Large-scale Monolithic Printing with Ready-Mixed Concrete: Challenges and Solutions

Research output: Contribution to book/conference proceedings/anthology/reportConference contributionContributedpeer-review

Contributors

Abstract

Currently, most research work in the field of concrete 3D printing is focused on the use of fine-grained mortar. These building materials are only suitable to a limited extent for large-format, monolithic printing of building structures because they do not comply with existing concrete standards, require a higher binder content, and generally have significant disadvantages in terms of economic and ecological assessments compared to standard-conforming ready-mixed concrete. The article reports on the results of a research project in which concrete mixtures with a maximum grain size of 16 mm, largely complying with current regulations, corresponding test methods, and adapted machinery equipment were developed for extrusion-based printing. In addition to selecting a suitable concrete mix design, there are a number of challenges regarding the machinery technology when processing concrete with a maximum grain size of 16 mm. This includes limiting wear on the extruder by selecting a suitable material for the stator, developing a shaping unit for printing variable layer geometries, and geometrically checking the printed filaments cross-sections during the printing process as a basis for controlling the adequate discharge rate. To ensure a continuous and segregation-free material flow throughout the entire print head, which consists of the reservoir, extruder, and shaping unit, the introduction of vibration energy is an option. The available test results are presented, and recommendations are derived based on this. Overall, the results demonstrate that although the automated printing of monolithic structures with standard-compliant ready-mixed concrete presents specific challenges, these can certainly be overcome with careful material selection, machine design, and process engineering.

Details

Original languageEnglish
Title of host publicationDigital Concrete 2024 - Supplementary Proceedings
PublisherSpringer International Publishing
Pages1-10
Publication statusPublished - 6 Sept 2024
Peer-reviewedYes

Conference

Title4th RILEM International Conference on Concrete and Digital Fabrication
SubtitleDigital Concrete 2024
Abbreviated titleDC 2024
Conference number4
Duration4 - 6 September 2024
LocationScience Congress Center Munich
CityMünchen
CountryGermany

External IDs

ORCID /0000-0002-9168-0835/work/167215917
ORCID /0000-0002-3999-5186/work/167216957
ORCID /0009-0007-2559-908X/work/167217093

Keywords