Glazed Curtain Wall Research Articles

The influence of fire size on breakage time for double glazed curtain wall system in enclosure fire

The prediction of breakage time on curtain wall system is an important factor for the fire protection system in high-rise buildings. The breakage of glass is caused by thermal deformation of curtain wall frame. Also, thermal deformation could be influence by fire size. Therefore, in this study, numerical analysis is performed to investigate the effect of fire size on breakage time on double glazed curtain wall system. To investigate the effect of fire size on breakage time, the pool size is varied 0.4x0.4 m, 0.5x0.5 m and 0.6x0.6 m, respectively. As a result, the breakage times of glass are decreased as 170 s, 100 s and 38 s for the pool size varying 0.4x0.4 m, 0.5x0.5 m and 0.6x0.6 m, respectively. From the numerical results, the present study suggests the useful relationship between the heat release rate and breakage times as follow: t = -0.341×Q e + 257.64 (252.3 kw < Q e < 637.9 kw). In order to prevent breakage of glass curtain wall due to fire, fire protection system must be operated

Seismic damage mitigation of the glazed building façade

Glass as a material in architecture and civil engineering represents a challenge, and it is often a material of choice for designers, used both for the building interior elements as well as for cladding of building. The paper has addressed specifically the glazed curtain wall fa?ades and the earthquake-induced issues related to them. A review of the standing standards and practice in this field are provided. The paper presents some of contemporary solutions for damage mitigation of glazed building envelopes caused by earthquakes, such as: solutions with clearances between glass and its frame, earthquake-isolated curtain wall system, modified geometry of glass corners and friction damping connectors.

Seismic assessment and finite element modelling of glazed curtain walls

Glazed curtain walls are facade systems frequently chosen in modern architecture for mid and high-rise buildings. From recent earthquakes surveys it is observed the large occurrence of non-structural components failure, such as storefronts and curtain walls, which causes sensitive economic losses and represents an hazard for occupants and pedestrians safety. In the present study, the behavior of curtain wall stick systems under seismic actions has been investigated through experimental in-plane racking tests conducted at the laboratory of the Construction Technologies Institute (ITC) of the Italian National Research Council (CNR) on two full-scale aluminium/glass curtain wall test units. A finite element model has been calibrated according to experimental results in order to simulate the behavior of such components under seismic excitation. The numerical model investigates the influence of the interaction between glass panels and aluminium frame, the gasket friction and the stiffness degradation of aluminium-to-glass connections due to the high deformation level on the curtain walls behavior. This study aims to give a practical support to researchers and/or professionals who intend to numerically predict the lateral behavior of similar facade systems, so as to avoid or reduce the need of performing expensive experimental tests.

Critical Places Regarding Fire Insulation of Glazed Curtain Walls Test Specimens

Critical Places Regarding Fire Insulation of Glazed Curtain Walls Test Specimens

Critical Places Regarding Fire Insulation of Glazed Curtain Walls Test Specimens

Critical Places Regarding Fire Insulation of Glazed Curtain Walls Test Specimens

An experimental investigation into stratum ventilation for the cooling of an office with asymmetrically distributed heat gains

The performance of stratum ventilation in an office with a glazed façade was investigated. An electric heating film, hung on a side wall of the test chamber, was employed to simulate the heat gain via a glazing curtain wall. In total, 13 experimental cases were conducted by adjusting the heat generation of the heating film, the temperature and the airflow rate of supply air. The performance of stratum ventilation was evaluated by examining the distributions of temperature, velocity and dimensionless carbon dioxide (CO2) concentration, effective draft temperature for stratum ventilation (EDTS), predicted mean vote index (PMV), and efficiencies of heat and contaminant removals. The experimental results demonstrated that stratum ventilation performed well in heat removal and contaminant removal. Quality inhaled air for the occupants was provided in all experimental cases. It was found that the glass wall temperature had a significant influence on thermal comfort of occupants. When the inner surface temperature of glass wall closed to 40 °C, the PMV values approached the upper bound of the comfort zone. For every case wherein the cooling load was 90 W/m2 or below, and the supply air temperature was 19–21 °C, thermal comfort of the occupants was provided. Both the efficiencies of heat removal and of local contaminant removal improved with increasing airflow rate at constant supply air temperature. Therefore, stratum ventilation could perform well in cooling offices with highly asymmetric distribution of heat gains.

