Carbon dioxide enhanced plaster mortar and construction method thereof

Abstract

The present invention discloses a carbon dioxide-enhanced plaster mortar, comprising the following components by weight: 10 to 15 parts of cement, 10 to 18 parts of a carbonation enhancer, 120 to 140 parts of fine aggregate, 20 to 24 parts of mixing water, and 0.2 to 0.5 parts of an admixture; the carbonation enhancer is obtained by grinding carbide slag, steel slag, lithium slag, light-burned magnesium oxide, and magnesium sulfate as main raw materials. The present invention uses a large amount of industrial solid waste as raw materials and can maintain excellent working performance for a long time before construction. At the same time, after two plastering processes, a reinforcing liquid containing carbon dioxide is sprayed to quickly harden the plastered wall surface, significantly shortening the plastering construction interval. While improving construction efficiency, it ensures good bonding strength and compressive strength, and significantly reduces the carbon footprint of the mortar product. The present invention has significant economic and environmental benefits and is suitable for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a carbon dioxide enhanced plaster mortar and a construction method thereof. Background Art

[0002] The development and implementation of carbon dioxide capture, storage, and utilization (CCUS) in the building materials sector is becoming a research hotspot. However, existing research primarily focuses on the mineralization and utilization of CO2 in concrete products, with limited research on its application in building mortar products.

[0003] Patent CN114014619 discloses an air-carbonized mortar and a preparation method thereof, which utilizes the raw materials to adjust the mortar porosity and the high absorption rate of steel slag to CO2 to improve the carbonization ability of lime mortar in the atmosphere, thereby improving the compressive strength. Although this solution utilizes the raw materials in the mortar to carbonize carbon dioxide in the atmosphere, it is limited by the low carbon dioxide content in the atmosphere, and the carbonization rate and carbon fixation efficiency are limited, and it is impossible to achieve performance improvement in a short period of time. Patent CN111847999 discloses a reinforced mortar and a preparation method thereof, which achieves carbon dioxide fixation inside the mortar and accelerates carbonization by adding carbon dioxide-releasing resin balls into the mortar; however, after the resin balls release the carbon dioxide aqueous solution, their volume shrinks, forming pores between the interfaces, thereby affecting mechanical properties, etc.

[0004] Normally, the plastering work of a wall is divided into two plastering constructions. After the wall surface of the first plastering develops a certain strength, the second plastering construction is carried out. In order to ensure the working performance under long-term conditions, the existing premixed mortar (dry mix, wet mix mortar) needs to add a variety of admixtures. Although it meets the requirements of long-term working performance, the strength development is slow, which prolongs the interval time between the two plastering processes. Especially when the temperature is low, the construction workers need to wait for a long time for the wall surface to harden after the first plastering before they can carry out subsequent processes such as the second plastering, which greatly reduces the construction efficiency. For the mortar mixture that has not been constructed, during the long waiting process, even if a retarder is added, it will be affected by the ambient temperature and humidity, causing the consistency of the mortar mixture to gradually decrease until it hardens to the point where it is difficult to construct. If the retarder dosage is greatly increased to maintain the construction performance, the construction wall surface will harden slowly.

[0005] In order to resolve the contradiction between the need for premixed mortar to harden quickly after plastering on the wall and reduce the waiting time for secondary plastering, and the need for the unapplied mortar mixture to maintain excellent construction performance, and to further reduce the carbon footprint of mortar products, it is urgent to develop a mortar product that can maintain long-term construction performance before construction, harden quickly after plastering, and reduce carbon emissions and energy. Summary of the Invention

