Sound Insulation Requirements Research Articles

Effects of waste rubber particles on workability, mechanical, and sound insulation properties of recycled aggregate mortar

The influence mechanism of waste rubber particles (WRPs) on the workability, mechanical properties, and sound insulation performance of recycled aggregate sound insulation mortar (RCM) were investigated. According to the principle of volume fraction replacement of recycled fine aggregate by 0 to 50%, WRPs with a particle size of 1–4 mm were incorporated in various mixtures of RCM. Each RCM mixture was tested for workability, mechanical, and sound insulation performance. Mercury intrusion porosimetry was used to analyze the distribution of pores and their sizes inside the material, and X-ray diffraction and scanning electron microscopy were used to analyze the characteristics of the interfacial transition zones (ITZs) between the rubber particles and the cement paste. The results showed that, owing to the hydrophobicity of WRPs, greater WRPs content led to greater fluidity of the mortar mix and a smaller water retention rate. Notably, the rubber in the mortar did not contribute to the hydration reactivity of the cement paste, but it changed the crystal morphology and pore structure of ITZ hydration products. The RCM incorporating 3–10% WRPs produced the optimal pore structure through the aggregate effect, which increased its overall compactness and mechanical performance. Further increase of WRP content significantly improved the sound insulation performance while significantly reducing the strength. Moreover, there was a clear logarithmic relationship between the strength and impact sound level index. This new knowledge can be used to prepare RCM that meets the actual strength and sound insulation requirements of the floor. Thus, the resource utilization of solid waste can be expanded.

Development of a new acoustic prediction tool by integration of life cycle assessment

Recently, environmental awareness has been the key driver for using renewable materials that have low environmental impact and fulfill constructional requirements, such as timber. Despite the advantages of wood as a building material, it has a lower subjective quality of sound insulation. To fulfill the sound insulation requirements, it is, therefore, unavoidable to complement based-wooden assemblies with additional element(s). However, identifying the acoustic performance is costly and time-consuming. Therefore, developing an accurate prediction tool is vital. Since wood-based structures have been developed to consider the environmental aspects, the environmental performance of buildings should be integrated into the acoustic design. This paper aims to develop an acoustic design methodology for wooden structures using artificial neural network approach by integration of life cycle assessment (LCA). Various Lab-based measurements are used to develop the acoustic prediction tool. Then, a LCA study is conducted on the test assemblies. This paper initially found that wooded assemblies generally increase the environmental impacts to achieve better acoustic insulation. Moreover, different assemblies can meet the sound insulation requirements. Therefore, designers should cognize of environmental and acoustic trade-off by selecting assemblies that consider both aspects.

Sound flanking through common low-voltage electrical conduit in multi-family residential buildings

Sound flanking between suites in multi-family residential buildings is a prevalent issue in architectural acoustics and building construction that can decrease the sound insulation performance of suite-demising partitions, compromising acoustical privacy and comfort for residents. In recent times, a specific deficiency regarding the sealing of common low-voltage electrical conduit routed between residential suites has been increasing in frequency in construction of residential buildings, resulting in otherwise appropriately designed suite demising configurations performing poorly in situ, and in some cases, even failing Ontario Building Code requirements for sound insulation between dwelling spaces during site testing. This article presents test data sampled from multiple residential buildings in Ontario, highlighting the extent of this issue and its implications, along with discussion regarding the proactive prevention and post-construction rectification of this issue.

Traffic noise transmitted indoors

In numerous countries, traffic noise is widely acknowledged as a highly disturbing form of pollution. Given that individuals spend a substantial portion of their day indoors, the impact of traffic noise perceived indoors is of considerable significance. To establish appropriate sound insulation requirements for buildings, it is essential to correlate subjective annoyance with objective ratings. This paper aims to present the regulations implemented by various countries and present preliminary findings from ongoing studies that involve listening tests using either measured or simulated traffic noise in indoor environments.

