Coal-based solid waste roadway bottom plate surface layer concrete material and proportion determination method

Abstract

The invention belongs to the technical field of coal mine safety mining, and relates to a coal-based solid waste roadway bottom plate surface layer concrete material and a proportion determination method. The coal-based solid waste roadway bottom plate surface layer concrete material is prepared by mixing the following raw materials in parts by weight: 10 to 90 parts of cement, 80 to 150 parts of sand, 200 to 300 parts of gangue, 15 to 150 parts of coarse slag in coal gasification ash, 10 to 100 parts of fine slag in coal gasification ash and 35 to 60 parts of water. Wherein the crushed and screened gangue serves as coarse aggregate, the sand and coarse slag of the coal gasification ash serve as fine aggregate, the cement and the activated fine slag of the coal gasification ash serve as binding materials, the crushed and screened gangue particles are larger than or equal to 4.75 mm, and the fineness modulus of the coarse slag in the coal gasification ash is 1.6-3.7. The use requirements of the mine laneway bottom plate are met, the technical problems of low solid waste mixing amount, high material cost and poor high-temperature resistance are solved, and remarkable economic and environmental benefits are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste resource utilization, and in particular relates to a coal-based solid waste roadway floor surface concrete material and a method for determining its proportion. Background Art

[0002] While large-scale coal mining supports economic development, it also raises the challenge of managing coal-based solid waste. For example, coal gangue accounts for 10% to 20% of total raw coal production, with annual emissions exceeding 700 million tons. Meanwhile, coal gasification ash, a byproduct of clean coal utilization, has an annual output exceeding 50 million tons. Currently, both types of solid waste are primarily stored in open-air dumps, which not only encroach on land resources but also pose a threat to the ecological environment through the leaching of heavy metals, severely hindering the sustainable development of the coal chemical industry. In underground coal mine engineering, increasing mining depths impact the stability of tunnels with geostress and high temperatures. While domestic and international scholars have proposed theories such as the New Austrian Tunneling Method (NATM) and surrounding rock strength enhancement for tunnel roof and side support, tunnel floors are susceptible to floor heave and cracking due to long-term exposure to dynamic equipment loads, high geostress, and mine water erosion. Research has shown that reinforcing the tunnel floor with a concrete surface layer can significantly improve overall tunnel stability. Traditional tunnel floor slab surface concrete typically uses cement as a binder (300-500kg / m³), along with fine aggregate sand (600-800kg / m³) and coarse aggregate crushed stone (1000-1300kg / m³), sometimes incorporating solid wastes such as gangue and fly ash. However, traditional tunnel floor slab surface concrete faces technical bottlenecks such as a low content of coal-based solid waste (≤30%) and prone to cracking in high-temperature environments. Furthermore, this type of concrete consumes as much as 300-500kg / m³ of cement, resulting in high material costs.

[0003] Therefore, providing a coal-based solid waste roadway floor surface concrete material that overcomes the low solid waste content, high material cost, and poor high temperature resistance of existing roadway floor surface concrete material preparation technology has significant economic and environmental benefits. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a coal-based solid waste tunnel floor surface concrete material and a method for determining the proportion, which overcomes the technical difficulties of low solid waste content, high material cost, and poor high temperature resistance, and has significant economic and environmental benefits.

[0005] In order to solve the above technical problems, the present invention provides a coal-based solid waste roadway floor surface concrete material, which is mixed with the following raw materials in parts by weight:

[0006] 10-90 parts of cement, 80-150 parts of sand, 200-300 parts of gangue, 15-150 parts of coarse slag from coal gasification ash, 10-100 parts of fine slag from activated coal gasification ash, and 35-60 parts of water;

[0007] Among them, the gangue after crushing and screening is used as coarse aggregate, sand and coarse slag of coal gasification ash are used as fine aggregate, cement and fine slag in activated coal gasification ash are used as cementitious materials, the gangue particles after crushing and screening are ≥4.75mm, and the fineness modulus of coarse slag in coal gasification ash is 1.6~3.7.

