Thin building floor sound insulation system and construction method

Abstract

The invention provides a thin building floor sound insulation system and a construction method, and belongs to the technical field of light sound insulation building materials. The system sequentially comprises a base layer processing layer, an elastic cushion layer, a composite damping prefabricated plate layer, a polymer bonding layer, a light leveling layer and a facing layer from bottom to top. Wherein the composite damping prefabricated plate layer is provided with an internal material gradient structure, and the composite damping prefabricated plate layer is in continuous transition from a high-damping mixture area to a scattering enhanced mixture area from bottom to top; the polymer bonding layer is formed by flexible polymer modified cement mortar, and interlayer chemical bridging and mechanical occlusion are achieved in cooperation with self-activation treatment on the surface of the plate. Damping dissipation and sound wave scattering are synergistically achieved through the gradient structure, interlayer stress is buffered through the flexible bonding layer, efficient attenuation of wide-frequency-band impact sound is achieved under the conditions of extremely small thickness and low load, and the contradiction between space limitation and high sound insulation requirements in existing residence transformation is effectively solved.

Description

Technical Field

[0001] This invention belongs to the technical field of lightweight sound-insulating building materials, specifically relating to a thin floor sound insulation system and its construction method. Background Technology

[0002] In modern residential buildings, floor sound insulation performance is a crucial indicator of living quality. Existing high-performance sound insulation leveling systems generally follow the mass law and the double-layer vibration isolation theory, relying on increasing the surface density and thickness of the floor slab to achieve higher sound insulation. For example, traditional concrete-based floating systems typically require a thick layer of fine aggregate concrete or gypsum-based self-leveling compound as the upper mass block, often resulting in a total system thickness of 80 to 120 mm, accompanied by a significant increase in surface load. While this approach of increasing thickness and weight can meet acoustic standards, it often leads to problems such as insufficient interior height, exceeding the original structural load limits, and excessively long construction periods in existing building renovations or new construction projects with limited floor height.

[0003] To adapt to scenarios with limited space and load, existing technologies have attempted to employ thin composite systems, such as using thin-layer elastic pads combined with prefabricated panels like fiber cement boards, supplemented by thin-layer leveling materials. However, such systems have revealed significant performance limitations in practical applications: Firstly, limited by the total thickness, simply thinning uniform material components makes it difficult to provide sufficient low-frequency vibration isolation efficiency and sound energy dissipation capacity, resulting in unsatisfactory isolation of low-frequency impact sounds such as footsteps; secondly, due to the difference in material properties (such as elastic modulus and drying shrinkage rate) between the prefabricated panel layer and the upper leveling layer, this rigidly stacked structure is prone to developing micro-cracks, hollow areas, or even peeling at the interlayer interface under long-term use or temperature and humidity changes. This not only damages the structural integrity of the floor but also creates sound bridges due to poor interfacial contact, further degrading sound insulation performance.

[0004] Therefore, how to achieve excellent broadband impact sound insulation while ensuring the long-term bonding stability of the internal structural layers of the system under the premise of strictly limiting the total thickness and surface load of the system is a major common technical challenge currently faced in the field of floor sound insulation technology. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a thin floor sound insulation system and construction method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a thin floor sound insulation system, comprising, from bottom to top, a base treatment layer, an elastic pad layer, a composite damping precast panel layer, a polymer bonding layer, a lightweight leveling layer, and a finishing layer;

[0007] The base treatment layer is formed by a cement-based interface treatment agent that is cured on the surface of the floor base layer;

[0008] The elastic underlayment is laid on top of the base treatment layer;

[0009] The composite damping precast panel layer is set on top of the elastic pad layer and is spliced ​​together from composite damping precast panels;

[0010] The polymer bonding layer is placed between the composite damping precast slab layer and the lightweight leveling layer, and is formed by curing flexible polymer modified cement mortar.

[0011] The lightweight leveling layer is placed on top of the polymer bonding layer and is formed by the curing of gypsum-based self-leveling mortar.

[0012] Preferably, the total thickness of the composite damping precast panel is 10 to 15 mm, and it includes a bottom layer, a core layer and a top layer from bottom to top;

[0013] The lower layer includes cement as a hydraulic cementitious material, waste rubber particles as an elastic damping component, redispersible latex powder as a film-forming binder component, and damping board additives.

[0014] The core layer exhibits a continuous, gradual transition from the high-damping mixture region near the lower layer to the scattering-enhancing mixture region near the upper layer.

[0015] The top layer is composed of a cement-based material whose surface has been mechanically roughened and coated with a silane interface activator.

[0016] Preferably, the core layer is composed of a high-damping mixture and a scattering-enhancing mixture, both of which include waste rubber particles and closed-cell vitrified microspheres.

[0017] Preferably, in the high-damping mixture, waste rubber particles account for 30 to 50% of the total aggregate volume, and closed-cell vitrified microspheres account for 5 to 20% of the total aggregate volume.

[0018] Preferably, closed-cell vitrified microspheres account for 20 to 30% of the total aggregate volume in the scattering-enhanced mixture, and waste rubber particles account for 10 to 20% of the total aggregate volume.

[0019] Preferably, the silane interface activator is γ-aminopropyltriethoxysilane; the damping plate additive includes polypropylene fiber and hydroxypropyl methylcellulose ether.

[0020] Preferably, the polymer adhesive layer is formed of flexible polymer-modified cement mortar.

[0021] 6. A thin floor sound insulation system according to claim 1, characterized in that the elastic pad layer is a polyurethane sound insulation pad.

[0022] 7. A thin floor sound insulation system according to claim 1, characterized in that the surface layer is wood flooring or polyvinyl chloride roll material.

[0023] Another technical solution provided by the present invention: a construction method based on the above-mentioned thin floor sound insulation system, comprising the following steps:

[0024] M1: Clean and treat the base layer of the floor and surface, and lay polyurethane sound insulation pads to form a base treatment layer and an elastic pad layer.

[0025] M2: The composite damping precast panels are dry-laid on top of the elastic pad layer by tongue and groove splicing to form a composite damping precast panel layer;

[0026] M3: Apply flexible polymer-modified cement mortar to the surface of the composite damping precast panel layer to form a polymer bonding layer;

[0027] M4: Pour gypsum-based self-leveling mortar onto the surface of the polymer bonding layer to form a lightweight leveling layer;

[0028] M5: Curing the lightweight leveling layer and laying finishing materials on the surface of the lightweight leveling layer.

[0029] Preferably, the composite damping precast plate in step M2 is prepared through the following steps:

[0030] S1: Prepare the lower layer slurry, high-damping mixture, scattering-enhancing mixture and upper layer slurry;

[0031] S2: The lower layer slurry is laid on the bottom of the molding die. The high-damping mixture and the scattering-enhancing mixture are simultaneously laid on the upper layer slurry through a separation material laying process to obtain the combined initial blank.

[0032] S3: Apply mechanical vibration and static pressure to the combined billet to obtain a semi-finished sheet metal body with tongue and groove structure;

[0033] S4: Spray an interface agent onto the surface of the core layer of the semi-finished board and pour the top layer slurry to obtain a complete wet board blank.

[0034] S5: Curing the wet blank of the complete board to obtain a cured board;

[0035] S6: The surface of the upper layer of the cured board is mechanically roughened and chemically activated to obtain a composite damping precast board.

[0036] Preferably, in step S6, the mechanical roughening depth is controlled to be between 0.5 and 1.0 mm, and the chemical activation treatment is spraying a γ-aminopropyltriethoxysilane solution.