[0006] The main purpose of the present invention is to address the problems and shortcomings of existing plastering mortars and provide a carbon dioxide-enhanced plastering mortar and its construction method. It uses a large amount of industrial solid waste as raw materials and can maintain excellent working performance for a long time before construction. At the same time, after two plastering processes, a reinforcing liquid containing carbon dioxide is sprayed to quickly harden the plastered wall surface, greatly shortening the plastering construction interval. While improving construction efficiency, it ensures good bonding strength and compressive strength and significantly reduces the carbon footprint of the mortar product.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A carbon dioxide-enhanced plaster mortar comprises the following components in parts by mass: 10-15 parts of cement, 10-18 parts of a carbonation enhancer, 120-140 parts of fine aggregate, 20-24 parts of mixing water, and 0.2-0.5 parts of an admixture; the carbonation enhancer is obtained by grinding carbide slag, steel slag, lithium slag, light-burned magnesium oxide, and magnesium sulfate as main raw materials.

[0009] According to the above scheme, the strength of the cement is not less than grade 32.5.

[0010] According to the above scheme, the cement can be selected from one of silicate cement, ordinary silicate cement, composite silicate cement, fly ash silicate cement and slag silicate cement.

[0011] According to the above scheme, the specific surface area of ​​the carbonization strengthener is 300 to 400 m 2 / kg.

[0012] According to the above scheme, the mass ratio of carbide slag, steel slag, lithium slag, light-burned magnesium oxide and magnesium sulfate in the carbonization strengthener is (2-4):(1-3):(3-5):(0.7-0.9):(0.1-0.3).

[0013] Furthermore, the aforementioned carbide slag, steel slag, and lithium slag are derived waste products from the industrial production of acetylene, steelmaking, and lithium carbonate, respectively. Carbide slag is primarily composed of Ca(OH)2 and has a high alkalinity, with CaO accounting for 60-75% of its chemical composition. Steel slag contains large amounts of C3S, C2S, free CaO, and free MgO, with CaO accounting for 45-50%, Al2O3 accounting for 15-20%, and SiO2 accounting for 20-30%. Lithium slag is primarily composed of SiO2 and Al2O3, with SiO2 accounting for 50-60% and Al2O3 accounting for 15-20%. The alkaline carbonizable components contained in carbide slag and steel slag can significantly enhance the carbonization activity of the mortar. Furthermore, the highly alkaline environment provided by carbide slag and cement can stimulate the potential hydration activity of SiO2 and Al2O3 in the lithium slag and steel slag, thereby increasing the mortar's later strength. In addition, carbide slag, steel slag, lithium slag are ground together with light-burned magnesium oxide and magnesium sulfate. Magnesium oxide can destroy the amorphous network in the lithium slag under mechanical grinding, thereby improving the volcanic ash activity of the lithium slag. In the carbonization strengthener system obtained by grinding carbide slag, steel slag, lithium slag, light-burned magnesium oxide and magnesium sulfate, the ternary system of magnesium oxide, magnesium sulfate and water can react to form needle-shaped basic magnesium sulfate complex salt. After contacting carbon dioxide, the hydration product can further undergo carbonization reaction, thereby improving the mechanical properties of the system.

[0014] Furthermore, a grinding aid is introduced during the grinding process of the carbonized strengthening agent.

[0015] Furthermore, the grinding aid can be diethylene glycol or the like.

[0016] Furthermore, the amount of diethylene glycol used accounts for 0.03-0.06% of the total mass of carbide slag, steel slag, lithium slag, magnesium oxide and magnesium sulfate.

[0017] According to the above scheme, the fine aggregate is at least one of machine-made sand, natural sand, and tailings sand, with a moisture content of less than 1%, an MB value of less than 1.0g / kg, a fineness modulus of 2.2 to 2.6, and particles larger than 2.36mm account for less than 10%.

[0018] According to the above scheme, the active ingredients of the admixture include polycarboxylate water-reducing agent, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate, and the solid content is 30-40%.

[0019] Furthermore, the mass ratio of the polycarboxylate water-reducing agent, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate is (1-2):(0.2-0.4):(0.4-0.8):(0.1-0.3).

