CN117263643A - Two-stage regulated full-solid waste micro-expansion concrete and preparation method thereof - Google Patents

Abstract

The invention discloses a two-stage regulated full-solid waste micro-expansion concrete and a preparation method thereof, wherein the concrete comprises the following components in parts by weight: 1072.67 parts of coarse aggregate, 585.09 parts of fine aggregate, 9.75-29.25 parts of expanding agent, 458.33-477.83 parts of cementing material and 219.41 parts of water; wherein, the coarse aggregate uses gangue, the fine aggregate uses waste ceramic, the cementing material uses solid waste-based cementing material, the expanding agent uses polylactic acid to wrap carbide slag micro-expanding agent, and the water uses laboratory tap water. The invention utilizes the solid waste to develop building materials and produce building materials, can effectively realize the reduction, harmlessness and recycling of the solid waste treatment, and has important significance for energy conservation, emission reduction and waste recycling of the solid waste. Coarse and fine aggregates, cementing materials, additives and the like required by the preparation of the concrete by utilizing the solid wastes can realize the comprehensive utilization of the solid wastes and promote the green development of the concrete industry.

Description

A two-stage controlled all-solid waste micro-expanded concrete and its preparation method

Technical field

The invention specifically relates to a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof. It belongs to the field of civil engineering, the field of solid waste resource utilization, and the field of building materials concrete.

Background technique

Volume shrinkage occurs during the hardening and use of concrete. Excessive shrinkage may cause cracks in the structure and affect its performance. When preparing concrete, a certain amount of expansion agent is added to cause the concrete to expand in volume during the hardening process and offset shrinkage, thus preventing structural cracking. Currently, calcium oxide expansion agents commonly used have shortcomings such as too fast expansion rate and low effective expansion rate. Therefore, it is difficult to meet actual production needs by only using expansion agents to compensate for the shrinkage deformation of concrete.

my country's solid waste stock is large, its utilization rate is low, and it poses great ecological and environmental safety risks. The utilization of solid waste as building materials is one of the main ways to solve the current situation of its disposal. Therefore, using solid waste to prepare coarse and fine aggregates, cement and other materials, and applying them to concrete to prepare all-solid waste concrete, improving the resource utilization rate of solid waste is important for saving resources and promoting the green and high-quality development of the concrete industry. significance.

Patent CN102092976A discloses an ecological large-volume concrete expansion agent and a preparation method. Magnesite tailings and dolomite tailings are prepared into raw materials, mixed evenly, calcined at high temperature, cooled in the air, and screened to obtain the ecological large-volume concrete expansion agent. Volumetric concrete expansion agent. The invention uses CaO as the early expansion source and MgO as the late expansion source, which can reduce and compensate for the early and late shrinkage of hydraulic mass concrete. However, the expansion agent prepared by the invention has the disadvantages of too fast hydration rate of calcium oxide and low later expansion rate of concrete.

Patent CN 115180866 B discloses a hydration heat-adjusted magnesium high-efficiency anti-cracking agent and its preparation method, including the following components in mass percentage: expansion component 50-80%, hydration heat-adjusting component 1~ 5%, shrinkage reducing component 1~5%, strengthening component 10~45%. The invention can reduce the temperature shrinkage and autogenous shrinkage of concrete and improve the mechanical properties of concrete. However, the expansion component described in the invention is a magnesium oxide expansion component, which has a low early expansion rate and cannot compensate for the early shrinkage of concrete.

Patent CN 116730680 A discloses a high crack-resistant concrete and its preparation method. The raw materials include water, coarse aggregate, fine aggregate, water, polycarboxylate water-reducing agent, calcium-magnesium composite expansion agent, fly ash, Rubber powder modified multi-size mixed fiber materials and adhesives are invented to have higher strength and better crack resistance. Patent CN 115304316 B discloses a shrinkage-compensating concrete and its preparation method. The raw materials include: siderite, graphite tailings, cement, water-reducing agent, water-retaining agent, fly ash, coarse aggregate, river sand and water . The concrete prepared by the invention has good compressive strength, strong impermeability and high density. The above invention uses solid waste such as fly ash, siderite, graphite tailings, etc. as admixtures to improve concrete performance, but the amount of solid waste in concrete is small, and the utilization rate of solid waste in concrete is low.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof.

