High-performance environment-friendly foam polymeric soil and preparation method thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to high-performance environment-friendly foam polymeric soil and a preparation method thereof. The high-performance environment-friendly foam polymerized soil is prepared from the following components in parts by weight: 60 to 70 parts of sulphoaluminate cement, 30 to 50 parts of fly ash, 10 to 20 parts of raw material soil, 6 to 10 parts of foam, 0.5 to 1 part of water reducing agent, 0.5 to 2 parts of glass fiber, 0.1 to 0.5 part of aramid nanofiber and 50 to 60 parts of water. On the basis of the glass fibers, a small amount of soft aramid nanofibers are added to improve the technical problem of low mechanical strength of the foam polymerized soil. The foam polymeric soil has a pressure-bearing effect, the glass fibers can form a reinforced network, the aramid nanofibers are doped as a reinforced material, and the glass fibers and the aramid nanofibers interact with each other and are uniformly distributed in the material, so that the use amount of cement can be greatly reduced, and waste can be utilized on a large scale; and the mechanical property of the foam polymerized soil is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a high-performance environmentally friendly foamed polymer soil and a preparation method thereof. Background Art

[0002] The reconstruction and expansion of expressways are different from the construction of new expressways. The differential settlement caused by the splicing of the new and old roadbeds has always been a difficult point in the reconstruction and expansion project. The main reason for the disease at the splicing site of the new and old roadbeds is the difference in settlement between the new and old foundations. After the old roadbed was put into use, the settlement deformation has basically stabilized under the influence of factors such as vehicle load and road structure deadweight. However, the newly filled roadbed will still have a large settlement deformation, resulting in uneven settlement of the new and old roadbeds, which will cause cracks in the splicing site and cause serious damage to the roadbed and pavement structure. In order to solve this problem, domestic and foreign experts and scholars have proposed many new materials and technologies, including the application of geosynthetics, splicing of roadbed excavation steps, lightweight soil embankments, cement mixing pile foundation treatment, high-pressure rotary spray gun foundation treatment construction, strong tamping and impact rolling, etc. These technologies have played a positive role in the uneven settlement of the new and old roadbeds, but some technologies still have limitations such as increasing project costs, increasing construction difficulty, requiring a large construction space, and requiring high performance of construction machinery.

[0003] Foam lightweight polymer soil has unique advantages in controlling differential settlement in roadbed widening due to its light weight, good uprightness, adjustable strength and density, and small construction restrictions. As a roadbed widening method, foam polymer soil has changed from the traditional concept of improving differential settlement by various means to improve the bearing capacity of soft soil foundation, from strengthening the bearing capacity of the soil foundation to reducing the deadweight, which reduces the deadweight stress on the soil foundation on the one hand, and reduces the additional stress on the existing old roadbed on the other hand. At the same time, foam polymer soil can be directly poured by pumping during construction without vibration and rolling, so it is suitable for large-scale mechanized construction and requires little construction space. At the same time, the outer side of the foam polymer soil roadbed is supported by a cast-in-place concrete vertical retaining structure, and the foam polymer soil is poured inside. There is no need to increase the slope and stabilize the roadbed to prevent slippage like the traditional fill roadbed, so land acquisition can be reduced. Especially with the rapid economic development and the further expansion of urban areas, various types of buildings have been built along the highways originally located in the suburbs, resulting in higher land acquisition costs and greater difficulties in land acquisition. The advantages of using foam polymer soil for roadbed widening are more prominent.

[0004] Commonly used foamed polymer soil components are mainly cement, water and foaming agent, with cement accounting for the largest proportion of raw materials. Cement, as a traditional cementitious material, is widely used in my country's civil engineering industry, but the production of cement is very likely to cause environmental pollution and has high carbon emissions, which is contrary to the current concept of ecological civilization construction. At the same time, the energy consumption of cement production is very high, and the price is high, which increases the application cost. In addition, although the foamed polymer soil prepared with pure cement has high strength, its crack resistance is poor, which affects the durability of the foamed polymer soil roadbed, which is closely related to the properties of the cement material itself. Therefore, how to reduce the amount of cement, use more energy-saving and environmentally friendly materials instead of cement to prepare foamed polymer soil, and further improve the mechanical properties of foamed polymer soil, is of great significance to the large-scale application and promotion of foamed polymer soil roadbed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a high-performance environmentally friendly foam polymer soil, which has the advantages of environmental protection and high mechanical strength.

