Solid waste-based cementing material lightweight roof and method

Abstract

The invention discloses a solid-waste-based cementing material lightweight roof and a method, and relates to the technical field of building materials.The solid-waste-based cementing material lightweight roof comprises a building roof base layer, a vapor barrier layer, a lightweight functional layer, a waterproof layer and a protective surface layer which are sequentially arranged, and the method comprises the steps that solid-waste-based cementing material dry powder, an alkali activator solution and water are mixed and stirred to form uniform slurry; the method comprises the following steps: preparing a foaming agent solution into prefabricated foam through physical foaming, introducing the prefabricated foam into slurry, mixing to obtain solid-waste-based foam gelling light slurry, and preparing the solid-waste-based foam gelling light slurry in a manner of on-site integral pouring molding or prefabricated part on-site assembly molding. A light functional layer with set gradient and thickness is constructed on the building roof base layer; and the molded light functional layer is cured to be hardened to preset performance, so that the problem that the existing solid waste-based light material and components thereof are difficult to directly meet the multifunctional integrated requirements of building roofs on light weight, slope making, heat preservation, bearing, system waterproofing and the like is solved.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a lightweight roof made of solid waste-based cementitious material and its method. Background Technology

[0002] In the context of building energy conservation and the dual-carbon strategy, developing lightweight, heat-insulating, and low-carbon roofing systems is of great significance. Traditional roofing structures often use cement-based materials for on-site slope creation, supplemented by insulation panels, which suffers from problems such as heavy weight, complex processes, significant thermal bridging effects, and high carbon emissions from cement. Utilizing industrial solid wastes such as fly ash and slag to prepare alkali-activated cementitious materials provides a pathway to replace cement and realize the resource utilization of solid waste.

[0003] Existing technologies include various studies on the preparation of solid waste-based lightweight materials using the alkali activation principle. For example, invention patent CN113264717B discloses a method for preparing high-volume solid waste-based alkali-activated foamed concrete precast components. This method uses phosphorus slag and coal gangue powder as the main cementing materials, combined with specifically graded solid waste ceramsite, and employs a composite chemical foaming agent to prepare high-volume solid waste precast components primarily used for walls. This technical solution embodies the idea of ​​utilizing solid waste in large quantities.

[0004] However, directly applying solid waste-based material technologies derived from wall requirements to building roofing projects faces significant technological mismatch issues: Functional requirements differ: Roofing systems require functional layers to integrate multiple functions, including drainage, slope establishment, thermal insulation, load-bearing capacity, and reliable bonding with the waterproofing layer. Existing wall component technologies focus on meeting the load-bearing, sound insulation, or self-insulating requirements of the walls; their material performance design and component forms are not optimized for the drainage, systematic waterproofing, and weather resistance requirements of roofs. Insufficient system construction and construction adaptability: Simply using prefabricated components for roofing presents problems such as complex waterproofing treatment of slab joints, difficulty in accurately controlling the overall drainage slope, and poor adaptability to complex roof shapes, easily leading to potential leakage risks. If on-site casting is used, existing alkali-activated systems based on chemical foaming or simple physical foaming often fail to meet the workability, setting time control, and volume stability requirements of large-area thin-layer construction for roofing projects. Lack of systematic solutions for roofing projects: Existing technologies mostly focus on material formulations or single component products, lacking integrated technical solutions that take a holistic approach to roofing system engineering, encompassing the performance design of specialized materials, the selection of diversified construction techniques, and the synergistic performance with vapor barriers, waterproofing layers, and other components.

[0005] Therefore, there is an urgent need for a solid waste-based lightweight material and application technology specifically designed for building roofing projects, which can achieve multi-functional integration, convenient construction, and reliable system. Summary of the Invention

[0006] Based on this, and in response to the above problems, this invention proposes a lightweight roof and method based on solid waste-based cementitious materials, which solves the problem that current lightweight solid waste-based materials and their components cannot directly meet the multi-functional integrated requirements of building roofs for lightweight, slope finding, heat insulation, load-bearing capacity and system waterproofing.

[0007] The technical solution of this invention is: A lightweight roof made of solid waste-based cementitious material includes a building roof base layer and a lightweight functional layer disposed on the building roof base layer. The lightweight functional layer is a structural layer made of solid waste-based foam cementitious material with a dry density of 600-1000 kg / m³, a 28-day compressive strength of 3.0-10.0 MPa, and a thermal conductivity of 0.12-0.20 W / (m·K).

