is 1.18 L or more and 1.40 L or less, more cavity portions can be filled using a small amount of the composition for the cavity filling material.

[0085] From the viewpoint of suppressing leakage of the cavity filling material from the cavity portion, it is preferable that the curing time of the cavity filling material at 20 °C is 5.0 h or less. Note that the curing time means the end time among the setting times.

[0086] Note that the composition for the cavity filling material, the cavity filling material, and the method for manufacturing the cavity filling material according to the present invention are not limited to the above-described embodiment. Further, the composition for the cavity filling material, the cavity filling material, and the method for manufacturing the cavity filling material according to the present invention are not limited by the above-described effects. Various modifications can be made to the composition for the cavity filling material, the cavity filling material, and the method for manufacturing the cavity filling material according to the present invention without departing from the gist of the present invention.

Examples

[0087] Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. The following examples are for further explaining the present invention and do not limit the scope of the present invention.

[0088] <Manufacture of Cavity Filling Material> First, each powder component (first dried sludge powder, second dried sludge powder, third dried sludge powder, blast furnace slag powder, and powder foaming agent) was mixed in the formulation shown in Table 1 below to obtain a composition for a cavity filling material. Next, the composition for the cavity filling material and water were kneaded at the water binder ratio (W / B×100) shown in Table 1 to obtain cavity filling materials according to Examples 1 to 17 and a cavity filling material according to Comparative Example 1. The kneading of the composition for the cavity filling material and water was carried out using a hand mixer (Makita Corporation's "UT1305", shape of the stirring blade: crown type, diameter of the stirring blade: 105 mm) under the condition of a rotation speed of 1100 rpm. Also, the kneading time with the hand mixer was set to 2.0 min in all examples.

[0089] The details of each powder component shown in Table 1 are as follows. (Dried sludge powder) · First dried sludge powder: Dried sludge powder with a Blaine specific surface area of 13500 cm 2 / g · Second dried sludge powder: Dried sludge powder with a Blaine specific surface area of 10210 cm 2 / g · Third dried sludge powder: Dried sludge powder with a Blaine specific surface area of 5760 cm 2 / g (Blast furnace slag powder) Granulated blast furnace slag powder (Blaine specific surface area: 4700 cm 2 / g) (Powder foaming agent) Sodium α-olefin sulfonate ("Lipolan PJ-400" manufactured by Lion Corporation)

[0090] In Table 1 below, the dried sludge powder is abbreviated as STC. More specifically, the first dried sludge powder is abbreviated as STC1, the second dried sludge powder is abbreviated as STC2, and the third dried sludge powder is abbreviated as STC3. Also, in Table 1 below, the blast furnace slag powder is abbreviated as BSF.

[0091]

Table 1

[0092] In addition, the results of evaluating the physical properties of the first dried sludge powder (STC1), the second dried sludge powder (STC2), the third dried sludge powder (STC3), and blast furnace slag powder (BSF) are shown in Table 2 below. The density, Blaine specific surface area, d10, d50, and d90 shown in Table 2 below were measured according to the methods described in the section of the above embodiment. Also, in Table 2 below, 20μm pass means the ratio of the powder passing through a sieve with an opening of 20μm, and 10μm pass means the ratio of the powder passing through a sieve with an opening of 10μm.

[0093] [Table 2]

[0094] Furthermore, regarding the second dried sludge powder (STC2) and the third dried sludge powder (STC3), the results of measuring the mass loss rate W1 between 400 and 500°C and the mass loss rate W2 between 600 and 800°C are shown. The mass loss rate W1 and the mass loss rate W2 were measured according to the methods described in the section of the above embodiment.

[0095] [Table 3]

[0096] For the cavity fillers of Examples 1 to 17 and the cavity filler according to Comparative Example 1, the wet density, cylinder flow, compressive strength at 7 days of age, and compressive strength at 28 days of age were measured. The measurement results are shown in Table 4 below. The wet density, cylinder flow, compressive strength at 7 days of age, and compressive strength at 28 days of age were measured according to the methods described in the section of the above embodiment.

[0097] [Table 4]

[0098] From Table 4, it is understood that the cavity fillers according to Examples 1 to 17 show relatively low values with a maximum cylinder flow value of 340 mm. Further, the cavity fillers according to Examples 1 to 17 show relatively high values with a minimum compressive strength of 456.0 kN / m at 28 days of age. 2 On the other hand, although the cavity filler according to Comparative Example 1 shows a relatively low value of 268 mm for the cylinder flow value, it is understood that the compressive strength at 28 days of age shows a relatively low value of 271.9 kN / m. 2 From this result, it is understood that the cavity fillers according to Examples 1 to 17 can be easily filled into the cavity part before hardening, and leakage into the inside of the buried pipe (for example, a sewer pipe) is suppressed, and after hardening, they show sufficient compressive strength. Further, it is expected that the cavity fillers according to Examples 1 to 12, which show even lower values with a cylinder flow value of 200 mm or less, will be particularly effective in suppressing leakage from the cavity part, more specifically, leakage into the inside of the buried pipe. Furthermore, no material separation was observed in the cavity fillers according to Examples 1 to 12. Therefore, it is considered that the cavity fillers according to Examples 1 to 12 can be filled into the cavity part in a state where the composition for cavity filler is sufficiently suspended in water.

Claims

1. A composition for a cavity filler, comprising dry sludge powder, blast furnace slag powder, and a powder foaming agent.

2. The dried sludge powder has a Blaine specific surface area of 10,000 cm ２ / g or more The composition for a cavity filler according to Claim 1.

3. The blast furnace slag powder has a Blaine specific surface area of 3500 cm ２ / g or more The composition for a cavity filler according to Claim 1 or 2.

4. The powder foaming agent is an α-olefin sulfonate. The composition for a cavity filler according to Claim 1 or 2.

5. Based on 100 parts by mass of the dry sludge powder and the blast furnace slag powder, the composition for a cavity filler according to Claim 1 or 2 contains 20 to 90 parts by mass of the dry sludge powder and 10 to 80 parts by mass of the blast furnace slag powder.

6. A cavity filler, comprising dry sludge powder, blast furnace slag powder, and a powder foaming agent, and further containing 90 to 130 parts by mass of water based on 100 parts by mass of the dry sludge powder and the blast furnace slag powder.

7. The dried sludge powder has a Blaine specific surface area of 10,000 cm ２ / g or more The cavity filler according to Claim 6.

8. A method for manufacturing a cavity filler, comprising a step of kneading a composition for a cavity filler containing dry sludge powder, blast furnace slag powder, and a powder foaming agent, and 90 to 130 parts by mass of water based on 100 parts by mass of the dry sludge powder and the blast furnace slag powder, using a hand mixer equipped with a stirring blade having a crown shape or a screw shape, at a rotation speed of 750 rpm or more.

9. Based on 100 parts by mass of the dry sludge powder and the blast furnace slag powder, the method for manufacturing a cavity filler according to Claim 8 contains 20 to 90 parts by mass of the dry sludge powder and 10 to 80 parts by mass of the blast furnace slag powder.

10. The dried sludge powder has a Blaine specific surface area of 10,000 cm ２ / g or more The method for manufacturing a cavity filler according to Claim 8 or 9.

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