The fast transition of the concrete industry to net-zero carbon dioxide emissions relies on technologies that can be implemented quickly. Therefore, this project focuses on achieving net-zero concrete using Ordinary Portland Cement (OPC) as the primary binder. Our approach maximizes the performance of OPC in concrete through three primary interventions. First, we employ chemical admixtures to enhance the amount of ettringite – a key hydrate phase – in the binder (aluminate boost). Preliminary research indicates that this enhancement increases the binder's performance while reducing the required amount of clinker, thus decreasing CO₂ emissions. Second, we integrate supplementary cementitious materials (SCM) with the boosted OPC. The use of traditional SCM further increases the hydrate phase volume and thereby helps to lower the carbon intensity further. As the third step, carbonated SCMs will replace the traditional SCMs to act as additional CO₂ sink. The dual strategy of maximizing stable ettringite and utilizing carbonated SCM leads to net-zero CO₂ emissions. Ultimately, this results in concrete with excellent strength and durability and a net-zero CO₂ footprint achievable.

Applicants:

• Gädt, TUM
  Jansen, FAU
  Lowke, TUM