Dust-reducing agent for cement-based material
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KAO CORP
- Filing Date
- 2023-07-10
- Publication Date
- 2026-06-29
Abstract
Description
[Technical field]
[0001] The present invention relates to a dust-reducing agent for cement-based systems and a cement-based solidification material. [Background technology]
[0002] Conventionally, methods such as roadbed and subgrade stabilization methods and ground improvement methods (constructed at the current site) that use cement as a soil stabilizing material (hereafter referred to as solidification material) have been widely implemented because they can effectively utilize low-quality local soil and are more economical than other methods. In addition, it is expected that the need for these methods will further increase in the future due to the need to reduce construction waste soil.
[0003] However, in the conventional methods mentioned above, the fine powder cement-based solidification material scatters when it is spread, so from the perspective of protecting the surrounding environment and the working environment, there is a strong desire to suppress or reduce the generation of dust in soil stabilization work. In particular, from a materials perspective, there is a desire to develop a dust-proof solidification material that can be used with normal construction methods.
[0004] Patent Document 1 discloses a method for producing a cement-based solidification material that generates little dust when spread and has good storage stability, the method comprising the step of mixing an aqueous solution containing a predetermined concentration of an alkylene oxide adduct (A) of a monohydric alcohol having 1 to 6 carbon atoms, the average number of moles of alkylene oxide added being 5 to 40, and an alcohol-based compound (B) other than (A), with a hydraulic powder so that the ratio of (A), (B) and water to the hydraulic powder is a specific ratio. Patent Document 2 discloses a dust-suppressing solidification material that is made by adding an aqueous solution of a premix of 1-4 mass% alcohol-based compound, 0.1-0.5 mass% setting retarder, and 0.5-1.5 mass% water to a cement-based solidification material, and that is inexpensive, highly safe, has a long usable life necessary for large-scale construction work, and has sufficient solidification characteristics. Patent Document 3 discloses a dust-inhibiting composition that contains starches, a hydration retarder, and an alcohol compound, and that when a hydraulic powdery composition (a powdery solidifying material having dust-inhibiting properties) is prepared by mixing a solidifying material with water, the hydraulic powdery composition is not likely to harden during storage, sufficiently inhibits dust generation during use, and has uniform physical properties after hardening. Patent Document 4 discloses an additive for anti-dust scattering coating water, which contains fructose as a water retention agent, glycerin as a moisture retention agent, a surfactant as a penetration enhancer, and a sugar alcohol, and is added to and dissolved in coating water and then applied to a mineral fiber application layer. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] JP 2009-114378 A [Patent Document 2] JP 2004-292528 A [Patent Document 3] JP 2016-69464 A [Patent Document 4] JP 2010-202779 A Summary of the Invention [Problem to be solved by the invention]
[0006] However, in Patent Documents 2 and 3, sugars are used as cement-based solidification materials that reduce dust, and sugars have a dust-reducing effect by suppressing the hydration reaction between water and cement. However, sugars act as a setting retarder for cement, so that the strength development is low when the cement-based solidification material is mixed with the ground. In addition, sugars are weak against acids, alkalis, and heat, and cause the Maillard reaction and caramelization, so there is a problem that the storage stability decreases due to color change (coloring) over time and decomposition of sugar after storage in an aqueous solution as a dust-reducing agent. In addition, sugars and alcohol-based compounds used in Patent Documents 1 to 4 are organic substances, so there are problems with the performance of reducing dust when mixed with the ground and the strength of the ground improvement body decreasing after storage of the cement-based solidification material added to cement (alkali) as a dust-reducing agent containing these.
[0007] The present invention provides a dust-reducing agent for cement-based solidification materials, which has good storage stability and can reduce dust when the cement-based solidification material to which it is added is mixed with the ground even after storage, and can suppress a decrease in strength of the ground improvement material; and a cement-based solidification material, which can reduce dust when the cement-based solidification material is mixed with the ground even after storage, and can suppress a decrease in strength of the ground improvement material. [Means for solving the problem]
[0008] The present invention relates to a dust-reducing agent for cement systems, which contains (a) a sugar alcohol (hereinafter referred to as component (a)), (b) an alcohol-based compound (excluding component (a)) (hereinafter referred to as component (b)), and water.
