Accelerated Carbonation of Calcium Aluminate Cement (Cac)-Based Cementitious Materials Using Additive Manufacturing

Abstract

Binder jet additive manufacturing produces three-dimensional shapes by jetting a binder or activator onto a powder bed. Calcium aluminate cement (CAC) powder was introduced to the powder bed as a binder, and 97% deionized water was used as an activator to successfully manufacture a CAC-based cementitious green body (CT-G). The addition of a small amount of nanosized silica fume improved the flowability of the powder and the wettability of the aggregate-cement mixture, enabling precise control of the rheological properties of the powder for binder jet additive manufacturing. CT-G underwent carbonation in a pressure reactor at 99.9% CO2, 4 bar pressure, and > 60% relative humidity, and at ambient temperature for 2, 12, 24, 48, and 72 h (CT-xC). The CT-24C sample showed significantly improved mechanical properties after a short period of carbonation of 24 h, and successfully immobilizing 12 wt% CO2 within the CAC-based material matrix. Therefore, the 3D-printed CAC-based cementitious material demonstrates the capability to immobilize CO2.

Keywords: Additive manufacturing, Calcium aluminate cement(CAC), carbonation, cement, binder jet