Title: Feasibility of Using Natural Pozzolan-Limestone-Based Cement Composite for 3D Printing

Author(s): Haodao Li, Alfred Addai-Nimoh, and Kamal H. Khayat

Publication: Symposium Paper

Volume: 362

Issue:

Appears on pages(s): 344-357

Keywords: 3D printing (3DP), extrudability, limestone, natural pozzolans, printability, shape stability

DOI: 10.14359/51740895

Date: 6/11/2024

Abstract:
The emergence of 3D printing (3DP) technology in construction is limited by the overdependence on conventional Portland cement (PC). This is problematic in remote areas where procuring large quantities of raw materials requires sourcing from greater distances. Additionally, the rapid decline of coal combustion limits the availability of fly ash. This study aims to evaluate the feasibility of substituting high content (larger than 50%) of PC with natural pozzolans, including clay, pumice, and natural zeolite, as well as limestone filler that can be suitable for 3DP. The binder combinations were initially optimized to enhance packing density and robustness by evaluating the minimum water content and relative water demand of cement paste. A series of assessment methods, including slump flow loss test, rheological test, filtration test, axial deformation test, and unconfined uniaxial compression test, were carried out to determine the extrudability and shape stability of mortar made with the optimized binder candidates. Finally, the printability of these mixtures was validated using an extrusion-based 3D printer.