[0009] The present invention also relates to a cement-based solidification material containing the dust-reducing agent for cement-based systems of the present invention and cement.
[0010] The present invention also relates to a method for reducing dust in a powdery composition containing cement, comprising mixing a dust-reducing agent for cement-based systems, which contains component (a), component (b), and water, with the powdery composition. Effect of the Invention
[0011] According to the present invention, there is provided a dust-reducing agent for cement-based solidification materials which has good storage stability and which can reduce dust when the cement-based solidification material to which it is added is mixed with the ground even after storage, and which can suppress a decrease in strength of the ground improvement material, and a cement-based solidification material which can reduce dust when the cement-based solidification material is mixed with the ground even after storage, and which can suppress a decrease in strength of the ground improvement material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The present inventors have found that it is possible to provide a dust-reducing agent for cement-based solidification materials that has good storage stability, reduces dust when the cement-based solidification material to which it is added is mixed with the ground even after storage, and can suppress a decrease in strength of the ground improvement body, and a cement-based solidification material that reduces dust when mixed with the ground even after storage, and can suppress a decrease in strength of the ground improvement body. The reason why such effects are manifested is not necessarily clear, but is presumed to be as follows. Sugar alcohol, which is component (a), has a high moisturizing effect as used in cosmetics, etc., so when it is added to a cement-based solidification material as a dust-reducing agent containing components (a) and (b), it is possible to inhibit the hydration reaction of the water contained in the dust-reducing agent and cement, just like sugars, and the dust-reducing effect can be sustained. Furthermore, since the sugar alcohol of component (a) has a smaller effect of delaying the hydration reaction of cement compared to sugars and oxycarboxylic acids, it is presumed that it was able to inhibit the decrease in strength of the ground improvement body when the cement-based solidification material is mixed into the ground. Furthermore, when a compound having an alkylene oxide chain, component (b1) described later, is used as component (b), these effects are synergistically improved in storage stability due to the water retention effect (effect of turning free water into hydrated water) of component (b1), and the performance of reducing dust when mixing with the ground even after storage of the cement-based solidification material is further improved, as well as inhibiting the decrease in strength of the ground improvement body.
[0013] [Dust reducing agent for cement-based systems] The dust-reducing agent for cement-based systems of the present invention contains a sugar alcohol as component (a). Examples of the sugar alcohol of component (a) include one or more selected from erythritol, xylitol, sorbitol, maltitol, reduced starch syrup, lactitol, isomaltitol, maltotriitol, isomaltotriitol, panitol, isomaltotetritoitol, arabitol, ribitol and mannitol. From the viewpoint of the dust reduction effect due to the moisturizing effect and the strength expression of the ground improvement body, one or more selected from erythritol, xylitol, sorbitol, maltitol and reduced starch syrup are preferred, one or more selected from sorbitol, maltitol and reduced starch syrup are more preferred, and sorbitol is even more preferred.
[0014] In the dust-reducing agent for cement-based systems of the present invention, the content of component (a) is preferably 0.5 mass% or more, more preferably 1 mass% or more, and even more preferably 2 mass% or more, from the viewpoint of storage stability and dust-reducing effect due to its moisturizing effect, and from the viewpoint of strength expression of the ground improvement body, it is preferably 40 mass% or less, more preferably 30 mass% or less, even more preferably 26 mass% or less, and even more preferably 20 mass% or less.
[0015] The dust-reducing agent for cement-based systems of the present invention contains an alcohol-based compound (excluding component (a)) as component (b). Examples of component (b) include one or more selected from an ethylene oxide adduct of methanol, polyethylene glycol, glycerin, diethylene glycol, polyoxyethylene alkyl ether, polyoxyethyleneoxyalkylene alkyl ether, and a block copolymer having a polyoxyethylene portion and a polyoxypropylene portion.
[0016] From the viewpoints of storage stability due to the water retention effect and strength development of the ground improvement body, it is preferable that the component (b) contains a compound represented by the following general formula (b1) as the component (b1). R 1 O-(C 2 H 4 O) n -H (b1) [R 1is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is C 2 H 4 The average number of moles of O added is 3 to 20.
