• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.249-250
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• 2018

To control the floor noise generated in the apartment building, a method of reinforcing the floor at the floor is applied. However, since existing buildings are difficult to reinforce upper generations, the ceilings of lower generations should be reinforced. The purpose of this study is to analyze the reduction effect by measuring the impact noise after reinforcing the floor soundproofing material on the ceiling of the existing building. In order to ensure the economical efficiency and flame retardancy of the products used as building interior materials, the existing polyurethane foam was impregnated with mineral to prepare test specimens and attached to the concrete slab surface. As a result, it was shown that heavy impact sound can reduce 2dB~5dB and light impact sound can reduce 4~8dB.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.9
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• pp.805-812
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• 2011

This study investigated the characteristics of heavy-weight floor impact sounds of box-frame type structure using 1:10 scale model. Ten types of floor structures(bare slabs and floating floors) were evaluated in terms of dynamic stiffness and loss factor. Floor vibrations and radiated sounds generated by simulated impact source were also measured. The results showed that the bakelite was appropriate for simulating concrete slab in the 1:10 scale model, and surface velocity and sound pressure level of concrete slab measured from the scale model showed similar tendencies with the results from in-situ in frequency domain. It was also found that dynamic behaviors of layered floor structures in the 1:10 scale model were similar to those in a real scale. Therefore, the use of 1:10 scale model would be useful for evaluating the heavy-weight floor impact sound insulation of layered floor structures when the frequency-dependent dynamic properties of each material are known.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.930-935
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• 2005

In order to synthesis of the materials and modulus for floor impact sound reduction, we investigated effect on dynamic elastic modulus of floor impact sound reduction materials and module made by inorganic porous materials, EVA chips and so on. We find correlation property between dynamic elastic modulus and light-weight impact noise. And we measured the dynamic elastic modulus of materials and module for floor impact sound reduction. And we predicted reduction efficiency on floor Impact Noise of those. The dynamic elastic modulus is reduced by increase of filler contents and filler species. When the materials for floor impact sound reduction is consisted of l5wt% EVA Chip and l5wt% inorganic porous materials, its dynamic elastic material is the lowest. And when the module is consisted of PE (upper side), PS embossing board(lower side) and the materials for floor impact sound reduction(middle), its dynamic elastic material is the lowest.

• Journal of Korean Society of Rural Planning
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• v.11 no.3 s.28
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• pp.53-57
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• 2005

Up to recently building are constructed focusing on the convenience of residential condition. However, environmental-friendly materials is required for construction as people are spending more time inside buildings and causes of many problems like sick-building syndrome are known due to the noxious gases and polluted air originated from construction materials. Although loess(hwangtoh) is an environmental-friendly material, it has limitations in compressive strength far a construction material. The purpose of this study is to suggest the optimal ratio of loess(hwangtoh) mortar by tests of compressive strength comparing with standard strength of floor finishing mortar and evaluate the usability of loess(hwangtoh) mortar for floor finishing material through an impact test, a cracking test and a abrasion test. Based on the results of this study, 86% of loess(hwangtoh) and 14% of inorganic binder is suggested for the optimal mixture ratio of loess(hwangtoh) mortar. Moreover, the characteristics of loess(hwangtoh) is suitable for floor finishing material in impact, crack, abrasion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1320-1325
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• 2009

The sources of the vibration of railway vehicles in the cabin are usually bogie, axle, and wheel. The vibrations are transmitted through the floor structures of railway vehicle. The floor structure is the combination of bottom plate, plywood, and rubber. In this research the vibration transmission is measured experimentally and analyzed numerically to find the transmission characteristics of the vehicle floor structures. The result shows that the vibration characteristic of soft rubber is better than hard rubber or wood as the connecting material between the bottom plate and the plywood.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.415-422
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• 2003

In an apartment buildings, the floor Impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation, it is necessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to suggest the supplementary formula(equation) and constant k considering vibration transmissibility in order to predict more precisely heavy floor impact sound by Impedance Method that have been briskly studied in Japan from comparing the measured values with the predicted values. The analyzed results had showed that if the damping material was glass wool or rubber, k=5 was proper and if the damping material was polystyrene foam, k>5 was desirable.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.12-22
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• 2006

The purpose of this study is to evaluate visual preferences of the methods for river embankment based on seasonal changes and to reveal the relationship between visual preference and effective factors, which are the physical and esthetic elements inside the river. For this research seven river embankment methods including concrete block, concrete wall, gabion, and vegetated concrete block were selected in Dongchon of Gwangyang. Twenty-eight pictures by the four pictures of each embankment method based on seasonal changes, the winter and summer of the first and second years after construction were used for a photo-questionnaire by 49 participants. In the analysis of the relationship between visual preference and effective factors, the independent variables included eight factors: form of the material, harmony with the surroundings, the cleanness of river floor, the green area of embankment methods, the water area in river floor, the stone and sand area in river floor, the planting area in river floor, and the area of embankment itself. The result of this study are as follows. First, visual preference in summer was higher than in winter, and the summer landscape of the second you scored the highest value for visual preference. Second, similarly to the way the vegetated concrete block produced a green effect, cobblestone and gabion embankments made of natural materials scored higher than others, whereas the concrete retaining wall scored the lowest of all methods because of it's artificiality. Third, the seven independent variables, except form of the material, are proved statistically significant at the 5% level. The water area in river floor, harmony with the surroundings, the planting area in river floor, and the cleanness of the river floor were revealed as more effective factors influencing visual preference. The research results suggest that the riverscape has to be controlled in terms of seasonal change and embankment methods. Natural materials and green effects in embankment methods are more important for increasing landscape preference, and the landscape factors inside a river should also be considered important variables. It is recommended that advanced study on other factors affecting visual preference of the riverscape be carried out to support this research.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1149-1152
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• 2007

Many kind of damping materials are generally used on concrete slab in apartment building to reduce floor impact noise level. Lately, multi-layered damping material that is consist of several materials are used to improve the effect of floor impact noise insulation. In this study, dynamic stiffness of multi-layered damping material that is consist of common materials such as expanded polystyrene(EPS), expended polyethylene(EPE), ethylene vinyl acetate(EVA) and polyester was investigated. It was found that dynamic stiffness of multi-layered damping material could be estimated if know value of each layer that compose whole structure. And it was found that dynamic stiffness of whole structure did not change even if change order that build layer.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.161-167
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• 2023

Recently, floor impact sound has become a serious social problem in Korea. There is an increasing need to improve floor impact sound performance using floor covering installed on the floor of apartment houses. KS F ISO 717-2 and KS F 2863 require measurement under conditions in which the resilient material is not installed. But most apartment houses in Korea install resilient materials to reduce floor imapct sound. The performance evaluation method of floor covering should provide reduced performance for use by residents of apartment houses with resilient materials. Therefore, this paper proposes a reduction performance evaluation under the conditions in which a resilient material is installed to verify the performance of floor covering.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.7
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• pp.501-508
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• 2014

Floor finishing materials such as floor coverings and floor mats can reduce floor impact noise easily. When an impact was applied to the floor, its finishing material is deformed and the impact force that was applied to the concrete slab is changed. The softer finishing materials were, the more impact force decreased. An experimental study was performed using 14 PVC floor coverings and 16 floor mats to capture the characteristics of impact force and impact noise in the residential buildings. The test results show that the impact force spectrum and the floor impact noise spectrum have a linear relationship in the case of a bare concrete slab, and the characteristics of impact force reduction are the same as those of floor impact noise reduction.