Soil mortar manufacturing method and soil mortar manufacturing system

Abstract

To provide a production method for soil mortar and a soil mortar production system capable of simply and efficiently producing the soil mortar of a predetermined blending by using construction site soil.SOLUTION: A production method for soil mortar includes the steps of: measuring a water content of construction site soil; calculating a water amount of adjustment water; blending by a slurry mixer 2 cement, water, and an admixture according to a predetermined blending to form cement slurry; and blending by a continuous mixer 5 the construction site soil, the adjustment water, and the cement slurry to produce the soil mortar. A water amount of the adjustment water is calculated by subtracting a water amount of the cement slurry and the water amount of the construction site soil from the total water amount of the soil mortar defined by a blending design.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a soil mortar manufacturing method and a soil mortar manufacturing system. [Background technology]

[0002] In construction work involving earthwork, on-site generated soil may be mixed with cement-based solidification materials to be reused as soil mortar (including fluidized soil). When using soil mortar in a manner similar to that of concrete structures such as piles, the amount of cement is increased to increase the strength of the soil mortar. There are two types of soil mortar manufacturing methods: batch and continuous. The batch method of soil mortar manufacturing is carried out in a predetermined manufacturing unit (e.g., 1 m 3 In this method, a predetermined amount of material is put into a mixing tank equipped with a rotating mixing blade, mixed and stirred until the material becomes uniform, and then discharged, and this process is repeated. With the batch method, the mixing time can be adjusted according to the material being handled. However, with the batch method of producing soil mortar, it is necessary to measure the materials, then put them into the mixing tank, mix them, and discharge them from the mixing tank, which is a time-consuming process. On the other hand, in the continuous soil mortar manufacturing method, the materials are fed into a mixer at a predetermined ratio by adjusting the pumps and belt conveyers that supply each material, and soil mortar is manufactured continuously. Therefore, in the continuous manufacturing method, it is not necessary to repeat the cycle of measuring, mixing, and discharging, and soil mortar can be manufactured efficiently. For example, Patent Document 1 discloses a manufacturing method for manufacturing soil mortar by feeding on-site generated soil, cement, water, and refined clay into a continuous mixer. However, in the continuous manufacturing method, since a constant amount of the mixed soil is discharged at a constant speed by the mixer, the mixing time cannot be adjusted arbitrarily according to the material. If the mixing time is not appropriately adjusted, for example, when the on-site generated soil is mainly clayey soil, lumpy soil that is not mixed with cement tends to remain. In addition, when manufacturing high-strength soil mortar, the amount of cement is increased and the amount of water is reduced, so there is a risk that the cement will not be mixed uniformly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-60314 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to propose a soil mortar manufacturing method and a soil mortar manufacturing system that make it possible to easily and efficiently manufacture soil mortar of a predetermined mix ratio using on-site generated soil. [Means for solving the problem]

[0005] The method for producing soil mortar of the present invention for solving the above problems includes the steps of measuring the water content of the soil generated on site, calculating the amount of adjustment water, mixing cement, water and admixtures (water reducing agent, high performance water reducing agent, superplasticizer, air foaming agent, etc.) in a predetermined ratio to produce cement slurry, and mixing the soil generated on site, the adjustment water and the cement slurry in a continuous mixer to produce soil mortar. The amount of the adjustment water is calculated by subtracting the water content of the cement slurry and the water content of the soil generated on site from the total water content of the soil mortar defined by the mix design. In addition, when designing the mix design of the soil mortar, the amount of water obtained by adding the water content of the soil generated on site and the amount of the adjustment water is set to be greater than the maximum water content assumed for the soil generated on site. In addition, the transport means for transporting the on-site generated soil, the pump for pumping the adjusted water, and the pump for pumping the cement slurry are calibrated and supplied to the continuous mixer so that the on-site generated soil, the adjusted water, and the cement slurry are in a predetermined ratio.

[0006] The soil mortar manufacturing system used in the soil mortar manufacturing method includes a slurry mixer that produces cement slurry, a belt conveyor that transports on-site generated soil, a water tank that stores adjusted water, and a continuous mixer that produces soil mortar by mixing the cement slurry supplied from the slurry mixer, the on-site generated soil supplied via the belt conveyor, and the adjusted water. a transport pipe extending from the slurry mixer to the continuous mixer and pumping the cement slurry; and a water supply pipe extending from the water tank to the continuous mixer and pumping the adjusted water. It is desirable to have the following. The belt conveyor, the pump for pumping the cement slurry, and the pump for pumping the conditioned water are calibrated so that the on-site generated soil, the cement slurry, and the conditioned water are supplied to the continuous mixer at a predetermined ratio. The continuous mixer preferably includes a screw auger and a mixing paddle.