[0017] In general formula (b1), R 1 From the viewpoint of the strength development of the ground improvement body, is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. From the viewpoint of storage stability due to the water retention effect, n is preferably 5 or more, more preferably 8 or more, and from the viewpoint of the solidification point, n is preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less.
[0018] From the viewpoint of improving uniformity by reducing the viscosity of the dust-reducing agent and improving the dust-reducing effect, it is preferable that the (b) component contains the above-mentioned (b1) component and, as the (b2) component, one or more compounds selected from glycerin and diethylene glycol.
[0019] In the dust-reducing agent for cement-based systems of the present invention, the content of component (b) is preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, still more preferably 30 mass% or more, and even more preferably 35 mass% or more, from the viewpoints of storage stability due to the water retention effect and dust-reducing effect, and is preferably 80 mass% or less, more preferably 60 mass% or less, and even more preferably 50 mass% or less, from the viewpoints of improving uniformity due to reduction in viscosity of the dust-reducing agent and the dust-reducing effect.
[0020] When the cement-based dust-reducing agent of the present invention contains the component (b1) as the component (b), the content of the component (b1) is, from the viewpoints of storage stability due to the water retention effect and dust-reducing effect, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, still more preferably 30 mass% or more, and even more preferably 35 mass% or more, and from the viewpoints of improving uniformity due to reduction in viscosity of the dust-reducing agent and the dust-reducing effect, preferably 80 mass% or less, more preferably 60 mass% or less, and even more preferably 50 mass% or less.
[0021] When the cement-based dust-reducing agent of the present invention contains the component (b2) as the component (b), the content of the component (b2) is preferably 5 mass% or more, more preferably 10 mass% or more, and even more preferably 20 mass% or more, from the viewpoints of improving uniformity by reducing the viscosity of the dust-reducing agent and the dust-reducing effect, and is preferably 50 mass% or less, more preferably 45 mass% or less, and even more preferably 40 mass% or less, from the viewpoints of storage stability and the dust-reducing effect.
[0022] In the cement-based dust-reducing agent of the present invention, the total content of components (a) and (b) is, from the viewpoints of inhibiting solidification of the cement-based solidification material and reducing dust, preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and even more preferably 40% by mass or more, and from the viewpoints of the dust-reducing effect, the strength expression of the ground improvement body, and the dust-reducing effect, it is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 65% by mass or less, and even more preferably 60% by mass or less.
[0023] In the cement-based dust-reducing agent of the present invention, the mass ratio (a) / (b) of the content of component (a) to the content of component (b) is, from the viewpoints of storage stability and dust-reducing effect, preferably 1 / 99 or more, more preferably 2 / 98 or more, even more preferably 5 / 95 or more, still more preferably 10 / 90 or more, still more preferably 20 / 80 or more, still more preferably 25 / 75 or more, and still more preferably 30 / 70 or more, and from the viewpoint of strength expression of the ground improvement body, preferably 60 / 40 or less, more preferably 50 / 50 or less, still more preferably 40 / 60 or less, and still more preferably 35 / 65 or less.
[0024] In the case where the cement-based dust-reducing agent of the present invention contains the component (b1) as the component (b), the mass ratio (a) / (b1) of the content of the component (a) to the content of the component (b1) is, from the viewpoints of storage stability and dust-reducing effect, preferably 1 / 99 or more, more preferably 2 / 98 or more, even more preferably 5 / 95 or more, still more preferably 10 / 90 or more, still more preferably 20 / 80 or more, still more preferably 25 / 75 or more, and still more preferably 30 / 70 or more, and from the viewpoint of the strength expression of the ground improvement body, preferably 60 / 40 or less, more preferably 50 / 50 or less, and even more preferably 40 / 60 or less.
[0025] In the cement-based dust-reducing agent of the present invention, when the component (b) contains the components (b1) and (b2), the mass ratio of the content of the component (b1) to the content of the component (b2), (b1) / (b2), is preferably 20 / 80 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, from the viewpoint of the strength expression of the ground improvement body, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, even more preferably 80 / 20 or less, and even more preferably 70 / 30 or less, from the viewpoint of the dust-reducing effect.
