Research on sound insulation and heat insulation performance of steel structure buildings in Xinjiang

1. Introduction

Xinjiang steel structure buildings are widely used in industrial plants, high-rise buildings, long-span venues and other fields due to their advantages of light weight, high strength, efficient construction, and green environmental protection. However, as a material with a high thermal conductivity (approximately 50W/(m·K), which is much higher than the 1.5W/(m·K) of concrete and 0.12W/(m·K) of wood), steel has inherent thermal bridge effects and vibration transmission characteristics, causing sound and thermal insulation performance to become a key bottleneck restricting the comfort of steel structure buildings. As the “double carbon” goal advances and the demand for living quality increases, how to break through this shortcoming through material innovation, structural optimization and technology integration has become an important research direction in the field of architecture.

2. Sound insulation performance challenges and optimization strategies of steel structure buildings

1. Core issues of sound insulation performance

The sound insulation shortcomings of steel structures are mainly due to two points: the editor of Xinjiang Steel Structure Manufacturer said that firstly, the rigid connection characteristics of steel cause vibration to be efficiently transmitted along the beam and column system, causing the "solid sound bridge" effect; secondly, envelope structures (such as profiled steel plates, lightweight partition walls) generally have the characteristics of light weight and low stiffness, and insufficient blocking ability against air sound (usually only meet the weighted sound insulation amount of 25-30dB, which is lower than the 40dB required by civil building regulations).

2. Structure-borne sound control technology

(1) Vibration isolation design: Set elastic damping materials (such as butyl rubber, polyurethane foam) at the connection between steel components and the enclosure structure to reduce the efficiency of solid-state sound transmission by increasing the damping loss in the vibration transmission path. The editor of Xinjiang Steel Structure said that experiments show that the floor sound insulation structure using 5mm thick neoprene rubber pad can reduce the impact sound pressure level from 85dB to 65dB, meeting the first-level standard for residential buildings in GB/T 50121-2005.

(2) Floating floor system: It adopts a composite structure of "steel frame + elastic cushion + concrete superimposed layer", and uses elastic cushion (such as glass wool felt, spring shock absorber) to decouple the floor slab from the steel main beam. A case of a high-rise steel structure residential building shows that this system can increase the impact sound insulation in the 100-3150Hz frequency band by 15-20dB, which is better than the traditional rigid connection structure.

3. Air sound control technology

(1) Optimization of lightweight composite walls:The editor of Xinjiang steel structure manufacturer saidThe sandwich structure of "profiled steel plate + sound-absorbing cotton + gypsum board" was developed to increase the sound insulation amount by increasing the surface density of the material (such as using 0.8mm thick galvanized steel plate + 12mm gypsum board) and the thickness of the air layer (100-150mm). Test data shows that when the air layer is filled with 50mm thick centrifugal glass wool (density 48kg/m³), the weighted sound insulation of the wall can reach 42dB, meeting the five-star hotel standard of GB/T 50356-2005.

(2) Hole sealing and gap treatment: Gaps in steel structure nodes (such as bolted connections and pipeline crossings) are the main paths for air sound leakage. Using intumescent fireproof sealant (expansion ratio ≥ 250%) and sound insulation putty to treat gaps can increase the overall sound insulation by 3-5dB, especially the blocking effect on high-frequency sounds (above 1000Hz) is significant.

3. Thermal insulation performance bottlenecks and breakthrough paths of steel structure buildings

1. Key contradictions in thermal insulation performance

The high thermal conductivity of steel structures in Xinjiang leads to a prominent thermal bridge effect. In winter, heat is quickly lost through steel columns and steel beams. In summer, high outdoor temperatures enter indoors through heat conduction, increasing building energy consumption by 30%-40%. Taking a steel structure factory building in a severe cold area as an example, without thermal insulation treatment, the heat transfer coefficient (K value) of the building envelope in winter reaches 3.5W/(m²·K), far exceeding the 0.35W/(m²·K) required by GB 50189-2015.

