Journal of Architectural Engineering

Published by American Society of Civil Engineers
Online ISSN: 1076-0431
Publications
Article
This paper provides analytical tools and engineering methods to evaluate the feasibility of the economizer for dual-duct air-handling units. The results show that the economizer decreases cooling energy consumption without heating energy penalties for dual-fan, dual-duct air-handling units. The economizer has significant heating energy penalties for single-fan, dual-duct air-handling units. The penalties are higher than the cooling energy savings when the cold airflow is less than the hot airflow. Detailed engineering analyses are required to evaluate the feasibility of the economizer for single-fan, dual-duct systems.
 
Article
The nave of Santa Maria Novella, a Dominican church in Florence Italy is representative of a Florentine Gothic system of construction. This system, consisting of domical rib vaults on square nave bays, high side aisles, and crypto-buttressing, differs substantially from the French high Gothic system of even-level-crown rib vaults on rectangular bays, with flying buttresses over relatively low aisles. An investigation into the structural aspects of the Florentine Gothic construction system reveals that the domical vaults increase the longitudinal thrust and reduce the transverse thrust, which may require additional precautions to be taken during construction, but entails a less elaborate buttressing system. The domical vaults are found to perform well structurally, with an absence of tensile stresses, and are more suitable for a square bay. In general, the structural system of the nave of Santa Maria Novella is found to be the product of carefully considered structural design, which may be accepted as an alternative to the French Gothic construction system.
 
Article
Currently, there are no Canadian national guidelines for the wind uplift resistance of architectural metal roof systems. Thus, it is difficult to judge their suitability and performance based on a common standard. Given the increasing use of metal roofs, it has been determined that there is a need for the development of a design guide, that would be applicable to all regions of Canada. Metal roofs can be classified into two groups: Structural and architectural. This paper focuses on the wind uplift performance of architectural metal roof systems. Several parameters influence the wind uplift performance of the architectural metal roofs. This study finds that air leakage of the structural deck is one of the significant factors that influences the wind uplift performance. This is based on experimental investigations carried out at the Dynamic Roofing Facility of the National Research Council of Canada, using the Special Interest Group on Dynamic Evaluation of Roofing System dynamic wind test protocol. Architectural roofing panels with three different types of commonly used, seam-interlocking mechanisms (joint details) were investigated. It has been noted that the resistance to wind uplift pressure increases dramatically as the air leakage ratio decreases. A modeling method is also described which quantifies system response by simulating the wind gusts over roof specimens with different leakage ratios that can represent field assemblies. The 1995 National Building Code of Canada was utilized for the estimation of the wind-induced loads and the present study provided extensive experimental data for various systems with each type of seam detail. Based on this analysis, a simplified design procedure was developed. The simplified procedure is presented through case studies of metal roof assemblies located in the Canadian provinces of British Columbia, Ontario, and Quebec.
 
Article
Computer-assisted architectural programming is in its infancy. What there is in terms of architectural programming theory often differs from practice. In the first half of this paper we define relevant terms, provide abrief review of the state of the art, and draw attention to the primacy of architectural programming in design. SEED-Pro is introduced as an intelligent assistant providing structure to the normally open-endedactivities of design. This includes the creation of an architectural program from scratch. In the second, more technical, part of the paper we emphasize three specific topics. The design problem specificationfunctionality is described. The generation and evaluation of the emerging architectural program is discussed. An approach to the decomposition of the architectural program into alternative hierarchies is provided.The paper concludes with a discussion of what is and remains to be accomplished.
 
Article
This paper provides a brief history of networked multimedia technology in the United States. The evolution of the Internet and the World Wide Web is outlined. The use of traditional computer technologies byengineering and architectural practitioners and academics is discussed. Use of some new computer technologies by researchers in both professions, including high-speed networks, animated graphicalsimulations, augmented and virtual reality, is also presented, along with a discussion of how they are beginning to be used together on the World Wide Web. Opportunities for refining architectural engineeringresearch, scholarship and practice by expanded use of new networked multimedia technologies are presented. The features of a demonstration testbed networked multimedia package, entitled the FarnsworthHouse Volume are introduced, along with their potential application to some architectural engineering problems. The use of the volume in classes at Columbia University is presented. Advantages anddisadvantages of networked multimedia capabilities embedded in the Farnsworth volume are discussed.
 