[0026] The dust-reducing agent for cement systems of the present invention contains water, that is, the dust-reducing agent for cement systems of the present invention is a liquid, preferably an aqueous solution. In the cement-based dust reducing agent of the present invention, the water content is preferably 15 mass% or more, more preferably 20 mass% or more, and even more preferably 25 mass% or more from the viewpoints of safety (non-hazardous material) and deterioration of uniformity due to solution viscosity, and from the viewpoint of inhibiting solidification of the cement-based solidification material, it is preferably 80 mass% or less, more preferably 70 mass% or less, and even more preferably 65 mass% or less.
[0027] The viscosity of the cement-based dust-reducing agent of the present invention at 25°C is preferably 150 mPa·s or less, more preferably 100 mPa·s or less, from the viewpoint of ease of spraying. With a viscosity of 150 mPa·s or less, there is a tendency for spraying to be easier when mixed with cement. This viscosity was measured at 24 to 26°C using a VISCOMETER (BM type) manufactured by Tokyo Keiki Co., Ltd.
[0028] The dust-reducing agent for cement-based systems of the present invention is suitable for use in cement-based applications. In the present invention, the dust-reducing agent for cement-based systems refers to a dust-reducing agent suitable for use in powdery compositions containing cement, such as cement-based solidification materials, cement-lime composite solidification materials, ordinary Portland cement, high-early-strength Portland cement, blast-furnace cement, and fly ash cement. In particular, the dust-reducing agent for cement-based systems of the present invention can be suitably used for cement-based solidification materials.
[0029] [Cement-based solidification material] The present invention provides a cement-based solidification material containing the cement-based dust-reducing agent of the present invention and cement. That is, the present invention provides a cement-based solidification material containing component (a), component (b), water, and cement. The cement-based solidification material obtained by the present invention is a dust-inhibiting cement-based solidification material. The components (a) and (b) are the same as those described in the dust-reducing agent for cement-based systems of the present invention. The cement-based solidification material of the present invention can be appropriately applied with the embodiments described in the dust-reducing agent for cement-based systems of the present invention.
[0030] The cement used in the present invention mainly reacts with the moisture in the soil when mixed with the soil, solidifying and contributing to strengthening the ground. In the present invention, for example, Portland cement, normal Portland cement, and high-early-strength Portland cement can be preferably used as the cement source. In addition, commercially available solidifying materials containing cement can be used. As other components, blast furnace slag and gypsum can be preferably used. In addition, to the cement, powders having pozzolanic action and / or latent hydraulic properties, such as fly ash and silica fume, and stone powder (calcium carbonate powder), etc. may be added as long as the effects of the present invention are not impaired.
[0031] In the cement-based solidification material of the present invention, the content of the cement-based dust-reducing agent of the present invention is preferably 1 mass% or more, more preferably 2 mass% or more, even more preferably 3 mass% or more, and even more preferably 3.5 mass% or more, from the viewpoint of achieving both dust reduction and strength of the ground improvement body, and from the viewpoint of dust reduction, it is preferably 10 mass% or less, more preferably 8 mass% or less, and even more preferably 6 mass% or less.
[0032] In the cement-based solidification material of the present invention, the content of component (a) is, from the viewpoint of dust reduction effect, preferably 0.03 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, still more preferably 0.3 mass% or more, still more preferably 0.5 mass% or more, still more preferably 0.7 mass% or more, and from the viewpoint of strength expression of the ground improvement body, preferably 5.0 mass% or less, more preferably 3.0 mass% or less, even more preferably 2.0 mass% or less, still more preferably 1.5 mass% or less, and still more preferably 1.3 mass% or less.
[0033] In the cement-based solidification material of the present invention, the content of component (b) is preferably 0.5 mass% or more, more preferably 0.8 mass% or more, and even more preferably 1.0 mass% or more, from the viewpoint of the dust reduction effect, and is preferably 4 mass% or less, more preferably 3.0 mass% or less, even more preferably 2.5 mass% or less, still more preferably 2.0 mass% or less, still more preferably 1.7 mass% or less, still more preferably 1.6 mass% or less, and even more preferably 1.5 mass% or less, from the viewpoint of the strength expression of the ground improvement body.
