A lightweight building material containing vinasse and a preparation method and application thereof

Abstract

The present application relates to a kind of light building materials containing vinasse and its preparation method and application, belong to light building material technical field, material includes cement, composite activated powder, modified reinforcing fiber, composite foaming agent, graded expanded perlite, shale haydite, weather-resistant reinforcing additive, waterproof plugging additive, heat preservation stabilizing additive, polymer of methyl oxirane and oxirane dimethyl ether etc. Component.Composite activated powder is the mixture of vinasse, slag powder, expandable graphite powder and nanometer silicon dioxide, is prepared after surface modification by silane coupling agent KH-560.Modified reinforcing fiber is short fiber made of glass fiber reinforced PP particle melt extrusion, is prepared after surface modification by silane coupling agent KH-550.Composite foaming agent is prepared by mixing vinasse protein solution, ammonium bicarbonate, wood fiber and tween-80.Each component is used in cooperation, interface modification is optimized, realizes the light weight of material, and improves strength, waterproof, anti-permeability and frost resistance.

Description

A lightweight building material containing distiller's grains, its preparation method and application Technical Field

[0001] This invention belongs to the field of lightweight building materials technology, specifically relating to a lightweight building material containing distiller's grains, its preparation method, and its application. Background Technology

[0002] Traditional building materials such as bricks, stones, and concrete, while possessing advantages such as high strength and durability, suffer from significant drawbacks including high density and weight. This not only leads to increased building energy consumption but also increases construction difficulty and transportation costs. Against this backdrop, lightweight building materials, with their combined advantages of low density, high strength, and thermal insulation, are gradually replacing traditional materials. Lightweight building materials typically have a lower density than traditional materials, significantly reducing building weight, minimizing structural material consumption, simplifying construction processes, and improving efficiency. Lightweight materials can meet structural safety requirements while achieving energy conservation and emission reduction goals.

[0003] The research and development of lightweight building materials can be traced back to the early 20th century. Early materials primarily consisted of porous materials such as aerated concrete and lightweight bricks, which reduced density by introducing pores. However, these materials suffered from insufficient strength and poor waterproofing. With advancements in materials science and manufacturing technology, lightweight building materials have gradually evolved towards higher strength, greater multifunctionality, and greater composite properties. Modern lightweight materials achieve a balance between density and strength through optimized formulation design, such as adding lightweight aggregates like expanded clay and perlite, and improved manufacturing processes, such as foaming molding and fiber reinforcement technology. For example, lightweight concrete, by incorporating polystyrene particles and glass fibers, reduces density while increasing compressive strength, and also possesses good thermal insulation properties. Fiber-reinforced cement boards, for instance, reduce density and increase flexural strength by combining carbon fiber, glass fiber, and cement-based materials, and also possess multifunctional properties such as fire resistance and sound insulation.

[0004] In terms of market demand, the rapid development of prefabricated buildings has driven the growth in demand for products such as lightweight partition walls and prefabricated lightweight components. Currently, lightweight building materials are widely used in building components such as walls, roofs, and floors, covering multiple fields including residential, commercial, and industrial buildings, and the market size continues to expand.

[0005] However, existing lightweight building materials still face some technical bottlenecks: most materials still suffer from problems such as low strength, high water absorption, poor impermeability, and poor frost resistance. Therefore, it is necessary to further optimize material formulations and improve preparation processes to enhance the performance and durability of lightweight building materials. Summary of the Invention

[0006] To address the problems of low strength, high water absorption, poor impermeability, and poor frost resistance in existing lightweight building materials, this invention provides a lightweight building material containing distiller's grains, its preparation method, and its application. Through precise selection of components such as cement, activating powder, reinforcing fibers, foaming agent, polymer foam stabilizer, lightweight aggregate, and functional additives, interface modification optimization, and process parameter matching, the core contradiction of insufficient strength and lightweight, and inadequate waterproofing and frost resistance in traditional lightweight building materials is effectively resolved, achieving a synergistic unity of lightweighting and high performance. The specific technical solution is as follows:

[0007] A lightweight building material containing distiller's grains comprises the following raw materials in parts by weight: 24-29 parts ordinary silicate cement, 18-23 parts composite activated powder, 2.5-3.5 parts modified reinforcing fiber, 3.5-5.0 parts composite foaming agent, 14-18 parts graded expanded perlite, 9-13 parts shale ceramsite, 3-5 parts weather-resistant reinforcing agent, 2-3 parts waterproof sealing agent, 2-3 parts thermal insulation stabilizing agent, 0.6-1.0 parts sodium sulfate, 0.8-1.2 parts polycarboxylate superplasticizer, 0.1-0.15 parts polymer of methyl ethylene oxide and ethylene oxide dimethyl ether, and 23-28 parts water;

[0008] The composite activated powder is a mixture of distiller's grains, slag powder, expandable graphite powder, and nano-silica in a mass ratio of (4-6):(3-4):(0.1-0.3):(0.1-0.3), which is then surface-modified with silane coupling agent KH-560. The modified reinforcing fiber is a short fiber made by melt extrusion of glass fiber reinforced PP particles, which is then surface-modified with silane coupling agent KH-550. The composite foaming agent is a mixture of distiller's grains protein solution, ammonium bicarbonate, lignocellulose, and Tween-80 in a mass ratio of (3-5):(1-1.5):(0.3-0.5):(0.1-0.2).

[0009] The preparation method of the composite activated powder in the above materials includes: mixing distiller's grains, slag powder, expandable graphite powder and nano-silica in a mass ratio of (4-6):(3-4):(0.1-0.3):(0.1-0.3) to obtain a mixture; preparing a 1.5wt%-2wt% silane coupling agent KH-560 solution with an ethanol aqueous solution to obtain a modifier; adding the mixture to the modifier in a solid-liquid mass ratio of 1:(2-3), stirring, drying, and pulverizing through a 100-150 mesh sieve to obtain the composite activated powder.