[0006] The present invention is achieved through the following technical solutions: A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 60-70 parts of sulphoaluminate cement, 30-50 parts of fly ash, 10-20 parts of raw soil, 6-10 parts of foam, 0.5-1 part of water reducer, 0.5-2 parts of glass fiber, 0.1-0.5 parts of aramid nanofiber, and 50-60 parts of water.

[0007] At present, the main component of foamed polymer soil is cement, and the huge energy consumption and carbon emissions in the cement production process are contrary to the energy-saving and environmental protection concept pursued by most countries at present. Therefore, the raw materials for preparing foamed polymer soil have been expanded from traditional cement to a part of highly active industrial solid waste, such as blast furnace slag, steel slag, fly ash, etc. Among them, fly ash is a solid waste generated during coal combustion, and its main components include inorganic substances such as silicon dioxide, aluminum oxide, iron oxide, calcium oxide, and magnesium oxide. It can be used as a concrete admixture to replace part of the cement and improve the working performance and durability of the concrete. It is worth noting that the large amount of fly ash added will significantly reduce the strength of the material, which is mainly because the fly ash activity is released too slowly, resulting in the slow setting phenomenon of the material, the setting time is prolonged, and then the strength reaches the standard. The amount of excavated waste soil and industrial waste soil in my country's engineering construction every year cannot be estimated, and the secondary use of waste soil will produce huge social and economic benefits. The present invention adds a certain amount of raw soil, which not only solves the problem of environmental pollution, but also reduces the amount of cement and saves costs.

[0008] Sulphoaluminate cement has the characteristics of high early strength and high strength, and can reach high strength in a short time; compared with silicate cement, sulphoaluminate cement has excellent impermeability and high frost resistance, and is suitable for projects in cold and humid environments.

[0009] However, components such as fly ash and raw soil have lower activity than cement, and adding a small amount can improve the mechanical properties of cement materials; but adding a large amount will reduce the activity of cement, on the one hand reducing the bonding performance between hydration products and aggregates, and at the same time will disperse in the slurry, causing defects in the structure after hardening, thus affecting the structural strength.

[0010] In order to solve the technical problem that the excessive amount of fly ash and raw soil leads to the decrease of mechanical properties, the present invention adds glass fiber and aramid nanofiber. As a traditional reinforcing filler, the addition of glass fiber greatly improves the mechanical properties of foamed polymer soil. However, glass fiber is too hard and difficult to be fixed in the pore wall between the pores of foamed concrete, and cannot meet the technical requirements of rigidity and toughness balance of foamed polymer soil. In terms of toughening, aramid nanofiber is better than glass fiber. Therefore, on the basis of glass fiber, the present invention chooses to add a small amount of softer aramid nanofiber to improve the mechanical properties of foamed polymer soil. In the foamed polymer soil structure based on fiber composite modification, the foamed polymer soil plays a pressure-bearing role, while the fiber plays a role of bearing the tensile stress generated by deformation and cracking under load, and the compressive strength is improved due to the reinforcement effect of the fiber. After the damage, the structural fragments still maintain good integrity under the constraint of the fiber, while the unreinforced foamed polymer soil specimens directly collapse and split into fragments. The addition of aramid nanofiber improves the compressive and flexural strengths. Among them, glass fiber can form a reinforcement network, while aramid nanofibers are added as reinforcement materials. The glass fiber and aramid nanofibers interact with each other, making the two evenly distributed inside the material. Cracks will be limited by the mesh structure formed by glass fiber and aramid nanofibers.

[0011] Furthermore, the fly ash is at least one of primary fly ash and secondary fly ash. Furthermore, the amount of fly ash is 35-40 parts.

[0012] Furthermore, the raw soil is at least one of silty clay, silty soil, expansive soil, red mud or white mud; and the particle size of the raw soil is 0.5-3 mm.

[0013] Furthermore, the density of the foam is 40-60 kg / m 3 The foam used in the present invention is prepared by diluting the polymer composite cement foaming agent of Weihai Zhongsheng Company with water to form a foam liquid, and then introducing compressed air to obtain a foam liquid with a density of 50kg / m 3 The standard bubble column of foam has a water secretion of 22 ml and a sedimentation distance of 1 mm after standing for 1 hour.

[0014] Furthermore, the water reducer is at least one of a polycarboxylic acid water reducer, a melamine water reducer, and a naphthalene water reducer.

