Baking-free brick curing agent, super-early-strength muck-based baking-free brick and preparation method of baking-free brick

Abstract

The invention relates to the technical field of geotechnical engineering and constructional engineering, in particular to a baking-free brick curing agent, a super-early-strength muck-based baking-free brick and a preparation method thereof.The baking-free brick curing agent is prepared from, by mass, 76-80 parts of mineral powder, 8-10 parts of quick lime, 2-3 parts of fly ash, 4.5-4.9 parts of desulfurized gypsum, 4.5-4.9 parts of sulfur-aluminum cement, 1-1.5 parts of nano-silicon dioxide and 0.1-0.3 part of lithium carbonate; and 0.1-0.3 part of a naphthalene water reducer. The raw materials of the super-early-strength muck-based baking-free brick comprise muck and the baking-free brick curing agent. According to the invention, the baking-free brick curing agent is added into the muck in a grading manner to prepare the super-early-strength muck-based baking-free brick, and the brick does not need to be specially cured and can reach the design strength within 8 hours under natural conditions; the method overcomes the defect that a lot of time and a lot of stacking sites need to be consumed for maintenance after pressing is completed in an existing baking-free brick preparation technology, meanwhile, high-temperature calcination is not needed, engineering waste is utilized, and the production cost of the baking-free brick is reduced.

Description

Technical Field

[0001] The present invention relates to the technical fields of geotechnical engineering and construction engineering, and specifically relates to a non-fired brick curing agent, an ultra-early-strength muck-based non-fired brick, and a preparation method thereof. Background Art

[0002] With the rapid advancement of the urbanization process and the continuous development of urban renewal projects, a huge amount of construction waste is generated during the construction of new or renovated engineering projects. As a typical representative, muck includes foundation pit muck, shield muck, and various construction wastes, etc., and its output shows a sharp growth trend. The proper treatment and resource utilization of muck have become urgent environmental and development issues. Against this background, the technical route of using muck to prepare non-fired building materials has emerged.

[0003] The resource utilization of muck to prepare non-fired building materials uses muck as the core raw material, supplemented by appropriate cementitious materials, and forms new building materials through processes such as mixing, pressing, and curing. The mechanical properties, durability, and carbon emission indicators of such non-fired building materials largely depend on the specific types and mix ratios of the materials.

[0004] Currently, there have been many studies on the preparation of non-fired bricks. For example, CN106630801A discloses a method for preparing non-fired bricks: first, black cotton soil and volcanic ash are crushed, then the crushed black cotton soil, volcanic ash, cement, and calcium hydroxide are formed into a mixture according to a specific ratio and ground evenly, then water is added and stirred to form a mixed material, and then the mixed material is pressed into shape, and the initial blank is obtained through room-temperature aging, and then the initial blank is placed in a steam curing kettle for curing, and finally cooled to room temperature to obtain non-fired bricks. The non-fired bricks prepared by this method show the advantages of high strength and low water absorption, and have the potential to become widely used engineering building materials.

[0005] CN105669071A discloses an efficient activator for non-fired bricks. Its raw materials by weight include: 15-25 parts of dodecylnaphthalenesulfonic acid sodium, 5-15 parts of dodecylbenzenesulfonic acid sodium, 5-15 parts of diisooctyldiphenylamine, 8-12 parts of dibutyl phosphite, 25-35 parts of metasilicate, 20-30 parts of sodium sulfate, and 10-20 parts of potassium carbonate. This activator can strongly stimulate SiO2 and Al2O3 in slag and fly ash to form clinker, greatly save the amount of cement used, increase the utilization ratio of slag and fly ash, and thus reduce the production cost of non-fired brick blocks. At the same time, it can also significantly improve the compressive strength of non-fired brick blocks. Its excellent performance stems from the synergistic effect of diisooctyldiphenylamine and dibutyl phosphite.

