| 1. |
- Alyami, Mana, et al.
(författare)
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Application of metaheuristic optimization algorithms in predicting the compressive strength of 3D-printed fiber-reinforced concrete
- 2024
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Ingår i: Developments in the Built Environment. - 2666-1659. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, the construction industry has been striving to make production faster and handle more complex architectural designs. Waste reduction, geometric freedom, lower construction costs, and speedy construction make the 3D-printed fiber-reinforced concrete (3DPFRC) alternative for future construction. However, achieving the optimum mixture composition for 3DPFRC remains a daunting task, entailing the consideration of multiple variables and necessitating an extensive trial-and-error experimental process. Therefore, this study investigated the application of different metaheuristic optimization algorithms to predict the compressive strength (CS) of 3DPFRC. A database of 299 data samples with 16 different input features was compiled from the experimental studies in the literature. Six metaheuristic algorithms, such as human felicity algorithm (HFA), differential evolution algorithm (DEA), nuclear reaction optimization (NRO), Harris hawks optimization (HHO), lightning search algorithm (LSA), and tunicate swarm algorithm (TSA) were applied to identify the optimal hyperparameter combination for the random forest (RF) model in predicting the CS of 3DPFRC. Different statistical metrics and 10-fold cross-validation were used to evaluate the accuracy of the models. The TSA-RF model exhibited superior performance compared to other models, achieving correlation (R), mean absolute error (MAE), and root mean square error (RMSE) values of 0.99, 2.10 MPa, and 3.59 MPa, respectively. The LSA-RF model also performed well, with R, MAE, and RMSE values of 0.99, 2.93 MPa, and 6.23 MPa, respectively. SHapley Additive exPlanation (SHAP) interpretability elucidates the intricate relationships between features and their effects on the CS, thereby offering invaluable insights for the performance-based mix proportion design of 3DPFRC.
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| 2. |
- Ameen, Arman, 1976-, et al.
(författare)
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Energy saving, indoor thermal comfort and indoor air quality evaluation of an office environment using corner impinging jet ventilation
- 2023
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Ingår i: Developments in the Built Environment. - : Elsevier. - 2666-1659. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The performance of a corner based impinging jet ventilation system (CIJV) in an office environment was evaluated numerically. The evaluation was done both in terms of the local thermal comfort and the local indoor air quality. Three different inlet configurations were tested for a range of outdoor temperatures that included both winter and summer conditions. In terms of indoor air quality, the results showed that CIJV performed better than a traditional mixing system. The study also revealed that CIJV creates a stronger temperature stratification in summertime compared to wintertime. When evaluating the energy saving potential the results showed a possible reduction of 7% for the ventilation flowrate when the outdoor temperatures were between -15 °C and -5 °C, 8 % when the outdoor temperatures were between 0 °C and 10 °C and 9 % when the outdoor temperatures were between 15 °C and 25 °C.
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| 3. |
- Andersen, Sarah Cecilie, et al.
(författare)
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Environmental impacts of circularity in the built environment: How do system boundaries affect decision support?
- 2024
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Ingår i: Developments in the Built Environment. - 2666-1659. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Life-Cycle Assessments (LCA) have become a common tool of decision support in the built environment regarding environmental impacts. The goal of this study is to investigate the influence of different LCA approaches and system boundaries on decision support regarding circular design strategies. Three different ways of applying attributional LCA (ALCA) and one consequential LCA (CLCA) are assessed using a case study of a wooden beam with either virgin or reclaimed timber. While the conclusions are not readily scalable, the case study's results indicate that using reclaimed material is environmentally beneficial when applying ALCA. However, when applying CLCA the reclaimed material performs worse than the virgin material. This highlights the potential pitfalls of scaling up solutions based on LCA results without considering the broader consequences. While the current ALCA approach is useful for declarations, it may not provide comprehensive decision support for driving a transition in the built environment.
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| 4. |
- Bibri, Simon Elias, et al.