Moisture Index (MI) for five locations
Water Vapor Permeability and Liquid Diffusivity of Stucco Materials
b-Temperature contour plot (hygIRC-2D output) for stucco wall with water leakage
Article
The moisture design of exterior walls in a building envelope is an important task that needs to be carried out systematically to generate a sustainable and healthy built environment. Many conventional methods or practice guidelines are available for this purpose, based primarily on local traditions and with limited performance assessment records. In recent years, with the rapid development of global free trade and economy, new wall systems and unconventional materials have been introduced in every part of the world for reasons such as aesthetic appeal, cost effectiveness and so on. However, neither the long-term moisture management performance of these new wall systems nor the uses of unconventional materials have been assessed in a systematic way. The primary reason for this lack of assessment is the absence of a design-oriented methodology to perform the task. This paper presents selected results from a recently completed research project that demonstrate that it is indeed possible to assess the moisture management performance of exterior walls in a systematic way, using a hygrothermal modeling tool together with key inputs from a limited number of laboratory and field investigations. In this project the hygrothermal responses of exterior walls and their components were assessed with a novel moisture response indicator, called the RHT index, which is derived from relative humidity and temperature data over a time period. The results and discussion presented in this paper clearly show the need and usefulness of the application of hygrothermal simulation tool for the optimum moisture design of exterior wall systems in various geographic locations, when sufficient information is available from laboratory and field experiments.
 
Article
This paper presents data from this on going investigation that will help system designers to maximize wind uplift ratings by choosing the appropriate roof components at the early design stage or by replacing/adding components during reroofing to improve uplift resistance. By diagnosing roof system failures, one can identify the weakest link and select design alternatives that can improve the wind resistance. Through a case study, this paper concludes with a procedure for system optimization. Ce document présente des données issues de cette étude en cours qui aideront les concepteurs de systèmes à maximaliser les cotes de soulèvement sous l'action du vent en choisissant les composants de toiture appropriés à un stade précoce de la conception, ou en remplaçant / ajoutant des composants à l'occasion de la réfection de la toiture, dans le but d'améliorer la résistance au soulèvement. Par le diagnostic des défaillances des toitures, il est possible d'identifier le maillon le plus faible du système et de sélectionner des solutions de rechange en matière de conception qui peuvent améliorer la résistance à l'action du vent. Par le biais d'une étude de cas, ce document se termine par l'exposition d'une procédure d'optimalisation des systèmes. RES
 
Typical sandcrete block unit 
Bulk Density Test Results of Sandcrete Blocks
Typical sandcrete block wall construction 
Water Absorption Capacity Test Results of Sandcrete Blocks
Fine aggregate grading curves for suppliers A, B, and C 
Article
Sandcrete blocks are widely used in Ghana as walling units. The quality of blocks produced, however, differs from each manufacturer due to the different methods employed in the production and the properties of the constituent materials. This paper focuses on the impact of quality control practices by suppliers on the quality of blocks produced in the Kumasi (6°548N 1°358E) metropolis. Sandcrete blocks were taken from suppliers and tested for compressive strength, bulk density, water absorption, and dimension tolerances. Fine aggregate samples were also taken from the suppliers and tested for grading, silt, and organic matter content. The study confirmed that mix ratio, quality, and mixing of the constituent materials affected the quality of sandcrete blocks. Visual inspection rather than laboratory testing was adopted as the means of ascertaining the quality by a few of the staff of contractors who had no formal training in quality control. Mix ratios used ranged from as lean as 1:8 to as weak as 1:19 (cement:sand). Blocks produced were also found to be unsuitable for use as load bearing walls. Accepted for publication
 
Article
This paper describes the overall goals of SEED, the approach taken by its developers to achieve these goals, and the subprojects that comprise the entire project. SEED aims at providing computational support forthe early design phase in all aspects that can benefit from such support. It addresses specifically architectural programming, schematic layout design, and the generation of a fully three-dimensional configuration ofphysical building components like structure and enclosure. These tasks are handled by three individual modules, SEED-Pro, SEED-Layout, and SEED-Config. A standards processor is under development tosupport standards and code checking in any module, as is an object database to store and retrieve different design versions, alternatives, and past designs that can be reused and adapted in different contexts(case-based design). Usability issues, especially the interfaces to the modules, receive special attention. Subsequent papers elaborate on these efforts in greater detail. The present paper provides an overview of theentire project and introduces shared concepts presumed known in subsequent papers.
 
Article
Although there are many computer-based tools for analyzing structures whose geometry, topology, and member properties have already been determined, there are very few general-purpose tools to assiststructural designers in synthesizing structural configurations to be subsequently sized, analyzed, and detailed. The comceptual-structural-design submodule of the Software Environment to Support the EarlyPhases in Building Design (SEED-Config) is intended to fill this void. The process starts with a geometric model of the building's massing, a set of functional requirements to be satisfied, and a toolkit oftechnologies capable of generating potential structural system and subsystem alternatives. Structural alternatives can be rapidly generated under designer control to the level of detail desired and evaluated against arange of criteria. Provisions are made to store design cases as well as to retrieve and adapt these to meet new requirements.
 