[0006] CN118388182A discloses a composition for preparing unburned bricks and a corresponding method for preparing unburned bricks, which belongs to the category of solid waste recycling technology. The composition is composed of 25-30 parts of coal powder slag, 22-26 parts of ceramic waste slag, 13-17 parts of blast furnace slag, 10-13 parts of cement, 8-11 parts of emulsified asphalt, 2-4 parts of gypsum fiber, 2-4 parts of polycarboxylic acid coagulant, 1.5-3 parts of diisooctyl sebacate, 1-2 parts of anionic surfactant, and 4-7 parts of water, based on a total of 100 parts by weight. The unburned bricks obtained by mixing the raw materials of the composition into mixed dry materials and mixed emulsions, and then mixing, pressing, curing and other processes have excellent compressive strength and anti-freezing properties.

[0007] However, it is not difficult to find that the existing patent technology has many limitations. On the one hand, after the unburned bricks are pressed, they generally need to be cured at high temperature or rely on natural curing, which not only takes a lot of time, but also takes up a spacious stacking area, greatly pushing up the production cost of unburned bricks and weakening their market competitiveness. On the other hand, the additives in the above patents are various and expensive, which makes the production cost high. At the same time, the utilization ratio of inorganic solid waste is limited, and it is difficult to give full play to the resource value of solid waste materials such as slag. There is still significant room for improvement in reducing carbon emissions and realizing the deep utilization of solid waste materials. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides an unburned brick curing agent, an ultra-early strength slag-based unburned brick and a preparation method thereof. The slag-based unburned brick added with the unburned brick curing agent can achieve the design strength requirements within 8 hours under natural curing conditions.

[0009] In order to achieve the above object, the present invention provides:

[0010] A curing agent for unburned bricks, comprising a curing agent A and a curing agent B; in parts by mass, the curing agent A comprises 76-80 parts of mineral powder, 8-10 parts of quicklime, 2-3 parts of fly ash, 4.5-4.9 parts of desulfurized gypsum, and 4.5-4.9 parts of sulfoaluminum cement; the curing agent B comprises 1-1.5 parts of nano silicon dioxide, 0.1-0.3 parts of lithium carbonate, and 0.1-0.3 parts of naphthalene-based water reducer.

[0011] Furthermore, the curing agent A includes 76-79 parts of mineral powder, 8-9 parts of quicklime, 2-2.5 parts of fly ash, 4.8-4.9 parts of desulfurized gypsum, and 4.8-4.9 parts of sulfoaluminum cement; the curing agent B includes 1-1.2 parts of nano-silicon dioxide, 0.1-0.2 parts of lithium carbonate, and 0.1-0.2 parts of naphthalene-based water reducer.

[0012] Further, the curing agent A comprises 79 parts of mineral powder, 8 parts of quicklime, 2 parts of fly ash, 4.9 parts of desulfurized gypsum, and 4.9 parts of sulphoaluminate cement; the curing agent B comprises 1 part of nano-silica, 0.1 part of lithium carbonate, and 0.1 part of naphthalene series water reducer.

[0013] Further, the fly ash is high-calcium fly ash.

[0014] Further, the naphthalene series water reducer is at least one of FDN water reducer, UNF water reducer, NF water reducer, and HN water reducer.

[0015] On the other hand, the present invention provides a super-early-strength muck-based non-fired brick, and the raw materials of the super-early-strength muck-based non-fired brick comprise muck and the above-mentioned non-fired brick curing agent.

[0016] Further, by mass percentage, the muck is 70% - 80%, and the non-fired brick curing agent is 20% - 30%.

[0017] Further, the particle size of the muck is less than or equal to 2 mm.

[0018] Further, the muck is at least one of tunnel shield muck, pile foundation engineering muck, earthwork engineering muck, and demolition engineering muck.

