An in-situ shield muck flow state filling material, a preparation method and application thereof

Abstract

The present application relates to a kind of original shield muck flow state filling material and its preparation method and application, the filling material includes original shield muck and solidified material, solidified material includes alkali excitation cementing material 30%-80%, cement 10%-40%, stone powder 1%-10%, gypsum 5%-15% and flowability control agent 1%-5%, flowability control agent includes sodium metaaluminate and / or calcium chloride, the mass of the solidified material is 0-15% of the filling material, the present application also includes the preparation method of flow state filling material, by adding a certain amount of flowability control agent finally, the flowability of high water content, high flowability shield muck filling material is reduced in time, can avoid filling loss under the premise of not affecting solidified strength.The 7d strength of the original shield muck flow state filling material of the present application reaches 0.3MPa after solidification, meets backfilling requirement, has important social and economic benefits and environmental benefits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building material and solid waste treatment, and particularly relates to a flowable filling material of original shield muck and a preparation method and application thereof. BACKGROUND

[0002] In the process of shield tunneling, in order to avoid cutter wear and mud cake phenomenon, ensure smooth tunneling and muck discharge, it is necessary to add foaming agent, high molecular polymer and the like to improve the muck, so that the shield muck has good fluidity. How to dispose of a large amount of shield muck will be a problem that cannot be avoided in subway construction. At the same time, China's urbanization is still in a rapid development stage. For example, the base trench, hole or other narrow space of pipe gallery, building, rail transit engineering and the like, road embankment, and the back of traffic engineering and the like need to be backfilled. If the original shield muck is prepared into flowable filling material in cooperation with industrial solid waste and used in these parts, the shield muck can be treated and utilized on a large scale, the production cost can be reduced, the added value of the shield muck can be improved, the waste can be turned into treasure, and remarkable economic benefit, environmental benefit and social benefit can be achieved.

[0003] In addition, the above-mentioned parts have large volume and irregular shape, and the fluidity of the original shield muck flowable filling material is large. If the fluidity is not timely controlled, the filling material is easy to be wasted. Therefore, how to change the fluidity of the shield muck flowable filling material in time on the basis of ensuring the solidification strength is the key to the preparation method. SUMMARY

[0004] The present application is aimed at the problems that the shield muck has high water content, large viscosity, low bearing capacity, is difficult to dewater and screen, and further leads to the difficulty in disposal and resource utilization of the shield muck. The high-fluidity flowable filling material is prepared by adding extra water to regulate into mud and directly solidifying. The shield muck can be disposed on a large scale while the added value thereof is improved, and the purpose of full resource utilization is achieved. The fluidity of the shield muck flowable filling material is changed in time on the basis of ensuring the solidification strength of the flowable filling material, the fluidity of the filling material is effectively controlled, and the waste of the filling material is avoided.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] An original shield muck flowable filling material, comprising original shield muck and solidifying material, the solidifying material comprises raw materials in the following mass percentage: alkali-activated cementitious material 30%-80%, cement 10%-40%, stone powder 1%-10%, gypsum 5%-15% and fluidity regulator 1%-5%;

[0007] The fluidity regulator comprises sodium metaaluminate and / or calcium chloride.

[0008] The solidified material is 0-15% of the mass of the filler.

[0009] Preferably, the as-is shield muck is the as-is muck that is transported into the muck chamber by screw conveyors, belt conveyors, rail muck cars or pumped into the ground muck pool after the earth in front of the cutter head of a shield machine is cut.

[0010] Preferably, the as-is shield muck is one or more of earth pressure balance shield muck or slurry balance shield muck.

[0011] Preferably, the as-is shield muck has an initial water content greater than 30%.

[0012] Preferably, the alkali-activated cementitious material is composed of the following mass percentage raw materials: cementitious component 70%-90% and alkali activator 10%-30%.

[0013] Preferably, the cementitious component is one or more of blast furnace slag, fly ash, silica fume, steel slag, phosphorous slag.

[0014] Further, the fineness of the cementitious component is greater than 200 mesh.

[0015] Preferably, the alkali activator is one or more of quicklime, sodium carbonate, sodium silicate, sodium hydroxide.

[0016] Preferably, the quicklime has a calcium content greater than 75% and a fineness greater than 100 mesh.

[0017] Preferably, the sodium carbonate is in powder form and has a fineness greater than 100 mesh.