The shrinkage deformation of concrete will bring safety hazards to the project. The use of expansion agents can compensate for the deformation caused by concrete shrinkage. Among them, the early expansion rate of magnesium oxide expansion agents is low and cannot compensate for the early shrinkage of concrete. However, calcium oxide expansion agents react quickly with water. The hydration reaction of calcium oxide often ends before the cement hardens, thus causing the concrete to shrink. The effective expansion rate is low and cannot compensate for the later shrinkage deformation of concrete. Solid waste has the characteristics of complex composition, difficult treatment, and serious environmental pollution. Using solid waste to develop building materials and produce building material raw materials can effectively achieve "reduction, harmlessness, and resource utilization" of solid waste treatment, which is beneficial to energy conservation. Emission reduction and turning solid waste into treasure are of great significance. Using solid waste to prepare coarse and fine aggregates, cementitious materials, admixtures, etc. required for concrete can achieve comprehensive utilization of solid waste and promote the green development of the concrete industry.

The technical solution adopted by the present invention is: a two-stage controlled all-solid waste micro-expansion concrete, including the following components by weight: 1072.67 parts of coarse aggregate, 585.09 parts of fine aggregate, 9.75~29.25 parts of expansion agent, gelling agent 458.33~477.83 parts of material and 219.41 parts of water; among them, coal gangue is used as the coarse aggregate, waste ceramics are used as the fine aggregate, solid waste-based cementing material is used as the cementing material, polylactic acid-coated carbide slag micro-expansion agent is used as the expansion agent, and water Use laboratory tap water.

Specifically, the coal gangue was taken from Ordos City, Inner Mongolia Autonomous Region. The chemical composition of the coal gangue is: SiO ₂ is 33.74%, Al ₂ O ₃ is 31.67%, CaO is 1.81%, SO ₃ is 1.59%, and TiO ₂ is 1.21 %, Fe ₂ O ₃ is 0.74%, MgO is 0.64%, and other oxides are 28.6%. The bulk density of coal gangue is 1306kg/m ³ , the apparent density is 2659kg/m ³ , and the water absorption rate is 5.32%.

Specifically, the waste ceramics are obtained from the waste ceramics produced during the production process of Jingdezhen Shenda Ceramics Factory. The apparent density of waste ceramics is 2460kg/m ³ . The chemical composition of waste ceramics includes: SiO ₂ is 67.82%, Al ₂ O ₃ is 20.57%, K ₂ O is 3.87%, Fe ₂ O ₃ is 2.32%, CaO is 1.88%, Na ₂ O is 0.85%, SO ₃ It is 0.82%, MgO is 0.21%, and other oxides are 1.66%. The particle size distribution of waste ceramic fine aggregate is: 0.08~0.16mm accounts for 13%, 0.16~0.5mm accounts for 20%, 0.5~1.0mm accounts for 34%, and 1.0~1.6mm accounts for 26% , 1.6~2.0mm accounts for 7%.

Specifically, the chemical composition of the solid waste-based cementitious material is: SiO ₂ is 11.85%, Al ₂ O ₃ is 18.44%, CaO is 47.37%, SO ₃ is 14.93%, TiO ₂ is 0.45%, Fe ₂ O ₃ is 1.41%, Na ₂ O is 1.98%, MgO is 1.36%, and other oxides are 2.21%.

The above-mentioned two-stage controlled preparation method of all-solid waste micro-expanded concrete includes the following steps:

Step 1: After cleaning and drying the gangue, put it into a crusher for crushing. After screening, coarse coal gangue aggregate with a particle size range of 5 to 20 mm is obtained.

Step 2: Clean and dry the waste ceramics, use a crusher to crush the waste ceramics, use a pulverizer to grind the waste ceramics, and use a vibrating screen machine to screen the waste ceramics to obtain waste ceramic fine aggregate.

Step 3: Prepare polylactic acid-coated carbide slag microexpansion agent raw materials including carbide slag, polylactic acid, and ethanol. The main component of polylactic acid is polyester polymer. The boiling point of ethanol is 78°C. The main component of calcium carbide slag is calcium hydroxide. Calcium carbide slag is calcined at high temperature to form calcium oxide, and a chemical reaction occurs: Ca(OH) ₂ →CaO+H ₂ O, where the calcination temperature is 800~900°C.

