Grouting slurry based on shield muck and industrial solid waste cementing material and preparation method

Abstract

The invention discloses grouting slurry based on shield muck and an industrial solid waste cementing material and a preparation method, and belongs to the field of tunnel construction, the industrial solid waste cementing material provided by the invention is used for replacing Portland cement, energy conservation and emission reduction are achieved, and meanwhile, exploitation of non-renewable resources such as high-quality clay and limestone is reduced; in addition, due to hydration reaction of the carbide slag and the blast furnace slag, the strength of the synchronous slurry is greatly improved. The efficient grouting slurry is obtained from waste raw materials, the production cost of the grouting slurry is reduced, and the requirement of the grouting slurry for strength can be met.

Description

Technical Field

[0001] The invention belongs to the field of tunnel construction, and in particular relates to a grouting slurry based on shield slag and industrial solid waste gelling material and a preparation method thereof. Background Art

[0002] Common methods of tunnel construction include shallow buried tunneling, shield tunneling, TBM, pipe jacking, drilling and blasting, open cut and immersed tube construction, etc. Among them, shield tunneling is the main method for subway construction. It has the advantages of small impact on the environment, construction is not affected by depth and thickness of cover soil, easy construction management, small amount of earthwork, and construction is not affected by climate. It is particularly suitable for the construction of urban subway tunnels under complex geological conditions with complicated buildings, public facilities and transportation systems. It is widely used in tunnel construction, but it will produce a lot of shield slag during the construction process, especially when using slurry balance shield construction, it will also produce a lot of shield waste mud.

[0003] Waste mud and slag from shield tunneling refers to the waste that is transported to the ground after the soil produced by the shield cutter head excavating the stratum is mixed with materials such as mud. Among them, the waste mud and slag from earth pressure shield tunneling has a low water content and is in the state of sand and clay. In some special cases, earth pressure balance shield tunneling will also discharge products similar to mud; while the waste mud and slag from slurry shield tunneling is separated into mud and slag after being treated by the mud-water separation system. Part of the mud enters the mud circulation system for reuse, and the excess mud becomes waste mud. The slag can be divided into waste clay and waste sand according to the different excavation strata. At present, waste mud from shield tunneling is usually dehydrated by filter press and converted into mud cake, and then transferred and placed together with shield slag by transport vehicles. This treatment method not only has high transportation costs, but also occupies a lot of land. It only transfers the waste mud and slag in space without resource utilization, which is a serious waste of mud and slag resources. Therefore, it is of great practical significance to study the resource utilization of waste mud and slag from shield tunneling.

[0004] The existing shield slag resource utilization is to prepare synchronous grouting materials, and the cementitious material is mainly cement solidified by slag. However, the production of 1 ton of silicate cement will produce about 0.9 tons of carbon dioxide greenhouse gas, causing a serious greenhouse effect, which is inconsistent with my country's environmental protection and low-carbon policies. Therefore, new means of resource utilization of shield slag are needed.

