JP4836005B2 - Method for producing dust-suppressing hydraulic material - Google Patents

Description

  The present invention relates to a method for producing a dust-suppressing hydraulic material that is suitable for solidification treatment of soft ground or the like, or for use in a spraying method.

  Conventionally, cement-based solidified materials and lime-based solidified materials have been used for soil improvement of soft ground. In particular, in the improvement of the surface layer portion, construction is carried out by a method in which cement-based solidified material or lime-based solidified material is directly added and mixed. However, the addition and mixing of the cement-based solidified material and the lime-based solidified material to the surface layer portion may generate dust during the work and may deteriorate the surrounding environment and the work environment. This is a similar problem when cement is used in spraying methods such as fireproof coating. Therefore, the following countermeasures are considered.

  For example, Patent Document 1 discloses a method of suppressing generation of dust in a construction process in which a cement composition is moistened with an organic liquid and water is added. Examples of the organic liquid include ethylene glycol, diethylene glycol, and polyethylene glycol. Moreover, in patent document 2, the method of using diethylene glycol with respect to cement as a dust generation inhibitor is disclosed.

  Further, Patent Document 3 discloses a non-dust solidifying material for ground improvement in which an aqueous solution of an alcohol-based compound having a concentration of 5 to 70% by weight is uniformly added to and mixed with 1 to 10% by weight of the cement-based solidified material. ing. Furthermore, in Patent Document 4, the raw material consists of a combination of at least one glycol, glycerin or ether and liquid paraffin, and the mixing ratio is 1: 3 to 3: 1. A solidifying material is disclosed. Patent Document 5 discloses that the effect of preventing dust generation can be obtained by spraying polyalkylene glycol onto cement powder in the form of a mist having a particle size of the order of μm.

JP 57-7852 A Japanese Patent No. 2622920 Japanese Patent No. 3090301 Japanese Patent No. 2979916 Japanese Patent No. 2980752

The following problems remain in the conventional technology.
In other words, the technique described in Patent Document 1 has a problem in that there are changes over time in the performance and quality of dust generation suppression, and it is difficult to apply to actual materials. Moreover, in the technique described in Patent Document 2, the amount of the actual dust generation inhibitor added is large, the material becomes expensive, and there is a concern that the contained organic matter may adversely affect the environment. In the technique described in Patent Document 3, the material is inexpensive, but since water is included, there is a concern that the effect cannot be expected for a long period of time and the cement is solidified by reaction with water. Furthermore, the technique described in Patent Document 4 is composed of a combination of two or more materials, and there is a problem that the manufacturing method becomes complicated. Moreover, since the technique described in Patent Document 5 requires a special device for spraying in a mist form, there is a problem that the cost of equipment is expensive.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a simple method for producing an inexpensive dust-suppressing hydraulic material.

  The present invention employs the following configuration in order to solve the above problems. That is, the method for producing a dust-suppressing hydraulic material of the present invention includes an addition step of adding and mixing at least one of an aliphatic polyhydric alcohol or an ether compound as a dust-suppressing agent to the hydraulic material. In the addition step, the number of times of addition is divided into two times and the addition ratio of the first time and the second time is set to 2: 8 to 8: 2, and after mixing for the first time, 24 minutes or more. The mixture is allowed to stand for a period of time and mixed for the second time, and the addition is performed in the range of 0.5% to 8% by weight with respect to the hydraulic material as a whole.

  In this method of producing a dust-suppressing hydraulic material, when adding and mixing at least one kind of aliphatic polyhydric alcohol or ether compound, the number of times of addition is divided into two and mixed so far. It is possible to produce a dust-suppressing solidified material even with a material that has a low dust-suppressing effect, and the amount of aliphatic polyhydric alcohol or ether compound can be reduced, leading to a reduction in environmental burden and low cost. There is merit to become. Further, since the operation only needs to add and mix the aliphatic polyhydric alcohol or the ether compound into the hydraulic material in two portions, the operation is simple and inexpensive.

The reason why the addition ratio between the first time and the second time is set in the range of 2: 8 to 8: 2 is that the amount to be added at one time increases outside this range. This is because the generation of dust cannot be sufficiently suppressed.
Moreover, the reason for making it still stand for 5 minutes or more from the 1st addition to the 2nd addition is because a big inhibitory effect cannot be anticipated by standing for less than 5 minutes. The reason for setting the time from the first addition to the second addition within 24 hours is that if the time until the second addition is too long, the production will be hindered, which is not practical.

