Pierobon, Francesca; Huang, Monica; Simonen, Kathrina; Ganguly, Indroneil. (2019). Environmental Benefits of Using Hybrid CLT Structure in Midrise Non-Residential Construction: An LCA Based Comparative Case Study in the U.S. Pacific Northwest. Journal Of Building Engineering, 26.
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Abstract
In this study, the cradle-to-gate environmental impact of a hybrid, mid-rise, cross-laminated timber (CLT) commercial building is evaluated and compared to that of a reinforced concrete building with similar functional characteristics. This study evaluates the embodied emissions and energy associated with building materials, manufacturing, and construction. Two alternative designs are considered for fire protection in the hybrid CLT building: 1) a 'fireproofing design', where gypsum wallboard is applied to the structural wood; and 2) a 'charring design', where two extra layers of CLT are added to the panel. The life cycle environmental impacts are assessed using TRACI 2.1 and the total primary energy is evaluated using the Cumulative Energy Demand impact method. Results show that an average of 26.5% reduction in the global warming potential is achieved in the hybrid CLT building compared to the concrete building, excluding biogenic carbon emissions. Except ozone depletion, where the difference in impact between scenarios is < 1%, replacing fireproofing with charring is beneficial for all impact categories. The embodied energy assessment of the building types reveals that, on average, the total primary energy in the hybrid CLT buildings and concrete building are similar. However, the non-renewable energy (fossil-based) use in the hybrid CLT building is 8% lower compared to that of the concrete building. As compared to the concrete building, additional 1,556 tCO(2)(e) and 2,567 tCO(2e) are stored in the wood components of the building (long-term storage of biogenic carbon) in the scenario with fireproofing and with charring, respectively.
Keywords
Wood; Concrete; Energy; Buildings; Impacts; Cross-laminated Timber; U.s. Pacific Northwest; Life Cycle Assessment; Cumulative Energy Demand; Biogenic Carbon; Carbon Storage
Roca, Pere; Liew, Andrew; Block, Philippe; Lopez, David Lopez; Echenagucia, Tomás Méndez; Van Mele, Tom. (2022). A Three-Dimensional Approach to the Extended Limit Analysis of Reinforced Masonry. Structures, 35, 1062 – 1077.
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Abstract
The Extended Limit Analysis of Reinforced Masonry (ELARM) is a simple and user-friendly method for the design and structural analysis of singly-curved, reinforced tile vaults [1]. It is based on limit analysis but takes into account the reinforcement's contribution to the composite cross-section's bending capacity.& nbsp;A three-dimensional approach to ELARM is presented in this paper. The theoretical framework to understand the implications and limitations of extending ELARM to fully 3D structures is described, together with the strategies to carry out the leap from 2D to 3D. This extension is a lower-bound approach for the design of reinforced masonry, reinforced concrete and concrete-masonry composite shells and the assessment of their strength and stability against external loading.& nbsp;The new, extended method is implemented computationally to speed up the iterative processes, provide quick structural feedback, offer immediate results and allow for user-interactive form-finding and optimisation procedures. Different applications of the developed tool are described through the presentation of examples, including reinforcement optimisation, a form-finding process and a case with a shape beyond funicular geometry.
Keywords
Tile Vault; Masonry; Reinforced Brick; Formwork; Concrete Shells; Limit Analysis; Thrust Network Analysis; Extended Limit Analysis Of Reinforced Masonry; Tile Vaults
Ochsner, Jeffrey Karl. (2016). Meditations on the Empty Chair: The Form of Mourning and Reverie. American Imago, 73(2), 131 – 163.
Keywords
Vietnam-veterans-memorial; Photography; Thoughts
Prakash, Vikramaditya. (2019). Dhāranā: The Agency of Architecture in Decolonization. Future Anterior, 16(2), 87 – 120.
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Chen, Cindy X.; Pierobon, Francesca; Jones, Susan; Maples, Ian; Gong, Yingchun; Ganguly, Indroneil. (2022). Comparative Life Cycle Assessment of Mass Timber and Concrete Residential Buildings: A Case Study in China. Sustainability, 14(1).