[0007] According to this soil mortar manufacturing method and soil mortar manufacturing system, the cement slurry produced according to a specified mix is ​​mixed, so unevenness is less likely to occur and the mixture can be mixed more uniformly than if cement was mixed in powder form. Therefore, soil mortar can be manufactured continuously using a continuous mixer. In addition, the amount of adjustment water is determined according to the moisture state (water content) of the soil generated on-site, so soil mortar with the desired mix can be easily manufactured. In other words, since there is no need to change the mix of the cement slurry according to the moisture state of the soil generated on-site, it is easy to respond to changes in the properties of the soil generated on-site. Effect of the Invention

[0008] According to the soil mortar manufacturing method and soil mortar manufacturing system of the present invention, it is possible to easily and efficiently manufacture soil mortar having a predetermined blend ratio. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a soil mortar production system of the present embodiment. [Diagram 2] 1 is a flowchart of a method for producing soil mortar according to the present embodiment. [Diagram 3] 13 is a graph showing the results of a demonstration experiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In this embodiment, soil mortar having desired quality is produced using on-site generated soil. A case where a soil mortar is produced will be described. Fig. 1 shows a soil mortar production system 1 used in the soil mortar production method of this embodiment. As shown in Fig. 1, the soil mortar production system 1 of this embodiment includes a slurry mixer 2, a belt conveyor 3, a first water tank 4, and a continuous mixer 5.

[0011] The slurry mixer 2 is a mixer that generates a cement slurry. The slurry mixer 2 is connected to a cement silo 21, a second water tank 22, an admixture tank 23, and a fly ash silo 24. The slurry mixer 2 mixes the cement supplied from the cement silo 21, the water supplied from the second water tank 22, the admixture tank 23, and the fly ash supplied from the fly ash silo 24 to generate a cement slurry. The cement silo 21, the second water tank 22, the admixture tank 23, and the fly ash silo 24 are each connected to the slurry mixer 2 via a supply device 25. The supply device 25 adjusts the supply amount of cement, water, admixture, or fly ash according to the blending of the cement slurry. A transport pipe 26 leading to the continuous mixer 5 is connected to the slurry mixer 2. The cement slurry produced by the slurry mixer 2 is pumped through the transport pipe 26 to the continuous mixer 5.

[0012] The belt conveyor 3 transports on-site generated soil 30 from a surplus soil storage 31 to the continuous mixer 5. On-site generated soil 30 generated by excavation work etc. is temporarily stored in the surplus soil storage 31. A hopper 32 is disposed in the surplus soil storage 31. A sieve is installed inside the hopper 32. One end of the belt conveyor 3 is disposed directly below the soil discharge outlet of the hopper 32, and the other end of the belt conveyor 3 is disposed directly above the inlet 51 of the continuous mixer 5. When the on-site generated soil 30 is supplied to the belt conveyor 3, heavy machinery such as a backhoe 33 is used to dump the on-site generated soil 30 in the soil surplus storage area 31 into a hopper 32, and the on-site generated soil 30 from which foreign objects have been removed by a sieve in the hopper 32 falls onto the belt conveyor 3. The belt conveyor 3 transports the on-site generated soil 30 supplied from the hopper 32 to the continuous mixer 5.

[0013] The first water tank 4 stores the adjusted water. The first water tank 4 is connected to the continuous mixer 5 via a water supply pipe 41. One end of the water supply pipe 41 is connected to a pump 42 provided in the first water tank 4, and the other end of the water supply pipe 41 is connected to the continuous mixer 5. The adjusted water stored in the first water tank 4 is pressure-fed to the continuous mixer 5 via the water supply pipe 41. A water meter 43 is provided in the water supply pipe 41, and measures the amount of adjusted water supplied to the continuous mixer 5. The pump 42 is controlled according to the measurement value of the water meter 43, and is configured to supply a predetermined amount of adjusted water to the continuous mixer 5.

