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The global surge in environmental pollution, largely attributed to industrialization, has fueled a pressing need for sustainable solutions. In response, the construction sector is increasingly focusing on bio-based materials such as hemp, recognized for its low environmental footprint and prominent carbon-negative quality. As designers, housebuilders, and an environmentally conscious society pivot towards ecological alternatives to standard building materials, hempcrete emerges as a promising candidate. As a composite material mainly made from hemp hurd/shiv, water, and lime, hempcrete offers the ability to sequester carbon long after its incorporation into structures. As a result, the hemp cultivation process—which can be completed within less than four months—ensures that more carbon is absorbed during production and deployment than emitted, e.g., per one study, sequestration on the order of 300 kg of CO2 per m3 of hempcrete. In comparison to concrete, hempcrete offers a more sustainable footprint, given its recyclability post life cycle. This state-of-the-art review paper delves deep into different aspects of hempcrete, summarizing its multifaceted attributes, particularly its compressive strength. Based on the study conducted, the paper also suggests strategies to augment this strength, thereby transitioning hempcrete from a non-load-bearing material to one capable of shouldering significant weight. As architects and designers consistently strive to align their projects with high ecological standards, focusing not just on aesthetic appeal but also environmental compatibility, hempcrete becomes an increasingly fitting solution for the future of construction. [ABSTRACT FROM AUTHOR]

Many elevated houses in coastal areas have suffered serious wind-induced damage during hurricanes; this indicates the need for better understanding of the performance of elevated homes subjected to higher wind forces or effects in open pile-supported areas. The actual direct and indirect wind-induced damage to elevated wooden residential houses in past hurricanes is briefly reviewed. Computational fluid dynamics (CFD) analysis was utilized to investigate the effect of wind angle and house elevation on the magnitude of mean negative or positive design pressures as an important variable affecting the vulnerability of the structural system. The numerical results were validated based on available experimental tests in terms of the mean pressure coefficient (Cp) over the house surfaces. The CFD results show that elevating a house can result in increased wind speed and subsequent additional turbulence effects around the house, in particular at the exposed underside. The results indicate that elevating a house does not significantly affect the Cp distribution on the roof surfaces, so that the roof uplift forces remain almost constant. However, elevating the house leads to increases in Cp at various rates over the house surfaces, including exterior walls and along the underside. The rates of such increases depend on wind direction and house elevation. Regardless of wind direction, the overturning moment acting on an elevated 1:20 scale house increases about 50% and 95%, respectively, for 0.105 and 0.21 m elevations. Considering the scope and the limitation of the study presented in this paper, more studies are needed to better understand the effect of aerodynamic characteristics of elevated houses, particularly on peak positive or negative pressures over various building surfaces. [ABSTRACT FROM AUTHOR]

Coastal residential buildings have suffered significant damage during recent hurricanes, which illustrates the poor performance of coastal structures. This paper reviews the performance of coastal residential buildings with respect to direct and indirect damage, and subsequent mitigation techniques are discussed according to hurricane wind and flood-related hazards. The results show that building systems other than conventional wood frames have better performance during strong hurricanes. Regardless of building materials and systems, envelope systems and roofs are more susceptible to wind-induced damage compared to structural components. Therefore, selecting adequate connection systems, suitable wind-resistant materials, and appropriate installation methods for wall/roof coverings can significantly reduce the level of wind-induced damage. Regarding flood-related hazards, surge and subsequent wave heights cause inevitable damage to nonelevated or low elevated buildings once a flood reaches the first-floor level. Furthermore, many elevated buildings surviving a flood can still be vulnerable to wind-induced damage, particularly envelope systems due to the fact that the house would be exposed to higher wind pressures. As a result, selecting the appropriate foundation system and using flood-resistant materials below the base flood elevation can reduce flood-induced damage to residential buildings in coastal regions. [ABSTRACT FROM AUTHOR]

• Earthen materials are eco-efficient & sustainable that can be used for home construction. • Hempcrete can be integrated with subsoil and lime to create load-bearing structures. • 3D printing offers sustainability benefits by reducing reliance on wooden formwork. • Dome-shaped houses excel in resisting compressive stress and are ideal for earthen homes. • Cob, hempcrete, & bamboo through 3D printing provides a sustainable home construction. Earthen materials are considered as one of the oldest materials in home building on the planet. Earth-based building materials are eco-efficient, sustainable, renewable, recyclable, and carbon-zero or even carbon-negative materials for the case of hempcrete. Earthen building materials are used together with bamboo to enhance the strength of the structures. Bamboo has been used for centuries as a central pole or frame of the house to support the structure and the walls. The use of green materials in construction is becoming highly desirable since it helps reduce the environmental impact during construction and use phases. Not only the use of material, but also the method of construction highly impacts the sustainability of home building. The construction method of 3D printing reduces the use of wooden formwork, and this can help reduce or eradicate deforestation. The use of clay and earthen materials for 3D printing has recently gained attention due to its low environmental impact in comparison to concrete. With the current high demand of using earthen materials with the interest of modernizing the material mix, construction methodology, and geometry usability, relevant theoretical and experimental studies are necessary. The main goal of the research presented in this paper is to discuss the previous experimental literature on cob, hempcrete, and bamboo components for home building and identify the necessary requirements needed for transition toward 3D printing. [ABSTRACT FROM AUTHOR]

