JP5895589B2 - Construction method of underwater non-separable grout composition - Google Patents

Description

  The present invention relates to a construction method of a grout composition used in an underwater environment in various construction works in the civil engineering and construction fields.

  Various works in the civil engineering and construction fields under the water environment have conventionally been provided with a weir around the structure, and after removing water with a pump, etc., in order to construct a general cement composition or grout composition, There were many construction processes and the construction period was also long. In recent years, cement compositions and grout compositions having underwater non-separation performance that can be constructed without removing water around the structure have been proposed.

  In Patent Document 1, it has extremely high fluidity and self-fillability without increasing the amount of mixed water on site and adding a large amount of water reducing agent, and can maintain fluidity for the initial and long term. For the purpose of providing a cement-based filling composition that can ensure underwater inseparability and high fluidity even when used in an underwater environment, a thickener and a water reducing agent are added to ordinary cement, There is disclosed a cement-based filling composition containing fine aggregates adjusted for the above.

  In Patent Document 2, for the purpose of providing an underwater non-separable mortar composition for high temperature environment that has excellent underwater inseparability even in a high temperature environment, can be kneaded in a short time, and has little change over time. A water-insoluble separable mortar composition containing a cement, an aggregate, a thickener, a fast-acting polycarboxylic acid-based water reducing agent and a slow-acting melamine-based water reducing agent is disclosed.

JP2009-149457 JP2009-161387

  However, when the grout slurry formed from the grout composition is pumped and filled in a construction site under an underwater environment to improve the fluidity and fluidity retention, the inseparability in water decreases, and the underwater environment There is a tendency for the degree of separation in water (amount of suspended solids) to increase. Moreover, when the non-separability of the grout slurry in water is improved, the fluidity and the fluid retention are lowered, and the pumpability and the filling property to the construction site tend to be lowered. In particular, when the decrease in fluidity is large, there is a tendency that the pumpability is reduced when the hose is clogged or when the operation is resumed after interruption. Furthermore, since the difference in operating temperature affects the fluidity and fluidity retention, the period from manufacture to use becomes longer, and the temperature changes greatly as the season changes. There is a risk that the property and the filling property to the construction site will deteriorate. Therefore, it is desired to form a cured body having both of these performances and excellent compressive strength in water and in the air.

  Therefore, the present invention has a balance between excellent fluidity and fluid retention that is not easily affected by temperature, and inseparability in water in a well-balanced manner, and has excellent pumpability and fillability to construction sites. It aims at providing the construction method of the grout composition which can form the hardening body which has the outstanding compressive strength in air | atmosphere.

  As a result of detailed studies, the present inventors have solved the above problem by a construction method using a grout composition in which two kinds of polycarboxylic acid-based fluidizing agents having different side chain lengths are used in combination at a specific content. As a result, the inventors have found out that the present invention can be achieved.

  That is, the present invention uses a grout slurry generating apparatus to continuously knead a grout composition and water to produce a grout slurry, and to construct the grout slurry at a construction site. The grout composition comprises Portland cement, fine aggregate, thickener and fluidizing agent, and the fluidizing agent has a side chain length of more than 50 nm. Two types of fluidizing agent a) and polycarboxylic acid type fluidizing agent (fluidizing agent b) having a side chain length of 50 nm or less are used in combination, and the total amount (100% by mass) of the fluidizing agent is used as a reference. Provided is a construction method in which the content ratio of the fluidizing agent a and the fluidizing agent b is 10:90 to 90:10.

  According to the construction method of the grout composition of the present invention, the specific grout composition is excellent in fluidity and fluidity that are hardly affected by temperature, and in water inseparability in a balanced manner. The grout slurry prepared from the grout composition has extremely excellent pumpability and filling ability to the construction site, and can form a cured body having excellent compressive strength in water and in the air. Therefore, a concrete structure having a sufficiently high strength can be obtained after the construction by the construction method. Moreover, in the said construction method, mass production can be performed at a construction site by continuously generating grout slurry, and the effect of shortening the construction period can be achieved.

  When the above-mentioned thickener is a cellulose-based thickener, and the viscosity of the 2% by weight aqueous solution of the thickener at 20 ° C. is 30000 to 60000 mPa · s, the non-separability of the grout composition in water is more reliably ensured. Can be improved.

  When the particle size of the fine aggregate contained in the grout composition is 150 μm or more and less than 1200 μm, the workability of the grout slurry is further improved, and a cured body having excellent strength characteristics can be formed.

  In the construction method of the present invention, the grout slurry generating device includes a plurality of blades formed on the outer peripheral surface of the shaft member, and the shaft member rotates to knead the grout composition and water while mixing the base member of the shaft member. Contains a kneading device provided with a kneading screw for transferring the grout slurry from the side toward the terminal side, a hopper having a hopper screw for transferring the grout composition to the kneading device, and a grout slurry discharged from the kneading device And a snake pump for discharging the grout slurry in the reservoir to the outside, and a transfer pipe for transferring the grout slurry discharged from the snake pump.

  By using such a grout slurry generating device, it is possible to continuously generate grout slurry, which makes it possible to place a large amount on the construction site, and to more reliably obtain the effect of shortening the construction period. it can.

  Moreover, the grout slurry production | generation apparatus further comprises the grout composition supply apparatus which supplies a grout composition to a hopper, and makes mass casting of grout slurry more reliable.

