Journal of Architectural Engineering

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal.

Curtain wall systems made of an aluminum frame and infilled with glass panes are extensively used in present day high-rise buildings. The vertical members of the aluminum frame, known as mullions, are complex-shaped and are primarily subjected to bending action when the curtain wall panels are exposed to wind pressure or suction loading. This paper investigates the section moment capacity of 6063-T6 aluminum alloy mullion sections subjected to wind actions using a numerical study. An experimental study conducted to determine the section moment capacity of the mullions is summarized in this paper. The results from an experimental study on the mechanical properties of 6063-T6 aluminum alloy mullions are then presented including a suitable stress–strain model. Finite element models were developed to determine the section moment capacities of tested mullion sections, and the details of the finite element modeling procedure and the results are presented in this paper. The developed models included mullions used in the structural and captive glazing systems subjected to both wind pressure and suction loading and were validated using the available test results. Finite element analysis (FEA) results were compared with the predictions from three design methods, the limiting stress method (LSM), the direct strength method (DSM), and the total moment capacity approach (TMCA), based on which the most suitable design method is recommended.

Since poor design deliverables can generate significant project cost overruns and schedule delays, producing high-quality design deliverables is critical. To improve design quality on building projects, this study focuses on identifying quality-problematic design deliverables and their associated design defects. The authors surveyed 51 industry professionals, asking them to assess the frequency of quality problems on 84 common building design deliverables. From this survey, 14 design deliverables were identified as problematic. Then, the survey results were analyzed in two different ways: according to the area of expertise of the respondents and organization type. The results showed significant differences between the two groups in each case in assessing the frequency of the 14 problematic design deliverables. In addition, the authors identified a total of 47 high-priority design defects associated with the problematic design deliverables through conducting phone interviews with 66 professionals. The results of these research activities offer comprehensive insight into design deliverable quality problems to enable practitioners to enhance overall design quality on building projects.

Being able to perform an effective design review is a fundamental skill that every design or construction student should possess. Performing a design review requires critical thinking, analysis, and communication skills. To support the acquisition of these skills, this study investigated the impact of a virtual reality game, the design review simulator (DRS), in a classroom environment. To assess the impact of the game, the authors performed a crossover experiment with 120 students. The students were split into groups and were asked to perform design reviews in two treatment conditions, 2D drawings or the DRS. A knowledge test was administered at the end of different treatments to collect quantitative data on the students' performance. Results from this research indicate that the DRS supported students in identifying a higher number of design mistakes. Furthermore, students that played with the DRS after performing 2D drawings reviews scored significantly higher in the knowledge test. The research results contribute to the growing knowledge base on the implementation of VR in the classroom and in supporting students in meeting learning objectives related to design review skills. In particular, the research illustrated that the benefits of VR found in the construction industry in terms of improved communication, user involvement, and feedback collection could be translated into the classroom environment.

This paper documents an empirical experiment conducted in August 2014 as proof of concept for a new method of constructing concrete shells. An idea initially presented by the first author in 2012, it uses redeployable gridshells onto which fabric is midstressed and concrete applied. Primarily, this system addresses key issues that led to their decline in use: construction methods/formwork systems were not reusable, nor were they easily customizable to create different shapes. Employing 27 man-hours over seven days, two concrete shells were achieved using the same reusable and reconfigurable formwork. Lightweight (0.6 kg) PVC gridshell formwork supported 106.92 kg of concrete to create a concrete shell that covered 1.11 m² (floor area). The construction verifies a low-cost (£6.06/m²) efficiency and material utilization in the construction of very strong wide-spanning thin concrete structures. Detailed analysis of formwork behavior during construction and detailed measurements of resultant shell results prove this new method of deployable gridshells as a reusable and reconfigurable formwork to construct very strong concrete shells very quickly. Whilst the emphasis of the research focused on the construction process, the vaults were tested and sustained a failure load of 4.2 kN (4.32 times their deadweight), applied as a point load at the crown.

