Heavy-weight Floor Impact Research Articles

Measurement and prediction of heavy-weight floor impact sound

Measurement and prediction of heavy-weight floor impact sound

타공형 석고보드 천장적용에 따른 중량충격음 저감 효과분석

As the number of old apartments increases, a method that reduces heavy weight floor impact sound during remodeling or repair work needs to be developed. Generally, apartment ceilings are constructed using gypsum boards with an air layer approximately 170 mm to 200 mm from the bottom slab. This air layer causes amplification of heavy impact sound in the 63 Hz ~ 125 Hz frequency band. In this study, to reduce amplification of sound, a ceiling structure composed of sound-absorbing material and perforated gypsum boards is used. For optimal design, the sound-absorbing performance of ceiling constructs are tested. Moreover, the selected ceiling structure is constructed for a laboratory similar to an apartment house to verify heavy-weight impact sound insulation performance. The experimental results show that sound was reduced by 2.6 dB at 63 Hz and by 0.7 dB at 125 Hz. For a rubber ball, it was reduced by 1.8 dB at 63 Hz and by 1.6 dB at 125 Hz. Single number quantity(LSUBi,Fmax,AW/SUB) is reduced bang machine by 1 dB and rubber ball by 2 dB.

Experimental Evaluation of Reinforced Concrete Slab Reinforced by Composite Mortar in terms of Flexural Behavior and Floor Impact Noise Evaluation

ABSTRACT A total of 13 ferroconcrete slab specimens reinforced by composite mortar were used to conduct a strength performance evaluation with the types of reinforcement and the diameter of wire meshes as its parameters to determine failure modes, ductility and stiffness. A total of six floor impact noise tests based on KS F 2810-2:2012 were performed at the construction site of H apartment complex, which had just completed frame construction. The study used Ethylene-Vinyl Acetate Copolymer (EVA), Expanded Polystyrene (EPS), and Polypropylene (PP) as the reinforcement materials effective against floor impact noise, and employed the grid-shaped steel wire meshes for improving strength performance. The test results showed that in the case of the reinforced slab specimens, there was no detachment of reinforcement materials like the wire meshes and composite mortar thanks to the bonding force of anchor bolts and composite mortar. Under the maximum strength, the EVA-reinforced slab specimen was the most effective by improving the heavyweight floor impact noise by 23% and the lightweight floor impact noise by 12%.

Evaluation of the Floor Impact Sound Insulation Performance of a Voided Slab System Applied to a High-Rise Commercial Residential-Complex Building

Multi-unit dwellings, such as apartment housing, town houses, and flats, are some of the most common housing types in Korea, as well as in other countries. Such multi-unit dwellings are considered an effective means to overcome the housing problems of high-density population in urban areas, owing to their high efficiency of land utilisation. However, interlayer noise complaints, such as footsteps or dragging items in apartment housing, are an inevitable problem in apartment dwelling conditions, because each household in an apartment shares walls and ceilings with other households. This paper presents the results acquired from the field test of the floor impact sound insulation performance of a voided slab system as applied to a commercial residential-complex building in South Korea. The results have shown that adopting the voided slab system for a commercial residential-complex building increased floor impact sound insulation performance. The test results show that the sound insulation performance of the voided slab system applied in the building for lightweight and heavyweight floor impact sound reached (47 and 41) dB, respectively. Based on the results of the field tests, it is expected that the application of the voided slab systems to the slabs of the apartment dwellings would be effective, and offer outstanding sound insulation performance. Moreover, it is expected that the floor impact sound insulation performance would be further improved, if the floor finishing materials, such as carpet or other types of flooring material, would first be installed onto the floor.

EPS 완충재의 동탄성계수 및 두께에 따른 중량 바닥충격음 레벨 분석

This study investigated the relationship between dynamic stiffness, thickness, and heavy-weight floor-impact sound level for EPS resilient materials with 10 MN/m3 ~ 30 MN/m3 dynamic stiffness and 10 mm ~ 30 mm thickness. As a result, the single-number quantity (SNQ) with a bang machine was 52 dB ~ 57 dB, SNQ with rubber ball at 1.0 m height was 48 dB ~ 52 dB, and SNQ with rubber ball at 0.3 m was 43 dB ~ 48 dB. The relationship between dynamic stiffness and SNQ with bang machine was a negative correlation, and that with a rubber ball was a positive correlation. The floor impact sound level at 63 Hz showed a negative correlation with dynamic stiffness, and those at 125 Hz and 250 Hz showed positive correlations for all impact sources. The thickness of EPS resilient materials was negatively correlated with floor-impact sound level over 125 Hz for all impact sources. In addition, a design method of EPS resilient materials is discussed using a contour map of floor-impact sound level in terms of thickness and dynamic stiffness.