[0034] When the cement-based solidification material of the present invention contains the (b1) component as the (b) component, the content of the (b1) component is preferably 0.5 mass% or more, more preferably 0.8 mass% or more, and even more preferably 1.0 mass% or more from the viewpoint of the dust reduction effect, and is preferably 4 mass% or less, more preferably 3.0 mass% or less, even more preferably 2.5 mass% or less, still more preferably 2.0 mass% or less, still more preferably 1.7 mass% or less, still more preferably 1.6 mass% or less, and even more preferably 1.5 mass% or less from the viewpoint of the strength expression of the ground improvement body.
[0035] When the cement-based solidification material of the present invention contains the component (b2) as the component (b), the content of the component (b2) is preferably 0.2 mass% or more from the viewpoint of the dust reduction effect, more preferably 0.3 mass% or more, even more preferably 0.4 mass% or more, and even more preferably 0.6 mass% or more, and from the viewpoint of the strength expression of the ground improvement body, it is preferably 2.5 mass% or less, more preferably 2.0 mass% or less, and even more preferably 1.6 mass% or less.
[0036] In the cement-based solidification material of the present invention, the water content is preferably 0.5 mass% or more, more preferably 0.8 mass% or more, even more preferably 1.0 mass% or more, still more preferably 1.3 mass% or more, still more preferably 1.5 mass% or more, and preferably 3.5 mass% or less, more preferably 3.2 mass% or less, still more preferably 2.8 mass% or less, and still more preferably 2.5 mass% or less, from the viewpoint of achieving both a dust reduction effect and the strength expression of the ground improvement body.
[0037] In the cement-based solidification material of the present invention, the cement content is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more from the viewpoint of strength development, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less from the viewpoint of elution of hexavalent chromium. In the present invention, the amount of cement does not include the amount of powder having pozzolanic action and / or latent hydraulic property, such as blast furnace slag, gypsum, fly ash, and silica fume.
[0038] In the cement-based solidification material of the present invention, the mass ratio (a) / (b) of the content of the component (a) to the content of the component (b), the mass ratio (a) / (b1) of the content of the component (a) to the content of the component (b1), and the mass ratio (b1) / (b2) of the content of the component (b1) to the content of the component (b2) can be appropriately applied by replacing the mass ratios of each component in the dust-reducing agent of the present invention described in the dust-reducing agent of the present invention with the mass ratios of each component in the cement-based solidification material of the present invention.
[0039] The cement-based solidification material of the present invention is preferably a powder. From the viewpoint of suppressing dust generation, the cement-based solidification material of the present invention preferably has a sieve passing rate of 40 mass% or less in a sieve test with a sieve opening of 500 μm (for example, a vibrating type sieve manufactured by AS ONE Corporation for 30 seconds).
[0040] [Method of manufacturing cement-based solidification material] The present invention provides a method for producing a cement-based solidification material, which comprises mixing the dust-reducing agent of the present invention with cement. That is, the present invention provides a method for producing a cement-based solidification material, which comprises mixing a dust-reducing agent containing component (a), component (b), and water with cement. The cement-based solidification material obtained by the present invention is a dust-generation inhibitor type cement-based solidification material. The components (a) and (b) are the same as those described in the dust-reducing agent of the present invention. In the manufacturing method of the cement-based solidification material of the present invention, the mixing amount of the dust-reducing agent of the present invention, the mixing amount of component (a), the mixing amount of component (b), the mixing amount of component (b1), the mixing amount of component (b2), the mixing amount of water, and the mixing amount of cement can be appropriately applied by replacing the mixing amount with the content of the dust-reducing agent of the present invention and the content of each component in the cement-based solidification material described in the cement-based solidification material of the present invention. In the manufacturing method of the cement-based solidification material of the present invention, the mass ratio (a) / (b) between the mixed amount of component (a) and the mixed amount of component (b), the mass ratio (a) / (b1) between the mixed amount of component (a) and the mixed amount of component (b1), and the mass ratio (b1) / (b2) between the mixed amount of component (b1) and the mixed amount of component (b2) can be appropriately applied by replacing the mass ratios of the contents of each component in the dust-reducing agent of the present invention described in the dust-reducing agent of the present invention with the mass ratios of the mixed amounts of each component in the manufacturing method of the cement-based solidification material of the present invention. The method for producing the cement-based solidification material of the present invention can be appropriately applied to the aspects described for the dust-reducing agent of the present invention and the cement-based solidification material of the present invention.