[0037] This invention overcomes the technical bottleneck of existing technologies that rely on increasing thickness and mass for high-performance sound insulation by reconstructing the internal material distribution and interface connection mechanism of the sound insulation layer. While meeting the strict limitations on thickness and load for existing residential renovations, it achieves a significant improvement in the sound insulation performance of floor impact noise, specifically possessing the following beneficial effects:

[0038] The composite damping precast panel layer adopts a material gradient distribution structure with a continuous vertical transition, gradually changing from the high-damping mixture region to the scattering-enhancing mixture region from bottom to top. Utilizing the intramolecular friction of the polymer chains in the waste rubber particles of the high-damping mixture, the transmitted sound wave vibration energy is converted into heat energy dissipation. Simultaneously, the porous interface characteristics of the closed-cell vitrified microspheres in the scattering-enhancing mixture force the sound wave to undergo multiple reflections and scatterings along its propagation path. Through this microscopic synergistic mechanism of damping dissipation and sound wave scattering, the composite damping precast panel layer effectively widens the sound insulation band within a limited thickness space, particularly enhancing the attenuation capability of low-frequency vibration energy. Compared to existing technologies that rely on a single homogeneous material or simply stacked mass of precast panels, the composite damping precast panel layer significantly improves the isolation efficiency for broadband impact sound without significantly increasing the total system thickness and areal density.

[0039] The polymer adhesive layer is formed by applying flexible polymer-modified cement mortar and is treated with a silane-based interface activator on top of the composite damping precast panel layer. This establishes a tight interfacial bond between the composite damping precast panel layer and the lightweight leveling layer based on chemical bridging and mechanical interlocking. The polymer adhesive layer penetrates into the micropores of the top layer, while the chemical bonding force generated by the silane-based interface activator enhances the interlayer bond strength. Furthermore, the polymer adhesive layer, with its inherent flexibility, creates an elastic modulus transition zone between the rigid composite damping precast panel layer and the lightweight leveling layer, effectively buffering interfacial shear stress caused by vibration transmission or changes in environmental temperature and humidity. Compared to the rigid cement bonding or loose physical contact commonly used in existing technologies, the polymer adhesive layer effectively prevents micro-cracks, hollow areas, or peeling at the interlayer interface, thereby eliminating sound bridging effects and sound energy leakage caused by structural defects and ensuring the long-term stability of the system's sound insulation performance.

[0040] The gradient attenuation characteristics of the composite damping precast panel layer interact with the flexible coupling characteristics of the polymer adhesive layer, optimizing the overall performance of the thin floor sound insulation system. The polymer adhesive layer ensures that sound energy can be continuously and uniformly introduced into the interior of the composite damping precast panel layer, allowing the gradient structure of the composite damping precast panel layer to fully exert its sound energy dissipation effect; at the same time, the composite damping precast panel layer provides stable mechanical support for the superstructure. This deep integration of structure and function enables the thin floor sound insulation system to control the total thickness and additional load within a very low range, while achieving high-standard weighted standardized impact sound pressure level indicators. This effectively solves the contradiction between limited space height and high sound insulation requirements in the renovation of existing buildings, improving the system's environmental adaptability and construction feasibility. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a structural diagram of a thin floor sound insulation system;

[0043] Figure 2 This is a flowchart illustrating the preparation method of composite damping prefabricated panels in a thin floor sound insulation system.

[0044] Figure 3 This is a flowchart illustrating the construction method of a thin floor sound insulation system. Detailed Implementation

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0046] Unless otherwise specified, all raw materials described below may be commercially available or prepared using conventional methods in the art.

[0047] Application Overview:

[0048] This invention reveals that the fundamental reason for the inadequacy of existing thin sound insulation systems lies in the fact that a single homogeneous material cannot form an effective sound energy dissipation and scattering mechanism within a limited thickness, and the rigid connections between layers cannot buffer the interfacial stress generated by material deformation. Based on this, this invention achieves highly efficient attenuation of broadband (especially low-frequency) impact sound under the constraints of extremely low total system thickness and minimal additional load, meeting high standards of sound insulation. Simultaneously, in a multi-layered composite thin structure, it solves the problem of interfacial cracking and bonding failure caused by the mismatch in elastic modulus and shrinkage characteristics between the precast component layer and the cast-in-place leveling layer, eliminating the risk of sound bridges and ensuring the structural durability of the system.

[0049] A thin floor sound insulation system is used in the sound insulation renovation of existing residential buildings, and is also suitable for the sound insulation construction of newly built residential buildings with strict limitations on space height and load. For example... Figure 1 As shown, the system consists of a base treatment layer, an elastic pad layer, a composite damping precast panel layer, a polymer bonding layer, a lightweight leveling layer, and a finishing layer, from bottom to top. Each structural layer is continuously stacked in the vertical direction to form an integral structure.

[0050] The base treatment layer is located between the floor base and the elastic cushion layer. It is cured with a cement-based interface treatment agent to form an interface suitable for laying the elastic cushion layer. The elastic cushion layer is fully laid on top of the base treatment layer and absorbs vibration energy through its own elastic deformation and damping dissipation. The composite damping precast panel layer is set on top of the elastic cushion layer and achieves broadband sound energy attenuation through material gradient distribution. The polymer bonding layer is located between the composite damping precast panel layer and the lightweight leveling layer to achieve the interface bonding of the two layers. The lightweight leveling layer is laid on top of the polymer bonding layer to form a flat surface for the finishing layer to be laid. The finishing layer covers the surface of the lightweight leveling layer, forming the final usable surface of the floor, receiving the sound energy from the upper part and transmitting it to the lower structure.

[0051] The functional coupling relationship and energy transfer path between each structural layer are adapted to the sound transmission direction. The sound transmission path is from top to bottom, that is, from the finishing layer to the lightweight leveling layer, polymer bonding layer, composite damping precast panel layer, elastic pad layer, base treatment layer, and finally to the floor base layer.

[0052] Sound energy, as the transmitted energy, gradually attenuates during transmission through the synergistic effect of each structural layer. This gradual attenuation constitutes the functional coupling relationship between the structural layers. Specifically, the energy transmission process is as follows: the finishing layer receives the sound energy from above and transmits it to the lightweight leveling layer; the lightweight leveling layer, through its flat structure, evenly distributes and transmits the sound energy to the polymer bonding layer, ensuring uniform distribution during transmission; the polymer bonding layer, while achieving interfacial bonding between the composite damping precast panel layer and the lightweight leveling layer, allows sound energy to penetrate and be transmitted to the composite damping precast panel layer, and its flexible properties buffer vibrations generated during sound energy transmission, preventing vibrations from altering the interfacial bonding between the composite damping precast panel layer and the lightweight leveling layer. The composite damping precast panel layer primarily attenuates the transmitted sound energy through its own material gradient structure. Sound energy is reduced within the composite damping precast panel layer through damping dissipation and scattering. The remaining sound energy after attenuation by the composite damping precast panel layer is transferred to the elastic pad layer. The elastic pad layer further absorbs the vibrational components of the sound energy through its own elastic deformation, reducing the sound energy transmission efficiency. The residual sound energy is finally transferred to the floor base layer through the base treatment layer. The base treatment layer reduces sound energy reflection and secondary transmission at the interface through optimized interface morphology, completing the full-path attenuation of sound energy. Effective energy transfer is achieved through tight interfacial bonding between the various structural layers. Simultaneously, the matching of material properties of each structural layer ensures continuous attenuation of sound energy during transmission, avoiding sound energy reflection or localized accumulation caused by poor interlayer bonding or material mismatch.

[0053] Based on the design principles of structural layers, the following provides a detailed explanation of the thin floor sound insulation system.

[0054] For example, the base treatment layer is the bottommost structural layer in a thin floor sound insulation system, located between the floor base layer and the elastic cushion layer, and is formed by a cement-based interface treatment agent coated on the surface of the floor base layer through a curing process. The base treatment layer has a thickness of 1 to 5 mm and includes cement, aggregate, polymer modifier, and rheology modifier. The cement is P·O42.5 grade ordinary Portland cement, which participates in the hydration reaction to form a hardened structure and provides mechanical strength to the base treatment layer; the aggregate is quartz sand with a particle size of 0.1 to 0.5 mm, which fills the internal voids of the base treatment layer and increases the hardness of the film layer; the polymer modifier is a redispersible latex powder with film-forming and adhesion-enhancing properties, specifically an ethylene-vinyl acetate copolymer; the rheology modifier includes a thickening and water-retaining agent and a defoamer, wherein the thickening and water-retaining agent is hydroxypropyl methylcellulose ether, and the defoamer is polydimethylsiloxane.