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Abstract
As the population continues to grow in China's urban settings, the building sector contributes to increasing levels of greenhouse gas (GHG) emissions. Concrete and steel are the two most common construction materials used in China and account for 60% of the carbon emissions among all building components. Mass timber is recognized as an alternative building material to concrete and steel, characterized by better environmental performance and unique structural features. Nonetheless, research associated with mass timber buildings is still lacking in China. Quantifying the emission mitigation potentials of using mass timber in new buildings can help accelerate associated policy development and provide valuable references for developing more sustainable constructions in China. This study used a life cycle assessment (LCA) approach to compare the environmental impacts of a baseline concrete building and a functionally equivalent timber building that uses cross-laminated timber as the primary material. A cradle-to-gate LCA model was developed based on onsite interviews and surveys collected in China, existing publications, and geography-specific life cycle inventory data. The results show that the timber building achieved a 25% reduction in global warming potential compared to its concrete counterpart. The environmental performance of timber buildings can be further improved through local sourcing, enhanced logistics, and manufacturing optimizations.
Keywords
Mass Timber; Embodied Carbon; Climate Change; Carbon Reduction; Building Footprint; Built Environment; Forest Products; Life Cycle Analysis; Environmental Impacts; Wood Laminates; Geography; Concrete; Flooring; Manufacturing; Global Warming; Concrete Construction; Construction Materials; Emissions Trading; Greenhouse Gases; Residential Areas; Energy Consumption; Life Cycle Assessment; Greenhouse Effect; Life Cycles; Construction Industry; Logistics; Floor Coverings; Urbanization; Timber; Urban Environments; Building Components; Emissions; Residential Buildings; Carbon Footprint; Urban Areas; Environmental Impact; Building Construction; Case Studies; Wood Products; Mitigation; Buildings; Timber (structural); United States--us; China
Ochsner, Jeffrey Karl. (2016). Seattle, the Pacific Basin, and the Sources of Regional Modernism. Fabrications-the Journal Of The Society Of Architectural Historians Australia And New Zealand, 26(3), 312 – 336.
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Abstract
The emergence of mid-twentieth-century architecture that was both modern and regional in Seattle and nearby areas of Washington State presents a singular case study demonstrating an array of influences from Asia and Latin America as well as the Pacific Coast of the United States. This network of influences is evidence of the complexity of a dissemination that gained momentum in the 1930s as the modern movement began to spread globally, as identified by historian William J. R. Curtis. Although awareness of distant sources primarily influenced design vocabularies from the 1930s to the 1950s in the Pacific Northwest, by the early 1960s, as Seattle architects and landscape architects began to travel to Japan, they developed a much deeper understanding from a broader collection of sites, and this, in turn, shaped surprisingly varied local responses from Rich Haag's ideas of non-striving design to Victor Steinbrueck's increasing interest in Pike Place Market. Untangling the array of Pacific Basin influences that helped shape mid-twentieth-century design in Seattle provides one demonstration of the validity of considering the Pacific as an interdependent region. Thus, Seattle offers a foundational case study towards the future project of writing an encompassing account of the interconnected architectural history of the Pacific Basin.
Rodriguez, Barbara X.; Simonen, Kathrina; Huang, Monica; De Wolf, Catherine. (2019). A Taxonomy for Whole Building Life Cycle Assessment (WBLCA). Smart And Sustainable Built Environment, 8(3), 190 – 205.
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Abstract
Purpose The purpose of this paper is to present an analysis of common parameters in existing tools that provide guidance to carry out Whole Building Life Cycle Assessment (WBLCA) and proposes a new taxonomy, a catalogue of parameters, for the definition of the goal and scope (G&S) in WBLCA. Design/methodology/approach A content analysis approach is used to identify, code and analyze parameters in existing WBLCA tools. Finally, a catalogue of parameters is organized into a new taxonomy. Findings In total, 650 distinct parameter names related to the definition of G&S from 16 WBLCAs tools available in North America, Europe and Australia are identified. Building on the analysis of existing taxonomies, a new taxonomy of 54 parameters is proposed in order to describe the G&S of WBLCA. Research limitations/implications The analysis of parameters in WBLCA tools does not include Green Building Rating Systems and is only limited to tools available in English. Practical implications This research is crucial in life cycle assessment (LCA) method harmonization and to serve as a stepping stone to the identification and categorization of parameters that could contribute to WBLCA comparison necessary to meet current global carbon goals. Social implications The proposed taxonomy enables architecture, engineering and construction practitioners to contribute to current WBLCA practice. Originality/value A study of common parameters in existing tools contributes to identifying the type of data that is required to describe buildings and contribute to build a standardized framework for LCA reporting, which would facilitate consistency across future studies and can serve as a checklist for practitioners when conducting the G&S stage of WBLCA.