[0041] In the manufacturing method of the cement-based solidification material of the present invention, methods for uniformly adding and mixing a liquid, preferably an aqueous solution, of the dust-reducing agent of the present invention to cement include a method of spraying the dust-reducing agent of the present invention onto cement being stirred in a mixer, a method of dripping the dust-reducing agent of the present invention onto cement being stirred in a mixer, and a method of mixing the dust-reducing agent of the present invention with another powder in advance and then uniformly mixing the powder with cement.
[0042] In order to suppress dust generation due to scattering of the cement-based solidification material, it is important that the liquid of the dust-reducing agent of the present invention "wets" and "spreads" on the cement powder surface. The wettability of the powder surface is governed by the surface tension of the liquid, and the wettability and spreadability on the powder surface is governed by the viscosity of the liquid. From the viewpoint of dust generation suppression effect, it is preferable that the liquid of the dust-reducing agent of the present invention has both the functions of "wetting" and "spreading". If only water is used as this liquid, the cement and water will react over time and it will no longer function as a solidification material.
[0043] Use of the dust-reducing agent of the present invention containing components (a), (b), and water can reduce the viscosity of a mixture of components (a) and (b) compared to use without adding water, making it possible to uniformly add and mix the agent into cement by spraying, etc., and significantly improving the dust generation suppression effect. Therefore, the water content in the dust-reducing agent of the present invention is important, and the viscosity of the dust-reducing agent of the present invention is important from the viewpoint of "uniform addition and mixing" by spraying.
[0044] [Ground improvement method] The present invention provides a ground improvement method in which the cement-based solidification material of the present invention is mixed with soil. The ground improvement method of the present invention can appropriately apply the aspects described in the dust-reducing agent of the present invention, and the cement-based solidification material and its manufacturing method of the present invention.
[0045] The ground improvement method of the present invention is effective even when the soil is clayey, that is, soil containing clay. The soil may be clayey soil. Furthermore, the ground improvement method of the present invention can also be used for improving soil containing seawater or marine clayey soil.
[0046] In the present invention, the cement-based solidification material of the present invention is applied in powder form to 1 m of soil. 3 The amount of the mixture is 50 kg or more, preferably 80 kg or more, more preferably 100 kg or more, and 400 kg or less, preferably 300 kg or less, more preferably 250 kg or less per unit time.
[0047] The ground improvement method of the present invention can be applied to surface layer improvement methods and the like.
[0048] In the ground improvement method of the present invention, the cement-based solidification material of the present invention is mixed in the form of powder with the soil. For example, after the soil is treated by spreading or raking, a predetermined amount of the powdered cement-based solidification material of the present invention is spread on the soil, and the soil and the cement-based solidification material are mixed by a rolling compaction method using a mixing machine such as a stabilizer. Also, it can be performed by a so-called in-situ mixing method in which external soil is brought into the ground to be improved and spread evenly, and then the powdered cement-based solidification material of the present invention is spread on the soil. Also, it can be performed by a so-called pre-mixing method in which the soil and the powdered cement-based solidification material of the present invention are mixed in advance at a borrow pit or the like, and then the mixture is brought into the ground to be improved. In either method, the mixing of the soil and the powdered cement-based solidification material of the present invention can be performed by a known method.
[0049] [Method for reducing dust in powder composition] The present invention provides a method for reducing dust in a powdery composition containing cement, by mixing a dust-reducing agent for cement-based systems, which contains component (a), component (b), and water, with the powdery composition. The dust-reducing agent for cement systems is the same as the dust-reducing agent for cement systems of the present invention. The components (a) and (b) are the same as those described in the dust-reducing agent for cement systems of the present invention. The embodiments described in the dust-reducing agent for cement systems of the present invention can be appropriately applied.
[0050] Examples of powdery compositions containing cement include those containing cement such as cement-lime composite solidifying materials, ordinary Portland cement, high-early-strength Portland cement, blast-furnace cement, and fly ash cement.