Effects of sound absorbent gypsum board in the ceiling on low-frequency heavyweight floor impact sound

Effects of sound absorbent gypsum board in the ceiling on low-frequency heavyweight floor impact sound

Flanking floor impact sound insulation in cross laminated timber model building for experiment

The Act for Promotion of Use of Wood in Public Buildings (Law No. 36 of 2010 of Japan) was enforced in 2010. The promotion of the use of wood can contribute to the prevention of global warming etc. A public building in a low layer is supposed to attempt making to timber construction by this act. Moreover it is expected that the building such as apartment houses comes to be made from timber construction. For effective use of the Japanese wood, CLT (Cross Laminated Timber), which had been used in Europe, was standardized by JAS (Japanese Agricultural Standard) as a building material in 2014. Among the objections and the troubles of buildings in Japan, the sound insulation performance is one of the most serious issues, especially floor impact sound insulation. We, however, have little knowledge about sound insulation of CLT building. Therefore we built a 3-story CLT model building for experiment and investigated the floor impact sound insulation and the flanking floor impact sound insulation. This paper presents the results of floor impact sound insulation and the surfaces vibration in a sound-receiving room. The results showed the influences of damping material, ceiling and floating on the floor impact sound insulation, and the floating floor showed possible improvements in the heavy-weight and the light-weight floor impact sound insulation of CLT building. The vibration velocity level of the ceiling was the largest. However, it is necessary to decrease the vibration velocity level of the sound-receiving room’s wall for improvement of the heavy-weight floor impact sound insulation by using damping material.

Acoustic design guidelines for houses for hearing impaired seniors – In the framework of Korean building codes

Hearing impairment is a part of the natural ageing process for many people, similar to the occurrence of wrinkles on the face. In order to improve the quality of life for old age seniors, it is necessary to provide a built environment that is appropriate for hearing impairment. The listening ability of the elderly is significantly diminished, particularly in noisy and reverberant environments due to hearing loss. A basic design guideline for houses built for hearing impaired seniors is that excessive noisy and reverberant environments should be avoided. The purpose of this paper is to develop housing acoustic design guidelines that consider hearing loss due to old age relative to natural factors of everyday life, through a detailed literature review. The guidelines take into consideration floor impact sound, heavyweight floor impact sound, unit-to-unit sound insulation, indoor background noise sources, reverberation time, ceiling height, light–fan switch, bell–chime system and illumination level.

Effect of the suspended ceiling with low-frequency resonant panel absorber on heavyweight floor impact sound in the building

This study investigated the effect of the suspended ceiling panel with low-frequency resonant panel absorber on heavyweight floor impact sound. The resonant panel absorber was designed with a perforated top panel, an air gap with or without glass wool, and a bottom panel to ensure a high absorption coefficient in the low-frequency range around 100 Hz. Absorption coefficient measurements were carried out first in the reverberation chamber for resonant panel absorbers varying with the hole diameter of the top panel, the thickness of the glass wool and the air gap between the top and bottom board. As a result, the glass wool had the greatest influence on the absorption coefficient, and the highest absorption coefficient of the resonant panel absorber was about 0.6 in the band of 100 Hz. Floor impact sounds after installing the suspended ceiling with the best resonant panel absorber were also measured in test building using heavyweight floor impact sound sources (bang machine and rubber ball) and compared with result for normal suspended ceiling with gypsum board. Heavyweight floor impact sound by the resonant panel absorber was decreased by 2 dB and 4 dB in single number quantity (Li,Fmax,Aw) for bang machine and rubber ball, respectively. In particular, the resonant panel absorber reduced by 6 dB in 125 Hz octave band with the largest absorption coefficient.

Effect of the static compressive load on vibration propagation in multistory buildings and resulting heavyweight floor impact sounds.

Experiments were performed to identify the mechanism of heavyweight floor impact sound transmission through floors in a high-rise apartment building. Vibration and sound levels on each floor of the multistory building were measured. The vibration generated at a given floor was transferred to multiple adjacent floors with decreasing amplitudes proportional to the distance from the excited floor. This vibration transfer introduced significant sound transmissions. The structural static load varied depending on the floor location due to differences in the weight of the structure above the floor, especially for wall construction buildings. The static load at the wall of the bottom floor was the largest among the different floors. The influence of this static load on the impact sound generation was investigated through tests in the actual building and the scale model, respectively. The results were numerically analyzed using the spectral element method. With the increasing static load, the resonance frequencies of the floor increased due to the change in the vibration modes of the structure. The modulated sound generation from the floor vibrations transmitted to multiple layers with larger magnitudes due to this static load.