Article
This paper describes an innovative wall system for use in residential and commercial construction projects that is reusable, uses less dimensional lumber, and is faster to assemble and install compared to traditional stud wall systems. The wall system is an engineered wall design composed of components fabricated from 5.08 × 5.08 cm (2 in.) (nominal dimensions) nailing strips and oriented strand board fins located in the midsection of the nailing strip. Components can be connected to one another by hinges allowing the system to be collapsible. Laboratory testing has shown that this wall system has significantly improved racking capabilities compared to the traditional stud wall system both with and without sheathing. Additional research is required, however, to enhance this wall system's structural characteristics in bending and axial loads. An economic analysis showed that material costs are cheaper for this wall and assembly, and installation times are less compared to traditional stud wall construction. In its present form, this wall system could be used for non-load-bearing applications (e.g., partition walls within a load bearing structure).
 
Article
A workshop on green construction was organized in New Delhi in July 2008 by Jamia Millia University, India and University of Salford, U.K., aiming to increase 'green' practices that are environmentally friendly and energy efficient. The workshop included participants from regulatory bodies, public and private construction companies and researchers. The object of the workshop was to provide an opportunity to capture issues, challenges and research issues in green practices throughout the supply chain in the construction sector in India. The methodology constituted a survey that was provided to all participants, where eight questions were composed by the facilitators. The participants were asked about their views on voluntary and compulsory ways of assessment and audit of green implementation in India. The findings of the workshop featured major challenges, drivers, initiatives, and the ways of effective implementation as well as enforcement on the discussed topic.
 
Article
This paper presents a new method for constructing metal domes. The method is basically one in which the whole structure is assembled initially at ground level in an essentially flat condition. By the use of posttensioning in an appropriate way, the space structure can be erected by deflecting into its final shape and into position. From the principle of deployable structures, this paper concludes that the basic problem of such a method is the geometric compatibility condition between the initial and final configurations. The geometric models that reflect the relationship between the planar layout and the space shape is established to describe the geometric compatibility condition of domes. An example of such deployable metal domes, taking into account the geometric models, mechanism condition, and appropriate posttensioning method, is given to illustrate the method. The finite-element analysis results of the example show that the proposed shape-formation method is feasible and the established geometric models are reliable. Potentially, this procedure can offer economics over traditional methods of construction of metal domes.
 
Article
Although computer analysis has created invaluable benefits in structural design, several structural experts have expressed concern about the impact of computers on younger engineers. Computers clearly helpdevelop insight into global-displacement patterns, but they may hinder development of insight into global-force patterns. The emergence of inexpensive computing time and automatic code checking makes itpossible to arrive at a design without assuming or investigating global-force patterns, focusing instead on member-level behavior. In the precomputer era, a designer was forced to think in terms of global-forcedistributions. However, this important design perspective will gradually disappear with the retirement of the last generation of designers educated in the precomputer era. To support this perspective in themodern design environment, the present paper introduces a computer-based tool to visualize global-force distributions in large structural systems. The tool is called the global force interpreter (GFI). This paperoutlines the approach to calculating and displaying force distributions and illustrates the tool on two example structures.
 
Article
The effects of wind on roofing systems are dynamic, because of wind's fluctuation in time and space. Therefore, a dynamic means of evaluating roofing systems is beneficial in identifying the component of the system that has the weakest resistance against wind uplift forces. The Special Interest Group for Dynamic Evaluation of Roofing Systems (SIGDERS) has commissioned a unique North American facility, which has been used to evaluate a mechanically fastened thermoplastic membrane roof system under three different test methods: the Factory Mutual FM-4470 static test standard, the European Union of Agreement (UEAtc) procedure, and the SIGDERS-developed dynamic load cycle. Comparison of the data from these tests shows that UEAtc and SIGDERS tests produce failure modes similar to those observed in the field. The SIGDERS load cycle is completed in much less time than the UEAtc procedure.
 
Article
Wind dynamics, on a conventional roofing system, lift the membrane and cause fluttering, introducing stresses at the attachment locations. To identify the component of the system that has the weakest resistance against wind uplift forces, a dynamic method of evaluating roofing systems is beneficial. A recent industry survey predicts significant growth for thermoplastic polyolefin (TPO) membranes. Among others, hot-air-weld ability is an advantage of the TPO. In mechanically attached TPO roofs, seams are formed by welding one side of the bottom sheet with the top sheet using hot-air machines. Advancements in welding technology have led to double-side weld procedures or encapsulated seams for the TPO membranes. Wind uplift evaluations are being carried out on the TPO systems with one-side weld and double-side weld. Experiments have been conducted at the dynamic roofing facility (DRF) of the National Research Council of Canada, using the SIGDERS (special interest group on dynamic evaluation of roofing systems) wind test protocol. Systems with double-side weld performed better than the systems with one-side weld. Use of double-side weld minimizes asymmetrical stress concentration and improves the wind rating of the mechanically attached TPO roofing systems.
 