[0019] The present invention also provides a preparation method of a super-early-strength muck-based non-fired brick, comprising the following steps:

[0020] Crush the muck to a particle size less than or equal to 2 mm for standby;

[0021] Prepare the non-fired brick curing agent A: mix mineral powder, quicklime, fly ash, desulfurized gypsum, and sulphoaluminate cement powder;

[0022] Add the non-fired brick curing agent A to the crushed muck, mix evenly, and stir for 3 - 5 minutes to obtain powder material 1;

[0023] Prepare the non-fired brick curing agent B: mix nano-silica, lithium carbonate, and naphthalene series water reducer powder;

[0024] Add the non-fired brick curing agent B to the powder material 1, mix evenly, and stir for 2 minutes to obtain powder material 2;

[0025] Add water to the powder material 2, and the mass percentage of the water in the powder material 2 is 20% - 22%, stir evenly to obtain a mixed wet material;

[0026] Form the mixed wet material into brick blanks;

[0027] Naturally cure for 8 hours to obtain a super-early-strength muck-based non-fired brick.

[0028] Furthermore, the brick blanks are formed by a press under double-sided pressing, and are pressed for 60 s under a double-sided pressure of 10 Mpa to 20 Mpa.

[0029] Furthermore, the double-sided pressing is carried out by raising the pressure to 10 Mpa and pressing for 10 s, raising the pressure to 15 Mpa and pressing for 20 s, and raising the pressure to 20 Mpa and pressing for 30 s.

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) Significantly improve the early strength and construction efficiency

[0032] (1) By selecting raw materials and designing specific ratios, the prepared non-fired brick curing agent can greatly shorten the natural curing time required for the slag-based non-fired bricks to reach the designed strength. In this non-fired brick curing agent, calcium hydroxide generated by quicklime reacting with water creates a highly alkaline environment, effectively accelerating the pozzolanic reaction of mineral powder and fly ash and the hydration process of sulfoaluminate cement; lithium carbonate acts as a catalyst, synergistically with the alkaline environment to further accelerate the hydration reaction of each component, promoting the formation of more hydration products. These hydration products are intertwined to form a dense network structure, significantly improving the early strength of the brick body. At the same time, lithium carbonate can activate the activity of the slag. The alkaline conditions provided by lithium carbonate can activate active components such as silicate and aluminate in the slag to react with the hydration products for a secondary reaction, generating more gel substances; enhancing the structural strength of the non-fired bricks; and moreover, by studying and controlling the ratio of lithium carbonate to the components generating the hydration reaction, the present invention effectively controls the setting and hardening time of the brick body. While ensuring that the brick blanks of the non-fired bricks have a certain initial strength in a short time, facilitating the subsequent demolding and handling processes, it overcomes quality problems such as internal structural defects and uneven strength caused by premature gelation. At the same time, nano-silica fills the pores of the brick body with its extremely small particle size, and ettringite generated by the reaction of desulfurized gypsum and cement fills the pores through expansion, making the brick body more dense. Naphthalene-based water reducer reduces the water-cement ratio and reduces the pores formed in the brick body due to the evaporation of excess water. Through the synergistic effect of these components, the density, strength and impermeability of the brick body are comprehensively improved, and the early strength performance is extremely prominent. The compressive strength can reach more than 10 MPa after 8 hours, and the strength after 1 day exceeds 20 MPa, which is more than 200% higher than the conventional process, greatly shortening the brick hardening time, enabling transportation and use after 8 hours, greatly reducing the site occupation area and time, and significantly improving the construction efficiency.

[0033] (2) High solid waste utilization rate and environmental protection and energy saving advantages

[0034] While achieving high performance of the construction waste-based non-fired bricks, the present invention also has an extremely high solid waste utilization rate. The content of construction waste in the brick body reaches more than 70% by mass, and the proportion of solid waste used in the curing agent exceeds 80%, fully reflecting the effective utilization of solid waste and conforming to the environmental protection concept. In addition, this technology does not require a sintering process, reducing energy consumption by 90%, effectively reducing energy consumption and environmental pollution. At the same time, this technology is applicable to the direct utilization of various engineering construction wastes without complex pretreatment steps, further improving the resource utilization efficiency. In terms of curing, it only needs natural curing under normal temperature conditions to reach the design strength without harsh high-temperature and high-pressure conditions, reducing production costs and energy consumption, and having good environmental protection and energy-saving advantages.

