Alkali-activated muck and decoration garbage all-solid waste flow state filling material and preparation method thereof

Abstract

The invention discloses an all-solid-waste flow-state filling material of alkali-activated muck and decoration garbage and a preparation method of the all-solid-waste flow-state filling material, and belongs to the technical field of building materials. The all-solid waste flow state filling material of the alkali-activated muck and the decoration garbage is prepared from the following raw materials in parts by mass: 10 to 20 parts of waste muck, 25 to 40 parts of decoration garbage, 1 to 5 parts of alkali activator, 10 to 20 parts of admixture and 20 to 35 parts of water. The invention further provides a corresponding preparation method of the flow-state filling material. The ratio of the volume of a slurry system to the volume of an aggregate system is controlled within the range of 2.5-3.0 so as to obtain the optimal use and construction effect. According to the invention, solid wastes (waste residue soil, decoration garbage and admixture) are used as raw materials, and then the solid wastes are subjected to alkali activation to realize recycling. The prepared flow-state filling material is good in working performance and wide in application, can be applied to backfilling projects of various deep pits, pipeline channels, mines and abutment backs, and can also be applied to the fields of road roadbeds, building foundations and the like.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a full-solid waste fluid filling material of alkali-activated slag and decoration waste and a preparation method thereof. Background Art

[0002] A large amount of decoration waste is generated during the maintenance, renovation and restoration of buildings. Due to the complex composition of decoration waste and the serious lack of disposal equipment, process and application technology, the recycled aggregates produced are of poor quality, low resource utilization rate and difficult to use. The decoration waste that is difficult to use is eventually landfilled, causing serious environmental problems. Effectively recycling decoration waste to achieve resource utilization is of great significance to sustainable development.

[0003] In addition, with the advancement of urbanization, cities have ushered in a peak in construction pit excavation and subway construction, which generates a large amount of waste soil. When recycling, sorting, processing and reusing waste soil, the prominent problem is that the water content of the waste soil is high and the quality of the recycled products is low. If it is not handled in time, it will pollute the environment, occupy land resources, and even cause safety hazards.

[0004] Therefore, resource utilization of solid wastes such as slag and decoration waste, which are extremely difficult to dispose of, is also conducive to promoting the low-carbon transformation of the industry. Existing technologies have studied the resource utilization of decoration waste or slag alone, but there is a lack of research on the combined utilization of decoration waste and slag. The technical method of preparing building materials from the two solid wastes still needs further research.

[0005] Fluid filling material is a kind of material with high fluidity. It can fill itself under its own weight or through a little vibration to form a relatively dense structural system. The characteristics of fluid filling material such as high fluidity, variable density, no sinking, and fast hardening speed can make up for the shortcomings of traditional backfill materials. At the same time, in recent years, backfill projects such as mining, urban pipe trenches, and abutments require a large amount of backfill materials. Due to the narrow shape and huge amount of these backfill parts, traditional backfill materials can no longer meet their use needs. Since decoration waste and slag are not suitable for concrete engineering, it is crucial to find an alternative solution in the construction industry to utilize a large amount of fine decoration waste aggregates and engineering slag. One of the potential utilization directions is to use alkali-activated slag and decoration waste to prepare all-solid waste fluid filling materials. Summary of the invention

[0006] The purpose of the present invention is to provide an alkali-activated all-solid waste fluid filling material of slag and renovation waste and a preparation method thereof, so as to solve the above-mentioned problems in the background technology. The present invention uses solid waste (waste slag, renovation waste and admixtures) as raw materials, and then realizes recycling of these solid wastes through alkali activation, which greatly absorbs solid wastes that are difficult to recycle and reduces the use of natural resources. The fluid filling material prepared by the present invention has good working performance and is widely used. It can be used for backfilling and pouring of various foundation pits, pipeline trenches, and mine pits, and can also be used in reinforcement fields such as roadbeds and building foundations.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide a full solid waste fluid filling material of alkali-activated slag and decoration waste, the raw materials, calculated by mass, include:

[0009] 10-20 parts of waste soil, 25-40 parts of renovation waste, 1-5 parts of alkali activator, 10-20 parts of admixture and 20-35 parts of water.

[0010] Preferably, the waste soil is waste soil generated by processing buildings, structures, and pipelines.