FIELD TESTS OF IMPACT NOISE INSULATION OF THE FLOOR USING PLANNING THEORY

In modern construction, one of the main indicators of the quality of housing for users of multi-storey buildings is still noise. The task of preventing the noise that occurs in the house itself needs to be given more attention when designing and soundproofing. It is known that extraneous sounds penetrating into a living space cause a negative impact not only on the psychological state of a person, but also on the physical one. In this regard, each user of the premises wants to receive comfortable conditions for staying in them. To achieve this condition, it is necessary to develop effective structural and technological schemes for soundproofing the floor from impact noise, as well as their verification and evaluation using the theory of planning experiments. This article is devoted to solving an important issue of sound insulation of floors in monolithic reinforced concrete multi-storey residential buildings, namely from impact noise. The article considers the structural and technological schemes of sound insulation of the floor of fifteen types, using different materials and their combinations to achieve regulatory requirements for sound insulation from impact noise. It was determined that the thickness of the layer of materials and the density have a significant effect on the insulation performance against shock noise. The work investigated floor constructions based on layers of changing materials. Specifically, such parameters as the thickness (50±10 mm) and density (300±50 kg/m3) of polystyrene concrete "Izolkap" and the thickness of the semi-dry screed (50±10 mm). When choosing the most rational design and technological scheme used the results of planning theory, as well as indicators of reduced impact noise, obtained as a result of field tests, it allowed to choose the most rational and effective version of "floating" floor ‒ based on materials "Akuflex" and "Izolkap" (polystyrene concrete) ‒ scheme №11, the index of the reduced level of impact noise is Lnw = 52 dB. The arrangement of the structural and technological scheme of floor sound insulation №11 allows to reduce the level of initial impact noise in the room by 37.5%.

A field study of the relationship between sound insulation and noise annoyance, activity disturbance and wellbeing in multi-unit residences

Impact and airborne noise are often an issue for occupants in multi-unit residential buildings (MURBs). Despite minimum sound insulation requirements in building codes, occupants still complain about the impact and airborne noise which suggests that there is a lack of understanding of the relationship between sound insulation and occupants’ perceptions of their acoustic environment. To enhance existing knowledge on the relationship between sound insulation and occupants’ perception of noise, a field investigation was carried out in five Canadian MURBs with heavy-weight floor construction and concrete shear and steel stud walls. Airborne and impact sound insulation were measured, and surveys were conducted to assess subjective annoyance levels and effects on occupants’ various daily activities. The study found a significant correlation between airborne sound insulation and annoyance. However, there was no significant relationship between impact sound insulation and annoyance. The results showed no significant difference in impact noise annoyance between occupants in a building with high impact insulation (AIIC 62) compared to occupants in buildings with low impact insulation levels (AIIC 31–32). However, a significant correlation was found between impact sound insulation and reported effects of noise on work performance at home suggesting that disturbance of work or other activities might be a better indicator of occupants’ perception and acoustic comfort compared to annoyance ratings. In addition, the analysis revealed that occupants in suites located at the most exposed façade facing a major roadway report lower annoyance levels. The results indicate that the masking effects of outdoor or other noise sources should be considered when investigating occupants’ perception of impact and airborne noise.

Sound insulation performance of double membrane-type acoustic metamaterials combined with a Helmholtz resonator

As one of the representatives of acoustic metamaterials, the membrane-type acoustic metamaterial has excellent sound insulation performance due to its locally resonant features, which makes an extremely broad development prospect in many fields such as aerospace, ship and civil engineering. At the same time, sandwich structures are widely used because of their great mechanical properties. In this paper, we designed a sandwich structure of double membrane-type acoustic metamaterials combined with a Helmholtz resonator, a new structure is presented with both pleasant mechanical nature and admirable acoustic insulation at low frequency. Based on theoretical derivation we calculated the resonant frequencies and out-of-plane displacements of membrane-type acoustic metamaterials. The sound transmission loss, dynamic response and negative characteristics of the new structure are amply analyzed through numerical simulation, and the accuracy of the simulation is verified through experiments. It can be concluded that the average sound insulation performance of this new sandwich structure at 50 Hz–1600 Hz is 30% higher than the single-membrane type sandwich structure. At the same time, the sound insulation performance is improved by 24.8% compared with the double-membrane type sandwich structure which does not increase the cavity height. To sum up, this sound insulation performance of the structure is significantly higher than that of a single membrane-type acoustic metamaterial, with the possibility of flexible changes in cavity height, additional block arrangement form and membrane defect location from multiple angles, and a variety of configurations can be designed according to the actual engineering requirements of both lightweight, load-bearing and sound insulation requirements.

