METHOD FOR PREPARING CONCRETE BASED ON GGBS, SILICON-ALUMINUM COMPOUNDS AND CO2 WASTE GAS

Abstract

A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas includes: putting a certain quantity of GGBS, silicon-aluminum compounds and water into a ball milling tank; introducing CO.sub.2 waste gas into the tank, and stopping the introduction when gas pressure in the tank reaches a standard; and starting the ball milling tank, and repeating the gas charging and ball milling for multiple times until a median size reaches the standard and CO.sub.2 is completely reacted and adsorbed by the GGBS, and finally preparing concrete from a GGBS mixture meeting requirements. According to the method, by adding the silicon-aluminum compounds into the GGBS, and under a mechanical action of the ball milling machine, the GGBS is promoted to react with and adsorb CO.sub.2.

Claims

1. A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas, comprising the following steps: (1) weighing a certain quantity of GGBS, silicon-aluminum compounds and distilled water, premixing in a mixer, and putting into a ball milling tank with aluminum oxide as a ball milling medium; (2) introducing, by using an inflator pump, CO.sub.2 waste gas into the ball milling tank, and turning off the inflator pump when gas pressure in the tank reaches a standard; (3) starting a ball milling machine, milling at a speed of 400-600 rpm for 10 to 20 min, then standing still, repeating operations in step (2), then continuing the milling, and repeating the operations for multiple times until a specified mass M of CO.sub.2 waste gas is introduced, when the CO.sub.2 waste gas introduced at the last time is not enough to enable the gas pressure in the tank to reach the standard, filling the tank with nitrogen until the gas pressure in the tank reaches the standard, and controlling, by using an industrial air cooling machine, a temperature of the ball milling tank to be 202 C. throughout the process; (4) measuring a median size of a mixture of GGBS and silicon-aluminum compounds, and if the median size cannot meet requirements, continuing the ball milling in nitrogen until the required mixture of GGBS and silicon-aluminum compounds is obtained; (5) mixing the mixture of GGBS and silicon-aluminum compounds obtained in step (4) with Portland cement to obtain a GGBS-cement mixture, adding water according to a mass ratio of water to GGBS-cement mixture of (0.35-0.41):1, and mixing with a certain quantity of coarse and fine aggregate to prepare slag concrete; and (6) pouring the slag concrete obtained in step (5) into a mold, vibrating to compact, then sealing the mold, curing for 24 h at a temperature of 22+2 C. and a relative humidity greater than or equal to 90%, demoulding, and curing to a specified age, wherein in step (1), when the mass of GGBS is known, the mass of silicon-aluminum compounds added into the ball milling tank is calculated according to the following formula: $m_{\mathrm{SA}}=\frac{{\mathrm{SSA}}_{\mathrm{SA}}}{{\mathrm{SSA}}_S}\left(m_S-m_{\mathrm{CaO}}-m_{\mathrm{MgO}}\right),$ in the formula, m.sub.SA is the mass of silicon-aluminum compounds; SSA.sub.SA and SSA.sub.S are specific surface areas of the silicon-aluminum compounds and the GGBS, respectively; w is an empirical coefficient inferred according to an influence degree of a porosity of silicon-aluminum compounds on carbon mineralization efficiency of the GGBS, and a value range is 0.843-0.951; ms is the mass of GGBS; m.sub.CaO is a total mass of calcium oxide in the mixture of GGBS and silicon-aluminum compounds; and m.sub.MgO is a total mass of magnesium oxide in the mixture of GGBS and silicon-aluminum compounds.

2. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 1, wherein a ratio of the mass of distilled water added in step (1) to a total mass of the GGBS and the silicon-aluminum compounds is 0.1:1.

3. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 2, wherein the silicon-aluminum compounds are construction materials rich in SiO.sub.2 and Al.sub.2O.sub.3, and comprise but are not limited to metakaolin, fly ash and a mixture of the two.

4. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 3, wherein in step (2), when the pressure reaches 190-210 kPa, the gas pressure in the tank is considered to reach the standard.

5. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 4, wherein in step (3), the ball milling machine mills at a speed of 500 rpm for 15 min, and then stands still for 10 min.

6. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 5, wherein in step (4), the median size of the mixture of GGBS and silicon-aluminum compounds is required to be 8.8-9.2 micrometers.

7. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 6, wherein a total mass m.sub.CO.sub.2 of CO.sub.2 required to be reacted and adsorbed by the mixture of GGBS and silicon-aluminum compounds is: $m_{{\mathrm{CO}}_2}=\left(\frac{m_{\mathrm{CaO}}}{M_{\mathrm{CaO}}}+\frac{m_{\mathrm{MgO}}}{M_{\mathrm{MgO}}}\right)M_{{\mathrm{CO}}_2}\left(1+\frac{m_{\mathrm{SA}}}{m_{\mathrm{SA}}+m_S}\right)$ in the formula, M.sub.CaO, M.sub.MgO and M.sub.CO.sub.2 represent molar masses pf calcium oxide, magnesium oxide and carbon dioxide, respectively; is the empirical coefficient with a value range of 0.45-0.65; and a value range of 8 is 1.1-1.4; the CO.sub.2 waste gas comprises one or more of CO.sub.2-containing industrial waste gases emitted from coal-fired power plants, and iron and steel production, or a combination thereof, and according to a total mass m.sub.CO.sub.2 of CO.sub.2 required to be reacted and adsorbed by the mixture of GGBS and silicon-aluminum compounds, the required mass M of the waste gas introduced into the tank is calculated by the following formula: $m_{{\mathrm{CO}}_2}=\frac{\mathrm{xN}}{1.112}+0.718\left(M-x\right),$ $M=.Math.m_n{K}_n,$ in the formula, x is the mass of the industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; N indicates a proportion of CO.sub.2 in the industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; xN/1.112 indicates the mass of CO.sub.2 in the industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; M is the mass of the waste gas introduced into the tank, and is also the total mass of all industrial waste gases in the CO.sub.2 waste gas; and 0.718 (M) is a sum of CO.sub.2 content of other industrial waste gases in the CO.sub.2 waste gas, m.sub.n is the separate mass of each industrial waste gas, and K.sub.n is a proportion of CO.sub.2 in each industrial waste gas.

8. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 7, wherein in step (5), the amount of Portland cement is determined according to the mass of the mixture of GGBS and silicon-aluminum compounds: $m_c=\frac{m_{{\mathrm{CO}}_2}}{M_{{\mathrm{CO}}_2}}{M}_{C}0.8,$ in the formula, mc is the required mass of Portland cement; Mc indicates a molar mass of carbonates generated in carbon mineralization; and a value of is 2.72-4.27.

9. The method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas according to claim 8, wherein the silicon-aluminum compounds are metakaolin, and mass parts of GGBS, metakaolin and distilled water are 27, 3 and 3, respectively; and the mass part of the aluminum oxide in the ball milling tank is 50; and when the slag concrete is prepared after the ball milling, 35 parts of Portland cement, 23 parts of water, 99 parts of fine aggregate natural sand, and 147 parts of coarse aggregate granite are used.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] FIG. 1 is a flowchart of the present disclosure.

[0062] FIG. 2 is a structural schematic diagram of a ball milling tank.

[0063] In the drawings, 1-ball milling tank, 2-inflator pump, 3-pressure gauge, 4-inlet valve, 5-outlet valve, 6-GGBS mixture, 7-temperature detector, 8-gas storage tank, 9-recovery tank, 10-gas delivering pipe, 11-exhaust pipe.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] To make to-be-solved technical problems, technical solutions and advantages of the present disclosure clearer, the present disclosure is described in detail below in conjunction with the accompanying drawings and embodiments, but is not limited to this.

[0065] Anything that is not detailed in the present disclosure shall follow the conventional technology in the art.

Embodiment 1

[0066] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas, as shown in FIG. 1 and FIG. 2, includes the following steps:

[0067] A certain quantity of GGBS, silicon-aluminum compounds and distilled water is weighed, premixed in a mixer, and put into a ball milling tank 1 with aluminum oxide as a ball milling medium; and the silicon-aluminum compounds are a construction material rich in SiO.sub.2 and Al.sub.2O.sub.3, and include, but are not limited to metakaolin, fly ash and a mixture of the two.

[0068] An inflator pump 2 is used to introduce CO.sub.2 waste gas into the ball milling tank 1, and the inflator pump is turned off when gas pressure in the tank reaches a standard; and

[0069] when a reading of a pressure gauge 3 is 200 kPa, the gas pressure in the tank is considered to reach the standard.

