Innovative concrete carbon mixing system: Preliminary results

The concrete industry faces increasing pressure to reduce its significant greenhouse gas emissions. One promising strategy involves sequestering carbon dioxide by mineralizing it with earth metal oxides in cementitious materials. This work presents preliminary results from a field test conducted at a pilot batching plant equipped with an innovative CO2 injection system. A reference concrete mix was produced with different CO2 injection protocols to evaluate process efficiency in terms of mechanical performance and carbonation. Thermogravimetric analysis confirmed effective CO2 sequestration, with an increase in the calcite peak compared to the reference. However, mechanical performance was partially impaired by the injection process, despite continued hydration in both the injected and reference mixes over time. Additionally, slight pore structure refinement was observed in the injected concrete. The carbon sequestration levels achieved were comparable to state-of-the-art laboratory values, highlighting the potential for field application. Future work will focus on refining the injection process to optimize mechanical performance while maximizing CO2 uptake, ultimately contributing to significant emission offsets in concrete production.