[0035] (3) Excellent durability and cost-effectiveness

[0036] The construction waste-based non-fired bricks prepared by the present invention not only have high early strength but also excellent durability. After 20 freeze-thaw cycles, the strength loss rate of the brick body does not exceed 10%; after 20 dry-wet cycles, the strength loss rate does not exceed 15%. Compared with traditional cement bricks, its durability is better. This benefits from the dense network structure inside the brick body, the dense pore distribution, and good impermeability. In addition, the cost of the curing agent is 30% lower than that of traditional cement, and the savings in site occupation area and time also bring a significant reduction in cost, having broad application prospects and remarkable economic benefits. Description of the Drawings

[0037] Figure 1 is the process flow chart for the preparation of construction waste-based non-fired bricks;

[0038] Figure 2 is the performance comparison chart of the construction waste-based non-fired bricks prepared in Example 1 of the present invention and Comparative Examples 1-3;

[0039] Figure 3 is the long-term durability test result chart of the construction waste-based non-fired bricks prepared in Example 1 of the present invention;

[0040] Figure 4 is the cost comparison chart for treating 1 ton of construction waste;

[0041] Figure 5 is the cost comparison chart of the curing agent of the present invention and PO42.5 cement required for preparing 1 standard-sized non-fired brick. Detailed Embodiments

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0043] Unless otherwise specified, the materials used in the embodiments of the present invention can be obtained through commercial channels or prepared by conventional methods well-known to those skilled in the art.

[0044] The present invention provides a non-fired brick curing agent, which includes curing agent A and curing agent B; by mass, the curing agent A includes 76 - 80 parts of mineral powder, 8 - 10 parts of quicklime, 2 - 3 parts of fly ash, 4.5 - 4.9 parts of desulfurized gypsum, and 4.5 - 4.9 parts of sulfoaluminate cement; the curing agent B includes 1 - 1.5 parts of nano-silica, 0.1 - 0.3 parts of lithium carbonate, and 0.1 - 0.3 parts of naphthalene-based water reducing agent.

[0045] The present invention also provides an ultra-early-strength soil-based non-fired brick, which includes, by mass percentage, 70% - 80% of soil and 20% - 30% of the above non-fired brick curing agent.

[0046] The preparation method of the ultra-early-strength soil-based non-fired brick of the present invention is as Figure 1 shown, specifically:

[0047] Crush the soil to a particle size less than or equal to 2 mm for standby;

[0048] Prepare the non-fired brick curing agent A: Mix the mineral powder, quicklime, fly ash, desulfurized gypsum, and sulfoaluminate cement powder;

[0049] Add the non-fired brick curing agent A to the crushed soil and mix evenly, stir for 3 - 5 minutes to obtain powder 1;

[0050] Prepare the non-fired brick curing agent B: Mix the nano-silica, lithium carbonate, and naphthalene-based water reducing agent powder;

[0051] Add the non-fired brick curing agent B to the powder 1 and mix evenly, stir for 2 minutes to obtain powder 2;

[0052] Add water to the powder 2, and the mass percentage of water in the powder 2 is 20% - 22%, stir evenly to obtain a mixed wet material;

[0053] Form the mixed wet material into brick blanks;

[0054] Naturally cure for 8 hours to obtain an ultra-early-strength soil-based non-fired brick.

[0055] To more clearly illustrate the technical solution and advantages of the present invention, the present invention will be further explained below in conjunction with examples and comparative examples.

