Journal: RILEM State-of-the-Art Reports

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Springer

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ISSN

2213-2031
2213-204X

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2016 - 201912020 - 20225
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Publications 1 - 6 of 6
  • Structural Design and Testing of Digitally Manufactured Concrete Structures
    Item type: Book Chapter
    Asprone, Domenico; Menna, Costantino; Bos, Freek; et al. (2022)
    RILEM State-of-the-Art Reports ~ Digital Fabrication with Cement-Based Materials
    The form freedom enabled by digital fabrication with concrete technologies provides advantages for a wide range of concrete based objects, from architectural to structural elements. The current chapter focuses on the specifics of structural design and engineering of DFC with emphasis on those technologies based on Additive Manufacturing with extrusion. Since it is a new and innovative way to build, a clear common approach to structural engineering has not yet been developed. As a result, this chapter aims to introduce the specific challenges of structural design and engineering with the additive manufacturing technology, providing an overview of structural typologies that have been developed (especially concerning the reinforcement strategies, including fibre reinforcement). Furthermore, the structural principles adopted in DFC and the codified approaches used in conventional reinforced concrete is compared, and putative structural testing procedures and validation methods for DFC are reported.
  • Digital Fabrication with Cement-Based Materials: Underlying Physics
    Item type: Book Chapter
    Mechtcherine, Viktor; Fataei, Shirin; Bos, Freek P.; et al. (2022)
    RILEM State-of-the-Art Reports ~ Digital Fabrication with Cement-Based Materials
    The comprehending of the processes’ physics is a prerequisite for the purposeful design and optimization of digital fabrication systems, as well as their efficient and robust process control. This chapter presents an overview of the underlying physics relevant to an understanding of the processing of cement-based materials during various production steps of digital fabrication. In this, the main focus was on various approaches of Additive Manufacturing, but selected aspects of formative processes were addressed as well. For some processes, analytical formulas based on the relevant physics have already enabled reasonable predictions with respect to material flow behaviour, buildability, and other relevant features. Nevertheless, further research efforts are required to develop reliable tools for the quantitative analysis of the entire process chains. To accomplish this, experimental efforts for the characterization of material properties need to be accompanied by comprehensive numerical simulation. The presented work results from collaborative research carried out by the authors in the framework of the RILEM Technical Committee 276 “Digital fabrication with cement-based materials”.
  • Digital Fabrication with Cement-Based Materials: Process Classification and Case Studies
    Item type: Book Chapter
    Buswell, Richard A.; Bos, Freek P.; Silva, Wilson Ricardo Leal da; et al. (2022)
    RILEM State-of-the-Art Reports ~ Digital Fabrication with Cement-Based Materials
    The need for methods for forming concrete has existed for as long as concrete has been used in constructing the built environment. Creating flat, rectilinear formers have traditionally been the cost and time efficient default for the majority of applications. The desire for greater design freedom and the drive to automate construction manufacturing is providing a platform for the continued development of a family of processes called Digital Fabrication with Concrete (DFC) technologies. DFC technologies are many and varied. Much of the material science theory is common, but the process steps vary significantly between methods, creating challenges as we look towards performance comparison and standardisation. Presented here is a framework to help identify and describe process differences and a showcase of DFC application case studies that explain the processes behind a sub-set of the technologies available.
  • Environmental Potential of Earth-Based Building Materials: Key Facts and Issues from a Life Cycle Assessment Perspective
    Item type: Book Chapter
    Ventura, Anne; Ouellet-Plamondon, Claudiane; Röck, Martin; et al. (2022)
    RILEM State-of-the-Art Reports ~ Testing and Characterisation of Earth-based Building Materials and Elements.
    The global challenge of large-scale climate change mitigation requires action also in the building and construction sector. From a life cycle perspective, and considering the mitigation timeframe, the issue of reducing embodied GHG emissions is gaining attention. Effective ways to reduce embodied GHG emissions have been proposed by the use of fast-growing, bio-based materials, due to carbon sequestered in the biomass. Another promising, yet largely under-explored option is to harness the environmental potentials and low embodied GHG emissions of earth-based materials for building construction. Earth construction dates back from 10,000 to 8000 BC and has been derived in many vernacular construction techniques. More recently, some earthen techniques have been modified, using stabilizers, mainly cement and lime, to increase strength and water stability. The objective of this article is to compare existing literature performed on the LCAs applied to various earthen construction techniques and seek for key factors. Transports as well as binder stabilizations are very influent on the results. Climate, nature of local soil, and geographical context are very influent on functionalities of buildings, mix design and transports, themselves influencing environmental impacts. According to design choices and local context, earthen construction is not always better than concrete. This means that no universal solution can be recommended with the LCA of an earthen wall. The solution has to be adapted to the local context. All references comparing walls material to conventional materials at the building scale, find better environmental performances of earthen walls compared to fired brick walls. However, a full comparison between earthen construction and conventional materials should account for the use phase: combining LCA models with thermal and durability models is a key research issue. Finally, it certainly would be useful to seek for solutions with best environmental performances in a local context, accounting for the nature of soil, the building’s functional requirements as well as geographical and cultural specificities. Such an approach would ensure to lower environmental impacts but represents a drastic change in current construction practices. Whereas today building materials are standardized in order to fit with construction working practices, this paradigm shift would require to adapt construction working practices to the local material and context. As earthen construction is today, in many countries of the world, a re-emerging technique, and new professional practices are yet to be established, it seems possible to make this paradigm shift happen. Certainly, in the current context of the need to substantially reduce building-related GHG emissions, there is still strong potential in earth construction techniques for both research and building practice.
  • Statistical procedures for performance-based specification and testing
    Item type: Book Chapter
    Stahel, W.A.; Moro, F.; Luco, Luis F. (2016)
    RILEM State-of-the-Art Reports ~ Performance-Based Specifications and Control of Concrete Durability
  • Printable Cement-Based Materials: Fresh Properties Measurements and Control
    Item type: Book Chapter
    Wangler, Timothy; Flatt, Robert J.; Roussel, Nicolas; et al. (2022)
    RILEM State-of-the-Art Reports ~ Digital Fabrication with Cement-Based Materials
    Digital fabrication with cementitious materials is a rapidly growing field of research in which the evolution of strength during the various processes, such as 3D printing, is the key controlling parameter. The strength evolves over multiple orders of magnitude during the process, and thus, it is essential to properly characterize the strength evolution in order to guarantee process success. This chapter summarizes the state of the art in these characterization methods for digital fabrication with fresh cementitious materials, reviewing well-known and more recently developed methods.
Publications 1 - 6 of 6