[0008] Preferably, a vapor barrier is provided between the building roof base layer and the lightweight functional layer; a waterproof layer and a protective surface layer are sequentially provided above the lightweight functional layer.

[0009] A method for preparing a lightweight roof made of solid waste-based cementitious material, comprising the following steps: S1. Preparation of alkali-activated slurry: Mix and stir the solid waste-based cementitious material dry powder with alkali activator solution and water to form a uniform alkali-activated slurry; wherein, the solid waste-based cementitious material dry powder includes fly ash and granulated blast furnace slag powder, and the alkali activator solution is a composite solution of water glass and sodium hydroxide with a modulus of 1.2-1.8; S2. Preparation of solid waste-based foamed gel lightweight slurry: The foaming agent solution is physically foamed to form pre-foam, and the pre-foam is introduced into the uniform alkali-activated slurry obtained in step S1. After uniform mixing, a solid waste-based foamed gel lightweight slurry with a wet apparent density of 800-1200 kg / m³ is obtained. S3. Constructing the roof functional layer: The solid waste-based foam cementitious lightweight slurry obtained in step S2 is used to construct a lightweight functional layer with slope and thickness on the building roof base layer by casting it on-site as a whole or assembling it on-site with prefabricated components. S4. Maintenance: Maintain the lightweight functional layer after molding.

[0010] Preferably, the mass ratio of fly ash to granulated blast furnace slag powder in the solid waste-based cementitious material dry powder is (50%-70%):(30%-50%); and the amount of alkali activator solution used is 4%-8% of the total mass of the solid waste-based cementitious material dry powder, calculated as Na2O.

[0011] Preferably, in step S1, a polycarboxylate superplasticizer and a cellulose ether-based foam stabilizer are also added; the amount of polycarboxylate superplasticizer added is 0.2%-0.8% of the total mass of the solid waste-based cementitious material dry powder, and the amount of cellulose ether-based foam stabilizer added is 0.1%-0.3% of the total mass of the solid waste-based cementitious material dry powder.

[0012] Preferably, in step S1, a synthetic fiber with a volume content of 0.1%-0.3% is added, wherein the synthetic fiber is either polypropylene fiber or polyvinyl alcohol fiber.

[0013] Preferably, in step S2, the density of the pre-made foam is 40-60 kg / m³; in step S3, the molding thickness of the lightweight functional layer is 50-200 mm, and the drainage slope formed on its surface is 1%-5%.

[0014] Preferably, in step S3, on-site integral casting refers to directly pouring solid waste-based foam cementitious lightweight slurry onto the working surface of the building roof base layer, and then spreading, leveling and compacting it to form an integral and seamless lightweight functional layer; on-site assembly of precast components refers to pouring solid waste-based foam cementitious lightweight slurry into a mold, curing and demolding it to form precast components, and then laying the precast components on the building roof base layer and treating the joints to form a spliced ​​lightweight functional layer.

[0015] Preferably, in step S4, the curing includes: immediately covering and sealing the surface for 24-48 hours before and after the initial setting of the lightweight functional layer, followed by wet curing under conditions where the relative humidity is not less than 90%, for a period of not less than 7 days.

[0016] Preferably, the precast components are cured in the mold using steam at a temperature of 30-60℃ for 12-24 hours.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Achieves integrated roof functions: This invention creatively integrates slope finding, insulation, and load-bearing functions into a single lightweight functional layer. Through precise design of material properties, it meets the comprehensive needs of roof projects and simplifies the structural layers.

[0018] 2. This invention specifically overcomes the application bottlenecks of existing solid waste-based technologies: Compared to precast solid waste-based components mainly used for walls in the background technology, this invention not only selects the mainstream fly ash and slag system, which is more suitable for roofs, but more importantly, it proposes a dual-mode construction method and corresponding system structure that closely matches the roof's drainage, waterproofing, and weather resistance characteristics, combining on-site integral casting and precast assembly. This effectively solves the inherent problems of difficulty in achieving slope, weak joint waterproofing, and poor system adaptability when wall component technology is applied to roofs, representing a substantial innovation for different application fields.

[0019] 3. Excellent construction flexibility and reliability: The dual-mode construction strategy allows this invention to flexibly adapt to the different project schedules, costs, and technical requirements. Strict control of slurry performance and targeted curing procedures ensure the reliability of construction quality and the stability of the final product performance.

