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Year: 2024

Evaluating the Impact of CO2 on Calcium SulphoAluminate (CSA) Concrete

Akerele, D. D., & Aguayo, F. (2024). Evaluating the Impact of CO2 on Calcium SulphoAluminate (CSA) Concrete. Buildings, 14(8), 2462. https://doi.org/10.3390/buildings14082462

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Abstract

The construction industry is a significant contributor to global CO2 emissions, primarily due to the extensive use of ordinary portland cement (OPC). In response to the urgent need for sustainable construction materials, calcium sulphoaluminate (CSA) cement has emerged as a promising alternative. CSA cement is renowned for its low carbon footprint, high early-age strength, and superior durability, making it an attractive option for reducing the environmental impact of construction activities. While CSA cement offers benefits in carbon emissions reduction, its susceptibility to carbonation presents challenges. Although the body of literature on CSA cement is rapidly expanding, its adoption rate remains low. This disparity may be attributed to several factors including the level of scientific contribution in terms of research focus and lack of comprehensive standards for various applications. As a result, the present study sets out to track the research trajectory within the CSA cement research landscape through a systematic literature review. The study employed the Prefer Reporting Item for Systematic Review and Meta-Analysis (PRISMA) framework to conduct a literature search on three prominent databases, and a thematic analysis was conducted to identify the knowledge gap for future exploration. The study revealed that while CSA concrete demonstrates superior early-age strength and environmental resistance, its susceptibility to carbonation can compromise structural integrity over time. Key mitigation strategies identified include the incorporation of supplementary cementitious materials (SCMs), use of corrosion inhibitors, and optimization of mix designs. The review also highlights the global distribution of research, with notable contributions from the USA, China, and Europe, emphasizing the collaborative effort in advancing CSA concrete technology. The findings are crucial for enhancing sustainability and durability in the construction sector and advancing CSA binders as a sustainable alternative to traditional cement.

Keywords

concrete; calcium sulphoaluminate cement (CSA); mechanical properties; carbonation (CO2); durability; sustainability

Energy Efficiency Retrofitting of Existing Building Stock for Net Zero

Tetteh, M. O., Darko, A., Boateng, E. B., & Chan, A. P. C. (2024). Energy Efficiency Retrofitting of Existing Building Stock for Net Zero. In Rethinking Pathways to a Sustainable Built Environment (pp. 142–158). Routledge. https://doi.org/10.1201/9781003317890-9

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Abstract

Existing buildings’ retrofits improve energy efficiency and are a crucial part of global decarbonization plan. There is a need for a better understanding of public sentiment toward energy efficiency retrofitting of existing buildings (EEREB) to effectively promote its widespread adoption through policy interventions. Currently, there is a lack of comprehensive studies that assess the general public's sentiments toward EEREB. This chapter utilizes social media data to assess the overall public's sentiments of EEREB. Sentiment analysis was used to analyze a total of 3,306 comments from the social media platform YouTube. The concerns and perceptions of the public were analyzed using a Latent Dirichlet Allocation model, which identified nine main themes. These themes include ventilation, energy efficiency, indoor environment quality, comfort and occupant behavior, cost considerations, community engagement, technology usage, implementation knowledge, and social impact. The public expressed stronger positive sentiments, with about 64% reporting favorable views of EEREB and acknowledging its benefits. In addition, interesting patterns of perceptions shaped by a combination of generic and local-specific factors were identified. This chapter enhances the understanding of the general public's needs, concerns, and views on EEREB. Additionally, it could provide valuable insights for policymakers to refine or develop more effective actions in support of EEREB.