  Furthermore, the grout slurry production | generation apparatus is further provided with the water supply apparatus which supplies water to a kneading apparatus, and enables construction in the place without water supply equipment.

  When the grout slurry generating apparatus is mounted on a vehicle, the grout composition can be moved to the construction site or constructed on site more easily.

  According to the present invention, excellent fluidity and fluidity that are not easily affected by temperature, and in-water non-separability are balanced, and have excellent pumpability and filling ability to the construction site. The construction method of the grout composition which can form the hardening body which has the outstanding compressive strength in the air can be provided. Moreover, in the construction method of the present invention, by continuously generating the grout slurry, a large amount can be placed at the construction site, and the construction period can be shortened.

It is a figure which shows typically a grout slurry production | generation apparatus. It is a rear view which shows typically the grout slurry production | generation apparatus mounted in the vehicle. It is a side view which shows typically the grout slurry production | generation apparatus mounted in the vehicle. It is a figure which shows a V funnel typically.

  The construction method of the grout composition of the present invention includes a step of continuously kneading the grout composition and water using a grout slurry production device to produce a grout slurry, and a step of constructing the grout slurry at the construction site. Have

  A preferred embodiment of a construction method for a grout composition according to the present invention will be described below with reference to the drawings.

<Grout slurry generator>
FIG. 1 is a diagram schematically showing a grout slurry generating apparatus according to this embodiment. In the grout slurry generating apparatus according to the present embodiment, a plurality of blades are formed on the outer peripheral surface of the shaft member, and the shaft member rotates in a predetermined direction, whereby the grout composition and water are kneaded while mixing the grout composition and water. A kneading device 2b provided with a kneading screw 26 for transferring the kneaded material (grouting slurry) from the end to the end side, a hopper 2a having a hopper screw 22 for transferring the grout composition to the kneading device 2b, and a kneading device A reservoir 2c for storing the grout slurry discharged from the reservoir, a snake pump 2d for discharging the grout slurry in the reservoir 2c to the outside, and a transfer pipe 2e for transferring the grout slurry discharged from the snake pump 2d And preferably.

  As shown in FIG. 1, the grout slurry generator includes a hopper 2a, a kneading device 2b, a reservoir 2c, a snake pump 2d, a transfer pipe 2e, an operation panel 2f, and a water supply port 27, and a grout composition and water are supplied. Continuously kneaded to produce a grout slurry.

  The hopper 2a supplies the supplied grout composition to the kneading apparatus 2b side. The hopper 2a has a wide opening 21 formed in the upper part of the main body of the hopper 2a, and has an opening communicating with the adjacent kneading device 2b in the lower side wall of the main body. And the hopper screw 22 is provided substantially horizontally in the main body lower part of the hopper 2a, and is rotationally driven by the motor 23 installed in the exterior of the hopper 2a. In this case, the rotational driving force by the motor 23 is transmitted to the hopper screw 22 side via the power transmission belt 24. Here, a hydraulic or electric motor 23 is used.

  The hopper screw 22 is formed such that a spiral blade is wound around the outer peripheral surface. Here, the grout composition charged into the charging port 21 is transferred to the kneading device 2 b by the rotational movement of the hopper screw 22.

  The kneading apparatus 2 b includes a kneading chamber 25 and a kneading screw (mixer screw) 26. The kneading chamber 25 has a cylindrical shape (hollow cylindrical shape) and is installed so that the longitudinal direction is substantially horizontal. The kneading chamber 25 is provided with an opening communicating with the lower part in the hopper 2a at one end of the two ends in the longitudinal direction, and an opening communicating with the discharge unit 28 in the vicinity of the other end. Is provided. A mixer screw 26 is installed inside the kneading chamber 25 along the longitudinal direction. The kneading apparatus 2b kneads the grout composition transferred from the hopper 2a by the rotation of the mixer screw 26 together with water in the kneading chamber 25. Here, a water supply port 27 communicating with the transfer pipe 6b is formed at a predetermined position on the side of the hopper 2a on the side wall of the kneading chamber 25, and the inside of the kneading chamber 25 is connected to the transfer pipe 6b and the water supply port 27. Is supplied with water.

  Further, the discharge unit 28 communicates the kneading chamber 25 and the reservoir 2c, and discharges the grout slurry kneaded in the kneading chamber 25 to the reservoir 2c. The mixer screw 26 is formed integrally with the hopper screw 22 of the hopper 2 a (or is connected and fixed), and is rotated together with the hopper screw 22 by a motor 23.

  The rotation speed of the mixer screw 26 is 300 rpm or more, preferably 400 rpm, more preferably 500 rpm or more, and still more preferably 600 rpm or more. Thus, since the rotation speed of the mixer screw 26 is as high as 300 rpm or more, the grout slurry is more sufficiently kneaded. Here, the rotation speed of the mixer screw 26 can be set to a desired value by an operator operating an operation panel 2f described later.

  The reservoir 2c is for temporarily storing the kneaded material (grouting slurry) discharged from the kneading apparatus 2b via the discharge portion 28. Since the grout slurry is once stored in the reservoir 2c in this way, the grout slurry can be discharged from the reservoir 2c at a desired ratio (discharge amount) by the snake pump 2d.