[0018] Preferably, the sodium silicate is in powder form, has a modulus of 2.0-3.2 and a fineness greater than 100 mesh.

[0019] Preferably, the sodium hydroxide is solid flaky analytical pure with a purity greater than 99%.

[0020] Preferably, the stone powder is one or more of natural stone powder, construction waste recycled micro powder and has a fineness greater than 200 mesh.

[0021] Preferably, the gypsum is one or more of natural gypsum, desulfurization gypsum.

[0022] Preferably, the sodium metaaluminate is in powder form and has a fineness greater than 100 mesh.

[0023] Preferably, the calcium chloride is in solid granular or powder form.

[0024] Preferably, the cement is Portland cement.

[0025] Further, the preparation method of the original shield muck flowable filling material described above comprises the following steps:

[0026] (1) The original shield muck is mixed with water to form a high-fluidity slurry with a water content greater than 60%, to obtain original shield muck slurry S1;

[0027] (2) A mixture of alkali-activated cementitious material, cement, stone powder and gypsum is added to the high-fluidity shield muck slurry S1, and mixed and stirred uniformly to obtain a mixture S2;

[0028] (3) A fluidity regulating agent is added to the mixture S2, and mixed and stirred uniformly to obtain the final shield muck flowable filling material S3.

[0029] Preferably, the original shield muck flowable filling material described in the present application can be applied to backfilling of foundation trenches, holes or other narrow spaces in pipe galleries, buildings, rail transit engineering and the like.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] The present application aims to solve the problems of high water content, high viscosity, low bearing capacity and difficulty in dewatering and screening of shield muck. By mixing with water to form a slurry and adding solidifying materials to prepare a high-fluidity flowable filling material, the shield muck can be large-scale accommodated while its added value is improved. No waste water, waste residue or mud cake is generated in the whole process, and the purpose of full resource utilization is achieved. In the present application, the alkali-activated cementitious material, cement, stone powder, gypsum and fluidity regulating agent are compounded. After the original shield muck slurry is mixed with the cementitious material, the alkali activator dissolves in the original shield muck slurry to form a strong alkali environment, which activates the Si-O and Al-O bonds in the glass body of the cementitious component, dissolves [SiO4] and [AlO4] tetrahedrons and diffuses to the surrounding, adsorbs on the surface of the shield muck slurry particles, generates calcium silicate hydrate, calcium aluminate hydrate and calcium silicate-aluminate hydrate gel, and forms a muck stone body. The stone powder plays a role in defoaming and improves the compactness of the filling material, and the gypsum can absorb part of the free water. Finally, sodium metaaluminate and / or calcium chloride are added as fluidity regulating agents, which are easily dissolved in water and have strong hygroscopicity, to reduce the free water content in the flowable filling material and effectively reduce its fluidity. In addition, the aluminate ion is still alkaline after being hydrated into hydroxyl ion, and the addition amount of sodium metaaluminate is not less than that of calcium chloride, which does not affect the solidification effect of the alkali-activated cementitious material system. The present application reduces the fluidity of the shield muck flowable filling material in time on the basis of ensuring the solidification strength, thereby avoiding material waste.

[0032] The application is based on alkali activation principle and technology, and raw shield muck is prepared into flowable filling material together with industrial by-products, etc., to realize "waste treatment with waste", and the high water content raw shield muck is adjusted into a slurry state with a water content of more than 60% by adding extra water, which greatly improves the fluidity of the shield muck slurry. Compared with direct stirring of raw shield muck, the mixing and stirring of the slurry state are more sufficient and uniform. For high-viscosity muck, the usual method is to add a dispersing agent to achieve the effect of dispersion and uniform mixing, which has the disadvantages of high cost, environmental pollution and influence on curing effect. The application greatly improves the fluidity of the shield muck slurry by adding extra water, and effectively solves the problem of excessive fluidity of the filling material by adding a fluidity regulator at the end, avoiding the use of dispersing agents.

[0033] The raw shield muck slurry in the flowable filling material has a large amount of mixing and high curing strength, and can be widely applied to backfilling of foundation trenches, holes or other narrow spaces, can large-scale absorb shield muck, improve the added value thereof, and has important social and economic benefits and environmental benefits. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a flowability comparison chart of the flowable filling material of raw shield muck of the specific embodiment 1 and the comparative example 1 of the application. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application will be described in detail below. In the following description, a large number of specific details are set forth in order to fully understand the application. However, the application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the concept of the application, so the application is not limited to the specific embodiments disclosed below.

