木结构墙体空气声隔声性能

Investigation of Airborne Sound Insulation Performance in Timber Structure Walls

【目的】研究全频段范围内木结构墙体空气声隔声性能,明确限制常规构造木骨架墙体隔声性能的瓶颈,揭示设置隔声垫层、改变骨架类型、设置窗体等设计参数对墙体隔声性能的影响规律,提出高空气声隔声等级的木结构墙体体系,为木结构墙体在装配式建筑中的高效应用提供技术支撑。【方法】通过小尺寸材料层面的阻抗管法试验,比较分析60~6300 Hz频率范围内工业级弹性橡胶板(橡胶板)、聚氨酯橡胶隔音减震板(聚氨酯板)和聚苯乙烯挤塑板(XPS板)等隔声垫层的隔声性能;基于实验室法开展全尺寸墙体在100~5000 Hz频率范围内的隔声试验,通过1/3倍频程频段18个中心频率对应的单值隔声量,得到墙体计权隔声量(R_(w))、频谱修正量和隔声等级,并与装配式建筑中广泛应用的蒸压加气混凝土(ALC)墙体和正交胶合木(CLT)墙体进行比较。【结果】相较同一厚度的聚氨酯板和XPS板,全频段范围内橡胶板的隔声量较高,且其隔声性能随板厚增加而提高,试验范围内,10 mm厚橡胶板隔声效率最高。常规构造木骨架墙体的隔声量整体上随声波频率增加而提高,该墙体体系在125和3150 Hz处分别出现明显的共振隔声低谷和吻合隔声低谷,其R_(w)为43 dB,用作隔墙或围护构件时的空气声隔声等级分别为4和3级;在墙骨架和定向刨花板(OSB)间设置10 mm厚橡胶板后,受制于木龙骨的声桥作用,墙体隔声性能提升有限,R_(w)增至45 dB,隔声等级未发生改变,常规构造和设置橡胶板的木骨架墙体体系均不满足现行国家标准对普通住宅墙体的隔声要求。当墙骨架采用轻钢骨架且轻钢骨架两侧均覆面双层石膏板(GB)时,该墙体体系的R_(w)增至50 dB,用作隔墙或围护构件时的空气声隔声等级分别升至6和5级;在石膏板和轻钢骨架间设置10 mm压缩玻璃棉条后,R_(w)增至51 dB,隔声等级未发生改变,该轻钢骨架墙体体系满足现行国家标准对普通住宅墙体的隔声要求。与200 mm厚单层和复合ALC墙体相比,试验范围内轻钢骨架墙体的厚度和面密度分别降低35%和70%,但空气声隔声性能更高;针对道路交通、企业生产经营和日常生活等噪音对应的频率范围(160~630 Hz),该轻钢骨架墙体体系的隔声性能增加明显。在常规构造木骨架墙体基础上开洞安装R_(w)为33 dB的窗体,墙体在全频段范围内的隔声频谱特性曲线未发生明显变化,其R_(w)达44 dB,用作隔墙或围护构件时的空气声隔声等级分别为5和4级;常规构造木骨架墙体一侧的GB由单层增至双层、木骨架和OSB间设置10 mm厚橡胶板、木骨架和GB间设置金属减震龙骨制成复合墙体,在复合墙体上安装窗体,该墙体的R_(w)增至48 dB,且在低频段下的共振隔声低谷和高频段下的吻合效应低谷消除或明显变浅,用作隔墙或围护构件时的空气声隔声等级分别升至6和5级,满足现行国家标准对普通住宅墙体的隔声要求。【结果】与木骨架墙体相比,CLT墙体的空气声隔声性能较低;共振隔声低谷、吻合隔声低谷和声桥效应是限制常规构造木骨架墙体隔声性能的瓶颈因素,导致该墙体体系不能满足现行国家标准对普通住宅墙体的隔声要求。将木骨架替换为轻钢骨架,并设置隔声垫层、增加墙面板数量,能够有效提高墙体的空气声隔声性能。

【Objective】The airborne sound insulation performance of timber structure walls is investigated across a full frequency range.It aims to identify the bottlenecks limiting the sound insulation of conventional light wood frame walls,explore the effect of installing sound insulation layers,altering frame type,and setting up windows on wall sound insulation performance,and propose a high airborne sound insulation grade timber wall system.This research provides technical support for the efficient application of timber structure walls in prefabricated buildings.【Method】Using the impedance tube method,small-scale material layer experiments were conducted to compare the sound insulation performance of industrial-grade elastic rubber sheets(rubber sheets),polyurethane rubber soundproofing and shock-absorbing sheets(polyurethane sheets),and polystyrene extruded sheets(XPS sheets)within the 60-6300 Hz frequency range.Full-scale walls sound insulation tests were performed using in the 100-5000 Hz frequencies range using the laboratory method.We obtained single-value sound insulation levels for 18 central frequencies in 1/3 octave bands,determining the wall’s weighted sound insulation index(R_(w)),spectrum adaptation terms,and sound insulation grades.These were compared with autoclaved lightweight concrete(ALC)walls and cross-laminated timber(CLT)walls widely used in prefabricated buildings.【Result】The rubber sheet showed higher sound insulation across the full frequency range compared to the same thickness polyurethane and XPS sheets,with sound insulation performance improving with increased sheet thickness.A 10 mm thick rubber sheet exhibited the highest sound insulation efficiency within the test range.The sound insulation of conventional light wood frame walls increased with sound wave frequency but exhibited significant resonant sound insulation dips at 125 Hz and coincident dips at 3150 Hz,with an R_(w) of 43 dB.When used as partitions or enclosures,the airborne sound insulation grades were 4 and 3,respectively.Adding a 10 mm thick rubber sheet between the wall frame and oriented strand board(OSB)slightly improved the sound insulation(R_(w) increased to 45 dB),but the grade remained unchanged.Conventional light wood frame walls with and without rubber sheets did not meet current national standards for sound insulation in ordinary residential walls.When using a light steel frame with double gypsum board(GB)on both sides,the R_(w) increased to 50 dB,raising the airborne sound insulation grades to 6 and 5 for partitions and enclosures,respectively.Adding 10 mm compressed glass wool strips between the GB and light steel frame further increased R_(w) to 51 dB,meeting national standards for residential wall sound insulation.Composite to 200 mm thick single-layer and composite ALC walls,the thickness and surface density of light steel frame walls decreased by 35%and 70%,respectively,while achieving higher sound insulation.In the 160-630 Hz frequency range corresponding to noise from road traffic,industrial operations,and daily life,the light steel frame walls system showed significantly improved sound insulation.Installing a window with an R_(w) of 33 dB in a conventional light wood frame wall did not significantly change the full-frequency sound insulation curve,with an R_(w) of 44 dB,raising the sound insulation grades to 5 and 4 for partitions or enclosures,respectively.Converting the GB on one side of the conventional light wood frame wall to double-layered,adding a 10 mm thick rubber sheet between the wood frame and OSB,and setting up a metal damping keel between the wood frame and GB created a composite wall with a window.This wall achieved an R_(w) of 48 dB,eliminating or significantly reducing the low-frequency resonance dips and high-frequency coincidence dips,raising the sound insulation grades to 6 and 5,respectively,meeting national standards for residential walls.【Conclusion】Compared to light wood frame walls,CLT walls exhibit lower airborne sound insulation performance.Resonance dips,coincidence dips,and sound bridging effects are the key factors limiting the sound insulation performance of conventional light wood frame walls,preventing them from meeting national standards for residential walls.Replacing wood frames with light steel frames,installing sound insulation layers,and increasing the number of wall panels effectively improve wall airborne sound insulation performance.