Article
The project inception stage has been the focus of intense research activity for a number of years. The need to establish the project parameters and performance requirements has been an imperative in many organizations. Predesign processes and activities are being instituted that work through client strategic and organizational issues, needs, and requirements before the design team is involved. The participation of stakeholders in predesign workshops is a common feature of these project inception approaches. These approaches prepare a clear and workable statement of the project requirements in performance terms that the client group has agreed and committed itself to. This document can then provide a sound basis for the development of the design. One approach to these early stages of the project is strategic needs analysis. This approach uses a workshop setting to focus stakeholder involvement in proposing and identifying a range of strategic options for the proposed project. A case study of strategic needs analysis involving university faculty relocation to a new site is presented. The developments of organizational strategic options are described with the development of user performance indicators to guide the design development process.
 
Article
Innovative building conceptions, that allow for the change of the building's shape and form, can offer advantages for certain types of applications compared to conventional structures. The conception, design,and realization of transformable building structures require the use of innovative building technologies, and the development of new analytical methods and procedures. Geometric complexity is usually acharacteristic of the architectural expression of transformable structures, and their initial geometric configuration and representation is one of the earliest and most challenging phases in their design. A preliminaryinvestigation with computer simulation and animation studies can help identify problems in their initial geometric conception.
 
Article
This paper describes SEED-Layout, a module of SEED that supports the generation of schematic layouts of the functional units specified in an architectural program. SEED-Layout provides capabilities that allowdesigners to generate and evaluate rapidly different layout alternatives and versions; to explore the trade-offs involved; and to engage generally in an iterative, highly explorative design process. The resulting"design space" is complex, and the paper describes current efforts to provide designers with intelligent "navigation" aids that encourage them to explore interesting portions of this space without "getting lost."The paper concludes with a brief description of the current implementation and directions for future work.
 
Article
The largest tornado outbreak in the United States occurred on April 25-28, 2011. The outbreak resulted in widespread destruction across the southeastern United States and was responsible for over $5 billion in property loss. Although tornadoes cause significant damage every year in the United States, they are not currently included in building codes because the annual likelihood of an individual building being struck is quite small. However, catastrophic damage following large-scale tornado outbreaks has resulted in inquiry into the benefit of the use of stricter wind-design provisions in residential construction. Using the results of a fragility analysis based on the performance of a wind-induced vertical load path, property loss to wood-frame residential construction from tornadoes was estimated for residential buildings designed using locally adopted building codes at the time of the outbreak. The analysis was performed a second time, but this time using the stricter wind provisions of a state residential code applied across a portion of the southeastern United States. This allowed for an estimate of the reduction of property loss to wood-frame residential construction from large tornado outbreaks by using strengthened construction methodologies. Results indicate a reduction in residential property loss of up to 40% for the April 2011 outbreak.
 
Article
Technology has played a major role in the process of forming the architectural theory and practice during the twentieth century. The discourse on technology is well received both in hermeneutics and in architectural theory. What has been paid very little attention is how the notion has evolved and developed pragmatically. This paper will focus on the paradigm shift from the established ways of building on-site to the new methods of production of space off-site. The focus, however, is not the shift itself but rather how the destination paradigm has been comprehended and translated into practical solutions and how those solutions have established a dialogue with architecture both as a profession and as the final product. The milestone in this study is the Industrial Revolution, known as the architect of change in this transition. This paper does not provide a chronology of construction technology. By contrast, it focuses on the evolution both of the concepts from a semantic viewpoint and of the application from a pragmatic viewpoint in an international context.
 
Article
The paper shows the results of analyses of the behavior of an innovative subcomponent made of two glass shells and a plastic thermal belt interfaced with a resin-based adhesive, in order to define the plastic material–adhesive combination able to guarantee compliance with the requirements related to mechanical strength, thermoacoustic insulation, dimensional stability, material compatibility, and durability. Two different types of ultraviolet (UV)-curing adhesive were used to establish the best plastic–adhesive combination. A study of the mechanical behavior and the reliability over time of the bonded assembly was conducted by performing accelerated weathering tests and tensile tests on 30 specimens. The laboratory tests were performed using single-lap-joint specimens in accordance with the ASTM D1002, ASTM D3163, and ISO 4587:2003 standards. At the end of the accelerated weathering tests, it was possible to observe that the stress conditions simulated during the seasonal cycle inside the climatic chamber led some specimens to failure, without affecting others. To quantify, in real terms, the performance of the two analyzed adhesives over time, it is necessary to expose new specimens to the natural weathering effects induced by the environmental conditions for a duration of at least 1 year. Future studies would be useful for exposing new specimens to new seasonal cycles developed using the parameters of different climatic contexts than those used until now. This paper demonstrates the use of an innovative resin-based adhesive for gluing plastic and glass subcomponents together.
 