New Zealand is actively improving school acoustics with government-led initiatives

New Zealand's Ministry of Education is taking active steps to ensure that the country's 35,000+ classrooms are fit for purpose. Acoustics is a primary factor in central government's School Property Strategy 2030, which has informed three major initiatives to establish and implement sensible acoustic regulations. All three initiatives are underway. First is the Designing Quality Learning Spaces (DQLS) - Acoustics document, launched in December 2020. It sets out mandatory requirements for reverberation time (RT), background noise and sound insulation in new and refurbished learning spaces. Second is the Ngā Iti Kahurangi 'small and remote schools' programme. We are measuring RTs in 630 schools, assessing compliance with DQLS and adding absorption where necessary. The plan is to scale this programme up to include many more schools across the country. Third is the Internal Environmental Monitoring (IEM) programme. Sound levels (and other environmental factors like temperature, humidity and CO2) are continuously measured in a range of schools, and reviewed to inform improvements. These initiatives aim to provide quality learning environments for New Zealand children, and this paper sets out how they have been designed and implemented. Similar initiatives could be adopted by other countries to improve acoustic quality in their classrooms.

Resolving clashes between net-zero energy and acoustics engineering specifications, to enhance low-carbon building performance, regulatory compliance and future skills. Laws and standards comparison between Italy and UK

Under the CNR (Italy) and RSE (Scotland) joint scientific cooperation agreement, the present project deals with the development and enhancing understanding of the technical clashes and engineering solutions required to deliver net-zero outcomes across diverse construction systems both in new build and retrofit. This paper relates to the comparison between the two research groups about the acoustic and energy standards and low carbon measures in force in the both countries. The sound insulation requirements for residential buildings are mandatory in both Scotland and Italian building regulations. Sound insulation performance compliance is undertaken via on-site testing after completion of construction works whether new build or conversion/change of use. Importantly the specification for energy efficiency changes (and improvements) to the fabric of buildings often clash in terms of the material properties and performance functions for sound insulation. Thus, it is critically important for the specification changes in building materials for energy efficiency do not negatively impact noise and vibration sound insulation and vice versa. This can lead to non-compliance resulting in noise disturbance complaints by building occupants or loss of performance for energy efficiency. The paper characterises some of the regulatory factors, clashes in material outcomes and recommends the importance of multi-factor knowledge and understanding across building performance measures.

Descriptors of sound insulation of building structures in residential buildings in Ukraine and Europe

The object of the research is the descriptors (indices/parameters) of sound insulation of construction structures of residential buildings. The work presents a brief overview of modern generally accepted construction technologies in Eastern Europe. The most common sources of noise and the consequences of their impact on people's health and life have been studied. An analysis of the levels of airborne sound insulation indicators of building structures in European countries and Ukraine was carried out. Partitions for standard types of housing (private houses, townhouses, multi-story residential buildings) are considered. As a result, a great diversity of sound insulation requirements in different European countries was shown. And this leads to an imbalance and worsens the quality of connections in the construction sector, due to possible confusion and can cause certain problems in trade and exchange of experience. It is also shown that the difference between the numerical indicators of the sound insulation levels of air noise is not entirely appropriate within the EU, since the subjective indicators of the sound insulation of the population have approximately the same data. Comfortable conditions for people from different countries should be the same. Examples of descriptors of air noise sound insulation indicators of 35 European countries are given. Numerical norms of sound insulation levels of EU countries are detailed. General characteristics and differences between states are highlighted. The paper also examines the diversity of housing types and the relationship between detached, semi-detached (terrace/terraced) and multi-apartment buildings in many countries. This allows for some approximations to calculate the number of neighbors in these countries with adjoining walls and floors in attached housing. Having data on European countries, a conclusion was made with similar characteristics used in Ukraine. On the basis of the obtained data, the strengths and weaknesses of the Ukrainian noise protection regulations were determined, which consist in a small variety of modern types of housing, taken into account in the building regulations, and in a relatively low general level of requirements for sound insulation of building structures. Finally, the quality of life aspect of building occupants and the importance of good design, construction and control are discussed. We hope that the work gained will be used to achieve the goal of creating European-level housing. The already mentioned topic will be of interest to noise and sound insulation specialists, acoustic engineers, ecologists, urban planners and city planners.