[0020] 4. It has generated significant resource and environmental benefits: The main materials consume a large amount of industrial solid waste, reducing cement usage and carbon emissions. The integrated lightweight structure further reduces the building's structural load and lowers energy consumption during building operation due to its excellent thermal insulation performance, resulting in significant green benefits throughout its entire life cycle. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the layer structure of a lightweight roof made of solid waste-based cementitious material, as described in an embodiment of the present invention. Figure 2 This is a schematic flowchart of a method for preparing a lightweight roof based on solid waste cementitious materials, as described in an embodiment of the present invention. Explanation of reference numerals in the attached figures: 10-Building roof base layer, 11-Lightweight functional layer, 12-Vacuum barrier, 13-Waterproof layer, 14-Protective surface layer. Detailed Implementation

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0027] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Example: like Figure 1As shown, this embodiment discloses a lightweight roof made of solid waste-based cementitious material, including a building roof base layer 10 and a lightweight functional layer 11 disposed on the building roof base layer 10. The lightweight functional layer 11 is a structural layer made of solid waste-based foam cementitious material with a dry density of 600-1000 kg / m³, a 28-day compressive strength of 3.0-10.0 MPa, and a thermal conductivity of 0.12-0.20 W / (m·K).

[0031] Among them, a vapor barrier 12 is provided between the building roof base layer 10 and the lightweight functional layer 11; a waterproof layer 13 and a protective surface layer 14 are sequentially provided above the lightweight functional layer 11.

[0032] like Figure 2 As shown, a method for preparing a lightweight roof made of solid waste-based cementitious material includes the following steps: S1. Preparation of alkali-activated slurry: Mix and stir the solid waste-based cementitious material dry powder with alkali activator solution and water to form a uniform alkali-activated slurry; wherein, the solid waste-based cementitious material dry powder includes fly ash and granulated blast furnace slag powder, and the alkali activator solution is a composite solution of water glass and sodium hydroxide with a modulus of 1.2-1.8; In step S1, during mixing and stirring, a polycarboxylate superplasticizer and a cellulose ether-based foam stabilizer are also added. The amount of polycarboxylate superplasticizer added is 0.2%-0.8% of the total mass of the solid waste-based cementitious material dry powder, and the amount of cellulose ether-based foam stabilizer added is 0.1%-0.3% of the total mass of the solid waste-based cementitious material dry powder.

[0033] During the mixing and stirring in step S1, synthetic fibers with a volume content of 0.1%-0.3% are also added. The synthetic fibers are either polypropylene fibers or polyvinyl alcohol fibers.

[0034] The modulus of 1.2-1.8 refers to the molar ratio of silicon dioxide (SiO2) to sodium oxide (Na2O) in the composite solution of water glass and sodium hydroxide, which is 1.2-1.8. This range represents an optimized window verified through extensive experiments, finding the best balance point for the specific goal of preparing lightweight roofing layers using fly ash and slag systems and physical foaming. Within this range, the activity of fly ash and slag is effectively activated, while the slurry exhibits good fluidity and can be uniformly mixed with foam. Sufficient working time allows for timely hardening and reduces the risk of cracking, which is crucial for large-area roofs, ultimately forming a structurally stable gel.

[0035] S2. Preparation of solid waste-based foamed gel lightweight slurry: The foaming agent solution is physically foamed to form pre-foam, and the pre-foam is introduced into the uniform alkali-activated slurry obtained in step S1. After uniform mixing, a solid waste-based foamed gel lightweight slurry with a wet apparent density of 800-1200 kg / m³ is obtained. The density of precast foam is 40-60 kg / m³.

[0036] S3. Constructing the roof functional layer: The solid waste-based foam cementitious lightweight slurry obtained in step S2 is used to construct a lightweight functional layer 11 with a set slope and thickness on the building roof base layer 10 by casting it on site as a whole or assembling it on site with prefabricated components. The lightweight functional layer 11 has a molding thickness of 50-200mm, and its surface has a drainage slope of 1%-5%. On-site integral casting refers to the direct pouring of solid waste-based foam cementitious lightweight slurry onto the working surface of the building roof base layer 10, followed by spreading, leveling and compaction to form an integral and seamless lightweight functional layer 11; On-site assembly of precast components refers to pouring solid waste-based foam cementitious lightweight slurry into a mold, curing and demolding it to form precast components, and then laying the precast components on the building roof base layer 10 and treating the joints to form a spliced ​​lightweight functional layer 11.

[0037] The precast components are cured in the mold using steam at a temperature of 30-60℃ for 12-24 hours.

[0038] S4. Curing: Curing the formed lightweight functional layer 11 to harden it to the predetermined performance.