[0005] CN116639893A discloses a cementitious material for synchronous grouting and a synchronous grouting material and a preparation method. The scheme uses cementitious material A: 20-30 parts of slag micropowder, 20-40 parts of high-calcium fly ash, 20-30 parts of ultrafine steel slag powder, 7-15 parts of by-product gypsum, 5-8 parts of carbide slag, and 3-5 parts of ultrafine silica fume; modified shield mud B: 50-90 parts of shield slag, 0.1-1.2 parts of consistency regulator, 0.1-1.2 parts of dispersant, 0.5-1.5 parts of defoamer, and 10-50 parts of water; high-performance composite activator C: 30-50 parts of sodium silicate, 8-15 parts of caustic soda, 5-15 parts of soda ash, 30-50 parts of sodium sulfate, and 0-100 parts of water to prepare synchronous grouting slurry. This scheme can achieve precise control from tens of seconds to several hours through formula adjustment, and the performance after hardening can fully meet or even exceed the mechanical properties of traditional cement mortar grouting materials. However, this scheme also has some shortcomings: (1) The cementitious material A used in this scheme has many components, and the material acquisition and transportation process is cumbersome. At the same time, the dosage of cementitious material A is relatively high, which is not conducive to the control of construction costs. In the case where the slag is obtained from clay strata, less than half of the amount of cementitious agent is required to obtain similar compressive strength; (2) The modified shield mud B used in this scheme requires the shield slag to be improved and treated by adding a modifier. The procedure is cumbersome and not conducive to faster construction; (3) The high-performance composite activator C used in this scheme has a large number of strongly alkaline components. On the one hand, the price is relatively high, and on the other hand, it has certain physiological hazards to operators and has adverse effects on the environment. (4) The comprehensive cost of this scheme is about 350 yuan / m 3 Among its high-performance admixtures, the price of sodium hydroxide is 2,800 yuan / ton, the price of sodium silicate is 3,400 yuan / ton, the price of soda ash is 1,020 yuan / ton, and the price of sodium sulfate is 650 yuan / ton. The high prices are not conducive to mass use. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a grouting slurry based on shield slag and industrial solid waste cementitious materials.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for preparing grouting slurry based on shield slag and industrial solid waste cementitious materials, characterized in that: comprising:

[0010] Dry-mixing carbide slag powder and blast furnace slag powder to obtain an industrial solid waste gel material;

[0011] Mixing water and shield slag powder to obtain slag slurry;

[0012] The industrial solid waste gel material is added into the slag slurry and stirred evenly to obtain the grouting slurry.

[0013] As a preferred embodiment of the preparation method of the present invention, the mass ratio of the carbide slag powder to the blast furnace slag powder is 1:4-9.

[0014] As a preferred embodiment of the preparation method of the present invention, the specific surface area of ​​the carbide slag powder is 20 to 27 m 2 / g, and the median particle size is 30-150μm.

[0015] As a preferred embodiment of the preparation method of the present invention, the specific surface area of ​​the blast furnace slag is 1.5 to 3.0 m 2 / g, and the median particle size is 5 to 50 μm.

[0016] As a preferred embodiment of the preparation method of the present invention, the usage ratio of water to shield slag powder is 1 to 1.5:1.

[0017] As a preferred embodiment of the preparation method of the present invention, the mass ratio of the industrial solid waste gel material to the slag slurry is 1:10-9.

[0018] Another object of the present invention is to overcome the deficiencies in the prior art and provide a grouting slurry.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a grouting slurry for use in synchronous grouting of a tunnel shield.

[0020] As a preferred solution of the application of the present invention, the 3d compressive strength of the synchronous grouting material reaches above 0.5 MPa.

[0021] As a preferred solution of the application of the present invention, the 28d compressive strength of the synchronous grouting material reaches above 2.5 MPa.

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention uses the slag produced by shield excavation as fine aggregate of grouting material, thereby reducing the land occupation and environmental pollution problems caused by the transportation and stacking of slag.

[0024] (2) The industrial solid waste cementitious material provided by the present invention is used to replace silicate cement, thereby achieving energy conservation and emission reduction, while reducing the exploitation of high-quality clay and limestone non-renewable resources.

[0025] (3) The hydration reaction of carbide slag and blast furnace slag in the present invention greatly improves the strength of the synchronous slurry. The present invention obtains a highly efficient grouting slurry using waste raw materials, reduces the production cost of the grouting slurry and can meet the strength requirements of the grouting slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0027] Figure 1 The present invention is a flow chart of the grouting slurry and preparation method based on shield slag and industrial solid waste cementitious materials.

[0028] Figure 2 This is a 5k-fold magnified SEM image of the synchronous slurry molding obtained in Example 4, which was cured for 28 days in a standard curing box at (20±2)°C and a relative humidity of more than 95%.

[0029] Figure 3 This is a SEM image of Example 4 magnified 10k times.