[0010] The preparation method of the modified reinforcing fiber in the above materials includes: melt extruding glass fiber reinforced PP, granulating it to make short fibers with a diameter of 0.3 mm to 0.5 mm and a length of 5 mm to 8 mm; preparing a 1.5 wt% to 2.5 wt% silane coupling agent KH-550 solution with an ethanol aqueous solution, adjusting the pH to 4 to 5, stirring and pre-hydrolyzing to obtain a modified solution; immersing the short fibers in the modified solution at a material-to-liquid mass ratio of 1:(6 to 8), stirring, filtering, and drying the filter cake to obtain the modified reinforcing fiber.

[0011] The preparation method of the composite foaming agent in the above materials includes: mixing the ingredients according to the mass ratio of distillers' grains protein liquid: ammonium bicarbonate: lignocellulose: Tween-80 = (3~5): (1~1.5): (0.3~0.5): (0.1~0.2), stirring at 50℃~60℃ and 300rpm~350rpm for 1h~1.5h to obtain the composite foaming agent.

[0012] The graded expanded perlite in the above materials includes coarse expanded perlite with a particle size of 20-40 mesh and fine expanded perlite with a particle size of 60-80 mesh, in a mass ratio of (2-3):(1-1.5).

[0013] In the above materials, the particle size range of the shale ceramsite is 3mm to 8mm.

[0014] In the above materials, the weather-resistant enhancing agent includes silica fume, a composite antifreeze agent, and UV-328 in a mass ratio of (2-3):(0.8-1.2):(0.1-0.2); the composite antifreeze agent includes sodium nitrite and urea in a mass ratio of (1-2):(1-1.5).

[0015] The waterproofing and sealing agent in the above materials includes a deep-penetrating crystallizing sealing waterproofing agent, cetyl phosphate-cetyl phosphate diethanolamine and an expanding fiber anti-crack waterproofing agent in a mass ratio of (1.5-2.0):(0.5-0.8):(0.3-0.5).

[0016] In the above materials, the thermal insulation and stabilizing agent includes montmorillonite and fluorocarbon surfactant in a mass ratio of (0.8-1.5):(0.1-0.2).

[0017] The preparation method of the above-mentioned lightweight building material containing distiller's grains includes the following steps:

[0018] S1: According to the mass fraction of raw materials, ordinary silicate cement, composite activated powder, graded expanded perlite, shale ceramsite, modified reinforcing fiber and sodium sulfate are mixed. Then, weather-resistant reinforcing agent, waterproof sealing agent, thermal insulation stabilizing agent and polycarboxylate superplasticizer are added and mixed. Then, a mixture of premixed methyl ethylene oxide and ethylene oxide dimethyl ether polymer and water is added and mixed. Finally, a composite foaming agent is added and mixed to form a foam slurry with an air content of 50 vol% to 60 vol%, thus obtaining a lightweight building material.

[0019] S2: Inject lightweight building materials into precast component molds or on-site casting molds, vibrate to compact the material, cover the surface with plastic film, and cure naturally for 10-12 hours. Demold, water spray for 7 days, and then cure naturally for 28 days.

[0020] The aforementioned lightweight building materials are used in the preparation of non-load-bearing walls, prefabricated insulation components, underfloor heating backfill layers, or sound insulation and noise reduction components in building engineering.

[0021] This invention provides a lightweight building material containing distiller's grains, its preparation method, and its application. The beneficial effects include:

[0022] I. This invention's lightweight building material, through precise component selection, interface modification optimization, and process parameter matching, effectively solves the core contradictions of traditional lightweight building materials, namely, the insufficient balance between strength and lightweight, and the inadequacy of waterproofing and frost resistance, achieving a synergistic unity of lightweight and high performance. Its core principle is to construct a dense gel matrix and a protective system with a uniform microporous structure through the full reaction of active components, the strengthening of interfacial adhesion, and the precise control of pore structure, ensuring a material strength of 800 kg / m³. 3 ~850kg / m 3 Its low-density characteristics compensate for the structural defects of traditional lightweight materials and meet the comprehensive performance requirements of building engineering for non-load-bearing components.

[0023] II. The composite activated powder is made from a reasonable ratio of distiller's grains, slag powder, expandable graphite powder, and nano-silica, and modified with KH-560. The active components of distiller's grains and slag powder form dense hydrates that fill the pores of the matrix; nano-silica and expandable graphite powder optimize the microstructure; KH-560 modification improves the interfacial compatibility between the powder and the cementitious base through chemical bonding, reduces agglomeration defects, and strengthens the density and mechanical properties of the matrix.

[0024] Third, the high strength of glass fiber reinforced PP provides mechanical support for the material, and the short fiber morphology facilitates uniform dispersion; KH-550 modification forms chemical bonds between the fiber and the matrix, improving the anchoring effect and load transfer efficiency, effectively inhibiting crack initiation and propagation, and enhancing the material's flexural strength, compressive strength and structural stability.

[0025] IV. The composite foaming agent is prepared by mixing distillers' grains protein solution, ammonium bicarbonate, wood fiber, and Tween-80 in a specific ratio. The distillers' grains protein solution promotes foaming and forms a stable liquid film, preventing bubble rupture; ammonium bicarbonate decomposes to produce uniform gas; wood fiber and Tween-80 assist in foam stabilization, synergistically forming the composite foaming agent. In the later stage, it works with a polymer (a polymer of methyl ethylene oxide and ethylene oxide dimethyl ether) to stabilize the foam, effectively forming a fine, uniform, and closed microporous structure, which reduces the material density and avoids the degradation of waterproof and mechanical properties caused by interconnected pores.

[0026] Fifth, the combination of graded expanded perlite and shale ceramsite is reasonable. The coarse and fine graded expanded perlite optimizes the skeleton pore structure, while the shale ceramsite provides lightweight support. The two work together to achieve a dense skeleton and uniform micropores, taking into account both lightweight and mechanical load-bearing capacity.

[0027] VI. Weather-enhancing additives include silica fume, composite antifreeze, and UV-328. The silica fume provides a dense matrix, the antifreeze inhibits frost heave, and UV-328 resists ultraviolet aging, thereby improving weather resistance and stability.