Abstract Building Information Modeling (BIM) initially emerged as a capability to transfer information and allow interaction or interoperability of various software tools used for architectural, structural, mechanical, electrical design, and building construction. Its application from developing 3D models, structural analysis, cost estimation, and mechanical analysis has now expanded to other applications such as energy simulation. Multiple computer-aided design (CAD) tools work as BIM authoring tools to generate BIM files in different formats containing various types of building information. In addition, there are various building energy modeling (BEM) tools capable of importing these BIM files to perform energy simulation. However, such tools have various capabilities and limitations and need to be investigated and categorized in order to facilitate choosing a proper tool for design professionals in different phases of project and purposes. In addition, interoperability and data exchange issues between BIM and BEM tools should be understood in order to find solutions such as developing proper corrective middleware tools to rectify them. This paper reviews the challenges, issues, and shortcomings in BIM-to-BEM interoperability process (BBIP) by proposing a detailed classification for these issues and studying the available solutions. The paper also explains how a corrective middleware, which is developed by the authors using Python, can be utilized to modify a gbXML file prior to adoption in energy simulation to resolve the issues related to building envelope in BBIP. To do so, initially a review is presented on research studies focused on different types of BIM schemas such as IFC and gbXML and energy simulation tools capable of reading these files such as Green Building Studio (GBS), DesignBuilder, Integrated Environmental Solutions-Virtual Environment (IES), and OpenStudio. In addition, some of the challenges in the application of BIM for energy simulation such as interoperability issues, lack of standards, and lack of easy solutions for extending existing BIM schemas and available corresponding solutions are also reviewed. With the focus on building envelope in mind, three case studies are discussed to observe the challenges and issues with respect to BBIP using Revit, GBS, and OpenStudio. Moreover, these case studies provide an opportunity to investigate the application of corrective middleware tools similar to what is developed in the study presented. Highlights • A brief review of Building Energy Modeling (BEM) tools is provided • Building Information Modeling (BIM) file types are reviewed and compared • Existing challenges, issues, and shortcomings in BIM to BEM interoperability process (BBIP) are identified • Existing solutions for issues in BBIP are reviewed and a corrective tool is developed and proposed to solve issues related to gbXML files involved in BBIP • A comprehensive categorization is proposed for issues in BBIP. [ABSTRACT FROM AUTHOR]

Highlights • The study shows that the dynamic models are validated by steady-state analysis in hot box test, and therefore applicable for the measurement of R-value. • The dynamic models show reasonable results. When the temperature difference is above 20°C, the R-value calculated by the dynamic models shows a percentage difference lower than 7% compared with the steady-state analysis. • The measured R-values show a noticeable difference compared to the design R-value. Therefore, experimental measurement for building envelope systems is desired to get the real performance when energy simulation is performed. • Among the three dynamic models explored in this study, the 3R2C model shows the best accuracy. • The use of dynamic models is recommended for the measurement of R-value, especially when the environmental condition is hard to maintain stable. Abstract This research mainly focuses on the experimental setup of the Hot Box Test Method and comparison of different models for measurement of thermal properties of building envelope systems. Hot Box Test Method has long been used to determine the thermal properties of building envelope systems, however, the steady-state assumption for calculation is not always desired, especially when the environmental conditions cannot be controlled. To utilize models considering the dynamic behavior of buildings for in-situ measurement, it is desired to first validate such models and compare the performances with hot box test. Therefore, the performances of several dynamic models, including Anderlind's Regression Model and R-C Network Model, have been studied. Hot box tests were performed in the Building Enclosure Testing Laboratory (BETL) at Penn State University and the results show the 3R2C model turns out to be the most accurate one among the dynamic models explored in this study. With a temperature difference larger than 20 °C, all dynamic models are validated with a percentage difference lower than 7% compared with the steady-state analysis, giving us alternatives for R-value measurement when in-situ measurement condition are applied. [ABSTRACT FROM AUTHOR]

Structural design/analysis is one of the most needed uses of Building Information Modeling (BIM). Transforming a building information model to an engineering analytical model is tedious and time-consuming. In addition to geometry transformation, extensive modifications and interpretations are required to make the complex transformed model ready for analysis. Despite such a recognized need, Industry Foundation Classes (IFC) has not been developed sufficiently in engineering analysis uses of BIM as much as it is in some other uses such as design coordination and facility management. As a contribution to addressing this void, development of a new mechanism is discussed in this paper for transformation of IFC building information models in the Coordination View to their equivalent structural models in IFC Structural Analysis View. Considering IFC as the input and output file formats of the mechanism significantly increases the level of interoperability in the proposed model interpretation process. This mechanism is designed to automate the required transformation, modification, and additions operations during such information exchanges. To illustrate feasibility of its implementation, a tool is introduced to automate the developed Interpreted Information Exchange (IIE) mechanism, and its application through a case study serves as validation of the mechanism. The designed IIE mechanism can be extended to automate additional structural modeling tasks. The IIE concept is also applicable to other uses of BIM, especially engineering analysis uses, in order to automate creation of analytical modeling from building information models. [ABSTRACT FROM AUTHOR]