[0055] After the cement-based interface treatment agent is applied to the floor substrate, the cement inside undergoes a hydration reaction with water, generating hydrated calcium silicate gel and calcium hydroxide crystals. These hydration products penetrate into the capillary channels on the surface of the floor substrate with the water, precipitating inside the channels and forming a micro-anchoring structure. Accompanying the water migration during the curing process, ethylene-vinyl acetate copolymer particles accumulate on the surface of the cement hydration products and at the micro-protrusions of the floor substrate, coalescing into a continuous polymer film as the water evaporates.

[0056] Based on the hydration anchoring of cement and the film-forming mechanism of polymer modifiers in cement-based interface treatment agents, the base treatment layer establishes a composite interface of physical interlocking and chemical bonding on the surface of the floor substrate, filling the open pores on the surface of the floor substrate, changing the surface physical morphology of the original substrate, and improving the surface bonding strength of the floor substrate. When sound energy is transmitted from top to bottom from the finishing layer to the elastic pad layer and further diffuses into the floor substrate, the base treatment layer uses a continuously distributed membrane structure to block the path of sound energy transmission through pores; at the same time, the membrane layer formed by the curing of the base treatment layer provides a horizontal support interface for the elastic pad layer, so that the compressive deformation of the elastic pad layer is evenly distributed along the entire paving surface.

[0057] For example, the elastic pad layer is a structural layer in a thin floor sound insulation system, positioned above the base treatment layer and below the composite damping precast panel layer, formed by a polyurethane sound insulation pad fully covering the surface of the base treatment layer. The polyurethane sound insulation pad is 3 to 5 mm thick and includes a polyurethane polymer material as the continuous phase matrix and closed-cell bubbles distributed within the polyurethane polymer material as the dispersed phase. The polyurethane polymer material is formed by the polymerization reaction of polyisocyanate and combined polyether; the closed-cell bubbles are formed by the gas generated by the foaming agent during the polymerization reaction being encapsulated by the polyurethane polymer material, forming independent cavities within the polyurethane sound insulation pad, i.e., a closed-cell structure.

[0058] When the composite damping precast panel layer transmits acoustic energy carrying mechanical vibrations downwards, the acoustic energy acts on the upper surface of the elastic pad layer. The closed-cell structure inside the polyurethane sound insulation pad undergoes compressive elastic deformation under sound wave pressure, absorbing and storing the kinetic energy of the acoustic energy. During construction, the polyurethane sound insulation pad achieves a tight bond with the base treatment layer, and the vibrations generated by the acoustic energy are evenly distributed across the entire pressure-bearing surface of the polyurethane sound insulation pad. After absorbing vibrational energy, the polyurethane molecular chains undergo relative displacement, converting the vibrational energy into heat energy through intermolecular internal friction and dissipating it into the surrounding environment, thus achieving attenuation of the acoustic energy within the elastic pad layer.

[0059] For example, the composite damping precast panel layer is a structural layer in a thin floor sound insulation system, positioned above the elastic pad layer and below the polymer adhesive layer. It is formed by interlocking and dry-laying composite damping precast panels using a tongue-and-groove structure. The total thickness of the composite damping precast panel layer is 10 to 15 mm. The composite damping precast panels have non-uniformly distributed material properties in the vertical direction, and are composed of three functional areas—a lower layer, a core layer, and a top layer—that transition continuously from bottom to top.

[0060] The bottom layer of the composite damping precast slab has a thickness of 1 to 3 mm and includes cement as a hydraulic cementitious material, waste rubber particles as an elastic damping component, redispersible latex powder as a film-forming binder, and damping slab additives. The redispersible latex powder is the same substance as the ethylene-vinyl acetate copolymer used in the base treatment layer; the damping slab additives include polypropylene fibers and hydroxypropyl methylcellulose ether. The polypropylene fibers act as a crack-resistant component, inhibiting crack formation during the molding and service of the bottom layer and maintaining its structural integrity; the hydroxypropyl methylcellulose ether is the same substance as the base treatment layer and acts as a water-retaining component, maintaining the moisture stability of the bottom layer material system and ensuring sufficient cement hydration.

[0061] The core layer of the composite damping precast slab has a thickness of 8 to 11 mm, exhibiting a continuous, gradual transition from the high-damping mixture region near the lower layer to the scattering-enhancing mixture region near the upper layer. In the high-damping mixture, waste rubber particles account for 30 to 50% of the total aggregate volume, and closed-cell vitrified microspheres account for 5 to 20%; in the scattering-enhancing mixture, closed-cell vitrified microspheres account for 20 to 30% of the total aggregate volume, and waste rubber particles account for 10 to 20%. The upper layer has a thickness of 1 to 3 mm and consists of a cement-based material layer with a mechanically roughened surface coated with a silane-based interfacial activator, specifically γ-aminopropyltriethoxysilane.

[0062] As acoustic energy is transmitted downwards from the polymer adhesive layer to the composite damping precast panel layer, the mechanically roughened interface of the upper layer and γ-aminopropyltriethoxysilane enhance the chemical bonding and micro-mechanical interlocking forces between the composite damping precast panel and the polymer adhesive layer through chemical bridging. Acoustic energy first enters the upper layer and penetrates into the core layer. Inside the core layer, sound waves sequentially pass through regions dominated by scattering-enhancing compounds and regions dominated by high-damping compounds. Closed-cell vitrified microspheres in the scattering-enhancing compounds utilize porous particle interfaces to cause multiple reflections and scattering of sound waves, altering the direction of sound propagation and extending the propagation path. Waste rubber particles in the high-damping compounds utilize the internal friction of polymer chain segments to convert vibrational energy in the acoustic energy into heat dissipation. The lower layer, through a high-density inorganic matrix and the waste rubber particles distributed within it, further dampens and absorbs the residual low-frequency vibration components that have penetrated the core layer.

[0063] The functional gradient transition within the composite damping precast panel layer ensures a continuous change in acoustic impedance along the thickness direction, reducing the superposition of acoustic energy reflections caused by abrupt changes in material properties. The interface modification treatment of the upper layer eliminates the air gap between the composite damping precast panel and the polymer adhesive layer, preventing acoustic energy diffraction at the interlayer boundaries. The zoned collaborative working mechanism of the core layer enables the composite damping precast panel layer to attenuate a wide range of acoustic energy within a thickness constraint of 10 to 15 mm. The high damping characteristics of the lower layer specifically reduce low-frequency impact sound pressure levels, compensating for the isolation capability of a single elastic material for low-frequency acoustic energy. The overall stiffness of the composite damping precast panel layer provides a load-bearing base for the upper lightweight leveling layer, ensuring the structural stability of the overall system and allowing acoustic energy to transfer to the elastic pad layer along a gradient attenuation path during transmission.

[0064] For example, the polymer bonding layer is a structural layer in a thin floor sound insulation system, positioned above the composite damping precast slab layer and below the lightweight leveling layer. The polymer bonding layer is formed by applying a flexible polymer-modified cement mortar to the upper surface of the composite damping precast slab layer, with a thickness of 1 to 5 mm. The polymer bonding layer includes cement-based cementitious materials, fine aggregates, polymer-modifying components, and mortar functional additives. The cement-based cementitious material is P·O42.5 grade ordinary Portland cement; the fine aggregate is quartz sand with a particle size distribution of 0.1 to 0.3 mm; the polymer-modifying component is an acrylic emulsion with a solid content distribution of 30% to 70%; the mortar functional additives include a water-reducing component and an air-entraining component, the water-reducing component being a polycarboxylate-based high-efficiency water-reducing agent, and the air-entraining component being a rosin thermal polymer.