[0028] VII. Based on the comprehensive characteristics of each component of the material, a waterproof sealing agent is designed, including a specific ratio of deep-penetrating crystallizing sealing waterproof agent, cetyl phosphate-cetyl phosphate diethanolamine and expanding fiber anti-crack waterproof agent. These work together to achieve internal crystallization to seal pores, surface hydrophobicity to block moisture, and crack resistance to inhibit penetration channels, thus comprehensively improving waterproof performance. Compared with single components and unreasonable ratios, it has a good synergistic effect.

[0029] 8. Thermal insulation stabilizing agents include montmorillonite and fluorocarbon surfactants, which optimize the thermal insulation structure, inhibit heat transfer, and improve system stability.

[0030] 9. Sodium sulfate accelerates the hydration reaction and promotes gel formation; polycarboxylate superplasticizer improves slurry fluidity, reduces water consumption, and lowers porosity; the polymer of methyl ethylene oxide and ethylene oxide dimethyl ether has both dispersing and foam-stabilizing functions, and precise control of the addition time can reduce the damage to the foaming agent performance and optimize particle dispersion and foam stability.

[0031] 10. In the preparation steps: first mix the inorganic powder and aggregate, then add the additives, and finally add the composite foaming agent to avoid mutual interference between components; the stirring speed and time are designed to ensure uniform dispersion of components while avoiding high-speed stirring from damaging the foam structure.

[0032] In summary, the composite activated powder of this invention forms a multi-element active system with distiller's grains, slag powder, and cement-based materials. The organic active components of the distiller's grains and the inorganic active components of the slag powder synergistically hydrate to generate more dense gel hydrates. Simultaneously, nano-silica and expandable graphite powder fill the micropores, achieving a dual improvement in reaction enhancement and structural densification. The micropores generated by the composite foaming agent, together with the skeleton structure of perlite and ceramsite graded lightweight aggregates, form a macroscopic and microscopic synergistic pore system. This ensures low density while preventing the degradation of waterproof and mechanical properties caused by pore connectivity through the combination of closed micropores and a dense skeleton. The KH-560 modification of the composite activated powder and the KH-550 modification of the modified reinforcing fibers strengthen the interface between the powder, fiber, and matrix, reducing interface defects, improving stress transfer efficiency, and simultaneously enhancing the material's mechanical properties and structural stability. Waterproofing, weathering, and thermal insulation additives form a comprehensive protection system. Waterproofing additives block water penetration channels, weathering additives resist external erosion such as freeze-thaw cycles and ultraviolet rays, and thermal insulation additives maintain temperature stability, enabling the material to maintain long-term performance stability in complex building environments and achieving balanced optimization of mechanical properties, waterproofing performance, weathering performance, and thermal insulation performance. Detailed Implementation

[0033] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these embodiments.

[0034] Example 1

[0035] A lightweight building material containing distiller's grains comprises the following raw materials in parts by weight: 26 parts ordinary silicate cement, 20 parts composite activated powder, 3 parts modified reinforcing fiber, 4.2 parts composite foaming agent, 16 parts graded expanded perlite, 11 parts shale ceramsite, 4 parts weather-resistant reinforcing agent, 2.5 parts waterproof sealing agent, 2.5 parts thermal insulation stabilizing agent, 0.8 parts sodium sulfate, 1 part polycarboxylate superplasticizer, 0.12 parts polymer of methyl ethylene oxide and ethylene oxide dimethyl ether, and 25 parts water.

[0036] The preparation method of the composite activated powder includes: drying wheat lees to a moisture content of 3wt%, pulverizing to a D50 of 32μm, and passing through a 100-mesh sieve. Pulverizing slag and passing it through a 150-mesh sieve. Mixing the lees, slag powder, expandable graphite powder, and nano-silica at a mass ratio of 5:3.5:0.2:0.2 to obtain a mixture. Preparing a 1.8wt% silane coupling agent KH-560 solution with a 22vol% ethanol aqueous solution to obtain a modifier. Adding the mixture to the modifier at a solid-liquid mass ratio of 1:2.5, stirring at 55℃ for 0.5h, drying at 130℃ to a moisture content of 2.5wt%, pulverizing and passing through a 150-mesh sieve to obtain the composite activated powder.

[0037] The preparation method of the modified reinforced fiber includes: melt extruding glass fiber reinforced PP through an extruder, granulating it, and producing short fibers with a diameter of 0.4 mm and a length of 6 mm. A 2 wt% silane coupling agent KH-550 solution is prepared using a 22 vol% ethanol aqueous solution, and the pH is adjusted to 4.5 with a 6 wt% acetic acid aqueous solution. The solution is then stirred and pre-hydrolyzed at 25°C for 25 min to obtain a modified solution. The short fibers are immersed in the modified solution at a material-to-solution mass ratio of 1:7, stirred at 25°C for 1.5 h, filtered through a 200-mesh sieve, and the filter cake is dried in an air-drying environment at 85°C for 5 h to obtain the modified reinforced fiber.

[0038] The preparation method of the composite foaming agent includes: taking the waste liquid of wheat raw materials (distillers' grains), filtering to remove impurities, and adjusting the protein content to 18wt%. The mixture is prepared according to the mass ratio of distillers' grains:ammonium bicarbonate:lignocellulose:Tween-80 = 4:1.2:0.4:0.15, and stirred at 55℃ and 320rpm for 1 hour to obtain the composite foaming agent.

[0039] The graded expanded perlite includes coarse expanded perlite with a particle size of 20-40 mesh and fine expanded perlite with a particle size of 60-80 mesh, in a mass ratio of 2.5:1.2. The shale ceramsite has a particle size range of 3mm-8mm. Weather-resistant reinforcing agents include silica fume, a composite antifreeze agent, and UV-328 in a mass ratio of 2.5:1:0.15; the composite antifreeze agent includes sodium nitrite and urea in a mass ratio of 1.5:1.2. Waterproofing and sealing agents include a deep-penetrating crystallizing sealing waterproofing agent, cetyl phosphate-cetyl phosphate diethanolamine, and expanded fiber crack-resistant waterproofing agent in a mass ratio of 1.8:0.7:0.4. Thermal insulation and stabilizing agents include montmorillonite and fluorocarbon surfactants in a mass ratio of 1.2:0.15.

