• 한국태양에너지학회 논문집
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• 제40권2호
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• pp.11-23
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• 2020

The application of the high-performance insulation materials for buildings seems to be an essential measure for reducing energy use in buildings. Phenolic foam is a readily available insulation material with thermal conductivity of about 0.018 to 0.020 W/(mK). It has the advantage of higher thermal resistance and better fire resistance compared to other conventional building insulation materials. Insulation material used for building envelope is regarded as one of the decisive factors for building's energy load. Furthermore, the degradation of its thermal performance over time increasingly affects the building's energy use demand. Generally, the life span of conventionally built buildings is expected to be more than 50 years, so the long-term performance of insulation materials is critical. This paper aims to evaluate the long-term performance of phenolic form boards through an accelerated aging test. The tests were conducted according to BS EN 13166 and KS M ISO 11561. Based on the results of the accelerated aging test, the thermal performance variation of the material was analyzed, and then its aged value after 25 years was computed. Also, the characteristics of the phenolic foam board's long-term performance were also examined based on the standard testing methods adopted.

• Smart Structures and Systems
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• 제13권3호
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• pp.473-500
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• 2014

Tuned mass dampers (TMDs) have been installed in many high-rise buildings, to improve their resiliency under dynamic loads. However, high-rise buildings may experience natural frequency changes under ambient temperature fluctuations, extreme wind loads and relative humidity variations. This makes the design of a TMD challenging and may lead to a detuned scenario, which can reduce significantly the performance. To alleviate this problem, the current paper presents a proposed approach for the design of a robust and efficient TMD. The approach accounts for the uncertain natural frequency, the optimization objective and the input excitation. The study shows that robust design parameters can be different from the optimal parameters. Nevertheless, predetermined optimal parameters are useful to attain design robustness. A case study of a high-rise building is executed. The TMD designed with the proposed approach showed its robustness and effectiveness in reducing the responses of high-rise buildings under multidirectional wind. The case study represents an engineered design that is instructive. The results show that shear buildings may be controlled with less effort than cantilever buildings. Structural control performance in high-rise buildings may depend on the shape of the building, hence the flow patterns, as well as the wind direction angle. To further increase the performance of the robust TMD in one lateral direction, active control using LQG and fuzzy logic controllers was carried out. The performance of the controllers is remarkable in enhancing the response reduction. In addition, the fuzzy logic controller may be more robust than the LQG controller.

• Advances in Energy Research
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• 제5권1호
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• pp.65-77
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• 2017

The latest UK Climate Projections (UKCP09) show that mean daily temperatures will increase everywhere in the United Kingdom. This will significantly affect the thermal and energy performance of the current building stock. This study examines an institutional fully glazed building and looks into the changes in the cooling loads and thermal comfort of the occupants during the occupied hours of the non-heating period. Furthermore, it investigates the effect of relative humidity (RH) on thermal comfort. The Design Summer Year (DSY) 2003 for London Heathrow has been used as a baseline for this study and the DSY 2050s High Emissions scenario was used to examine the performance of the building under future weather conditions. Results show a 21% increase of the cooling loads between the two examined scenarios. Thermal comfort appears to be slightly improved during the months of May and September and marginally worsen during the summer months. Results of the simulation show that a relative humidity control at 40% can improve the thermal comfort for 53% of the occupied hours. A comparison of the thermal comfort performance during the hottest week of the year, shows that when the relative humidity control is applied thermal comfort performance of the 2050s is similar or better compared to the thermal comfort performance under the baseline.

• 한국건축시공학회지
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• 제7권3호
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• pp.123-130
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• 2007

This study investigated the fundamental properties and shrinkage properties of high performance concrete with water/binder ratio of 0, 30 and with combination of expansive additive and shrinkage reducing agent. According to the results, the fluidity of high performance concrete showed lower the using method in combination with expansive additive and shrinkage reducing agent than the separately using method of that, so the amount of superplasticizer increased when the adding ratio of expansive additive and shrinkage reducing agent increased. However the air content of concrete increased when used in combination with expansive additive and shrinkage reducing agent, so the amount of AE agent decreased. The compressive strength showed the highest at 5% of expansive additive, and decreased with an increase of the amount of shrinkage reducing agent. Furthermore, in order to reduce the shrinkage of high performance concrete, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than separately using method of that. Autogenous shrinkage was predicted using JCI model. Because JCI model is unable to consider the effect of EA and SRA, correction factor should be added to enhance the accuracy.