[0039] Preferably, the mass ratio of fly ash to granulated blast furnace slag powder in the solid waste-based cementitious material dry powder is (50%-70%):(30%-50%); and the amount of alkali activator solution used is 4%-8% of the total mass of the solid waste-based cementitious material dry powder, calculated as Na2O.

[0040] The curing process includes: immediately covering and sealing the surface of the lightweight functional layer 11 before and after initial setting for 24-48 hours, followed by wet curing under conditions where the relative humidity is not less than 90%, for a period of not less than 7 days.

[0041] This invention creatively integrates slope finding, thermal insulation, and load-bearing functions into a single lightweight functional layer 11. Its core lies in the synergistic effect of a specific ratio of fly ash and slag composite system with a precisely modulated alkali activator, achieving efficient and stable activation of solid waste activity and ensuring good workability and reaction balance of the slurry. Based on this, by introducing highly stable physical pre-fabricated foam and precisely controlling its dosage, the wet density of the slurry becomes a key means of controlling the dry density, strength, and thermal conductivity of the final product, thus perfectly achieving an integrated performance design of lightweight, high strength, and thermal insulation at the material level. Crucially, this invention proposes a dual-mode construction method—on-site integral casting and prefabrication assembly—deeply compatible with the characteristics of roof engineering, supplemented by a dedicated curing system of covering, sealing, and strict moisture control. This not only effectively solves the inherent bottlenecks faced by traditional wall component technologies when applied to roofs, such as difficulty in slope control, weak joint waterproofing, and poor system adaptability, but also endows the technical solution with excellent construction flexibility and engineering reliability. Ultimately, by maximizing the use of industrial solid waste to replace cement, this technology system constructs a complete and efficient roof structure that includes vapor barriers, functional layers, waterproofing, and protection. This not only significantly reduces structural loads and lowers carbon emissions during building material production and operation, but also simplifies structural layers, demonstrating outstanding resource, environmental, and economic benefits throughout the entire life cycle.

[0042] The following describes specific embodiments using two different modes: Example 1: Construction of lightweight thermal insulation slope-forming layer by on-site integral casting This example demonstrates the construction of a reinforced concrete flat roof using an on-site monolithic casting method.

[0043] Objectives and Design: To construct an integrated lightweight functional layer 11 with a dry density of approximately 700 kg / m³, a designed drainage slope of 2%, and a molding thickness of 100 mm.

[0044] Raw materials and proportions, based on the preparation of 1 cubic meter of solid waste-based foamed gel lightweight slurry: Solid waste-based cementitious material dry powder: 300 kg; of which, Class I fly ash (F grade) 180 kg, accounting for 60% of the dry powder mass, and granulated blast furnace slag powder (S95 grade) 120 kg, accounting for 40%; Alkali activator solution: 135 kg; this solution was prepared 24 hours in advance and stirred evenly with 112 kg of industrial water glass (modulus 3.0), 8 kg of sodium hydroxide (purity 96%), and 15 kg of water. Its composite modulus was measured to be approximately 1.5. It contains approximately 18 kg of Na₂O, accounting for 6% of the mass of the gelling powder. Mixing water: 90 kg; Additives: 0.9 kg of polycarboxylate-based high-performance water-reducing agent (0.3% of dry powder), 0.45 kg of hydroxypropyl methylcellulose (HPMC) with a viscosity of 150,000 mPa·s (0.15% of dry powder), and 0.78 kg of 12 mm long polypropylene fiber (approximately 0.26% by volume). Foaming agent: A 5% mass concentration solution of a composite protein foaming agent is used to prepare approximately 7.5 cubic meters of pre-fabricated foam with a density of 50 kg / m³ using a physical foaming machine.