[0056] Example 1

[0057] A super-early-strength muck-based non-fired brick, with raw materials being 7 kg of shield muck, 2.964 kg of non-fired brick curing agent A, and 0.036 kg of non-fired brick curing agent B; among them, non-fired brick curing agent A consists of 2.37 kg of mineral powder, 0.24 kg of quicklime, 0.06 kg of fly ash, 0.147 kg of desulfurized gypsum, and 0.147 kg of sulfoaluminate cement; non-fired brick curing agent B consists of 0.03 kg of nano-silica, 0.003 kg of lithium carbonate, and 0.003 kg of naphthalene-based water reducer.

[0058] The preparation method of the super-early-strength muck-based non-fired brick includes the following steps:

[0059] Take 7 kg of shield muck, dry it, crush it to less than 2 mm, and set aside;

[0060] Take 2.37 kg of mineral powder, 0.24 kg of quicklime, 0.06 kg of fly ash, 0.147 kg of desulfurized gypsum, and 0.147 kg of sulfoaluminate cement, and mix and prepare non-fired brick curing agent A;

[0061] Dry-mix the prepared non-fired brick curing agent A with the muck and stir for 5 minutes to obtain powder 1;

[0062] Take 0.03 kg of nano-silica, 0.003 kg of lithium carbonate, and 0.003 kg of naphthalene-based water reducer, and mix and prepare non-fired brick curing agent B;

[0063] Add the above-prepared non-fired brick curing agent B to the powder 1, mix evenly, and stir for 2 minutes to obtain powder 2;

[0064] Add 2 kg of water to the above powder 2 and stir evenly;

[0065] Pour the mixture into a brick mold pre-coated with a release agent, and press it with a two-way press for 60 seconds, applying in three stages, namely 0 → 10 MPa (10 s) → 15 MPa (20 s) → 20 MPa (30 s), to obtain a brick blank;

[0066] Place the brick blank on the open ground for natural curing without other covering on the upper part, and the super-early-strength muck-based non-fired brick can be obtained after 8 hours.

[0067] The compressive strength of the non-fired brick prepared in this example was tested, and the 8-hour compressive strength was measured to be 11.3 MPa, and the 24-hour compressive strength was 21.2 MPa.

[0068] Example 2

[0069] A super-early-strength soil-cement-based non-fired brick, with raw materials including 8 kg of shield construction waste, 1.96 kg of non-fired brick curing agent A, and 0.042 kg of non-fired brick curing agent B; among them, non-fired brick curing agent A consists of 1.52 kg of mineral powder, 0.20 kg of quicklime, 0.06 kg of fly ash, 0.09 kg of desulfurized gypsum, and 0.088 kg of sulphoaluminate cement; non-fired brick curing agent B consists of 0.03 kg of nano-silica, 0.006 kg of lithium carbonate, and 0.006 kg of naphthalene-based water reducer.

[0070] The preparation method of the super-early-strength soil-cement-based non-fired brick includes the following steps:

[0071] Take 8 kg of shield construction waste, dry it, and crush it to less than 2 mm for standby;

[0072] Take 1.52 kg of mineral powder, 0.20 kg of quicklime, 0.06 kg of fly ash, 0.09 kg of desulfurized gypsum, and 0.088 kg of sulphoaluminate cement, and mix them to prepare non-fired brick curing agent A;

[0073] Dry-mix the prepared non-fired brick curing agent A with the soil and stir for 5 minutes to obtain powder 1;

[0074] Take 0.03 kg of nano-silica, 0.006 kg of lithium carbonate, and 0.006 kg of naphthalene-based water reducer, and mix them to prepare non-fired brick curing agent B;

[0075] Add the above-prepared non-fired brick curing agent B to the powder 1, mix evenly, and stir for 2 minutes to obtain powder 2;

[0076] Add 2 kg of water to the above powder 2 and stir evenly;

[0077] Pour the mixture into a brick mold pre-coated with a release agent, and press it with a two-way press for 60 seconds, applying in three stages: 0 → 10 MPa (10 s) → 15 MPa (20 s) → 20 MPa (30 s) to obtain a brick blank;

[0078] Place the brick blank on the ground for natural curing without other covering on the top, and the super-early-strength soil-cement-based non-fired brick can be obtained after 8 hours.