[0011] Preferably, the particle size of the waste soil is ≤2 mm. According to the classification of GB / T50123, sand and silt are preferably used.

[0012] Preferably, the renovation waste contains waste concrete, red bricks, ceramic tiles, aerated bricks and impurities, the impurities include plastics, wood chips and glass, and the mass proportion of the impurities is ≤2%.

[0013] Preferably, the particle size of the decoration waste is ≤4.75mm and the apparent density is 2100-2550kg / m 3 , water absorption is 8.80-15.20%, and fineness modulus is 2.3-3.0.

[0014] Preferably, the waste soil contains soil sand particles with a particle size of 0.075-2 mm and soil powder particles with a particle size of less than 0.075 mm;

[0015] The decoration waste contains decoration waste fine aggregate with a particle size of 0.075-4.75 mm and decoration waste powder particles with a particle size of less than 0.075 mm.

[0016] Preferably, the alkaline activator comprises sodium hydroxide and / or water glass.

[0017] More preferably, the purity of the sodium hydroxide is greater than 95%, and the modulus of the water glass is 2.8-3.2.

[0018] More preferably, the sodium hydroxide is used to adjust the modulus of water glass, wherein the adjusted modulus M is 0.5-1.5. WG and the mass of sodium hydroxide m SH Satisfies the relationship of formula (1).

[0019]

[0020] Among them, k1 is the mass fraction of Na2O in water glass, and k2 is the mass fraction of SiO2 in water glass.

[0021] Preferably, the admixture contains fly ash and / or slag.

[0022] More preferably, the fly ash is high-calcium fly ash.

[0023] More preferably, the alkali concentration N (in terms of Na2O) can be determined based on the mass of the sodium hydroxide, water glass, slag, and fly ash. The alkali concentration N is 2% to 10%, that is, the mass of water glass m WG , the mass of sodium hydroxide m SH , slag mass m GGBS and fly ash mass m FA Satisfies the relationship of formula (2).

[0024]

[0025] More preferably, the slag is high-activity slag powder; the grade of the high-activity slag powder is S105.

[0026] More preferably, the ratio of the sum of the volumes of the slag powder, renovation waste powder, alkali activator, admixture and water to the sum of the volumes of the slag sand and renovation waste fine aggregate is 2.5-3.

[0027] The second technical solution of the present invention is to provide a method for preparing the above-mentioned alkali-activated slag and decoration waste all-solid waste fluid filling material, comprising the following steps:

[0028] Mixing the renovation waste, waste soil and admixture to obtain a mixture;

[0029] Mixing the alkaline activator and water to obtain an alkaline activating solution;

[0030] The alkali-activated liquid is added to the mixture to obtain the alkali-activated slag and decoration waste full-solid waste fluid filling material.

[0031] Preferably, the decoration waste is saturated surface dry decoration waste; the preparation method of the saturated surface dry decoration waste is: mixing the decoration waste with water to make the decoration waste reach a saturated surface dry state.

[0032] The technical principles of the present invention are as follows:

[0033] The present invention uses slag powder, decoration waste powder, alkali activator, admixture and water in the raw materials as a slurry system, and slag sand and decoration waste fine aggregate as an aggregate system. The proportion of decoration waste and abandoned slag is adjusted by calculating the slurry-aggregate ratio. The amount of materials can be adjusted in time according to different types and ratios of construction solid waste, thereby achieving precise control in the preparation process and achieving workability that meets the use requirements.

[0034] The slag powder particles, decoration waste powder particles and admixtures in the construction solid waste and industrial solid waste of the present invention contain active calcium oxide, silicon oxide and the like, which can react with an alkali activator to generate cementitious substances such as hydrated calcium silicate, hydrated calcium aluminate and hydrated calcium alumino-silicate gel, and bond components such as slag sand particles and decoration waste fine aggregate to form early strength; therefore, the present invention can avoid the addition of other cementitious materials such as cement and lime, and is more green and environmentally friendly.

[0035] The beneficial technical effects of the present invention are as follows:

[0036] The present invention uses solid waste as raw materials, and then realizes recycling of these solid wastes by alkali activation, which greatly absorbs solid wastes that are difficult to recycle and reduces the use of natural resources. The fluid filling material prepared by the present invention has good working performance and wide application. It can be applied to backfilling and pouring of various foundation pits, pipeline trenches, and mine pits, and can also be used in reinforcement fields such as roadbeds and building foundations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 paying creative work.

