常用楼板隔声材料的撞击声隔声性能测试分析

通过对隔声涂料、隔声砂浆以及隔声垫3种工程中常用的楼板隔声材料进行现场撞击声隔声测试分析,并对其性能特点、施工工艺以及综合成本等方面进行比较分析.结果表明:隔声涂料施工方便、造价成本低、隔声效果好;隔声砂浆施工便捷,可代替找平层,代替干硬砂浆铺贴瓷砖;隔声垫隔声效果最好,但施工工艺较为复杂,造价成本高.在实际应用中,应...     

住宅外门窗隔声做法研究

分析了住宅外门窗的隔声作用,并通过叙述专业隔声门窗的结构形式及设计,对住宅外门窗隔声做法进行了研究,从而使住宅外墙整体隔声量得到提高,保证隔声效果。     

建筑隔声砂浆的性能研究

依据墙体空气声隔声基本原理,研制了一种隔声砂浆。通过变化隔声砂浆中不同添加剂及其不同用量的对比,分析了各种添加剂对隔声性能的影响。将隔声砂浆抹在隔声量较低的轻质墙体上,获得了提高隔声量的效果。隔声砂浆中添加了橡胶丝、硅粉及偶联剂、金属粉、苯丙乳液等添加剂,文章从微观角度分析了隔声砂浆的隔声机理及各种添加剂的作用。     

建筑隔声砂浆的性能研究

依据墙体空气声隔声基本原理,研制了一种隔声砂浆.通过变化隔声砂浆中不同添加剂及其不同用量的对比,分析了各种添加剂对隔声性能的影响.将隔声砂浆抹在隔声量较低的轻质墙体上,获得了提高隔声量的效果.隔声砂浆中添加了橡胶丝、硅粉及偶联剂、金属粉、苯丙乳液等添加剂,文章从微观角度分析了隔声砂浆的隔声机理及各种添加剂的作用.     

基于隔声涂料的楼地面隔声贴砖系统研究

为实现地铁站后勤室楼地面撞击声隔声降噪，研究了不同类型乳液、不同隔声填料配比对隔声涂料隔声效果的影响。基于隔声涂料复合楼面找平贴砖一体化测试了隔声涂料、找平砂浆、石膏自流平、水泥自流平、轻质砂浆贴砖系统的隔声性能。结果表明，在乳液固含量相同条件下，乳液的玻璃化转变温度（Tg）越低，隔声效果越好；4%蛭石和35%橡胶颗粒的加入可以有效提高隔声涂料的隔声效果；在砂浆中添加乳液可以有效提高系统的隔声效果；隔声涂料体系结合半干砂浆贴砖体系，使楼地面隔声效果达到67 dB，可应用于地铁站后勤休息室的隔声构造。     

砌体结构的隔声性能

本文讨论了砌体结构的隔声性能、最佳性能优化设计及隔声砌块的发展。砼砌体的声音传递等级高，如果在砼砌体中引入隔声措施，则砼砌体的隔声效果更加显著。     

隔声楼面施工技术

隔声减震垫是一种弹性闭孔结构的垫层材料,在楼板上铺设这种垫层材料能有效降低楼板撞击声压传播,满足使用要求。介绍隔声楼面的构造、施工质量控制要点。     

楼板隔声材料的撞击声隔声实验室测量结果研究

隔声降噪问题越来越成为住宅品质的关注方向,尤其是上下楼层之间的撞击声隔声,隔声地板、隔声砂浆、隔声涂料及隔声垫等隔音材料应运而生。本文对比了这4种产品的计权撞击声压级和计权撞击声压级改善量的实验室测试结果。结果表明,这4种隔音材料的隔声效果、隔声原理和施工要求各有特点,在一定厚度、一定密度下均能改善基础分户楼板的计权撞击声压级,并达到标准要求。     

隔声楼面的施工技术

介绍了隔声楼面的构造、施工质量控制要点.隔声减震垫是一种弹性闭孔结构的垫层材料,在楼板上铺设这种垫层材料能有效降低楼板撞击声压传播,满足使用要求.     