[0030] Figure 4 These are SEM images of different locations of the sample in Example 4 magnified 5k times. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0034] The raw materials used in the present invention are: carbide slag slurry obtained from Taicang Jinyang Gas Co., Ltd., which is the waste material of preparing acetylene gas from calcium carbide; blast furnace slag obtained from Jiangsu Sugang Group Co., Ltd., which is a by-product of blast furnace steelmaking.

[0035] Instruments used in the embodiments of the present invention: concrete curing box 60B; 70.7*70.7*70.7 triple plastic mortar test mold; SYJ-10 cement mortar mixer; NLD-3 electric jumping table; SC-145 cement mortar consistency meter; Nanjing Techao Technology Co., Ltd.-full-automatic unconfined pressure instrument.

[0036] Figure 1 The present invention provides a flow chart of a method for preparing a grouting slurry based on shield slag and industrial solid waste cementitious materials, which specifically comprises mixing carbide slag and blast furnace slag, and stirring to obtain an industrial solid waste cementitious material; adding water and slag powder into a mixer according to a certain water-cement ratio, and mixing them evenly to obtain slag slurry; adding the industrial solid waste cementitious material into the slag slurry and stirring evenly to obtain a grouting slurry based on shield slag and industrial solid waste cementitious materials.

[0037] The chemical composition of the carbide slag used in the embodiment of the present invention is shown in Table 1. The specific surface area of ​​the carbide slag is 22.76 m 2 / g, the medium particle size is preferably 80 μm; the specific surface area of ​​the blast furnace slag is 2.67 m 2 / g, and the median particle size is 25μm.

[0038] Table 1 Statistics of chemical composition of shield slag

[0039]

[0040]

[0041] Table 2 Statistics of chemical composition of blast furnace slag

[0042]

[0043] Table 3 Statistics of chemical composition of carbide slag

[0044]

[0045] Example 1

[0046] This embodiment is the preparation of shield slag, including the following steps:

[0047] (1) Allow the shield excavation soil to dry naturally for 7 to 14 days to remove moisture from the excavation soil;

[0048] (2) Pass the sun-dried soil through a 4-20 mm sieve to remove sand and gravel particles in the soil;

[0049] (3) The sieved slag is added to a grinder for mechanical grinding to 0.05-0.5 mm to obtain slag powder.

[0050] Example 2

[0051] The present embodiment is the preparation of carbide slag, comprising the following steps:

[0052] (1) Spread fresh carbide slag slurry on a tray and place it in a drying oven for drying at a temperature of 80 to 100°C for 6 to 10 hours;

[0053] (2) Using a jaw crusher to preliminarily crush the dried carbide slag, and then passing it through a 4-20 mm sieve;

[0054] (3) Add the sieved calcium carbide slag into a grinder for mechanical grinding until all of it passes through a 0.05-0.5 mm sieve.

[0055] Example 3

[0056] This embodiment is the preparation of blast furnace slag, comprising the following steps:

[0057] (1) Raw materials such as slag are transported into the factory by loading trucks, and then sent to the slag shed for storage and drying via unloading hoppers and belt conveyors;

[0058] (2) The raw materials are subjected to multiple iron removal operations in the iron removal device, and then are quantitatively and continuously fed into the vertical mill for grinding through air-locking feeding equipment such as screw conveyors;

[0059] (3) The ground powder is selected by a powder selector with the help of hot air provided by a hot air furnace and is dried at the same time;

[0060] (4) The unqualified ore particles fall from the cone bucket back to the grinding disc for re-grinding, and the qualified ore powder is transported to the dust collector after being discharged from the mill along with the air flow, and then transported to the finished product warehouse for storage through the air conveying chute and elevator.

[0061] Example 4

[0062] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0063] (1) Take 6g of calcium carbide slag and ordinary blast furnace slag (specific surface area of ​​1.5824m 2 / g) 54 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0064] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0065] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0066] Figure 2 This is the SEM image of the synchronous grouting material prepared in this embodiment, which was cured for 28 days in a standard curing box at (20±2)°C and a relative humidity of more than 95%. It can be seen that after 28 days of curing, calcium feldspar is generated in the sample, which significantly improves the strength.