Article
Air leakage through recessed lighting fixtures has been identified as a common issue that causes extra energy consumption in residential buildings. However, few quantitative studies in this area were found. As such, a preliminary assessment of the magnitude of this type of energy loss was conducted by using three-dimensional (3D) transient computational fluid dynamics (CFD) models. A hypothetical layout of recessed lighting fixtures was designed with boundary conditions of four different seasons, which were obtained from recorded roof/attic temperature data sets. The results of the study indicate that leakage of recessed lighting fixtures could be a significant channel of energy loss in such attic-related residential buildings, especially in the summer and winter.
 
Optimal Combinations of Variables in Each of the Four Main Orientations (Data from Pushkar 2007) 
Article
For environmental evaluation of building operational energy, greenhouse and acidic gases are typically used as appropriate measures. This approach can lead to the loss of additional information concerning other carbon fuel-relevant impacts, such as carcinogenic substances, fossil fuels, and land users. The objective of this study is to analyze three different environmental levels of evaluation: (1) carbon dioxide (CO2) emission (inventory), (2) environmental impacts (midpoint), and (3) environmental damage (endpoint). A simple building module (3×4×3m) facing east, north, south, and west was studied. Eco-Indicator 99 (EI99), a comprehensive damage-oriented lifecycle impact assessment method, was used. Coal was the primary fuel used for electricity production. For each of the three evaluations, an unpaired two-tailed t-test was used to determine the differences between all pairings of the module in the four cardinal orientations. On the basis of inventory and midpoint evaluations, separate optimization of building technology variables is required for each of the cardinal directions; these results were not confirmed by endpoint evaluation. The study informs designers regarding the appropriateness of midpoint evaluation of EI99 (in addition to the CO2 measure) and the need for operational energy consumption to be evaluated from an environmental point of view.
 
Article
The primary advantage offered by the Eco-indicator 99 (EI99) methodology is its ability to consider life cycle assessment (LCA) uncertainties. EI99 considers these uncertainties through a perspective-specified set that includes egalitarian/egalitarian (e/e), hierarchist/hierarchist (h/h), and individualist/individualist (i/i) methodological options, along with a perspective-averaged set that includes individualist/average (i/a), egalitarian/average (e/a), and hierarchist/average (h/a) methodological options. These two sets of options are based on a cultural theory framework that was initially intended for different areas of interest. The objective of this study was to determine the robustness of EI99 for the environmental evaluation of building technologies under LCA uncertainties. A split-unit design was used to determine the robustness of EI99 for evaluating four reinforced concrete technologies and four masonry structure technologies. A significant disordinal interaction was observed between the two methodological sets evaluated by EI99. The h/h and h/a options were considered to fall within the same area of interest. Different rankings for the building technologies were obtained using the different EI99 methodological options. A full set of EI99 methodological options should be used by building designers and practitioners to determine the impact of a preferred decision on the initial construction cost, the life-cycle cost, the embodied energy, occupant health, and resource and/or habitat conservation.
 
Article
In recent years, depleted resources and environmental concerns have stimulated research in renewable and recyclable materials for particleboard production. This paper presents the research work on the production of particleboards using maize (Zea mays) cobs, rice (Oryza glaberrima) husks, and groundnut (Arachis hypogaea) shells, which are abundantly available as agricultural residues. The goal of this project was to study the feasibility of medium-density particleboard panels made of agricultural residues for use as internal partition wall cladding in residential buildings. The panels of densities between 600 and 900 kg/m3 were produced using a natural-based adhesive from acacia mimosa tannin extract and hexamine. Some other parameters like the moisture content (after adhesive application) and the press temperature were varied during the production so as to investigate their effect on some mechanical and physical properties like internal bond strength, bending modulus of rupture, swelling, and hardness. The mechanical properties of rice husk- and groundnut shell-derived particleboard failed to satisfy European standard requirements in terms of bending strength; those made of maize cobs achieved the specifications but at a higher density compared with common wood-based particleboard. The swelling behavior did not meet the standard for use in wet areas. The particle geometry and size as well as the board structure did not compare well with the properties of the wood-based materials, but the products from those residues do hold promise for use as nonload-bearing members. On the side of rice husk and groundnut shells, alternate areas of application such as thermal insulation and decorative cladding materials could be contemplated.
 