[0015] Furthermore, the length of the glass fiber is 3-25 mm. The diameter of the glass fiber is not particularly limited, and the common diameter is 3-30 μm.

[0016] Furthermore, the length of the glass fiber is 6-12 mm. Appropriate fiber length is more conducive to the dispersion of the glass fiber in the foamed polymer soil, and is easy to form a reinforcement network, and is convenient to form a network-reinforcement rib structure with the aramid nanofiber.

[0017] Furthermore, the aramid nanofiber has a length of 50-200 μm and a diameter of 50-200 nm.

[0018] Furthermore, 60-70 parts of sulphoaluminate cement, 30-50 parts of fly ash, 10-20 parts of raw soil, 6-10 parts of foam, 0.5-1 part of water reducer, 1-1.5 parts of glass fiber, 0.1-0.5 parts of aramid nanofiber, and 50-60 parts of water. As the main body of the reinforcing network, the amount of glass fiber is not the more the better. The addition of an appropriate amount of glass fiber can effectively improve the flexural strength of the foamed polymer soil and increase the toughness of the foamed polymer soil.

[0019] On the other hand, the present invention also provides a method for preparing the high-performance environmentally friendly foamed polymer soil, comprising the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0020] Beneficial effects: The present invention provides a method for preparing foamed polymer soil using fly ash and raw soil as raw materials, which can be used to solve the problem of fly ash and raw soil accumulation, and has great economic value and potential for promotion and application. In addition, the present invention adds glass fiber and aramid nanofiber. On the basis of glass fiber, a small amount of softer aramid nanofiber is selected to improve the shrinkage and low elastic modulus problems of foamed polymer soil. Glass fiber can form a reinforced network, and aramid nanofiber is added as a reinforcing material. Glass fiber and aramid nanofiber interact with each other so that the two are evenly distributed inside the material. Cracks will be limited by the mesh structure formed by glass fiber and aramid nanofiber. The present invention meets the design index requirements for highway reconstruction, expansion and widening of roadbed. Its application can not only achieve a significant reduction in cement consumption and large-scale utilization of waste, but also improve the mechanical properties of foamed polymer soil. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 60 parts of sulphoaluminate cement, 30 parts of fly ash, 10 parts of raw soil, 6 parts of foam, 0.5 parts of water reducer, 1 part of glass fiber, 0.1 parts of aramid nanofiber, and 50 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylic acid water reducer; the glass fiber is 6 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0023] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0024] Example 2 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 70 parts of sulphoaluminate cement, 40 parts of fly ash, 20 parts of raw soil, 10 parts of foam, 1 part of water reducer, 1.5 parts of glass fiber, 0.5 parts of aramid nanofiber, and 60 parts of water; the fly ash is secondary fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 12 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0025] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0026] Example 3 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 60 parts of sulphoaluminate cement, 40 parts of fly ash, 10 parts of raw soil, 10 parts of foam, 0.5 parts of water reducer, 1.5 parts of glass fiber, 0.1 parts of aramid nanofiber, and 60 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylic acid water reducer; the glass fiber is 6 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0027] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0028] Example 4 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 62 parts of sulphoaluminate cement, 33 parts of fly ash, 14 parts of raw soil, 7 parts of foam, 0.6 parts of water reducer, 1.1 parts of glass fiber, 0.2 parts of aramid nanofiber, and 53 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0029] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0030] Example 5 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 68 parts of sulphoaluminate cement, 37 parts of fly ash, 17 parts of raw soil, 8 parts of foam, 0.8 parts of water reducer, 1.4 parts of glass fiber, 0.4 parts of aramid nanofiber, and 57 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 12 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0031] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0032] Example 6 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 50 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.2 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0033] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0034] Example 7 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 0.5 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0035] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0036] Example 8 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 2 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0037] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0038] Example 9 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.2 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylic acid water reducer; the glass fiber is 3 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0039] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0040] Example 10 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.2 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylic acid water reducer; the glass fiber is 25 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0041] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0042] Embodiment 11 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.2 parts of glass fiber, 0.3 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0043] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0044] Comparative Example 1 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 0 parts of glass fiber, 1.5 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0045] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0046] Comparative Example 2 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.5 parts of glass fiber, 0 parts of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0047] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0048] Comparative Example 3 A high-performance environmentally friendly foam polymer soil, comprising the following components in parts by weight: 66 parts of sulphoaluminate cement, 35 parts of fly ash, 15 parts of raw soil, 8 parts of foam, 0.7 parts of water reducer, 1.2 parts of glass fiber, 1 part of aramid nanofiber, and 56 parts of water; the fly ash is first-grade fly ash; the raw soil is silty clay with a particle size of 1 mm; the density of the foam is 50 kg / m 3 ; The water reducer is a polycarboxylate water reducer; the glass fiber is 9 mm long; the aramid nanofiber is 60 μm long and has a diameter of 60 nm.