Green Finance: A Tool for Financing Green Building Projects

Debrah, C., Chan, A. P. C., Darko, A., Owusu-Manu, D.-G., & Ohene, E. (2024). Green Finance. In Rethinking Pathways to a Sustainable Built Environment (pp. 277–302). Routledge. https://doi.org/10.1201/9781003317890-18

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Abstract

Green building is an “unheralded hero” in the global emissions fight. Its business case has raised demand from several stakeholders. It is seen as a multitrillion-dollar business opportunity of the next decade, leading to increased green finance (GF) investment for green building. GF is accepted as a tool to finance climate change mitigation and adaptation actions, including buildings and construction. To promote GF for green building, collaboration efforts between governments, businesses, investors, and the public are key. This chapter presents the evolution of GF for green building, an overview of the implementation and its potentials, with a focus on the role of stakeholders, policies, regulations, and incentives. Typologies of GF for green building and some examples of success stories are discussed. Other related issues such as green standards, green certifications, and green indices are examined. This chapter facilitates a systematic and comprehensive understanding of the subject. Overall, it summarises the development of GF in this field and the consequent impact on climate action.

Automated daily report generation from construction videos using ChatGPT and computer vision

Xiao, B., Wang, Y., Zhang, Y., Chen, C., & Darko, A. (2024). Automated daily report generation from construction videos using ChatGPT and computer vision. Automation in Construction, 168, 105874-. https://doi.org/10.1016/j.autcon.2024.105874

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Abstract

Daily reports are important in construction management, informing project teams about status, enabling timely resolutions of delays and budget issues, and serving as official records for disputes and litigation. However, current practices are manual and time-consuming, requiring engineers to physically visit sites for observations. To fill this gap, this paper proposes an automated framework to generate daily construction reports from on-site videos by integrating ChatGPT and computer vision (CV)-based methods. The framework utilizes CV methods to analyze video footage and extract relevant productivity and activity information, which is then fed into ChatGPT using proper prompts to generate daily reports. A web application is developed to implement and validate the framework on a real construction site in Hong Kong, generating daily reports over a month. This research enhances construction management by significantly reducing documentation efforts through generative artificial intelligence, with potential applications in jobsite safety management, quality reporting, and stakeholder communication.

Keywords

Construction daily report generation; Computer vision; ChatGPT; Construction management; Project documentation

Housing Market Segmentation: A Finite Mixture Approach

Bourassa, S. C., Dröes, M. I., & Hoesli, M. (2024). Housing Market Segmentation: A Finite Mixture Approach. De Economist (Netherlands), 172(4), 291–337. https://doi.org/10.1007/s10645-024-09446-2

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Abstract

This paper investigates the usefulness of adding a discrete choice model to the hedonic model via a finite mixture approach. Our approach leads to different hedonic models for different housing market segments based on household information. As such, the proposed method goes beyond measuring the average price of housing attributes. As a case study, we estimate the finite mixture model for the Miami and Louisville metropolitan areas using information on race, ethnicity, and income from the American Housing Survey. We find that the model outperforms the standard hedonic model or a model with linear interaction terms between demographics and housing characteristics. Moreover, market segmentation is based on a complex combination of race, ethnicity, and income. For Louisville, Black households need 2.5 times higher income than White households to advance to a higher market segment and even at high incomes tend to occupy their own segment. For Miami, low-income, non-Hispanic households live in their own segment even if occupying the same dwelling size as households in other segments.

Keywords

Housing market segmentation; Hedonic model; Finite mixture model; R31; O18; D51

Rapid Assessment of Sulfate Resistance in Mortar and Concrete

Mousavinezhad, S., Toledo, W. K., Newtson, C. M., & Aguayo, F. (2024). Rapid Assessment of Sulfate Resistance in Mortar and Concrete. Materials, 17(19), 4678-. https://doi.org/10.3390/ma17194678