[0036] Generally, the initial water content of the slurry balance shield muck is high, and the flowable filling material can be directly prepared. The initial water content of the earth pressure balance shield muck is different from that of the slurry balance shield muck, and is usually between 30%-50%, mainly in the soft plastic and plastic state, in the "paste" state, with certain fluidity, and great differences in apparent density, water content, porosity, particle size distribution and permeability. It is extremely difficult to dehydrate and sieve by traditional methods. For example, mechanical or physical dehydration has the problems of low efficiency, high energy consumption and high cost, and filter presses and centrifuges are suitable for cases without coarse particles. The soil or vacuum preloading efficiency is very low due to the small permeability of the earth pressure balance shield muck. The efficiency of the drying method is low and the cost is very high. Because the earth pressure balance shield muck is in a paste state, it is found that the muck will shrink into a ball during natural airing or drying, and the outside is dry while the inside is still wet. Therefore, there is no effective method for dehydrating the earth pressure balance shield muck at present.

[0037] The earth pressure balance shield slurry separation is also difficult, because the shield slurry has high mud content and high viscosity, several times of water needs to be added to achieve effective separation, and the hole will be blocked, and the screening efficiency is very low. In addition, the shield slurry contains a foaming agent, which will produce a lot of foam during the vibration screening process, and the clay particles in the foam will adhere to the surface of the sand and gravel particles, resulting in a decrease in quality.

[0038] The present embodiment proposes a state shield slurry flow filling material, which comprises a state shield slurry and a solidified material, and the solidified material comprises the following raw materials in mass percentage: 30%-80% of alkali-activated cementitious material, 10%-40% of cement, 1%-10% of stone powder, 5%-15% of gypsum and 1%-5% of fluidity regulator; wherein the fluidity regulator comprises sodium aluminate and / or calcium chloride; the mass of the solidified material is 0-15% of the filling material.

[0039] The state shield slurry is the state slurry in the earth pressure balance shield machine, which is cut by the cutter head and then enters the soil bin, and is transported by the screw conveyor, belt conveyor, rail slurry car or pumped to the ground slurry pool without dehydration and screening treatment.

[0040] The state slurry is one or more of the earth pressure balance shield slurry or the slurry of the slurry balance shield.

[0041] The alkali-activated cementitious material is composed of the following raw materials in mass percentage: 70%-90% of cementitious component and 10%-30% of alkali activator.

[0042] The cementitious component is one or more of blast furnace slag, fly ash, silica fume, steel slag and phosphorous slag.

[0043] The fineness of the cementitious component is more than 200 mesh.

[0044] The alkali activator in the alkali-activated cementitious material is one or more of quicklime, sodium carbonate, sodium silicate and sodium hydroxide.

[0045] The quicklime has a calcium content of more than 75% and a fineness of more than 100 mesh.

[0046] The sodium carbonate is in powder form and has a fineness of more than 100 mesh.

[0047] The sodium silicate is in powder form, has a modulus of 2.0-3.2 and a fineness of more than 100 mesh.

[0048] The sodium hydroxide is solid flaky analytical pure, with a purity of more than 99%.

[0049] The stone powder is one or more of natural stone powder and construction waste recycled micro powder, and has a fineness of more than 200 mesh.

[0050] The gypsum is one or more of natural gypsum and desulfurization gypsum.

[0051] The sodium metaaluminate is in powder form and has a fineness greater than 100 mesh.

[0052] The calcium chloride is in solid granular or powder form.

[0053] The raw shield muck flowable filling material and the preparation method thereof provided in the specific embodiment further include flowability regulation of the raw shield muck flowable filling material, i.e., research on the preparation method of the raw shield muck flowable filling material.

[0054] The raw shield muck flowable filling material is prepared by using the slag-cement composite solidification material, and the effects of sodium metaaluminate, sodium sulfate, aluminum sulfate, polyaluminum chloride, calcium chloride and polyacrylamide on the flowability of the raw shield muck flowable filling material are investigated.

[0055] The ratio of the slag and the cement is 6:4, the mixing amount in the shield muck flowable filling material is 10%, the water content of the raw shield muck slurry is 115%, the slag-cement composite solidification material is added into the raw shield muck slurry and mixed and stirred uniformly, and according to GB / T2419-2005 "Cement mortar flowability determination method", the flowability of the shield muck flowable filling material is measured to be 27 cm.

