• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.363-374
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• 2018

The façade is an important, complex, and costly part of a building, performing multiple objectives of value to the occupants, like protecting from wind, rain, sunlight, heat, cold, and sound. But the frequency of façade fires in large buildings is alarming, and has multiplied by seven times worldwide over the last three decades, to a current rate of 4.8 fires per year. High-performing polymer based materials allow for a significant improvement across several objectives of a facade (e.g., thermal insulation, weight, and construction time) thereby increasing the quality of a building. However, all polymers are flammable to some degree. If this safety problem is to be tackled effectively, then it is essential to understand how different materials, and the façade as a whole, perform in the event of a fire. This paper discusses the drivers for flammability in facades, the interaction of facade materials, and current gaps in knowledge. In doing so, it aims to provide an introduction to the field of façade fires, and to show that because of the drive for thermal efficiency and sustainability, façade systems have become more complex over time, and they have also become more flammable. We discuss the importance of quantifying the flammability of different façade systems, but highlight that it is currently impossible to do so, which hinders research progress. We finish by putting forward an integral framework of design that uses multi-objective optimization to ensure that flammability is minimized while considering other objectives, such as maximizing thermal performance or minimizing weight.

• Earthquakes and Structures
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• v.12 no.1
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• pp.13-21
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• 2017

Recent seismic events occurred in Italy (Emilia-Romagna 2012, Abruzzo 2009) and worldwide (New Zealand 2010 and 2011) highlighted some of the weaknesses of precast concrete industrial buildings, especially those related to the connecting systems traditionally employed to fasten the cladding panels to the internal framing. In fact, one of the most commons fails it is possible to observe in such structural typologies is related to the out-of-plane collapse of the external walls due to the unsatisfactory behaviour of the connectors used to join the panels to the perimeter beams. In this work, the strengthening of a traditional industrial building, assumed as a case study, made by precast reinforced concrete is proposed by the adoption of a dual system allowing the reinforcement of the structure by acting both internally; by pendular columns and, externally, on the walls. In particular, traditional connections at the top of the walls are substituted by devices able to work as a slider with vertical axis while, the bottom of the walls is equipped with two or more hysteretic dampers working on the uplift of the cladding panels occurring under seismic actions. By means of this approach, the structure is stiffened; obtaining a reduction of the lateral drifts under serviceability limit states. In addition, its seismic behaviour is improved due to the additional source of energy dissipation represented by the dampers located at the base of the walls. The effectiveness of the suggested retrofitting approach has been checked by comparing the performance of the retrofitted structure with those of the structure unreinforced by means of both pushover and Incremental Dynamic Analyses (IDA) in terms of behaviour factor, assumed as a measure of the ductility capacity of the structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5861-5869
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• 2014

Existing studies of building exterior materials have focused on the colors or textures of cladding, and in terms of a design planning approach, have focused on the use of the environment and equipment and fire safety topics from an engineering perspective. As a result, little research has been done on performance guidelines for exterior materials, specifically according to the building type. Research into eco-friendly cladding materials is also in the rudimentary stage in a practical sense. In this study, the use of exterior materials over the last ten years in domestic construction was analyzed. The usage status of building exterior materials was evaluated quantitatively by frequency analysis, and its environmental performance is proposed through complex (qualitative + quantitative) analysis. The average value of the exterior material type number used for all analyzed buildings was 2.59. Glass, metal, stone, resin, cement, wood, and clay were used in that order with regard to the usage status. The analysis found that five of the materials satisfied the high efficiency and eco-friendly grading in terms of the four characteristics of an eco-friendly exterior. A list of eight eco-friendly elements was also proposed. The eco-friendly elements and characteristics of the exterior materials were derived to provide basic guidelines for domestic construction companies and design offices.

• Wind and Structures
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• v.4 no.4
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• pp.279-298
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• 2001

The greatest suction on the cladding of flat roof low-rise buildings is known to occur beneath the conical vortices that form along the roof edges for cornering winds. In a companion paper, a model of the vortex flow mechanism has been developed which can be used to connect the surface pressure beneath the vortex to adjacent flow conditions. The flow model is experimentally validated in this paper using simultaneous velocity and surface pressure measurement on a 1 : 50 model of the Texas Tech University experimental building in a wind tunnel simulated atmospheric boundary layer. Flow visualization gives further insight into the nature of peak suction events. The flow model is shown to account for the increase in suction towards the roof corner as well as the presence of the highest suction at wind angles of $60^{\circ}$. It includes a parameter describing vortex suction strength, which is shown to be related to the nature of the reattachment, and also suggests how different components of upstream turbulence could influence the surface pressure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.33-34
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• 2022

The purpose of this study was to provide basic data for applying oyster shells and egg shells as fireproof cladding materials by substituting fine aggregates for oyster shell powder and egg shell powder, and comparing strength and fire resistance performance. The reason for the high strength was thought to be that the oyster shell had higher strength than the egg shell itself, and both ESP and OSP were measured at a backside temperature of less than 500℃, so it was judged that it could be used as a fireproof coating for steel structures.

