Next Generation Concrete: Exploring the CO2 Sequestration Potential of Low-lime Binders Enabled by Materials Architecture and Additive Manufacturing, Nadia Ralston, UG '22 (3967491)

As society pushes towards industrialization and growing needs for development occur, the global demand for Ordinary Portland cement (OPC) is expected to rise concurrently. Yet, as one of the largest sources of anthropogenic greenhouse gas emissions, there is also an increasing need to shift towards sustainable cement technology. While hydraulic cement, such as OPC, hardens via hydration, non-hydraulic cement hardens through a process called carbonation in which the material sequesters $CO_2$. With a significantly reduced carbon footprint, this makes non-hydraulic cements such as calcium silicate (CSC) a promising alternative to OPC. When coupled with additive manufacturing, a rapidly developing field in sustainable concrete construction, CSC can enhance the mechanical properties and durability of the cement. This thesis focused on a specific binder of CSC called wollastonite where a set of 3D-printed linear and cellular filaments were tested and the carbonation degree and mechanical properties were examined. It was found that 3D printing the material provides a comparable carbonation degree to cast counterparts. As research continues to develop on the properties of low-lime cement, my findings show that additive manufacturing can enhance the in-depth sequestration and carbonation degree which will lead to improved mechanical properties and wider adoption of low-lime binders.