[0056] Meanwhile, 2.5% of sodium metaaluminate, sodium sulfate, aluminum sulfate, polyaluminum chloride, calcium chloride and polyacrylamide are respectively added into the filling material for comparison, and the flowabilities are measured to be 24.5 cm, 27 cm, 27 cm, 27 cm, 25.5 cm and 27 cm respectively. It can be seen that sodium metaaluminate and calcium chloride can effectively reduce the flowability of the shield muck flowable filling material.

[0057] In addition, it is found that the addition of sodium metaaluminate, calcium chloride or the mixture of the two alone does not reduce the solidification strength of the flowable filling material.

[0058] Therefore, sodium metaaluminate and / or calcium chloride are selected as the flowability regulator.

[0059] According to the specific embodiment, a preparation method of a raw shield muck flowable filling material is provided, which includes the following steps:

[0060] (1) The raw shield muck is mixed with water to prepare a high-flowability slurry with a water content greater than 60% to obtain raw shield muck slurry S1;

[0061] (2) A mixture of alkali-activated cementitious material, cement, stone powder and gypsum is added into the high-flowability shield muck slurry S1, and mixed and stirred uniformly to obtain a mixture S2;

[0062] (3) adding the flowability regulator into the mixture S2, mixing and stirring uniformly to obtain the final shield muck flowable filling S3.

[0063] The present embodiment also includes the in-situ shield muck flowable filling prepared by the above preparation method.

[0064] The following further lists relevant examples for detailed description. The in-situ shield muck in the following examples is taken from the fully weathered slate shield muck material of a certain section of Changsha Metro Line 6, and the prepared flowable filling can be applied to the backfilling of trench, hole or other narrow space in pipe gallery, building, rail transit engineering, etc.

[0065] Example 1

[0066] An in-situ shield muck flowable filling, comprising in-situ shield muck and solidifying material, wherein the solidifying material is composed of the following raw materials in mass percentage: blast furnace slag 40%, fly ash 10%, quicklime 5%, sodium carbonate 5%, sodium silicate 5%, portland cement 16%, natural stone powder 5%, desulfurization gypsum 10%, sodium metaaluminate 3%, calcium chloride 1%. The dosage of the solidifying material in the in-situ shield muck flowable filling is 12%, and the preparation method of the flowable filling comprises the following steps:

[0067] (1) adding water to the in-situ shield muck to prepare a high-flowability mud-like material with a water content of 115% to obtain in-situ shield muck mud S1;

[0068] (2) adding a mixture of blast furnace slag, fly ash, quicklime, sodium carbonate, sodium silicate, portland cement, natural stone powder and desulfurization gypsum into the high-flowability shield muck mud S1, mixing and stirring uniformly to obtain a mixture S2;

[0069] (3) adding a mixture of sodium metaaluminate and calcium chloride into the mixture S2, mixing and stirring uniformly to obtain the final shield muck flowable filling S3.

[0070] It is tested that the 3d average compressive strength of the in-situ shield muck flowable filling prepared in Example 1 is 0.38 MPa, and the 7d average compressive strength is 0.49 MPa. At the same time, the flowability of the shield muck flowable filling is measured to be 17 cm according to GB / T2419-2005 “Cement mortar flowability test method”.

[0071] Comparative Example 1

[0072] A kind of original state shield slag flow state filling material, including original state shield slag and solidified material, as the comparative example of example 1.It is by the following raw materials that solidified material is composed of: blast furnace slag, fly ash, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, desulfurization gypsum, and the ratio between each component is same with example 1.The mixing amount of the solidified material in the original state shield slag flow state filling material is 12%, and the preparation method of flow state filling material includes the following steps:

[0073] (1) original state shield slag is added water and is prepared into high fluidity mud shape with water content of 115%, and original state shield slag mud S1 is obtained;

[0074] (2) the mixture of blast furnace slag, fly ash, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, desulfurization gypsum is added to high fluidity shield slag mud S1, and is mixed and stirred uniformly, and finally shield slag flow state filling material S2 is obtained.

[0075] After testing, the 3d average compressive strength of the original state shield slag flow state filling material made by comparative example 1 is 0.31 MPa, and the 7d average compressive strength is 0.40 MPa.At the same time, the fluidity of the shield slag flow state filling material is 29 cm according to GB / T2419-2005 "cement mortar fluidity determination method".