Article
In most developing countries with a tropical climate, the benefits of insulating external masonry walls are often overlooked, and there is little or no effort to reduce the energy consumed. Apart from the comfort challenges, there is a concern of increasing energy consumption due to the rise in air temperatures and air-conditioning loads in building. Because building walls constitute the largest part of a building, there is a need to design sustainable building walls that can bring about energy efficiency and reduce cooling load by using the approach of wall insulation. Hence, this study involved the use of coconut-fiber insulation to achieve energy efficiency and thermal comfort in residential dwellings. Coconut fiber is a by-product from other industries and can be used for thermal insulation by placement in the cores of masonry block walls (i.e., as a loose-fill insulator). As such, an experiment was set up to estimate the effect of using coconut fiber-insulated masonry walls to achieve energy efficiency and thermal comfort in residential dwellings. The experiment made used of two identical physical small-scale envelope models to investigate the effects of using coconut fiber-insulated masonry walls. During the testing, the walls of the two models were insulated with coconut fiber as well as fiberglass board to determine their thermal benefits. Coconut fiber was found to be the preferred insulator because it has the required attributes to maintain thermal comfort and improve the energy efficiency of residential dwellings. The results also show that coconut fiber was able to improve the energy efficiency of the envelope physical models. This application is intended for low cost-residential buildings in a hot, dry climate.
 
Article
Charrettes are collaborative, interdisciplinary workshops commonly used in the programming and or design phases of sustainable building projects and often utilized in Leadership in Energy and Environmental Design (LEED) projects. Charrettes are implemented to increase collaboration and communication across diverse building professionals and stakeholders. However, minimal empirical research documenting the outcomes or impact of charrette processes or identifying whether specific charrette characteristics or combinations of characteristics actually contribute to an overall increase of LEED points exists. The purpose of this research project was to research salient characteristics of charrette processes and to observe their impact on the LEED points achieved. Methodology included a focus group of nine building professionals and a survey of 66 building professionals who had participated in a LEED-certified project(s). Characteristics derived from the focus group discussion were used to develop the survey instrument. Implementing at least one charrette during a project was shown to increase the LEED points achieved by an average of seven points. Three charrette characteristics, however, were shown to reduce the magnitude of positive impact. Specific characteristics to avoid are (1) holding a charrette as a LEED strategy or LEED checklist meeting; (2) having a defined or structured agenda; and (3) having project goals already defined prior to the charrette(s) taking place. Overall, results suggest the charrette process has the potential to provide significant benefits, but to fully realize such a benefit, the charrette should not include factors that limit a group's ability to produce creative ideas, goals, and innovative solutions.
 
Article
Nonstructural systems are responsible for the majority of national loss suffered during earthquakes, and suspended ceilings with acoustic lay-in tiles are among the most significant - and most vulnerable - of these nonstructural systems. Expensive full-scale experimental shake table tests are generally preferred over mathematical modeling techniques for simulating the seismic performance of these suspended-ceiling systems. Because of this traditional reliance on shake table testing, there is currently no experimentally validated finite-element model of suspended-ceiling systems. This paper addresses this crucial knowledge gap by introducing the first experimentally validated computer simulation of suspended-ceiling systems and by establishing a modeling methodology for future numerical studies. This study is the first to use finite-element modeling for a heterogeneous system (in this case, ceilings composed of loose components). This project aimed to develop (1) the feasibility of combining finite-element modeling of suspended-ceiling systems with current seismic simulation tools; (2) a system for validating the numerical model of the suspended ceiling with system-level shake table tests; and (3) the possibility of using the validated numerical model as a substitute for expensive shake table tests.
 
Article
Cross-laminated timber (CLT) is composed of a series of lumber layers placed orthogonally to create a thick panel. Advantages of CLT construction include reduced construction time, lighter structural elements, and reduced carbon footprint. As part of an effort to explore the use of a southern pine CLT panel for building code acceptance, the transmission loss (TL), associated sound transmission class (STC), normalized impact sound pressure levels (NISPL), and associated impact insulation class (IIC) of CLT walls and floors were measured. Wall and floor configurations were tested both as bare CLT panels and with one side covered with studs/joists, insulation, and gypsum wall board. STC results of the bare wall and floor configurations produced identical STC values. The wall and floor configurations using CLT with one-sided studs/joists met or exceeded the STC values in the International Building Code (IBC), but did not meet the IIC values in the IBC. Comparisons of the one-third octave band TL of the CLT panels with conventional wood frame and concrete sections were discussed. The TL performance of the CLT panels mirrored the mass–law relationship. The NISPL associated with CLT bare floors mimicked the NISPL values of a bare concrete floor, except at higher frequencies at which the CLT outperformed the concrete.
 