Buildings contribute to about 40% of total annual energy consumption in the U.S. and saving a small percentage of that can lead to significant economic and environmental impacts. Building Energy Modeling (BEM) tools are important in reducing building's energy consumption. Most of the available tools only provide total energy consumption related to HVAC system, lighting, hot water, and appliances. While fine-grained data may be available in some computer tools, the process for obtaining these data is time-consuming, error-prone, and requires software-related skills. This paper explains a developed tool that contributes in automation of building energy simulation and providing fine-grained outputs by using Building Information Modeling (BIM) and modified source code of energy simulation tools such as EnergyPlus and OpenStudio. This tool, which is referred to as ABEMAT (Automated Building Energy Modeling and Assessment Tool), receives gbXML file and provides users with the amount of heat transfer through every single building envelope component such as windows, doors, and walls through an automated process. ABEMAT's and EnergyPlus advanced outputs are compared for validation; the latter being a time consuming process and error-prone, which requires software-related skills compared to ABEMAT. Results showed similar findings indicating the functionality of ABEMAT in providing fine-grained outputs. [ABSTRACT FROM AUTHOR]

Building Information Modelling (BIM) has significantly facilitated information management and collaboration in construction projects. During the past two decades, many information standards such as Information Delivery Manuals and Model View Definitions (MVDs) have been developed to enhance interoperability among construction-related tools. The focus of these standards has mainly been on conventional construction. In this paper, differences in the data structure of these two types of construction-related tools are discussed and compared with the current MVD standards. This study shows that the existing standards cannot fully support multi-storey modular buildings. By development of a product architecture model and comparing it with the data structure of current MVDs, it is concluded that available standards can be modified to support both modular and site-built constructions. In this paper, essential MVD concepts required for such extensions are presented. Through a case study, the developed concepts are applied to the currently available architectural-to-structural MVDs in order to create architectural to structural design/analysis MVDs for application to multi-storey modular buildings. The case study shows that using the presented concepts, an existing MVD can be extended to address special needs of multi-storey modular building projects as well as conventional construction. [ABSTRACT FROM PUBLISHER]

During the past decade, building information modeling (BIM) has significantly influenced the construction industry. However, none of the available BIM tools and frameworks focuses on modular construction as an industrialized type of construction; thereby, implementation of BIM in these projects is relatively more challenging compared to site-built constructions. In this paper, an information delivery framework is presented for multistory modular buildings that can address both the project-based and product-based nature of these buildings. To develop such a framework, an extension to an already-existing information delivery manual development methodology is proposed in this paper. The extension makes it possible to capture the hierarchy of the building components, which is an important characteristic of modular buildings as manufactured products. This is done by integrating a new component known as a product architecture model (PAM) with other components of the framework in order to capture the information related to industrialized product-based nature of these buildings. This paper reports the extended methodology and frameworks developed using this methodology for multistory modular buildings. The resulting framework is validated by considering a typical modular building project in the United States and comparing its information flow with the framework. The paper also discusses additional potential contributions of the work such as outlining a baseline to extend the industry foundation classes (IFC) data schema and enable it to model specific elements of modular buildings. [ABSTRACT FROM AUTHOR]

Transforming a building information model to an engineering analytical model is tedious and time consuming. With the current state of interoperability, after importing the building information model, the designer makes extensive modifications to prepare the model for analysis. This issue could be addressed by automating the model transformation process. In this paper, an automated interpretation mechanism referred to as interpreted information exchange (IIE) is presented and compared with the conventional direct information exchange (DIE). Moreover, a methodology is proposed for design and standardization of this type of information exchange to facilitate its implementation. Subsequently, application of IIE for engineering analyses is illustrated by explaining and validating a case study platform developed for interpreting the structural analytical model from the architectural model. Furthermore, based on the experience gained as a result of developing this tool, the considerations that need to be taken in the design of an IIE process are specified. Finally, the paper suggests how IIE can facilitate using building information modeling (BIM) for engineering modeling purposes. [ABSTRACT FROM AUTHOR]

The modular building construction method is the industry's effort for industrialization of building construction. Similar to other types of production, a product information model is required for lifecycle information management of modular buildings. In this research, the mutual hierarchy of typical multistory modular systems is identified and represented in a product architecture model (PAM). This provides the industry with an information model required for industrial design of this type of construction. Since modular construction is neither as heavily project-based as conventional construction methods nor as significantly mass-produced as manufactured products, none of the current in- formation management frameworks in manufacturing and construction industries are necessarily capable of addressing the needs of such projects. In the research reported here, this need is addressed by development of a product PAM for the most conventional modular systems. The PAM represents the hierarchy of modular building components along with their interactions, functionality, and attributes. This paper initially reviews major types of modular systems, and then focuses on the development methodology, validation, architecture, and content of the PAM. This is followed by an explanation of its different uses, including extension of the current construction industry's information management frameworks and platforms such as building information modeling (BIM) to support modular construction and providing a basis for product-base design of such buildings. [ABSTRACT FROM AUTHOR]