[0020] The present invention also provides a construction method of carbon dioxide enhanced plaster mortar, comprising the following steps:

[0021] (1) Cement, carbonation enhancer, fine aggregate, mixing water and admixture weighed according to the proportion are mixed evenly (60-90s) to obtain a mortar mixture, and the first plastering is performed;

[0022] (2) Using carbon dioxide gas as the carrier gas, spray the enhancement liquid on the first plastered wall;

[0023] (3) After waiting for 30 to 90 minutes, carry out the second plastering;

[0024] (4) Use carbon dioxide gas as carrier gas to spray the reinforcing liquid on the second plastered wall again, wait for 30 to 60 minutes, and then smooth it out;

[0025] (5) Let it stand for 24 to 36 hours, and then water it for curing to obtain the carbon dioxide-enhanced plaster mortar.

[0026] In the above scheme, in step (1), the thickness of the first plastering is 5 to 7 mm.

[0027] In the above scheme, in step (2), the concentration of the carbon dioxide gas source is 60-100 vol%.

[0028] In the above solution, the enhancement solution is a mixed solution of triethanolamine and diethanolamine with a concentration of 1-3%.

[0029] Furthermore, the mass ratio of triethanolamine to diethanolamine is (2-4):1; on the one hand, the weak alkalinity of the alcohol-amine mixed solution is utilized to absorb carbon dioxide; on the other hand, triethanolamine promotes the dissolution of C3A and C4AF in cement, accelerates their reaction with gypsum to form calcium sulfoaluminate, further promotes the hydration of C3S, and provides early strength growth for the mortar.

[0030] In the above scheme, during the spraying process of step (2), the nozzle pressure is 0.25-0.35 MPa, the nozzle flow rate is 180-240 mL / min, the spraying distance is 20-30 cm, and the spraying speed of the carbon dioxide enhancement liquid is 0.05-0.06 m 2 / s.

[0031] Furthermore, the spraying amount of the carbon dioxide enhancement liquid on the first plastering wall surface is 50-80 mL / m 2 .

[0032] In the above scheme, the thickness of the second plastering in step (3) is 8 to 15 mm.

[0033] In the above scheme, during the second spraying process in step (4), the nozzle pressure is 0.15-0.25 MPa, the nozzle flow rate is 150-180 mL / min, and the spraying distance is 30-40 cm; the spraying speed of the carbon dioxide enhancement liquid is 0.05-0.06 m2 / s.

[0034] Furthermore, the spraying amount of the carbon dioxide enhancement liquid on the second plastering wall surface is 42-60 mL / m 2 .

[0035] The plaster mortar prepared according to the above scheme significantly shortens the setting time after construction and improves the bonding and compressive properties while ensuring a 2-hour consistency loss. Compared with ordinary premixed plaster mortar, it greatly improves the construction efficiency of workers, improves the mechanical properties after hardening, and significantly reduces the carbon footprint of the mortar product. It has important economic and environmental benefits and is suitable for promotion and application.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The carbon footprint of mortar products is significantly reduced from two aspects: on the one hand, compared with ordinary cement mortar, the plastering mortar of the present invention utilizes carbonization reaction of carbon dioxide and alkali excitation enhancement effect to effectively improve mechanical properties, which can realize the resource utilization of a large amount of industrial solid waste and significantly reduce the amount of cement, with significant economic and environmental benefits; on the other hand, the mortar of the present invention can not only absorb the carbon dioxide introduced in the reinforcing liquid during construction to achieve carbon fixation, but the mortar after hardening can also continuously absorb carbon dioxide in the air, further reducing the carbon footprint of the mortar.

