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To meet users’ needs for the building comfort, this article researched the impact sound insulation performance of timber floor structure under different conditions. The research has been done on a common floor covering and three floating floor coverings (composed of Portuguese cork board, a kind of improved graphite polystyrene sound insulation board (BGL) and expanded polypropylene sound insulation board (EPP) respectively) in the same bedroom in a two-story light-weight timber structure. The tapping machine excitation and daily behavior excitation test methods have been used, and the field tests on the impact sound insulation of the floors under conditions that doors and windows are closed and doors and windows are opened have been validated. Based on the test result, the sound insulation effects has been analyzed; law of the sound pressure distribution of the noise sources and the change of sound pressure with frequency has been validated; the frequency characteristics of the noise sources has been summarized; and the optimization measures of sound insulation has been proposed. The main conclusions show that: the impact sound insulation effect of the floating floor is more significant than that of the ordinary floor, BGL floor has the highest impact sound pressure level improvement; the insulated sound pressure of the floating floors is 10–20 times more than that of the ordinary floor in condition of tapping machine; With the increase of the frequency, the measured impact pressure level of the floor decreases continuously, and the decrement of the impact sound of the floor increases; in the frequency range of 80-8000 Hz, the sound pressure distribution of the floating floor is lower than that of the ordinary floorsound pressure. The impact sound insulation test is expected to provide a useful reference for improving the sound insulation performance of the timber floor structure, and has high engineering application value for improving living comfort.

With an increasing demand for quieter residential environments, impact sound insulation for floating floors is gaining importance. However, existing methods for estimating the performance of heavy ...

We investigated the effects of a floating floor on heavy impact sound in the low-frequency range below 100 Hz with focus on the structural vibration. To verify the mechanism of amplifying the floor impact sound, field measurements were conducted before and after the installation of a floating floor while the other conditions were kept constant. Field tests were performed on five apartment units where the material properties of the resilient materials in the floating floors differed. Slab accelerations and sound pressure levels were measured simultaneously. The test results indicated that the low-frequency responses of slab acceleration and the corresponding heavy impact sounds were amplified in all apartment units after the installation of the floating floor, while high-frequency responses greater than 100 Hz were significantly reduced. The amplified responses were attributed to the interactions between the mortar plate (floating floor) and concrete slab, which were connected by a resilient material layer. The degree of amplification tended to increase as the loss factor of the resilient material decreased while the amplified frequency range was determined by the stiffness of the resilient material layer. The result was numerically verified using a simplified mass-spring model.

The sound insulation performance of extruded panels used in railway vehicles is critical to control the interior noise, especially in the case of floor panels. To reduce the mass of floating floors and increase its sound insulation performance, a lightweight design instruction approach has been proposed based on the vibration response of each component of the floating floor structures. The total height, length, thickness of the top layer, thickness of the ribs, and thickness of the bottom layer in the typical cross section of the exterior floor are used as variables; the mass of the typical cross section and the averaged sound transmission loss (STL) results in 1/3 octave bands centred from 400 to 3150 Hz are used as the optimisation targets; the optimal result of the smallest mass and the largest averaged STL are achieved in commercial software VA One and Isight. The effect of this optimisation scheme on the sound insulation performance of the floating floor is analysed based on the verified STL prediction model. After this optimisation, the results indicate that the mass of the exterior floor structure is reduced by 15.2% compared with the original exterior floor structure, and the averaged STL in 1/3 octave bands centred from 400 to 3150 Hz and the weighted STL of the floating floor are increased by 0.8 dB and 1 dB, respectively.