Model building codes and standards in the United States find their bases in a probabilistic model of glass load resistance (LR). In general, architectural flat glass design predicated on these model building codes and standards is restricted to rectangular glass lites continuously supported along one, two, three, or four sides. When a design professional wishes to use glass with an odd shape (i.e., a nonrectangular shape), design procedures in the model building codes and standards regress to a maximum stress approach. A maximum stress approach to design represents a much different philosophy than does the probabilistic approach. When compared to the probabilistic approach, designs based upon a value of maximum allowable stress may result in much less efficient design. Therefore, the need exists for a design approach for odd-shaped glass lites that has a probabilistic basis for glass load resistance. The primary analysis tools available to engineers today are based on the finite-element method and can be applied to a wide range of different glass lite geometries. The authors developed a nonlinear finite-element model and applied the glass failure prediction model (GFPM) to the nonlinear finite-element model output to determine probability of breakage for combinations of selected flat odd-shaped glass lite geometries and loads. The authors compared the LR of the odd-shaped glass lites to the LR of flat glass lites with the LR of rectangular glass lites having the smallest dimensions so that they would encompass the odd-shaped lites. The authors also compared the maximum principal stresses determined for the flat odd-shaped glass lites (loaded with a pressure equal to the LR of the flat odd-shaped glass lites) from the nonlinear finite-element model to recommended values of maximum allowable stress from model building codes and standards.

Architectural assets, regarded as the common heritage of the whole of humanity, can be passed onto following generations without losing their structural integrity and authentic architectural characteristics by means of conservation and preservation activities. Although the historical, aesthetic, and authenticity values of architectural heritage come into greater prominence than many other criteria, and require preservation in the locations they were originally constructed in, some factors make this impossible. Where there is no other choice, relocation of historical buildings to a new location is today accepted as one of the preservation methods. Owing to their nonlinear material properties, the relocation of historical buildings that are constructed with a brick or stone masonry system creates a serious risk as regards to their structural integrity. The process is planned and the optimum method of relocation is specified according to the geometric and material properties of the historical buildings. This study examined the structural integrity problems that may occur due to possible human- or nature-caused geometrical irregularities during relocation. Numerical models and analysis obtained by the finite element method are used in order to determine the possible results of these unexpected cases within the scope of the proposed relocation scenario. The inspiration for the numerical models and relocation scenario was drawn from an endangered monument: “Orta Kapi” (the Middle Door) in Hasankeyf, which will be flooded soon due to an ongoing dam construction project. Findings of this study could help the planning of relocation methods that can enable more suitable executions of architectural heritage preservation by relocation.

A whole building life cycle assessment (LCA) was performed on a Living Building, focusing on impacts from green building materials, a decentralized water system, a net-positive use phase, and the end-of-life of structural materials. The material processes used in this LCA were adjusted from standard to green by removing the use of toxic chemicals; results show carcinogenic impacts decreased by up to 96%. The septic system used for wastewater treatment contributes to 41% of the global warming potential [GWP, kg CO₂eq (carbon dioxide equivalent)] over the building's assumed 100-year lifespan due to methane emissions. The on-site solar panels generate more electricity than the site demands, allowing for 44,000 kWh of green energy to be returned to the grid based on 1 year of performance. Lastly, an exploratory scenario analysis performed on multiple waste streams for structural materials shows that the GWP impacts for the end-of-life could vary from +14,000 to −10,500 kg CO₂eq depending on the waste stream. The results of this LCA indicate that the case study building is net-zero energy and water, but not net-zero carbon.

The objective of this research is to demonstrate that parts of decommissioned wind turbine blades can be repurposed for infrastructure applications for a sustainable future of the wind power industry. The purpose of this paper was to develop a methodology to conduct detailed structural engineering design of composite material parts extracted from wind turbine blades. A large section extracted from a 100-m long blade was repurposed as a roof for a small (approximately 40 m²) single-story masonry house. Geometric and material properties were taken from the blade design documents. A three-dimensional graphical model was created from the exterior surface and material layups. The roof was designed using the load and resistance factor design method familiar to civil engineers. Analysis of stresses and defections was conducted using hand calculations and the finite element method. The results of the analyses showed that the roof is within code mandated stress and deflection limits. The methodology developed could be applied to other wind blade repurposing concepts.