[0040] The preparation method of the above-mentioned lightweight building material containing distiller's grains includes the following steps:

[0041] S1: According to the mass fraction of raw materials, ordinary silicate cement, composite activated powder, graded expanded perlite, shale ceramsite, modified reinforcing fiber and sodium sulfate are mixed at 70 rpm for 2.5 min. Then, weather-resistant reinforcing agent, waterproof sealing agent, thermal insulation stabilizing agent and polycarboxylate superplasticizer are added, and the mixture is continued to be mixed at 70 rpm for 2.5 min. Then, a mixture of premixed methyl ethylene oxide and ethylene oxide dimethyl ether polymer and water is added, and the mixture is continued to be mixed at 70 rpm for 1.5 min. Finally, a composite foaming agent is added, and the mixture is mixed at 90 rpm for 3 min to form a foam slurry, thus obtaining a lightweight building material.

[0042] S2: Inject lightweight building materials into precast component molds or on-site casting molds, vibrate at a frequency of 45Hz to compact the material for 25 seconds, cover the surface with a plastic film, allow to cure naturally for 11 hours, demold, and spray with water (4.5L / m² every 8 hours). 2Leave it in the oven for 7 days, then allow it to rest naturally for 28 days.

[0043] In this embodiment, the test sample was cast using a precast component mold that meets the test specifications.

[0044] Example 2

[0045] A lightweight building material containing distiller's grains comprises the following raw materials in parts by weight: 24 parts ordinary silicate cement, 23 parts composite activated powder, 2.5 parts modified reinforcing fiber, 5.0 parts composite foaming agent, 14 parts graded expanded perlite, 13 parts shale ceramsite, 3 parts weather-resistant reinforcing agent, 3 parts waterproof sealing agent, 2 parts thermal insulation stabilizing agent, 1.0 part sodium sulfate, 0.8 parts polycarboxylate superplasticizer, 0.15 parts polymer of methyl ethylene oxide and ethylene oxide dimethyl ether, and 23 parts water.

[0046] The preparation method of the composite activated powder includes: drying barley lees to a moisture content of 4 wt%, pulverizing to a D50 of 10 μm, and passing through a 150-mesh sieve. Pulverizing slag and passing it through a 100-mesh sieve. Mixing the lees, slag powder, expandable graphite powder, and nano-silica at a mass ratio of 6:3:0.3:0.1 to obtain a mixture. Preparing a 1.5 wt% silane coupling agent KH-560 solution with a 25 vol% ethanol aqueous solution to obtain a modifier. Adding the mixture to the modifier at a solid-liquid mass ratio of 1:2, stirring at 50℃ for 1 h, drying at 120℃ to a moisture content of 2.8 wt%, pulverizing and passing through a 150-mesh sieve to obtain the composite activated powder.

[0047] The preparation method of the modified reinforced fiber includes: melt extruding glass fiber reinforced PP through an extruder, granulating it, and producing short fibers with a diameter of 0.3 mm and a length of 8 mm. A 2.5 wt% silane coupling agent KH-550 solution is prepared using a 20 vol% ethanol aqueous solution, and the pH is adjusted to 5 with a 5 wt% acetic acid aqueous solution. The solution is then stirred and pre-hydrolyzed at 20°C for 30 min to obtain a modified solution. The short fibers are immersed in the modified solution at a material-to-solution mass ratio of 1:6, stirred at 30°C for 1.5 h, filtered through a 200-mesh sieve, and the filter cake is dried in an air-drying environment at 80°C for 6 h to obtain the modified reinforced fiber.

[0048] The preparation method of the composite foaming agent includes: taking the waste liquor of barley raw material, filtering to remove impurities, and adjusting the protein content to 15wt%. The liquor is mixed according to the mass ratio of liquor liquor:ammonium bicarbonate:lignocellulose:Tween-80 = 5:1:0.5:0.1, and stirred at 60℃ and 300rpm for 1.5h to obtain the composite foaming agent.

[0049] The graded expanded perlite includes coarse expanded perlite with a particle size of 20-40 mesh and fine expanded perlite with a particle size of 60-80 mesh, in a mass ratio of 2:1.5. The shale ceramsite has a particle size range of 3mm-8mm. Weather-resistant reinforcing agents include silica fume, a composite antifreeze agent, and UV-328 in a mass ratio of 2:1.2:0.1; the composite antifreeze agent includes sodium nitrite and urea in a mass ratio of 2:1. Waterproofing and sealing agents include a deep-penetrating crystallizing sealing waterproofing agent, cetyl phosphate-cetyl phosphate diethanolamine, and expanded fiber crack-resistant waterproofing agent in a mass ratio of 2.0:0.5:0.5. Thermal insulation and stabilizing agents include montmorillonite and fluorocarbon surfactants in a mass ratio of 0.8:0.1.

[0050] The preparation method of the above-mentioned lightweight building material containing distiller's grains includes the following steps:

[0051] S1: According to the mass fraction of raw materials, ordinary silicate cement, composite activated powder, graded expanded perlite, shale ceramsite, modified reinforcing fiber and sodium sulfate are mixed at 60 rpm for 3 min. Then, weather-resistant reinforcing agent, waterproof sealing agent, thermal insulation stabilizing agent and polycarboxylate superplasticizer are added, and the mixture is continued to be mixed at 60 rpm for 3 min. Then, a mixture of premixed methyl ethylene oxide and ethylene oxide dimethyl ether polymer and water is added, and the mixture is continued to be mixed at 60 rpm for 2 min. Finally, a composite foaming agent is added, and the mixture is mixed at 80 rpm for 4 min to form a foam slurry, thus obtaining a lightweight building material.