  Furthermore, the addition amount of the aliphatic polyhydric alcohol or the ether compound is added in the range of 0.5% to 8% by weight, preferably in the range of 1 to 6% by weight with respect to the hydraulic material. Here, the reason why the addition amount is in the range of 0.5% to 8% weight is that if it is less than 0.5% weight, the dust generation is increased, and if it exceeds 8% weight, the mixed aliphatic polyhydric alcohol is used. Alternatively, the ether compound not only aggregates the powders but also links the aliphatic polyhydric alcohol or the ether compound itself to lose fluidity as a powder of the hydraulic material.

  In addition, the method for producing a dust-suppressing hydraulic material according to the present invention further comprises a stationary curing within 1 to 30 days in a state where the dust-suppressing hydraulic material obtained in the addition step is packaged. It has the process to make it feature. That is, in this method for producing a dust-suppressing hydraulic material, after the second mixing, it is further allowed to stand for one day or more in a bag-packed state, so that aliphatic polyhydric alcohol or ether compound and hydraulic The material is mixed uniformly and penetrates uniformly, and the effect of suppressing dust generation can be exhibited more.

  Further, in the method for producing a dust-suppressing hydraulic material of the present invention, the aliphatic polyhydric alcohol or the ether compound is selected from ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, or liquid paraffin. It is one or more types. That is, in the method for producing a dust-suppressing hydraulic material, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, or liquid paraffin is used alone or 2 of these as the aliphatic polyhydric alcohol or ether compound. Since these materials are used in combination, the vapor pressure of these materials is low and it is difficult to evaporate.Therefore, the dust generation suppression effect can be maintained for a long period of time, and the solidification reaction of the hydraulic material is not greatly affected. Since the property is also good, it is preferable.

  In addition, the method for producing a dust-suppressing hydraulic material according to the present invention includes at least one kind of Portland cement, lime, mixed cement, solidifying material for soil improvement, or special cement as the hydraulic material to be used. Features.

The present invention has the following effects.
That is, according to the method for producing a dust generation suppressing hydraulic material according to the present invention, when adding and mixing at least one kind of aliphatic polyhydric alcohol or ether compound, the number of additions is divided into two. Since they are mixed, a high dust generation suppressing effect can be obtained by a simple method, and the additive material can be reduced, and the cost can be reduced. Therefore, it is possible to obtain a dust generation-suppressing hydraulic material suitable for use in solidification processing of the ground or the like, or for use in a spraying method.

  Hereinafter, an embodiment of a method for producing a dust generation suppressing hydraulic material according to the present invention will be described with reference to FIG.

  The method for producing a dust-suppressing hydraulic material of the present embodiment includes an addition step of adding and mixing at least one of an aliphatic polyhydric alcohol or an ether compound as a dust-suppressing agent to the hydraulic material. As shown in FIG. 1, this addition step divides the number of additions into two steps, the first addition step (step S1), and the static curing step after the first addition (step S2). ), A step of performing the second addition after the curing (step S3), a step of bagging the dust-suppressing hydraulic material obtained in the addition step (step S4), and the bagging. And a step (step S5) of standing and curing within 1 day to 30 days in the state.

As described above, in the addition step, the number of times of addition is divided into two and mixed, and the addition ratio between the first time (step S1) and the second time (step S3) is set to 2: 8 to 8: 2. In addition, the addition ratio of the first time and the second time is preferably 4: 6 to 6: 4.
Moreover, in the said stationary curing process (step S2), stationary curing is performed for 5 minutes or more and less than 24 hours after the 1st time (step S1) addition mixing.
Furthermore, in the said addition process, the said addition is performed in 0.5 to 8% of weight range with respect to a hydraulic material as a whole. In addition, Preferably it adds in 1 to 6% of weight range.

  The reason why the addition ratio of the first time and the second time is in the range of 2: 8 to 8: 2 is as follows. The reason for static curing for 5 minutes to 24 hours from the first addition to the second addition and the addition amount is 0. The reason for the range of 5% to 8% by weight is as described above.

Moreover, as a device used for the addition and mixing, a batch-type device can be used. The mixer system may be any one as long as it has a function of mixing performance such as a single-shaft type, a twin-screw type, a pro-shear mixer, a V-type mixer, a horizontal rotation (pan type) type, or the like.
In addition, the form of the bag and the bagging method in the bagging process (step S4) are not particularly limited, but the bag can be packed in a general flexible container, cement bag, sandbag bag, plastic bag, or the like.