[0079] Conduct a compressive strength test on the non-fired brick prepared in this example, and the measured compressive strength at 8 h is 10.9 MPa, and the compressive strength at 24 h is 20.5 MPa.

[0080] Example 3

[0081] A super-early-strength brick made of construction waste soil without firing, with the raw materials being 7.5 kg of foundation pit construction waste soil, 2.42 kg of non-firing brick curing agent A, and 0.04 kg of non-firing brick curing agent B; among them, non-firing brick curing agent A consists of 1.94 kg of mineral powder, 0.18 kg of quicklime, 0.06 kg of fly ash, 0.12 kg of desulfurized gypsum, and 0.12 kg of sulphoaluminate cement; non-firing brick curing agent B consists of 0.03 kg of nano-silica, 0.005 g of lithium carbonate, and 0.005 g of naphthalene-based water reducer.

[0082] The preparation method of the super-early-strength brick made of construction waste soil without firing includes the following steps:

[0083] Take 7.5 kg of shield construction waste soil, dry it, and crush it to less than 2 mm for standby;

[0084] Take 1.94 kg of mineral powder, 0.18 kg of quicklime, 0.06 kg of fly ash, 0.12 kg of desulfurized gypsum, and 0.12 kg of sulphoaluminate cement, and mix them to prepare non-firing brick curing agent A;

[0085] Dry-mix the prepared non-firing brick curing agent A with the construction waste soil and stir for 5 minutes to obtain powder 1;

[0086] Take 0.03 kg of nano-silica, 0.005 kg of lithium carbonate, and 0.005 kg of naphthalene-based water reducer, and mix them to prepare non-firing brick curing agent B;

[0087] Add the above-mentioned non-firing brick curing agent B to the powder 1, mix evenly, and stir for 2 minutes to obtain powder 2;

[0088] Add 2.2 kg of water to the above-mentioned powder 2 and stir evenly;

[0089] Pour the mixture into a brick mold pre-coated with a release agent, and press it with a two-way press for 60 seconds, applying in three stages, namely 0 → 10 MPa (10 s) → 15 MPa (20 s) → 20 MPa (30 s), to obtain a brick blank;

[0090] Place the brick blank on the ground for natural curing without other covering on the upper part, and the super-early-strength brick made of construction waste soil without firing can be obtained after 8 hours.

[0091] Conduct a compressive strength test on the non-firing brick obtained in this example, and the measured compressive strength at 8 h is 12.6 MPa, and the compressive strength at 24 h is 22.3 MPa.

[0092] Comparative Example 1

[0093] A non-firing brick, and its preparation method is as follows:

[0094] Take 7 kg of shield construction waste soil, dry it, and crush it to less than 2 mm for standby;

[0095] Take 3 kg of portland cement and mix it evenly into the above-mentioned construction waste soil;

[0096] Add 2 kg of water to the above-mentioned mixed materials and stir evenly;

[0097] Pour the mixed material into a brick mold pre-coated with a mold release agent and press it with a two-way press for 60 seconds, applying in three stages: 0 → 10 MPa (10 s) → 15 MPa (20 s) → 20 MPa (30 s) to obtain a brick blank;

[0098] Place the brick blank in the open air for natural curing, without other covering on the upper part, and let it stand for 8 h;

[0099] Conduct a compressive strength test on the brick body, and the measured compressive strength after 8 h is 4.1 MPa,

[0100] After standing for 24 h, the measured compressive strength after 24 h is 6.3 MPa.

[0101] Heat at 200 °C for 24 h, and the measured compressive strength is 10.7 Mpa.

[0102] Comparative Example 2

[0103] Compared with Example 1, the difference in Comparative Example 2 is that the curing agent used in Comparative Example 2 does not contain nano-silica. Conduct a compressive strength test on the non-fired brick prepared in this example, and the measured compressive strength after 8 h is 7.6 MPa, and the compressive strength after 24 h is 16.3 MPa.

