As part of a research project by the “Forschungsgemeinschaft Transportbeton e. V. (FTB)”, a practical trial entitled “ReadyCarbonCret” was carried out with the support of SCHWENK Beton Dresden GmbH & Co. KG. New components made of carbon concrete are currently mainly manufactured in precast concrete plants. With the development of carbon reinforcements with larger cross-sections and bar spacings, as well as increasing experience in handling carbon concrete, applications with in-situ concrete in new construction and existing structures are now increasingly coming into focus. The aim of the “Industrielle Gemeinschaftsforschung (IGF)” project is to demonstrate the practical suitability of carbon concrete for in-situ concrete components based on ready-mix concrete. The development of mixture designs within the project is carried out using cementitious systems with reduced clinker content. A practical trial is intended to confirm the findings obtained and feed them into the standardization work on carbon concrete. The F. A. Finger Institute for Building Materials at the Bauhaus University of Weimar is dedicated to concrete technological issues, and the Institute for Structural Engineering (IMB) at TU Dresden is responsible for the topic of “composite structural behavior”.

To investigate the use in ready-mix concrete plants, practical tests for the production and processing of concrete for carbon concrete components took place on August 13, 2024, at SCHWENK Beton Dresden GmbH & Co. KG at the Hafen plant. Under summery conditions and air temperatures well over 30 °C, the concrete was able to prove its robustness and performance. The CEM III/B 42.5 L-LH/SR(na) from the SCHWENK cement plant Bernburg was used in conjunction with limestone flour and conventional aggregates up to a maximum grain size of 8 mm. With admixtures from Master Builders Solutions, the concrete was adjusted to a consistency of F6. A number of fresh and hardened concrete tests were carried out by the research institutions. In addition, at the end of the test series, the pumpability of the concrete was tested using a concrete pump. Pumping was also possible without any problems. At the end of the day, the research institutions of Weimar and Dresden were satisfied with the results achieved. The project is not yet complete. As things stand, it appears that it is possible to produce concrete for carbon concrete applications in ready-mix concrete plants.

Image: Test slabs with carbon concrete.