Title:
Enhanced Carbon-Intake of MgO Paste Structures via 3D Printing
Author(s):
Ala Eddin Douba
Publication:
Web Session
Volume:
ws_S23_AlaEddinDouba.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
4/2/2023
Abstract:
3D-printed concrete is vulnerable to excessive evaporation during its fresh state due to the lack of protective formwork. This is problematic for a system like Portland cement (PC), which requires water to sustain hydration and strength development. However, it can introduce benefits to a system like reactive magnesia (MgO), which undergoes a hydration reaction similar to PC to gain binding properties, but its mechanical strength is developed through carbonation, where the system “soaks up” gaseous CO2 to form solid carbonates. Evaporation of water can help increase CO2 diffusion. Further, 3D printing opens up the possibility of increasing the exposed surface area for CO2 diffusion and minimizing the required penetration depth. In this work, we tailor the rheology of MgO pastes with a combination of nano clays and methylcellulose to make them suitable for 3D printing. Results show that irrespective of the print infill, 3D-printed MgO paste specimens exhibited significantly higher compressive strength (up to 430%) than the conventionally cast one after 28 days of accelerated CO2 curing.