重量衝撃源の変化による床衝撃音レベルの互換性に関する検討

The car tire and the rubber ball are standard impact sources to measuring floor impact sound. Both impact sources have same impact time, but different frequency characteristics. Purpose of this paper is to examine the correlation of two impact sources by comparing with frequencies in each floor impact sounds, and clarify the compatibility of two impact sources. We found that both floor impact sounds are correlated with octave frequency of 63Hz and under, uncorrelated with 125Hz and over. Therefore, we can make equivalent evaluation of heavy weight floor impact sound at 63Hz band.

Difference in subjective magnitude between heavy-weight floor impact sources using auditory experiment

Difference in subjective magnitude between heavy-weight floor impact sources was investigated using two auditory experiments. In the first experiment, subjective magnitude to various level (41~56 dB, L’i,Fmax,Aw) of heavy-weight floor impact sound by bang machine, impact ball and children’s jumping was investigated using rating scale method (7 points scale). And then, point of subjective equality (PSE) of floor impact sounds by bang, ball and children’s jumping was drawn using relative annoyance judgement method in second experiment. Stimuli were pairs consisting of the reference (fixed sound level in 50 dB, L’i,Fmax,Aw) and test stimulus (varied sound level), and the subjects rated the relative annoyance of test stimuli compared with a reference stimulus using a numerical scale (-3~0~ + 3). Results showed that floor impact sound level by bang machine was 3~4 dB lower than that of impact sound by impact ball in the PSE. It was also found that subjective magnitude of floor impact sound by ball was quite similar as impact sound by children jumping.

High-sound-insulation double floor structure with Helmholtz resonators: Experimental study on effect of resonator specifications

We have developed a high-sound-insulation double floor structure using Helmholtz resonators. The main targets of this structure are a lot of old apartment buildings that should be renovated, which have thin slabs and cannot sufficiently insulate floor impact sound. The proposed double floor structure greatly improved the insulation performance for heavy-weight floor impact sound in a real old apartment building with 110-mm slab: about 10 dB for 63-Hz and 125-Hz octave bands. In this presentation, experimental results are shown using a small unit structure partially taken out from the whole double floor structure to thoroughly grasp the actual vibration phenomenon. The results are compared to calculation results obtained from a two-particle system theory. Main conclusions are summarized as follows: (i) A sufficiently large rigidity of the resonator walls and a large number of resonator necks are required for obtaining a clear dip in the vibration transmissibility as calculated from the two-particle system theory. (ii) The horizontal and vertical displacement of the resonator necks hardly affects the vibration transmissibility. (iii) The effects of other factors such as the neck length and neck number are qualitatively predictable by the two-particle system theory.

Japanese standards of measurement method and rating for floor impact sound insulation

Among the objections and the troubles of buildings in Japan, the floor impact sound is one of the most serious issues. The floor impact sounds are classified in a heavy- and a light-weight floor impact sound by the characteristic of the impact source. One is the floor impact sound caused by human jumping, running, or walking and the other is the floor impact sound caused by falling lightweight object. The measurement and rating method for floor impact sound insulation is standardized in JIS (Japanese Industrial Standard). JIS A 1418-2 is method using standard heavy/soft impact sources, a car-tire source (a bang machine) and a rubber ball source. The heavy-weight floor impact sound insulation is started in Japan. JIS A 1418-1, which is corresponded to ISO140-7, is method using standard light impact source, a tapping machine. The evaluation for the floor impact sound insulation is standardized in JIS A 1419-2 which is corresponded to ISO 717-2. This paper summarizes the trends for the floor impact sound ins...

Comparison of the Vibration and Acoustic Characteristics of Floor Structural System for Multi-Family Housing

Floor impact noise recently became a serious social problem. Among the different floor impact sounds, heavy weight floor impact noise rose in importance. To compare the vibration and the acoustic response of each experimental unit model for apartment buildings, six kinds of experiment and analysis were carried out. One of them was on the wall system that is often used at construction sites. The others were on the column system consisting of a rahmen, a flat plate, a void slab, a joist slab, and a band beam. In the comparison of the experiment and numerical results, the heavy weight floor impact noise of the wall system was found to be larger than that of the column system. It was shown that the void slab system is an effective system, and the study results showed that analysis of the site characteristics is sufficiently considered because the experiment result is sensitive.

Correspondence between two types of rating indices for the heavy weight floor impact sound insulation of residential buildings

Of the two types of rating indices for the heavy weight floor impact sound insulation, the method of utilizing a rubber ball impact source combined with A-weighted sound level and the method utilizing a tire impact source combined with L-rating curve, the advantage of the former has been reported. In order to extend the advantage, the possibility was studied of estimating the rating utilizing the rubber ball impact source, based on the measurement results utilizing the tire impact source, especially for the case of a double leaf wooden floor. The correlation between the indices is not high enough to estimate one of them directly from the other with an accuracy not incorrectly estimating the rating grade of 5dB step. The use of predictor variables, such as the special specifications of the double leaf wooden floor, for example, the use of sound insulation sheet, and the floor impact sound levels in the 31.5-Hz, 63-Hz and 125-Hz bands, is possibly able to increase the accuracy. Three principal types of multiple regression equation were derived through the analysis of measurement results in existing residential buildings.