[0038] Figure 1 Schematic diagram of the preparation process of Examples 1-5. DETAILED DESCRIPTION

[0039] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0040] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0041] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0042] The words “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0043] The invention discloses a fully solid waste fluid filling material of alkali-activated slag and decoration waste. The raw materials thereof include, by weight, 10-20 parts of waste slag, 25-40 parts of decoration waste, 1-5 parts of alkali activator, 10-20 parts of admixture and 20-35 parts of water.

[0044] Preferably, the waste soil with a particle size of ≤2 mm comes from the waste soil generated during the construction, reconstruction, expansion and demolition of various buildings, structures, pipelines, etc., as well as the decoration and renovation of houses by residents.

[0045] Preferably, the decoration waste contains waste concrete, red bricks, ceramic tiles, aerated bricks and impurities, the impurities include plastics, wood chips and glass, and the mass proportion of impurities is ≤2%. The particle size of the decoration waste is ≤4.75mm, and the apparent density is 2100-2550kg / m 3 , water absorption is 8.80-15.20%, and fineness modulus is 2.3-3.0.

[0046] The sodium hydroxide used in the following embodiments of the present invention is solid flake analytically pure with a purity greater than 95%. The modulus of the water glass is 3.26, the solid content is 36.36%, the Na2O content is 8.74%, and the SiO2 content is 27.62%.

[0047] The density of the slag used in the following embodiments of the present invention is 2.81 g / cm 3 , particle size <80μm, more than 50% of the particles are <10μm. The fly ash is high calcium fly ash, density 2.21g / cm 3 The water used was tap water.

[0048] Preferably, the alkali concentration N in each embodiment of the present invention is between 2% and 10%.

[0049] In the following embodiments of the present invention, the ratio of the sum of the volumes of the slag powder, the decoration waste powder, the alkali activator, the admixture and the water (recorded as Vp) to the sum of the volumes of the slag sand and the decoration waste fine aggregate (recorded as Va) is recorded as the mortar-aggregate ratio. The specific calculation formulas of Va and Vp are as follows:

[0050] Va=Vr+Vs

[0051] Among them, V a is the volume of the aggregate system, V r is the volume of fine aggregate of renovation waste, V s is the volume of soil sand particles.

[0052]

[0053] Among them, V p is the volume of the slurry system, V fr is the volume of decoration waste particles, V fs is the volume of the slag powder particles, A i is the volume of the alkaline activator (sodium hydroxide, water glass), P i is the volume of admixture (fly ash, slag).

[0054] All raw materials used in the following embodiments of the present invention are commercially available products.

[0055] The fluidity and unconfined compressive strength tests were performed on the products of each embodiment, and the test methods were as follows:

[0056] 1) Fluidity test

[0057] The fluidity test device consists of a plexiglass plate and a double-opened glass cylinder with a height of 150mm and an inner diameter of 75mm. During the test, first use a rag to wet the inner wall of the cylinder and the surface of the glass plate, and place the cylinder in the middle of the horizontal glass plate; then load the newly mixed fluid filling material into the cylinder, and use a scraper to flatten the surface after filling; after the sample is loaded, gently lift the plexiglass cylinder vertically upward. After 15 seconds, when the sample no longer spreads, use a steel ruler to measure the maximum and minimum diameters of the mixture after spreading, and take the average of the two as the flow value. In order to ensure the reliability of the test, each group of samples needs to be tested in parallel 3 times, and the average value is taken as the final flow value.

[0058] 2) Unconfined compressive strength test

[0059] The unconfined compressive strength test is carried out in accordance with the Geotechnical Test Method Standard (GB / T50123-2019). The sample size is: inner diameter 100mm, height 200mm, and curing for 28 days at 20±2℃ and 95% humidity. In order to ensure the reliability of the test, each group of samples needs to be tested in parallel 3 times, and the average value is used as the final unconfined compressive strength.

[0060] Figure 1 Schematic diagram of the preparation process of Examples 1-5.

