• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.33-43
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• 2005

This paper presents the test results and evaluations for the energy dissipation capacity and compressive performance of light-weight hybrid panels. A total of 26 full-scale specimens of light-weight hybrid panels were tested. The parameters include the presence of light-weight foamed mortar, the specific gravity of light-weight foamed mortar (0.6, 0.8, 1.0, 1.2), the finishing materials (light-weight foamed mortar, OSB [Oriented Strand Board], gypsum board), the shape of bracing (x, ~), and the size of panels (1P-900 mm 2,400 mm, 2P-1,800 mm 2,400 mm). The results of the cyclic tests are somewhat different from those of monotonic tests, due to the different specific gravity of light-weight foamed mortar. It was found from the compressive tests that the ultimate strength and initial stiffness are increased by means of light-weight foamed mortar (2~2.5 times in ultimate strength and 2~3 times in initial stiffness).

• Journal of Korean Society of Steel Construction
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• v.19 no.5
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• pp.455-462
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• 2007

The purpose of this paper is to evaluate experimentally the compressive performance of horizontal joints for light-weight hybrid panel in-filled with light-weight foamed mortar. The parameters include the presence of light-weight foamed mortar, the specific gravity of light-weight foamed mortar (0.8, 1.2), the finishing materials (light-weight foamed mortar, Oriented Strand Board [OSB], gypsum board), and the fixed shape of the hybrid panel. As the improved details for fixed end, the peak strength and the stiffness of the light-weight hybrid panel are enhanced as follows: 1.07-2.7 times in peak load, 15-24 times in initial stiffness. The peak strength of the light-weight hybrid panel obtained by the test result is in agreement with the calculations, which is the criterion value according to the domestic code.

• Journal of Korean Society of Steel Construction
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• v.16 no.4 s.71
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• pp.397-406
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• 2004

This paper presents the test and evaluation results on the shear strength and stiffness of a light steel stud wall from a lightweight foamed mortar (lightweight hybrid wall). The use of a lightweight foamed mortar was aimed at improving structural performance, thermal performance, and finish. Studiesshowed that it did not affect thermal performance, but it contributed to structural performance and finish when the unit weight was more than 0.8 (Editor's note: Please indicate the unit of measurement.). In this study, 14 specimens-whose parameters included the specific gravity of the lightweight foamed mortar (0.6, 0.8, 1.0, 1.2), the spacing of the stud (450 mm, 600 mm, or 900 mm), finishing materials (such as lightweight foamed mortar, OSB, and gypsum board), and bracing-were manufactured. Three typical, steel house-framing specimens were added to compare the test results with the 14 specimens. The results of in-plane shear tests show that the use of lightweight foamed mortar (1.15~5.38 times stronger, 1.45~13.7 times stiffer) results in ultimate strength and initial stiffness. In addition, it was possible to widen the stud spacing to up to 900 mm without decreasing shear strength. It was very important to prevent the lightweight foamed mortar from shrinking and to secure the adhesion between the steel stud and the lightweight foamed mortar to improve structural performance.

• KIEAE Journal
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• v.10 no.3
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• pp.89-96
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• 2010

In comparison with ordinary or heavy-weight concrete, light-weight air void concrete has the good aspects in optimizing super tall structure systems for the process of design considering wind load and seismic load by lightening total dead load of buildings and reducing natural resources used. Light-weight air void concrete has excellent properties of heat and sound insulating due to its high amount porosity of air voids. So, it has been used as partition walls and the floor of Ondol which is the traditional Korean floor heating system. Under the condition of which the supply of light-weight aggregates are limited, the development of light-weight concrete using air voids is highly required in the aspects of reduced manufacturing prices and mass production. In this study, we investigated the physical properties and thermal behaviors of specimens that applied different mixing ratios of foaming agent to evaluate the possibility of use in the structural elements. We proposed the estimating equation for compressive strength of each mix having different ratio of foaming agent. We also confirmed that the density of cement matrix is decreased as the mixing amount of foaming agent increase up to 0.6% of foaming agent mixing ratio which was observed by SEM. Based on porosity and compressive strength of control mortar without foaming agent, we built the estimating equations of compressive strength for mortars with foaming agent. The upper limit of use in foaming agent is about 0.6% of the binder amount. Each air void is independent, and size of voids range from 50 to $100{\mu}m$.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.53-68
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• 2011

This paper presents the fundamental parameters for designing the NATM Composite Lining to be used in NATM tunnel construction. Firstly, the concept of NATM Composite Lining behaviour is introduced and reviewed in construction-performance. For the fundamental study, the optimal mix ratio tests and backfill material property tests to develop high-quality composite lining (PC panel lining) are fundamentally carried out. And the light-weight foamed mortar which is used for backfill material is developed. Full-scale loading tests to verify a performance of the NATM Composite Lining is also performed. From this research, it is clearly found that the NATM Composite Lining is very applicable method to considerably increase the stability and constructability of tunnel structure.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.69-84
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• 2011

This paper presents the applicability of NATM Composite Lining method in domestic tunnel construction sites. Firstly, in order to produce high quality PC Panel, optimal steam curing condition is reviewed. And in preparation for fire inside the tunnel, the fire-resistance test of PC Panel is carried out. The constructability of NATM Composite Lining method and the drainage ability of light-weight foamed mortar is also evaluated through field construction test. And PC Panel combination program is developed to calculate the quantity of PC Panel efficiently. Besides, economic evaluation for NATM Composite Lining method is conducted. From this research, it is clearly found that NATM Composite Lining method is applicable to domestic tunnel construction site.