Digital Design and Fabrication Strategy of a Hybrid Timber-Earth Floor Slab

The production of floor slabs with their high requirements for fire protection, thermal mass, and sound insulation is a central challenge in multi-storey timber construction. The research presented in this paper explores the possibilities of a timber-earth slab (T.E.S.) that can meet such high demands while being fully recyclable. T.E.S. comprises a hybrid structure, which aims to combine the strong tensile properties of wood with the beneficial properties of earth in terms of thermal mass, thermal activation capabilities, fire resistance, and sound insulation. It integrates a novel material technology capable of casting earth with low water content and combines it with robotic technology that enables the bespoke fabrication of a filigree wooden structure tailored to mechanically interlock with the earth infill. The proposed method makes it possible to place the earth infill in the lower part of the floor slab and thus expose it to the interior space, whereby its storage mass and component activation can be fully utilized. This paper presents the concept and design principles, initial findings on the system’s loadbearing behaviour, as well as the experimental validation of the novel fabrication process in 1:4 and 1:1-scale demonstrators, in which the general feasibility of the system in assessed. The paper finally discusses the proposed methods and results of the experiments and outlines further steps for transferring the system into building practice.

Shear behaviour of reinforced straw-bale plaster sheathed cold-formed steel-framed shear walls

The introduction of cold-formed thin-walled steel (CFS) framed systems into straw-bale construction is a new development construction. A CFS stud frame without blocking or strap-brace provides little in-plane shear stiffness, however it can provide lateral support for the thin and low-reinforcement sheathing through self-tapping screw anchorage, allowing the sheathing to subject to shear failure rather than buckling failure. Straw-bales with different thicknesses can satisfy different requirements for heat transfer and sound insulation. Since straw-bales are reliably bonded to the sheathing, the straw-bales can provide lateral support for the thin sheathing and can also effectively slow down the decline of the shear strength after the sheathing cracks. Moreover, the anchorage slip and the shear deformation of the sheathing material are the major factors affecting shear stiffness. The theory presented in this paper predicts the shear deformation response of the reinforced straw-bale plaster sheathed CFS framed shear wall specimen. The behaviour of the self-tapping screw anchorage was defined using power curve to predict the wall deformation due to anchorage slip. The deformation caused by shear in the sheathing material was estimated using refined softened truss model, which was based on the mechanical equilibrium condition, strain compatibility condition, and the constitutive relationship of softened cement mortar and mesh wire embedded in cement mortar. Comparing the theoretical results with the experimental data, the two were in good agreement. The shear strength of different configurations of reinforced straw-bale walls described in the literature were estimated, which proved the applicability of the theory. • Introduction of cold-formed thin-walled steel (CFS) framed system into straw-bale construction. • Estimation of the two major factors affecting the wall shear stiffness. • Validation of the predicted results according to experimental data. • Prediction for the shear strength of reinforced plaster straw-bale walls with different configurations.

Timber hollow-box floors: Sound insulation measurement results and analysis

We performed measurements of the sound reduction index and impact sound pressure level for a range of lightweight floating floors installed on a hollow-box timber floor. The measurements were performed in the laboratory according to the relevant standards. We tested different configurations, varying the cavity filling of the bare floor and the assembly of the lightweight floating floor. We tested floating floors with a continuous elastic layer with high and low dynamic stiffness, floating floors on elastic load-bearing units and a basic vinyl covering of the bare floor. The results show that a wide range of sound insulation can be achieved, making the hollow-box floor elements suitable for different purposes. Best performance is achieved with elastic load-bearing units installed on the bare floor with gravel in the cavity. Detailed analysis of the achievable sound insulation improvement is also given. This shows that reasonably reliable predictions can be made using well-known equations from the literature. Key parameters are the resonance frequency of the system, determined by the mass per unit area of the bare floor and of the floating floor as well as the dynamic stiffness of the resilient layer, and the configuration of the elastic layer. The results and the highlighted prediction equation offer a solid basis to help develop solutions to meet different sound insulation requirements and make the hollow-box floor elements suitable for urban buildings with several purposes, ranging from office/commercial to educational and residential.