[0067] Figure 3 , 4 The SEM images at different magnifications and positions of this embodiment show that after 28 days of curing, hydrated calcium silicate gel and calcium aluminate are generated in the sample, which significantly improves the strength.

[0068] Example 5

[0069] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0070] (1) 12 g of carbide slag and 48 g of blast furnace slag with ordinary particle size are mixed and stirred to obtain an industrial solid waste gelling material;

[0071] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0072] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0073] Example 6

[0074] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0075] (1) Take 6g of calcium carbide slag and 600-mesh blast furnace slag (specific surface area of ​​2.1744m 2 / g) 54 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0076] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0077] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0078] Example 7

[0079] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0080] (1) Take 6g of calcium carbide slag and 800-mesh blast furnace slag (specific surface area of ​​2.1744m 2 / g) 54 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0081] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0082] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0083] Example 8

[0084] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0085] (1) Take 12g of calcium carbide slag and 800-mesh blast furnace slag (specific surface area of ​​2.1744m 2 / g) 48 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0086] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0087] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0088] Example 9

[0089] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0090] (1) Take 14.4 g of calcium carbide slag and 800 mesh blast furnace slag (specific surface area of ​​2.1744 m 2 / g) 57.6 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0091] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0092] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0093] Example 10

[0094] This embodiment is the preparation of synchronous grouting material, comprising the following steps:

[0095] (1) Take 18g of calcium carbide slag and 800-mesh blast furnace slag (specific surface area of ​​2.1744m 2 / g) 72 g, and after mixing the two, stirring to obtain an industrial solid waste gelling material;

[0096] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0097] (3) Adding the cementitious material obtained in step (1) to the slag slurry obtained in step (2) and stirring the mixture evenly to obtain a synchronous grouting material.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 4 is that the cementitious material adopts PO 42.5 ordinary Portland cement.

[0100] (1) Take 60g of cement as the cementitious material;

[0101] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0102] (3) Adding PO 42.5 ordinary Portland cement to the slag slurry obtained in step (2) and stirring evenly to obtain a synchronous grouting material.

[0103] Comparative Example 2

[0104] The difference between this comparative example and Example 4 is that the cementitious material adopts PO 42.5 ordinary Portland cement.

[0105] (1) Take 90g of cement as a cementitious material;

[0106] (2) 400 g of shield slag powder and 200 g of water were added into a mixer and mixed evenly to obtain slag slurry;

[0107] (3) Adding PO 42.5 ordinary Portland cement to the slag slurry obtained in step (2) and stirring evenly to obtain a synchronous grouting material.

[0108] Comparative Example 3

[0109] The difference between this comparative example and Example 4 is that in step (1), the mass ratio of carbide slag to blast furnace slag is replaced by 1:10, and the remaining steps are the same as those in Example 4 to obtain a synchronous grouting material.

[0110] Comparative Example 4

[0111] The difference between this comparative example and Example 4 is that in step (1), the mass ratio of carbide slag to blast furnace slag is replaced by 3:7, and the remaining steps are the same as Example 4 to obtain synchronous grouting material.

[0112] Embodiment 11

[0113] This embodiment is to test the performance of the prepared synchronous grouting material, and the test results are shown in Table 4.

[0114] Among them, the consistency test method: the consistency refers to the depth of the cone falling freely into the mortar. The consistency of the slurry refers to the "Standard for Test Methods for Basic Properties of Building Mortar" (JGJ / T70-2009) and is measured using a mortar consistency meter.

[0115] Slump test method: The slump of mortar indicates the maximum diameter of the mortar on the plane. The slump of the slurry is measured with reference to the "Method for Determination of Fluidity of Cement Mortar" (GB / T2419-2005). The truncated cone circular mold used has an upper inner diameter of 70mm, a lower inner diameter of 100mm, and a height of 60mm. Pour the prepared mortar into the mold, and after jumping on the jumping table 25 times, measure the maximum diameter of the slurry.