[0065] During the application of flexible polymer-modified cement mortar to the top layer of the composite damping precast slab, it penetrates the roughened interface formed by mechanical roughening of the top layer. The crystalline structure produced by cement hydration physically intercalates with the acrylic emulsion particles within the micropores of the top layer, while simultaneously reacting chemically with the γ-aminopropyltriethoxysilane coated on the surface of the top layer to form a chemically bridged structure. The combined effect of chemical bridging and mechanical interlocking establishes a tight interfacial bond between the polymer adhesive layer and the composite damping precast slab layer. After the polymer adhesive layer cures, the bonding properties formed on the upper surface provide a suitable interface for the laying of the lightweight leveling layer, which is physically bonded to the lightweight leveling layer through the intermolecular forces of the flexible polymer-modified cement mortar itself.

[0066] When acoustic energy is transmitted downwards from the lightweight leveling layer to the polymer bonding layer, the polymer bonding layer allows sound waves to penetrate and conduct to the composite damping precast slab layer through its continuous internal material distribution. The elastic modulus of the flexible polymer-modified cement mortar is lower than that of the upper layer and the lightweight leveling layer, forming a modulus gradient transition structure within the system. When acoustically excited mechanical vibrations pass through, the polymer bonding layer utilizes its flexibility to buffer the vibration displacement, converting some of the mechanical vibration energy into heat energy, thus preventing the vibration from directly acting on the composite damping precast slab layer and causing stress concentration at the interface. The modulus gradient structure absorbs the deformation and strain difference between the lightweight leveling layer and the composite damping precast slab layer caused by changes in ambient temperature and humidity, maintaining the interfacial bonding state.

[0067] The polymer bonding layer reduces the interlayer gap at the interface between the composite damping precast panel layer and the lightweight leveling layer by establishing chemical bridging and mechanical interlocking, thus blocking the reflection and diffraction of sound waves at the gaps. The uniformly distributed flexible polymer-modified cement mortar ensures the energy distribution of sound waves during transmission, preventing interface separation caused by localized vibration energy accumulation. By achieving gradient adjustment of the material modulus, the polymer bonding layer reduces the internal stress generated by interlayer deformation within the system, ensuring that the composite damping precast panel layer stably receives the sound energy transmitted from the superstructure, allowing the sound energy attenuation process to continue.

[0068] For example, the lightweight leveling layer is a structural layer in a thin floor sound insulation system, positioned above the polymer bonding layer and below the finishing layer. The lightweight leveling layer is formed by curing gypsum-based self-leveling mortar poured onto the surface of the polymer bonding layer, with a thickness of 8 to 15 mm. The gypsum-based self-leveling mortar includes hemihydrate gypsum as a cementing material, quartz sand as a filler component, water, and gypsum-based functional additives, including water-reducing agents and retarders. Hemihydrate gypsum undergoes a hydration reaction upon contact with water, generating dihydrate gypsum crystals, providing structural strength to the lightweight leveling layer; the water-reducing agent adjusts the rheological properties of the gypsum-based self-leveling mortar, ensuring the mortar has self-leveling capabilities; the retarder is citric acid, which extends the initial setting time of the gypsum-based self-leveling mortar, ensuring surface smoothness control during construction.

[0069] After the gypsum-based self-leveling mortar is poured onto the surface of the polymer bonding layer, it automatically spreads on the surface of the polymer bonding layer by gravity, filling the micro-undulations on the surface of the polymer bonding layer and forming a horizontal geometric plane.

[0070] As acoustic energy is transferred downwards from the finishing layer to the lightweight leveling layer, the lightweight leveling layer utilizes its continuous and uniformly distributed internal crystalline network structure to diffuse the mechanical vibrations excited by the acoustic energy horizontally, achieving a uniform distribution of acoustic energy across the entire structural plane. When sound waves pass through the porous structure within the lightweight leveling layer, multiple reflections and scattering occur at the pore walls, causing the propagation direction of the sound waves to deflect and increasing the propagation path length. The lightweight leveling layer then uniformly transfers the scattered acoustic energy to the underlying polymer bonding layer. Based on the density characteristics of gypsum-based materials, the lightweight leveling layer reduces mass accumulation while meeting structural strength requirements.

[0071] For example, the finishing layer is the uppermost structural layer in a thin floor sound insulation system, placed above the lightweight leveling layer and directly facing the building's interior space. The finishing layer is wood flooring or PVC rolls; the wood flooring is 8 to 12 mm thick engineered wood flooring or laminate flooring; the PVC rolls are 2 to 4 mm thick dense PVC flooring rolls.

[0072] The sound energy generated by the upper environment acts directly on the upper surface of the finishing layer. Through a tight fit with the lightweight leveling layer, the finishing layer transmits the received sound energy evenly downwards in the vertical direction. The wood flooring or PVC roll material possesses a certain material density and surface hardness. When subjected to mechanical impact or friction, the material structure of the finishing layer directly interacts with external objects, absorbing and resisting external loads using its own wear-resistant physical properties. The interface between the finishing layer and the underlying layer eliminates macroscopic air gaps through the installation process, maintaining the continuity of sound energy propagation across the interface between the finishing layer and the lightweight leveling layer.

[0073] The thickness of the finish layer is selected to match the thinness of the thin floor sound insulation system, providing a functional interface without significantly increasing the overall system thickness. The finish layer features a dense and easy-to-clean surface structure, reducing maintenance difficulties during use.

[0074] like Figure 2 As shown, a method for preparing a composite damping precast panel includes the following steps:

[0075] S1: Prepare the lower layer slurry, high-damping mixture, scattering-enhancing mixture and upper layer slurry;

[0076] S2: The lower layer slurry is laid on the bottom of the molding die. The high-damping mixture and the scattering-enhancing mixture are simultaneously laid on the upper layer slurry through a separation material laying process to obtain the combined initial blank.

[0077] S3: Apply mechanical vibration and static pressure to the combined blank in the forming mold to obtain a semi-finished sheet body with tongue and groove structure;

[0078] S4: Spray an interface agent onto the surface of the core layer of the semi-finished board and pour the top layer slurry to obtain a complete wet board blank.

[0079] S5: Curing the wet blank of the complete board to obtain a cured board;

[0080] S6: The surface of the upper layer of the cured board is mechanically roughened and chemically activated to obtain a composite damping precast board.

[0081] The following provides a detailed explanation of each step in the preparation method.

[0082] In step S1, the raw materials for the lower layer slurry include P·O42.5 grade ordinary Portland cement, waste rubber granules, redispersible latex powder, water, and damping board additives. The redispersible latex powder is an ethylene-vinyl acetate copolymer; the damping board additives are composed of polypropylene fibers and hydroxypropyl methylcellulose ether. The above raw materials are mixed and stirred until a uniform rheological state is reached.

[0083] The raw materials for the high-damping mixture include waste rubber particles, closed-cell vitrified microspheres, P·O42.5 grade ordinary Portland cement, redispersible latex powder, and water. In the total aggregate volume of the high-damping mixture, waste rubber particles account for 30% to 50% of the volume, and closed-cell vitrified microspheres account for 5% to 20%.

[0084] The raw materials for the scattering-reinforced aggregate include closed-cell vitrified microspheres, waste rubber particles, P·O42.5 grade ordinary Portland cement, redispersible latex powder, and water. In the total aggregate volume of the scattering-reinforced aggregate, the closed-cell vitrified microspheres account for 20% to 30% of the volume, and the waste rubber particles account for 10% to 20%.

[0085] The raw materials for the top layer slurry include: P·O42.5 grade ordinary Portland cement, quartz sand, and water. The above raw materials are mixed and stirred until a uniform rheological state is reached.