[0008] Preferably, a coal-based solid waste roadway floor surface concrete material is prepared by mixing the following raw materials in parts by weight:

[0009] 50 to 90 parts of cement, 90 to 130 parts of sand, 240 to 280 parts of gangue, 15 to 80 parts of coarse slag of coal gasification ash, 10 to 50 parts of fine slag of coal gasification ash and 40 to 50 parts of water.

[0010] Preferably, a coal-based solid waste roadway floor surface concrete material is prepared by mixing the following raw materials in parts by weight:

[0011] 80 parts of cement, 100 parts of sand, 260 parts of gangue, 22 parts of coarse slag of coal gasification ash, 20 parts of fine slag of coal gasification ash and 43 parts of water.

[0012] The present invention also provides a method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway, comprising the following steps:

[0013] According to the purpose of the mine tunnel, the performance requirements of the concrete material of the bottom slab of the coal-based solid waste tunnel are determined by comprehensively considering the influence of mining stress, high temperature environment underground, compaction of transportation equipment, mine water immersion, and service life of the tunnel;

[0014] Based on the performance requirements of the concrete material for the floor slab of coal-based solid waste roadways, the water-cement ratio and sand ratio of the concrete material for the floor slab of coal-based solid waste roadways are calculated. The replacement rate of coarse slag in coal gasification ash and fine slag in activated coal gasification ash is also considered, and a test on the proportion of concrete material for the floor slab of coal-based solid waste roadways is designed.

[0015] Prepare raw materials for preparing coal-based solid waste roadway floor surface concrete materials;

[0016] Weighing corresponding raw materials according to the test mix ratio, stirring and mixing, and preparing a coal-based solid waste roadway floor surface layer concrete material, and testing one or more properties of the coal-based solid waste roadway floor surface layer concrete material sample;

[0017] Determine whether the test results meet the roadway floor performance requirements and decide whether to optimize the test plan; when the test results meet the roadway floor performance requirements and national and industry standards, determine the ratio of the coal-based solid waste roadway floor surface concrete material.

[0018] Preferably, when the test results do not meet the tunnel floor performance requirements and national and industry standards, it is necessary to continue to optimize the test plan by adjusting the water-cement ratio, sand ratio, and coarse and fine slag replacement rates of coal gasification ash.

[0019] Preferably, the specific steps of the method for calculating the water-cement ratio and sand ratio of the coal-based solid waste roadway floor surface concrete material are:

[0020] According to the strength requirements of the surface concrete material performance requirements of the coal-based solid waste roadway floor, the water-cement ratio of the surface concrete material is calculated taking into account the influence coefficient of coal gasification ash;

[0021] The sand ratio of the surface concrete material is determined based on the water-cement ratio of the surface concrete material; then the amount of sand and gangue is calculated using the volume method based on the amount of cement.

[0022] Preferably, the replacement rates of the coarse slag in the coal gasification ash and the fine slag in the activated coal gasification ash are both equivalent replacement rates, the coarse slag after screening is used as a secondary fine aggregate to replace sand, with a replacement rate of 10% to 100%, and the fine slag after activation is used as a secondary cementitious material to replace cement, with a replacement rate of 10% to 100%.

[0023] Preferably, the mechanical properties include compressive strength, axial compressive strength, flexural strength and splitting tensile strength; the workability includes slump, expansion, consistency and water bleeding rate; the volume stability includes early cracking sensitivity, shrinkage, expansion coefficient and creep; the durability includes high temperature resistance, wear resistance, permeability resistance and sulfate corrosion resistance.

[0024] Preferably, the preparation of raw materials for the coal-based solid waste tunnel floor surface concrete material includes crushing and screening the gangue to achieve the required particle size gradation, screening the coarse slag in the coal gasification ash according to the required fineness modulus, activating the fine slag in the coal gasification ash, and purchasing cement and sand as required. The fine slag in the coal gasification ash is activated by any one of mechanical activation, chemical activation or mechanical and chemical activation.

[0025] The present invention also provides an application of a coal-based solid waste tunnel floor surface concrete material in underground tunnel floor filling, ground road engineering and building construction.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The raw materials used in the preparation of coal-based solid waste tunnel floor surface concrete materials in the present invention are mostly industrial solid waste generated in the process of coal mining and utilization, which accounts for a high proportion. It can absorb industrial solid waste on a large scale and reduce the preparation cost of materials. Moreover, the industrial solid waste generated in the process of coal mining and utilization can be obtained locally, avoiding high transportation costs and further reducing the cost of materials.

