Freund, Paul

Diploma Thesis:
1911

Topic:
Analysis of the production of exposed concrete surfaces by means of concrete 3D printing

Editor:
Paul Freund

University Professor Responsible:
Univ.-Prof. Dr.-Ing. Dipl.-Wirt.-Ing. Jens Otto

Supervisor:
University Supervisor: Dipl.-Ing. Patrick Maiwald

Editing Period:
04.11.2022 until 25.03.2023

Abstract:
In the context of this work, the topic was whether it is possible to implement fair-faced concrete surfaces with the quality characteristics from conventional in-situ concrete construction using concrete 3D printing processes according to the DBV/VDZ bulletin 'Fair-faced concrete'. As a starting point, requirements for fair-faced concrete were defined on the basis of current standards and challenges in the production of fair-faced concrete components were presented. The focus was on deriving conclusions for the implementation of fair-faced concrete surfaces with the extrusion process, as this additive manufacturing process has so far shown the greatest potential for transfer to construction sites. The evaluation criteria for fair-faced concrete such as porosity, colour uniformity and evenness could be transferred well to the extrusion-based printing process and assessed accordingly. Since the formwork is omitted in concrete 3D printing, the criteria formwork skin classes and formwork joints cannot be applied in this procedure. However, construction joints and fine mortar leaks can be treated manually during printing. manually. The characteristic feature of fair-faced concrete, the texture, which is a
smooth, closed and largely uniform concrete surface, cannot be implemented with
cannot be realised with concrete 3D printing. As an alternative to texture, the printed concrete printed concrete surfaces can be produced with the following quality levels quality levels Q0, Q1, Q2 and Q3 depending on the smoothing process that accompanies the printing process. Therefore Therefore, a working group should define new quality characteristics and extend the DBV/VDZ leaflet 'Exposed concrete' by a second quality level. 'Fair-faced concrete' by a second part, analogous to the innovative concrete printing technology. A protection concept should be developed for the printing process.