Numerical simulation of thermal mass enhanced envelopes for office buildings in subtropical climate zones

The morning power overloading for office cooling is often the aftereffect of not using air conditioning on hot summer nights. Integration of phase change material (PCM) into the office building envelope can be a solution, but, prior to usage, the PCM layer has to be optimized to deal with a number of alternating boundary conditions. The diurnal alternation of the heat load level facing the building envelope is very critical in predicting PCM behavior and cooling energy consumption in a real PCM integrated office building in Hong Kong.EnergyPlus numerical simulation of a PCM layer with specific properties and encased in between two layers of a building envelope was adopted to assess PCM efficiency in relation to its placement, thickness and orientation to the sun, causing moderate and elevated heat loads. The optimized PCM envelope with windows was simulated as a part of a realistic office building model to estimate the air conditioning power balancing on the hottest days and during the entire hot season.The results show that the considered PCM layer should be placed at the inner building envelope part, i.e., close to the office interior. The optimization stage revealed the negative effect of the excessive PCM thermal mass bringing indoor overheating in certain combinations of diurnal heat loads. This is an outcome of not using air conditioning at nights and on Sundays. In the realistic office building model, the negative PCM effect diminishes, though the PCM reduces the morning peak power by up to about 5%. The PCM impact is clearly shown in the comprehensive results for the entire cooling season, where effective smoothing of the AC power demand is indicated. The PCM usage, however, considerably prolongs the AC operation in a narrow power mode (200–244kW) that can aid the chiller selection.The study demonstrates that the morning peak power can be effectively managed via the PCM optimized building envelope in subtropical climate zones. For an office building, a combined window and building envelope with PCM can be an excellent alternative to fully glazed curtain walls.

FIRE RESISTANCE OF ALUMINIUM GLAZED CURTAIN WALLS, Test results comparison depending on the side of fire exposure

This paper discusses the main issues related to the fire resistance of aluminium glazed curtain walls including the tests methodology and way of classification of this type of building elements. Moreover, the paper presents the comparison of fire resistance test results of large test specimens of curtain walls in full configuration depending on the side of fire exposure. Temperature rises have been compared on unexposed surface of the curtain walls tested for standard and external fire exposure. To made the comparison four test specimens of glazed aluminium curtain walls in full configuration, were tested. Curtain walls had the same transom – mullion structure. Two test specimens were tested for external fire exposure, and two for standard fire exposure. Dimensions of exposed surfaces were 5000 x 4500 mm (width x height) for external fire exposure and 5000 x 4800 mm (width x height) for internal fire exposure.

Study on critical places for maximum temperature rise on unexposed surface of curtain wall test specimens

The paper discusses the main issues related to the fire resistance of glazed curtain walls including the tests methodology and way of classification of this type of building elements. Moreover, the paper presents an attempt to determine the weak points of aluminium glazed curtain wall test specimens regarding to the maximum temperature rise measurements, based on the fire resistance tests performed in recent years by Fire Research Department of Building Research Institute. The paper analyse the results of temperature rise on unexposed surface of 17 aluminium glazed curtain wall specimens tested for internal fire exposure in accordance with EN 1364-3:2006 [3] and EN 1364-3:2014 [4], which achieved the fire resistance class of min. EI 15. © Owned by the authors, published by EDP Sciences, 2016 Language: en

New Courthouse at El Ejido

The courthouse at El Ejido has a trapezoid floor plan (47 m × 55/26 m) and comprises two distinct volumes that are structurally connected at the basement level and by the footbridges on the upper storeys. A third trapezoid unit featuring a glazed curtain wall facade cantilevers 8 m off the main facade of the front volume. This facade is a structural diaphragm wall, constituted by nine rows of vertical precast concrete members separated by horizontal cast-in-place, self-compacting concrete chords. The location of the courthouse in a seismic area and the small number of horizontal supports for the facade make this wall potentially vulnerable. The high risk, in particular, during construction required careful planning based on a detailed analysis of the interaction between the structure and the ancillary resources used to build it.