FIELD TESTS OF THE EXPERIMENTAL CONSTRUCTIVE SCHEMES OF SOUND INSULATION OF THE FLOOR

The dynamic development of urbanization in Ukraine, as well as throughout the world, only increases the number of noise sources that disturb people. And this cannot be ignored, because insufficient sound insulation in an apartment threatens people with neuroses, changes in biorhythms, disorders of the digestive system, headache, memory impairment, problems associated with the perception of color. Therefore, you need to pay maximum attention to the sound insulation of premises during the construction of residential buildings. One of the main disadvantages of monolithic reinforced concrete multi-story buildings is noise. Penetrating into the apartment, he becomes the cause of irritation, an obstacle to sleep or concentrated work. It's no secret that high-quality soundproofing of premises plays an important role in our life and is necessary for our comfortable well-being. This article is devoted to solving an important issue of soundproofing floors in monolithic reinforced concrete multi-story residential buildings, namely from impact noise. The article discusses structural and technological schemes for sound insulation of a floor of three types, using various materials and their combinations to achieve the regulatory requirements for sound insulation from impact noise. When choosing the most rational structural and technological scheme, the results of a comparative analysis of organizational and technological indicators for the device of soundproofing the floor were used, as well as indicators of the reduced impact noise obtained as a result of full-scale tests. Full-scale tests were carried out in houses under construction. The technology for performing each type of floor will depend on the chosen structural and technological scheme, and in the future, the comfort of the residents of the apartment. Comparison of the structural and technological schemes in the future will allow to study and develop a modern and highly efficient structural and technological scheme of the floor sound insulation structure.

Investigation of Warp and Weft Knitted Fabric Acoustic Structures Derived from Garment Waste

The mechanical performance of knitted fabric was significantly affected by loop density and geometries. Knitted fabric composites occupy a special position in the field of engineering materials because of their easy to form complex components and high impact energy absorption. But Knitted fabric composites have low in-plane tensile strength because the yarns are in a loop structure in the materials. Sound insulation requirements in automobiles, manufacturing environments, and equipment, generating higher sound pressure drive the need to develop more efficient and economical ways of producing sound absorption materials. The knitted fabric based acoustic materials were produced from cut wastes from different garment industries for their sound absorption property test as per the method described in ASTM E 1050. The acoustic performance of knitted fabrics was measured by independent tube methods for sound waves of 1000-6000 Hz. It is observed that the knitted fabrics acoustic materials prepared from waste materials showed high sound absorption than woven fabrics made from the same synthetic fibers. Moreover, the test revealed that blended knitted fabric had a better sound absorption property.

Acoustic retrofit strategies of windows in facades of residential buildings: Requirements and recommendations to reduce exposure to environmental noise

Achieving an adequate indoor acoustic comfort environment is one of the main priorities to avoid adverse effects caused by noise. Façades are the constructive elements most likely to be retrofitted due to their delimiting function between indoor and outdoor space. This study compares the acoustic façade requirements established for new and existing buildings in current national building regulations. The assessment of regulations and the analysis of a comparison model, examining different techniques for improving sound insulation, conclude that on a global scale there is a lack of consensus on external noise insulation and acoustic requirements worldwide. It is not possible to merely summarize all requirements into a single number as the sound insulation required depends on the performance of the building element, the outdoor noise level or the indoor noise level. Therefore, there is an in-depth discussion on the harmonization of external sound insulation requirements in acoustic regulations. This study also analyses façade wall solutions of existing housing stock and compliance with current regulations, with results showing that upgrading interventions focused on windows can be sufficient to propose suitable constructive systems in compliance with requirements established worldwide when external noise amounts to 60 dB(A) measured 2 m from the façade.