[0038] (2) The characteristic of carbon dioxide that makes carbon-fixing materials solidify and strengthen rapidly is utilized. After the first plastering, the present invention sprays a reinforcing liquid containing carbon dioxide during construction, and the wall surface hardens quickly, shortening the waiting time for the second plastering and greatly improving the construction efficiency. After the second plastering, the reinforcing liquid containing carbon dioxide is sprayed again to improve the density of the mortar finish wall surface, greatly enhancing the early strength of the plastering mortar. At the same time, there is no need to rely on the carbonization conditions in the traditional kettle, which can provide a new idea for the efficient carbonization process. In addition, the working performance of the mortar mixture that has not been sprayed is not affected, and it still maintains a workable consistency within 2 hours. Compared with ordinary premixed mortar, the mortar mixture of the present invention, combined with the construction process, has the advantages of not being hard when not in use and hardening quickly during construction.

[0039] (3) Improve the bonding performance of plaster mortar; use the injection pressure of the reinforcing liquid sprayed after the first plastering to form a small uneven state on the wall surface of the first plastering, increase the roughness of the plastering surface, which is more conducive to the adhesion of the second plastering surface and can promote the improvement of the bonding strength between the two mortar layers. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the purpose, technical solutions and beneficial effects of the present invention, the present invention will now be described in detail with reference to specific embodiments.

[0041] In the following examples, the performance of the obtained mortar was tested using the following method:

[0042] With reference to "Ready-Mixed Mortar" (GB / T 25181-2019) and "Standard for Test Methods for Basic Properties of Building Mortar" (JGJ / T70-2009), the mortar was tested for its 2-hour consistency loss rate, setting time, 14-day tensile bond strength, and compressive strength. The 2-hour consistency loss rate refers to the change in consistency after the mortar mixture has been left unplastered for 2 hours. The setting time and compressive strength test pieces were sampled and formed after the specified construction method was completed. The 14-day tensile bond strength test was a physical test.

[0043] In the following examples, CaO accounted for 65% in the carbide slag chemical composition; CaO accounted for 48%, Al2O3 accounted for 16%, and SiO2 accounted for 24% in the steel slag; SiO2 accounted for 53% and Al2O3 accounted for 17% in the lithium slag.

[0044] In the following examples, the alcoholamine mixed solution used is a 2% triethanolamine / diethanolamine mixed aqueous solution, wherein the mass ratio of triethanolamine to diethanolamine is 3:1.

[0045] Example 1

[0046] A carbon dioxide enhanced plaster mortar, the components and their weight percentages are: 10 parts of cement, 15 parts of carbonation enhancer, 140 parts of fine aggregate, 20 parts of mixing water, and 0.2 parts of admixture;

[0047] Among them, the cement used is 42.5 grade ordinary Portland cement;

[0048] The carbonization strengthening agent used is made by grinding dried carbide slag, steel slag, lithium slag, light-burned magnesium oxide, magnesium sulfate and diethylene glycol together to a specific surface area of ​​400m 2 / kg obtained; wherein, the mass ratio of carbide slag, steel slag, lithium slag, light-burned magnesium oxide and magnesium sulfate is 2:1:3:0.7:0.3, and the amount of diethylene glycol accounts for 0.04% of the total mass of carbide slag, steel slag, lithium slag, magnesium oxide and magnesium sulfate;

[0049] The fine aggregate used is machine-made sand with a moisture content of 0.6%, MB value of 0.5g / kg, and fineness modulus of 2.6, of which particles larger than 2.36mm account for 8%;

[0050] The active ingredients of the admixture used include polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate, with a solid content of 30%; wherein the mass ratio of polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate is 2:0.3:0.4:0.1;

[0051] The construction method of the carbon dioxide enhanced plaster mortar comprises the following steps:

[0052] (1) Cement, carbonation enhancer, fine aggregate, mixing water and admixture weighed according to the proportion were mixed and stirred for 70 seconds to obtain a mortar mixture. The first plastering was performed on the wall surface that had been cleaned, pre-wetted and roughened, with a plastering thickness of 5 mm.

