• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.75-84
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• 2002

In order to find out impact insulation properties, various types of current radiant floor heating systems and light-framed floors that are used in light-framed residential buildings were evaluated for two types of impact sources at the same time. Sound Pressure Level (SPL) was different from each impact sources for those spectrum patterns and peaks. In case of light-framed floor framework, the excitation position and the assumed effective vibrating area have effects on sound pressure level but it is not considerable, and Normalized SPL was reduced for each frequency by increasing the bending rigidity of joist. The mortar layer in the radiant heating system had relatively high density and high impedance, therefore, it distributed much of the impact power when it was excited, and reduced the Normalized SPL considerably. Nevertheless, Increasing a thickness of mortar layer had little influence on SPL. Ceiling components reduced the sound pressure level about 5~25 dB for each frequency. Namely, it had excellent sound insulation properties in a range from 200 to 4,000 Hz frequency for both heavy and lightweight impact sources. Also, there was a somewhat regular sound insulation pattern for each center frequency. The resilient channel reduced the SPL about 2~11 dB, irrelevant to impact source. Consequently, current radiant floor heating systems which were established in light-framed residential buildings have quite good impact sound insulation properties for both impact sources.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.1005-1010
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• 2001

Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top layers with thin thicknesses, typically 5~ 15mm. The purpose of this study is to evaluate basic properties of self leveling materials using polymer modifier as kinds of SBR, PAE, SUBA. Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as in order to facilitate the workability required. The self leveling materials using four types of polymer dispersion are prepared with polymer-cement ratios which respectively range from 50%, 75%, and were tested for basic characteristics such as adhesion in tension, crack resistance test, rebound test after the preparative tests for unit weight, air content, consistency ratio etc. The results show almost as equal quality as existing commercial industrial flooring when mortar is modified by polymer dispersion. Adhesion in tension of polymer modified mortars using each SBR and PAE emulsion was over 10 kgf/$cm^{2}$. Crack or flaw derived from shrinkage is strongly dependent on the type of polymer dispersion because of each different total solid of polymer. It is judged that polymer modified mortar with self-leveling can be very well suited for Floor-finished.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.243-248
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• 2001

The objective of this study is to investigate the thermal conductivity of cement mortar for apartment housing floor using expansive admixture, copper fiber, cower lathe, hollowed aluminum plate. According to test results, temperature at point (a) located above heating pipe does not show significant variation with age, and temperature at (b), which is located at the finishing surface above heating pipe, and temperature at (c), which is located at center surface between heating pipe has remarkable change. Temperature distribution sat (b) are in order for, structure containing copper fiber>plain structure>structure containing hollowed aluminum plate>structure containing expansive admixture. Temperature distribution, shows high tendency in order for, structure containing copper fiber>structure containing copper lathe>structure containing hollowed aluminum plate>plain structure>structure containing expansive admixture. (a) estimation of temperature distribution is determined with the variation of temperature between (b) point and (c) point during 60 minutes heating.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.97-98
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• 2012

This research examined the fundamental property of the MgO as the fundamental study that substituted the MgO in the low melting point modified sulfur mortar to examine the physical properties.In this research, the table floor, flexural strength test, and compressive strength test were performed. And as the replacement ratio increased, the floor showed the tendency to increase. And when being the replacement ratio 3%, the flexural strength and compressive strength made the high strength. In case of being substituted for over 5% they displayed the tendency that the intensity is degraded.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.155-160
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• 2000

In this paper, we investigated quality properties for the expansive of the CaO-$CaSO_4$ family which used to compensate dry-shrinkage in the floor mortar of On-Dol heating System. This experimental study established the mix condition with quantity of the expansive and is to investigate the relativity between the compress strength and the length change and the relativity between the chemical properties and the length change with the analysis of the physical and chemical properties. As a result of the study, the expansive is controlled by more the CaO than the $CaSO_4$. The relativity between the compress strength and the length change is expressed by exponential function, showing that if the expansive performance is increased, the compress strength is decreased. And the relativity between the chemical properties and the length change is only relative the quantity of the F-CaO among the chemical properties, is expressed by the second order function, showing that if the F-CaO is increased, the expansive performance is increased.

• Magazine of RCR
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• v.8 no.2
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• pp.30-34
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• 2013

• Magazine of RCR
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• v.7 no.4
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• pp.44-45
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• 2012

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.160-165
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• 1999

Osmotic pressure induced by semi-permeability of hardened cement pasts and cement mortar was studied, which was considered to be a cause of failure such as separation and blistering of floor coatings or wall coatings from the concrete substrate. The specimens with a water cement ratio of 45, 60 and 75% were installed between the solution of sodium chloride and distilled water. First, we measured water flux from distilled water to sodium chloride and the ion flux of Na+ and Cl- through the specimens. Then, we measured osmotic pressure induced by semi-permeability of the specimens using an apparatus which was specially developed for this study. It was made clear that hardened cement paste and cement mortar have properties of semipermeability, and the osmotic pressure is closely related to their water cement ratio. Finally, we calculated the osmotic pressure according to Staverman's equation, which was obtained for organic membranes, and tried to explain quantitatively the observed pressure.

• KIEAE Journal
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• v.12 no.1
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• pp.73-81
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• 2012

Floor impact sound has been most annoying for years among the noises which are produced in apartment. This study aims to analyze the improvement of floor impact sound by comparing the results of the test which was carried out for the wall slab type apartment and moment frame apartment, and also for the effect of advanced vibration isolation layer. Moment frame structure that main structure consists of column and slab has shown better performance for the heavyweight impact sound comparing with wall slab type structure which is general type in Korea. Stiffness of floor system was raised by reinforcing the stiffness of vibration isolation layer, and it was analyzed how much the floor impact sound performance was improved. The result showed that the reinforced floor had better performance than the existing floor system that uses lightweight porous concrete as vibration isolation material. In addition, a system used wire mesh in mortar showed improvement of floor impact sound than a system without wire mesh, and better performance for the frequency bands lower than 160 Hz which causes floor impact problem in wall slab type apartment.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.1-10
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• 2024

In-situ carbonation technology represents a form of mineral carbonation that integrates CO₂ into the fabrication process of cementitious construction materials, capturing CO₂ as calcium carbonate(CaCO₃) through a reaction between calcium ions(Ca²⁺) and CO₂ released during cement hydration. This investigation examines the application of in-situ carbonation technology to a variety of floor dry cement mortar formulations commonly used in local construction projects. It assesses the effects of varying the CO₂ injection flow rate and total volume of CO₂ injected. Additionally, the study evaluates the impact of reducing the quantity of cement used as a binder on the final product's quality.