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Abstract

Extensive research has been conducted on the sulfate attack of concrete structures; however, the need to adopt the use of more sustainable materials is driving a need for a quicker test method to assess sulfate resistance. This work presents accelerated methods that can reduce the time required for assessing the sulfate resistance of mixtures by 70%. Class F fly ash has historically been used in concrete mixtures to improve sulfate resistance. However, environmental considerations and the evolving energy industry have decreased its availability, requiring the identification of economically viable and environmentally friendly alternatives to fly ash. Another challenge in addressing sulfate attack durability issues in concrete is that the standard sulfate attack test (ASTM C1012) is time-consuming and designed for only standard mortars (not concrete mixtures). To expedite the testing process, accelerated testing methods for both mortar and concrete mixtures were adopted from previous work to further the development of the accelerated tests and to assess the feasibility of testing the sulfate resistance of mortar and concrete mixtures rapidly. This study also established criteria for interpreting sulfate resistance for each of the test methods used in this work. A total of 14 mortar mixtures and four concrete mixtures using two types of Portland cement (Type I and Type I/II) and various supplementary cementitious materials (SCMs) were evaluated in this study. The accelerated testing methods significantly reduced the evaluation time from 12 months to 21 days for mortar mixtures and from 6 months to 56 days for concrete mixtures. The proposed interpretation method for mortar accelerated test results showed acceptable consistency with the ACI 318-19 interpretations for ASTM C1012 results. The interpretation methods proposed for the two concrete sulfate attack tests demonstrated excellent consistency with the ASTM C1012 results from mortar mixtures with the same cementitious materials combinations. Metakaolin was shown to improve sulfate resistance for both mortar and concrete mixtures, while silica fume and natural pozzolan had a limited impact. Using 15% metakaolin in mortar or concrete mixtures with Type I/II cement provided the best sulfate resistance.

Keywords

accelerated test method; concrete; metakaolin; mortar; natural pozzolan; sulfate attack

Advancing Active Transportation Through Mobility Justice and Centering Community

Baquero, B. I., Berney, R., Romano, E. F. T., Hicks, O., Getch, R., Hall, C., Mooney, S. J., Rosenberg, D., Shannon, K. L., Saelens, B. E., & Hoerster, K. D. (2024). Advancing Active Transportation Through Mobility Justice and Centering Community. Health Equity, 8(1), 72–730. https://doi.org/10.1089/heq.2024.0087

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Abstract

Objectives: We established a community–academic–policy partnership to examine mobility challenges and opportunities by centering members of a diverse South Seattle neighborhood.
Methods: Three participatory research methods were used: (a) 30- to 60-min qualitative interviews with community leaders (n = 12) and members (n = 16); (b) a photovoice with youth (n = 10); and (c) mobility audits. We also engaged extensively in community dissemination and advocacy.
Results: Four major themes emerged: experiences with the built environment; conflicting views on promoting active transportation; experiences of danger, violence, and racism while moving in the community; and pride and connections within the community. Mobility audit findings reinforced many community member messages about needed infrastructure changes. Participants consistently expressed the need for neighborhood and city-wide structural improvements to support transportation and mobility, including enhanced public transportation; better lighting, crosswalks, sidewalks, pavement, and curb cuts; and maintenance of a neighborhood mixed-use trail. Participants shared the importance of community connection while walking, rolling, or using public transit and wanted to maintain this experience.
Conclusions: Collectively, findings identified ways to increase nonmotorized transportation and public transit access, safety, and resilience, centering solutions on communities of color. We disseminated and amplified community recommendations to advance mobility justice in South Seattle via a community forum, developing a website, holding meetings with local leaders, and writing through print and electronic media. A key, novel strength of our project was the addition of community organizations, community–academic partners, and government leaders from the project’s inception. Local leaders should engage in mobility justice-focused community engagement to advance equity.

No Stakeholder Is an Island in the Drive to This Transition: Circular Economy in the Built Environment

Adabre, M. A., Chan, A. P. C., Darko, A., Edwards, D. J., Yang, Y., & Issahaque, S. (2024). No Stakeholder Is an Island in the Drive to This Transition: Circular Economy in the Built Environment. Sustainability, 16(15), 6422-. https://doi.org/10.3390/su16156422