An effective way to reduce impact sound in buildings is to install a floating floor consisting of a floating slab separated from the structural slab by a continuous viscoelastic layer. Although a considerable amount of work has been reported on nanomaterials in the past decades, the impact sound reduction performance of polymer/clay nanocomposites has not been specifically addressed in the literature. In this paper, we report the synthesis and characterization of a nanocomposite made of thermoplastic polyurethane (TPU) with laponite clay filler and its potential use for reducing impact sound in floating floor technology. Samples were prepared with laponite content ranged between 0.5 and 10 wt% for each nanocomposite synthesized using a solvent solution mixing process. The characterization of the nanocomposites confirmed that the clay content in the TPU matrix has significant impact on the viscoelastic properties. In particular, the incorporation of 5–10 wt% laponite clay in the TPU matrix increased mechanical damping and reduced dynamic stiffness as compared to the pristine TPU. The experimental results were compared with a constitutive model that extends the Cremer-Ver model. The results predicted a considerable improvement of the impact sound insulation at the resonance frequency when the nanocomposite is used as a continuous viscoelastic layer supporting the floating slab. These results were attained without significantly increasing the total weight of the floating layer.

Considering the impact noise as a major social issue in many countries, extensive work have been developed aimed at reducing the noise level in dwellings. Laboratory tests were carried out to investigate the acoustic performance of same constructive proposals, arranged to reduce the impact sound transmission. According to this study, acoustic performance of both types of floors differs significantly, with a difference of up to four times that of the effect of floating floor system on a homogeneous floor in some cases. The conclusions can help to determine the proposal of best suitable constructive solutions in accordance with legal regulations.

In today’s apartment houses, adoption of floating floor has vastly improved structure-borne floor impact noise by isolating vibration components well in excess of the major structural vibration resonant frequencies. For 20–200 Hz frequency region encompassing major structural vibratory and room acoustic modes, however, impact noise attenuation is much harder to achieve, and the problem can be exacerbated for small rooms where these modes are sparsely placed in audible frequency range. Experimental and numerical investigation of the effect of structural vibration and room acoustics on impact noise for the frequency region is undertaken. Structural vibration modes of the room with floating floor correlate well with the spectral characteristics of the impact noise, with various structural parts making different contributions in the frequency domain. For the low end of the impact noise spectrum, low density of high-energy axial room acoustic modes arising from small room size causes sound field in the room to show notable variation with measurement locations. For the mock-up typical of a small-sized living room considered in the present study, one of the vibrational mode of floor slab excites an overlapping fundamental room acoustic mode that further amplifies the impact noise. A room design that avoids overlapping of major structural and acoustic resonance modes at low end of the audible spectrum could be crucial in abating an echo commonly encountered in bare apartment rooms.

Impact noise is a major sound transmission problem in concrete buildings that severely affects the quality of life of residents. The impact insulation of a concrete floor can be improved by the use of floating floor constructions. Commonly, a floating floor consists of an upper panel and a resilient layer , which is in turn laid on the concrete structural slab. Lightweight laminate flooring has become one of the most common floor surfaces in many countries. It is not only used in new dwellings and modern concrete multistorey buildings, but also to replace allergy-causing carpeted floors. However, the improvement in impact sound insulation of lightweight laminated floors has not received much attention. This study aims to report the improvement in impact sound insulation of a typical laminated floor resting on different commercially available thin underlayment materials above a concrete structural slab. Although all the floating floor combinations exhibited different impact sound insulation performance as a function of frequency, the standardized single number ratings described in ISO 717-2 were almost identical. However, environmentally friendly fibrous continuous layers tested in this study reported better impacting sound performance compared with polymeric materials. The force transmissibility-based theory is applied and revised to properly predict the experimental results for this type of floating floor well: an empirical stiffness-dependent formula is derived. In general, the experimental results of the improvement of impact sound insulation are in close agreement with the results obtained with this empirical formula.