[0045] Construction process flow: Base treatment: Clean the reinforced concrete roof base 10 of the building to ensure it is flat, firm and free of standing water, and fully cover it with a 0.3mm thick polyethylene film as a vapor barrier 12, with an overlap width of not less than 100mm; Slurry preparation: First, put fly ash, slag powder, water reducing agent and HPMC into a forced mixer and dry mix for 1 minute. Then add alkali activator solution and mixing water, and stir at a speed of about 1500 r / min for 4 minutes to form a uniform slurry with a fluidity of about 200 mm. Add polypropylene fiber and stir at low speed for 2 minutes to disperse it evenly. Foaming and mixing: Slowly pour the pre-made foam into the slurry that is being stirred at low speed, and continue stirring for 2-3 minutes until the foam is evenly dispersed. The wet apparent density of the mixed slurry is measured to be approximately 1050 kg / m³. On-site casting: The solid waste-based foam cementitious lightweight slurry is pumped to the roof, and elevation control points are set according to the 2% drainage slope; after manual assisted spreading, it is leveled along the slope with a long screed and the surface is lightly compacted to control the forming thickness to 100mm. Curing: Immediately after smoothing, cover with plastic film for sealing and curing for 48 hours. Afterward, remove the film and water 2-3 times daily to keep the surface moist for 7 days. The ambient temperature during construction should be approximately 20-25℃. Performance test results, core sampling test conducted on-site after 28 days of standard maintenance; The formed lightweight functional layer 11 has a dry density of 720 kg / m³, a compressive strength of 4.2 MPa, a thermal conductivity of 0.15 W / (m·K), and a 24-hour volume water absorption rate of 12%, which meets the construction requirements. Then, a 4mm thick SBS modified bitumen waterproof membrane is laid as the waterproof layer 13 and a 20mm thick cement mortar is laid as the protective surface layer 14 to complete the roof construction.

[0046] Example 2: Construction of prefabricated lightweight roof by on-site assembly of precast components This example demonstrates the construction of a profiled steel roof for an industrial plant using a prefabricated component assembly method on-site.

[0047] Objective and Design: To produce prefabricated roof panels with a dry density of approximately 900 kg / m³, which will be assembled on-site to form a complete roof system.

[0048] Raw materials and proportions, based on the preparation of 1 cubic meter of solid waste-based foamed gel lightweight slurry: Solid waste-based cementitious material dry powder: 380 kg. Among them, Class F II fly ash 190 kg, accounting for 50% of the dry powder weight, and S95 grade granulated blast furnace slag powder 190 kg, accounting for 50%.

[0049] Alkali activator solution: 152 kg; prepared from 126 kg water glass, 9.5 kg sodium hydroxide, and 16.5 kg water, with a composite modulus of approximately 1.6; containing approximately 24.7 kg of Na₂O, accounting for 6.5% of the mass of the gelling dry powder; Mixing water: 76 kg; Additives: 1.14 kg of polycarboxylate superplasticizer (0.3% of dry powder), 0.76 kg of hydroxyethyl methyl cellulose (HEMC) with a viscosity of 180,000 mPa·s (0.2% of dry powder), and 1.14 kg of polyvinyl alcohol fiber with a length of 8 mm (approximately 0.3% by volume). Foaming agent: An animal protein foaming agent is used, which is prepared into a 6% mass concentration solution to prepare approximately 3.8 cubic meters of pre-fabricated foam with a density of 55 kg / m³.

[0050] Construction process flow: Precast slab production: Prepare slurry using a process similar to that in Example 1, controlling the final solid waste-based foam gel lightweight slurry wet density to be approximately 1180 kg / m³; inject the slurry into a 1200 mm × 600 mm × 80 mm shaped steel mold, gently vibrate to remove large air bubbles, smooth the surface, and then cover with a plastic film; Curing and demolding: The mold is placed in a steam curing chamber at 40℃ and left to cure for 20 hours, then demolded to obtain the precast slab; Post-construction maintenance: After demolding, the precast slabs are transferred to a standard curing room with a temperature of 20±2℃ and a relative humidity of >95% for continued curing for 6 days; On-site assembly: Asphalt-based vapor barrier membrane is laid on the roof base layer 10 of the profiled steel sheet as a vapor barrier layer 12; the precast panels that have been cured are transported to the roof site and laid in a staggered manner according to the design layout, with a 5mm wide joint left between the panels; the joints are filled and smoothed with micro-expansion repair mortar made of the same material as the precast panels. Performance test results, precast slab standard curing 28-day test: The precast slab has a dry density of 920 kg / m³, a compressive strength of 8.5 MPa, a thermal conductivity of 0.18 W / (m·K), and a water resistance rating of P8. These properties fully meet the requirements and satisfy the requirements for use on accessible roofs. System completion: On the assembled lightweight functional layer 11, a 1.5mm thick TPO polymer waterproof membrane is sequentially applied as the waterproof layer 13 and a 40mm thick C25 fine stone concrete is applied, with Φ4@150 steel wire mesh inside as the protective surface layer 14, thus completing the roof construction.