There is evidence that when people are exposed to sociobehavorial and socioeconomic disadvantage they become more susceptible to the impacts of poor environmental quality and experience exacerbated health outcomes as a result. In addition, existing literature clearly establishes a relationship between the built environment (e.g., housing, transportation infrastructure) and its effects on physical health, yet no studies to date have examined indoor air pollution and its effect on quality of life (combining physical and mental health). The goal of this study was to move beyond physical health and associate indoor air pollution to reduced psychological and social wellbeing. This study focuses on indoor air quality (IAQ) data and select results from a quality of life (QOL) survey from 41 homes in Pittsburgh, Pennsylvania, USA. Each home was monitored for 7–31 days collecting continuous samples of carbon dioxide, particulate matter (PM), black carbon, relative humidity, radon, temperature, formaldehyde, and total volatile organic compounds; colocated outdoor samples were also collected. Seasonal effects on IAQ were observed across the study. More specifically, a buildup of volatile organic compounds from cleaning/sanitizing products and other anthropogenic sources (e.g., human metabolism, personal care products, and clothing) were attributed to the enclosed nature of homes during heating months. The challenges of aged and deteriorating infrastructure also impacted pollutant concentrations. Radon levels in homes built before 1940, were on average 69% higher than conventional homes built after 1940. The largest PM concentrations were observed in homes where occupants smoked indoors, or the homes were occupied by pets. Based on the QOL survey, bivariate analysis of the 41 questions suggests household income (r = 0.57), poor mental health days (r = −0.71), depression (r = −0.77), anxiety (r = −0.66), everyday functionally (r = −0.62), and living in a safe and secure environment (r = 0.52) are significant factors that impact QOL. Multiple linear regression was then performed to determine the strength of each predictor variable, and to forecast the effect of indoor PM on the overall QOL score. The analysis revealed a significant relationship between indoor PM and individual dimensions of QOL (household income, and living in a safe and secure environment), but there was not a dominant effect on the overall QOL score. Although the effect was less profound than expected, our analysis serves as the basis of future work and marks the beginning of needed research in IAQ and its effect on social and emotional wellbeing.

Historic buildings have originally embodied sustainable features. These features responded to the microclimate and site where the building is located. However, with climate change and urban density, active techniques become essential to ensure occupants’ indoor comfort. In this regard, the present study attempts to examine and assess the sustainable retrofitting of a historic building in order to maximize energy efficiency without affecting its unique historic character. It also addresses the shortcomings in the literature by considering the cost variation among retrofitting strategies and cost reduction in terms of energy consumption. In this framework, a historic building located on Istanbul University was analyzed in the framework of the case study. The study evaluated the implementation of several retrofit techniques, active and passive, using the energy software DesignBuilder. The implemented retrofit strategies were subsequently evaluated in terms of life cycle cost (LCC), aiming to determine the most cost-optimal and energy-efficient solution. The resultant improvements in energy consumption can serve as a model for forthcoming historic retrofitting projects that take into consideration both economic feasibility and historic buildings' values.

The structural design of sealed insulating glass units for wind loads involves complex structural mechanics procedures that address load sharing between two glass lites that vary in thickness, dimensions, and heat treatments. In exhaustive studies of windows in mid- and high-rise buildings, it has been shown that any one of six commonly used window glass lites [6, 8, 10 mm (1/4, 5/16, 3/8 in.), heat-strengthened and fully tempered], acting alone, can represent the minimum load resistance of dual-lite, sealed insulating glass units that contain this lite when paired with any one of the six listed lites. Further, the minimum load resistance of each of these six lites can be related to building height by employing wind load design of current standards. An innovative technique permits selection of dual-lite insulating glass unit constructions for mid- and high-rise buildings in the Inland Zone and a Hurricane Zone that meet wind load provisions of building codes based upon building height alone, without calculations.