[0052] S2: Inject lightweight building materials into precast component molds or on-site casting molds, vibrate at a frequency of 45Hz to compact the material for 30 seconds, cover the surface with a plastic film, allow to cure naturally for 10 hours, demold, and spray with water (5L / m² every 8 hours). 2 Leave it in the oven for 7 days, then allow it to rest naturally for 28 days.

[0053] In this embodiment, the test sample was cast using a precast component mold that meets the test specifications.

[0054] Example 3

[0055] A lightweight building material containing distiller's grains comprises the following raw materials in parts by weight: 29 parts ordinary silicate cement, 18 parts composite activated powder, 3.5 parts modified reinforcing fiber, 3.5 parts composite foaming agent, 18 parts graded expanded perlite, 9 parts shale ceramsite, 5 parts weather-resistant reinforcing agent, 2 parts waterproof sealing agent, 3 parts thermal insulation stabilizing agent, 0.6 parts sodium sulfate, 1.2 parts polycarboxylate superplasticizer, 0.1 parts polymer of methyl ethylene oxide and ethylene oxide dimethyl ether, and 28 parts water.

[0056] The preparation method of the composite activated powder includes: drying corn distillers' grains to a moisture content of 5 wt%, pulverizing to a D50 of 50 μm, and passing through a 100-mesh sieve. Pulverizing slag and passing it through a 150-mesh sieve. Mixing the distillers' grains, slag powder, expandable graphite powder, and nano-silica at a mass ratio of 4:4:0.1:0.3 to obtain a mixture. Preparing a 2 wt% silane coupling agent KH-560 solution with a 20 vol% ethanol aqueous solution to obtain a modifier. Adding the mixture to the modifier at a solid-liquid mass ratio of 1:3, stirring at 60℃ for 0.5 h, drying at 150℃ to a moisture content of 3 wt%, pulverizing and passing through a 100-mesh sieve to obtain the composite activated powder.

[0057] The preparation method of the modified reinforced fiber includes: melt extruding glass fiber reinforced PP through an extruder, granulating it, and producing short fibers with a diameter of 0.5 mm and a length of 5 mm. A solution of 1.5 wt% silane coupling agent KH-550 is prepared using a 25 vol% ethanol aqueous solution, and the pH is adjusted to 4 with an 8 wt% acetic acid aqueous solution. The solution is then stirred and pre-hydrolyzed at 30°C for 20 min to obtain a modified solution. The short fibers are immersed in the modified solution at a material-to-solution mass ratio of 1:8, stirred at 20°C for 2 h, filtered through a 150-mesh sieve, and the filter cake is dried in an air-drying environment at 90°C for 4 h to obtain the modified reinforced fiber.

[0058] The preparation method of the composite foaming agent includes: taking the waste liquor of distillers' grains from corn raw materials, filtering to remove impurities, and adjusting the protein content to 20wt%. The liquor is mixed according to the mass ratio of distillers' grains protein liquid: ammonium bicarbonate: lignocellulose: Tween-80 = 3:1.5:0.3:0.2, and stirred at 50℃ and 350rpm for 1 hour to obtain the composite foaming agent.

[0059] The graded expanded perlite includes coarse expanded perlite with a particle size of 20-40 mesh and fine expanded perlite with a particle size of 60-80 mesh, with a mass ratio of 3:1. The shale ceramsite has a particle size range of 3mm-8mm. Weather-resistant reinforcing agents include silica fume, a composite antifreeze agent, and UV-328 in a mass ratio of 3:0.8:0.2; the composite antifreeze agent includes sodium nitrite and urea in a mass ratio of 1:1.5. Waterproofing and sealing agents include a deep-penetrating crystallizing sealing waterproofing agent, cetyl phosphate-cetyl phosphate diethanolamine, and expanded fiber crack-resistant waterproofing agent in a mass ratio of 1.5:0.8:0.3. Thermal insulation and stabilizing agents include montmorillonite and fluorocarbon surfactants in a mass ratio of 1.5:0.2.

[0060] The preparation method of the above-mentioned lightweight building material containing distiller's grains includes the following steps:

[0061] S1: According to the mass fraction of raw materials, ordinary silicate cement, composite activated powder, graded expanded perlite, shale ceramsite, modified reinforcing fiber and sodium sulfate are mixed at 80 rpm for 2 min. Then, weather-resistant reinforcing agent, waterproof sealing agent, thermal insulation stabilizing agent and polycarboxylate superplasticizer are added, and the mixture is continued to be mixed at 80 rpm for 2 min. Then, a mixture of premixed methyl ethylene oxide and ethylene oxide dimethyl ether polymer and water is added, and the mixture is continued to be mixed at 80 rpm for 1 min. Finally, a composite foaming agent is added, and the mixture is mixed at 100 rpm for 2 min to form a foam slurry, thus obtaining a lightweight building material.

[0062] S2: Inject lightweight building materials into precast component molds or on-site casting molds, vibrate at a frequency of 50Hz to compact the material for 20 seconds, cover the surface with a plastic film, allow to cure naturally for 12 hours, demold, and spray with water (4L / m² every 8 hours). 2 Leave it in the oven for 7 days, then allow it to rest naturally for 28 days.

[0063] In this embodiment, the test sample was cast using a precast component mold that meets the test specifications.