双层墙体的隔声反演

对于隔声要求高的建筑,可以考虑双层墙结构。双层墙结构的隔声量可应用统计能量分析(SEA)进行预测,但具体设计往往是隔声的反演过程,即已知隔声要求来确定双层隔声构造和材料。本文作者应用人工免疫算法建立反演模型,对双层墙结构的各层墙的面密度、厚度、弹性模量和空腔的厚度等参量进行预测,然后,以这些参数决定双层墙隔声结构的材料及构造形式。     

全波形声发射技术用于混凝土材料损伤监测研究

在研究了混凝土材料三点弯曲试验下声发射累积能量随载荷变化关系曲线的基础上,提取了混凝土材料不同破坏阶段的全波形声发射信号并分析了其频谱特性,并且通过与参数分析结果的比较,发现全波形声发射信号能够实时反映混凝土材料在载荷作用下破坏过程的特征信息。     

Environmental impact of acoustic materials in residential buildings

This study examines the differences in environmental impact between various architectural acoustic materials in residential buildings, considering both embodied and operational Ecopoints using Envest. Five building types were compared, including bungalow, detached, semi-detached, terraced, and apartments. For each building type, two typical wall materials (brick and stone) which have a similar sound transmission loss, and three levels of glazing ratio were compared. For the apartment building, further analysis was made considering three wall types (brick, concrete and glass curtain), two roof types (pitched and flat) and different numbers of storeys (2–4). More detailed analysis was then carried out for two typical rooms, a living room and a bedroom, considering different combinations of interior finishing materials, but with the same reverberation time and sound transmission loss. The results of this study demonstrate the importance of considering the environmental sustainability of various acoustic materials. Although individual components may not affect the total Ecopoints greatly, when every acoustics-related component in a building is taken into account, significant differences in Ecopoints could be made with a better selection of architectural acoustic materials/components from the viewpoint of environmental sustainability, so that the environmental impact could be reduced to the minimum while the acoustic performance is kept the same.     

Damage assessment for concrete structure using image processing techniques on acoustic borehole imagery

The deterioration of concrete structures is a growing problem worldwide. Drilled cores are usually collected from large dams for testing the concrete and rock foundation underneath to assess their safety. However, the borehole itself can be used to assess cracks and other damage and collect additional information on the surrounding materials. This paper evaluates various edge-detection algorithms, as well as transform and statistical-based methods, for their effectiveness in assessing damage in a concrete dam from digital borehole imagery obtained using an acoustic televiewer. The statistical-based approach was found to be the most efficient technique for damage assessment from acoustic imagery. A clustering technique was used to quantify damage from the imagery, such as vertical cracks, horizontal cracks, voids, stains, and foundation damage. Results were verified using log data. Further damage analysis consisted of determining minimum, maximum and mean crack-width openings.     

Brandverhalten von Hohlkastendecken aus Holz

Fire behaviour of timber slabs made of hollow core elements. This paper presents an overview of experimental tests on the fire behaviour of timber slabs made of hollow core elements. The fire tests aim at supplying basic data and information for an extended safe use of timber structures, particularly in multi‐storey buildings. A series of large scale fire tests on timber slabs was performed by the Institute of Structural Engineering of the Swiss Federal Institute of Technology Zurich in order to enlarge the experimental background of the design methods for a fire resistance of 60 and more minutes. Further a series of small scale fire tests permitted to investigate the fire performance of different types of joints between the timber elements, the influence of acoustic perforations as well as the fire behaviour of hollow core elements filled with different insulation materials.     

In situ acoustic performance of materials used in Brazilian building construction

The present study has the goal of showing the acoustic performance of materials routinely used in Brazilian building construction. In situ measurement procedures are presented for the determination of acoustic performance of the materials. Measurements were performed according to the standards ISO 140-4, ISO 140-5, and ISO 717-1. The results were compared with values for sound insulation prescribed by the German Standard DIN 4109. The performance of Brazilian building materials were shown to be below international standards of acoustical quality.     