  The reservoir 2c has a wide opening 29 formed in the upper part of the main body, and a stirrer screw 30 and a transfer screw 31 provided substantially horizontally in the lower part of the main body. Each of the stirrer screw 30 and the transfer screw 31 has a length from substantially one side to the other of two side walls facing each other in the lower part of the main body of the reservoir 2c. The stirrer screw 30 is rotationally driven by a motor 32, and the transfer screw 31 is rotationally driven by a motor 33. The rotational driving force by the motor 33 is transmitted to the transfer screw 31 side via the power transmission belt 34. Here, the motors 32 and 33 are hydraulic or electric.

  An opening communicating with the adjacent snake pump 2d is formed on the lower side wall of the reservoir 2c. Through this opening, the transfer screw 31 in the reservoir 2c and the screw (not shown) in the snake pump 2d are integrally connected (formed). For this reason, the screw in the snake pump 2 d rotates with the rotation of the transfer screw 31. As the screw in the snake pump 2d rotates in this way, the grout slurry in the reservoir 2c is discharged to the outside through the transfer pipe 2e.

  The operation panel 2f includes various operation levers for the operator to operate the rotational drive of the hopper screw 22, the mixer screw 26, the stirrer screw 30 and the transfer screw 31 installed in each of the hopper 2a, the kneading device 2b and the reservoir 2c. And various operation switches. Furthermore, the operation panel 2 f is connected to a transfer pipe 6 b that transfers water as necessary, and has a water adjustment valve and a water meter that adjust the amount of water supplied to the water supply port 27.

  In the grout slurry generator having the above-described configuration, the grout composition charged into the hopper 2 a is transferred to the kneading device 2 b by the rotation of the hopper screw 22. In the kneading apparatus 2b, the grout composition transferred from the hopper 2a is kneaded with the water supplied through the water supply port 27 by the rotation of the mixer screw 26, and a grout slurry having a desired property is generated. The grout slurry generated by the kneading device 2b is discharged to the reservoir 2c through the discharge unit 28, and is temporarily stored while being stirred by the rotation of the stirrer screw 30. The stirred grout slurry is transferred to the snake pump 2d by the rotation of the transfer screw 31, and further discharged to the outside from the snake pump 2d through the transfer pipe 2e.

  The grout slurry production | generation apparatus can be equipped with the grout composition supply apparatus as needed. And if it is an apparatus which can automatically supply a powder raw material to the hopper 2a continuously, a commercially available apparatus can be used in combination.

  As shown in FIG. 2 and FIG. 3 as an example of a grout composition supply device, a grout composition tank 5a for automatically supplying a grout composition to a mixer pump, containing the grout composition, and this grout composition Screw conveyors 5b and 5c for transferring the grout composition in the tank 5a to the hopper 2a side. A screw conveyor 5c is arranged on the bottom of the main body of the grout composition tank 5a, and a discharge port for discharging the grout composition to the screw conveyor 5b is formed. An opening 53 for receiving supplementary supply is formed.

  The screw conveyor 5b is for transferring the grout composition in the powder raw material tank 5a to the hopper 2a side, and one end is located at the discharge port of the screw conveyor 5c arranged on the bottom of the main body of the grout composition tank 5a. At the other end, a discharge port 52 for discharging the grout composition is formed. The discharge port 52 is located near the input port 21 of the hopper 2a. In the screw conveyor 5b, the powder raw material discharged from the discharge port of the powder raw material tank 5a is transferred to the discharge port 52, and is discharged from the discharge port 52 to the hopper 2a.

  The grout slurry production | generation apparatus can be equipped with a water supply apparatus as needed. And if it is an apparatus which can be connected with the water supply port 27 and can supply water, a commercially available apparatus can be used in combination.

  FIG. 2 is a rear view schematically showing the grout slurry generating device mounted on the vehicle, and FIG. 3 is a side view schematically showing the grout slurry generating device mounted on the vehicle.

  The grout slurry generator can be mounted on a vehicle 71 such as a truck as necessary. For example, as shown in FIG. 2 and FIG. 3, a grout slurry generation device including a grout composition supply device and a water supply device can be arranged on the loading platform portion of a vehicle 71.

  As shown in FIGS. 2 and 3 as an example of the water supply device, the water supply device includes a water tank 6a for storing water and a transfer pipe for transferring the water stored in the water tank 6a to the kneading device 2b. 6b, a water supply pump 6c that pumps up water stored in the water tank 6a, a water adjustment valve that adjusts the supply amount of water supplied into the kneading apparatus 2b, and a flow meter. The water is adjusted by the operator operating the water adjustment valve while visually checking the flow meter. The flow meter and the water adjustment valve are disposed in the vicinity of the operation panel 2f, but are particularly preferably disposed at a place where the flow meter and the water adjustment valve are easy to operate and easy to see. For example, the operation panel 2f and a transfer pipe 6b for transferring water can be connected, and a water adjustment valve and a water meter for adjusting the amount of water supplied to the water supply port 27 can be incorporated in the operation panel 2f. .

  By using such a grout slurry production | generation apparatus, a grout slurry can be produced | generated continuously, mass placement at a construction site becomes possible, and a construction period can be shortened.

<Grout composition>
Next, an example of the grout composition according to this embodiment will be described. The grout composition of this embodiment has Portland cement, fine aggregate, thickener and fluidizing agent, and the fluidizing agent is a combination of two polycarboxylic acid based fluidizing agents having different side chain lengths. It is a grout composition whose content ratio satisfies a specific relationship.