In Korean residential buildings, floor impact sounds were reduced over the past few decades mainly through a floating floor system. However, ceiling constructions for impact sound reduction have not been applied actively because of a lack of useful information. This study focuses on the effects of wall-to-wall supported ceilings (WSC), which are designed with construction discontinuities between concrete slabs and ceilings, and the damping caused by porous absorbers for impact sound insulation. To examine the impact sound insulation according to ceiling conditions, measurements were performed in 25 floor–ceiling assemblies. The results indicate that ceiling treatment is mostly useful in reducing the floor impact sound. The floor impact sound owing to the WSC decreased by 2–7 dB and 2–8 dB in terms of the single number quantity for the tapping machine and rubber balls, respectively, compared with representative existing housing constructions wherein ceilings were attached on wooden sticks. Furthermore, the reduction effect of the WSC appeared to be more profound when it was applied to the floor–ceiling assembly with poor impact sound insulation. Thus, the WSC can be used to enhance the impact of sound insulation of existing housings without major repairs of floor structural layers.

The primary aim of the presented research is to introduce a new approach based on the probabilistic analysis, which provides an accurate prediction for the improvement of the impact sound pressure level of a floating floor considering the uncertainty of material parameters. The theoretical background of the novel method was provided. It embraces two theorems describing the propagation of uncertainty of a random variables function. The introduced technique leads to the determination of the probability density function of a considered output parameter based on the joint distribution of an input random vector. Secondly, the algorithm was applied to investigate the insulation improvement of an exemplary floating floor. The considered construction was composed of extruded polystyrene as a resilient material and cement screed as a floating slab. The dynamic stiffness and the loss factor of the resilient layer and the density of cement screed served as input variable parameters with Gaussian distributions. The probabilistic analysis was based on two models providing the insulation improvement of a floating floor, e.g., Cremer-Ver formula and the recently proposed transmissibility model. Finally, the accuracy of the described methodology was verified by comparing it to the results obtained by Monte Carlo, performing 106 simulations. Additionally, we introduced a simplified model using the linearization of the Cremer-Ver relation, which can be applied to determine the probability density of sound insulation improvement for floating floor composed of XPS and cement screed in a simple and efficient way.

Floating floors have a high potential for reducing disturbance by impact noises in dwellings, since it greatly reduces the vibrations transmission through structures. The acoustical performance of a floating floor is quantified in terms of improvement of impact sound insulation Δ L. The improvement of impact sound insulation of a floating floor is a key parameter for the calculation of structure-borne sound insulation in buildings. Indeed, once Δ L is known, it is possible to evaluate the impact sound insulation, in in situ conditions, for several base floors of different building technologies and materials. Δ L can be directly determined on the basis of standard laboratory measurements, but it can be also estimated from elastic and inertial properties of involved materials, such as stiffness and mass. In this paper a constitutive model for the estimation of floating floors improvement of impact sound insulation is presented. As it will be shown, the constitutive model proposed based on force transmissibility theory, allows to accurately estimate the acoustical behavior of a floating floor, as a function of frequency, with a simple single function. Theoretical assumptions, experimental evidences and comparisons with previous computational models (e.g., Cremer-Ver model) allow to confirm both validity and effectiveness of the proposed model.

Structure-borne noise and vibration from weight drops and fitness activities are an ever-increasing source of disturbance within multi-residential, hospitality, and multi-tenant commercial buildings. High-mass floating floors supported on low-resonant frequency isolators have been used with good effect to reduce impact noise and vibration, but commonly require expensive supplemental supports or structural stiffening to be implemented properly. Common light-touch fitness solutions feature continuous or interlocking resilient surface treatment. This approach is often ineffectual at high-energy impact fitness areas and the pursuit of soft surface solutions to achieve greater dissipation of impact energy can create an unstable surface for weightlifting. An alternate approach to reducing structure-borne noise exists which focuses on dissipating the impact energy through constrained layer damping in conjunction with low-resonant frequency isolators. Research and development testing shows that an engineered all-dry lightweight fitness floating floor is capable of achieving equal or greater impact insulation performance than a high-mass concrete floating floor and significantly better performance than light-touch resilient surface treatment. A review of the testing and development process and underlying principles will be reviewed to illuminate the mechanisms at work in the next generation of fitness floating floors.