[0051] In the method for reducing dust in the powdery composition of the present invention, the mixing amount of the dust-reducing agent of the present invention, the mixing amount of component (a), the mixing amount of component (b), the mixing amount of component (b1), the mixing amount of component (b2), the mixing amount of water, and the mixing amount of cement can be appropriately applied by replacing the mixing amounts with the contents of the dust-reducing agent of the present invention and the contents of each component in the cement-based solidification material described in the cement-based solidification material of the present invention. In the method for reducing dust from the powdery composition of the present invention, the mass ratio (a) / (b) between the mixed amount of component (a) and the mixed amount of component (b), the mass ratio (a) / (b1) between the mixed amount of component (a) and the mixed amount of component (b1), and the mass ratio (b1) / (b2) between the mixed amount of component (b1) and the mixed amount of component (b2) can be appropriately applied by replacing the mass ratios of the contents of each component in the dust-reducing agent of the present invention described in the dust-reducing agent of the present invention with the mass ratios of the mixed amounts of each component in the method for reducing dust from the powdery composition of the present invention. The method for reducing dust of the powdery composition of the present invention can be appropriately applied to the embodiments described in the dust-reducing agent of the present invention, the cement-based solidification material of the present invention and the production method thereof. EXAMPLES
[0052] The components in the table are as follows: <Component (a)> Sorbitol: Cargill "SORBIDEX71100" Erythritol: "Erythritol B" manufactured by Mitsubishi Chemical Corporation Xylitol: "Food Additive Xylitol" manufactured by Mitsubishi Corporation Life Sciences Co., Ltd. Maltitol: "Amalti Syrup" manufactured by Mitsubishi Corporation Life Sciences Co., Ltd. SE600: Highly sugared reduced starch syrup containing 40-50% monosaccharide alcohol, 40-50% disaccharide alcohol, 8-13% trisaccharide alcohol, 1-5% tetrasaccharide alcohol, and 1-5% or more pentasaccharide alcohol, manufactured by Bussan Food Science Co., Ltd. SE57: Medium sugar content reduced starch syrup containing 3-10% monosaccharide alcohol, 40-50% disaccharide alcohol, 15-25% trisaccharide alcohol, 1-5% tetrasaccharide alcohol, and 10-38% or more pentasaccharide alcohol, manufactured by Bussan Food Science Co., Ltd.
[0053] <Component (a') (comparison component for component (a))> Glucose: "D-glucose" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Maltose: "Maltose monohydrate" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Fracto M75: A mixture of fructose and glucose, manufactured by Japan Corn Starch Co., Ltd. Fract M75-00-20: A mixture of fructose and glucose, manufactured by Japan Corn Starch Co., Ltd. · Corso Syrup H75: Main component is maltose, manufactured by Japan Corn Starch Co., Ltd. Sodium gluconate: "Sodium gluconate" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Sodium citrate: "Trisodium citrate dihydrate" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.
[0054] <(b) Component> MEPEG (9): Ethylene oxide adduct of methanol, average number of moles of ethylene oxide added: 9, (b1) component, manufactured by Kao Corporation Glycerin: (b2) ingredient, APICID G995U USP manufactured by Apical Diethylene glycol: component (b2), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.
[0055] Preparation of cement-based dust reducing agent Component (a) or (a'), component (b), and tap water (Wakayama City tap water, specific gravity 1.00) were added in the amounts (mass%) shown in Tables 1 and 2 to prepare a cement-based dust-reducing agent.
[0056] Storage stability evaluation 100 g of each of the prepared cement-based dust-reducing agents in Tables 1 and 2 was placed in a 100 mL screw tube, capped and stored in a sealed state at 25°C for one day. After storage, the appearance of each cement-based dust-reducing agent was visually observed and judged according to the following criteria. The results are shown in Tables 1 and 2. It is preferable that the appearance is transparent. Transparency: The appearance is transparent and good. Yellowing: The appearance is yellowed. Cloudy: The appearance is cloudy. Layered / cloudy: The appearance is layered and cloudy.