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Abstract

Ensuring optimum utilisation of the Earth’s finite resources engenders the circular economy (CE) concept which has attracted the attention of policymakers and practitioners worldwide. As a bifurcated strategy which involves both scientific knowledge, advanced technologies and behavioural changes, the CE transition is sociotechnical in nature. Yet, prolific studies focus on scientific knowledge and technologies alone, while studies on promoting CE practices or built environment stakeholders’ behaviour are limited. Using Stakeholder Theory, a comprehensive literature review on CE drivers was conducted. Through a questionnaire survey of professionals, key drivers identified were deployed to develop a 20-driver model for CE transition in the built environment. The model is relevant to policymakers and practitioners because it highlights essential drivers for optimum resource allocation. Moreover, the findings apprise policymakers of the drivers that pertain to key stakeholders (i.e., professional and higher educational institutions, society and clients, government and firms), thus stating the requirements for driving each stakeholder to achieve this sociotechnical transition.

Keywords

circular economy; sociotechnical transition; sustainability; drivers; stakeholder theory; waste reduction

Big data analytics in the AEC industry: scientometric review and synthesis of research activities

Ohene, E., Nani, G., Antwi-Afari, M. F., Darko, A., Addai, L. A., & Horvey, E. (2024). Big data analytics in the AEC industry: scientometric review and synthesis of research activities. Engineering, Construction, and Architectural Management. https://doi.org/10.1108/ECAM-01-2024-0144

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Abstract

Unlocking the potential of Big Data Analytics (BDA) has proven to be a transformative factor for the Architecture, Engineering and Construction (AEC) industry. This has prompted researchers to focus attention on BDA in the AEC industry (BDA-in-AECI) in recent years, leading to a proliferation of relevant research. However, an in-depth exploration of the literature on BDA-in-AECI remains scarce. As a result, this study seeks to systematically explore the state-of-the-art review on BDA-in-AECI and identify research trends and gaps in knowledge to guide future research.
This state-of-the-art review was conducted using a mixed-method systematic review. Relevant publications were retrieved from Scopus and then subjected to inclusion and exclusion criteria. A quantitative bibliometric analysis was conducted using VOSviewer software and Gephi to reveal the status quo of research in the domain. A further qualitative analysis was performed on carefully screened articles. Based on this mixed-method systematic review, knowledge gaps were identified and future research agendas of BDA-in-AECI were proposed.
The results show that BDA has been adopted to support AEC decision-making, safety and risk assessment, structural health monitoring, damage detection, waste management, project management and facilities management. BDA also plays a major role in achieving construction 4.0 and Industry 4.0. The study further revealed that data mining, cloud computing, predictive analytics, machine learning and artificial intelligence methods, such as deep learning, natural language processing and computer vision, are the key methods used for BDA-in-AECI. Moreover, several data acquisition platforms and technologies were identified, including building information modeling, Internet of Things (IoT), social networking and blockchain. Further studies are needed to examine the synergies between BDA and AI, BDA and Digital twin and BDA and blockchain in the AEC industry.
The study contributes to the BDA-in-AECI body of knowledge by providing a comprehensive scope of understanding and revealing areas for future research directions beneficial to the stakeholders in the AEC industry.

Keywords

Big data; Big data analytics; AEC; Bibliometric analysis; Systematic analysis

Developing a Body of Knowledge for Green Construction Project Management

Developing a Body of Knowledge for Green Construction Project Management. Darko, Amos & Chan, Albert PC (Eds.). October 2024.

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Abstract

Growing global imperatives to address sustainability concerns have boosted the importance and prominence of green construction projects worldwide. However, project managers may lack the specialist knowledge and/or technical skills to overcome the unique challenges to successfully deliver suitably sustainable green projects. This book aims to address this shortfall by unearthing, refining and synergising the hitherto scattered gems of experiential and theoretical knowledge, into a unified Body of Knowledge for green construction project management.

Comprising both conceptual principles as well as practical case studies, this book for the first time assembles, structures and consolidates a comprehensive body of knowledge for green construction project management that addresses the unique aspects of this critical domain. It will fulfil a now critical need: equipping industry practitioners, researchers and students with the core project management knowledge and skills needed to successfully deliver green construction projects. It is a must-read for anyone who seeks to develop core green construction project management knowledge and skills, and those intending to move into green construction project management.