[0014] The continuous mixer 5 produces soil mortar by mixing the cement slurry supplied from the slurry mixer 2, the on-site generated soil 30 supplied via the belt conveyor 3, and the adjusted water supplied from the first water tank 4. The continuous mixer 5 of this embodiment has a built-in screw auger and a mixing paddle. In this embodiment, the continuous mixer 5 is connected to a pressure pump vehicle 6. The soil mortar produced by the continuous mixer 5 is supplied to a mixer vehicle 61 via the pressure pump vehicle 6, and then transported to a casting site by the mixer vehicle 61.

[0015] The method for producing soil mortar according to the present embodiment will be described below. The method for producing soil mortar according to the present embodiment is shown in Fig. 2. As shown in Fig. 2, the soil mortar is produced by a preparation step S1, a measurement step S2, a calculation step S3, a cement slurry production step S4, and a slurry mortar production step S5.

[0016] In the preparation process S1, the soil mortar mix is ​​designed. The soil mortar mix is ​​designed to provide the soil mortar with the desired strength depending on the application of the soil mortar. Along with the soil mortar mix design, the cement slurry mix is ​​designed. The cement slurry mix is ​​designed to ensure that the amount of water used to produce the cement slurry is 40% or more by weight of cement, allowing the cement slurry to be pumped. The measuring step S2 is a step of measuring the moisture content of the on-site generated soil 30. The method of measuring the moisture content of the on-site generated soil 30 is not limited, but for example, it can be easily measured by measuring using a soil moisture meter at the surplus soil storage site 31. Moreover, the frequency of measuring the on-site generated soil 30 may be appropriately determined according to the season, weather, and the like.

[0017] The calculation step S3 is a step of calculating the amount of adjustment water. The amount of adjustment water is calculated by subtracting the water content of the cement slurry and the water content of the on-site generated soil 30 from the total water content of the soil mortar specified by the mix design. In addition, when designing the soil mortar mix (when designing the cement slurry mix), the total water content of the on-site generated soil 30 and the water content of the adjustment water is made to be greater than the maximum water content expected for the on-site generated soil 30. The cement slurry producing step S4 is a step of producing a cement slurry by mixing cement, fly ash, water and admixtures in a predetermined ratio.

[0018] The slurry mortar production process S5 is a process in which on-site generated soil 30, adjusted water and cement slurry are mixed in a continuous mixer 5 to produce soil mortar. On-site generated soil 30 is continuously supplied to the continuous mixer 5 via the belt conveyor 3. Adjustment water is supplied while controlling the pump 42 so that the amount of water is the amount calculated in the calculation step S3. Furthermore, a predetermined amount of cement slurry is continuously or intermittently supplied from the slurry mixer 2. That is, after calibrating the pump and belt conveyor 3, the materials are supplied to the continuous mixer 5 so that they have a predetermined ratio, thereby efficiently producing slurry mortar without repeating the cycle of measuring, mixing, and discharging. The on-site generated soil 30, adjusted water and cement slurry supplied to the continuous mixer 5 are stirred and transported by the screw auger from the inlet side (opposite the pressure pump vehicle 6) to the outlet side (the pressure pump vehicle 6 side) in the continuous mixer 5, and are stirred and mixed by the mixing paddle. The soil mortar produced by the continuous mixer 5 is supplied to the mixer vehicle 61 via the pressure pump vehicle 6 and transported to the casting site.

[0019] According to the soil mortar manufacturing method and soil mortar manufacturing system 1 of the present embodiment, the cement slurry produced by a specified mix is ​​mixed with the on-site generated soil 30, so unevenness is less likely to occur and the mixture can be mixed more uniformly than if cement was mixed in powder form. Therefore, soil mortar can be manufactured continuously using the continuous mixer 5. If soil mortar can be manufactured continuously, the supply of soil mortar will not be interrupted and efficient construction will be possible. In addition, since the amount of adjustment water is determined according to the moisture state (moisture content) of the on-site generated soil 30, soil mortar of a desired mix can be easily manufactured. In other words, since there is no need to change the mix of cement slurry according to the moisture state of the on-site generated soil 30, it is easy to respond to changes in the properties of the on-site generated soil 30. If the mix of cement slurry is changed according to the moisture content of the on-site generated soil 30, the viscosity and fluidity of the cement slurry will change, which will affect the mixability with the on-site generated soil 30. On the other hand, in this embodiment, since the mix of cement slurry is not changed and the amount of adjustment water is used to respond to changes in the moisture content of the on-site generated soil 30, the mixability of the on-site generated soil 30 and the cement slurry is unlikely to be affected. EXAMPLES

[0020] The following are test results carried out on the soil mortar manufacturing method of this embodiment. In this example, the compressive strength of the soil mortar was 10 N / mm 2 It was set to be equal to or greater than this. First, the basic mix of soil mortar is determined based on the mix study conducted in the laboratory. The basic mix is ​​shown in Table 1.