[0086] In the above raw materials, the moisture content of the high-damping mixture and the scattering-enhancing mixture is controlled at 8 to 12%; the amount of redispersible latex powder added is 0.5 to 1.0% of the weight of the cementitious material; and the stirring time is 3 to 5 minutes.

[0087] In step S2, the lower layer of slurry is evenly spread on the bottom of the molding mold, whose inner wall is coated with an organosilicon release agent, to a thickness of 1 to 3 mm. A movable dividing material distribution device is installed inside the molding mold cavity to divide the core layer area of ​​the board into two horizontal zones. The high-damping mixture and the scattering-enhancing mixture are filled into the corresponding zones of the cavity, respectively, with the material distribution speed controlled at 0.5 to 1.0 m / s. 3 / h to ensure synchronous filling. After filling, slowly remove the separating fabric device to allow the high-damping mixture and the scattering-enhancing mixture to come into natural contact at the interface. The fabric thickness should be adjusted according to the compaction coefficient to ensure the core layer thickness of the pressed board is 8 to 11 mm.

[0088] In step S3, the forming mold containing the assembled blank is placed on a vibration table, and mechanical vibration with a frequency of 25Hz to 50Hz and an amplitude of 0.5 to 1.0mm is applied for a duration of 30 to 60 seconds. After vibration, a static pressure of 0.5 to 1.0MPa is applied to the upper surface of the assembled blank through a hydraulic press die head, and the pressure is held for 5 to 10 minutes. Utilizing the convex and concave structure of the forming mold edge, a tongue and groove structure is synchronously formed under static pressure to obtain the main body of the sheet metal semi-finished product.

[0089] In step S4, an acrylic emulsion interface agent (solid content 45% to 55%) is uniformly sprayed onto the core layer of the semi-finished board using a high-pressure spraying device at a spraying rate of 0.2 to 0.3 kg / m². 2 Before the acrylic emulsion interface agent dries (within 5 to 10 minutes), pour the top layer slurry on top of the core layer, smooth it with a scraper, and control the thickness of the top layer to 1 to 3 mm to obtain a complete wet board blank.

[0090] In step S5, the complete wet sheet material, along with the molding die, is placed in a curing environment for curing. For standard curing: ambient temperature 20℃±2℃, relative humidity greater than 95%, curing period 28 days. For autoclaving: placed in an autoclave, pressure 0.8 to 1.2 MPa, temperature 174 to 187℃, constant temperature and pressure curing for 12 hours; after cooling and demolding, continue curing in a normal temperature and high humidity environment for 3 days. After curing, a cured sheet material is obtained.

[0091] In step S6, a shot blasting machine is used to mechanically roughen the surface of the upper layer of the cured board. The shot blasting material is steel shot with a particle size of 0.5 to 1.0 mm, and the shot blasting pressure is 0.3 to 0.5 MPa. After mechanical roughening, surface dust and loose particles are removed. A silane interface activator solution is uniformly sprayed using a low-pressure spraying device. The silane interface activator solution is prepared by diluting γ-aminopropyltriethoxysilane and ethanol at a volume ratio of 1:10, and the spraying amount is 0.1 to 0.2 kg / m³. 2 The boards are placed in a drying oven at 50 to 80°C for drying and curing, with a drying time of 2 to 4 hours. The mechanical roughening depth is controlled between 0.5 and 1.0 mm.

[0092] During mechanical roughening, high-speed steel shot impacts the surface of the cured board, removing surface laitance and loose particles, exposing the hard aggregate and cement stone structure inside, significantly increasing the specific surface area and micro-roughness of the surface layer. After spraying with a silane interface activator solution, γ-aminopropyltriethoxysilane molecules undergo hydrolysis and condensation reactions on the board surface, generating silanol groups. These silanol groups react with the hydroxyl groups on the cement stone surface to form chemical bonds, anchoring the inorganic-philic groups to the cement substrate while exposing active functional groups such as amino groups. This surface modification alters the surface energy and chemical activity of the board surface, enhancing its reactivity with polymer bonding materials.

[0093] like Figure 3 As shown, a construction method for a thin floor sound insulation system includes the following steps:

[0094] M1: Clean and treat the base layer of the floor and surface, and lay polyurethane sound insulation pads to form a base treatment layer and an elastic pad layer.

[0095] M2: The composite damping precast panels are dry-laid on top of the elastic pad layer by tongue and groove splicing to form a composite damping precast panel layer;

[0096] M3: Apply flexible polymer-modified cement mortar to the surface of the composite damping precast panel layer to form a polymer bonding layer;

[0097] M4: Pour gypsum-based self-leveling mortar onto the surface of the polymer bonding layer to form a lightweight leveling layer;

[0098] M5: Curing the lightweight leveling layer and laying finishing materials on the surface of the lightweight leveling layer.

[0099] The following provides a detailed explanation of each step in the preparation method.

[0100] In step M1, the surface of the floor substrate is cleaned, mechanically ground, and dusted to ensure that there is no laitance, oil, or loose impurities. The cement-based interface treatment agent (water-to-material ratio 0.25 to 0.30) is applied at a rate of 0.3 to 0.5 kg / m². 2 The coating is evenly applied to the base surface and allowed to dry and cure to form a base treatment layer. A polyurethane sound insulation pad is then fully laid on top of the base treatment layer to form an elastic padding layer. During installation, the edge of the polyurethane sound insulation pad extends upwards 10 to 50 mm along the base of the wall. Adjacent joints are sealed with butyl rubber tape, and the joint width should not exceed 2 mm.

[0101] In step M2, the composite damping precast panels are horizontally interlocked using the tongue-and-groove structure on the sides and dry-laid on top of the elastic pad layer to form a composite damping precast panel layer. During splicing, ensure that the tongue and groove are fully engaged, and leave an 8 to 12 mm expansion gap between the edge of the composite damping precast panel and the wall, without using rigid adhesive for fixing.

[0102] In step M3, prepare flexible polymer-modified cement mortar (water-to-material ratio 0.35 to 0.40) and stir until homogeneous and lump-free. Pour the flexible polymer-modified cement mortar onto the surface of the composite damping precast panel layer and use a notched scraper to evenly spread it in the same direction, controlling the coating thickness to be 1 to 5 mm, forming a polymer bonding layer. During the spreading process, ensure complete coverage of the panel joints and surface texture, and compact the joints.

[0103] In step M4, while the polymer bonding layer is in its initial setting state (1 to 2 hours after application), prepare a gypsum-based self-leveling mortar (water-to-material ratio 0.30 to 0.35) and stir it until the fluidity is 180 to 200 mm. Pour or pump the gypsum-based self-leveling mortar onto the surface of the polymer bonding layer, allowing it to level naturally using its fluidity. Use an air-exploding roller to remove air bubbles, forming a lightweight leveling layer with a thickness of 8 to 15 mm.

[0104] In step M5, after the lightweight leveling layer is poured, the site is sealed off for natural curing (ambient temperature 15 to 25℃, relative humidity ≥70%), with a curing time of no less than 24 hours. After curing, a finishing layer is laid on the surface of the lightweight leveling layer. If it is wood flooring, it is laid using a click-lock system; if it is PVC roll material, it is fixed with adhesive and the joints are sealed.

[0105] Example 1:

[0106] This embodiment provides a thin floor sound insulation system for making acoustic performance test samples. The specific steps are as follows:

[0107] M1: A thickness of 120mm and an area of ​​10m² 2 The surface of a standard reinforced concrete floor slab is mechanically ground to remove surface laitance and impurities, and dust is removed using a vacuum cleaner. P·O42.5 grade ordinary Portland cement, quartz sand, ethylene-vinyl acetate copolymer, hydroxypropyl methylcellulose ether, and polydimethylsiloxane are mixed in a mass ratio of 1:1.2:0.05:0.005:0.002, and water with a material-to-water ratio of 0.25 is added and stirred until homogeneous to obtain a cement-based interface treatment agent.