[0064] The indicators and sources involved in the above embodiments are as follows: Ordinary Portland cement is ordinary Portland cement P·O42.5R, sourced from Tangshan Development Cement Co., Ltd. Slag powder is S95 mineral powder, sourced from Taixing Suye New Building Materials Co., Ltd. Expandable graphite powder is 2000 mesh grade, sourced from Shijiazhuang Huabang Mineral Products Co., Ltd. Nano-silica, 12nm grade, sourced from Lingshou Shuanglong Mining Co., Ltd. Silane coupling agent KH-560 and silane coupling agent KH-550 are both sourced from Shandong Huachen New Materials Co., Ltd. Glass fiber reinforced PP is 30wt% glass fiber reinforced PP, sourced from Dongguan Nabaichuan Plastics Co., Ltd. Ammonium bicarbonate purity is 99%. Wood fiber is from Lingshou Xingyuan Mineral Powder Processing Plant, flocculent wood fiber for construction, model 089. Tween-80 purity is 99%. Expanded perlite is from Guangzhou Wanjie Building Materials Co., Ltd. Shale ceramsite is from Jinzhou Xinghong New Building Materials Co., Ltd. Silica fume, 1250 mesh, sourced from Lingshou County Zhanteng Mineral Products Processing Plant. UV-328 is an ultraviolet absorber, 99% pure. Sodium nitrite, 99% pure. Urea, 99% pure. Deep-penetrating crystallizing sealing and waterproofing agent, model CM-DPS, sourced from Henan Juneng Hezhong Special Materials Co., Ltd. Cetyl phosphate-cetyl phosphate diethanolamine, 99% pure, sourced from Suzhou Senfida Chemical Co., Ltd. Expanded fiber crack-resistant waterproofing agent, model SY-K, sourced from Henan Juneng Hezhong Special Materials Co., Ltd. Montmorillonite, 325 mesh grade, sourced from Lingshou County Aotai Mineral Products Processing Plant. Fluorocarbon surfactant, model FS-8500, sourced from Guangzhou Huitu New Materials Co., Ltd. Sodium sulfate, 99% pure. Polycarboxylate superplasticizer, model PC8800, sourced from Jiangsu Guanxiang Building Materials Co., Ltd. The polymer of methyl ethylene oxide and ethylene oxide dimethyl ether is PEG / PPG-14 / 7 dimethyl ether, which is sourced from Guangdong Wengjiang Chemical Reagent Co., Ltd., with a purity of 99%.

[0065] Comparative Example 1

[0066] The difference from Example 1 is that in the preparation of the composite activated powder, the mass ratio of distiller's grains: slag powder: expandable graphite powder: nano silica is 2:6.5:0.2:0.2, and no surface modification with silane coupling agent KH-560 is performed.

[0067] Comparative Example 2

[0068] The difference from Example 1 is that in the material formulation, the modified reinforcing fiber is directly replaced by short fiber, without modification by silane coupling agent KH-550.

[0069] Comparative Example 3

[0070] The difference from Example 1 is that the polymer of methyl ethylene oxide and ethylene oxide dimethyl ether is not added to the material formulation.

[0071] Comparative Example 4

[0072] The difference from Example 1 is that the polymer of methyl ethylene oxide and ethylene oxide dimethyl ether is mixed in the preparation of the composite foaming agent and stirred with the composite foaming agent at 55°C and 320 rpm for 1 hour to obtain the composite foaming agent.

[0073] Comparative Example 5

[0074] The difference from Example 1 is that in the preparation of the composite foaming agent, the mass ratio of distillers' grains protein solution: ammonium bicarbonate: lignocellulose: Tween-80 is 1.2:4:0.4:0.15.

[0075] Comparative Example 6

[0076] The difference from Example 1 is that all waterproofing and sealing agents used are deep-penetrating crystallizing sealing and waterproofing agents.

[0077] Comparative Example 7

[0078] The difference from Example 1 is that all waterproofing and sealing agents used are cetyl phosphate-cetyl diethanolamine.

[0079] Comparative Example 8

[0080] The difference from Example 1 is that all waterproof sealing agents are expanded fiber anti-crack waterproof agents.

[0081] Comparative Example 9

[0082] The difference from Example 1 is that in the waterproof sealing agent, the mass ratio of deep penetration crystallizing sealing waterproof agent: cetyl phosphate-cetyl phosphate diethanolamine: expandable fiber anti-crack waterproof agent is 0.4:0.7:1.8.

[0083] 1. 28-day compressive strength test:

[0084] Test block specifications: 100mm×100mm×100mm, 28-day curing.

[0085] The testing method includes: using a universal testing machine, uniformly loading the specimen until failure, and recording the maximum failure load F (N). The compressive strength fc = F / A, where A is the area of ​​the specimen subjected to pressure (mm²). 2 ).

[0086] 2. 28-day flexural strength test:

[0087] Test block specifications: 100mm×100mm×400mm, 28-day curing.

[0088] The testing method includes: using the three-point bending method, with a span of 300 mm, uniformly loading until the specimen breaks, and recording the maximum failure load F (N). Flexural strength ff = (3FL) / (2bh) 2 ), where L is the span, b is the width of the test block, and h is the height of the test block.

[0089] 3. 24-hour water absorption rate test:

[0090] Test block specifications: 100mm×100mm×100mm, 28-day curing.

[0091] The testing method includes: drying the sample block to constant weight and weighing the dried mass md (g). Completely immersing the sample block in 25℃ clean water for 24 hours, ensuring the sample block does not contact the bottom or side walls of the container during this time. Removing the sample block and gently wiping off any surface moisture with a damp cloth. Immediately weighing the saturated mass mw (g) using a balance. Water absorption rate Wm = (mw - md) / md × 100%.

[0092] 4. Permeability test:

[0093] Test block specifications: a frustum-shaped test block with an upper opening of φ175mm, a lower opening of φ185mm, and a height of 150mm.

[0094] The testing method includes: curing the test blocks for 26 days (i.e., 2 days in advance), sealing the sides of 6 test blocks with molten paraffin wax, and installing them into the membrane of the permeability tester; starting from a water pressure of 0.1 MPa, increasing the water pressure by 0.1 MPa every 8 hours, and continuing to pressurize until water seepage occurs in 3 test blocks, and recording the water pressure P (MPa) at this time.

[0095] 5. Freeze-resistance test:

[0096] Test block specifications: 100mm×100mm×100mm.