[0057] Method for preparing dust-suppressing cement-based solidification material Each cement-based dust reducing agent in Tables 1 and 2 was mixed with the cement-based solidification material Tuffloc 3E (manufactured by Sumitomo Osaka Cement Co., Ltd., a general-purpose cement-based solidification material containing cement, blast furnace slag, and gypsum) to prepare a dust-suppressing cement-based solidification material. Specifically, each cement-based dust-reducing agent in Tables 1 and 2 and 800 g of Tuffloc 3E were added to a Hobart-type mixer described in JIS R 5201 so that the amount (mass%) of cement-based dust-reducing agent added in the total amount of dust-reducing cement-based solidification material was the value shown in Tables 1 and 2, and the mixture was mixed at 62 rpm for 3.5 minutes, scraped off, and further mixed at 62 rpm for 3.5 minutes to prepare each dust-reducing cement-based solidification material. The obtained dust-suppressing cement-based solidification materials were all transferred into sealed nylon bags and left to stand in a temperature-constant humidity room at a temperature of 20°C and a humidity of 60%. After 7 days of standing, 100 g of each dust-suppressing cement-based solidification material was used for the evaluation of (5) strength development, which will be described later, and after 30 days of standing, each dust-suppressing cement-based solidification material was used for the evaluation of (4) dust reduction, which will be described later.
[0058] (4) Evaluation of dust reduction After leaving each dust-inhibiting cementitious solidification material for 30 days in a constant temperature and humidity room at a temperature of 20°C and a humidity of 60%, a sieve test (sieve opening 500μm, AS ONE Vibrating Type for 30 seconds) was conducted to measure the sieve passing rate (amount passing relative to the total amount of dust-inhibiting cementitious solidification material). The results are shown in Tables 1 and 2. The smaller the sieve passing rate, the more dust can be reduced when the dust-inhibiting cementitious solidification material is mixed into the ground, which is preferable.
[0059] Evaluation of strength development After being left to stand for 7 days in a temperature and humidity chamber at 20°C and 60% humidity, 100g of each dust-reducing cement-based solidification material was weighed into a 300ml plastic cup, 45g of water was added, and the mixture was stirred for 30 seconds with a household hand mixer (low speed), and the entire amount was transferred to a 100g plastic cup to prepare a paste. Two of these pastes were prepared and cured for 3 or 7 days in a temperature and humidity chamber at 20°C and 60% humidity to harden the paste. The strength of the hardened paste after curing for 3 or 7 days was measured using a Proctor penetration resistance tester (penetration needle 12.5mm). 2The penetration resistance was measured using a 100-mm2 test piece. The results are shown in Tables 1 and 2. In the tables, the penetration resistance is indicated as "80<" when the penetration resistance is 80 N / mm2, which is the upper limit of the measurement limit. 2 The higher the penetration resistance value, the more the strength reduction of the ground improvement body can be suppressed when the dust-suppressing cement-based solidification material is mixed into the ground.
[0060] [Table 1]
[0061] [Table 2]
Claims
1. A dust reducing agent for cement-based materials, comprising (a) a sugar alcohol (hereinafter referred to as component (a)), (b) an alcohol-based compound (excluding component (a)) (hereinafter referred to as component (b)), and water.
2. (a) The cement-based dust reducing agent according to claim 1, wherein the component is one or more selected from erythritol, xylitol, sorbitol, maltitol, and reduced starch syrup.
3. The cement-based dust reducer according to claim 1 or 2, wherein component (b) comprises a compound represented by the following general formula (b1) as component (b1). R １ O- (C) ２ H ４ O) ｎ -H (｡1) [R １ n is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is C ２ H ４ This is the average number of moles of O added, and is between 3 and 20.
4. The cement-based dust reducing agent according to claim 3, wherein component (b) further comprises one or more compounds selected from glycerin and diethylene glycol as component (b2).
5. The cement-based dust reducing agent according to claim 1 or 2, wherein the mass ratio (a) / (b) of the content of component (a) to the content of component (b) is 1 / 99 or more and 60 / 40 or less.
6. A dust reducing agent for cement-based materials according to claim 1 or 2, wherein the water content is 15% by mass or more and 80% by mass or less.
7. A cement-based dust reducing agent according to claim 1 or 2, and a cement-based solidifying agent containing cement.
8. The cement-based solidifying material according to claim 7, wherein the content of the cement-based dust reducing agent is 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of cement.
9. A method for reducing dust in a powdered composition containing cement, comprising mixing a cement-based dust reducing agent containing (a) a sugar alcohol (hereinafter referred to as component (a)), (b) an alcohol-based compound (excluding component (a)), and water, with the powdered composition containing cement.