  As Portland cement, it is preferable to use at least one selected from ordinary Portland cement, early-strength Portland cement, ultra-early strong Portland cement, moderately hot Portland cement, sulfate-resistant Portland cement, low heat Portland cement and white Portland cement.

  As the fine aggregate, at least one selected from sands such as quartz sand, river sand, land sand, sea sand and crushed sand can be used. The fine aggregate preferably has a particle size in the range of 150 μm or more and less than 1200 μm.

  Specifically, the fine aggregate preferably does not include particles having a particle diameter of less than 150 μm and particles having a particle diameter of 1200 μm or more, but preferably includes particles having the following particle diameter. That is, the fine aggregate is a particle having a particle diameter of 850 μm or more and less than 1200 μm, more than 0 mass% and less than 20 mass%, a particle diameter of 600 μm or more and less than 850 μm is 25 to 45 mass%, and a particle diameter of 425 μm or more and less than 600 μm is 35 to 55. 5% by mass of particles having a particle size of 300 μm or more and less than 425 μm, 5% by mass or more of particles of 212 μm or more but less than 300 μm, and 0-5% by mass of particles having a particle size of 150 μm or more but less than 212 μm. It is more preferable to contain each in the ratio.

  The fine aggregate is 5 to 15% by mass of particles having a particle size of 850 μm or more and less than 1200 μm, 20 to 40% by mass of particles having a particle size of 600 μm or more and less than 850 μm, 40 to 50% by mass of particles having a particle size of 425 μm or more and less than 600 μm, 10 to 20% by mass of particles having a particle size of 300 μm or more and less than 425 μm, more than 0% by mass to 3% by mass or less of particles having a particle size of 212 to 300 μm, and 0 to 3% by mass of particles having a particle size of 150 to 212 μm. More preferably.

  The grout composition according to the present embodiment includes fine aggregates having a particle size in the above-described range, thereby obtaining excellent fluidity and fluid retention that are not easily affected by temperature. Can be further improved, and excellent non-separability in water can be achieved in a balanced manner. And the compressive strength in water and the air is high, and the hardening body which achieves the outstanding underwater strength ratio more reliably can be obtained.

  The particle diameter of the fine aggregate can be measured by using several sieves having different nominal dimensions as defined in JIS Z 8801: 2006. In the present specification, “the mass ratio of particles having a particle diameter of 850 μm or more and less than 1200 μm” means that when a sieve having a sieve size of 1200 μm is used, the sieve has a sieve size of 1200 μm and a sieve having a sieve size of 850 μm. The mass ratio with respect to the whole fine aggregate of the particle | grains which remain | survive on a 850-micrometer sieve when using a sieve is said.

  The content of fine aggregate in the grout composition of the present embodiment is preferably 50 to 120 parts by mass, more preferably 60 to 100 parts by mass, and still more preferably 70 to 100 parts by mass of Portland cement. It is -90 mass parts, Most preferably, it is 75-85 mass parts.

  By making the content of the fine aggregate in the above-mentioned range, the grout composition can achieve both excellent fluidity and fluid retention that is not easily affected by temperature, and water inseparability in a more balanced manner, and a pump. It is possible to further improve the pumpability and the filling property to the construction site, and to obtain a cured body that has a higher compressive strength in water and in the air and exhibits an excellent underwater strength ratio in the air.

  As the thickener, it is preferable to use a cellulose-based thickener. The cellulosic thickener is not particularly limited, but a cellulosic thickener having in-water non-separation performance is more preferable. By using such a cellulosic thickener, the fluidity and fluid retention of the grout composition can be further improved, and the inseparability in water can be further improved. And the compression body in water and the air is high, and the hardening body which achieves the outstanding underwater strength ratio more reliably can be produced.

  Examples of cellulose thickeners include thickeners containing water-soluble cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, glyoxal-added hydroxypropylmethylcellulose, carboxymethylcellulose, and carboxyethylcellulose. In particular, it is preferable to use a hydroxypropylmethylcellulose-based thickener having an underwater non-separation performance.

  The grout composition has a good balance between excellent fluidity and flow retention that is not easily affected by temperature and inseparability in water, and has excellent pumpability and filling ability to the construction site. The viscosity of the 2% by weight aqueous solution at 20 ° C. is preferably 30000 to 60000 mPa · s, more preferably 35000 to 55000 mPa · s, still more preferably 38000 to 52000 mPa · s, and particularly preferably 40000. ˜50000 mPa · s.

  The viscosity of the thickener was determined by using a 2% by weight aqueous solution of the thickener using a B-type viscometer (digital viscometer DVL-B type manufactured by Toki Sangyo Co., Ltd.). 4. It is the value measured on the conditions of 20 degreeC.

  It is preferable that content of the thickener in the grout composition of this embodiment is 0.05-0.65 mass part with respect to 100 mass parts of Portland cement, and is 0.15-0.55 mass part. More preferably, it is 0.25-0.45 mass part, More preferably, it is 0.30-0.40 mass part.

  By making the content of the thickener in the above-mentioned range, the grout composition can balance both excellent fluidity and fluid retention that is not easily affected by temperature and non-separability in water, and a pump. It is possible to further improve the pumpability and the filling property to the construction site, and to obtain a cured body that has a higher compressive strength in water and in the air and exhibits an excellent underwater strength ratio in the air.