Classification of heavy-weight floor impact sounds in multi-dwelling houses using an equal-appearing interval scale

Classifications of heavy-weight floor impact sounds based on subjective responses were suggested by conducting two experiments. First, statements describing perceptual acoustic qualities related to floor impact sounds in residential buildings were collected and assessed with respect to the degree of annoyance levels. Equal-appearing interval scaling for indicating level of annoyance caused by floor impact sounds was then created using these statements. As a next step, heavy-weight floor impact sounds with different LA,Fmax and temporal decay rates (DRs) were evaluated in terms of annoyance using both the Likert scale and the equal-interval statement scale in laboratory conditions. Five categories for heavy-weight floor impact sounds were suggested based on the annoyance responses. The extent of acoustic comfort in each class was clearly captured by the statements related to the range of LA,Fmax for each class. Effects of DR and noise sensitivity on the classifications were significant. Differences between the class criteria for impact sounds with DR 60 dB/s and 30 dB/s were approximately 5 dBA. In addition, significant differences were found between the high and low noise sensitivity classification groups for impact sounds in the 50–60 dBA range.

An empirical study in predicting heavy-weight floor impact sound levels in the 31.5 Hz octave band using driving point impedance

In studies of floor impact noise, increasing attention has been paid to the lower frequency range below 100Hz. Recently, several studies have suggested the importance of including the 31.5Hz octave band in their evaluations. In this band, the floor impact sound is audible but has not been studied sufficiently. The accuracy of two types of so-called ‘impedance’ methods is investigated for the purpose of predicting heavy-weight floor impact sound levels in the 31.5Hz octave band. Although impedance methods are widely used, they are not usually applied to the 31.5Hz octave band. One of the two models is the usual method, in which the sound field of the receiving room is assumed to be diffuse; and the other is a possible variation in which no acoustical mode is assumed in the receiving room. Floor impact sound levels were estimated from driving point impedance levels measured in existing multiple-dwelling buildings and were compared with the measured floor impact sound levels. The results indicate that a hybrid of the two models, with their use depending on the length of the longer side of the receiving room, has the advantage of minimizing the maximum error. However, the hybrid method is unable to improve the general correspondence between measured and calculated values. A simple statistical correction corresponding to the clamping condition of the slab edges is determined to improve the correspondence. A more precise evaluation of the vibration transmission characteristics within a slab would be necessary for further minimization.

Cause and perception of amplitude modulation of heavy-weight impact sounds in concrete wall structures

This study investigated amplitude-modulation effects on the heavy-weight floor impact sound caused by a vibration of concrete wall construction. The fundamental resonance of a floor in concrete wall construction consists of two closely spaced vibration modes. These modes were identified from experimental modal analysis of an actual multi-story building. The modes corresponded to in-phase and out-of-phase vibrations of the upper and lower floors. The rigidity of the side walls had influence on the difference between the natural frequencies of the two modes. Low-frequency modulated sounds were generated in a room by the simultaneous excitations of the two vibration modes. The heavy-weight impact sounds were analyzed using auditory experiments to determine the amplitude-modulation effects on the perceived annoyance. The highly modulated impact sounds were judged to be 3–5 dB more annoying than the one having the same level without modulation. Consequently, impact sound transmission from floors connected by less rigid side walls exhibited lower annoyance.

데크플레이트와 경량성형재가 결합된 슬래브의 차음성능에 대한 실물실험 평가

This study is to explore floor impact sound and sound insulation of reinforced concrete structure with void-deck slab system which combines polystyrene void foam and T-shaped steel deck plate. A void-deck slab system can effectively reduce the amount of concrete used and hence the mass of a reinforced concrete slab. Also void slab system has dynamically favorable for bending. Three-bay 2-story building was constructed as a mock up test specimen using void-deck slab system and floor impact sound was measured to valuate sound insulation performance. Light weight floor impact and heavy weight floor impact were investigated. Light weight floor impact pressure levels were 32dB, 28dB, and 29db at representative locations which are 1 st level in the floor impact sound insulation performance grading system. The heavy-weight floor impact pressure levels were 44dB, 45dB, and 43dB at representative locations which are 2 nd level in the floor impact sound insulation performance grading system. Therefore void-deck slab system can be used in public housing apartment building in terms of not only effectively reduced construction materials but also floor impact sound insulation.