(författare)
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Compact City Planning and Development : Emerging Practices and Strategies for Achieving the Goals of Sustainable Development
- 2020
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Ingår i: Development in the Built Environment. - : Elsevier BV. - 2666-1659. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Compact city planning and development has, over the last 30 years or so, been the hegemonic response to the challenges of sustainable development. Global and local policies promote the compact city model due to the positive outcomes of its design principles and strategics as to achieving sustainable cities in terms of their environmental, economic, and social goals. The aim of this paper is to examine how the compact city model is practiced and justified in urban planning and development with respect to the three dimensions of sustainability, and whether any kind of practical progress has been made in this regard. To illuminate the phenomenon of the compact city, a descriptive case study is adopted as a qualitative research methodology where the empirical basis is mainly formed by urban plans in two Swedish cities: Gothenburg and Helsingborg, in combination with qualitative interview data, secondary data, and scientific literature. This study shows that compactness, density, diversity, mixed land use, sustainable transportation, and green space are the prevalent design principles and strategies of compact city planning and development, with the latter being contextually linked to the concept of green structure, an institutional setup under which the two Swedish cities operate. Moreover, at the core of the compact city model is the clear synergy between the underlying principles and strategies in terms of their cooperation to produce combined effects greater than the sum of their separate effects with respect to the benefits of sustainability as regards its tripartite value. Further, this study demonstrates that the compact city model as practiced by the two cities is justified by its ability to contribute to the environmental, economic, and social goals of sustainable development. However, the economic goals dominate over the environmental and social goals, notwithstanding the claim about the three dimensions of sustainability being equally important at the discursive level. Nevertheless, new planning measures are being implemented to address the relevant environmental and social issues towards balancing the three goals of sustainability and thus strengthening their influence over urban development practices.
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| 5. |
- Bäcklund, Katarina, 1982-, et al.
(författare)
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Implementing digital innovations : Overcoming organizational challenges
- 2024
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Ingår i: Developments in the Built Environment. - : Elsevier BV. - 2666-1659. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- While real estate owners play a significant role in advancing digitalization and sustainability within the sector, there's limited understanding of their innovation processes. This article aims to increase understanding on the innovation processes and dynamic capabilities in real estate owner organizations. The article examines a longitudinal case study within a prominent Swedish real estate owner known for significant investments in smart building technologies. Despite these investments, practical benefits face hurdles, reflecting broader challenges in real estate sector digitalization projects. These obstacles include top-down innovation focus, limited cross-functional and user-centric innovation, innovation process discontinuities, ambiguous innovator roles, hierarchical communication, resource constraints, and uncertainties in technology implementation. The study emphasizes the inclusion of diverse perspectives in innovation processes and suggests further research on organizational and user-centric aspects. It contributes to real estate and facility management literature by proposing potential solutions to innovation processes, offering valuable insights for industry practitioners and researchers alike.
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| 6. |
- Forth, Kasimir, et al.
(författare)
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BIM4EarlyLCA: An interactive visualization approach for early design support based on uncertain LCA results using open BIM
- 2023
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Ingår i: Developments in the Built Environment. - 2666-1659. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- To meet the European climate goals in the building sector, a holistic optimization of embodied greenhouse gas (GHG) emissions using the method of life cycle assessments (LCA) are necessary. The early design stages have high impact on the final performance of the buildings and are characterized by high uncertainty due to the lack of information and not yet taken decisions. Furthermore, most current LCA approaches based on Building Information Models (BIM) require high expertise and experience in both BIM and LCA and do not follow an intuitive visualization approach for other stakeholders and non-experts. This paper presents a novel design-decision-making approach for reducing embodied GHG emissions by interactive, model-based visualizations of uncertain LCA results. The proposed workflow is based on open BIM data formats, such as Industry Foundation Classes (IFC) and BIM Collaboration Format (BCF), and is developed for decision support for non-LCA experts in the early design stages. With the help of a user study, the prototypical implementation is tested by 103 participants with different levels of experience in BIM and LCA based on a case study. We evaluate the proposed approach regarding the support of open BIM data formats, different LCA visualization strategies, and the intuitiveness of different approaches to visualizing uncertain LCA results. The user study results show a broad acceptance and need for open BIM data formats and model-based LCA visualization but less for visualizing uncertainties, which needs further research. In conclusion, this interactive, model-based visualization approach using color coding supports non-LCA experts in the design decision-making process in early design stages.
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| 7. |
- Johansson, Lisen, et al.