Calcide carbide slag at high temperature to obtain calcium oxide; put ethanol into a beaker, dissolve polylactic acid in ethanol, the mass ratio of polylactic acid and ethanol is 0.8:1; add calcium carbide slag calcined at high temperature to polylactic acid / ethanol solution, stir evenly, and the mass proportion of carbide slag is 60% to 90%; put the beaker containing the above mixed solution into a water bath for heating, where the water bath temperature is 85°C and the heating time is 15 minutes. The ethanol is heated and stirred to evaporate and condense into a solid; after cooling to room temperature, the ethanol is crushed, ground, and sieved to obtain a particle size of more than 150 μm to obtain a polylactic acid-coated carbide slag microexpansion agent.

Step 4: The raw materials for preparing the solid waste-based cementitious material include the following components by weight: 30% coal gangue, 50% carbide slag, and 20% desulfurization gypsum. The chemical composition of coal gangue is: SiO ₂ is 33.74%, Al ₂ O ₃ is 31.67%, CaO is 1.81%, SO ₃ is 1.59%, TiO ₂ is 1.21%, Fe ₂ O ₃ is 0.74%, MgO is 0.64% , other oxides are 28.6%. The chemical composition of carbide slag is: SiO ₂ is 7.62%, Al ₂ O ₃ is 0.33%, CaO is 67.26%, SO ₃ is 1.09%, TiO ₂ is 0.09%, Na ₂ O is 1.24%, and other oxides are 22.37 %. The chemical composition of desulfurization gypsum is: SiO ₂ is 7.21%, Al ₂ O ₃ is 0.31%, CaO is 25.62%, SO ₃ is 47.62%, Na ₂ O is 3.91%, and other oxides are 15.33%.

Clean and dry the coal gangue, put it into a crusher for crushing, grind it with a ball mill, dry it in an oven at 105°C to a constant weight, take it out and pass it through a 200-mesh square hole sieve; also put the carbide slag and desulfurization gypsum into In the oven, dry to constant weight at 105°C, take it out and pass it through a 200-mesh square hole sieve; weigh the coal gangue, carbide slag and desulfurization gypsum according to the proportions, put them into a mixer and mix them thoroughly, then add 8% of the total mass of the raw materials ~10% water and stir evenly; put the raw material into a steel mold and press it into a small test cake of Ф6mm×5mm. Put the test cake into a blast drying oven with a temperature of 105℃ and dry it for 3 hours to make the The water evaporates, making the raw material easier to burn; place the raw material in a high-temperature box furnace for calcination. Immediately after the calcination is completed, take out the test cake and cool it to room temperature; break the test cake into small pieces and grind it with a grinder , the grinding time is set to 5 minutes, and after grinding, pass through a 200-mesh square hole sieve; mix the dihydrate gypsum with the above mixture at a mass ratio of 5% to obtain a solid waste-based cementitious material.

Specifically, the calcination system in step 4 is: from room temperature to 950°C, the heating rate is set to 10°C/min, with the purpose of removing crystal water in the raw material; when 950°C to 1290°C, the heating rate is set to 5°C/min. min, the purpose of reducing the heating rate is to allow the raw material balls to fully react; when the temperature reaches 1290°C, keep it warm for 45 minutes. During the high-temperature calcination process, calcium oxide, silicon oxide and calcium sulfate in the raw materials react chemically to form calcium sulfoaluminate. The reaction equation is: 3CaO+3Al ₂ O ₃ +CaSO ₄ →C ₄ A ₃ S.

The micro-expansion performance of the all-solid waste micro-expansion concrete of the present invention is regulated in two stages. The first-stage expansion is provided by the polylactic acid-coated carbide slag micro-expansion agent, and the second-stage expansion is provided by the solid waste-based cementitious material. The two-stage regulation is fully The control mechanism of solid waste micro-expansion concrete is as follows:

(1) The expansion of concrete in the first stage is mainly provided by the polylactic acid-coated carbide slag micro-expansion agent prepared above. The carbide slag is calcined at high temperature to generate calcium oxide, and the calcium oxide is hydrated to generate calcium hydroxide. While the solid phase volume increases, , the local accumulation of hydration products leads to an increase in pore volume, thereby causing the volume expansion of the slurry in concrete. Since calcium oxide undergoes an exothermic reaction when it meets water, it will lead to shortcomings such as fast hydration rate and low effective expansion rate. Polylactic acid-coated carbide slag micro-expansion agent can delay the hydration time, reduce the reaction rate, and increase the effective expansion rate of concrete. Among them, the hydration reaction equation of calcium oxide is: CaO+H ₂ O → Ca(OH) ₂ .

