This paper is an updated, but totally new, version of “A review on phase change materials (PCMs) integrated in building walls”, an article published in 2011 in Renewable and Sustainable Energy ...Reviews. Both numerical and experimental studies on building walls containing PCMs during the last ten years (2011–2020) are reviewed. The paper also summarizes the main PCMs used in this application and the recent progress in the integration techniques of PCMs in building construction elements. Most of the proposed studies (about 66%) are focused on PCM in walls. In addition, more than half of these studies are numerical where several assumptions are made such as the neglected of both the occupant presence in the building and its behaviour. Based on this review, it is concluded that the used PCMs in building walls showed good potential for reducing both indoor air temperature fluctuations and energy consumption. However, further numerical and experimental studies are needed that take other aspects into consideration, such as the real use of buildings with the occupant behaviour, the economic viability and the environmental impact. This review paper will help scientific researchers and engineers to update the integration techniques of PCM in building walls and to define potential future research works.
•An updated review on PCMs integrated into building walls is presented.•Both experimental and numerical studies over the last ten years are reviewed.•Further studies that take into consideration the real use of buildings are needed.•The economic viability and the environmental impact are not studied sufficiently.
This open access book includes detail on various structures, buildings, and building materials from different structural and sustainability perspectives. It describes how the building industry is ...vital for the achievement of the sustainable development goals, namely, economic growth, social progress, and the effective protection of the environment. The aim of this collection is to foster the design and construction of sustainable structures and buildings to reduce the environmental load, connect with the environment, and benefit the health of occupants. Presenting the knowledge, trends, and developments from a group of contributors in the field working with different kinds of structures, structural components, buildings, and building materials, the book is ideal for practitioners working in commercial settings, as well as engineering students and researchers concerned with sustainability issues.
This open access book compiles the research results of the Collaborative Research Center SFB 837, which has been running since 2010 and will end in 2022, with the topic "Interaction Modeling in ...Mechanized Tunneling". The Collaborative Research Center is funded by the German Research Foundation (DFG) and is currently the world's largest research facility in the field of tunneling. The aim of the publication is to make our scientific findings accessible to the international professional community. The individual chapters deal with all subsystems relevant in mechanized tunneling and their interaction. The latest results of digital planning and real-time tunneling support have been included.
Accident causation theories explain the possible causation mechanisms of accidents, and unsafe behavior is a major component of such causes. Considering the limitation that existing studies rarely ...discuss the interactions among unsafe behaviors in accidents, this paper uses a case study in the Chinese building construction industry to explore the behavioral risk chains of accidents based on complex network (CN) theory. First, accident cases are collected from government websites, and the extracted unsafe acts are classified according to a list summarized based on several safety standards and operating procedures. Second, the rules for forming behavioral risk chains are defined, and then, a behavioral risk chain network of accidents (BRCNA) is established. In addition, Pajek is used to construct the network model. Finally, the topological parameters are calculated and analyzed in the BRCNA. The results show that the BRCNA has the properties of a scale-free and small-world network. These findings indicate the robustness of the BRCNA for random attacks and the high transmission and diffusion efficiency of behavioral risk in the BRCNA, which reflects that some unsafe acts must be critically controlled and that their related unsafe acts in a chain must be collaboratively controlled through safety management. This study is of theoretical and practical significance for accident prevention in the construction industry.
•The interactions among unsafe behaviors in accidents are explored by the BRCNA.•The BRCNA has the properties of being a scale-free and small-word network.•The critical classes and key chains of unsafe behaviors are identified.
Among smart construction technologies, 3D laser scanning technology is used in a variety of applications, including progress measurement, quantity management, reverse engineering (RE), health ...monitoring, mechanical electronic plumbing (MEP), and so on, using point clouds data (PCD) in the architecture, engineering, and construction (AEC) field. This technology is one of the important data acquisition technologies in construction status to perform active project management through the complete and accurate three-dimensional and visual judgment of building acts. The surveying work for setting out a building is the first step in constructing a building; the location of the building must match the design plan for a building to be sustainable. This is because, if a location deviation exceeds the permitted range, the building must be demolished and rebuilt. When this happens, sustainable construction management is impossible due to delays in the construction schedule, increased construction costs, waste generation, and so on. The purpose of this study is to investigate a case where the accuracy of setting out a building was measured in the construction stage of a building and the building layout design was modified by RE. Although the foundation construction of the case building was in progress, it was confirmed that the setting out of the building measured using a 3D laser scanner did not match with the building layout plan. Therefore, there was no legal problem even if the layout plan is modified according to the measured results, so the building layout plan was modified through RE. Consequently, it was confirmed that a case building under construction became sustainable through RE, and that sustainable construction management was possible by preventing construction schedule delays, increased construction costs, and waste generation.