3D-printing has been growing in acceptance in the construction industry owing to its transformative potential in concrete materials. One of the main challenges for its further adoption is the integration of reinforcement given the difficulty of incorporating steel rebars and the formation of cold joints between filaments. This study proposes the use of barbed wires, fencing wires with sharp thorn-like projections, as a reinforcing component to improve tensile capacity and bond between printed filaments. Results indicated that incorporating barbed wire into 3D-printed concrete increases overall mechanical performance (e.g., moment capacity and bond strengths up to 363% and 71%, respectively, compared to plain 3D-printed concrete). This improvement can be attributed to the twisting of wires and the unique geometry of the 4-point barbs. The proposed barb-wire reinforcement method demonstrates the feasibility of in-process reinforcing during 3D-printing and can be further advanced to achieve full automation of the printing and reinforcement processes. • A novel reinforcement approach of using barbed wires in 3D-printed concrete is proposed. • The barbed wire inclusion offers excellent potential to enhance the tensile capacity of printed components. • The wire protrusions in barbed wires act as a ribbed surface on the steel rebar and enhance the bonding between reinforcement and concrete. • The pull-out test results indicate the strong bonding between barbed wires and concrete to prevent slip and offer full reinforcing capacity. [ABSTRACT FROM AUTHOR]

The authors present the results of a feasibility study to apply the major steps of the methodology to quantify seismic performance factors (SPFs) for structural insulated panels (SIPs) as the seismic force-resisting system for residential and light commercial buildings. This methodology uses collapse evaluation to determine acceptable SPFs. Structural response prediction was assessed through the combination of building code seismic provisions, nonlinear dynamic analyses, and risk-based assessment techniques. The SIP system in this study consisted of a rigid foam insulation core sandwiched between two sheets of oriented strand board. Analytical modeling was carried out using seismic analysis software. The results of the preliminary study show that the methodology and the seismic analysis software used in this study can lead to the determination of SPFs for SIP systems, but extensive experimental test results among other data are needed for a comprehensive project to quantify SPFs. [ABSTRACT FROM AUTHOR]

This research formulates a closed-form equation to predict a glass panel cracking failure drift for several curtain wall and storefront systems. An evaluation of the ASCE 7-10 equation for Dclear, which is the drift corresponding to glass-to-frame contact, shows that the kinematic modeling assumed for formulation of the equation is sound. The equation proposed in this paper builds on the ASCE equation and offers a revision of that equation to predict drift corresponding to cracking failure by considering glazing characteristics such as glass type, glass panel configuration, and system type. The formulation of the proposed equation and corresponding analyses with the ASCE equation is based on compiled experimental data of twenty-two different glass systems configurations tested over the past decade. A final comparative analysis between the ASCE equation and the proposed equation shows that the latter can predict the drift corresponding to glass cracking failure more accurately. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the most current topics of interest related to the field of housing and residential building construction. It addresses issues related to industry-wide residential construction trends, policies, innovative technology adoption, construction management, sustainability, energy efficiency, building science, and the need for education, especially regarding architectural concerns. The authors discuss several key technical aspects of residential building, such as structural concerns, building enclosures, and indoor environmental quality issues. Emphasis is placed on the need for renewed research and development efforts, outside-the-box thinking related to financial and investment structures for housing, improved models for adopting innovative technologies in residential construction, new construction management approaches, incorporation of more advanced building science in conjunction with advanced engineered features and architectural design, embracing green and sustainable design and construction, and consideration of the health of the occupants. The authors, who have varying specialties, identify critical issues that need more investment to support technical studies and developments as well as education, training, and awareness efforts. [ABSTRACT FROM AUTHOR]

This state of the art review paper aims to discuss the results of a literature survey on possible ways to reinforce printed concrete based on existing reinforcement strategies. Just as conventional concrete, for 3D printed concrete to be suitable for large-scale construction, reinforcement is needed to increase the tensile capacity of concrete members and reduce temperature and shrinkage cracking. Despite efforts that are currently underway, the development of proper reinforcement suitable for printed concrete is still very active on the research agenda. As an initial step for designing suitable reinforcement for printed concrete, the existing reinforcement methods for printed concrete as well as conventional cast concrete from the literature are reviewed and summarized. Through the preliminary evaluation of the suitability and effectiveness of various reinforcement methods, guidelines are proposed to better understand possible solutions to reinforce printed concrete and inspire new practical ideas to fill the current technology void. The conclusions also include the possible improvements of the existing reinforcement methods to be considered in future applications. [ABSTRACT FROM AUTHOR]

A new type of wall system for use in light-frame construction has recently been developed at Penn State University to allow for maximum daylighting and the use of glazing integrated photovoltaics to generate electricity. One structural option of the proposed wall system employs structural steel tubing to form the gravity load-bearing frame and polycarbonate sheets to perform the sheathing function. The exterior skin of the wall consists of a glazing system, which includes aluminum framing and glass panes that incorporate photovoltaics. Preliminary structural tests are presented to show the gravity load carrying capacity of the steel framing and in-plane lateral load carrying capacity of the polycarbonate sheathing. Similar tests were also carried out on conventional wood-frame panels to serve as benchmarks for evaluation of the proposed system. This paper mainly focuses on the structural system and provides a summary of the structural test results, which show that the proposed system can provide gravity and lateral load resistance. The results of this investigation also identify the need for follow-up studies to optimize the proposed design for cost effectiveness and increased thermal insulation. [ABSTRACT FROM AUTHOR]

