The interdisciplinary research project “Carbon Concrete Composite” (C3) was carried out under the German Ministry of Education and Research programme “Zwanzig20 – Partnership for Innovation” within the initiative “Unternehmen der Region”. Its aim was to enable the widespread use of carbon‑reinforced concrete by providing a detailed assessment of the material’s environmental and health impacts. A central part of the project was the quantification of particulate matter released during the production, use and disposal of carbon concrete, and the development of a reproducible test stand for exposing cell cultures to the generated dust.

The study focused on the processes that are most likely to release airborne particles in the respirable size range. After analysing the energy input per unit mass and the relative speed between tool and material, the category “cutting with geometrically indeterminate edges” was identified as the most relevant. This category includes sawing, core drilling and grinding. Accordingly, the experimental work concentrated on sawing in a laboratory configuration that mimics industrial cutting conditions. The test stand incorporated a rotating saw blade, a HEPA‑filtered air supply to avoid contamination, and safety interlocks to prevent accidental contact with the blade. By running the saw for several hours, a stable aerosol of carbon‑concrete dust was produced, characterised by a consistent particle size distribution and concentration.

The carbon concrete specimens were fabricated by the Otto‑Mohr laboratory of the Institute for Mass Construction at TU Dresden. The reinforcement consisted of a textile grid of carbon‑fiber rovings (TUDALIT‑BZT2‑V.FRAAS). In the longitudinal direction the rovings had a linear mass of 3200 tex and were spaced 12.7 mm apart; in the transverse direction they had 800 tex and were spaced 18.0 mm apart. Each rovings bundle was impregnated with a coating (Lefasol VLT‑1) that covered about 15 % of the surface area, ensuring mechanical bonding of the filaments. The concrete blocks measured 700 mm × 400 mm × 12.5 mm and were cut into 350 mm × 400 mm × 12.5 mm specimens. Three layers of reinforcement were incorporated, giving a maximum reinforcement ratio for a 12.5 mm thick element. The mortar used was a ready‑mix type TF10 from Pagel Spezialbeton. During sawing the longitudinal fibers were cut perpendicular to the transverse ones, preserving the latter and achieving an area fraction of 3.4 % for the longitudinal reinforcement.

Particle characterization employed a suite of granulometric techniques: electrical mobility analysis, light‑scattering detectors, laser diffraction, and scanning electron microscopy. The aerosol generator produced a fine dust aerosol that was subsequently introduced into a cell‑culture exposure system (Vitrocell). The exposure chamber was equipped with a HEPA filter to maintain a clean environment and to ensure that only the generated dust reached the cell cultures. The reproducible generation of dust and its controlled delivery to cell cultures allowed for systematic studies of cytotoxicity and other biological effects.

The project ran for 22 months with a budget of approximately 200 000 €. The core work was performed by the Mechanical Process Engineering group at TU Dresden, with close collaboration from the Building Technology department for assessment of work‑safety aspects. A key partnership was with project V1.5 “Recycling of Carbon Concrete”, which provided practical cutting experiments and samples for validation of the laboratory results. The expertise of the industrial partner MüllerBBM was also leveraged for interpreting dust‑measurement data and fibre‑analysis outcomes. Through these collaborations, the C3 project established a robust methodology for quantifying dust emissions from carbon concrete and for evaluating their potential health risks, thereby laying the groundwork for safer industrial practices and broader adoption of this resource‑efficient construction material.