ОЦІНКА ЕФЕКТИВНОСТІ ЕКСПЕРИМЕНТАЛЬНИХ КОНСТРУКТИВНО-ТЕХНОЛОГІЧНИХ СХЕМ ТЕПЛО- ТА ЗВУКОІЗОЛЯЦІЇ БУДИНКІВ

This work is devoted to solving an important issue regarding the sound insulation of floors in residential buildings, namely from impact noise. The article considers the structural and technological schemes of floor sound insulation of three types, using different materials to achieve regulatory requirements for sound insulation from impact noise. Field tests were conducted in the building under construction. The technology of execution of each type of a floor, and in the future and comfort of inhabitants of the apartment will depend on the chosen constructive-technological scheme. Comparison of structural and technological schemes in the future will allow to investigate and develop a modern and highly effective structural and technological scheme of sound insulation of the floor. It was determined that the most effective structural and technological solution for the construction of sound insulation of the floor, and one that meets regulatory requirements, is the design - Type 1, based on materials "Izolkap Fine" and "Akuflex".

Application of Computer-based Simulation Analysis in Green Architecture Design

Through simulation calculation of sunshine, wind field and noise in Lize Financial Business District, it is suggested that natural light should be introduced into the room to make up for the influence of insufficient sunshine, or lighting fixtures with low energy consumption should be selected for artificial lighting., land owners should design solar photovoltaic power generation properly, an open structure should be adopted at the bottom of the annex building to guide the natural wind and enhance the ventilation. According to the sound insulation requirements at different heights of buildings and those in different facade directions at the same height, sound-proof windows made of different materials with different performance should be selected to ensure the maximum use of natural lighting and ventilation, energy conservation and environmental optimization of buildings in the region, meeting the requirements of people for indoor and outdoor comfort.

Thermal behavior of external-insulated cold-formed steel non-load-bearing walls exposed to different fire conditions

An external-insulated cold-formed steel (CFS) wall is a potential configuration that overcomes the disadvantage of cavity insulation in the fire performance of such walls and can meet the sound and thermal insulation requirements for building structures by increasing the thickness of insulation material. This paper conducted eight mid-scale non-load-bearing fire experiments on external-insulated wall specimens. Four different fire conditions were tested, including ISO 834 fire, external fire, hydrocarbon fire and a typical realistic design fire. A quasi-steady heat transfer state was identified at the final stage of external fire exposure. The effect of substituting the cavity insulation with external insulation on the fire performance is discussed by comparison with the previous fire experiments on cavity-insulated CFS walls. The results show that external insulation is a more reasonable configuration than cavity insulation for improving the fire resistance of CFS walls. In addition, two types of stud buckling, which include the local buckling of the whole stud section and local buckling of stud hot flange and adjacent web, were identified for non-load-bearing walls in fire, and the corresponding cause and conditions were described. In addition, to achieve high efficiency in the thermal performance modeling of CFS walls in fire, a quick and simplified calculation method was developed to get the temperature profile of steel frame based on a one-dimensional finite difference method. Moreover, an unexposed surface temperature of 900 °C was recommended as the criterion to predict the falling-off of the fire-side face-layer gypsum plasterboards of CFS walls in the heat transfer modeling.

Acoustical retrofit of existing residential buildings: Requirements and recommendations for sound insulation between dwellings in Europe and other countries worldwide

Exposure to noise is proven to have important repercussions on human comfort and health conditions. In recent decades, efforts to increase awareness among users have focused on highlighting the benefits of an appropriate acoustic indoor environment. In addition, given the significant increase in complaints about noise, the control, reduction, and limitation of sound transmission have become important issues to be considered in acoustic retrofit work in buildings. Much of the housing stock was built in a period characterized by the limitation or absence of standards, and renovation interventions should be geared towards existing buildings. However, despite the major potential to improve quality of life, only a handful of countries consider old buildings in their national Building Codes and regulations. The main aim of this work is to develop a comparative study of the acoustic requirements for indoor sound insulation between dwellings of existing buildings established in current building regulations around the world. The analysis of the documents concludes that the usual difference between requirements for new and existing buildings is 5 dB, both for airborne sound insulation and impact sound insulation. To this end, this paper provides the basis for discussion regarding future cooperation for the optimization of acoustic regulations for old buildings.