Article
This article presents a simple linear damage accumulation model that may have applicability for predicting damage from sustained winds in double-sided acrylic foam tape used to attach curtain wall glazing panels to buildings. The purpose of this model is to investigate the possible cumulative effects of years of wind-induced stresses that are less than the peak stress expected during a 3-s gust, as specified in current design guidelines established by the structural glazing industry and adopted by the manufacturer of these structural glazing tapes. Several representative wind histories are selected to provide input data for the model. These wind histories provide multiple years of average wind speeds over either 10-min or 1-h recording intervals, depending on the source. Each entry in a wind speed history is converted to stress on the glazing adhesive tape on assumed window dimensions using the standard wind loading design equations of ASCE 7-05. A creep rupture prediction equation, developed from a creep rupture master curve obtained by experimentally evaluating 3M VHB G23F acrylic foam tape, provides the time to failure as a function of applied tensile creep stress. Using a linear damage accumulation model, fractions of life used at each entry are combined into a total percentage of life used. Based on evidence that cyclic loading may be less significant than sustained stress events, the effect of cyclic fatigue was not considered in this study. The model developed does not provide evidence that the industry established design procedure is unsafe using the selected wind speed histories, provided sufficient safety factors are used. The model does suggest, however, that the accumulation of damage from sustained wind speeds, especially winds from storm events, could present a mode of failure that merits examination along with the more traditional peak wind speed design procedure currently in use by the structural glazing industry and employed by the vendor. The approach may have applications for other time-dependent glazing sealants as well.
 
Article
The primary goal of this paper was to answer the question: Do empirical data from real-world projects align with Design for Adaptability (DfA) strategies reported in the literature? The data and analysis presented herein suggested that when DfA strategies are present in building design (intentionally or otherwise), they indeed facilitate adaptation. Similarly, when the strategies were not present, the adaptation project was impeded. DfA strategies can contribute to circular economy by designing today’s buildings with the potential to be modified for future needs. Thus, DfA embraces the inevitability of change and allows buildings to be revitalized according to society’s evolving needs and wants. While previous journal papers, books, and design guides on this topic were based on theoretical reasoning, expert opinion surveys, practical experience, and case studies, the current paper contributed to the discussion by comparing DfA strategies from the literature with empirical data from 89 real-world building adaptations. Data were provided by 76 industry professionals and included short descriptions of the buildings’ physical features that facilitated or impeded the adaptation projects. A thematic analysis method was used to evaluate the data. Finally, the research provided practical steps for implementing adaptable design: quality documentation, open floor plans, large floor-to-floor heights, and simple designs.
 
Article
Industrial building systems (IBS) are considered a modern method of construction (MMC). Although numerous studies have explored the implications of IBS implementation, they have focused primarily on the hardware elements. This study investigated the adaptability of IBS components and suggested improvements for the construction industry. The main objective was to capture the Malaysian construction industry's perception of IBS by using a quantitative approach. A survey was conducted to collect the viewpoints of professional architects, civil engineers, and quantity surveyors who worked as IBS consultants, contractors, manufacturers, and expert academics. The results of the survey indicate that the respondents agreed that the most critical issues in IBS construction were design conflicts and skill shortages. These responses were consistent across the professions. Furthermore, the respondents believed in the importance of preparing detailed information about the components and connections, applying standard connections, and encouraging innovative designs to resolve the existing issues. The results of this study have implications for designers, engineers, and consultants because they lay the groundwork for a theoretical framework for producing and using adaptable IBS components in the construction industry.
 
Article
Engineering design review is the process of assessing a design against codes and standards requirements to validate the accuracy and quality of the design and detecting problems before manufacturing and assembly begin. Building design regulations are normally in the form of texts, charts, tables, and mathematical expressions. These regulations and guidelines usually have legal status. Nevertheless, the cognitive and logical ability of the people is dissimilar to anything executed in computing machines. Consequently, the computerization of this process represents an actual challenge to the architecture, engineering, and construction (AEC) industry. Most of the cited methods for automated rules compliance auditing are either based on proprietary, domain-specific, or hard-coded rule-based representations, which may be useful in their specific applications. However, these methods have the disadvantages of being costly to maintain, cumbersome to modify, and lacking a comprehensive schema of rules and regulations modeling that can adapt to different domains, and thus don’t support an open data standard. They are often denoted as black box or gray box methods. This work offers a new comprehensive framework that reduces the deficiencies of the current approaches. The primary goal is to tackle the problem by concentrating on establishing a generalized adaptive framework (GAF) for a neutral data standard [such as the Industry Foundation Classes (IFC)] that enables automation of building design review processes to achieve design accuracy and efficiency.
 