[0108] Apply cement-based interface treatment agent at a rate of 0.4 kg / m³. 2The coating is evenly applied to the surface of a standard reinforced concrete floor slab and dried and cured for 24 hours at 20℃ to 25℃ to form a base treatment layer. A 5mm thick polyurethane sound insulation pad is then fully laid on the surface of the base treatment layer to form an elastic pad layer. The edge of the polyurethane sound insulation pad extends upwards along the side wall for 30mm. The joints between adjacent polyurethane sound insulation pads are sealed with 50mm wide butyl rubber tape.

[0109] M2: Place 12mm thick composite damping precast panels on the upper surface of the elastic pad layer. Interlock adjacent panels are horizontally joined using the tongue-and-groove structure on the sides of the composite damping precast panels. During the joining process, ensure complete tongue-and-groove engagement without any loose gaps. A 10mm expansion gap is reserved between the edge of the composite damping precast panel and the sidewall. All composite damping precast panels are laid directly using a dry method to form the composite damping precast panel layer.

[0110] M3: Mix P·O42.5 grade ordinary Portland cement, quartz sand, and acrylate emulsion with a solid content of 50% at a mass ratio of 1:1.5:0.5, and add 0.5% of polycarboxylate-based high-efficiency water-reducing agent by mass of cementitious materials. Stir for 5 minutes to form flexible polymer modified cement mortar.

[0111] Pour the flexible polymer-modified cement mortar onto the surface of the composite damping precast panel layer, and use a toothed scraper with a tooth height of 3mm to evenly spread it in the same direction, controlling the coating thickness to 3mm to form a polymer bonding layer. During the spreading process, ensure that the mortar completely covers the splicing gaps of the composite damping precast panel layer.

[0112] M4: Mix hemihydrate gypsum, quartz sand, polycarboxylate superplasticizer, and citric acid in a mass ratio of 1:1.5:0.02:0.005, add water with a water-to-material ratio of 0.30 and stir until the fluidity reaches 190 mm to obtain gypsum-based self-leveling mortar.

[0113] One hour after the polymer bonding layer is applied and in its initial setting state, gypsum-based self-leveling mortar is poured onto the surface of the polymer bonding layer. A screed is used to assist in spreading and controlling the thickness of the gypsum-based self-leveling mortar layer to 10 mm. An air-exploding roller is used to roll on the surface of the mortar to remove internal air bubbles. After curing, a lightweight leveling layer is formed.

[0114] M5: After the formed sample is sealed and cured in an environment with a temperature of 20℃±2℃ and a relative humidity of more than 70% for 24 hours, a 10mm thick solid wood composite wood floor is directly laid on the surface of the lightweight leveling layer. The wood floor is spliced ​​together using the locking structure of the wood floor to form a decorative layer.

[0115] The preparation method of the composite damping precast plate in step M2 is as follows:

[0116] S1: Mix P·O42.5 grade ordinary Portland cement, quartz sand, polypropylene fiber, hydroxypropyl methylcellulose ether and water in a mass ratio of 1:1.5:0.005:0.002:0.35 until a uniform rheological state is reached to obtain the lower layer slurry.

[0117] Waste rubber granules (accounting for 30% of the total aggregate volume) and closed-cell vitrified microspheres (accounting for 20% of the total aggregate volume) were used as aggregates and were forcibly mixed with P·O42.5 grade ordinary Portland cement, ethylene-vinyl acetate copolymer and water at a mass ratio of cement:rubber powder:water of 1:0.01:0.30, and the moisture content was controlled at 10% to obtain a high-damping mixture.

[0118] Closed-cell vitrified microspheres (accounting for 25% of the total aggregate volume) and waste rubber particles (accounting for 15% of the total aggregate volume) were used as aggregates and mixed with P·O42.5 grade ordinary Portland cement, ethylene-vinyl acetate copolymer and water in the same proportion to prepare a scattering-enhanced mixture.

[0119] The surface slurry is prepared by mixing P·O42.5 grade ordinary silicate cement, quartz sand, ethylene-vinyl acetate copolymer and water in a mass ratio of 1:1.5:0.05:0.35.

[0120] S2: Evenly spread the lower layer of slurry on the bottom of the molding mold coated with silicone release agent, with a thickness of 2mm; using a movable dividing material distribution device installed inside the molding mold cavity, simultaneously fill the corresponding horizontal zones with the high-damping mixture and the scattering-enhancing mixture, controlling the material distribution speed at 0.8m. 3 / h; After filling is completed, slowly remove the separating cloth device to allow the high-damping mixture and the scattering-enhancing mixture to naturally mix at the contact interface to form a composite preform with a gradient structure.

[0121] S3: Place the forming mold containing the combined blank on the vibration table and apply mechanical vibration with a frequency of 40Hz and an amplitude of 0.8mm for 45s. After the vibration ends, apply a static pressure of 0.8MPa to the upper surface of the combined blank through a hydraulic press. The pressure rise rate is 0.1MPa / s and the holding time is 8min. Use the convex and concave structure of the edge of the forming mold to press and form a tongue and groove structure to obtain the main body of the semi-finished sheet.

[0122] S4: Using high-pressure spraying equipment, uniformly spray an acrylic emulsion interface agent with a solid content of 50% onto the core layer surface of the semi-finished board body, controlling the spraying amount to 0.25 kg / m². 2 Within 8 minutes after spraying, pour the top layer slurry onto the core layer and smooth it out, controlling the thickness of the top layer to 2mm to form a complete wet board blank.

[0123] S5: Place the complete wet sheet material along with the molding die in an autoclave for autoclaving. Control the saturated steam pressure at 1.0 MPa and the temperature at 180℃, and maintain constant temperature and pressure for 12 hours. After curing, cool down and demold, and continue curing for 3 days in an environment of 20℃±2℃ and relative humidity greater than 70% to obtain a cured sheet material.

[0124] S6: The surface of the top layer of the cured board is mechanically roughened using a shot blasting machine. Steel shot with a particle size of 0.8mm is used to impact the surface under a pressure of 0.4MPa, controlling the roughening depth to 0.8mm and removing loose dust. A solution diluted with γ-aminopropyltriethoxysilane and ethanol at a volume ratio of 1:10 is uniformly sprayed using low-pressure spraying equipment at a spraying rate of 0.15kg / m². 2 The coated panels are placed in a drying oven at 65°C for 3 hours to dry until the solvent is completely evaporated, forming a composite damping precast panel.

[0125] Example 2:

[0126] This embodiment provides a thin floor sound insulation system. The only difference between this embodiment and Embodiment 1 is the preparation parameters of the composite damping precast panels in step M2. All other construction steps and preparation process parameters are the same as in Embodiment 1.

[0127] The difference between the preparation method of the composite damping precast plate in step M2 and that in Example 1 is as follows:

[0128] S1: When preparing the high-damping mixture, the waste rubber particles should account for 40% of the total aggregate volume, and the closed-cell vitrified microspheres should account for 10% of the total aggregate volume. When preparing the scattering-enhancing mixture, the closed-cell vitrified microspheres should account for 25% of the total aggregate volume, and the waste rubber particles should account for 15% of the total aggregate volume. The remaining raw material components, mass ratios, and stirring parameters are exactly the same as in step S1 of Example 1.

[0129] Example 3:

[0130] This embodiment provides a thin floor sound insulation system. The only difference between this embodiment and Embodiment 1 is the preparation parameters of the composite damping precast panels in step M2. All other construction steps and preparation process parameters are the same as in Embodiment 1.