(2) The second stage of concrete expansion is mainly provided by solid waste-based cementitious materials. The main components of solid waste-based cementitious materials are calcium sulfoaluminate (C ₄ A ₃ S), calcium sulfate (CaSO ₄ ), C ₄ A ₃ S and CaSO ₄ react with water to form ettringite (C ₃ A ₃ ·CS ·32H) and aluminum gel (AH ₃ ). The reaction equation is: C ₄ A ₃ S+2CS+38H→ C ₃ A ₃ ·CS·32H+2AH ₃ , the growth of ettringite crystals leads to the expansion of concrete. As the hydration reaction proceeds, CaSO ₄ is consumed, and calcium sulfoaluminate undergoes a hydration reaction to generate monosulfide hydrated calcium sulfoaluminate (C ₃ A·CS·12H). The reaction equation is: C ₄ A ₃ S+ 18H→C ₃ A·CS·12H+4AH ₃ , the monosulfur type calcium sulfoaluminate hydrate crystal generated can also provide late expansion for concrete. As the hydration reaction proceeds, the hydration reaction of the solid waste-based cementitious material generates ettringite and monosulfur-type calcium sulfoaluminate hydrate crystals, which provide the second stage of expansion for the concrete.

Beneficial effects of the present invention:

1. Use coal gangue, calcium carbide slag, desulfurization gypsum, waste ceramics and other solid waste to prepare all-solid waste concrete, which can consume solid waste on a large scale and reduce environmental pollution.

2. The polylactic acid-coated calcium carbide slag micro-expansion agent prepared using polylactic acid and carbide slag as raw materials can provide the first stage of expansion for concrete. Calcium oxide reacts chemically with water to generate calcium hydroxide. The increase in solid phase volume causes the concrete to expand. . Since calcium oxide reacts quickly with water and the hydration rate is too fast, using polylactic acid to wrap calcium oxide can effectively delay the hydration process and increase the effective expansion rate of concrete.

3. Use coal gangue, calcium carbide slag, and desulfurization gypsum as raw materials to prepare solid waste-based cementitious materials, which can provide the second stage of expansion for concrete. The main component of solid waste-based cementitious materials is calcium sulfoaluminate (C ₄ A ₃ S) , calcium sulfate (CaSO ₄ ), among which, C ₄ A ₃ S and CaSO ₄ react with water to form ettringite (C ₃ A ₃ · CS · 32H), and C ₄ A ₃ S reacts with water to form ettringite. Generates monosulfide calcium sulfoaluminate hydrate (C ₃ A·CS·12H). As the hydration reaction proceeds, the hydration reaction of the solid waste-based cementitious material generates ettringite and monosulfur-type calcium sulfoaluminate hydrate crystals, which provide the second stage of expansion for the concrete.

4. The present invention provides a two-stage controlled all-solid waste micro-expansion concrete and a preparation method thereof. The two-stage control method can effectively increase the expansion rate of concrete and compensate for the deformation of concrete due to shrinkage.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments.

The mix proportion design of concrete is carried out according to the "Design Regulations for Ordinary Concrete" (JGJ 55-2011) and "Concrete Expansion Agent" (GB/T 23439-2017). The mix proportion design table is as follows:

Table 1 Mix proportion design

Among them, coal gangue is used as the coarse aggregate, waste ceramics are used as the fine aggregate, solid waste-based cementing material is used as the cementing material, polylactic acid-coated carbide slag micro-expansion agent is used as the expansion agent, and laboratory tap water is used as the water.

Example 1

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate 9.75 parts of expansion agent, 477.83 parts of solid waste-based cementitious material, and 219.41 parts of water.

Example 2

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate 14.6 parts of expansion agent, 472.98 parts of solid waste-based cementitious material, and 219.41 parts of water.

Example 3

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate 19.5 parts of expansion agent, 468.08 parts of solid waste-based cementitious material, and 219.41 parts of water.

Example 4

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate There are 24.4 parts of expansion agent, 463.18 parts of solid waste-based cementitious material, and 219.41 parts of water.