Acoustic of monolithic dome structures

Monolithic dome structures were built in the 1970s in Europe and America. These dome structures share common benefits of being cost-efficient, earth-friendly, extremely durable, and easily maintained. Monolithic shells are easily constructed and are extremely cost-effective. Monolithic domes respond efficiently to any climate, even to extremely cold or hot temperatures. In terms of utility savings, monolithic domes can cut electricity consumption by up to one-third, thereby saving 60–70% of total energy costs. Moreover, monolithic structures provide the highest survivability rates from destructions. The interior of monolithic domes have perfect, concave shapes to ensure that sound travels through the dome and perfectly collected at different vocal points. These dome structures are utilized for domestic use because the scale allows the focal points to be positioned across daily life activities, thereby affecting the soni ccomfort of the internal space. This study examines the various acoustic treatments and parametric configurations of monolithic dome sizes. A geometric relationship of acoustic treatment and dome radius is established to provide architects guidelines on the correct selection of absorption needed to maintain the acoustic comfort of these special spaces.     

室内音质设计中新材料应用实践

在室内音质设计中,吸声材料起到控制混响时间和吸声降噪的作用。近年来,随着声学材料水平和室内声学装修设计水平的大幅提升,越来越多兼具良好吸声性和美观性,且卫生环保的新型吸声材料进入声学装修市场。本文介绍了4种新型吸声材料通过混响室法测得的吸声特性,并结合实际工程项目,介绍了它们在室内音质设计中的应用效果。     

Acoustic emission to assess and monitor the integrity of bridges

Increased axle loads and traffic density necessitate strengthening and widening of traditional masonry arch bridges. The question remains as to how to evaluate the condition of a bridge and assess the effect of modern traffic on its serviceability? The focus of this paper has been the evaluation of the potential for the acoustic emission technique to provide cost effective in-situ long term monitoring of bridge condition. The work was performed on a bridge chosen to be representative of both masonry and reinforced concrete construction methods. The results demonstrate that acoustic emission technique can be applied to condition assessment of bridges. These results confirm that strong acoustic emission signals are obtained from reinforced concrete structures and demonstrate that acoustic emissions can be detected in masonry structures but at lower energy levels. The experimental programme has shown that AE is useful in detecting crack growth and determining the position of the crack tips at a much earlier stage in their development, before they are noticed during visual inspection     

Prediction of elastic and acoustic behaviors of calcarenite used for construction of historical monuments of Rabat,Morocco

Natural materials (e.g. rocks and soils) are porous media, whose microstructures present a wide diversity. They generally consist of a heterogeneous solid phase and a porous phase which may be fully or partially saturated with one or more fluids. The prediction of elastic and acoustic properties of porous materials is very important in many fields, such as physics of rocks, reservoir geophysics, civil engineering, construction field and study of the behavior of historical monuments. The aim of this work is to predict the elastic and acoustic behaviors of isotropic porous materials of a solid matrix containing dry, saturated and partially saturated spherical pores. For this, a homogenization technique based on the Mori–Tanaka model is presented to connect the elastic and acoustic properties to porosity and degree of water saturation. Non-destructive ultrasonic technique is used to determine the elastic properties from measurements of P-wave velocities. The results obtained show the influence of porosity and degree of water saturation on the effective properties. The various predictions of Mori–Tanaka model are then compared with experimental results for the elastic and acoustic properties of calcarenite.     

Micro–macro fracture relationships and acoustic emissions in concrete

In this work we are interested in how micromechanical phenomena affect bulk mechanical properties. Specifically we are interested in microfracture characteristics and how they influence damage evolution and fracture toughness. Toward this end, quantitative acoustic emission techniques were used to measure microfracture properties in an array of cement-based materials of varying microstructure. Microcracks were modeled using a seismic moment tensor, which could be estimated through deconvolution of the measured acoustic emission waveforms. Results of the experiments indicate that materials with higher bulk fracture toughness had larger numbers of sliding mode microcracks, while materials with lower bulk fracture toughness had fewer numbers of tensile mode microcracks.