Impact noise is increasingly becoming an important issue both in terms of technologies for its reduction and in terms of its perception inside buildings. In fact, a high level of noise clearly affects indoor comfort and liveability of confined spaces. For this reason, this study focuses on the influence which the screed static load has over time on the resilient material of a floating floor and on its final performance. Five different types of resilient materials have been tested for five years and the results are analysed in terms of material type, surface contact and thickness variation, dynamic stiffness measured on 8 different time steps and its application on 6 different bare floors. Obtained parameters values are therefore studied in terms of perceived comfort and compliance with 31 European countries regulations limits. Results clearly show that time has a paramount influence on all types of resilient materials (with the exception of one) in all configurations and that complete floor selection, in time, can greatly change perceived indoor living comfort and compliance with the limits imposed by laws.

With the development of rail transit and the shortage of land utilization, properties above and near metro depots emerge in Chinese major metropolises. Whether the railway-induced vibration will bring discomfort to occupants or malfunction to precise devices is always the concern of stakeholders, designers, occupants, and researchers. In general, there are three main facets to control the train-induced vibrations: from the vibration source, from the wave transmission path, and from the building structure. General vibration mitigation methods include the rubber float-slab track, continuous-wave barrier systems, non-continuous wave barrier systems, wave impedance block, blocking floor, floating floor, etc. This paper mainly focuses on the effectiveness of the open trench in reducing train-induced vibration based on a field test conducted at the throat area of a metro depot of Guangzhou. The results reveal that (a) the vibration attenuation in curve-line segment of the throat area is more than that in straight-line segment, as there being 28–36 dB attenuation in curve-line segment and 22–24 dB attenuation in straight-line segment; (b) higher-frequency components (above 50 Hz) attenuate faster than lower ones and the propagation distance of the former is shorter; (c) the peak frequency induced by trains operating at metro depots lies in 31.5–40 Hz; (d) the effectiveness of the open trench in mitigating horizontal vibration is better than that in reducing vertical vibration. Some suggestions on designing the open trench to reduce railway-induced vibration are also proposed.

Sound insulation performance of floor is the basic functional requirements of green buildings. However, without special sound insulation design and construction processing, the requirements of sound insulation design indexes are difficult to be met in reality. As a component of space separation, the floor should be emphasized, especially the impact sound insulation performance of the floor. In this paper, the reinforced concrete residential floor is taken as the reference, and the influence factors on the impact sound insulation performance of floor are considered, including type, thickness, mass density and dynamic stiffness of elastic material, and the quality and thickness of floating plate. Besides, construction methods for different series of floating floor are presented, and the impact sound insulation change is studied through theoretical and experimental analysis. This study provides technical support and case experience for the sound insulation and noise reduction design of the floor, so as to improve the sound insulation performance of the floor.

Acoustic performance is a building and users requirement, sometimes neglected, which commonly causes discomfort to the neighborhood. Subfloors with acoustic insulation properties are an alternative to minimize this problem. They are made with different materials types, including industrial wastes, reducing the Construction Industry impact, making it more sustainable. This research aims at assessing, experimentally, different subfloor mortars, with lightweight aggregates, to reduce impact sound, produced from the replacement of different contents of natural aggregate for exfoliated vermiculite and chrome sawdust (waste from tanning industries), in comparison with an industrialized mortar commercialized with acoustic isolation characteristics. The mortars were characterized by national standards, their dynamic stiffness was measured (according to ISO 9052-1) and used to estimate the sound reduction for impact noise (as stated by ISO 12354). Mortars with aggregate substitutions, including the wastes in higher substitution contents, have the potential to become an alternative for impact noises insulation in floating floor systems.