[0131] The difference between the preparation method of the composite damping precast plate in step M2 and that in Example 1 is as follows:

[0132] S1: When preparing the high-damping mixture, the waste rubber particles should account for 50% of the total aggregate volume, and the closed-cell vitrified microspheres should account for 5% of the total aggregate volume. When preparing the scattering-enhancing mixture, the closed-cell vitrified microspheres should account for 25% of the total aggregate volume, and the waste rubber particles should account for 15% of the total aggregate volume. The remaining raw material components, mass ratios, and stirring parameters are exactly the same as in step S1 of Example 1.

[0133] Example 4:

[0134] This embodiment provides a thin floor sound insulation system, which differs from Embodiment 2 only in the construction parameters in step M3. All other construction steps and preparation process parameters are consistent with Embodiment 2.

[0135] The difference between Example 4 and Example 2 is that:

[0136] M3: When applying the flexible polymer-modified cement mortar to form the polymer bonding layer, the coating thickness of the flexible polymer-modified cement mortar is controlled to be 1 mm using a toothed scraper. The remaining mortar proportions, mixing, and application processes are exactly the same as steps M3 in Example 2.

[0137] Example 5:

[0138] This embodiment provides a thin floor sound insulation system, which differs from Embodiment 2 only in the construction parameters in step M3. All other construction steps and preparation process parameters are consistent with Embodiment 2.

[0139] The difference between Example 5 and Example 2 is that:

[0140] M3: When applying the flexible polymer-modified cement mortar to form the polymer bonding layer, the coating thickness of the flexible polymer-modified cement mortar is controlled to be 5 mm using a toothed scraper. The remaining mortar proportions, mixing, and application processes are exactly the same as steps M3 in Example 2.

[0141] Comparative Example 1:

[0142] This comparative example provides a method for preparing a conventional floating floor sound insulation structure, the specific steps of which are as follows:

[0143] M1: A thickness of 120mm and an area of ​​10m² 2 The surface of the standard reinforced concrete floor slab is mechanically ground to remove surface laitance and impurities, and dust is removed using a vacuum cleaner. A bonding agent is then evenly applied to the cleaned surface of the standard reinforced concrete floor slab and allowed to dry and cure for 24 hours to form a base treatment layer.

[0144] M2: A 5mm thick polyethylene foam sound insulation pad is laid on the surface of the base treatment layer to form an elastic pad layer. The edge of the polyethylene foam sound insulation pad extends upward along the side wall for 30mm, and the joints of adjacent polyethylene foam sound insulation pads are sealed with 50mm wide transparent sealing tape.

[0145] M3: A steel mesh with a diameter of 4mm and a spacing of 150mm is laid directly on top of the elastic pad.

[0146] M4: Pour C25 fine aggregate concrete on top of the steel mesh, and use a screed to level and smooth the surface. Control the thickness of the fine aggregate concrete layer to 40mm to form a concrete leveling layer.

[0147] M5: The resulting sample will be sealed and cured for 28 days. After the concrete leveling layer reaches the design strength, a 10mm thick solid wood composite flooring will be laid on the surface of the concrete leveling layer, and spliced ​​together using the interlocking structure of the flooring to form the finishing layer.

[0148] Comparative Example 2:

[0149] The only difference between this comparative example and Example 2 is the material composition in step M3; the other construction steps and preparation process parameters are the same as in Example 2.

[0150] The difference between Comparative Example 2 and Example 2 is that:

[0151] M3: Apply cement mortar to the surface of the composite damping precast slab layer. This cement mortar is prepared by mixing P·O42.5 grade ordinary Portland cement, medium sand, and water in a mass ratio of 1:2.5:0.4, and does not contain acrylic emulsion. Apply the cement mortar evenly to the surface of the composite damping precast slab layer, controlling the coating thickness to 3 mm. The remaining construction process is the same as step M3 in Example 2.

[0152] Comparative Example 3:

[0153] The only difference between this comparative example and Example 2 is the internal structure of the composite damping precast panel in step M2. All other construction steps and preparation process parameters are the same as in Example 2.

[0154] The difference between Comparative Example 3 and Example 2 is that:

[0155] In step M2, the preparation method of the composite damping precast plate does not have a gradient structure in the core layer. The specific changes are as follows:

[0156] S2: Fill the core layer mixture above the lower layer slurry. The core layer mixture is prepared by mixing the high-damping mixture raw material prepared in step S1 of Example 2 with the scattering-enhancing mixture raw material at a 1:1 mass ratio. During the filling process, the moving partitioning material distribution process is eliminated, and the uniformly mixed core layer mixture is filled into the cavity of the molding mold in one go, and pressed to form a homogeneous core layer structure. The remaining preparation steps S1, S3 to S6 are exactly the same as in Example 2.

[0157] Experimental Example 1:

[0158] The floor sound insulation systems prepared in Examples 1-5 and Comparative Examples 1-3 were tested as follows:

[0159] 1. Weighted normalized impact sound pressure level ( Test to quantify the ability to isolate impact noise from floor slabs: According to GB / T50121-2005 requirements, in an area of ​​10m² 2 On a 120mm thick C30 reinforced concrete floor slab test platform, a floor sound insulation system was laid according to the complete schemes of each embodiment and comparative example. All structural layers were cured to the specified age (28 days for cement-based materials and 7 days for polymer materials) before testing. According to GB / T 19889.7-2005, a lightweight impactor (5 steel balls, total mass 2.5kg) conforming to ISO10140-3 was used to evenly distribute 9 test points on the floor surface, with each test point being impacted 3 times. The impact was measured 20m below. 2 In a standard receiving room, sound pressure levels were measured using a Class 1 sound level meter across 16 octave bands from 100Hz to 3150Hz. Background noise correction and normalization were performed according to standard requirements. The corrected weighted normalized impact sound pressure levels were recorded. The unit is decibel (dB), and the result is rounded to one decimal place.

[0160] 2. Improvement in impact sound ( Test: Sample preparation for weighted normalized impact sound pressure level test; according to GB / T19889.8-2006, first measure the weighted normalized impact sound pressure level of the bare floor slab without any sound insulation structure. Subsequently, measurements were taken after the target system was laid. The environmental conditions (temperature 20℃±2℃, relative humidity 50%±10%) were kept consistent in both tests. This was achieved using the formula... The improvement in impact sound was calculated ( The unit is decibel (dB), and the result is rounded to one decimal place.

[0161] 3. Interfacial Tensile Bond Strength Test: Three sets of locally constructed specimens with dimensions of 300mm × 300mm × (plate thickness, adhesive layer thickness, and leveling layer thickness) were prepared according to JGJ / T70-2009. Each specimen contained a complete composite damping precast plate layer, a polymer adhesive layer, and a lightweight leveling layer. After curing for 28 days, the specimens underwent further treatment. 40mm × 40mm test units were cut from the surface of the lightweight leveling layer using a diamond cutter, with the cut depth reaching the surface of the composite damping precast plate layer. Epoxy resin (tensile strength ≥ 30MPa) was used to bond steel pull-out heads, and the units were allowed to stand for 24 hours to ensure a strong bond. An electronic pull-out tester with a range of 0-5kN and an accuracy of 0.01kN was used to apply a vertically upward tensile force to the test units. The loading speed was strictly controlled at 5mm / min, and continuous loading continued until the test units peeled off or failed. The force-displacement curves of the failure process were recorded. Take the average of the maximum loads at failure of the three groups of specimens, and divide it by the stress-bearing area (40mm × 40mm = 1600mm). 2 The stress value obtained is the interfacial tensile bond strength, in megapascals (MPa), and the result is rounded to two decimal places.

[0162] The experimental results are shown in Table 1:

[0163] Table 1 Comparison of Experimental Results

[0164] Group (dB) (dB) Interfacial tensile bond strength (MPa) Example 1 56.5 21.5 1.18 Example 2 51.2 26.8 1.25 Example 3 54.8 23.2 1.05 Example 4 55.0 23.0 0.88 Example 5 53.5 24.5 1.12 Comparative Example 1 64.0 14.0 - Comparative Example 2 58.2 19.8 0.42 Comparative Example 3 59.5 18.5 1.22

[0165] Note: Exposed floor slab It is 78.0 dB.