[0053] (2) Using a 100% carbon dioxide gas source as the carrier gas, spray a 2% alcohol amine mixed solution on the first plastered wall, wherein the nozzle pressure is adjusted to 0.25 MPa, the nozzle flow rate is 240 mL / min and the spraying distance is 30 cm. The alcohol amine mixed solution is sprayed at 0.05 m 2 / s speed evenly spray on the first plastering wall, spraying volume 80mL / m 2 ;

[0054] (3) After waiting for 30 minutes, perform secondary wall plastering with a thickness of 15 mm;

[0055] (4) With a carbon dioxide gas source with a concentration of 100% as the carrier gas, adjust the spray nozzle pressure to 0.25MPa, the nozzle flow rate to 180mL / min and the spray distance to 40cm again, and spray the 2% alcohol amine mixed solution at 0.05m 2 / s speed on the secondary plastered wall, spraying volume is 60mL / m 2 After 30 minutes, smooth the plastered wall surface;

[0056] (5) After 24 hours, the plastered wall surface is watered and cured; after curing, carbon dioxide enhanced plaster mortar is obtained.

[0057] Example 2

[0058] A carbon dioxide enhanced plaster mortar, the components and their weight percentages are: 15 parts of cement, 18 parts of carbonation enhancer, 125 parts of fine aggregate, 24 parts of mixing water, and 0.5 parts of admixture;

[0059] Among them, the cement used is 32.5 grade slag Portland cement;

[0060] The carbonization strengthening agent used is made by grinding dried carbide slag, steel slag, lithium slag, light-burned magnesium oxide, magnesium sulfate and diethylene glycol together to a specific surface area of ​​300m 2 / kg obtained; wherein, the mass ratio of carbide slag, steel slag, lithium slag, light-burned magnesium oxide and magnesium sulfate is 2:3:5:0.9:0.3, and the amount of diethylene glycol accounts for 0.03% of the total mass of carbide slag, steel slag, lithium slag, magnesium oxide and magnesium sulfate;

[0061] The fine aggregate used is natural sand with a moisture content of 0.5%, MB value of 0.8g / kg, and fineness modulus of 2.4, of which particles larger than 2.36mm account for 5%;

[0062] The active ingredients of the admixture used include polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate, with a solid content of 35%; wherein the mass ratio of polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate is 2:0.2:0.5:0.2;

[0063] The construction method of the carbon dioxide enhanced plaster mortar comprises the following steps:

[0064] (1) Cement, carbonation enhancer, fine aggregate, mixing water and admixture weighed according to the proportion were mixed and stirred for 90 seconds to obtain a mortar mixture. The first plastering was performed on the wall surface that had been cleaned, pre-wetted and roughened, with a plastering thickness of 7 mm.

[0065] (2) Using a 60% carbon dioxide gas source as the carrier gas, spray a 2% alcohol amine mixed solution on the first plastered wall, wherein the nozzle pressure is adjusted to 0.35MPa, the nozzle flow rate is 240mL / min and the spraying distance is 20cm. The alcohol amine mixed solution is sprayed at 0.06m 2 / s speed evenly spray on the first plastering wall, spraying volume is 67mL / m 2 ;

[0066] (3) After waiting for 90 minutes, perform secondary wall plastering with a thickness of 10 mm;

[0067] (4) With a carbon dioxide gas source with a concentration of 60% as the carrier gas, adjust the spray nozzle pressure to 0.25MPa, the nozzle flow rate to 150mL / min and the spray distance to 30cm again, and spray the 2% alcohol amine mixed solution at 0.06m 2 / s speed on the secondary plastered wall, spraying the second time, the spraying volume is 42mL / m 2 After 60 minutes, smooth the plastered wall surface;

[0068] (5) After 24 hours, the plastered wall surface is watered and cured; after curing, carbon dioxide enhanced plaster mortar is obtained.