Floor impact sound is one noise in apartment houses that cannot be avoided. In order to reduce floor impact sound, a floating floor system using resilient materials has been generally applied. Floor impact sound insulation performance of the floating floor system is dependent on the physical property (dynamic stiffness) of resilient materials. This study investigated the effect of temperature changes on resilient materials used in the floating floor system and on dynamic stiffness. Ethylene vinyl acetate (EVA) and expanded polystyrene (EPS) were used as resilient materials, and dynamic stiffness was measured during three stages of temperature change condition. The measurement result showed that as the temperature decreased, dynamic stiffness also increased. This study also analyzed the effect of changes in outdoor temperature on the heavyweight impact sound level with respect to concrete buildings with wall slabs. The floor impact sound level tended to increase during the winter season, when the outdoor temperature was low.

The approach used to calculate structure surface vibration velocity and sound pressure level (SPL) is provided. Then structural vibration model and panels acoustic contribution are combined to investigate sound radiation from a vibrating structure. As for the shipboard cabin where the mariners work with high level requirement of the SPL, it’s necessary to build the boundary element model of shipboard cabin by obtaining the structural mode information and finding out characteristics of vibration velocity. Considering the effect of thin-shell-structure consoles and switchboards, the acoustic field inside the shipboard cabin and the panel contribution to the cabin are analyzed. The peak frequencies in the sound pressure spectrum at the field points and their corresponding panels with larger contributions to the cabin are found. Based on the modal shape analysis, damping is adopted to inhibit the predominant modes. In front of the console and the switchboard where the engineer on watch operate, at the height of one’s head with sitting posture and standing posture, four field points are laid out respectively. Then, the most obvious peak frequency is picked out as the frequency of attention. Vibration reducing measures like laying damping coatings and modular floating floors and so on are adopted to reduce the noise radiation of the plate in the ship cabin. Through the deck vibration transmission experiment, the damping performance of the modular floating floor is ascertained. A comprehensive assessment of the noise label in the cabin is needed to ensure that the sound pressure level meet the relevant requirements of the ship general rules.

Building multi-dwelling units is one of the practical engineering solutions to housing shortage in urban areas with high population density. However, noise from upstairs is a major issue. The use of resilient materials in floating floor structures is recognized as an effective method to reduce such noise. In general, soft materials are considered as better resilient materials due to their superior performance in impact sound reduction. However, it is often overlooked that the sound reduction performance of soft resilient materials is susceptible to being degraded over time when subjected to a long-term load. In this study, the long-term performance of eight resilient materials is evaluated by monitoring their dynamic stiffness for 270 days under the two sustained load conditions: 250 N and 500 N. According to the experimental study, the dynamic stiffness increases consistently with loading time for all resilient materials. This leads to a decrease in the sound reduction performance. More rapid reduction in the dynamic stiffness and hence in the sound reduction performance is observed when a larger sustained load is applied. A greater decrease in the sound reduction performance is found in soft resilient materials.

This study focuses on the compression behavior of hemp shiv layers for bio-based floating floor applications. An experimental campaign was performed to measure the instantaneous and creep behavior of different hemp shiv. The effect of humidity was also taken into account. A model was developed to assess both instantaneous and creep behavior of the shiv layer. The model validity ranges from a compressive stress of 0 to 5 kPa and with moisture ratio up to 20% in mass. It was used to define the maximum acceptable initial height of the shiv layer to guarantee a limited long-term deformation. These modeling and experiments lead to recommendations for application.

The dynamic stiffness of underlays is a required quantity to predict the reduction of impact and airborne noise transmitted through floating floors. The measurement of the dynamic stiffness is standardized in ISO 9052–1 using a floating floor section of 200 mm edge length. If open pore insulating materials are used for the underlay, the air flow and its flow resistivity have a significant impact on the dynamic stiffness. The standard ISO 9052–1 therefore calculates the dynamic stiffness based on three distinct intervals of the flow resistivity. This contribution analyses and discusses the mathematical origin and practical consequences of these three standardized intervals and proposes an improvement for a revision of the standard. The current physical model is expanded to examine if the results, that are gained from the geometrically reduced systems of the standard, can be transferred to room sized systems.