[0028] At the same time, the crushed and screened gangue used in the coal-based solid waste tunnel floor surface concrete material provided by the present invention has good physical and mechanical properties and can be used as coarse aggregate for concrete; the coarse slag in the coal gasification ash has a particle size range close to that of sand, and its chemical composition also contains relatively high SiO2, Al2O3, and CaO, and can be used as fine aggregate for concrete to replace sand; the fine slag in the coal gasification ash contains rich inorganic mineral components, such as aluminosilicate minerals, which have volcanic ash activity and can promote hydration reactions to generate cementitious substances such as hydrated calcium silicate, which can be used as a cementitious material to replace cement after activation, thereby increasing the doping amount of solid waste.

[0029] Moreover, the aluminum silicate minerals in the gangue can undergo a directional synergistic reaction with the active amorphous SiO2 / Al2O3 in the coal gasification ash in the cement alkaline environment to form highly stable hydration products. The low thermal conductivity of the gangue can be combined with the lightweight properties of the coal gasification ash to reduce the thermal expansion coefficient of the concrete and reduce the risk of cracking caused by temperature stress, making it suitable for the high ground temperature environment of deep tunnels.

[0030] The performance of the coal-based solid waste tunnel floor surface concrete material prepared by the present invention meets national and industry standards and can meet the requirements for underground tunnel floor filling. As a type of concrete material, the coal-based solid waste tunnel floor surface concrete material prepared by the present invention can also be extended to ground road engineering and construction fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a method for preparing a coal-based solid waste roadway floor surface concrete material according to the present invention. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0033] The inventors found that the traditional roadway floor surface concrete material is limited in the amount of coal-based solid waste (≤30%) and the amount of cement is high (300-500kg / m 3) and cracking in high-temperature environments, making it difficult to meet the needs of deep tunnel reinforcement. Based on the physical and chemical properties of coal gangue and coal gasification ash, a synergistic utilization technology was proposed: crushing and screening the coal gangue to replace crushed stone as coarse aggregate, screening the coarse slag of coal gasification ash to replace sand as fine aggregate, and activating and modifying the fine slag of coal gasification ash to replace cement as a cementitious material. This design breaks through the restrictions on the amount of coal-based solid waste, reduces the amount of cement, and simultaneously utilizes the active ingredients in the solid waste to improve the high-temperature resistance of the material, achieving the synergistic goals of large-scale solid waste disposal and low-cost reinforcement of the tunnel floor.

[0034] In light of this, the present invention provides a coal-based solid waste roadway floor surface concrete material and a method for determining its formulation. This overcomes the technical challenges of low solid waste content, high material costs, and poor high-temperature resistance, offering significant economic and environmental benefits. Furthermore, by utilizing industrial solid waste generated during coal production and utilization to prepare the roadway floor surface concrete material, the material enhances the stability of underground coal mine roadway floors and meets the operational requirements of the roadway.

[0035] The present invention provides a coal-based solid waste roadway floor surface concrete material, which is composed of the following raw materials in parts by weight:

[0036] 100 parts of cement, 80-150 parts of sand, 200-300 parts of gangue, 15-150 parts of coarse slag from coal gasification ash, 10-100 parts of fine slag from activated coal gasification ash, and 35-60 parts of water;

[0037] Among them, the gangue after crushing and screening is used as coarse aggregate, sand and coarse slag of coal gasification ash are used as fine aggregate, cement and fine slag of activated coal gasification ash are used as cementitious materials, the gangue particles after crushing and screening are ≥4.75mm, and the fineness modulus of coarse slag in coal gasification ash is 1.6~3.7.

[0038] Specifically, a coal-based solid waste roadway floor surface concrete material is composed of the following raw materials in parts by weight:

[0039] 100 parts of cement, 80 to 150 parts of sand, 200 to 300 parts of gangue, 15 to 150 parts of coarse slag of coal gasification ash, 10 to 100 parts of fine slag of coal gasification ash and 35 to 60 parts of water.