THE SEISMIC BEHAVIOUR OF CURTAIN WALLS: AN ANALYSIS BASED ON NUMERICAL MODELLING

Abstract The paper proposes a numerical model to estimate the structural behaviour of a stickbuilt glazed curtain wall system subjected to an imposed displacement of the supports in the plane of the wall. We discuss the role of the parameters that influence on the maximum inter-storey drift corresponding to the service limit state of the wall. The considered parameters are the dimensions of the glazed panel, the gap between the panel and the aluminium frame and the gap between the supports and the mullions. We discuss the problem of remnant deformation of glazed panels, and of misalignment as serviceability criteria. Comparisons are made to laboratory testing results.

스틸 커튼월의 단열성능 및 결로방지성능 평가

Metal curtain wall systems are widely used in high-rise commercial and residential buildings. While aluminum is the most frequent used frame material, steel framing is also reemerging as a high-performance material in glazed curtain walls due to less thermal conductivity and design flexibility. The purpose of this study is to evaluate thermal performance of a steel frame curtain wall system by comparing with a aluminum frame curtain wall system. The thermal transmittance was measured according to KS 2278, and condensation resistance was calculated by the test results according to KS F 2295. The steel framing test specimen showed lower thermal transmittance and temperature descending factor compared to the aluminum framing test specimen.

Fire resistance tests of large glazed aluminium curtain wall test specimens – results comparison

Four test specimens, glazed aluminium curtain walls in full configuration, were tested. Curtain walls had the same transom – mullion structure, with: • transoms and mullions made of the same aluminium profiles, with two types of insulation inserts (in each test one type of the insulation inserts), • glass panes of the same glass product group and dimensions of: ◦ 1680× 3198mm (width × height) for biggest glass pane orientated vertically, ◦ 1980× 1628mm (width × height) for biggest glass pane orientated horizontally. • non-transparent panels of the same construction and dimensions, • similar design (profiles, and consequently glass panes and panels of the same construction on the exposed area). Two test specimens were tested for external fire exposure, and two for standard fire exposure. Dimensions of exposed surfaces were 5000× 4500mm (width × height) for external fire exposure and 5000× 4800mm (width × height) for internal fire exposure. As a result the heated area was over 2 times greater than the minimum heated area required in EN 1364-3:2006 [3]. The distance between the mullion fixing anchors was 5000mm in both cases. All tested specimens were of the same transom – mullion structure with aluminium profiles sections of 50× 115mm (transoms) and 50× 130mm (mullions), fig. 1. Two types of insulations inserts were used in profiles, each type for pair of tests (external and internal fire exposure). Two types of glass panes were used in test specimens, each type for pair of tests (external and internal fire exposure). Glass panes were of symmetrical structure.

A Review of the Behavior of Structural Silicone Glazing Systems Subjected to a Mega-Earthquake

Abstract Structural silicone glazed (SSG) curtain wall systems have offered architects and owners the ability to design a facade with unique aesthetic features since the 1970s. While their ability to durably withstanding natural weathering and even high wind locations across the globe has been well established, their performance under seismic events is less well recorded. This paper presents a review of the performance of SSG systems following the 8.8 magnitude earthquake that shocked Chile in Feb 2010, which registered within the top five recorded in past history. Field reviews of existing low-, medium-, and high-rise buildings were inspected in the aftermath of the event to evaluate the performance of the different SSG variations of this system type (two-sided, four-sided, stick, unitized, among other variations) combined with other facade components such as: type of glazing, glass sizes, interstory drift, width of structural grid, slab/beam rigidity, etc.

Evaluation of the Structural Sealant for Use in a Four-Sided Structural Sealant Glazing Curtain-Wall System for a Hospital Building

Abstract Cathedral Hill Hospital (the California Pacific Medical Center) is a 15-story building designed to be constructed in downtown San Francisco. The curtain-wall system for this building is primarily of unitized design employing a four-sided structural sealant glazing (SSG) system. This paper initially introduces the building and its curtain-wall design. Next, the summary of the results of full-scale racking tests on stick-built mockups of the curtain-wall system developed to evaluate the structural sealant performance are presented. Stick-built mockup, instead of unitized system, was chosen to initially evaluate the behavior of sealants under racking conditions. The mockups were designed to determine the behavior of the glass, framing, connections, and more importantly, the structural silicone under racking displacements following the AAMA 501.6 protocol. The test results (stress–strain relationships) on the structural sealant to determine tensile adhesion properties at selected temperatures and UV exposures are discussed and comparisons to the finite-element analysis results are presented. The wind load and seismic design of the sealants, including the finite-element modeling and analysis of a typical panel to evaluate the stresses in the structural sealants, are presented as well. The allowable stress issue in structural sealants for seismic design of four-sided SSG systems is discussed in light of the new information generated for this project.

