Carbon-negative Ready-mix Concrete Building Components Through Direct Air Capture
Project Innovation + Advantages:
The University of Wisconsin-Madison will produce carbon-negative concrete building components using cementitious materials generated by a carbon mineralization-based direct air capture (DAC) process. The DAC process uses a novel aqueous carbonation cycle to capture CO2 from the air at low cost. Simultaneously, the process upcycles industrial mineral wastes as cementitious materials by enhancing their pozzolanic reactivity (i.e. ability to form minerals that contribute to strength). The cementitious materials, storing the captured atmospheric CO2 as solid carbonate (e.g., CaCO3), fully replace Portland cement via an alkali activation cementation method in both cast-in-place and precast construction. The resulting carbon-negative concrete offers enhanced durability at equivalent strength and similar cost and can be formed into reusable building components or recycled as carbon-negative aggregates at end of life.
HESTIA projects will facilitate the use of carbon storing materials in building construction to achieve net carbon negativity by optimizing material chemistries and matrices, manufacturing, and whole-building designs in a cost-effective manner.