As the aliphatic polyhydric alcohol or the ether compound, one or more selected from ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin or liquid paraffin are employed.
Further, as the hydraulic material to be used, a material containing at least one kind of Portland cement, lime, mixed cement, soil improvement solidifying material or special cement is employed.

  Examples of the Portland cement include normal, early strength, super early strength, moderate heat, and low heat. The lime is not limited to slaked lime and quick lime, but also lime-based solidified material in which pozzolana or gypsum is mixed with lime. Moreover, as mixed cement, there exist types, such as a blast furnace cement, a fly ash cement, a silica cement, and these are all contained. Moreover, as the solidification material for soil improvement, a cement type solidification material, a lime type solidification material, a gypsum type solidification material, a slag type solidification material, a neutral solidification material, etc. are contained.

  In addition, as special cements, there are expansive cements based on Portland cement, two-component or three-component low heat-generating cements, etc. , Cement-based solidifying material, ultrafine-particle cement, high belite-based cement, and the like. Furthermore, as a special cement having a component different from Portland cement, there are ultrafast cement, alumina cement, eco cement and the like.

  As described above, in the present embodiment, when adding and mixing at least one kind of aliphatic polyhydric alcohol or ether-based compound, the number of times of addition is divided into two and mixed, so far the dust generation suppressing effect has been achieved. It is possible to produce a solidification material that suppresses dusting even with low materials, and it is possible to reduce the amount of aliphatic polyhydric alcohol or ether-based compound added, leading to a reduction in environmental impact and cost reduction. . Further, since the operation only needs to add and mix the aliphatic polyhydric alcohol or the ether compound into the hydraulic material in two portions, the operation is simple and inexpensive.

  Conventionally, as a general method for adding an aliphatic polyhydric alcohol or an ether compound, there is a dropping method. In this method, an aliphatic polyhydric alcohol or an ether compound is used as a hydraulic material. It will disperse | distribute unevenly with respect to material, and generation | occurrence | production of dust cannot fully be suppressed. On the other hand, in the present invention, since the number of times of addition is divided into two and mixed, the aliphatic polyhydric alcohol or ether compound is uniformly dispersed in the hydraulic material, and a high dust generation suppressing effect can be obtained. it can.

  In addition, after mixing for the second time, the polyhydric alcohol or ether-based compound and the hydraulic material are uniformly mixed and permeated uniformly by allowing to stand for one day or more in a bagged state. The effect of suppressing dust generation can be exhibited more.

  Furthermore, as the aliphatic polyhydric alcohol or ether compound, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin or liquid paraffin is used alone, or two or more of them are used in combination. Therefore, it is preferable because the dust generation suppressing effect can be maintained for a long period of time, the solidification reaction of the hydraulic material is not greatly affected, and the mixing property with the hydraulic material is good.

Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.
The materials used in this example include normal Portland cement (made by Ube Mitsubishi Cement Co., Ltd., symbol N), quicklime (made by Ryoko Lime Industry Co., Ltd., symbol CaO), cement-based solidified material youth tabiler 10 ( (Registered trademark) (Ube Mitsubishi Cement Co., Ltd., symbol US10) was used. In addition, as a dust suppressant, ethylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent, symbol EG), diethylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent, symbol DEG), polyethylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent, symbol) PEG) and liquid paraffin (manufactured by Kanto Chemical Co., Inc., reagent, FP) were used.

The target soils are volcanic ash cohesive soil (Kami-Fukuoka City sampling, wet density 1.35 g / cm ³ , moisture content 114.2%, symbol VH), organic soil (Saitama City sampling, wet density 1.12 g / cm ³ , Moisture content 315.5%, symbol PT), sandy soil (Kawaguchi City extract, wet density 1.89 g / cm ³ , moisture content 34.5%, symbol S) was used.

  Add 5% of the dust generation inhibitor shown in Table 1 and Table 2 below in a weight ratio to the hydraulic material (addition amount is changed in some tests), and stir and mix in a mixer for 5 minutes. Thus, a hydraulic material was produced. In the second addition step, the first and second addition ratios and the time until the second addition were set to the ratios and times shown in Tables 1 and 2, and the mixture was stirred and mixed to produce a dust-suppressing hydraulic material. . The stirring and mixing time was 5 minutes for the first addition and twice for 2.5 minutes for the second addition, so that the total time was the same.