[0069] Example 3

[0070] A carbon dioxide enhanced plaster mortar, the components and their weight percentages are: 14 parts of cement, 14 parts of carbonization enhancer, 130 parts of fine aggregate, 220 parts of mixing water, and 0.3 parts of admixture;

[0071] Among them, the cement used is 42.5 grade composite Portland cement;

[0072] The carbonization strengthening agent used is made by grinding dried carbide slag, steel slag, lithium slag, light-burned magnesium oxide, magnesium sulfate and diethylene glycol together to a specific surface area of ​​350m 2 / kg obtained; wherein, the mass ratio of carbide slag, steel slag, lithium slag, light-burned magnesium oxide and magnesium sulfate is 3:2:5:0.8:0.2, and the amount of diethylene glycol accounts for 0.04% of the total mass of carbide slag, steel slag, lithium slag, magnesium oxide and magnesium sulfate;

[0073] The fine aggregate used is a mixture of machine-made sand and tailings sand, with a moisture content of 0.8%, MB value of 0.6g / kg, fineness modulus of 2.2, of which particles larger than 2.36mm account for 5%;

[0074] The active ingredients of the admixture used include polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate, with a solid content of 40%; wherein the mass ratio of polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate is 1:0.2:0.4:0.2;

[0075] The construction method of the carbon dioxide enhanced plaster mortar comprises the following steps:

[0076] (1) Cement, carbonation enhancer, fine aggregate, mixing water and admixture weighed according to the proportion are mixed and stirred for 60 seconds to obtain a mortar mixture, and the first plastering is performed on the wall surface that has been cleaned, pre-wetted and roughened, with a plastering thickness of 5 mm;

[0077] (2) Using 80% carbon dioxide gas as carrier gas, spray a 2% alcohol amine mixed solution on the first plastered wall, wherein the nozzle pressure is adjusted to 0.3MPa, the nozzle flow rate is 200mL / min and the spraying distance is 30cm. The alcohol amine mixed solution is sprayed at 0.05m 2 / s speed evenly spray on the first plastering wall, spraying volume is 67mL / m 2 ;

[0078] (3) After waiting for 60 minutes, perform secondary wall plastering with a thickness of 10 mm;

[0079] (4) With 80% carbon dioxide gas as carrier gas, adjust the spray nozzle pressure to 0.2MPa, nozzle flow rate to 180mL / min and spray distance to 40cm again, and spray the 2% alcohol amine mixed solution at 0.05m 2 / s speed on the secondary plastered wall, spraying volume 60mL / m 2 After 40 minutes, smooth the plastered wall surface;

[0080] (5) After 36 hours, the plastered wall surface is watered and cured; after the curing is completed, the carbon dioxide enhanced plaster mortar is obtained.

[0081] Comparative Example 1

[0082] A carbon dioxide-enhanced plaster mortar, the formula and construction method of which differ from those of Example 1 only in that the carbonization enhancer is replaced by S95 mineral powder of the same mass.

[0083] Comparative Example 2

[0084] A carbon dioxide enhanced plaster mortar, the formula and construction method of which differ from those of Example 2 only in that the alcohol amine mixed solution in step (2) is replaced by tap water.

[0085] Comparative Example 3

[0086] A carbon dioxide enhanced plaster mortar, the formula and construction method of which differ from those of Example 3 only in that the carbon dioxide gas source in construction step (3) is replaced by air.

[0087] Comparative Example 4

[0088] A carbon dioxide-enhanced plaster mortar, the formula and construction method of which differ from those of Example 1 only in that light-burned magnesium oxide and magnesium sulfate are not added to the carbonization strengthener.

[0089] Comparative Example 5

[0090] A carbon dioxide-enhanced plaster mortar, the formula and construction method of which differ from those of Example 1 only in that light-burned magnesium oxide and magnesium sulfate are not added to the carbonization strengthener, but equal amounts of light-burned magnesium oxide and magnesium sulfate are added during the stirring process in step (1).

[0091] The test results of 2h consistency loss rate, setting time, 14d tensile bond strength and compressive strength of the mortars described in Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 1, respectively.