This paper presents a finite-element modeling option to provide an analytical approach for a seismic analysis of dry-glazed curtain-wall systems. In this modeling approach, Ansys finite-element software was used to model the glass panel, aluminum glazing frame, perimeter rubber gaskets, rubber setting and side blocks, glass-to-frame clearances, and glass-to-frame contact once the clearance was overcome by in-plane drift. The results of the finite-element modeling of the curtain-wall system were compared with full-scale laboratory test results. The effect of some of the parameters such as gasket friction and aspect ratio were evaluated. The study showed that finite-element modeling is a viable approach for analytical evaluation of curtain walls. The modeling can function to predict the drift associated with glass-panel cracking. Further refinement of the modeling approach developed can increase the accuracy of the prediction. [ABSTRACT FROM AUTHOR]

This paper introduces a panelized brick veneer over steel stud backup wall system to address some of the shortcomings of conventional systems. Thermal and hygrothermal analyses of the proposed wall system with different stud gauges and arrangements are discussed. The movement joint design aspects, a pressure moderation performance evaluation, the simulated wind-driven water penetration results, and an example cost analysis are also presented. This study provides information about some of the attributes of the proposed system such as crack resistance and water penetration potential as well as the pressure moderation aspect. Some of the issues that need consideration for the practical application of the system are also described. [ABSTRACT FROM AUTHOR]

This article presents the experimental data obtained from four-point loading of AAC lintels and compares the measured failure loads with capacities predicted using the conventional strength-design method. Fiber-reinforced polymer (FRP) fabrics are used to strengthen existing concrete structures as an alternative to externally bonded steel plates. Design approaches have been developed for application of FRP on conventional concrete surfaces, but there are other types of concrete materials that have not been sufficiently studied for FRP application. Autoclaved aerated concrete (AAC) is one such material introduced in the US market in the mid 1990s. There is an interest in evaluating the feasibility of application of FRP to retrofit existing structures or components made of AAC (e.g., AAC lintels, floor panels, wall panels, etc.). The specimens used in this study include AAC lintels without FRP and with two alternative schemes of FRP applied to the external lintel surfaces for flexural and shear strengthening. Specimens of conventional reinforced concrete were also tested for comparison with AAC when both are strengthened with FRP. The measured test data provide a basis for evaluating the accuracy of existing strength-design equations to predict the capacity of such specimens. Test results show that the application of FRP at the bottom of the lintels, in combination with U-wrap at the ends of the lintels, increases the load and deflection capacities. Comparison of test results and calculated strengths shows that the existing guidelines such as ACI 440.2R and ACI 523.4R give safe estimates of shear and flexural strength for FRP-enhanced AAC lintels. [ABSTRACT FROM AUTHOR]

This paper summarizes the findings of an experimental study to characterize the cyclic racking and monotonic loading performance of wood-stud and steel-stud wall specimens, which were sheathed on both faces with gypsum wall board (GWB). Some specimens were finished with joint compound at the GWB joints and over screw heads. The study provided data on monotonic and cyclic hysteresis load-displacement relationships. Based on the visual inspection of the specimens during the tests, several aspects of the failure modes were noted. Shear-load capacity and drift capacities were determined based on the envelope curves of the hysteresis cycles. A comparison of the envelope curves for steel-stud and wood-stud specimens provided insight as to the relative behaviors of the two wall system types, including capacity, measures of ductility, and energy dissipation. Finally, the study provided better understanding of the effects of finishing GWB joints on the shear capacity of the wall systems. [ABSTRACT FROM AUTHOR]

Presented herein are the details and results of an experimental study conducted to evaluate the performance of a proposed infill wall fuse system. The purpose of this system, referred to as the seismic infill wall isolator subframe (SIWIS) system, is to prevent damage to columns or infill walls due to infill-frame interaction through a “sacrificial” component or a “structural fuse.” The SIWIS system conceptually consists of two vertical and one horizontal sandwiched light-gauge steel studs with SIWIS elements in the vertical members. The experimental study presented here involves the in-plane lateral load testing of a two-bay three-story steel frame in three forms of bare frame, infilled braced frame, and pinned frame equipped with the proposed SIWIS device. In addition, a brick wall in-plane strength test and a series of component tests on three different designs for fuse element were conducted. In the conducted tests, the suggested technique initially engages the infill walls in seismic resistance of the frame, but ultimately isolates them. It is concluded, thus, that the proposed fuse system has the potential for the development of an effective way to reduce earthquake damage in framed buildings with infill walls. [ABSTRACT FROM AUTHOR]

Laboratory experiments subjected full-scale autoclaved aerated concrete (AAC) cladding panel specimens to static monotonic loading and incrementally increased displacement amplitudes of cyclic racking movements. The objective of the study was to characterize the seismic performance of cladding panel walls made up of the newly introduced AAC in the U.S. market. The study found that conventional connectors used to attach AAC cladding panels to structural systems have not been designed for in-plane seismic resistance and would need to be redesigned in order to safely satisfy building code’s allowable drift. [ABSTRACT FROM AUTHOR]