[0040] Specifically, a coal-based solid waste roadway floor surface concrete material is composed of the following raw materials in parts by weight:

[0041] 80 parts of cement, 100 parts of sand, 260 parts of gangue, 22 parts of coarse slag of coal gasification ash, 20 parts of fine slag of coal gasification ash and 43 parts of water.

[0042] like Figure 1A method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway is provided, comprising the following steps:

[0043] According to the purpose of the mine tunnel, the performance requirements of the concrete material of the bottom slab of the coal-based solid waste tunnel are determined by comprehensively considering the influence of mining stress, high temperature environment underground, compaction of transportation equipment, mine water immersion, and service life of the tunnel;

[0044] Based on the performance requirements of the concrete material for the floor slab of coal-based solid waste roadways, the water-cement ratio and sand ratio of the concrete material for the floor slab of coal-based solid waste roadways are calculated. The replacement rate of coarse slag in coal gasification ash and fine slag in activated coal gasification ash is also considered, and a test on the proportion of concrete material for the floor slab of coal-based solid waste roadways is designed.

[0045] Prepare raw materials for preparing coal-based solid waste roadway floor surface concrete materials;

[0046] According to the test mix ratio, corresponding raw materials are weighed and stirred for 3 to 5 minutes to prepare a coal-based solid waste roadway floor surface layer concrete material, and one or more properties of the coal-based solid waste roadway floor surface layer concrete material sample are tested;

[0047] Determine whether the test results meet the roadway floor performance requirements and decide whether to optimize the test plan; when the test results meet the roadway floor performance requirements and national and industry standards, determine the ratio of the coal-based solid waste roadway floor surface concrete material.

[0048] Specifically, when the test results do not meet the tunnel floor performance requirements and national and industry standards, it is necessary to continue to optimize the test plan by reducing the water-cement ratio and the coarse and fine slag replacement rates of coal gasification ash.

[0049] Specifically, the specific steps of the method for calculating the water-cement ratio and sand ratio of the coal-based solid waste roadway floor surface concrete material are as follows:

[0050] According to the strength requirements of the surface concrete material performance requirements of the coal-based solid waste roadway floor, the water-cement ratio of the surface concrete material is calculated taking into account the influence coefficient of coal gasification ash;

[0051] The sand ratio of the surface concrete material is determined based on the water-cement ratio of the surface concrete material; then the amount of sand and gangue is calculated using the volume method based on the amount of cement.

[0052] Specifically, the replacement rates of the coarse slag in the coal gasification ash and the fine slag in the activated coal gasification ash are both equivalent replacement rates. The coarse slag after screening is used as a secondary fine aggregate to replace sand with a replacement rate of 10% to 100%, and the fine slag after activation is used as a secondary cementitious material to replace cement with a replacement rate of 10% to 100%.

[0053] Specifically, the mechanical properties include compressive strength, axial compressive strength, flexural tensile strength and splitting tensile strength; the working performance includes slump, expansion, consistency and water bleeding rate; the volume stability includes early cracking sensitivity, shrinkage, expansion coefficient and creep; the durability includes high temperature resistance, wear resistance, permeability resistance and sulfate corrosion resistance.

[0054] Specifically, the preparation of raw materials for the coal-based solid waste tunnel floor surface concrete material includes crushing and screening the gangue to achieve the required particle size gradation, screening the coarse slag in the coal gasification ash according to the required fineness modulus, activating the fine slag in the coal gasification ash, and purchasing cement and sand as required. The fine slag in the coal gasification ash is activated by any one of mechanical activation, chemical activation or mechanical and chemical activation.

[0055] Based on the above-mentioned method for determining the proportion of concrete materials for the bottom plate surface layer of a coal-based solid waste roadway, a specific embodiment is given.

[0056] Example 1

[0057] A method for determining a formula of a concrete material for a coal-based solid waste roadway floor surface layer comprises the following steps:

[0058] (1) Determine the performance requirements of the surface concrete material of the roadway floor: The roadway floor of a certain mine's mining face is severely deformed, and it is decided to strengthen the roadway floor by filling it with concrete. Considering that the roadway is in a high-temperature working environment for a long time, the high temperature environment is the main factor to determine the performance of the surface concrete material. At the same time, the performance requirements of the surface concrete material in this embodiment are that the compressive strength reaches C30 (30MPa), the flexural strength reaches 5MPa, and the thermal expansion coefficient is less than 8×10 -6 / ℃.