Asmara (the first African country to be inscribed on the World Heritage list since 2017) is a city of great architectural interest, with many buildings of Italian Rationalism (with local stylistic ...variations) highlighting the architectural and urban planning periods of Modernism. Asmara, today, preserves this heritage despite decades of wars and political instability, as well as difficult maintenance and restoration work. The aim of the research is to highlight the technological and constructive aspects of these architectures and to safeguard their originality (as described in the UNESCO Dossier). Today, the patents and construction solutions of these architectures are little researched, but they represent the essence of these works and the architectural and experimental season of those times. The research and classification of this heritage, with “deconstruction” approach, represents the methodological solution to preserve the 'material' and 'immaterial' value of these architectures.
Scalability is a problem common to most existing 3D printing processes, where the size of the design is strictly constrained by the chamber volume of the 3D printer. This issue is more pronounced in ...the building and construction industry, where it is impractical to have printers that are larger than actual buildings. One workaround consists in printing smaller pieces, which can then be assembled on-site. This workaround generates however additional design and process complexities, as well as creates potential weaknesses at the assembly interfaces. In this paper, we propose a 3D printing system that employs multiple mobile robots printing concurrently a large, single-piece, structure. We present our system in detail, and report simulation and experimental results. To our knowledge, this is the first physical demonstration of large-scale, concurrent, 3D printing of a concrete structure by multiple mobile robots.
•Use multiple mobile robot printers in multi-agent settings for collaborative printing•System incorporates localisation, collision avoidance and optimal robot placement•Improve scalability and time efficiency, and demonstrate on-site printing capability•Large structure printed with proposed system in a safe, efficient and scalable manner•First multi-robot simultaneous printing on single concrete structure
The utilization of industrial and agricultural by-products for the production of alkali activated concrete (AAC) has the potential to yield significant benefits towards sustainability goals. To be a ...viable material, the construction industry requires a construction material that achieves the requisite strength and the other property requirements as specified in codes and standards while demonstrating improved sustainability criteria. Fly ash and Rice Husk Ash (RHA) are abundantly available waste products, principally located in Asian countries. Currently, a significant proportion of these materials are disposed of in landfills, lagoons and rivers but offer potential to utilize in AAC. Hence, the identification of variables associated with fly ash and fly ah-RHA blended AAC by utilizing fly ash and RHA is vital. This study quantifies the environmental and economic factors by assessing the Greenhouse gas (GHG) emission, environmental impacts and benefits, and cost analysis of utilizing fly ash and RHA in AAC compared to Portland Cement (PC) concrete. Alkaline activator is a key component responsible for the highest GHG emission, cost and environmental impact amounts obtained for fly ash geopolymer and blended alkali-activated concrete compared with PC concrete. Alkali activators contribute to 74% of the total GHG emission, while heat curing contributed only 9% to the total GHG emission. The addition of 10% RHA to alkali-activated concrete showed a slight benefit for the analysis. Utilization of waste fly ash and RHA is responsible for providing significant benefits in terms of fresh and marine water ecotoxicity by avoiding waste disposal at the dumpsites, rivers, and storage lagoons.
•12% & 48% increment in GHG emission and initial cost was observed, respectively, for blended alkali-activated concrete.•Alkali activators contributed 74% to the total GHG emission of blended alkali-activated concrete.•Addition of 10% RHA leads to a reduction of 1 kgCO2-eq/m3 of GHG emission.•Sodium silicate and sodium hydroxide are responsible upto 97% of the total impact for all categories except marine water ecotoxicity.•Utilization of waste fly ash & RHA provides environmental credits in terms of fresh and marine water ecotoxicity.
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