[0070] A ball milling machine 1 is started to mill at a speed of 400-600 rpm for 20 min, and then stands still; after operations in step (2) are repeated, the milling is continued, and the process is repeated for multiple times until a specified mass M of CO.sub.2 waste gas is introduced and reacted completely or adsorbed by a GGBS mixture; and when the CO.sub.2 waste gas introduced at the last time is not enough to make the gas pressure in the tank reach the standard, nitrogen is used to fill the tank until the gas pressure in the tank reaches the standard, and an industrial air cooling machine is used to control a temperature of the ball milling tank to be 202 C. throughout the process;

[0071] As shown in FIG. 2, a feeding port of the ball milling tank 1 is provided with an inlet valve 4, the inlet valve 4 is connected with an inflator pump 2, and a discharging port is provided with an outlet valve 5 and a pressure gauge 3; the inflator pump 2 is connected with a gas storage tank 8 through a gas delivering pipe 10, and CO.sub.2 waste gas is stored in the gas storage tank 8; the outlet valve 5 is connected with a recovery tank 9 through an exhaust pipe 11; the GGBS mixture 6 is stored in the ball milling tank 1; and a temperature detector 7 is arranged in the ball milling machine. In the present disclosure, the inlet valve and the outlet valve are used to control the introduction and discharging of the CO.sub.2 waste gas; the pressure in the tank is monitored by the pressure gauge 3 to judge whether CO.sub.2 in the tank is full and is reacted completely; and before introducing the CO.sub.2 waste gas, nitrogen shall be introduced for 10 min to exhaust the air in the tank.

[0072] A laser particle size analysis method is used to measure a median size of a mixture of GGBS and silicon-aluminum compounds, if the median size cannot meet the requirement, the ball milling needs to be continued in nitrogen until the required mixture of GGBS and silicon-aluminum compounds is obtained. The mixture of GGBS and silicon-aluminum compounds, Portland cement, coarse and fine aggregate are used together to prepare slag concrete. In a milling process, a part of CO.sub.2 is dissolved in water and reacts with calcium and magnesium ions in the mixture to generate carbonates, and the other part is adsorbed physically by the GGBS into pores. By adding the silicon-aluminum compounds, the porosity of the mixture is increased, so that more CO.sub.2 can be adsorbed; and the mechanical action of the ball milling machine on the GGBS mixture can promote the adsorption of CO.sub.2 by the GGBS, so that the mass of the adsorbed CO.sub.2 is increased, and the hydration activity of the GGBS is improved;

[0073] In the milling process, a part of CO.sub.2 is dissolved in water and reacts with calcium and magnesium ions in the GGBS mixture to generate carbonates, and the other part is adsorbed physically by the GGBS mixture into the pores. By adding the silicon-aluminum compounds, the porosity of the mixture is increased, so that more CO.sub.2 can be adsorbed; and the mechanical action of the ball milling machine on the GGBS mixture can promote the GGBS to adsorb CO.sub.2, so that the mass of the adsorbed CO.sub.2 is increased, and the hydration activity of the GGBS is improved.

[0074] The mixture of GGBS and silicon-aluminum compounds obtained in step (4) is mixed with Portland cement to obtain a GGBS-cement mixture, water is added according to a mass ratio of water to GGBS-cement mixture of (0.35-0.41):1, and then the GGBS-cement mixture is mixed with a certain quantity of coarse and fine aggregate to prepare the slag concrete;

[0075] The coarse aggregate adopts granite with a maximal particle size of 7-9 mm, the fine aggregate adopts natural sand, and a fineness modulus of a mixture of coarse and fine aggregate is 4.0-4.5. In the hydration process of the slag concrete, CO.sub.2 adsorbed in step (3) may have a beneficial carbonation reaction to promote the hydration; and active silicon dioxide and aluminum oxide in the silicon-aluminum compounds react with calcium hydroxide released by the cement hydration to generate stable CSH gel and hydrated calcium aluminate. Since the calcium hydroxide is consumed, the hydration of the cement may also be promoted.

[0076] The slag concrete obtained in step (5) is poured into a mold, and vibrated for 3 min to compact, then the mold is sealed, then curing is performed at a temperature of 22+2 C. and a relative humidity greater than or equal to 90% for 24 h, demoulding is performed, and then the concrete is cured in a standard environment until a specified age is reached.