[0059] (2) According to the strength requirements of C30 concrete, the influence coefficient of coal gasification ash is selected as 0.75. According to the Design Code for Ordinary Concrete Mix Ratio (JGJ55-2011), the water-cement ratio of the surface concrete material is calculated to be 0.45, the sand ratio is selected as 34%, and the cement (density 3000kg / m 3 ) dosage is 430kg / m 3 , the volume method can be used to calculate the sand (density 2600kg / m 3 ) and gangue (density 2600kg / m 3 ) are 560kg / m 3 and 1087kg / m 3 .

[0060] (3) Select values ​​within the range near the calculated water-cement ratio and sand ratio. In this embodiment 1, the water-cement ratio is selected as 0.43, the sand ratio is selected as 30%, the coarse slag replacement rate is selected as 10%, and the fine slag replacement rate is selected as 10%.

[0061] (4) The gangue produced by the mine was collected, crushed and screened, and the gangue particles with a nominal particle size of 5 mm to 20 mm were selected as coarse aggregate. The coarse slag in the coal gasification ash was screened according to the fineness modulus of 2.5. The fine slag of the coal gasification ash was activated by mechanical activation and ball milled in an industrial ball mill for 8 hours. The sand used was medium sand with a fineness modulus of 2.5, and the cement used was PO 42.5 ordinary Portland cement.

[0062] (5) The raw materials were weighed according to the ratio in the test plan and stirred for 3 to 5 minutes, and then the slurry was placed in a mold to prepare a standard sample. After curing in a curing box for 28 days, the coal-based solid waste roadway bottom slab surface concrete material was obtained.

[0063] Example 2

[0064] The only difference between Example 2 and Example 1 is that in Example 2, the water-cement ratio is selected as 0.43, the sand rate is selected as 32%, the coarse slag replacement rate is selected as 20%, and the fine slag replacement rate is selected as 20%.

[0065] Example 3

[0066] The only difference between Example 3 and Example 1 is that in Example 3, the water-cement ratio is selected as 0.43, the sand rate is selected as 34%, the coarse slag replacement rate is selected as 30%, and the fine slag replacement rate is selected as 30%.

[0067] Example 4

[0068] The only difference between Example 4 and Example 1 is that in Example 4, the water-cement ratio is selected as 0.43, the sand rate is selected as 36%, the coarse slag replacement rate is selected as 40%, and the fine slag replacement rate is selected as 40%.

[0069] Example 5

[0070] The only difference between Example 5 and Example 1 is that in Example 5, the water-cement ratio is selected as 0.45, the sand rate is selected as 30%, the coarse slag replacement rate is selected as 20%, and the fine slag replacement rate is selected as 30%.

[0071] Example 6

[0072] The only difference between Example 6 and Example 1 is that in Example 6, the water-cement ratio is selected as 0.45, the sand rate is selected as 32%, the coarse slag replacement rate is selected as 10%, and the fine slag replacement rate is selected as 40%.

[0073] Example 7

[0074] The only difference between Example 7 and Example 1 is that in Example 7, the water-cement ratio is selected as 0.45, the sand rate is selected as 34%, the coarse slag replacement rate is selected as 40%, and the fine slag replacement rate is selected as 10%.

[0075] Example 8

[0076] The only difference between Example 8 and Example 1 is that in Example 8, the water-cement ratio is selected as 0.45, the sand rate is selected as 36%, the coarse slag replacement rate is selected as 30%, and the fine slag replacement rate is selected as 20%.

[0077] Example 9

[0078] The only difference between Example 9 and Example 1 is that in Example 9, the water-cement ratio is selected as 0.47, the sand rate is selected as 30%, the coarse slag replacement rate is selected as 30%, and the fine slag replacement rate is selected as 40%.

[0079] Example 10

[0080] The only difference between Example 10 and Example 1 is that in Example 10, the water-cement ratio is selected as 0.47, the sand rate is selected as 32%, the coarse slag replacement rate is selected as 40%, and the fine slag replacement rate is selected as 30%.