Example 5

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate 0 parts of expansion agent, 458.33 parts of solid waste-based cementitious material, and 219.41 parts of water.

Comparative example 1

The invention provides a two-stage controlled all-solid waste micro-expanded concrete and a preparation method thereof, which includes the following components by weight: 1072.67 parts of coal gangue coarse aggregate, 585.09 parts of waste ceramic fine aggregate, polylactic acid-coated carbide slag micro-aggregate 0 parts of expansion agent, 487.58 parts of solid waste-based gelling material, and 219.41 parts of water.

The concrete microstrain was tested according to the "Standard for Test Methods of Long-term Performance and Durability of Concrete" (GB/T 50082-2009). The measured micro-strain results of a two-stage controlled all-solid waste micro-expanded concrete are as follows:

Table 2 Concrete microstrain/με

The results show: (1) According to Examples 1 to 5, with the increase in the amount of polylactic acid-coated carbide slag microexpansion agent, the microstrain of the solid waste concrete gradually increases, and the early microstrain growth rate accelerates, indicating that the microstrain The early expansion effect of the expansion agent is good, providing the first stage of expansion for the concrete. (2) According to Examples 1 to 5 and Comparative Example 1, it can be seen that without the addition of expansion agent, the microstrain of concrete gradually increases with age, indicating that solid waste-based cementitious materials can be used as the expansion source of fully solid waste concrete. Provides a second stage of expansion for concrete.

It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented using existing technologies.

Claims (6)

1. A two-stage regulated full-solid waste micro-expansion concrete is characterized in that: comprises the following components in parts by weight: 1072.67 parts of coarse aggregate, 585.09 parts of fine aggregate, 9.75-29.25 parts of expanding agent, 458.33-477.83 parts of cementing material and 219.41 parts of water; wherein, the coarse aggregate uses gangue, the fine aggregate uses waste ceramic, the cementing material uses solid waste-based cementing material, the expanding agent uses polylactic acid to wrap carbide slag micro-expanding agent, and the water uses laboratory tap water.

2. The two-stage regulated total solid waste micro-expansive concrete according to claim 1, wherein: the chemical composition of the gangue is as follows: siO (SiO) ₂ 33.74% of Al ₂ O ₃ 31.67%, caO 1.81%, SO ₃ 1.59% TiO ₂ 1.21% of Fe ₂ O ₃ 0.74%, mgO 0.64%, other oxides 28.6%; the bulk density of the gangue is 1306kg/m ³ Apparent density of 2659kg/m ³ The water absorption was 5.32%.

3. The two-stage regulated total solid waste micro-expansive concrete according to claim 2, wherein: the apparent density of the waste ceramic is 2460kg/m ³ The method comprises the steps of carrying out a first treatment on the surface of the The chemical composition of the waste ceramic comprises: siO (SiO) ₂ 67.82, al ₂ O ₃ 20.57%, K ₂ O is 3.87%, fe ₂ O ₃ 2.32%, caO 1.88%, na ₂ O is 0.85%, SO ₃ 0.82%, mgO 0.21%, other oxides 1.66%; the particle size distribution of the waste ceramic fine aggregate is as follows: 13% of 0.08-0.16 mm, 20% of 0.16-0.5 mm, 34% of 0.5-1.0 mm, 26% of 1.0-1.6 mm and 7% of 1.6-2.0 mm.

4. A two-stage controlled all-solid-waste micro-expansive concrete according to claim 3, characterized in that: the solid waste-based cementing material comprises the following chemical components: siO (SiO) ₂ 11.85% of Al ₂ O ₃ 18.44%, caO 47.37%, SO ₃ 14.93% TiO ₂ 0.45% of Fe ₂ O ₃ 1.41% of Na ₂ O is 1.98%, mgO is 1.36%, and other oxides are 2.21%.