[0104] Comparative Example 3

[0105] Compared with Example 1, the difference in Comparative Example 3 is that the curing agent used in Comparative Example 3 does not contain lithium carbonate. Conduct a compressive strength test on the non-fired brick prepared in this example, and the measured compressive strength after 8 h is 6.5 MPa, and the compressive strength after 24 h is 15.8 MPa.

[0106] The compressive strength tests of the non-fired bricks prepared in the above examples and comparative examples were carried out by the method in GB / T 50129-2011 "Standard for Test Methods of Basic Mechanical Properties of Masonry".

[0107] The compressive strengths of the non-fired bricks prepared in Example 1 and Comparative Example 1 were measured respectively after natural curing for 8 h and 24 h, and the comparison is as follows Figure 2As shown, it can be seen that the strength of the ultra-early-strength soil-based non-fired bricks prepared with the curing agent of the present invention can reach 10 Mpa after 8 hours of natural curing, meeting the strength grade requirement of MU10. After 24 hours of natural curing, the strength of the brick body is greatly improved, reaching 20 Mpa, meeting the strength grade requirement of MU20. However, the strength of the non-fired bricks prepared with the same amount of cement is less than 5 Mpa after 8 hours of natural curing, and the strength after 24 hours of natural curing is still far less than 10 Mpa, not meeting the strength required for brick body use. Thus, it can be known that the soil-based non-fired bricks of the present invention can meet the strength requirements in a very short time under natural curing, featuring ultra-early-strength bricks.

[0108] The compressive strengths of the non-fired bricks prepared in Example 1 and Comparative Example 2 were measured respectively after 8 hours and 24 hours of natural curing, and the comparison is as Figure 2 shown. It can be seen that without adding nano-silica in the non-fired brick curing agent, the improvement of the compressive strength of the prepared non-fired bricks is not obvious, especially the enhancement rate of the compressive strength of the brick body in the short term is relatively small. It is speculated that the lack of nano-silica component may cause the tiny pores in the brick body not to be effectively filled. However, the combined use of components with different particle sizes of nano-silica, mineral powder, and fly ash in Example 1 significantly improves the strength of the non-fired bricks.

[0109] The compressive strengths of the non-fired bricks prepared in Example 1 and Comparative Example 3 were measured respectively after 8 hours and 24 hours of natural curing, and the comparison is as Figure 2 shown. It can be seen that without adding lithium carbonate in the non-fired brick curing agent, the improvement of the compressive strength of the prepared non-fired bricks is not obvious. While adding lithium carbonate in the curing agent of the present invention, which acts as a catalyst, synergistically accelerates the hydration reaction of each component in the alkaline environment, promoting the formation of more hydration products. These hydration products are intertwined to form a dense network structure, significantly improving the early strength of the brick body.

[0110] The durability performance test of the non-fired bricks prepared in Example 1 was carried out, specifically the frost resistance test (using the dry-wet cycle and freeze-thaw cycle methods in GB / T 2542-2012 "Test Methods for Masonry Bricks"), and the test results are as Figure 3 shown. It can be seen that after 20 dry-wet cycles, the strength of the brick body is above 19 Mpa, still maintaining a relatively high strength level, indicating that the brick body structure prepared by the present invention is stable and can be used in a humid environment. After 20 freeze-thaw cycles, the change in the strength of the brick body is very small, still above 20 Mpa, indicating that the brick body of the present invention has excellent cold resistance and can be applied to low-temperature environments.