[0076] As Figure 1 shown, it is the flow degree contrastive drawing of example 1 ( Figure 1 of the present application (B figure) and comparative example 1 ( Figure 1 of the present application (A figure)), it can be seen that by finally adding flowability control agent, the flowability of shield slag flow state filling material is effectively reduced, and the solidified strength is not affected.

[0077] Example 2

[0078] A kind of original state shield slag flow state filling material, including original state shield slag and solidified material, wherein solidified material is by the following mass percentage raw materials: blast furnace slag 40%, steel slag 8%, quicklime 4%, sodium carbonate 4%, sodium silicate 4%, Portland cement 23%, natural stone powder 7%, desulfurization gypsum 7%, sodium metaaluminate 2%, calcium chloride 1%.The mixing amount of the solidified material in the original state shield slag flow state filling material is 10%, and the preparation method of flow state filling material includes the following steps:

[0079] (1) original state shield slag is added water and is prepared into high fluidity mud shape with water content of 113%, and original state shield slag mud S1 is obtained;

[0080] (2) the mixture of blast furnace slag, steel slag, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, desulfurization gypsum is added to high fluidity shield slag mud S1, and is mixed and stirred uniformly, and mixture S2 is obtained.

[0081] (3) adding the mixture of sodium metaaluminate and calcium chloride into the mixture S2, mixing and stirring uniformly to obtain the final shield muck flowable filling S3.

[0082] The 3d average compressive strength of the original shield muck flowable filling prepared in this embodiment 2 is 0.28 MPa, and the 7d average compressive strength is 0.34 MPa. Meanwhile, the fluidity of the shield muck flowable filling is 19 cm according to GB / T2419-2005 "Cement mortar fluidity test method".

[0083] Comparative Example 2

[0084] An original shield muck flowable filling, including original shield muck and curing material, as a comparative example of embodiment 2. The curing material is composed of the following raw materials: blast furnace slag, steel slag, quicklime, sodium carbonate, sodium silicate, portland cement, natural stone powder, desulfurization gypsum, and the proportions between each component are the same as embodiment 2. The dosage of the curing material in the original shield muck is 10%, and the preparation method of the flowable filling includes the following steps:

[0085] (1) The original shield muck is mixed with water to prepare a high-fluidity mud with a water content of 113%, and the original shield muck mud S1 is obtained;

[0086] (2) A mixture of blast furnace slag, steel slag, quicklime, sodium carbonate, sodium silicate, portland cement, natural stone powder, and desulfurization gypsum is added to the high-fluidity shield muck mud S1, and mixed and stirred uniformly to obtain the final shield muck flowable filling S2.

[0087] The 3d average compressive strength of the original shield muck flowable filling prepared in this comparative example 2 is 0.22 MPa, and the 7d average compressive strength is 0.28 MPa. Meanwhile, the fluidity of the shield muck flowable filling is 27.5 cm according to GB / T2419-2005 "Cement mortar fluidity test method".

[0088] Embodiment 3

[0089] An original shield muck flowable filling, including original shield muck and curing material, wherein the curing material is composed of the following raw materials with mass percentage: blast furnace slag 38%, silica fume 8%, quicklime 3%, sodium carbonate 3%, sodium silicate 3%, portland cement 26%, natural stone powder 7%, desulfurization gypsum 9%, sodium metaaluminate 2%, and calcium chloride 1%. The dosage of the curing material in the original shield muck flowable filling is 10%, and the preparation method of the flowable filling includes the following steps:

[0090] (1) The original shield muck is mixed with water to form a high-fluidity slurry with a water content of 113%, and a shield muck slurry S1 is obtained;

[0091] (2) A mixture of blast furnace slag, silica fume, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, and desulfurization gypsum is added to the high-fluidity shield muck slurry S1, and mixed and stirred uniformly to obtain a mixture S2;

[0092] (3) A mixture of sodium aluminate and calcium chloride is added to the mixture S2, and mixed and stirred uniformly to obtain a final shield muck flowable filler S3.

[0093] Tests show that the 3d average compressive strength of the original shield muck flowable filler prepared in this embodiment 3 is 0.27 MPa, and the 7d average compressive strength is 0.36 MPa. At the same time, the flowability of the shield muck flowable filler is measured to be 18.5 cm according to GB / T2419-2005 "Cement mortar flowability test method".