Embodiment 2

[0077] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 1, in a reaction, the mass of CO.sub.2 reacting with calcium and magnesium to generate the carbonate is mainly related to the mass of calcium oxide and magnesium oxide in the mixture of GGBS and silicon-aluminum compounds, and the mass of the adsorbed CO.sub.2 is mainly related to the porosity of the GGBS after being mixed with the silicon-aluminum compounds. In step (1), when the mass of the GGBS is known, the mass of the silicon-aluminum compounds added into the ball milling tank is calculated according to the following formula:

[00006]$m_{\mathrm{SA}}=\frac{{\mathrm{SSA}}_{\mathrm{SA}}}{{\mathrm{SSA}}_S}\left(m_S-m_{\mathrm{CaO}}-m_{\mathrm{MgO}}\right),$

[0078] in the formula, m.sub.SA is the mass of the silicon-aluminum compounds; SSA.sub.SA and SSA.sub.S are specific surface areas (that may be determined by a low-temperature nitrogen adsorption method) of the silicon-aluminum compounds and the GGBS, respectively; is an empirical coefficient inferred according to an influence degree of a porosity of the silicon-aluminum compounds on the carbon mineralization efficiency of the GGBS, and a value range is 0.843-0.951; ms is the mass of the GGBS; m.sub.CaO is a total mass of calcium oxide in the mixture of GGBS and silicon-aluminum compounds; and m.sub.MgO is a total mass of magnesium oxide in the mixture of GGBS and silicon-aluminum compounds.

[0079] A ratio of the mass of distilled water added in step (1) to a total mass of GGBS and silicon-aluminum compounds is 0.1:1.

[0080] In step (4), a median size of the mixture of GGBS and silicon-aluminum compounds is required to be 8.8-9.2 micrometers. When the particle size of the carbonate is greater than that of the GGBS mixture, the hydration products per unit volume of the slag concrete are reduced, which shows a diluting effect, and may reduce the mechanical properties and durability of the slag concrete. According to the present disclosure, during the ball milling, by controlling the milling speed, the pressure, the temperature and the time, the fineness of the carbonate generated by carbonation is in a nanoscale, and the carbonate with the particle size greater than that of the GGBS mixture may not be generated, which may not produce an adverse effect on the particle size distribution of the GGBS mixture and the properties of the slag concrete.

Embodiment 3

[0081] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 2, in the present disclosure, by controlling parameters such as the amount of the silicon-aluminum compounds, pressure during ball milling, time, temperature, etc., a mass ratio of the reacted CO.sub.2 to the adsorbed CO.sub.2 is about 4.0 to 2.5, so that the carbonate generated by milling and the adsorbed CO.sub.2 can play an optimal activation role in the hydration of the GGBS and cement.

Embodiment 4

[0082] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 3, a total mass of CO.sub.2 during the ball milling is related to a content of calcium and magnesium oxides in the GGBS and a porosity of the silicon-aluminum compounds. When excessive CO.sub.2 waste gas is introduced, carbonation of the GGBS mixture may generate excessive carbonates, so that an average pore size of the GGBS mixture is reduced, the capacity of the GGBS mixture for adsorbing CO.sub.2 is weakened, and the hydration activity of the GGBS and the freezing resistance of the prepared slag concrete are reduced. By controlling the total mass of the introduced CO.sub.2, the carbonation reaction is ensured to generate a proper amount of carbonate, and the total mass m.sub.CO.sub.2 of CO.sub.2 required to be reacted and adsorbed by the mixture of GGBS and silicon-aluminum compounds is as follows:

[00007]$m_{{\mathrm{CO}}_2}=\left(\frac{m_{\mathrm{CaO}}}{M_{\mathrm{CaO}}}+\frac{m_{\mathrm{MgO}}}{M_{\mathrm{MgO}}}\right)M_{{\mathrm{CO}}_2}\left(1+\frac{m_{\mathrm{SA}}}{m_{\mathrm{SA}}+m_S}\right),$

[0083] in the formula, M.sub.CaO, M.sub.MgO and M.sub.CO.sub.2 represent molar masses of calcium oxide, magnesium oxide and carbon dioxide, respectively; is an empirical coefficient inferred according to the activity of alkaline-earth metallic oxides in the material, and a value range is 0.45-0.65; and is a coefficient related to the porosity of the added silicon-aluminum compounds, and a value range is 1.1-1.4.