(författare)
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A comprehensive review on properties of tailings-based low-carbon concrete: Mechanical, environmental, and toxicological performances
- 2024
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Ingår i: Developments in the Built Environment. - : Elsevier. - 2666-1659. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- With concrete’s key role in construction and infrastructure, the reduction of its carbon footprint is critical for addressing global carbon emissions. One strategy to reduce environmental impact from concrete production is to replace cement clinker or fine aggregates in concrete with industrial wastes. Mine tailings, being a high-volume under-utilized resource, possess properties making it suitable for use as a partial substitute for cement or fine aggregates. This review article provides an overview of the recent findings within the topic of tailings-based concrete (TBC). Many of the identified publications aimed to describe the mechanical performance of TBC, and to optimize the concrete mix with respect to the strength and durability. The recommended cement replacement ranged from 5 to 25% and the recommended fine aggregate replacement ranged from 20 to 60%. In general, the compressive strength was decreased with increasing use of tailings as a replacement of cement. For the use of tailings as replacement for fine aggregates, the correlation was more complex, normally the mechanical performance enhanced at low replacement levels, until it reached an optimum after which it decreased. CO2 savings for replacing fine aggregate with tailings were up to 12% and for the cement replacement up to 30%. When assessing the environmental performance, most of the publications did not account for the loss of its mechanical performance, which could lead to the risk of underestimating the environmental impact. This review not only provides a basis for understanding the mechanical, toxicological, and environmental performances of TBCs, but also links the perspectives together, unveiling the connections between them. Moreover, this review presents an organized overview of the topic of TBC and points out topics for future research.
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| 8. |
- Karlsson, Ida, 1980, et al.
(författare)
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Achieving net-zero carbon emissions in construction supply chains - A multidimensional analysis of residential building systems
- 2021
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Ingår i: Developments in the Built Environment. - : Elsevier BV. - 2666-1659. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The construction sector accounts for approximately 25% of global CO2 emissions. In this paper, we provide a multidimensional assessment of the potential for greenhouse gas emissions abatement in relation to the construction of multi-family residential buildings. Different building designs are compared, whereby the study analyzes the potential reductions in greenhouse gas emissions when combining abatement measures with a perspective of the technologies and practices available now, and those that are likely to become available on a timescale up to Year 2045. Further, the assessment analyzes the potential for emissions reductions when applying abatement measures at different points in the supply chain, from primary material production via material composition to the final building structure. The results indicate that the greenhouse gas emissions can be reduced by up to 40% with currently available technologies and practices, with even greater potential reductions of 80% to Year 2030 and 93% to Year 2045.
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| 9. |
- Ljunggren, Fredrik
(författare)
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Innovative solutions to improved sound insulation of CLT floors
- 2023
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Ingår i: Developments in the Built Environment. - : Elsevier Ltd. - 2666-1659. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Building with cross laminated timber (CLT) has gain increased interest over the last years, but in common to other wood-based building systems, inadequate low-frequency sound insulation is seen as a problem. This paper deals with two methods to improve the sound insulation of CLT panels, normally made from spruce: 1) heavy CLT, introducing compressed, i.e. densified, spruce as well as alternative wood species, and 2) elastic layer based upon shear motion. In addition to a series of laboratory measurements, a full-scale CLT floor made of two 60 mm birch panels with a 12 mm elastic layer in between was tested in a two-room test mock-up. The results from the acoustical measurements showed that the floor has about 7 dB greater airborne and impact sound insulation for one-third octave bands, 50–3150 Hz, compared to a standard CLT floor of the same total height.
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| 10. |
- Najeh, Taoufik, et al.
(författare)
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Forecasting maximum formwork pressure for self-compacting concrete using ARX-Laguerre machine learning model
- 2024
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Ingår i: Developments in the Built Environment. - : Elsevier. - 2666-1659. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Forecasting the maximum pressure exerted by cast-in-place self-compacting concrete (SCC) is a major concern for formwork designers, researchers, and site engineers to accurately design the bearing capacity of the formwork and control the casting rate for safe and fast construction. This article aims to utilize the ARX-Laguerre model, which is a data-driven model to forecast the maximum form pressure. A laboratory instrumented setup was used to cast a 2-m column using SCC made with two different types of cement. A pressure system consisting of four sensors was used to document the pressure during casting. The data were sent to the cloud at every 1-min interval for real-time monitoring. The data were used to develop the model. The results demonstrated that forecasting with the ARX-Laguerre model is highly accurate. The model can forecast the maximum pressure exerted by SCC with less complexity. The model performance was also found to be consistent with insignificant differences between actual experimental results and predicted results. With a recursive and straightforward representation, the resulting model, known as the ARX-Laguerre model, ensures the parameter number reduction. Providing fast prediction of the maximum pressure. The model enables formwork designers to forecast the form pressure to design safe formwork and also helps to control the casting rate when SCC is used.
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