2. Thermal bridge blocking technology

(1) Thermal bridge connectors: Connectors made of fiberglass reinforced plastic (FRP) or polyamide (PA66+25% glass fiber) to replace traditional steel connectors. The thermal conductivity of FRP is only 0.3W/(m·K), which can reduce the thermal bridge heat transfer loss between steel columns and exterior wall panels by more than 60%. After applying this technology to a low-temperature storage project, the K value of the building envelope dropped from 1.8W/(m²·K) to 0.45W/(m²·K).

(2) Cold bridge wrapping structure:The editor of Xinjiang steel structure manufacturer saidSteel components exposed to the outdoors (such as roof purlins and parapet steel brackets) are wrapped with high-density polyurethane foam (density ≥ 40kg/m³, thermal conductivity ≤ 0.024W/(m·K)), with a thickness of not less than 50mm, and an aluminum foil reflective layer to reduce radiation heat transfer, which can reduce the local heat flux density from 15W/m² to less than 3W/m².

3. Innovation in thermal insulation system of building envelope

(1) Vacuum insulation panel (VIP) integration technology: Composite the VIP panel (thermal conductivity ≤ 0.008W/(m·K)) with the profiled steel plate to form an ultra-light and thin insulated roof of "steel plate + VIP + air layer". After application in a large-span convention and exhibition center project, the K value of the roof reached 0.18W/(m²·K), which is 40% lighter than the traditional rock wool roof (K=0.5W/(m²·K)) and reduced the pressure of the roof load on the steel purlins.

(2) Phase change material (PCM) energy storage wall: Fill the cavity of the double-layer steel wall panel with paraffin-based PCM (phase change temperature 20-26°C, latent heat ≥180kJ/kg), which absorbs/releases heat through the material phase change process and reduces indoor temperature fluctuations. Experiments show that the wall can reduce the peak indoor temperature in summer by 3-5°C and reduce the air conditioning load by 25%. It is especially suitable for steel structure buildings in areas with hot summers and warm winters.

4. Collaborative technology and engineering verification for performance improvement

1. Integrated design method

Use BIM technology to establish a "material-structure-performance" coupling model, predict the location of thermal bridges through thermal imaging simulation (such as ANSYS Fluent software), and optimize the material combination combined with sound insulation spectrum analysis (using the impulse response method). A certain steel structure office building project used this method to reduce the K value of the exterior wall from 0.6W/(m²·K) to 0.3W/(m²·K), while the weighted sound insulation was increased to 45dB, and the comprehensive construction cost increased by less than 8%.

2. Project case verification

(1) A steel structure ultra-low energy consumption house in Beijing adopts the "spring-absorbing floating floor + VIP vacuum insulation roof + FRP thermal insulation bridge connector" technical system. The measured winter heat transfer coefficient K=0.15W/(m²·K), the impact sound insulation amount is 62dB, reaching the German Passive House Standard (PHI), and the annual heating energy consumption is only 15kWh/(m²·a).

(2) A steel structure cultural and creative park in Shenzhen: Applying "PCM phase change wall + composite sound insulation curtain wall", the indoor temperature fluctuation in summer is ≤2℃, the NRC (noise reduction coefficient) reaches 0.8, meeting the acoustic requirements of the concert hall level, and won the "Green Building Innovation Award".

5. Conclusion and outlook

To improve the sound insulation and heat insulation performance of steel structure buildings, it is necessary to break through the multi-dimensional limitations of "material-structure-system": elastic damping technology is used to block solid sound transmission, and composite lightweight materials improve airborne sound insulation;The editor of Xinjiang steel structure manufacturer saidThe thermal bridge design and high-efficiency insulation materials are used to solve the thermal bridge problem, and the dynamic thermal insulation performance is optimized by combining phase change energy storage technology. Future research should focus on the engineering application of ultra-high-performance materials such as nano-aerogels, as well as the development of intelligent adjustable sound insulation and heat insulation systems (such as electrochromic insulation glass), to promote the development of steel structure buildings in the direction of "ultra-low energy consumption and high comfort".

(The full text is about 1020 words)