[0081] Example 11

[0082] The only difference between Example 11 and Example 1 is that in Example 11, the water-cement ratio is selected as 0.47, the sand rate is selected as 34%, the coarse slag replacement rate is selected as 10%, and the fine slag replacement rate is selected as 20%.

[0083] Example 12

[0084] The only difference between Example 12 and Example 1 is that in Example 12, the water-cement ratio is selected as 0.47, the sand rate is selected as 36%, the coarse slag replacement rate is selected as 20%, and the fine slag replacement rate is selected as 10%.

[0085] Example 13

[0086] The only difference between Example 13 and Example 1 is that in Example 13, the water-cement ratio is selected as 0.49, the sand rate is selected as 30%, the coarse slag replacement rate is selected as 40%, and the fine slag replacement rate is selected as 20%.

[0087] Example 14

[0088] The only difference between Example 14 and Example 1 is that in Example 14, the water-cement ratio is selected as 0.49, the sand rate is selected as 32%, the coarse slag replacement rate is selected as 30%, and the fine slag replacement rate is selected as 10%.

[0089] Example 15

[0090] The only difference between Example 15 and Example 1 is that in Example 15, the water-cement ratio is selected as 0.49, the sand rate is selected as 34%, the coarse slag replacement rate is selected as 20%, and the fine slag replacement rate is selected as 40%.

[0091] Example 16

[0092] The only difference between Example 16 and Example 1 is that in Example 16, the water-cement ratio is selected as 0.49, the sand rate is selected as 36%, the coarse slag replacement rate is selected as 10%, and the fine slag replacement rate is selected as 30%.

[0093] The coal-based solid waste roadway floor surface concrete materials prepared in Examples 1 to 16 were subjected to compression tests, flexural tests, and thermal expansion tests. The test results of the coal-based solid waste roadway floor surface concrete material ratio test are shown in Table 1.

[0094] Table 1 Test results of concrete material ratios for the floor surface layer of coal-based solid waste roadway

[0095]

[0096] According to the test results in Table 1, the performance requirements of the surface concrete material in Example 1 are as follows: the compressive strength reaches C30 (30 MPa), the flexural strength reaches 5 MPa, and the thermal expansion coefficient is less than 8×10 -6 Based on the requirements given in Example 1, only a small part of the above Examples 2 to 16 can meet the performance requirements of the surface concrete material in Example 1.

[0097] In order to save material costs, the amount of cement should be minimized. In order to dispose of more coal-based solid waste, the proportion of waste should be as high as possible. Therefore, the preferred ratio of this embodiment 1 is: water-cement ratio 0.43, sand ratio 32%, coarse slag replacement rate 20%, and fine slag replacement rate 20%. Under this ratio, the amount of coal-based solid waste reaches 59.6%, and the thermal expansion coefficient is 6.2×10 -6 / °C, indicating that the concrete's volume changes less at high temperatures, reducing the risk of temperature-induced cracking. According to the calculation formula in the "Code for Design of Ordinary Concrete Mix Proportions" (JGJ55-2011), the concrete material for the floor surface layer of the coal-based solid waste roadway at this time is a mixture of 80 parts cement, 100 parts sand, 260 parts gangue, 22 parts coarse coal gasification ash residue, 20 parts fine coal gasification ash residue, and 43 parts water.

[0098] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A coal-based solid waste roadway floor surface concrete material, characterized in that: It is made by mixing the following raw materials in parts by weight: 10-90 parts of cement, 80-150 parts of sand, 200-300 parts of gangue, 15-150 parts of coarse slag from coal gasification ash, 10-100 parts of fine slag from activated coal gasification ash, and 35-60 parts of water; Among them, the gangue after crushing and screening is used as coarse aggregate, sand and coarse slag of coal gasification ash are used as fine aggregate, cement and fine slag in activated coal gasification ash are used as cementitious materials, the gangue particles after crushing and screening are ≥4.75mm, and the fineness modulus of coarse slag in coal gasification ash is 1.6~3.

7.