Article
This study focused on lifecycle assessment (LCA) and evaluation of the sustainable performance of structures retrofitted by adding stiff diaphragms or by using seismic isolation systems. To analyze the mitigation measures, methodological options addressing LCA uncertainties were used. For this purpose, a two-stage, nested, mixed, and balanced ANOVA test was applied. The following four cases were evaluated: nonretrofitted building (baseline), use of concrete diaphragms for strengthening, application of high-damping rubber bearings, and use of seismic isolation columns. Four natural ground-motion records were used for analysis: El Centro, Kobe, Hachinohe, and Northridge. The reduction in environmental damage, relative to the nonretrofitted alternative, was evaluated. It was found that the environmental impact of the four mitigation measures was approximately 10% of the total building impact. According to the results obtained in the frame of the present study, the use of seismic isolation columns resulted in damage reduction of approximately three times more than that achieved by high-damping rubber bearings.
 
Article
Accommodating the preference of the growing elderly population to age independently, at home and in the community, requires innovative and cost-effective neighborhood retrofit plans. Retrofitting existing homes and infilling available neighborhood land parcels with "smart homes", equipped with technologies that enable monitoring and assessment as a means of ensuring the quality and efficiency of home care and health care provision, is intrinsic to these efforts. Blueroof Technologies, Inc., in McKeesport, Pennsylvania, has developed and demonstrated a number of in-home and neighborhood-scale technologies and is working with the local McKeesport municipality to restore an economically distressed neighborhood to accommodate successful aging in place. This paper describes the Blueroof "BlueNode", "BlueKiosk", "Smart Cottage", and "McKIZ", a McKeesport neighborhood restoration initiative, which incorporates the use of smart cottages and neighborhood-scale interventions to address the housing challenges of an aging population. The technologies and neighborhood retrofit methods described in this paper could serve as a cost-effective template for restoring low- to middle-income neighborhoods to enable successful, mixed-generation aging in communities domestically and abroad.
 
Article
There is a substantial body of literature linking energy efficiency to occupant behavior. This paper extends that literature by developing a process for segmenting U.S. homeowners into profiles, on the basis of their (1) level of utility-bill botheredness and (2) household budgetary constraints. This process, using these two lenses to view homeowners, is hereafter called Decision-Ade. It builds on and contributes to theoretical knowledge in the areas of (1) residential energy decisions, (2) marketing science, (3) the psychology of behavior change, and (4) emotional response modeling. The motivation for developing Decision-Ade is to understand whether utility-bill botheredness and budgetary constraints can be used to segment U.S. homeowners into unique groups, which in this paper are referred to as profiles. The empirical analysis confirms that homeowner segmentation is not only made possible through this process, but that it enhances the understanding of how homeowners make decisions regarding upgrades to their homes. A compelling aspect of this study is that its sample comprises more than 1,000 U.S. homeowners, which is a sample size larger than nearly each of the studies reviewed for this paper. By using a sample of this size, this methodology can be applied to other fields as well, providing information that advances basic knowledge and capabilities across multiple disciplines.
 
Article
This research evaluated and compared the wind-uplift capacity of wood roof-sheathing panels fabricated by using nails with retrofitted roof panels made with nails and closed-cell sprayed polyurethane foam (ccSPF) adhesive. In hurricane-prone areas, structural retrofits of light-framed wood roof structures are needed to mitigate wind damage to existing residential roof structures because the majority of these have inadequate design strength to resist hurricane-force winds. A steel pressure chamber connected to a pressure loading actuator was used to conduct uplift pressure tests on 186 roof panels. The panels were fabricated using 11.1mm (7/16in.) thick oriented strand board sheathing fastened to nominal 51 by 102mm (2 by 4in.) southern yellow pine framing members spaced 610mm (24in.) apart. There were 123 panels tested in typical as-built conditions, and 63 panels tested after they were retrofitted with ccSPF. The parametric study determined the effect of several factors on wind-uplift failure pressure: (1)three nail types, (2)two nail spacings, and (3)three retrofit methods using ccSPF. The hypothesis tested was that ccSPF (traditionally used as wall and roof insulation in houses) could also act as a structural adhesive to increase the wind resistance of existing roofs. Standardized tests do not currently exist for wood roof panels, and so a uniform, static pressure-test protocol was developed on the basis of the ASTM E330, Method B Test Procedure. The results showed that ccSPF retrofits increase the wind-uplift capacity of the pre-1994 code-minimum wood roof panels by as much as 250-300%. This finding is important because it could provide a means to improve the wind resistance of these older roof designs, which may still account for more than 60% of the existing residential inventory. The distributions of roof-failure capacities of as-built and retrofitted roof panels are presented, and statistical parameters are presented for use in developing performance-based design criteria. The documentation and approach is presented as a model test protocol as the basis of a standardized wind-uplift test method for wood roof-sheathing panels.
 
Top-cited authors
M. G. Matt Syal
  • Michigan State University
Robert Mark Lawson
David Arditi
  • Illinois Institute of Technology
Chimay J. Anumba
  • University of Florida
Paul Kremer
  • Iowas State University