The Influence of Glass Types on the Performance of Air-Conditioned Office Buildings in Australia

Windows are one of the most significant elements in the design of buildings. Whether there are small punched openings in the facade or a completely glazed curtain wall, windows are usually a dominant feature of the building's exterior appearance. From the energy use perspective, windows may also be regarded as thermal holes for a building. Therefore, window design and selection must take both aesthetics and serviceability into consideration. In this paper, using building computer simulation techniques, the effects of glass types on the thermal and energy performance of a sample air-conditioned office building in Australia are studied. It is found that a glass type with lower shading coefficient will have a lower building cooling load and total energy use. Through the comparison of results between current and future weather scenarios, it is identified that the pattern found from the current weather scenario would also exist in the future weather scenario, although the scale of change would become smaller. The possible implication of glazing selection in face of global warming is also examined. It is found that compared with its influence on building thermal performance, its influence on the building energy use is relatively small or insignificant.

Structural Analysis and Design of Glazed Curtain Wall Systems

Glazed curtain wall systems have been gaining popularity in recent times, and are commonly found in all types of commercial, industrial, institutional and residential buildings. The design of curtain wall façade systems covers aesthetic considerations, weather proofing and structural evaluation. Structurally the curtain wall is designed for in-plane and out-of-plane loads and movements. The size and the profile of the glazed curtain wall are normally specified by the architect, while the structural design is undertaken by façade engineers. There is very limited published literature available on the structural design for engineers especially for the design of point fixed glazed curtain wall systems. In this paper, an overview of the methodology for the design of both unitised glazed curtain wall systems and point fixed glazed curtain wall systems is presented.

Analysis on Integral Performance of Unit Glazing Curtain Wall Considering the Contribution of Glass Rigidity

Based on integral property of unit glazing curtain wall (UGCW), considering the co-effect of glass and grids, set up the calculating method of cooperation of glass and grids; through the numerical simulation analysis with this method, we can conclude that take the glass’s rigidity into consideration is both reasonable and economical.

Drift Intolerant Façade Systems and Flexible Shear Walls: Do we Have a Problems

It is well known that structural shear walls provide an excellent strategy for improving the seismic response of buildings. This paper discusses two buildings recently constructed in Adelaide that contain high aspect ratio shear walls. In both buildings, the inter-storey drift capacity of glazed curtain wall façade systems was exceeded by shear wall design solutions based on strength alone. In order to prevent a life safety hazard from falling glass, design changes were required to ensure inter-storey drifts were reduced to values that could be accommodated by the drift intolerant façade systems. These examples raise concern regarding the adequacy of the blanket “deemed to be satisfied” shear wall drift provisions of the 2005 Draft Standard for Earthquake Actions, in which the simple adoption of shear walls removes the requirement for the designer to estimate drift.

Façade Renovation of the Wexner Center for the Arts

Abstract The Wexner Center for the Arts went through a major façade renovation to fix the water leakage and condensation problems. The work included replacing glazed skylights, curtain walls, and roofs. This paper describes how renovation work has been done with modern technologies to study thermal and lighting performance on the new façade. In addition to the computational analysis, a full scale mock-up was constructed in a laboratory for air, water, and structural test, and to evaluate the condensation resistance performance. Currently there are no industry standards for condensation evaluation for a mock-up of this size. The mock-up test method refers to ASTM C 1199, “Standard Test Method for Measuring the Steady-State Thermal Transmittance of Fenestration Systems Using Hot Box Methods,” and AAMA 1053 test procedures but with modifications to suit the project. The new façade of the Wexner Center is a perfect example of how façade design can be done with modern analyses tools and a coordinated design approach to deliver an environmentally efficient cladding system. The paper also describes the issues for the current test standards to the projects that have specific design conditions.