  As a fluidizing agent, the mixing amount of the grout composition with water is reduced to reduce the blending amount of water when producing a grout slurry, exhibiting excellent fluidity, and excellent compressive strength in water and in the air after curing. In order to obtain, a polycarboxylic acid type fluidizing agent is used. In addition, the fluidity immediately after kneading of the grout slurry and the fluidity (flow retention) after a long period of time (for example, after 20 to 60 minutes) are less affected by the temperature and are further improved. A fluidizing agent having a side chain length of more than 50 nm (hereinafter referred to as “fluidizing agent a”), and a fluidizing agent having a side chain length of 50 nm or less that is excellent in long-term fluidity (hereinafter referred to as “fluidizing agent b”). ")."

The fluidizing agent a preferably contains a polymer having no ester bond in the side chain, more preferably contains at least a polymer having a structural unit represented by the following formula (A2), and the following formulas (A2) and ( It is further preferable to include a polymer having the structural unit represented by B). In formula (A2), R represents a hydrogen atom or a polyoxyethylene group, and is particularly preferably a polyoxyethylene group. That is, the fluidizing agent a preferably contains a polymer having a polyoxyethylene chain (POE: — (OC ₂ H ₄ ) _n —) as a side chain.

  The repeating number n of the oxyethylene group which is the unit structure of the polyoxyethylene chain is preferably 50 to 200, more preferably 80 to 190, still more preferably 120 to 180, specifically. Is preferably 160.

  The polymer constituting the fluidizing agent a has a sodium content measured using an inductively coupled plasma (ICP) emission spectrometer, preferably more than 2000 μg / g and not more than 3500 μg / g, more preferably from 2200 to 3300 μg / g. More preferably, it is 2400-3000 microgram / g, Most preferably, it is 2600-2800 microgram / g, It is good to be 2700 microgram / g specifically.

The fluidizing agent b preferably contains a polymer having an ester bond in the side chain, more preferably contains a polymer having at least a structural unit represented by the following formula (C), and the following formulas (A) and (B It is more preferable that the polymer has a structural unit represented by (C) or (C). That is, the fluidizing agent b preferably contains a polymer having a side chain of a polyoxyethylene chain (POE: — (OC ₂ H ₄ ) _m —) as an ester bond.

  The repeating number m of the oxyethylene group which is the unit structure of the polyoxyethylene chain is preferably 30 to 50, more preferably 35 to 48, still more preferably 40 to 45, specifically. Should be 42.

  The ratio of the number of structural units represented by the formula (A) and the number of structural units represented by the formula (C) of the polymer constituting the polycarboxylic acid-based fluidizing agent of the fluidizing agent b is preferably 9: 1 to 5: 5, more preferably 8: 2 to 6: 4, still more preferably 7.5: 2.5 to 6.5: 3.5, particularly preferably 7.2: 2.8 to 6.8: 3.2, specifically 7: 3.

  The polymer constituting the fluidizing agent b preferably has a sodium content measured by an inductively coupled plasma (ICP) emission spectrometer using an inductively coupled plasma (ICP) emission spectrometer, preferably 3000 to 20000 μg / g. Preferably it is 5000-15000 microgram / g, More preferably, it is 7500-12500 microgram / g, Most preferably, it is 8500-11000 microgram / g, It is good to be 9900 microgram / g specifically.

  The content ratio of the fluidizing agent a and the fluidizing agent b based on the total amount (100% by mass) of the fluidizing agent in the grout composition of the present embodiment is 10:90 to 90:10, preferably 20:80. It is -80: 20, More preferably, it is 30: 70-70: 30, More preferably, it is 40: 60-60: 40, Especially preferably, it is 45: 55-55: 45.

  By setting the content ratio of the fluidizing agent a and the fluidizing agent b in the fluidizing agent within the above-mentioned range, the initial fluidity and long-term fluidity (fluid retention) of the grout composition are affected by the temperature. It is difficult to receive and can be made even better.

  The total content of the fluidizing agent in the grout composition of the present embodiment is preferably 0.05 to 0.65 parts by mass with respect to 100 parts by mass of Portland cement, and 0.15 to 0.55 parts by mass. It is more preferable that it is 0.25-0.45 mass part, and it is especially preferable that it is 0.30-0.40 mass part.

  By making the content of the total amount of the fluidizing agent in the above-mentioned range, the grout composition can balance both excellent fluidity and fluid retention that is not easily affected by temperature and non-separability in water in a balanced manner. The grout slurry prepared from the grout composition is hardly affected by temperature and has extremely excellent pumpability and filling property to the construction site, and a grout cured body having excellent compressive strength in water and in the air. Can be formed. Therefore, a concrete structure having a sufficiently high strength can be obtained after applying the grout slurry. In addition, since the grout slurry is continuously generated, a large amount of casting can be performed at the construction site, so that the construction period can be shortened.

  The grout composition of this embodiment can further contain an inorganic expansion material. As the inorganic expansion material, quick lime-gypsum expansion material, gypsum expansion material, calcium sulfoaluminate expansion material and the like can be used. Among these, from the viewpoint of further improving the compressive strength of the cured body in water and in the air, it is preferable to include a quicklime-gypsum-based expansion material.

  The content of the inorganic expansion material is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass, and further preferably 3 to 7 parts by mass with respect to 100 parts by mass of Portland cement. Preferably it is 4-6 mass parts.