[0111] A comparative analysis was carried out on the cost of the curing agent of the present invention and the cost of using PO42.5 cement as the curing agent in the prior art, as Figure 4 shown. It costs 79.8 yuan of the curing agent of the present invention to process 1 ton of soil to prepare non-fired bricks, while it requires 105 yuan of PO42.5 cement. As Figure 5As shown, correspondingly, to prepare one non-fired brick of standard size, it requires 0.13 yuan of the curing agent of the present invention, while it requires 0.18 yuan of PO42.5 cement. It can be seen that when the present invention processes the same amount of construction waste to prepare non-fired construction waste bricks, compared with the prior art, the cost is greatly reduced, the economy is better, and it is suitable for popularization.

[0112] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as a limitation on the essence and scope of the present invention. Various modifications made by those of ordinary skill in the art to the above embodiments after reading this specification all fall within the scope protected by the present invention.

Claims

1. A non-fired brick curing agent, characterized in that, It includes curing agent A and curing agent B; by mass parts, the curing agent A includes 76 - 80 parts of mineral powder, 8 - 10 parts of quicklime, 2 - 3 parts of fly ash, 4.5 - 4.9 parts of desulfurized gypsum, and 4.5 - 4.9 parts of sulfoaluminate cement; the curing agent B includes 1 - 1.5 parts of nano-silica, 0.1 - 0.3 parts of lithium carbonate, and 0.1 - 0.3 parts of naphthalene series water reducer.

2. The non-fired brick curing agent according to claim 1, characterized in that, The curing agent A includes 76 - 79 parts of mineral powder, 8 - 9 parts of quicklime, 2 - 2.5 parts of fly ash, 4.8 - 4.9 parts of desulfurized gypsum, and 4.8 - 4.9 parts of sulfoaluminate cement; the curing agent B includes 1 - 1.2 parts of nano-silica, 0.1 - 0.2 parts of lithium carbonate, and 0.1 - 0.2 parts of naphthalene series water reducer.

3. The non-fired brick curing agent according to claim 1, characterized in that, The naphthalene series water reducer is at least one of FDN water reducer, UNF water reducer, NF water reducer, and HN water reducer.

4. The non-burning brick curing agent according to claim 1, wherein, The fly ash is high-calcium fly ash.

5. A super-early-strength soil-cement-based non-fired brick, characterized in that, The raw material of the ultra-early-strength muck-based non-fired brick includes muck and the non-fired brick curing agent according to any one of claims 1 - 4.

6. The ultra-early-strength soil-cement-based non-fired brick according to claim 5, characterized in that, By mass percentage, the muck is 70% - 80%, and the non-fired brick curing agent is 20% - 30%.

7. An ultra-early-strength muck-based non-fired brick according to claim 5, characterized in that, The particle size of the muck is less than or equal to 2 mm.

8. An ultra-early-strength muck-based non-fired brick according to claim 5, characterized in that, The muck is at least one of tunnel shield muck, pile foundation engineering muck, earthwork muck, and demolition engineering muck.

9. The preparation method of a super-early-strength soil-cement-based non-fired brick according to any one of claims 5-8, characterized in that, It includes the following steps: Crush the muck to a particle size less than or equal to 2 mm for standby; Prepare the non-fired brick curing agent A: Mix mineral powder, quicklime, fly ash, desulfurized gypsum, and sulfoaluminate cement powder; Add the non-fired brick curing agent A to the crushed muck and mix evenly to obtain powder 1; Prepare the non-fired brick curing agent B: Mix nano-silica, lithium carbonate, and naphthalene series water reducer powder; Add the non-fired brick curing agent B to the powder 1 and mix evenly to obtain powder 2; Add water to the powder 2, and the mass percentage of the water in the powder 2 is 20% - 22%, and stir evenly to obtain a mixed wet material; Make the mixed wet material into brick blanks; Naturally cure for 8 hours to obtain the ultra-early-strength muck-based non-fired brick.

10. The preparation method of an ultra-early-strength brick made of muck base without firing according to claim 9, characterized in that, The brick blanks are formed by a press, pressurize to 10 Mpa and press for 10 s, pressurize to 15 Mpa and press for 20 s, pressurize to 20 Mpa and press for 30 s.

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