Keywords
Content Analysis; Taxonomy; Lca; Lca Tools; Tools For Practitioners; Whole Building Life Cycle Assessment
Rajendran, Vidhya; Piacsek, Andy; Méndez Echenagucia, Tomás. (2022). Design Of Broadband Helmholtz Resonator Arrays Using The Radiation Impedance Method. Journal Of The Acoustical Society Of America, 151(1), 457 – 466.
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Abstract
This paper describes the design process of a low-frequency sound absorptive panel composed of differently tuned Helmholtz resonators (HRs), considering size and fabrication constraints relevant for applications in the building sector. The paper focuses on cylindrical and spiral resonators with embedded necks that are thin and can achieve high absorption. the mutual interaction between the resonators was modeled based on the radiation impedance method and it plays a key component in enhancing the absorption performance of the array. The differential evolution search algorithm was used to design the resonators and modify their mutual interaction to derive the absorption performance of multiple HR arrays for comparison. Optimizations to the resonator configuration and the neck resistance were implemented to produce a unit panel that has a broadband absorption performance with emphasis on the low to mid frequencies and is thin and light in weight. Unit panels with dimensions of 20 cm x 20 cm , consisting of 29 cylindrical HRs designed to absorb in the 25–900 Hz frequency range, were constructed and tested in a custom-built impedance tube. The measured absorption performance of these panels is consistent with the theoretical predictions. [ABSTRACT FROM AUTHOR]; Copyright of Journal of the Acoustical Society of America is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Keywords
Helmholtz Resonators; Differential Evolution; Search Algorithms; Radiation; Structural Optimization; Resonators; Bandpass Filters
Ochsner, Jeffrey Karl. (2016). The Emergence of Regional Modernism in Seattle Architecture from the 1930s to the 1950s. Pacific Northwest Quarterly, 108(1), 12 – 28.
Adhikari, Pramodit; Mahmoud, Hussam; Xie, Aiwen; Simonen, Kathrina; Ellingwood, Bruce. (2020). Life-Cycle Cost and Carbon Footprint Analysis for Light-framed Residential Buildings Subjected to Tornado Hazard. Journal Of Building Engineering, 32.
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Abstract
Light-frame wood building construction dominates the single-family residential home market in the United States. Such buildings are susceptible to damage from extreme winds due to hurricanes in coastal areas and tornados in the Midwest. The consequences of extreme winds on the built environment and on social and economic institutions within the community can be severe and are likely to increase in the coming decades as a result of increases in urbanization and economic development and the potential impacts of changing climate in hazard prone areas. Current building practices provide minimum standards for occupant safety and health, including structural integrity, water and sanitation, lighting, ventilation, means of egress and fire protection. However, they generally do not consider building resilience, which includes robustness and an ability to recover following extreme natural hazard events. Nor do they address sustainability, the notion that building design, construction and rehabilitation should not adversely impact the environment. In this paper, we establish a generalized cost and carbon footprint life-cycle analysis methodology for examining the benefits of different building practices for residential light-frame wood construction subjected to tornado hazards. A multiobjective approach is used to reveal tradeoffs between resilient and sustainable practices for typical residential construction. We show that when the life cycle of a typical residence is considered, a balance between resilience, sustainability and cost might be achieved in design and rehabilitation of residential building construction for tornado hazards.
Keywords
Performance; Risk; Fragility; Residential Buildings; Life-cycle Analysis; Resilience; Optimal Decisions; Sustainable Construction; Tornadoes