Abstract: The Seismic Infill Wall Isolator Subframe (SIWIS) system is developed for use in building frames with masonry infill walls in order to prevent damage to columns or infill walls and minimize life-safety hazards during potentially damaging earthquakes. The SIWIS system, which consists of two vertical and one horizontal sandwiched light-gauge steel studs with “rigid-brittle” elements in the vertical members, is designed to allow infill wall–frame interaction under wind loading and minor-to-moderate earthquakes for reduced building drift but to disengage them under damaging events. The SIWIS system acts as a “sacrificial” element just like a “fuse” to save the infill wall and frame from failure. Nonlinear finite element models for two cases, a single-bay, single-story steel frame and a two-bay, three-story steel frame, in three forms including bare frame and infilled frame with and without SIWIS system were performed to develop an understanding of how the system responds to lateral loading. Analysis results show that the concept of SIWIS system works in providing initially high stiffness followed by an isolation of infill wall from interaction with the confining frame. Practical design guidelines are proposed and applied to an eight-story office building. [Copyright &y& Elsevier]

Abstract: Results of nonlinear static pushover analyses of five bridges located in Pennsylvania are presented. The bridges, which vary from single column bents to multiple column bents, have reinforced concrete columns with ties at 12 in. spacing. The objective of the part of the study that is presented in the paper is to estimate displacement ductility and force reduction factors for the selected bridges. The procedures used to obtain moment–curvature relations and to perform nonlinear static pushover analysis using linear elastic analysis software are described. Calculated values for displacement ductility factors and response modification factors (-values) are presented. Observations made from the results of a literature review on experimental evidence for ductility of deficient columns are also discussed. [Copyright &y& Elsevier]

This paper is an attempt to determine the effect of vertical ground motion on design of precast concrete cladding panels in seismic regions, particularly in near-source areas. A spandrel-type precast concrete cladding panel is chosen for detailed study and assumed attached to a building in San Francisco. The seismic provisions of International Building Code 2000 and Uniform Building Code 1997 are used to determine the design forces on the cladding panel, which was originally designed as an example in a PCI publication. The provisions of the two codes are compared in light of their requirements related to vertical ground motion consideration and near-source effects. Results of recent research on the relation between vertical and horizontal ground acceleration components as a function of source-to-site distance are also used to illustrate an example of incorporating vertical spectral acceleration effects directly in load combinations. Finally, finite-element modeling and frequency analysis results of the spandrel and floor-to-floor types of cladding panel are discussed. This study shows that the effects of vertical ground motion will cause an increase in the design forces for connections of heavy cladding panels, especially in near-source regions, with the magnitude of the increase dependent on the source-to-site distance. [ABSTRACT FROM AUTHOR]

Results are presented of a pilot study conducted recently at the Pennsylvania State University Building Envelope Research Laboratory (BERL) to investigate the response of curtain wall mock-ups glazed with 6 mm (1/4 in.) annealed monolithic architectural glass panels fitted with anchored applied film under simulated earthquake conditions. Three common film-to-frame anchoring methods were evaluated: (1) structural silicone adhesive [13 mm (1/2 in.) triangular cross section] application along the entire glass panel perimeter; (2) an aluminum bar extrusion to anchor the film to the frame horizontal along only the top of the glass panel; and (3) two aluminum bar extrusions to anchor the film to the frame verticals along the two vertical edges of the glass panel. Serviceability (glass cracking) and ultimate (glass fallout) limit-state data were collected during in-plane dynamic racking tests. Other performance characteristics, such as cohesive failure of the structural silicone adhesive, loss of film-to-glass adhesion, film tearing, damage to aluminum anchor bars, pullout of the filmed glass unit from the frame glazing pockets, and eventual entire unit fallout, were also recorded. These preliminary tests indicated that anchorage type can demonstrably influence both the serviceability (initial glass cracking) and ultimate (glass fragment fallout and entire unit fallout) limit states of “unweathered” filmed glass panels. In this study, the structural silicone anchor provided the best serviceability limit-state performance of the three anchor methods tested, and the top anchor provided the best entire-unit glass fallout resistance. [ABSTRACT FROM AUTHOR]

In-plane dynamic racking crescendo tests were performed on full-scale curtain wall mock-ups dry glazed with six different insulating glass unit (IGU) configurations and one laminated glass unit configuration. The tests were conducted to determine the serviceability and ultimate limit state behaviors of these configurations tested under simulated earthquake-induced lateral drifts. All IGU configurations tested were manufactured with an annealed monolithic pane and a laminated pane with an argon fill and an anodized aluminum spacer between the panes. Several parameters were varied in the laminated pane of each configuration including glass lite thickness and glass type in the laminated pane (annealed, heat strengthened, and fully tempered), and PVB interlayer thickness for the laminated pane. Properties of the annealed inside pane were not varied. For each configuration, average drift values for the occurrence of glass cracking in each IGU pane, glass fallout from the monolithic pane, and pullout and fallout of the entire glass unit are reported. Relevant damage to the aluminum framing is also reported. Results of these tests can be used to assess the seismic resistance of similarly glazed architectural glass panels in practice and to improve the design of asymmetric IGU configurations for use in seismic regions. [ABSTRACT FROM AUTHOR]