  For the measurement of the amount of dust, floating in a cylindrical container (80L plastic container) using a digital dust meter (P-5L2 model manufactured by Shibata Kagaku Co., Ltd.) applying the principle that the amount of light scattered by dust is proportional to the mass concentration. The amount of dust generation (relative concentration CPM [Count Per Minute]) was measured. At this time, 200 g of the sample is naturally dropped from the top of the cylindrical container, the lid is quickly covered, and measurement is performed up to 5 times (5 minutes) continuously. The geometrical average value obtained by subtracting the dark count before the sample was added from the measured value was used as the amount of dust falling from the sample.

  The measurement time of the dust generation amount was 1 day and 30 days after the dust generation suppression solidified material was sealed in a sealed state immediately after production and allowed to stand for curing. The measurement results are shown in Table 1. In addition, as a comparative example, the same measurement results are also shown in Table 1 for the case where the dust generation inhibitor was added by a method deviating from the manufacturing conditions in the examples of the present invention. The target good dust generation amount was 20 CPM (more preferably 10 CPM) or less.

Moreover, the uniaxial compression test was done by performing the solidification process using the soil and dust generation-suppressing hydraulic material described above. The uniaxial compression test method, by adding the dust suppression type hydraulic material of 300 kg / m ³ to the sample soil, and mixed well in a Hobart type soil mixer, a uniaxial compression test according to the Geotechnical Society criteria JGS 0821 A specimen was prepared. And the uniaxial compressive strength was measured based on Japanese Industrial Standard JIS A1216 at the age of 7 days. The measurement results are shown in Table 2. In this measurement as well, as a comparative example, the same measurement results are also shown in Table 2 for the case where the dusting inhibitor is added and mixed once.

As can be seen from Table 1, the amount of dust generation is reduced when the method of adding the dust generation inhibitor is changed from once to twice in the present invention. Moreover, in any dust generation inhibitor, the dust suppression effect by adding twice is recognized.
In addition, a dust generation inhibitory effect is not recognized when the addition ratio of the dust generation inhibitor of the 1st time and the 2nd time is not 2: 8-8: 2 like the comparative examples 8 and 9. In addition, if the standing time until the second addition is 5 minutes or more, the dust generation suppressing effect is recognized, but if it is less than 5 minutes as in Comparative Example 6, the dust generation suppressing effect is not recognized.

  Further, as in Comparative Example 7, when the addition rate is less than 0.5% by weight, the dust generation suppressing effect is not recognized. Moreover, even if it reduces the quantity of the dust generation inhibitor to add by adding twice like Example 12, the high dust generation suppression effect is acquired. In addition, after production, when static curing was carried out by bagging, the amount of dust generation was smaller when added twice than when added once.

  In addition, from Table 2, it was found that the strength of the solidified soil was not reduced by adding twice compared to adding once. Moreover, it turns out that the intensity | strength of a solidification process soil does not have a strength fall compared with 1 time addition irrespective of the kind of improvement object soil.

  The technical scope of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the present invention.

It is a flowchart which shows a manufacturing process in one Embodiment of the manufacturing method of the dust generation suppression hydraulic material which concerns on this invention.

Claims (4)

As a dust control agent to the hydraulic material, it has an addition step of adding and mixing at least one kind of aliphatic polyhydric alcohol or ether compound,
In the addition step, the number of times of addition is divided into two times, and the addition ratio of the first time and the second time is set to 2: 8 to 8: 2, and after mixing the first time, within 5 minutes to 24 hours Of the dust generation-suppressing hydraulic material, characterized in that the second mixing is carried out by static curing, and the addition is performed in the range of 0.5% to 8% by weight with respect to the hydraulic material as a whole. Production method. In the manufacturing method of the dust generation suppression type hydraulic material according to claim 1,
A dust generation suppressing hydraulic material characterized by having a step of static curing within 1 day to 30 days in a state where the dust generation suppression hydraulic material obtained in the addition step is packed in a bag. Production method. In the manufacturing method of the dust generation suppression type hydraulic material according to claim 1 or 2,
The dust-reducing hydraulic material, wherein the aliphatic polyhydric alcohol or the ether compound is one or more selected from ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin or liquid paraffin Manufacturing method. In the manufacturing method of the dust generation suppression type hydraulic material according to any one of claims 1 to 3,
A method of producing a dust-suppressing hydraulic material characterized by containing at least one kind of Portland cement, lime, mixed cement, soil-improving solidifying material or special cement as the hydraulic material to be used.

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