• 국제초고층학회논문집
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• 제5권3호
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• pp.221-232
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• 2016

With the booming of construction and property industries in China, the demand for high-rises and mega-scale buildings with more integrated building functions, open- and tailor-shaped outlooks, better connections to municipal infrastructures, and higher grades of building importance has been increasing in the past two decades. The seismic design and engineering of such modern mega-buildings face engineering challenges such as hazard mitigation of extreme actions and surroundings, integrated structural frameworks and building skins, complex connections, and overall construction efficiency. It is the work of a new generation of civil and structural engineers to enhance engineering efficiency and achieve overall engineering, environmental, and economical effectiveness for these high-rise projects. This paper elaborates the above topics through case studies on the design and construction of four such developments in China. Some rethinking is conducted on evolution in modern seismic engineering and design through innovation to achieve an acceptable level of overall sustainability and building effectiveness.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.18-19
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• 2020

Domestic and foreign high-rise buildings are expected to continue to increase in the future. In addition, recently, residents and landlords are demanding maintenance necessary to secure the performance of sustainable buildings, so an effective management plan is needed. Therefore, this study aims to develop customized technologies that can be effectively applied to building structures by comprehensively analyzing existing technology-based research cases. As a result, it is expected that this will serve as a stepping stone to present a s+ample of future technology development along with a reduction in labor dependency on maintenance and quality improvement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.127-128
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• 2012

Exhaustion of fossil fuels and continued high oil prices, global warming, climate change and to respond to the development and use of alternative energy technologies is expanding rapidly throughout the world. Recently, character of domestic building is appearing by along with economic growth, high-rise, large size, congestion. For this reason, the amount of electrical energy used in a building is increasing. In this study, the applicability of PV modules that are used as roofing and efficiency analysis, and more from the building of BIPV modules built using the activation of alternative energy sources in Korea are aimed want done.

• Earthquakes and Structures
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• 제6권1호
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• pp.45-69
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• 2014

The 2009 L'Aquila, Italy earthquake shook a high density area causing a wide spectrum of damage to reinforced concrete with infill buildings, one of the most common building types used in Italy. The earthquake has proven to be a "full-scale" laboratory to further understand building performance. This paper presents the first results of a joint research effort between the University of Bologna and Degenkolb Engineers, aimed at investigating the seismic behavior of an infilled frame building that collapsed during the earthquake. State-of-the-practice techniques were implemented as a way to determine the reliability of these modeling techniques in anticipating the observed building performance. The main results indicate that: (i) the state-of-the-practice techniques are able to predict the observed behavior of the buildings; (ii) the masonry infills have a great influence on the behavior of the building in terms of stiffness, strength and global ductility.

• 설비공학논문집
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• 제27권3호
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• pp.152-157
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• 2015

Stack effect on high-rise building have negative effect on living environment, energy and life-safety aspect. Thus, it's necessary to find the measure to reduce the stack effect. As a result of field test on a 31-story building, a circulating type stack effect reduction technology was developed, which supplies air in the low stairs and discharges air in the high stairs. To evaluate the performance of this circulating type stack effect reduction technology on building stairs, a 3D numerical analysis was carried out by using Momentum Loss Model for analyzing leakage flow between compartments in a building. Consequently, numerical analysis proved that the stack effect on building stairs was reduced by a circulating type stack effect reduction technology.

• Steel and Composite Structures
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• 제9권2호
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• pp.159-172
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• 2009

Two prestressed steel reinforced high performance concrete (SRC) beams, a nonprestressed SRC beam and a counterpart prestressed concrete beam were tested under low reversed cyclic loading to evaluate seismic performance of prestressed SRC beams. The failure modes, deformation restoring capacity, ductility and energy dissipation capacity of the prestressed SRC beams were discussed. Results showed that due to the effect of plastic deformations of steel beams encased in concrete, the three SRC beams exhibited residual deformation ratios ranging between 0.64 and 0.79, which were apparently higher than that of the prestressed concrete beam (0.33). The ductility coefficients of the prestressed SRC beams and the prestressed concrete beam ranged between 4.65 and 4.87, obviously lower than that of nonprestressed SRC beam (9.09), which indicated the steel beams influenced the ductility little while prestressing resulted in an apparent reduction in ductility. The amount of energy dissipated by the prestressed SRC beams was less than that dissipated by the nonprestressed SRC beam but much more than that dissipated by the prestressed concrete beam.