One of the concerns with the conventional metal anchors that are used to tie the brick veneer to the backup portion of enclosure walls (e.g. masonry block) is the potential for corrosion. Corrosion reduces the load carrying capacity of such ties and this could lead to brittle failure especially in the event of an earthquake. In this paper, the forces in lateral ties in a typical brick veneer wall system are evaluated when the building is subjected to some earthquake records. Distribution of tie forces resulting from the dynamic analysis of a finite element model of the brick veneer-masonry block wall system are determined and compared to the conventional assumption. The performance of a corrosion resistant stainless steel helical tie is compared with that of conventional masonry ties. The potential advantages of this relatively new type of masonry tie are discussed with respect to its use in seismic regions. [Copyright &y& Elsevier]

The past COVID-19 pandemic has created new demand and expectations for next-generation buildings. Besides proper indoor air quality (IAQ) and daylight in the indoor environment, the building should provide appropriate working conditions. Due to this pandemic, millions have spent longer hours indoors over the past few years. It is imperative to address a multi-objective and multi-function design to control air circulation in the building's shared and isolated spaces while maintaining energy efficiency, humidity control, and other performance standards. This paper analyzed two architectural design concepts that can eliminate energy usage and daylighting inefficiencies and increase the ventilation rate to reduce indoor transmission of airborne particulates and pathogens and unwanted indoor humidity. We have analyzed the impact of courtyards and atria in typical commercial buildings based on architectural principles and practical experience to create a safe and healthy indoor environment for working and living that will improve indoor protection against the past COVID-19 and future similar virus pandemics. The results show that the use of a courtyard or atrium in design builds a positive effect on controlling the indoor environment. • The use of a courtyard or atrium in design builds a positive effect on controlling the indoor environment. • Architectural principles can improve indoor protection against the past COVID-19 and future similar virus pandemic. • A systematic design approach can look at challenges for a building in the post-COVID-19 era that need to be overcome. [ABSTRACT FROM AUTHOR]

With advancement in sensor, control, and communication technologies, homes can now be equipped with more intelligent lighting, HVAC, entertainment, and safety/security systems, as well as appliances with many advanced features, including high energy efficiency. In particular, with computers becoming an integrated part of homes and smart phones offering remote communication with home systems, we are entering a new era in the home industry, an era of smart homes. This paper presents a categorization of smart homes based on their area of focus, such as energy, information and communication, security, health, environmental, home entertainment, and domestic appliances. However, the main objective of this paper is to review different types of energy smart homes in more detail under three major groups, including homes with energy-monitoring systems, systems with control capabilities, and systems with advanced data-processing capabilities. Smart homes with energy-monitoring systems merely provide the total or granular energy-consumption data of the house by using equipment such as in-home displays, whereas systems with control capabilities also include a control unit that can send proper signals for either passive or active measures, such as appliance on/off commands. In contrast, systems with advanced data-processing capabilities include an advanced central processing unit that can provide more complicated analysis results, such as systems that are equipped with an optimization algorithm to optimize the temperature or appliance schedules based on the residents' comfort level and energy cost. Communication networks in smart homes and associated challenges for their design are also discussed in this paper. [ABSTRACT FROM AUTHOR]

Modular methods are sometimes used to enhance productivity in residential construction projects. Modular methods, however, are not appropriate for all projects, and the feasibility of success must be studied on a case-by-case basis. In this article, factors that can affect the feasibility of a modular vertical expansion are explored, and the benefits of using a coarse finite-element modeling approach to help identify those factors are discussed. A case study is used to demonstrate this approach and provide project-specific factors, some of which can be generalized to other modular applications. The results of the case study show the important planning information that can be obtained by studying generalized structure behavior in the front-end portion of the design. Findings suggest that matching the construction method to the proper application and diligent front-end planning have a positive effect on the feasibility of multistory modular projects, especially those that have complex issues to contend with, such as vertical expansion. [ABSTRACT FROM AUTHOR]

The objective of the study presented in this paper was to determine the racking performance of a four-side structural glazing tape curtain wall system. An EN-WALL 7250 (EN-Wall, Las Vegas, NV) unitized curtain wall system was tested using 3M VHB Structural Glazing Tape G23F (3M, St. Paul, MN). Specimens were planar and single story in configuration, features that align with most commercial unitized systems. Racking tests followed a published stepwise protocol to characterize the performance of the system for both unrestrained and restrained end-boundary conditions. Air leakage tests were also performed during to evaluate the wall system serviceability performance with respect to air leakage. Results of these tests on two full-scale specimens are presented herein. In summary, the full-scale specimens did not sustain any damage to the 3M VHB Structural Glazing Tape G23F or the glazing system. Some framing derailment occurred under very high drifts when certain boundary conditions were imposed. A complete description of the unitized system design is presented along with observations of potential serviceability issues. [ABSTRACT FROM AUTHOR]