[0166] Under the condition that the coating thickness of the flexible polymer-modified cement mortar is fixed at 3 mm: Example 1 The value is 56.5 dB. Due to the low rubber particle content, the internal loss factor of the high-damping mixture is insufficient, and the vibrational components in the sound energy are not fully dissipated, resulting in a relatively average sound insulation effect.

[0167] Example 2 The impedance was reduced to 51.2 dB, the best among the three groups. Here, the volume ratio of the rubber particles and the cement matrix formed an optimal balance between damping and stiffness. The high-damping region has sufficient internal friction capacity while maintaining appropriate dynamic stiffness, ensuring acoustic impedance matching with the upper scattering enhancement region, so that the acoustic energy attenuation efficiency of the gradient structure reaches its peak.

[0168] Example 3 The damping level rebounded to 54.8 dB. While the increased rubber content theoretically improved damping, the excessive rubber proportion led to a significant decrease in the density and stiffness of the substructure. This excessive reduction in stiffness altered the system's resonant frequency, shifting it to lower frequencies, potentially coupling with the floor slab's natural frequency. Furthermore, the excessive rubber particles weakened the continuity of the cement skeleton, causing the interfacial tensile bond strength to decrease from 1.25 MPa to 1.05 MPa.

[0169] Assuming the percentage of waste rubber particles in the total aggregate volume is fixed at 40%:

[0170] Example 4 The strength was 55.0 dB, while the interfacial strength was only 0.88 MPa. The 1 mm thickness was insufficient to completely cover the microstructure and seams of the composite damping precast panel surface, leading to localized hard contact points and the formation of acoustic bridges. Simultaneously, the excessively thin polymer mortar layer exhibited poor water retention during curing, hindering the full chemical bridging reaction and resulting in low bond strength.

[0171] Example 2 The strength is 51.2 dB, and the interface strength is 1.25 MPa. The 3 mm thickness forms a continuous and flexible decoupling layer with a certain volume between the composite damping precast slab layer and the lightweight leveling layer, which effectively buffers the transmission of interlayer vibration and eliminates micro-cracks at the interface.

[0172] Example 5 The value was 53.5 dB. While increasing the thickness to 5 mm maintained good bond strength (1.12 MPa), the excessively thick flexible layer increased the system's compressive deformation. Under the influence of sound waves, the thicker intermediate layer may generate its own thickness resonance mode, slightly weakening the efficiency of sound energy transmission to the lower gradient board, resulting in sound insulation performance that is not as good as the 3 mm group.

[0173] Furthermore, in Example 2 The strength reached 26.8 dB, far exceeding the 14.0 dB of the traditional method (Comparative Example 1), due to the performance advantages of this system under the premise of thinness. Comparative Example 2, lacking flexible polymer-modified cement mortar, had an interfacial strength of only 0.42 MPa, and... The degradation to 58.2 dB is due to the fact that without the flexible modulus transition and chemical bridging provided by waste rubber particles, the rigid interface is not only prone to peeling, but also generates sound wave reflection due to stress concentration, hindering sound energy from entering the gradient plate for attenuation. Comparative Example 3, due to the uniform distribution of the core layer, The value is 59.5dB, which is due to the fact that a single homogeneous material cannot simultaneously achieve wide-bandwidth scattering and damping within a thickness of 10-15mm.

[0174] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A thin floor sound insulation system, characterized in that, From bottom to top, it includes a base treatment layer, an elastic pad layer, a composite damping precast panel layer, a polymer bonding layer, a lightweight leveling layer, and a finishing layer. The base treatment layer is formed by a cement-based interface treatment agent that is cured on the surface of the floor base layer; The elastic padding layer is laid on top of the base treatment layer; The composite damping prefabricated plate layer is disposed above the elastic pad layer and is spliced ​​together from the composite damping prefabricated plates; The polymer bonding layer is disposed between the composite damping precast slab layer and the lightweight leveling layer, and is formed by curing flexible polymer modified cement mortar; The lightweight leveling layer is disposed above the polymer bonding layer and is formed by curing gypsum-based self-leveling mortar.

2. The thin floor sound insulation system according to claim 1, characterized in that, The total thickness of the composite damping precast plate is 10 to 15 mm, and it includes a bottom layer, a core layer and a top layer from bottom to top. The lower layer includes cement as a hydraulic cementitious material, waste rubber particles as an elastic damping component, redispersible latex powder as a film-forming binder component, and damping plate additives. The core layer exhibits a continuous, gradual transition from the high-damping mixture region near the lower layer to the scattering-enhancing mixture region near the upper layer; The top layer is composed of a cement-based material whose surface has been mechanically roughened and coated with a silane interface activator.

3. The thin floor sound insulation system according to claim 2, characterized in that, The core layer is composed of a high-damping mixture and a scattering-enhancing mixture, both of which include waste rubber particles and closed-cell vitrified microspheres. In the high-damping mixture, waste rubber particles account for 30% to 50% of the total aggregate volume, and closed-cell vitrified microspheres account for 5% to 20% of the total aggregate volume; In the scattering-enhanced mixture, closed-cell vitrified microspheres account for 20 to 30% of the total aggregate volume, and waste rubber particles account for 10 to 20% of the total aggregate volume.

4. A thin floor sound insulation system according to claim 2, characterized in that, The silane interface activator is specifically γ-aminopropyltriethoxysilane; the damping plate additive includes polypropylene fiber and hydroxypropyl methylcellulose ether.

5. A thin floor sound insulation system according to claim 1, characterized in that, The polymer adhesive layer is formed from flexible polymer-modified cement mortar.

6. A thin floor sound insulation system according to claim 1, characterized in that, The elastic padding layer is a polyurethane sound insulation pad.

7. A thin floor sound insulation system according to claim 1, characterized in that, The finishing layer is wood flooring or polyvinyl chloride roll material.

8. A construction method for a thin floor sound insulation system according to any one of claims 1 to 7, characterized in that, Includes the following steps: M1: Clean and treat the base layer of the floor and surface, and lay polyurethane sound insulation pads to form a base treatment layer and an elastic pad layer. M2: The composite damping precast panels are dry-laid on top of the elastic pad layer by tongue and groove splicing to form a composite damping precast panel layer; M3: Apply flexible polymer-modified cement mortar to the surface of the composite damping precast panel layer to form a polymer bonding layer; M4: Pour gypsum-based self-leveling mortar onto the surface of the polymer bonding layer to form a lightweight leveling layer; M5: Curing the lightweight leveling layer and laying finishing materials on the surface of the lightweight leveling layer.

9. The construction method of a thin floor sound insulation system according to claim 8, characterized in that, The composite damping precast plate mentioned in step M2 is prepared through the following steps: S1: Prepare the lower layer slurry, high-damping mixture, scattering-enhancing mixture and upper layer slurry; S2: The lower layer slurry is laid on the bottom of the molding die. The high-damping mixture and the scattering-enhancing mixture are simultaneously laid on the upper layer slurry through a separation material laying process to obtain the combined initial blank. S3: Apply mechanical vibration and static pressure to the combined billet to obtain a semi-finished sheet metal body with tongue and groove structure; S4: Spray an interface agent onto the surface of the core layer of the semi-finished board and pour the top layer slurry to obtain a complete wet board blank. S5: Curing the wet blank of the complete board to obtain a cured board; S6: The surface of the upper layer of the cured board is mechanically roughened and chemically activated to obtain a composite damping precast board.

10. The construction method of a thin floor sound insulation system according to claim 9, characterized in that, In step S6, the mechanical roughening depth is controlled between 0.5 and 1.0 mm, and the chemical activation treatment is spraying a γ-aminopropyltriethoxysilane solution.

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