[0021] [Table 1]

[0022] Next, the amount of adjusting water is set based on the basic mix in Table 1, and the mix for the example is set. Table 2 shows the mix for the example.

[0023] [Table 2]

[0024] The on-site mix is ​​set based on the mix in Table 2. At this time, the mix of soil mortar is kept constant, and 3 Winning combination (1m 3 Mass per m 3 The on-site mix is ​​shown in Table 3. The generated soil in Table 3 is 3It contains 119 kg of water per serving.

[0025] [Table 3]

[0026] The soil mortar is manufactured on-site according to the mix ratio in Table 3. When manufacturing the soil mortar, the production speed is set to 40 m / s, taking into consideration the casting speed and the capacity of the machines such as the continuous mixer 5. 3 Depending on the production speed, the generated soil was supplied by the belt conveyor 3 at 965 kg / min, the cement slurry was supplied by the pump at 246 L / min, and the adjustment water was supplied by the pump 42 at 23 L / min. The strength of the manufactured soil mortar was confirmed on the seventh day after it was used as material. The strength of each specimen was confirmed for specimen A, which was taken immediately after production at the plant, and specimen B, which was taken after being transported to a designated location. Figure 3 shows the strength of the soil mortar and the strength of the indoor mix test. As shown in Figure 3, both specimens A and B had a required strength of 10N / mm 2 It was also confirmed that the concrete exhibited strength equivalent to that of the indoor mix test results (solid line C).

[0027] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each of the above-described components can be appropriately modified without departing from the spirit of the present invention. For example, the materials and the composition of the cement slurry are not limited and may be appropriately determined. For example, in the above embodiment, fly ash is mixed when producing the cement slurry, but fly ash may be mixed as needed. Furthermore, there are no limitations on the admixtures to be mixed in when producing the cement slurry, and for example, a water reducing agent, a high performance water reducing agent, a fluidizing agent, an air foaming agent, etc. may be used. The configuration of the continuous mixer 5 is not limited to that shown in the above embodiment, and may be, for example, one having only a built-in screw auger. [Explanation of symbols]

[0028] 1. Soil mortar production system 2. Slurry Mixer 3. Conveyor belt 4 First Water Tank (Water Tank) 5 Continuous Mixer S2 measurement process S3 calculation process S4 Cement slurry production process S5 Soil mortar manufacturing process

Claims

1. Measuring the moisture content of the on-site generated soil; A step of calculating the amount of adjustment water; mixing cement, water and admixtures according to a predefined ratio to produce a cement slurry; A method for producing soil mortar comprising: a step of mixing the on-site generated soil, the adjusted water, and the cement slurry by a continuous mixer to produce soil mortar; The amount of the adjustment water is calculated by subtracting the water content of the cement slurry and the water content of the on-site generated soil from the total water content of the soil mortar specified by the mix design, A method for producing soil mortar, characterized in that a transport means for transporting the on-site generated soil, a pump for pumping the adjusted water, and a pump for pumping the cement slurry are calibrated and then supplied to the continuous mixer so that the on-site generated soil, the adjusted water, and the cement slurry are in a predetermined ratio.

2. a slurry mixer for producing a cement slurry; A conveyor belt for transporting on-site generated soil, A water tank for storing regulated water; A continuous mixer that mixes the cement slurry supplied from the slurry mixer, the on-site generated soil supplied via the belt conveyor, and the adjusted water to produce soil mortar; a transport pipe extending from the slurry mixer to the continuous mixer for pumping the cement slurry; A soil mortar manufacturing system comprising: a water supply pipe from the water tank to the continuous mixer for pumping the adjusted water; A soil mortar manufacturing system, characterized in that the belt conveyor, the pump for pumping the cement slurry, and the pump for pumping the adjusted water are calibrated so that the on-site generated soil, the cement slurry, and the adjusted water are supplied to the continuous mixer at a predetermined ratio.

3. The soil mortar manufacturing system according to claim 2, wherein the continuous mixer is equipped with a screw auger and a mixing paddle.

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