[0097] The testing method includes: curing the test blocks to 24 days (i.e., 4 days in advance), then immersing them in 20℃ water for 4 days (reaching a total age of 28 days), serving as freeze-thaw test blocks. Simultaneously, a control test block cured normally for 28 days was set up, and the initial compressive strength f0 (MPa) of the control test block was tested. The freeze-thaw test blocks were placed in a freeze-thaw test chamber, with one cycle consisting of freezing at -20℃ for 4 hours and thawing in 20℃ water for 4 hours, for a total of 50 cycles. After the cycles were completed, the final compressive strength f1 (MPa) was tested. The strength loss rate Δfc = (f0 - f1) / f0 × 100%.

[0098] For all the above test items, three parallel tests were set up, and the average value was taken. The test results are shown in Table 1 below.

[0099] Table 1. Test Results (Average Values)

[0100]

[0101] In the materials of Examples 1 to 3, the composite activating powder, composite foaming agent, foam stabilizer, lightweight aggregate, waterproofing agent, and weathering agent are all used in optimal proportions. This ensures that the active ingredients, such as distiller's grains, fully react to form dense hydrates, while the graded aggregate and stable foam form a uniform microporous structure, achieving both lightweight and high strength. The composite activating powder is modified with KH-560, and the reinforcing fibers are modified with KH-550, effectively improving the interfacial adhesion between the powder, fibers, and cementitious base, reducing agglomeration and pore defects, and enhancing mechanical properties and structural stability. Based on the overall composition characteristics of the material, a waterproofing and sealing agent with a reasonable combination of crystalline, hydrophobic, and crack-resistant types is designed, along with thermal insulation and weathering agents to work synergistically, sealing capillary pores, inhibiting cracks, and preventing moisture intrusion. The polymer of methyl ethylene oxide and ethylene oxide dimethyl ether is precisely added at the right time to optimize dispersibility and foam stability, further improving structural density. The mixing speed, curing method, and other processes are matched with the formula to ensure that all components are fully mixed and the hydration reaction is complete, ultimately achieving a balanced optimization of strength, water resistance, and freeze resistance.

[0102] In Comparative Example 1, the composite activated powder had an unbalanced ratio and was unmodified. The synergistic effect of distillers' grains and slag powder in the composite activated powder depends on a reasonable ratio. The active components in the distillers' grains need to fully react with the hydration products of the slag powder to form dense hydrates. An unbalanced ratio leads to a lack of active ingredients and a decrease in the density of the material structure. At the same time, the modification effect of the silane coupling agent improves the compatibility between the powder and the cementitious matrix interface through chemical bonding. Without modification, the powder will agglomerate, weaken the interfacial bonding force, and increase the porosity. Interfacial defects and increased porosity will trigger a series of performance degradations. The loose structure leads to a decrease in mechanical properties, and the increased pore connectivity promotes water penetration, resulting in increased water absorption and poor impermeability. During freeze-thaw cycles, the loose interface is prone to stress concentration, which exacerbates the loss of mass and strength.

[0103] In Comparative Example 2, the glass fiber reinforced PP fibers were not modified with a silane coupling agent. The reinforcing effect of the fibers relies primarily on their interfacial bond with the cement matrix. The silane coupling agent KH-550 can form chemical bonds between the fibers and the matrix, improving the anchoring effect and load transfer efficiency of the fibers, effectively inhibiting crack propagation, and promoting uniformity. Without modification, the fiber surface is smooth, and the contact with the matrix is ​​only physical, failing to achieve efficient stress transfer. This significantly weakens the inhibition of crack propagation, resulting in localized defects and a decrease in compressive and flexural strength. Furthermore, the loose interfacial bond creates micropores, providing channels for water penetration, leading to increased water absorption and deterioration of frost resistance.

[0104] Comparative Example 3 shows the polymer without added methyl ethylene oxide and ethylene oxide dimethyl ether. Adding a high proportion of polymer during material mixing provides dispersion, foam stabilization, and interface modification functions. It disperses cement particles and aggregates, reducing large pores caused by agglomeration, and optimizes foam stability, resulting in uniform and fine bubbles and improved structural density. Adding a high proportion of polymer early in the material mixing process, rather than adding it to the composite foaming agent, reduces the impact on the foaming agent composition and achieves suitable foam stabilization performance. Without addition, the cement-based material exhibits poor dispersibility, and the foam easily breaks down, forming interconnected pores. This increased pore connectivity leads to increased water absorption and deterioration of impermeability. Simultaneously, increased interface defects hinder load transfer, resulting in decreased compressive and flexural strength. During freeze-thaw cycles, interconnected pores become channels for moisture migration, exacerbating freeze-thaw damage and further amplifying strength loss.

[0105] In Comparative Example 4, a high proportion of the polymer was mixed with the composite foaming agent in advance. The optimal time for the polymer to act is during the later stage of cement-based slurry mixing. Excessive polymer mixed with the foaming agent too early will cause it to adsorb onto the surface of the foaming agent molecules, especially affecting the foaming properties of distillers' grains protein, thus damaging the foaming rate and stability of the foam, causing bubbles to merge and grow larger, increasing porosity and uneven pore size distribution. At the same time, the dispersing effect of the polymer is weakened, and the agglomeration of cement-based materials is aggravated. These two factors lead to an increase in internal structural defects in the material, resulting in a decrease in compressive and flexural strength. Increased pore connectivity makes it easier for water to penetrate, and the water absorption rate, impermeability, and freeze-thaw resistance are all significantly deteriorated. The degree of performance degradation is even higher than in the case where no polymer is added.

[0106] In Comparative Example 5, the composite foaming agent formulation was unbalanced. In the composite foaming agent, the distillers' grains protein solution plays a dual role in promoting foaming and stabilizing it, forming a liquid film to prevent bubble rupture. Ammonium bicarbonate, as a foaming agent, decomposes to produce gas; the ratio of the two must be precisely matched. When the ratio is unbalanced, insufficient protein content leads to poor foam stability, causing bubbles to easily merge and collapse, forming numerous large pores. Excessive ammonium bicarbonate decomposes to produce too much gas, resulting in excessively high and unevenly distributed porosity within the material, significantly reducing its structural load-bearing capacity. Large pores and interconnected pores not only reduce mechanical properties but also facilitate water penetration, leading to a significant increase in water absorption, severely insufficient impermeability, and more severe damage caused by water retention during freeze-thaw cycles.