[0094] Comparative Example 3

[0095] A kind of original shield muck flowable filler, including original shield muck and solidification material, as the comparative example of embodiment 3. Its solidification material is composed of the following raw materials: blast furnace slag, silica fume, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, and desulfurization gypsum, and the ratio between each component is the same as that of embodiment 3. The dosage of the solidification material in the original shield muck is 10%, and the preparation method of the flowable filler includes the following steps:

[0096] (1) The original shield muck is mixed with water to form a high-fluidity slurry with a water content of 113%, and a shield muck slurry S1 is obtained;

[0097] (2) A mixture of blast furnace slag, silica fume, quicklime, sodium carbonate, sodium silicate, Portland cement, natural stone powder, and desulfurization gypsum is added to the high-fluidity shield muck slurry S1, and mixed and stirred uniformly to obtain a final shield muck flowable filler S2.

[0098] Tests show that the 3d average compressive strength of the original shield muck flowable filler prepared in this comparative example 3 is 0.21 MPa, and the 7d average compressive strength is 0.27 MPa. At the same time, the flowability of the shield muck flowable filler is measured to be 27.5 cm according to GB / T2419-2005 "Cement mortar flowability test method".

[0099] Embodiment 4

[0100] A kind of in-situ shield muck flow state filler, comprising in-situ shield muck and solidified material, wherein the solidified material is composed of the following raw materials in mass percentage: blast furnace slag 36%, quicklime 3%, sodium carbonate 3%, sodium silicate 3%, portland cement 38%, construction waste recycled micro powder 6%, desulfurization gypsum 9%, sodium metaaluminate 1%, calcium chloride 1%.The dosage of the solidified material in the in-situ shield muck flow state filler is 8%, and the preparation method of the flow state filler comprises the following steps:

[0101] (1) the in-situ shield muck is adjusted into high fluidity mud with water content of 113%, to obtain in-situ shield muck slurry S1;

[0102] (2) the mixture of blast furnace slag, quicklime, sodium carbonate, sodium silicate, portland cement, construction waste recycled micro powder and desulfurization gypsum is added to the high fluidity shield muck slurry S1, and mixed and stirred uniformly to obtain mixture S2;

[0103] (3) the mixture of sodium metaaluminate and calcium chloride is added to the mixture S2, and mixed and stirred uniformly to obtain the final shield muck flow state filler S3.

[0104] Tested, the 3d average compressive strength of the in-situ shield muck flow state filler prepared in example 4 is 0.24 MPa, and the 7d average compressive strength is 0.30 MPa.Meanwhile, the flowability of the shield muck flow state filler is measured to be 21 cm according to GB / T2419-2005 "Cement mortar flowability test method".

[0105] Comparative example 4

[0106] A kind of in-situ shield muck flow state filler, comprising in-situ shield muck and solidified material, as comparative example of example 4.The solidified material is composed of the following raw materials: blast furnace slag, quicklime, sodium carbonate, sodium silicate, portland cement, construction waste recycled micro powder and desulfurization gypsum, and the ratio between each component is the same as example 4.The dosage of the solidified material in the in-situ shield muck is 8%, and the preparation method of the flow state filler comprises the following steps:

[0107] (1) the in-situ shield muck is adjusted into high fluidity mud with water content of 113%, to obtain in-situ shield muck slurry S1;

[0108] (2) the mixture of blast furnace slag, quicklime, sodium carbonate, sodium silicate, portland cement, construction waste recycled micro powder and desulfurization gypsum is added to the high fluidity shield muck slurry S1, and mixed and stirred uniformly to obtain the final shield muck flow state filler S2.

[0109] The 3d average compressive strength of the as-is shield muck flowable filling material prepared in Comparative Example 4 is 0.19 MPa, and the 7d average compressive strength is 0.25 MPa. At the same time, the flowability of the shield muck flowable filling material is 27 cm according to GB / T2419-2005 "Cement mortar flow test method".

[0110] Comparative Example 5

[0111] An as-is shield muck flowable filling material, as a comparative example of Examples 1-4. The solidification material is Portland cement, and the dosage of the solidification material in the as-is shield muck is 12%. The preparation method of the flowable filling material comprises the following steps:

[0112] (1) The as-is shield muck is mixed with water to form a high-flowability mud with a water content of 113%, and an as-is shield muck mud S1 is obtained;

[0113] (2) Portland cement is added to the high-flowability shield muck mud S1, and mixed and stirred uniformly to obtain a final shield muck flowable filling material S2.