[0084] The CO.sub.2 waste gas includes one or more of CO.sub.2-containing industrial waste gases emitted from coal-fired power plants, or a combination of, and iron and steel production, and according to the total mass m.sub.CO.sub.2 of CO.sub.2 required to be reacted and adsorbed by the mixture of GGBS and silicon-aluminum compounds, a required mass M of the waste gas introduced into the tank is calculated by the following formula:

[00008]$m_{{\mathrm{CO}}_2}=\frac{\mathrm{xN}}{1.112}+0.718\left(M-x\right),$$M=.Math.m_n{K}_n,$

[0085] in the formula, x is the mass of industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; N indicates a proportion of CO.sub.2 in the industrial waste gas with the highest CO.sub.2 content the CO.sub.2 waste gas; xN/1.112 indicates the mass of CO.sub.2 in the industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; 1.112 is an empirical coefficient inferred according to the CO.sub.2 content in the industrial waste gas with the highest CO.sub.2 content in the CO.sub.2 waste gas; M is the mass of the waste gas introduced into the tank and also the total mass of all industrial waste gases in the CO.sub.2 waste gas; and 0.718 (M) is a sum of CO.sub.2 content of other industrial waste gases in the CO.sub.2 waste gas, and 0.718 is an empirical coefficient inferred according to the proportion sum of the CO.sub.2 content of other industrial waste gases in the CO.sub.2 waste gas; m.sub.n is the separate mass of each industrial waste gas, and K.sub.n is a proportion of CO.sub.2 in each industrial waste gas.

[0086] Since the CO.sub.2 waste gas contains various industrial waste gases, and the CO.sub.2 content in different types of industrial waste gases is different, the utilization efficiency in carbon mineralization is also different, and a required mass of various industrial waste gases may be determined by the above formula.

[0087] Due to different sources of the CO.sub.2 waste gas, the proportion of each component in chemical compositions is sometimes quite different, and the components are complex. The empirical coefficient has a correction effect, which improves the applicability of the formula to various types of CO.sub.2 waste gases.

[0088] The empirical coefficients 1.112 and 0.718 are obtained through fitting based on the data of CO.sub.2 in multiple groups of industrial waste gases using software, which are representative because the empirical coefficients are obtained from extensive data analysis.

[0089] Preferably, the milled GGBS mixture contains carbonates and CO.sub.2 adsorbed in the pores, and in the hydration process after the GGBS mixture is mixed with the cement, excessive carbonates and CO.sub.2 may not improve the hydration activity of the GGBS and cement. In order to achieve the optimal activation and hydration effect of the carbonized GGBS mixture, in step (5), the amount of Portland cement is determined according to the mass of the mixture of GGBS and silicon-aluminum compounds:

[00009]$m_c=\frac{m_{{\mathrm{CO}}_2}}{M_{{\mathrm{CO}}_2}}{M}_{C}0.8,$

[0090] in the formula, mc is a required mass of Portland cement; Mc indicates a molar mass of the carbonate generated by carbon mineralization; 0.8 is a ratio of the mass of CO.sub.2 for carbon mineralization in the GGBS mixture to the total mass of CO.sub.2; and is a parameter related to the efficiency of the carbonate for activating the cement and is valued at 2.72-4.27.

Embodiment 5

[0091] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 5, the silicon-aluminum compounds are metakaolin, and mass parts of the GGBS, the metakaolin and the distilled water are 27, 3, and 3, respectively; and the mass part of aluminum oxide in the ball milling tank is 50; and

[0092] When the slag concrete is prepared after the ball milling, 35 parts of Portland cement, 23 parts of water, 99 parts of fine aggregate natural sand, and 147 parts of coarse aggregate granite are used.

[0093] GGBS components include 38.47-41.78 wt % of CaO, 35.29-38.53 wt % of SiO.sub.2, 6.57-11.85 wt % of MgO, 8.17-11.41 wt % of Al.sub.2O.sub.3, 0.20-0.67 wt % of Fe.sub.2O.sub.3, 0.18-0.56 wt % of K.sub.2O, and 0.45-3.74 wt % of others.

[0094] Metakaolin components include 43.84-49.7 wt % of SiO.sub.2, 27.58-32.45 wt % of Al.sub.2O.sub.3, 7.25-9.78 wt % of K.sub.2O, 0.74-2.02 wt % of Fe.sub.2O.sub.3, and 7.29-15.47 wt % of others.