  By adjusting the content of the inorganic expansive material to the above-mentioned range, more appropriate expansibility is expressed, and excessive shrinkage of the grout cured body can be suppressed, and cracks caused by excessive expansive action can be suppressed. Generation | occurrence | production can fully be suppressed.

<Grout slurry>
The grout slurry of this embodiment can be prepared by blending the above-mentioned grout composition and water and kneading. A preferred embodiment of the grout slurry is described below.

  The grout slurry of this embodiment can be suitably used as an underwater non-separated grout slurry. When preparing the grout slurry, the flow value of the grout slurry, the flow value after 60 minutes, and the amount of suspended substances can be adjusted by appropriately changing the amount of water. Here, the flow value and the flow value after 60 minutes are the same as in the test method described in JSCE-D 104-2007 “Underwater separable admixture quality standard for concrete, 6.1.6 (1) Slump flow”. The flow value (unit: mm) measured immediately after kneading in conformity and the flow value (unit: mm) measured 60 minutes after kneading. However, in this embodiment, measurement is performed using a flow cone described in JIS R 5201-1997 “Physical Test Method for Cement”. The funnel flow-down value is the funnel flow-down value (unit: seconds) measured immediately after kneading in accordance with the test method described in JSCE-F 512-2007 “flow test method using high-fluidity concrete funnel”. . However, in this embodiment, the measurement is performed using the V funnel shown in FIG. The amount of suspended solids conforms to the test method described in JSCE-D 104-2007 “Quality Standards for Underwater Inseparable Admixture for Concrete, Appendix 2: Method for Testing Underwater Separability of Underwater Inseparable Concrete”. (Unit: mg / L).

  The amount of water is preferably 20 to 28 parts by mass, more preferably 21 to 27 parts by mass, and further preferably 21.5 to 26.5 parts by mass with respect to 100 parts by mass of the grout composition. Especially preferably, it is 22-26 mass parts.

  The flow value of the grout slurry of this embodiment is preferably 210 to 290 mm, more preferably 220 to 280 mm, still more preferably 225 to 275 mm, and particularly preferably 230 to 270 mm.

  By setting the flow value within the above range, a grout slurry having even better fluidity can be obtained.

  The flow value after 60 minutes of the grout slurry of this embodiment is preferably 200 to 260 mm, more preferably 205 to 250 mm, still more preferably 208 to 245 mm, and particularly preferably 210 to 240 mm.

  By setting the flow value after 60 minutes within the above-mentioned range, it is possible to obtain a grout slurry having even better flow retention.

  In the flow value of the grout slurry of this embodiment, the difference (flow difference) between the maximum value and the minimum value of the flow value at 5 ° C., 20 ° C. and 30 ° C. is preferably 50 mm or less, more preferably 40 mm or less, More preferably, it is 30 mm or less.

  In the flow value after 60 minutes of the grout slurry of this embodiment, the difference (flow difference) between the maximum value and the minimum value of the flow value at 5 ° C., 20 ° C. and 30 ° C. is preferably 60 mm or less, and 50 mm or less. Is more preferable, and 45 mm or less is still more preferable.

  By making the flow difference in the above-mentioned range, it is possible to achieve a balance between even better fluidity and fluid retention that is not easily affected by temperature and non-separability in water, as well as pumpability and filling of construction sites. A grout slurry capable of further improving the properties can be obtained.

  The funnel flow down value of the grout slurry is preferably 25 seconds or less, more preferably 24 seconds or less, still more preferably 23 seconds or less, and particularly preferably 22 seconds or less.

  By making the funnel flow-down value in the above-mentioned range, it is possible to balance both excellent fluidity and fluid retention that is not easily affected by temperature, and underwater inseparability in a well-balanced manner. A grout slurry capable of further improving the filling property can be obtained.

  The amount of suspended substances in the grout slurry of this embodiment is preferably 100 mg / L or less, more preferably 80 mg / L or less, still more preferably 60 mg / L or less, and particularly preferably 50 mg / L (liter). )

  By setting the amount of suspended solids within the above range, a grout slurry having better water inseparability can be obtained.

<Hard grout>
The grout hardening body of this embodiment can be obtained by hardening the above-mentioned grout slurry. A preferred embodiment of the grout cured body will be described below.

  The grout hardening body of this embodiment can be used suitably as an underwater non-separation grout hardening body. That is, the grout cured product of the present embodiment formed by curing the grout slurry described above has a sufficiently high compressive strength in water and in the air, and has an excellent underwater / air strength ratio (compressed strength in water / air (Compressive strength inside).

  Here, the compressive strength (in water and in the air) is a value measured in accordance with JSCE-D 104-2007 “Quality Standard for Underwater Non-Separable Admixture for Concrete, 6.1.6 (6) Compressive Strength”. It is. However, in this embodiment, a cylindrical specimen having a diameter of 50 mm and a height of 100 mm is used as a specimen (grout cured body), and measurement is performed at a predetermined age. The underwater air-to-air strength ratio is a value calculated according to underwater JSCE-D 104-2007 “Underwater separable admixture quality standard for concrete, 6.1.7 (7) Underwater air-to-air strength ratio”. It is.

The compressive strength (in water) at the age of 7 days of the cured grout of this embodiment is preferably 15.0 N / mm ² or more, more preferably 20.0 N / mm ² or more, and even more preferably 30. 0 N / mm ² or more, particularly preferably 40.0 N / mm ² or more.