[0092] Table 1 Performance test results of the mortars described in Examples 1 to 3 and Comparative Examples 1 to 5:

[0093]

[0094] The above performance test results show that the setting time, 14-day tensile bond strength, and compressive strength of the CO2-enhanced plaster mortars of Examples 1 to 3 are significantly superior to those of Comparative Examples 1 to 5. While maintaining a 2-hour consistency loss, the CO2-enhanced plaster mortar of the present invention significantly shortens the post-construction setting time and improves bonding and compressive properties. Compared to conventional premixed plaster mortars, this significantly increases worker efficiency, improves mechanical properties after hardening, and significantly reduces the carbon footprint of the mortar product.

[0095] The above describes the embodiments of the present invention, but the present invention is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A construction method for carbon dioxide enhanced plaster mortar, characterized in that: The steps include: (1) Mix cement, carbonation enhancer, fine aggregate, mixing water and admixtures weighed according to the proportion to obtain a mortar mixture, and perform the first plastering; (2) Using carbon dioxide gas as the carrier gas, spray the reinforcing liquid onto the first plastered wall; (3) After waiting for 30 to 90 minutes, carry out the second plastering; (4) Use carbon dioxide gas as the carrier gas to spray the reinforcing liquid on the second plastered wall again, wait for 30 to 60 minutes, and then smooth it out; (5) Standing and water curing to obtain carbon dioxide enhanced plaster mortar; The carbon dioxide enhanced plaster mortar comprises the following components in parts by weight: 10-15 parts of cement, 10-18 parts of carbonization enhancer, 120-140 parts of fine aggregate, 20-24 parts of mixing water, and 0.2-0.5 parts of admixture; the carbonization enhancer is obtained by grinding carbide slag, steel slag, lithium slag, light-burned magnesium oxide, and magnesium sulfate as main raw materials; The enhancement solution is a mixed solution of triethanolamine and diethanolamine.

2. The construction method of carbon dioxide enhanced plaster mortar according to claim 1, characterized in that: In the carbonization strengthener, the mass ratio of carbide slag, steel slag, lithium slag, light-burned magnesium oxide, and magnesium sulfate is (2-4): (1-3): (3-5): (0.7-0.9): (0.1-0.3).

3. The construction method of carbon dioxide enhanced plaster mortar according to claim 1, characterized in that: The specific surface area of ​​the carbonization strengthener is 300~400m 2 / kg.

4. The construction method of carbon dioxide enhanced plaster mortar according to claim 1, characterized in that: The fine aggregate is at least one of machine-made sand, natural sand, and tailings sand, with a moisture content of less than 1%, an MB value of less than 1.0 g / kg, a fineness modulus of 2.2 to 2.6, and particles larger than 2.36 mm accounting for less than 10%.

5. The construction method of carbon dioxide enhanced plaster mortar according to claim 1, characterized in that: The active ingredients of the admixture include polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate.

6. The construction method of carbon dioxide enhanced plaster mortar according to claim 5, characterized in that: The mass ratio of the polycarboxylate water reducer, hydroxypropyl methylcellulose, sodium lauryl sulfate and sodium gluconate is (1-2): (0.2-0.4): (0.4-0.8): (0.1-0.3).

7. The construction method according to claim 1, characterized in that: During the spraying process of step (2), the nozzle pressure is 0.25~0.35MPa, the nozzle flow rate is 180~240mL / min, the spraying distance is 20~30cm, and the enhancement liquid spraying speed is 0.05~0.06m 2 / s, spraying volume is 50~80mL / m 2 During the second spraying process in step (4), the nozzle pressure is 0.15~0.25MPa, the nozzle flow rate is 150~180mL / min, and the spraying distance is 30~40cm; the spraying speed of the enhancement liquid is 0.05~0.06m 2 / s, spraying volume is 42~60mL / m 2 .

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