[0095] Fly ash components include 3.97-8.63 wt % of CaO, 45.20-48.34 wt % of SiO.sub.2, 23.71-31.10 wt % of Al.sub.2O.sub.3, 2.57-3.97 wt % of Na.sub.2O, 0.47-3.17 wt % of MgO, and 4.45-24.42 wt % of others.

Embodiment 6

[0096] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 6, the silicon-aluminum compounds are fly ash, and mass parts of the GGBS, the fly ash and the distilled water are 29, 18 and 4.7, respectively; and the mass part of aluminum oxide in the ball milling tank is 50.

[0097] When the slag concrete is prepared after the ball milling, 39 parts of Portland cement, 31 parts of water, 140 parts of fine aggregate natural sand, and 200 parts of coarse aggregate granite are used.

Embodiment 7

[0098] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 6, the silicon-aluminum compounds are metakaolin and fly ash, a ratio of metakaolin to fly ash is 1:1, and mass parts of the GGBS, the silicon-aluminum compounds and the distilled water are 31, 5 and 3.6; and the mass part of aluminum oxide in the ball milling tank is 50.

[0099] When the slag concrete is prepared after the ball milling, 35 parts of Portland cement, 25 parts of water, 127 parts of fine aggregate natural sand, and 190 parts of coarse aggregate granite are used.

Embodiment 8

[0100] A method for preparing concrete based on GGBS, silicon-aluminum compounds and CO.sub.2 waste gas is disclosed. As described in Embodiment 6, the untreated slag concrete without adding the silicon-aluminum compounds includes GGBS and Portland cement, mass parts of the GGBS, the Portland cement and the distilled water are 30, 35 and 26, the mass part of fine aggregate natural sand is 110, and the mass part of coarse aggregate granite is 160.

[0101] Compressive strength of the prepared concrete at 3d and 7d is tested according to GB-T 50081-2019 Standard for Test Methods of Concrete Physical and Mechanical Properties. The test results are as shown in table 1.

TABLE-US-00001 TABLE 1 Compressive strength of slag concrete at 7 d and 28 d Compressive strength Compressive strength Embodiments: at 7 d (MPa) at 7 d (MPa) Embodiment 5 45.74 55.51 Embodiment 6 41.17 53.16 Embodiment 7 42.28 54.35 Embodiment 8 38.50 46.71

[0102] Compared with the untreated concrete with the GGBS in Embodiment 8, the compressive strength of the slag concrete at 7d and 28d prepared in the present disclosure is improved by about 11.9% and 16.3% on average.

[0103] The compressive strength of the prepared concrete is tested according to GB-T50081-2019 Standard for Test Methods of Concrete Physical and Mechanical Properties. The mass of CO.sub.2 finally sequestrated in the GGBS mixture is calculated by an acid digestion method. 10% nitric acid solution is used for acid digestion, and a process of the acid digestion method is generally as follows: firstly, a weight of an empty beaker with a glass stick is recorded, about 40 g of GGBS mixture is weighed and put into the beaker, 300 ml of 10% nitric acid solution is put into another beaker, and the weight is recorded. The weighed nitric acid solution is mixed with the GGBS mixture, and stirred for 10 min with the glass stick (until bubbles disappear), and the weight of the mixture in the beaker is recorded. A CO.sub.2 sequestration rate is calculated by the following formula:

[00010]${\mathrm{CO}}_2=\frac{m_1+m_2-m_3}{m_1/\left(1+w_f\right)}*100,$

[0104] in the formula, m.sub.1 is the weight (about 40 g) of the weighed GGBS mixture; m.sub.2 is the weight (about 300 g) of the nitric acid solution; m.sub.3 is the weight of the mixture after being stirred continuously for 10 min; and we is a moisture content of the GGBS mixture. The sequestration rate is as shown in Table 2:

TABLE-US-00002 TABLE 2 CO.sub.2 sequestration rate of slag concrete Embodiments: Embodiment Embodiment 6 Embodiment 7 Sequestration rate 32.61 30.28 29.15 (%)

[0105] It can be seen that the CO.sub.2 sequestration rate in the present disclosure is relatively high, so that the industrial waste gas is utilized, and the concentration of CO.sub.2 in the atmosphere is reduced, which helps to slow down the greenhouse effect.

[0106] The above descriptions are preferred embodiments of the present disclosure. It should be pointed out that various improvements and modifications may be made by those ordinary skilled in the art without departing from the principle of the present disclosure. These improvements and modifications should also be regarded as the protection scope of the present disclosure.