[0049] A method for preparing high-performance environmentally friendly foamed polymer soil comprises the following steps: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

[0050] Performance test: The compressive strength and flexural strength of the foamed polymer soil prepared in Examples 1-11 and Comparative Examples 1-3 were tested according to CJJ / T177-2012 and GB / T 11969-2020, respectively. The results are shown in Table 1.

[0051] As can be seen from Table 1, the present invention adds glass fiber and aramid nanofiber to solve the technical problem that the excessive amount of fly ash and raw soil leads to a decrease in mechanical properties. The addition of glass fiber greatly improves the mechanical properties of foamed polymer soil. In terms of toughening, aramid nanofiber is better than glass fiber. Therefore, on the basis of glass fiber, the present invention chooses to add a small amount of softer aramid nanofiber to improve the mechanical properties of foamed polymer soil. In the foamed polymer soil structure based on fiber composite modification, the foamed polymer soil plays a pressure-bearing role, while the fiber plays a role in bearing the tensile stress generated by deformation and cracking under load, and due to the reinforcement effect of the fiber, not only the compressive strength is improved, but also the foamed polymer soil specimen still has good integrity after destruction. After the damage, the structural fragments still maintain good integrity under the constraint of the fiber, while the unreinforced foamed polymer soil specimen is easy to collapse and split into fragments. Compared with Example 11, Comparative Example 1-2 lacks aramid nanofiber or glass fiber, and its mechanical properties are greatly reduced. It shows that the incorporation of aramid nanofiber improves the compressive and flexural strength. Among them, glass fiber can form a reinforced network, and aramid nanofiber is added as a reinforcing material. The glass fiber and aramid nanofiber interact with each other, so that the two are evenly distributed inside the material, and the two work together to improve the mechanical properties of the foam polymer soil. It can be seen from Comparative Example 3 that the more aramid nanofiber is added, the better. This is because aramid nanofiber is used as a reinforcing rib of the glass fiber network. When the amount is too much, the nanofiber is easy to clump, and the fibers that play a bridging role are reduced, which affects the matrix's grip on the fibers, thereby affecting the flexural and compressive properties of the specimen.

[0052] In summary, the specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments under the concept of the present invention, but are not intended to limit the present invention; those skilled in the art can make adaptive adjustments within the concept and protection scope of the present invention.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance environmentally friendly foamed polymer soil, characterized in that: Contains the following components in parts by weight: 60-70 parts of sulphoaluminate cement, 30-50 parts of fly ash, 10-20 parts of raw soil, 6-10 parts of foam, 0.5-1 part of water reducer, 0.5-2 parts of glass fiber, 0.1-0.5 parts of aramid nanofiber, and 50-60 parts of water.

2. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The fly ash is at least one of primary fly ash and secondary fly ash.

3. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The raw soil is at least one of silty clay, silty soil, expansive soil, red mud or white mud; and the particle size of the raw soil is 0.5-3 mm.

4. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The density of the foam is 40-60 kg / m 3 .

5. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The water reducer is at least one of a polycarboxylic acid water reducer, a melamine water reducer and a naphthalene water reducer.

6. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The length of the glass fiber is 3-25 mm.

7. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The glass fiber has a length of 6-12 mm.

8. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: The aramid nanofiber has a length of 50-200 μm and a diameter of 50-200 nm.

9. The high-performance environmentally friendly foamed polymer soil according to claim 1, characterized in that: 60-70 parts of sulphoaluminate cement, 30-50 parts of fly ash, 10-20 parts of raw soil, 6-10 parts of foam, 0.5-1 part of water reducer, 1-1.5 parts of glass fiber, 0.1-0.5 parts of aramid nanofiber, and 50-60 parts of water.

10. A method for preparing high-performance environmentally friendly foamed polymer soil according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Sulphoaluminate cement, fly ash, raw soil, glass fiber, aramid nanofiber and water are mixed and stirred evenly to obtain a premix; (2) Add foam and water reducer to the premix and mix well; (3) Casting and curing to obtain high-performance environmentally friendly foam polymer soil.

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