The compressive strength (in the air) at 7 days of age of the grout cured product of this embodiment is preferably 19.0 N / mm ² or more, more preferably 25.0 N / mm ² or more, and even more preferably 38. 0.0 N / mm ² or more, particularly preferably 50.0 N / mm ² or more.

The compressive strength (in water) of the cured grout of this embodiment on the 28th day of age is preferably 25.0 N / mm ² or more, more preferably 35.0 N / mm ² or more, and even more preferably 40. 0 N / mm ² or more, particularly preferably 44.0 N / mm ² or more.

The compressive strength (in the air) of the cured grout of this embodiment on the age of 28 is preferably 32.0 N / mm ² or more, more preferably 44.0 N / mm ² or more, and further preferably 50. 0.0 N / mm ² or more, particularly preferably 55.0 N / mm ² or more.

  The strength ratio in water / air at the age of 7 days and 28 days of the cured grout of this embodiment (compressive strength in water / compressive strength in air × 100) is preferably 80% or more, More preferably, it is 82% or more, More preferably, it is 84% or more, Most preferably, it is 85% or more.

  When the compressive strength in water and in the air and the strength ratio in air are in the above-mentioned range, the grout cured body has excellent strength characteristics even when the construction site is under water.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  Hereinafter, the contents of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Raw materials]
The raw materials shown in the following (1) to (5) were prepared.
(1) Portland cement / Hayachi Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area = 4500 cm 2 / g)
(2) Fine aggregate / silica sand: having a particle size distribution as shown in Table 1.

(3) Thickener / Hydroxypropylmethylcellulose thickener (manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 43600 mPa · s)
(4) Fluidizing agent / fluidizing agent a (manufactured by BASF, side chain length: 76 nm, having structural units represented by formulas (A2) and (B), number of repeating units of oxyethylene group n: 160, Na amount: 2700 μg / g)
-Fluidizing agent b (manufactured by BASF, side chain length: 35 nm, having structural units represented by formulas (A), (B) and (C), number of repeating units of oxyethylene group m: 42, Na amount: 9900 μg / g)
(5) Inorganic expansive material, quicklime-gypsum expansive material (manufactured by Taiheiyo Materials Co., Ltd.)

[Preparation of grout composition]
(1) Portland cement, (2) fine aggregate, (3) thickener, (4) fluidizing agent, and (5) inorganic expansion material are blended in the proportions (parts by mass) shown in Table 2, The grout composition of each example and each comparative example was prepared.

[Preparation of grout slurry]
460 g of water (23 parts by mass of water with respect to 100 parts by mass of the grout composition) is blended and kneaded to 2 kg of each grout composition obtained in the examples and comparative examples, and each example and each comparative example. A grout slurry was prepared. The kneading was performed for 2 minutes at a rotation speed of 700 rpm using a Chemistrarer under the conditions of each temperature-controlled room (5, 20, 30 ° C.) and relative humidity 65%.

[Evaluation method of grout slurry]
[Evaluation of grout slurry]
The flow value, flow difference, funnel flow-down value, and suspended solid content of the prepared grout slurries of Examples and Comparative Examples were measured by the following methods. Table 3 shows the measurement results. Here, “-” in Table 3 represents unmeasured.

(1) Flow value The flow value was measured in accordance with the test method described in JSCE-D 104-2007 "Quality standard for water inseparable admixture for concrete, 6.1.6 (1) Slump flow". When the flow cone is the one described in JIS R 5201-1997 “Cement physical test method”, the grout slurry immediately after kneading is filled into the flow cone, and immediately after the flow cone is pulled up, 5 minutes have passed. The flow value was measured. Moreover, after the said grout slurry was left still for 60 minutes, the said procedure was repeated and the flow value 60 minutes after was measured. The flow value was used as an indicator of fluidity (initial fluidity), and the flow value after 60 minutes was used as an indicator of fluidity retention (long-term fluidity). Moreover, the flow value immediately after kneading and the flow value after 60 minutes were used as indicators of the filling property at the construction site.
(2) Flow difference About the flow value obtained by the above test method and the flow value after 60 minutes, the difference between the maximum value and the minimum value of the flow value at 5 ° C, 20 ° C and 30 ° C is used as the flow difference. The degree of influence on fluidity and fluidity retention due to differences in temperature, that is, an index of workability.

(3) Funnel flow down value Using the V funnel shown in FIG. 4, the funnel flow down value was measured in accordance with the test method described in JSCE-F 512-2007 “flow test using high fluid concrete funnel”. did. In addition, the funnel flow-down value was used as an index of pumpability and fillability at the construction site.

(4) Suspended matter amount Based on the test method described in JSCE-D 104-2007 “Quality Standards for Underwater Inseparable Admixture for Concrete, Appendix 2: Method for Testing Underwater Separability of Underwater Inseparable Concrete” The amount of suspended material was measured. The amount of suspended matter was used as an index of inseparability in water.

[Evaluation of cured grout]
(3) Compressive strength The compressive strength of the cured grout produced using the grout slurry prepared in a constant temperature room at 20 ° C. in Example 1 in water and in the air is defined as JSCE-D 104-2007 “2. It was measured in accordance with the test method described in “Inseparable Admixture Quality Standard, 6.1.6 (6) Compressive Strength”. However, it measured at each material age on the 7th and 28th using the cylindrical specimen with a diameter of 50 mm and a height of 100 mm as a specimen (grouting hardened body). Table 4 shows the measurement results.