• Journal of the Korean Solar Energy Society
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• v.24 no.3
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• pp.101-109
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• 2004

This research investigates the life-cycle energy consumption of the windows used for the building's exterior cladding, and its environmental potential aspects by utilizing the LCA. The research scope has taken account of the entire life-cycle of the windows from the extraction of raw materials to its disposal, of which given sample building type is an apartment building. Results gained from the LCA of the windows as one of the steps in analysis reflects the current global interest and analysis trend towards the world's environmental issue on all fields of industry including the architectural industry, of which its newly established standards of architectural windows can further promote more environmentally sustainable factor compared to the previous analysis (focused more on energy efficiency assessment of the use stage).

• Journal of KIBIM
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• v.9 no.3
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• pp.8-18
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• 2019

Precast concrete manufacturing has proved economies of scale through the repetitive production by means of standardization, automation, and prefabrication. Advanced digital design and fabrication technologies can empower its benefits by enabling mass customization in the building design and construction. This study analyzed five case studies in terms of 1) design intent and background, 2) module development and facade construction, 3) integrated process among project stakeholder. This article has attempted to establish the following three points in conclusion: 1) Form generating digital design tools such as Rhino, CATIA, Generative Component, and Digital Project were implemented to produce parametric surface pattern and rationalization to maximize existing precast manufacturing benefits. Also, BIM program has been used to promote coordination and communication among engineering consultants and contractors, 2) In addition to traditional precast concrete materials, GFRC, RFP, brick cladding precast and 3D printed mould have been introduced to reduce the weight and cost and to comply the code from the zoning, seismic, and fireproof requirements, 3) Design-assist contract, design-assist financial support, and co-location measures have been introduced to facilitate collaboration between architect, fabricator, and contractor from the beginning of the project.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.531-542
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• 2018

Building energy demands have highly risen in modern society; thus, It is necessary to reduce building energy demands especially commercial buildings adopting a curtain wall architecture. Curtain wall architectures have a high ratio of windows which is a vulnerable in heat insulations as cladding. In order to complement insulation performance of windows in these buildings, there are various methods adopted often such as installing blinds, wing wall and films. There are two suggestions of this paper. 1) WWR (Window-to-Wall Ratio) makes a impaction of energy demands in buildings. 2) Another one is an efficiency of blind systems which are installed in buildings in order to reduce cooling demands. It is also critical to make fundamental model for low-energy building construction by processing a lot of simulation As a result by this study, 1) an external blind system is more useful for reducing cooling energy demands rather than an internal blind system. 2) Buildings which have a large window require more amount of cooling demands. In case of WWR 45%, it needs more cooling energy rather than WWR 15% model's 3) Adopting blind system would reduce energy demands. WWR 45% model with external blind systems reduces about 4% of cooling energy demands compared to same model without any blind systems.4) it is necessary to study an efficiency of blind systems combined with renewable energy and it will be possible to reduce more energy demand in building significantly.

• Steel and Composite Structures
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• v.34 no.2
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• pp.189-213
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• 2020

Stainless-clad (SC) bimetallic steels that are manufactured by metallurgically bonding stainless steels as cladding metal and conventional mild steels as substrate metal, are kind of advanced steel plate products. Such advanced composite steels are gaining increasingly widespread usage in a range of engineering structures and have great potential to be used extensively for large civil and building infrastructures. Unfortunately, research work on the SC bimetallic steels from material level to structural design level for the applications in structural engineering field is very limited. Therefore, the aim of this paper is to investigate the material behaviour of the SC bimetallic steels under the cyclic loading which structural steels usually could encounter in seismic scenario. A number of SC bimetallic steel coupon specimens are tested under monotonic and cyclic loadings. The experimental monotonic and cyclic stress-strain curves of the SC bimetallic steels are obtained and analysed. The effects of the clad ratio that is defined as the ratio of the thickness of cladding layer to the total thickness of SC bimetallic steel plate on the monotonic and cyclic behaviour of the SC bimetallic steels are studied. Based on the experimental observations, a cyclic constitutive model with combined hardening criterion is recommended for numerical simulation of the cyclic behaviour of the SC bimetallic steels. The parameters of the constitutive model for the SC bimetallic steels with various clad ratios are calibrated. The research outcome presented in this paper may provide essential reference for further seismic analysis of structures fabricated from the SC bimetallic steels.

• Wind and Structures
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• v.3 no.2
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• pp.97-115
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• 2000

The technique of proper orthogonal decomposition is potentially useful in specifying the fluctuating surface pressure field around structures. However there has been a degree of controversy over whether or not the calculated modes have physical meanings. This paper addresses this issue through consideration of the results of full scale experiments, and through an analytical investigation. It is concluded that the lower, most energetic modes are likely to reflect different fluctuating flow mechanisms, although no mode is likely to be associated with just one flow mechanism or vice versa. The higher, less energetic modes are likely to represent interactions between different flow mechanisms, and to be significantly affected by the number of measurement points and measurement errors. The paper concludes with a brief description of the application of POD to the problem of building ventilation, and the calculation of cladding pressures.