[0116] Test method for water seepage rate: solid particles in mortar settle, free water floats, and the unit volume of water formed after solid-liquid separation is the water seepage rate of mortar. If the water seepage rate is too large, the mortar is easy to segregate and cause pipe blockage. The slurry water seepage rate refers to the "Technical Specifications for the Application of Synchronous Grouting Materials in Shield Tunneling" (T / CECS 563-2018). Pour the synchronous slurry into a measuring cylinder and measure the water seepage surface scale value and the slurry surface scale value after standing for 3 hours.

[0117] Test method for unconfined compressive strength: The unconfined compressive strength of the specimen is measured using an unconfined pressure instrument with reference to the "Standard for Test Methods for Basic Properties of Building Mortar" (JGJ / T70-2009).

[0118] Table 4 Performance test statistics of synchronous grouting materials

[0119]

[0120] As can be seen from Table 4 above, the 28d strength of Example 4, Example 5, Example 6, Example 7, Example 8, Example 9, and Example 10 is greater than that of the comparative example, and the fluidity and stability indicators are similar to those of the comparative example. Comparing Example 4 and Example 5, it can be seen that increasing the proportion of carbide slag in the cementitious material can improve the compressive strength, because the increase of carbide slag increases the alkalinity of the slurry, thereby accelerating the hydration rate and increasing the degree of hydration, and generating more hydration products. Comparing Example 7, Example 8, Example 9, and Example 10, it can be seen that increasing the proportion of cementitious materials can improve the compressive strength of the material. Comparing Example 4 with Example 6 and Example 7, it can be seen that the strength of Example 6 and Example 7 is higher than that of Example 1, and the blast furnace slag with a smaller particle size (i.e., a larger specific surface area) makes the hydration reaction more sufficient, so that the density of the material is increased and the porosity is reduced, thereby improving the mechanical properties of the synchronous slurry stone body. Comparing the examples with the comparative examples, it can be seen that the strength of the slurry stone body using industrial solid waste cementitious materials is much higher than that of the slurry stone body using the same amount of cement. In addition, the raw material price required for the present invention is: S95 slag powder is 350 yuan / ton, and calcium carbide slag is obtained from acetylene plant, which is solid waste and has almost 0 cost. According to the slurry ratio of the present invention, the comprehensive cost is 48 yuan / m 3 , the cost is extremely low.

[0121] In summary, the present invention obtains efficient cementitious materials from solid waste, reduces the production cost of the materials and can meet the strength requirements of the synchronous slurry, while solving the disposal problem of waste carbide slag and blast furnace slag, saving energy and reducing emissions, and turning waste into treasure.

[0122] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for preparing grouting slurry based on shield slag and industrial solid waste cementitious materials, characterized in that: include, Dry-mixing carbide slag powder and blast furnace slag powder to obtain an industrial solid waste gel material; Mixing water and shield slag powder to obtain slag slurry; The industrial solid waste gel material is added into the slag slurry and stirred evenly to obtain the grouting slurry.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the carbide slag powder to the blast furnace slag powder is 1:4-9.

3. The preparation method according to claim 1, characterized in that: The specific surface area of ​​the carbide slag powder is 20 to 27 m 2 / g, and the median particle size is 30-150μm.

4. The preparation method according to claim 1, characterized in that: The specific surface area of ​​the blast furnace slag is 1.5 to 3.0 m 2 / g, and the median particle size is 5 to 50 μm.

5. The preparation method according to claim 1, characterized in that: The usage ratio of water to shield slag powder is 1 to 1.5:

1.

6. The preparation method according to claim 1, characterized in that: The mass ratio of the industrial solid waste gel material to the slag slurry is 1:10-9.

7. Grouting slurry obtained by the preparation method according to any one of claims 1 to 6.

8. Application of the grouting slurry as claimed in claim 7 in synchronous grouting of tunnel shield.

9. The use according to claim 8, characterized in that: The 3d compressive strength of the synchronous grouting material reaches above 0.5 MPa.

10. The use according to claim 9, characterized in that: The 28d compressive strength of the synchronous grouting materials reaches above 2.5MPa.

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