(4) In-air strength ratio Underwater strength ratio of the hardened grout prepared using the grout slurry prepared in a constant temperature room at 20 ° C. in Example 1 is defined as JSCE-D 104-2007 “2. It was calculated according to the test method described in “Inseparable Admixture Quality Standard, 6.1.7 (7) In-air strength ratio in water”. The results are shown in Table 4.

  As shown in Table 3, the grout slurry of Example 1 exhibits good fluidity and fluid retention that is not easily affected by temperature, and identifies two types of polycarboxylic acid-based fluidizing agents having different side chain lengths. It was confirmed that the grout composition used at a content ratio of 1 has good pumpability and good filling property to the construction site. Moreover, it was confirmed from the measurement result of the suspended solid amount of the grout slurry of Example 1 that the grout composition has good inseparability in water.

  From the measurement result of the funnel flow-down value of the grout slurry in Example 1, it was confirmed that the grout composition of the Example has excellent pumpability and filling property to the construction site. Therefore, by the construction method of the grout composition of the present invention, it is possible to produce a grout slurry using a grout slurry production device and to place a large amount in the construction site.

  Moreover, as shown in Table 4, the grout hardening body (Example 2) produced using the grout slurry of Example 1 had favorable compressive strength and underwater air-in-air strength ratio in water and air. .

  From the above, the grout composition in which two kinds of polycarboxylic acid-based fluidizing agents having different side chain lengths are used in combination at a specific content ratio is excellent in fluidity, fluidity retention, and pump that are hardly affected by temperature. A hardened body having compressibility in water and in the air can be formed by a construction method using the pumping property, the filling property to the construction site, and the inseparability in water and using this. In particular, a large amount of grout slurry can be placed by the construction method of the present invention.

  2a ... hopper, 2b ... kneading device, 2c ... reservoir, 2d ... snake pump, 2e ... transfer pipe, 2f ... operation panel, 21 ... loading port, 22 ... hopper screw, 23 ... motor, 24 ... power transmission belt, 25 ... Kneading chamber, 26 ... kneading screw, 27 ... water supply port, 28 ... discharge port, 29 ... expanding part, 30 ... stirrer screw, 31 ... transfer screw, 32, 33 ... motor, 34 ... power transmission belt, 5a ... grout composition Material tank, 5b, 5c ... screw conveyor, 51 ... grout composition, 52 ... discharge port, 53 ... opening, 6a ... water tank, 6b ... transfer pipe, 6c ... water pump, 71 ... vehicle.

Claims (7)

With grout slurry generator, and kneaded continuously underwater nondisjunction grout composition and water, generating a grout slurry, water nondisjunction grout composition and a step of applying the grout slurry in a construction site A construction method of an object,
The underwater non-separable grout composition comprises Portland cement, fine aggregate, thickener and fluidizing agent,
The fluidizing agent includes a polycarboxylic acid fluidizer (fluidizer a) having a side chain length of more than 50 nm and a polycarboxylic acid fluidizer (fluidizer b) having a side chain length of 50 nm or less. Two types are used together,
The repeating number n of the oxyethylene group which is the unit structure of the polyoxyethylene chain of the fluidizing agent a is 120 to 180,
The sodium content of the fluidizing agent a is 2400 to 3000 μg / g,
The repeating number m of the oxyethylene group which is the unit structure of the polyoxyethylene chain of the fluidizing agent b is 40 to 45,
The sodium content of the fluidizing agent b is 8500-11000 μg / g,
The content of the fluidizing agent a and fluidizing agent b and based on the total amount (100 mass%) of the fluidizer 45: 55-55: Ri 45 der,
The thickener is a cellulose-based thickener, and the viscosity of a 2% by weight aqueous solution of the thickener at 20 ° C. is 40000 to 50000 mPa · s,
With respect to 100 parts by mass of Portland cement, the total amount of the fluidizing agent is 0.15 to 0.55 parts by mass, the thickener is 0.05 to 0.65 parts by mass, and the fine aggregate is 60 to 100 parts by mass. is there,
Construction method. The said underwater non-separation grout composition contains a quick lime-gypsum expansion material further, The said quick lime-gypsum expansion material is 1-10 mass parts with respect to 100 mass parts of said Portland cement. Construction method. The construction method according to claim 1 or 2, wherein a particle diameter of the fine aggregate is in a range of 150 µm or more and less than 1200 µm. The grout slurry generator is
A plurality of blades are formed on the outer peripheral surface of the shaft member, and the shaft member rotates to grout from the base end side to the terminal end side of the shaft member while kneading the underwater non-separable grout composition and the water. A kneading apparatus provided with a kneading screw for transferring the slurry;
A hopper having a hopper screw for transferring the underwater non-separable grout composition to the kneading device;
A reservoir for containing the grout slurry discharged from the kneading device;
A snake pump for discharging the grout slurry in the reservoir to the outside;
The construction method of any one of Claims 1-3 provided with the transfer pipe for transferring the grout slurry discharged from the said snake pump. The grout slurry producing system further comprises a water nondisjunction grout composition supply device for supplying the water nondisjunction grout composition to said hopper, the construction method of claim 4.   The construction method according to claim 4 or 5, wherein the grout slurry generation device further includes a water supply device that supplies the water to the kneading device.   The construction method according to claim 4, wherein the grout slurry generation device is mounted on a vehicle.

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