Although the study of roofing systems (from coverings to structure of the roof) is of great significance to energy efficiency and sustainable development, design and construction of new roofs on top of existing roofs in buildings has not received sufficient attention. This study discusses re-roofing as one of the key options to reduce energy consumption and improve overall building performance. The more conventional choice and more frequently chosen option for building energy retrofit is vertical building envelope components, however, this paper presents the case study of a proposed retrofitting concept for the roof of an existing building. Using a simulation methodology, the research demonstrates how the proposed retrofitting concept improves the energy performance using electricity generated and external conduction gain as evaluation metrics. The proposed novel re-roofing concept consists of thermal insulation, waterproofing and electric energy generation properties. More specifically, the design concept includes a three-layer roofing system consisting of (from exterior toward interior): a PV panel, an EPDM membrane and an insulation layer. The main goal of this study is to develop a concept for an innovative re-roofing solution that demonstrates the feasibility of turning an old building into a watertight and energy producing system. • The study of roof systems is of great significance to energy efficiency. • BIM can be used to study cost-effectiveness analysis for roof systems. • PV panel and insulation retrofits can provide greater energy efficiency improvements. [ABSTRACT FROM AUTHOR]

This study focuses on developing Machine Learning models based on CFD simulations to estimate hurricane induced vertical wave and surge forces on elevated coastal buildings caused by regular waves. In particular, this study aims at addressing the existing gap in designing elevated coastal buildings, which stems from lack of a generalizable equation for estimating vertical hurricane wave and surge forces for a variety of building geometries and wave conditions. To this end, based on a validated Computational Fluid Dynamics (CFD) model, six key variables that affect the wave forces on buildings are considered, which include building dimensions (length and width of rectangular plan buildings) and wave characteristics. In addition, the effect of building length in relation to wave length on the resulting vertical forces is explicitly considered, while the effect of building width is considered implicitly. Subsequently, a Latin Hypercube Sampling (LHS) strategy is implemented for generating 256 random samples, each representing a unique building geometry with a rectangular plan and wave condition scenario. A pipeline is then developed for generating CFD models corresponding to each sample, which are then deployed on a high-performance computing (HPC) cluster, creating a dataset of vertical surge and wave forces. Based on the key design variables, an ensemble of Machine Learning (ML) models is developed to predict vertical wave forces. For the purpose of design and risk assessment, different force levels may be of interest. Therefore, different models were trained to predict multiple levels of forces on elevated buildings, including maximum, average, 25th, 75th, and 99th percentiles of peak forces. The developed model for each of these force levels is then investigated to identify the main building geometry and wave conditions features that affect the resulting forces, which can inform the decisions of the designers in the early-stage phases. For further assistance in the early-stage design, based on a subset of identified important features, a simple expression for each force level is provided to narrow down the design space to top performing early design candidates, while the main estimators can be used for the final design of elevated buildings. Results show that based on CFD simulations, highly accurate and generalizable predictive models with error rates of about 4% on the test set can be developed. • Estimating the vertical surge and wave forces on elevated coastal buildings under regular waves. • Conducting 256 CFD simulations derived from an enhanced Design of Experiment method. • Capturing the effect of building geometry and wave properties on the resulting forces. • Using Ensemble Learning method to provide a highly accurate and generalizable estimate of surge and wave forces. • Identifying new important features that influence the resulting surge and wave forces specific to elevated coastal buildings. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to the dry-glazed curtain walls. Various issues discussed includes the need of seismic demand of interstory drift, glazing systems and use of code equation by curtain wall designers. It further mentions that the cracks present in glasses are caused due to flaw distribution at the edges of glass panel.

A simple method is presented for determining the peak horizontal acceleration of nonstructural components attached to the floor system of multistory structures subjected to strong ground motions. The procedure was developed for nonstructural components based on shake-table data measured on the floor diaphragms of 30 small-scale reinforced concrete test structures. The observed response led to a general expression that directly accounts for the level of inelastic response of the structures. Floor acceleration data from existing instrumented buildings during strong seismic events were used to test the validity of the method. The method was also assessed analytically using acceleration data calculated after nonlinear dynamic analyses of 6- and 12-story reinforced concrete frames subjected to a suite of 10 ground motions scaled to three intensity levels to cause varied degrees of inelastic response in the frame elements. These analyses allowed the inclusion of flexible nonstructural components in the assessment. The formulation involved may be easily incorporated into the framework of modern seismic design provisions for nonstructural components. It is shown that the proposed method outperforms the one in modern model building codes. [ABSTRACT FROM AUTHOR]

SUMMARY Seismic isolation is an effective method for protecting the structural system, nonstructural systems and content from the damaging effects of strong horizontal earthquake ground shaking. However, seismic isolation devices widely used in the USA and elsewhere are not designed to protect nonstructural components and content from strong vertical earthquake ground shaking. Past research efforts aimed at developing three-dimensional isolation have resulted in systems that have limited application or are overly complex, cost prohibitive and unproven. A distributed flexibility and damping concept to control vertical acceleration demands in base-isolated buildings is explored in this study. Unlike past efforts to achieve three-dimensional isolation that concentrate both the horizontal and vertical flexibility at the base of the superstructure, the vertically distributed flexibility and damping concept explored here consists of one or more planes of laterally restrained column bearings distributed at discrete locations up the height of a base-isolated superstructure. The laterally restrained column bearings increase the vertical flexibility and damping in the superstructure without increasing rocking displacements. An analytical study was performed to understand the influence of incorporating vertical flexibility and damping in a base-isolated frame and to evaluate the effectiveness of the concept for controlling vertical acceleration demands. The distributed flexibility and damping concept is shown to significantly reduce vertical acceleration demands and the likelihood of damage to suspended ceiling systems by comparison with an identical conventionally base-isolated frame. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]