5. The method for preparing the two-stage regulated full-solid waste micro-expansive concrete according to claim 1, 2, 3 or 4, which is characterized by comprising the following steps: the method comprises the following steps:

step one: washing and airing the gangue, putting the gangue into a crusher for crushing, and screening to obtain gangue coarse aggregate with the particle size within a range of 5-20 mm;

step two: cleaning and airing the waste ceramics, crushing the waste ceramics by using a crusher, grinding the waste ceramics by using a crusher, and screening the waste ceramics by using a vibrating screen to obtain waste ceramic fine aggregate;

step three: the polylactic acid coated carbide slag micro-expanding agent is prepared from carbide slag, polylactic acid and ethanol; the polylactic acid is mainly composed of polyester polymers; the boiling point of ethanol is 78 ℃; main component of carbide slagCalcium hydroxide is adopted, calcium oxide is generated by calcining carbide slag at high temperature, and chemical reaction is carried out: ca (OH) ₂ →CaO+H ₂ O, wherein the calcination temperature is 800-900 ℃;

calcining carbide slag at high temperature to obtain calcium oxide; putting ethanol into a beaker, dissolving polylactic acid in the ethanol, wherein the mass ratio of the polylactic acid to the ethanol is 0.8:1; adding the carbide slag subjected to high-temperature calcination into polylactic acid/ethanol solution, and uniformly stirring, wherein the mass ratio of the carbide slag is 60% -90%; heating the beaker filled with the mixed solution in a water bath kettle for 15min at the water bath temperature of 85 ℃, heating and stirring in the water bath kettle to evaporate ethanol and coagulate into solid; cooling to room temperature, crushing, grinding, sieving to obtain polylactic acid coated carbide slag micro-expanding agent with particle size over 150 μm;

step four: the raw materials for preparing the solid waste-based cementing material comprise the following components in parts by weight: 30% of gangue, 50% of carbide slag and 20% of desulfurized gypsum; the chemical composition of the gangue is as follows: siO (SiO) ₂ 33.74% of Al ₂ O ₃ 31.67%, caO 1.81%, SO ₃ 1.59% TiO ₂ 1.21% of Fe ₂ O ₃ 0.74%, mgO 0.64%, other oxides 28.6%; the chemical composition of the carbide slag is as follows: siO (SiO) ₂ 7.62% of Al ₂ O ₃ 0.33%, 67.26% CaO and SO ₃ 1.09%, tiO ₂ 0.09%, na ₂ O1.24% and other oxides 22.37%; the chemical composition of the desulfurized gypsum is as follows: siO (SiO) ₂ 7.21% of Al ₂ O ₃ 0.31%, 25.62% CaO and SO ₃ 47.62, na ₂ O3.91% and other oxides 15.33%;

washing and airing gangue, putting the gangue into a crusher for crushing, ball-milling the gangue by using a ball mill, putting the gangue into an oven for drying at 105 ℃ until the gangue is constant in weight, taking the gangue out, and sieving the gangue with a 200-mesh square-hole sieve; placing carbide slag and desulfurized gypsum into an oven, drying at 105 ℃ to constant weight, taking out, and sieving with a 200-mesh square-hole sieve; weighing coal gangue, carbide slag and desulfurized gypsum according to a proportion, putting the mixture into a stirrer for fully mixing, and then adding water accounting for 8% -10% of the total mass of the raw materials for uniformly stirring; placing the raw material into a steel mould to be pressed into small test cakes with the diameter of phi 6mm multiplied by 5mm, placing the test cakes into a blast drying oven with the temperature of 105 ℃ to be dried for 3 hours, and evaporating the water in the raw material to enable the raw material to be easier to be sintered; placing the raw materials in a high-temperature box-type furnace for calcination, immediately taking out the test cakes after the calcination is completed, and cooling to room temperature; crushing the test cake into small blocks, grinding the small blocks by a grinder, setting the grinding time to be 5min, and sieving the small blocks by a 200-mesh square hole sieve after grinding; and uniformly mixing the dihydrate gypsum with the mixture in a mass ratio of 5% to prepare the solid waste base cementing material.

6. The preparation method of the two-stage regulated full-solid waste micro-expansive concrete is characterized by comprising the following steps of: the calcination system in the fourth step is as follows: the temperature is set to be 10 ℃ per minute from room temperature to 950 ℃, and the purpose is to remove the crystal water in the raw material; setting the heating rate to be 5 ℃/min at 950 ℃ to 1290 ℃, wherein the purpose of reducing the heating rate is that raw material balls can fully react; heating to 1290 ℃, and preserving heat for 45min; in the high-temperature calcination process, calcium oxide, silicon oxide and calcium sulfate in the raw materials react chemically to generate calcium sulfoaluminate.