[0061] Example 1

[0062] A fluid filling material, composed of the following raw materials in percentage by mass:

[0063] 15% waste slag (among which, the mass ratio of slag sand with a particle size of 0.075-2mm to slag powder with a particle size of <0.075mm is 0.639), 35% decoration waste (among which, the mass ratio of decoration waste fine aggregate with a particle size of 0.075-4.75mm to decoration waste powder with a particle size of <0.075mm is 9.0), 0.5% sodium hydroxide, 1.5% water glass, 10% fly ash, 10% slag and 28% water.

[0064] After calculation, the V per cubic meter in this embodiment is a 0.263m 3 , V p 0.737m 3 , the pulp-bone ratio is 2.81, the adjusted modulus M is 0.841, and the alkali concentration N is 2.6%.

[0065] Preparation of fluid filling material:

[0066] Add water to the renovation waste in advance and stew the waste to make it saturated and dry, and then mix it with waste soil, fly ash and slag to obtain a mixed material;

[0067] Mixing sodium hydroxide, water glass and water to obtain an alkaline stimulating solution;

[0068] Add alkali activating liquid into the mixture, stir evenly, and obtain the all-solid waste fluid filling material.

[0069] After testing, the fluidity of Example 1 is 220 mm, and the 28-day compressive strength is 0.75 MPa.

[0070] Example 2

[0071] A fluid filling material, composed of the following raw materials in percentage by mass:

[0072] Waste debris 14% (among which, the mass ratio of debris sand with a particle size of 0.075-2mm to debris powder with a particle size of <0.075mm is 0.639), decoration waste 34% (among which, the mass ratio of decoration waste fine aggregate with a particle size of 0.075-4.75mm to decoration waste powder with a particle size of <0.075mm is 9.0), sodium hydroxide 0.5%, water glass 1.5%, fly ash 11%, slag 11% and water 28%.

[0073] After calculation, the V per cubic meter in this embodiment is a 0.253m 3 , V p 0.747m 3 , the pulp-bone ratio is 2.94, the adjusted modulus M is 0.841, and the alkali concentration N is 2.4%.

[0074] Preparation of fluid filling material:

[0075] Add water to the renovation waste in advance and stew the waste to make it saturated and dry, and then mix it with waste soil, fly ash and slag to obtain a mixed material;

[0076] Mixing sodium hydroxide, water glass and water to obtain an alkaline stimulating solution;

[0077] Add alkali activating liquid into the mixture, stir evenly, and obtain the all-solid waste fluid filling material.

[0078] After testing, the fluidity of Example 2 is 265 mm, and the 28-day compressive strength is 0.81 MPa.

[0079] Example 3

[0080] A fluid filling material, composed of the following raw materials in percentage by mass:

[0081] Waste debris 16% (among which, the mass ratio of debris sand with a particle size of 0.075-2mm to debris powder with a particle size of <0.075mm is 0.639), decoration waste 36% (among which, the mass ratio of decoration waste fine aggregate with a particle size of 0.075-4.75mm to decoration waste powder with a particle size of <0.075mm is 9.0), sodium hydroxide 0.5%, water glass 1.5%, fly ash 9%, slag 9% and water 28%.

[0082] After calculation, the V per cubic meter in this embodiment is a 0.271m 3 , V p 0.729m 3 , the pulp-bone ratio is 2.68, the adjusted modulus M is 0.841, and the alkali concentration N is 2.9%.

[0083] Preparation of fluid filling material:

[0084] Add water to the renovation waste in advance and stew the waste to make it saturated and dry, and then mix it with waste soil, fly ash and slag to obtain a mixed material;

[0085] Mixing sodium hydroxide, water glass and water to obtain an alkaline stimulating solution;

[0086] Add alkali activating liquid into the mixture, stir evenly, and obtain the all-solid waste fluid filling material.

[0087] After testing, the fluidity of Example 3 is 195 mm, and the 28-day compressive strength is 0.63 MPa.

[0088] Example 4

[0089] A fluid filling material, composed of the following raw materials in percentage by mass:

[0090] Waste debris 12% (among which, the mass ratio of debris sand with a particle size of 0.075-2mm to debris powder with a particle size of <0.075mm is 0.639), decoration waste 28% (among which, the mass ratio of decoration waste fine aggregate with a particle size of 0.075-4.75mm to decoration waste powder with a particle size of <0.075mm is 9.0), sodium hydroxide 0.5%, water glass 1.5%, fly ash 12%, slag 12% and water 34%.