This research concerns the study of composite boards made from polymer-based materials that include rice husk and recycled rubber granules, to see if they can mitigate vibrations and improve the impact sound insulation of floor solutions in buildings. The influence of the composite mix, mass density and board thickness on the overall performance was studied experimentally. First, the composites were studied under static compressive loading. Then, the behaviour under dynamic loads was evaluated through transmissibility tests for frequencies ranging from 20 to 200 Hz with five different static loading scenarios, from which the dynamic transfer stiffness and transmissibility curves were determined. The ability of the proposed composite boards to improve the impact sound insulation of floors was also assessed experimentally, in adjacent vertical acoustic chambers. The composite boards were tested as the top layer of the system and as part of a floating floor. For the latter, a thin slab was built above the tested specimen. The results indicate that composites produced from rice husk and recycled rubber granules can help to mitigate vibration in building solutions. Thicker samples whose rubber content was higher and apparent density lower showed higher vibration isolation capacity for a wide range of frequencies. Moreover, it was found that rice husk and rubber boards were able to improve the impact sound insulation of floor solutions. Composite boards with higher rubber content were found to perform better as floor coatings.

Floating floor increases the impact sound insulation of a load bearing concrete slab but very little is known about the subjective perception of impact sounds transmitted through floating floors. A psychoacoustic experiment was conducted to answer three research questions: 1. Is there a subjective benefit to use a floating floor instead of a non-floating floor with natural impact sounds? 2. Do the standardized single-number quantities of impact sound insulation rank the floors in the same order as subjective ranking does? 3. Does the resonance frequency of the floating floor play a role in subjective perception? Four floating floors and two non-floating floors were built in a laboratory where the impact sound insulation was tested using tapping machine and rubber ball. Four natural sound types (basketball bouncing, chair moving, walking with shoes, walking with socks) were presented to the floors and recorded in the furnished room underneath. The recorded sounds were played to 30 participants who rated their annoyance. The answers to the research questions became the following. 1. Floating floor was beneficial over non-floating floor for three sound types out of four. 2. Single-number quantities did not always rank the floors according to the same order as the psychoacoustic experiment did. 3. Lower resonance frequency predicted lower annoyance for most sound types. It seems that the current objective methods of rating the impact sound insulation are not sufficiently predicting the perceived performance of floors. Our results benefit the development of floor constructions and measurement standards.

In this paper, the sound insulation performance of the floating floor is studied from the perspective of its structural application. The field test shows that the sound insulation improvement value of the dry laying method is higher than that of the wet sticking method. At the same time, the influence of the construction technology of the floating floor on the load and net height of the building structure is summarized and compared. Finally, the weighted standardized impact sound pressure level of the field test is higher than the normalized impact sound pressure level measured in the laboratory This universal phenomenon is analyzed. This paper puts forward the construction technology of dry laying method of floating floor with sound insulation mat, which can provide reference for the construction of sound insulation mat laying on reinforced concrete floor and the design of building structure.

With the increasing demands for indoor comfort, the sound insulation issues of buildings should not be ignored. The impact sound of floors is the main source of noise between rooms. In this study, impact sound insulation tests were performed on one cross laminated timber (CLT) floor and one timber-concrete composite (TCC) floor to investigate the impact sound insulation performance. Since the sound insulation performance of bare floors is poor, effective sound insulation improvement schemes were proposed, including three kinds of solutions of floating floor and two kinds of solutions of suspended ceiling for TCC floor and CLT floor. In addition, an additional optimization solution of floating floor was also presented for CLT floor. The impact sound insulation performance of two floors with different solutions in full frequency range was compared and analyzed. The test results showed that adding floating floor and suspended ceiling can improve the impact sound insulation performance of floors to a certain degree, and the latter is more effective. The experimental and analytical results could provide a reference for improving the sound insulation of residential floors.