2. The coal-based solid waste roadway floor surface concrete material according to claim 1, characterized in that: The coal-based solid waste roadway floor surface concrete material is made by mixing the following raw materials in parts by weight: 50 to 90 parts of cement, 90 to 130 parts of sand, 240 to 280 parts of gangue, 15 to 80 parts of coarse slag of coal gasification ash, 10 to 50 parts of fine slag of coal gasification ash and 40 to 50 parts of water.

3. The coal-based solid waste roadway floor surface concrete material according to claim 1, characterized in that: The coal-based solid waste roadway floor surface concrete material is made by mixing the following raw materials in parts by weight: 80 parts of cement, 100 parts of sand, 260 parts of gangue, 22 parts of coarse slag of coal gasification ash, 20 parts of fine slag of coal gasification ash and 43 parts of water.

4. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to any one of claims 1 to 3, characterized in that: The steps include: According to the purpose of the mine tunnel, the performance requirements of the concrete material of the bottom slab of the coal-based solid waste tunnel are determined by comprehensively considering the influence of mining stress, high temperature environment underground, compaction of transportation equipment, mine water immersion, and service life of the tunnel; Based on the performance requirements of the concrete material for the floor slab of coal-based solid waste roadways, the water-cement ratio and sand ratio of the concrete material for the floor slab of coal-based solid waste roadways are calculated. The replacement rate of coarse slag in coal gasification ash and fine slag in activated coal gasification ash is also considered, and a test on the proportion of concrete material for the floor slab of coal-based solid waste roadways is designed. Prepare raw materials for preparing coal-based solid waste roadway floor surface concrete materials; Weighing corresponding raw materials according to the test mix ratio, stirring and mixing, and preparing a coal-based solid waste roadway floor surface layer concrete material, and testing one or more properties of the coal-based solid waste roadway floor surface layer concrete material sample; Determine whether the analysis test results meet the roadway floor performance requirements, and decide whether to optimize the test plan; When the test results meet the tunnel floor performance requirements and national and industry standards, the proportion of the coal-based solid waste tunnel floor surface concrete material is determined.

5. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to claim 4, characterized in that: When the test results do not meet the tunnel floor performance requirements and national and industry standards, it is necessary to continue to optimize the test plan by adjusting the water-cement ratio, sand ratio, and the coarse and fine slag replacement rates of coal gasification ash.

6. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to claim 4, characterized in that: The specific steps of the method for calculating the water-cement ratio and sand ratio of the coal-based solid waste roadway floor surface concrete material are as follows: According to the strength requirements of the surface concrete material performance requirements of the coal-based solid waste roadway floor, the water-cement ratio of the surface concrete material is calculated taking into account the influence coefficient of coal gasification ash; The sand ratio of the surface concrete material is determined based on the water-cement ratio of the surface concrete material; then the amount of sand and gangue is calculated using the volume method based on the amount of cement.

7. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to claim 4, characterized in that: The replacement rates of coarse slag in the coal gasification ash and fine slag in the activated coal gasification ash are both equivalent replacement rates. The coarse slag after screening is used as a secondary fine aggregate to replace sand with a replacement rate of 10% to 100%. The fine slag after activation is used as a secondary cementitious material to replace cement with a replacement rate of 10% to 100%.

8. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to claim 4, characterized in that: The mechanical properties include compressive strength, axial compressive strength, flexural strength and splitting tensile strength; the working performance includes slump, expansion, consistency and water bleeding rate; the volume stability includes early cracking sensitivity, shrinkage, expansion coefficient and creep; the durability includes high temperature resistance, wear resistance, permeability resistance and sulfate corrosion resistance.

9. The method for determining the proportion of concrete materials for the floor surface layer of a coal-based solid waste roadway according to claim 4, characterized in that: The preparation of raw materials for coal-based solid waste tunnel floor surface concrete materials includes crushing and screening gangue to achieve the required particle size gradation, screening the coarse slag in the coal gasification ash according to the required fineness modulus, activating the fine slag in the coal gasification ash, and preparing cement and sand. The fine slag in the coal gasification ash is activated by any one of mechanical activation, chemical activation or mechanical and chemical activation.

10. Use of the coal-based solid waste tunnel floor surface concrete material according to claim 1 in underground tunnel floor filling, ground road engineering and building construction.

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