[0107] In Comparative Examples 6 to 9, the waterproofing and sealing additives were used alone or in an unbalanced ratio. The core function of the waterproofing and sealing additives relies on the synergistic effect of three components: a deep-penetrating crystalline sealing waterproofing agent that penetrates into the material and reacts with hydration products to form crystals, sealing capillary pores; a cetyl phosphate-cetyl diethanolamine phosphate that forms a hydrophobic film on the surface to prevent water intrusion; and an expanded fiber crack-resistant waterproofing agent that inhibits the formation and propagation of cracks, preventing water from penetrating through cracks. When a single component is used, there is a lack of synergistic effect. Using only a crystalline additive results in a limited amount of crystal formation, which cannot completely cover all pores; using only a surface hydrophobic additive cannot seal internal capillary pores and micro-cracks; and using only a crack-resistant additive has no obvious hydrophobic and crystalline sealing effect. Inverted ratios lead to insufficient crystalline sealing and surface hydrophobic effects, while excessive crack resistance cannot compensate for waterproofing defects, ultimately resulting in increased water absorption and deterioration of impermeability and frost resistance.

Claims

1. A lightweight building material containing distiller's grains, characterized in that, The materials include the following raw materials in parts by weight: 24-29 parts ordinary Portland cement, 18-23 parts composite activated powder, 2.5-3.5 parts modified reinforcing fiber, 3.5-5.0 parts composite foaming agent, 14-18 parts graded expanded perlite, 9-13 parts shale ceramsite, 3-5 parts weather-resistant reinforcing agent, 2-3 parts waterproofing and sealing agent, 2-3 parts thermal insulation and stabilizing agent, 0.6-1.0 parts sodium sulfate, and 0.8-1.2 parts polycarboxylate superplasticizer. The polymer of methyl ethylene oxide and ethylene oxide dimethyl ether comprises 0.1 to 0.15 parts and water comprises 23 to 28 parts; the preparation method of the composite activated powder includes: mixing distiller's grains, slag powder, expandable graphite powder and nano silica in a mass ratio of (4 to 6): (3 to 4): (0.1 to 0.3): (0.1 to 0.3) to obtain a mixture; preparing a 1.5 wt% to 2 wt% silane coupling agent KH-560 solution with an ethanol aqueous solution to obtain a modifier; according to the solid-liquid... The mass ratio is 1:(2-3). The mixture is added to the modifier, stirred, dried, and pulverized through a 100-150 mesh sieve to obtain composite activated powder. The preparation method of the modified reinforcing fiber includes: melt-extruding glass fiber reinforced PP, granulating it, and producing short fibers with a diameter of 0.3mm-0.5mm and a length of 5mm-8mm; preparing a 1.5wt%-2.5wt% silane coupling agent KH-550 solution with an ethanol aqueous solution, adjusting the pH to 4-5, stirring for pre-hydrolysis, and obtaining the modified liquid. The short fibers are immersed in the modified liquid at a material-to-liquid mass ratio of 1:(6-8), stirred, filtered, and the filter cake is dried to obtain modified reinforced fibers. The preparation method of the composite foaming agent includes: mixing the ingredients at a mass ratio of distillers' grains protein liquid:ammonium bicarbonate:wood fiber:Tween-80 = (3-5):(1-1.5):(0.3-0.5):(0.1-0.2), stirring at 50℃-60℃ and 300rpm-350rpm for 1h-1.5h to obtain the composite foaming agent.

2. The lightweight building material containing distiller's grains according to claim 1, characterized in that, The graded expanded perlite includes coarse expanded perlite with a particle size of 20-40 mesh and fine expanded perlite with a mass ratio of (2-3):(1-1.5); the shale ceramsite has a particle size range of 3 mm to 8 mm.

3. The lightweight building material containing distiller's grains according to claim 1, characterized in that, The weather-resistant enhancement agent comprises silica fume, a composite antifreeze agent, and UV-328 in a mass ratio of (2-3):(0.8-1.2):(0.1-0.2); the composite antifreeze agent comprises sodium nitrite and urea in a mass ratio of (1-2):(1-1.5).

4. A lightweight building material containing distiller's grains according to claim 1, characterized in that, The waterproofing and sealing agent includes a deep-penetrating crystallizing sealing and waterproofing agent, a cetyl phosphate-cetyl phosphate diethanolamine, and an expanding fiber anti-crack waterproofing agent in a mass ratio of (1.5-2.0):(0.5-0.8):(0.3-0.5).

5. A lightweight building material containing distiller's grains according to claim 1, characterized in that, The thermal insulation and stabilizing agent comprises montmorillonite and fluorocarbon surfactant in a mass ratio of (0.8-1.5):(0.1-0.2).

6. The method for preparing a lightweight building material containing distiller's grains as described in claim 1, characterized in that, The process includes the following steps: S1: Mix ordinary silicate cement, composite activated powder, graded expanded perlite, shale ceramsite, modified reinforcing fiber, and sodium sulfate according to the mass proportions of the raw materials. Then add weather-resistant reinforcing agent, waterproof sealing agent, thermal insulation stabilizing agent, and polycarboxylate superplasticizer, and continue mixing. Then add a mixture of premixed methyl ethylene oxide and ethylene oxide dimethyl ether polymer and water, and continue mixing. Finally, add a composite foaming agent and mix to form a foam slurry with an air content of 50 vol% to 60 vol%, thus obtaining lightweight building materials; S2: Inject the lightweight building materials into precast component molds or on-site casting molds, vibrate to compact the material, cover the surface with plastic film, and cure naturally for 10 to 12 hours. Demold, water spray curing for 7 days, and then cure naturally for 28 days.

7. The application of the lightweight building material containing distiller's grains as described in claim 1, characterized in that, The lightweight building materials are used in the preparation of non-load-bearing walls, prefabricated insulation components, underfloor heating backfill layers, or sound insulation and noise reduction components in building engineering.

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