Bautechnik最新文献

Report of the working group for recommendations on excavations: Eurocode 0, Eurocode 7, design of struts, drained or undrained analysis

The working group for excavations of the German Geotechnical Society (DGGT) has since 1968 regularly published recommendations for analysis, design and construction of excavations. The present report provides an overview of current works of the working group. In the reporting period, the focus is on the participation in commenting on the drafts of the new Eurocode 7, the design of struts and the design assuming drained or undrained conditions.

Assessment methods for dismantled reinforced concrete elements in view of their reuse

The aim of the newly established Collaborative Research Center CRC 1683 “Interaction Methods for the Modular Reuse of Existing Structures” is to research the genuine reuse of concrete structures at a structural level and to develop fundamental scientific methods for this purpose. The idea is to deconstruct the existing structures into elements in a planned manner instead of demolishing them. To this end, the extracted elements must be characterized in terms of their properties, refurbished or strengthened if necessary, and assembled into new load-bearing structures in a modular fashion. Over the planned duration of the CRC the entire process chain will be systematically and collaboratively covered within sub-projects, project groups and interaction chains. The interaction chain “Governing Uncertainties” presented herein focuses on the development and testing of experimental, numerical and data-driven methods and strategies for a comprehensive yet fast and non-destructive characterization of the dismantled elements. On this basis, durability and load-bearing models are to be developed to enable the reliable prediction of the remaining service life under various load scenarios and exposures during reuse taking into account the multiple uncertainties. This paper presents the aims, interactions and methods of the sub-projects involved in the interaction chain.

Design for Manufacturing and Assembly as a design principle for modular precast concrete construction: Application examples from the DFG Priority Programme 2187

While the German construction industry has been struggling with stagnating productivity growth for several decades, other manufacturing industries have been able to significantly increase their productivity through digitalisation, automation and rationalisation of manufacturing processes. The Design for Manufacturing and Assembly (DfMA) principle, which considers the planning of manufacturing and assembly as an integral part of the design process and systematically quantifies and evaluates their impact on time and cost at an early stage, has been a major contributor to this productivity growth. The construction industry can also benefit from the principles of DfMA and apply them, for example, in the design of industrially prefabricated structures made of modular precast concrete elements. In the Priority Programme 2187 “Adaptive modularised constructions made in a flux” by the German Research Foundation, such modular construction methods are being investigated in a holistic and interdisciplinary approach, from design and production processes to automated quality control and digital representation. This article shows how DfMA is applied as a design principle in this context and which design solutions have been derived from it in the individual subprojects of SPP 2187.

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Auch bei Treppen kann der Bauablauf mit effizienten Lösungen und Bauteilen deutlich beschleunigt werden. Im Bild: Ein mit dem Trittschalldämmelement Schöck Tronsole vorgefertigtes Treppenpodest wird in Rekordzeit in das bestehende Gebäude eingehoben und schallisoliert fixiert. (Foto: Schöck Bauteile GmbH) Siehe Bericht S. A4 f.

Modular reuse of existing load-bearing structures

Natural processes run in cycles. On decay follows full regeneration. Such circularity is not yet rooted in the principles of structural engineering. At the end of service, buildings are demolished and, when feasible, disassembled for recycling. This also applies to reinforced concrete construction with its vast building stock. Demolition triggers a fatal downcycling process in which the concrete is used as bulk material or disposed of in a landfill. However, near the end of service, capacity deficits are seldom the key factor; utilization limits or construction regulations are decisive instead. The consequences are an enormous waste of resources, such as sand or gravel, greenhouse gas emissions from reprocessing and waste. Reuse means the repeated use of reinforced concrete as structural components (modules). No longer needed buildings are deconstructed into load-bearing elements, characterized, refurbished, and assembled into new modular structures, creating a circular modular system. The Collaborative Research Center 1683 at Ruhr University Bochum is a multidisciplinary cooperation addressing modular reuse. It develops design and repair concepts for load-bearing structures made of reused reinforced concrete, automated characterization and processing, and processes for logistics, deconstruction, and sustainability assessment. This paper presents early concepts and demonstrators of such envisaged structures.