[0091] After calculation, the V per cubic meter in this embodiment is a 0.200m 3 , V p 0.800m 3 , the pulp-bone ratio is 2.81, the adjusted modulus M is 0.841, and the alkali concentration N is 2.2%.

[0092] Preparation of fluid filling material:

[0093] Add water to the renovation waste in advance and stew the waste to make it saturated and dry, and then mix it with waste soil, fly ash and slag to obtain a mixed material;

[0094] Mixing sodium hydroxide, water glass and water to obtain an alkaline stimulating solution;

[0095] Add alkali activating liquid into the mixture, stir evenly, and obtain the all-solid waste fluid filling material.

[0096] After testing, Example 4 produced severe water seepage and did not meet the use requirements.

[0097] Example 5

[0098] A fluid filling material, composed of the following raw materials in percentage by mass:

[0099] Waste debris 16% (among which, the mass ratio of debris sand with a particle size of 0.075-2mm to debris powder with a particle size of <0.075mm is 0.639), decoration waste 38% (among which, the mass ratio of decoration waste fine aggregate with a particle size of 0.075-4.75mm to decoration waste powder with a particle size of <0.075mm is 9.0), sodium hydroxide 0.5%, water glass 1.5%, fly ash 10%, slag 10% and water 24%.

[0100] After calculation, the V per cubic meter in this embodiment is a 0.295m 3 , V p 0.705m 3 , the pulp-bone ratio is 2.39, the adjusted modulus M is 0.841, and the alkali concentration N is 2.6%.

[0101] Preparation of fluid filling material:

[0102] Add water to the renovation waste in advance and stew the waste to make it saturated and dry, and then mix it with waste soil, fly ash and slag to obtain a mixed material;

[0103] Mixing sodium hydroxide, water glass and water to obtain an alkaline stimulating solution;

[0104] Add alkali activating liquid into the mixture, stir evenly, and obtain the all-solid waste fluid filling material.

[0105] After testing, the fluidity of Example 5 is too low and does not meet the use requirements.

[0106] The test results are summarized in Table 1.

[0107] Table 1 Raw material ratios and test results of each embodiment

[0108]

[0109] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A fully solid waste fluid filling material for alkali-activated slag and decoration waste, It is characterized in that Raw materials, calculated by mass, include: 10-20 parts of waste soil, 25-40 parts of renovation waste, 1-5 parts of alkali activator, 10-20 parts of admixture and 20-35 parts of water.

2. The all-solid waste fluid filling material of alkali-activated slag and decoration waste according to claim 1, It is characterized in that The waste soil contains soil sand particles with a particle size of 0.075-2 mm and soil powder particles with a particle size of less than 0.075 mm; The decoration waste contains decoration waste fine aggregate with a particle size of 0.075-4.75 mm and decoration waste powder particles with a particle size of less than 0.075 mm.

3. The all-solid waste fluid filling material of alkali-activated slag and decoration waste according to claim 1, It is characterized in that The alkaline activator comprises sodium hydroxide and / or water glass.

4. The all-solid waste fluid filling material of alkali-activated slag and decoration waste according to claim 1, It is characterized in that The admixture comprises fly ash and / or slag.

5. The all-solid waste fluid filling material of alkali-activated slag and decoration waste according to claim 2, It is characterized in that The ratio of the sum of the volumes of the slag powder particles, decoration waste powder particles, alkali activator, admixture and water to the sum of the volumes of the slag sand particles and decoration waste fine aggregate is 2.5-3.

6. A method for preparing the all-solid waste fluid filling material of alkali-activated slag and decoration waste according to any one of claims 1 to 5, It is characterized in that The following steps are involved: Mixing the renovation waste, waste soil and admixture to obtain a mixture; Mixing the alkaline activator and water to obtain an alkaline activating solution; The alkali-activated liquid is added to the mixture to obtain the alkali-activated slag and decoration waste full-solid waste fluid filling material.

7. The preparation method according to claim 6, It is characterized in that The decoration waste is saturated surface dry decoration waste; the preparation method of the saturated surface dry decoration waste is: mixing the decoration waste with water to make the decoration waste reach a saturated surface dry state.

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