[0051] Compared to traditional solutions using cement perlite slope-finding layers and extruded polystyrene (XPS) insulation layers, this invention reduces the permanent roof load by approximately 30%-40% while achieving similar insulation performance. It also simplifies at least one construction step and avoids the aging and flammability issues associated with organic insulation materials, while significantly improving the utilization rate of solid waste resources. The lightweight roof and method based on solid waste-based cementitious materials provided by this invention creatively solves the industry problem of existing solid waste-based material technologies being unable to adapt to the multifunctional integrated needs of building roofs. It represents a significant advancement in technical concepts, functional integration, system adaptability, and overall benefits, providing an effective technical solution for the development of green, low-carbon, and high-performance buildings.

[0052] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lightweight roofing material based on solid waste cementitious materials, characterized in that, It includes a building roof base layer (10) and a lightweight functional layer (11) set on the building roof base layer (10). The lightweight functional layer (11) is a structural layer made of solid waste-based foam cementitious material with a dry density of 600-1000 kg / m³, a 28-day compressive strength of 3.0-10.0 MPa, and a thermal conductivity of 0.12-0.20 W / (m·K).

2. The lightweight roofing material based on solid waste cementitious materials according to claim 1, characterized in that, A vapor barrier (12) is provided between the building roof base layer (10) and the lightweight functional layer (11); a waterproof layer (13) and a protective surface layer (14) are sequentially provided above the lightweight functional layer (11).

3. A method for preparing a lightweight roof made of solid waste-based cementitious material, characterized in that, The method for preparing a lightweight roof made of solid waste-based cementitious material according to any one of claims 1 or 2 comprises the following steps: S1. Preparation of alkali-activated slurry: Mix and stir the dry powder of solid waste-based cementitious material with alkali activator solution and water to form a uniform alkali-activated slurry; Among them, the solid waste-based cementitious material dry powder contains fly ash and granulated blast furnace slag powder, and the alkali activator solution is a composite solution of water glass and sodium hydroxide with a modulus of 1.2-1.8; S2. Preparation of solid waste-based foamed gel lightweight slurry: The foaming agent solution is physically foamed to form pre-foam, and the pre-foam is introduced into the uniform alkali-activated slurry obtained in step S1. After uniform mixing, a solid waste-based foamed gel lightweight slurry with a wet apparent density of 800-1200 kg / m³ is obtained. S3. Constructing the roof functional layer: The solid waste-based foam cementitious lightweight slurry obtained in step S2 is used to construct a lightweight functional layer (11) with slope and thickness on the building roof base layer (10) by casting the solid waste-based foam cementitious lightweight slurry on site or by assembling prefabricated components on site. S4. Curing: Curing the lightweight functional layer (11) after molding.

4. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, The mass ratio of fly ash to granulated blast furnace slag powder in the dry powder of solid waste-based cementitious materials is (50%-70%): (30%-50%); the amount of alkali activator solution used is 4%-8% of the total mass of the dry powder of solid waste-based cementitious materials, calculated as Na2O.

5. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, In step S1, a polycarboxylate superplasticizer and a cellulose ether-based foam stabilizer are also added; the amount of polycarboxylate superplasticizer added is 0.2%-0.8% of the total mass of the dry powder of solid waste-based cementitious material, and the amount of cellulose ether-based foam stabilizer added is 0.1%-0.3% of the total mass of the dry powder of solid waste-based cementitious material.

6. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, In step S1, a synthetic fiber with a volume content of 0.1%-0.3% is also added. The synthetic fiber is either polypropylene fiber or polyvinyl alcohol fiber.

7. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, In step S2, the density of the pre-made foam is 40-60 kg / m³; in step S3, the molding thickness of the lightweight functional layer (11) is 50-200 mm, and the drainage slope formed on its surface is 1%-5%.

8. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, In step S3, on-site integral casting refers to directly pouring solid waste-based foam cement lightweight slurry onto the working surface of the building roof base (10), and after spreading, leveling and compacting, forming an integral seamless lightweight functional layer (11); on-site assembly of precast components refers to pouring solid waste-based foam cement lightweight slurry into a mold, curing and demolding to form precast components, and then laying the precast components on the building roof base (10) and forming a spliced ​​lightweight functional layer (11) after the board joints are treated.

9. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, In step S4, the curing includes: immediately covering and sealing the surface of the lightweight functional layer (11) before and after initial setting for 24-48 hours, followed by wet curing under the condition that the relative humidity of the environment is not less than 90%, and the wet curing time is not less than 7 days.

10. The method for preparing a lightweight roof made of solid waste-based cementitious material according to claim 3, characterized in that, The precast components are cured in the mold using steam at a temperature of 30-60℃ for 12-24 hours.

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