[0114] The 3d average compressive strength of the as-is shield muck flowable filling material prepared in Comparative Example 5 is 0.12 MPa, and the 7d average compressive strength is 0.17 MPa. At the same time, the flowability of the shield muck flowable filling material is 28 cm according to GB / T2419-2005 "Cement mortar flow test method".

[0115] From the above results, it can be seen that by the flowability control method of the present application, the flowability of the as-is shield muck flowable filling material can be controlled within 22 cm, which is convenient for construction and avoids filling loss caused by high flowability. At the same time, the 7d strength of the as-is shield muck flowable filling material of the present application is above 0.3 MPa, which meets the basic backfill strength requirement in DBJ51 / T188-2022 "Pre-mixed flowable solidified soil engineering application technology standard".

[0116] In addition, other beneficial effects of the present application are as follows:

[0117] (1) No need to dehydrate or screen the as-is shield muck, simple disposal process, low cost, greatly improving the added value of the shield muck.

[0118] (2) For different types of as-is shield muck, the mix proportion can be adjusted to meet the corresponding solidification strength and flowability requirements, and the use range is wide.

[0119] (3) Large-scale disposal and resource utilization of shield muck can save shield muck transportation and disposal costs, reduce construction costs, avoid safety risks and hidden dangers caused by muck storage, and can obtain good economic, environmental and social benefits.

[0120] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Various technical features are described in this detailed description. Many of the technical features can be combined in any combination. For the sake of brevity, the combinations of these technical features are not described in every possible combination. However, all possible combinations are contemplated to be within the scope of the application.

Claims

1. A flowable fill for use in narrow spaces comprising in situ shield muck and a solidifying material, characterized in that, The solidified material comprises raw materials in the following mass percentages: alkali-activated cementitious material 30%-80%, cement 10%-40%, stone powder 1%-10%, gypsum 5%-15%, and fluidity regulator 1%-5%; The fluidity regulator comprises sodium aluminate and / or calcium chloride; The solidified material has a mass of 8-15% of the filling material; The preparation method comprises the following steps: (1) The original shield muck is mixed with water to form a high-fluidity slurry with a water content of more than 60%, thereby obtaining original shield muck slurry S1; (2) A mixture of alkali-activated cementitious material, cement, stone powder, and gypsum is added to the high-fluidity shield muck slurry S1, and mixed and stirred uniformly, thereby obtaining mixture S2; (3) The fluidity regulator is added to the mixture S2, and mixed and stirred uniformly, thereby obtaining the final shield muck fluid filling material S3.

2. The in-situ slurry backfill material for use in narrow spaces according to claim 1, characterized in that, The alkali-activated cementitious material is composed of the following raw materials in the following mass percentages: cementitious component 70%-90% and alkali activator 10%-30%.

3. The in-situ slurry backfill material for use in tight spaces of claim 2, wherein, The cementitious component is one or more of blast furnace slag, fly ash, silica fume, steel slag, and phosphorous slag.

4. The in-situ slurry backfill material for use in narrow spaces according to claim 2, wherein The alkali activator is one or more of quicklime, sodium carbonate, sodium silicate, and sodium hydroxide.

5. The in-situ slurry backfill material for use in tight spaces of claim 1, wherein, The stone powder is one or more of natural stone powder and construction waste recycled micro powder.

6. The in-situ slurry backfill material for use in tight spaces of claim 1, wherein, The gypsum is one or more of natural gypsum and desulfurization gypsum.

7. The method for producing in-situ slurry for filling narrow spaces with shield muck according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: (1) The original shield muck is mixed with water to form a high-fluidity slurry with a water content of more than 60%, thereby obtaining original shield muck slurry S1; (2) A mixture of alkali-activated cementitious material, cement, stone powder, and gypsum is added to the high-fluidity shield muck slurry S1, and mixed and stirred uniformly, thereby obtaining mixture S2; (3) The fluidity regulator is added to the mixture S2, and mixed and stirred uniformly, thereby obtaining the final shield muck fluid filling material S3.

8. Use of a flowable fill in situ of muck of a tunneling shield for narrow spaces according to any one of claims 1-6, characterized in that, The shield muck fluid filling material is used as backfilling material for narrow spaces.

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