Phosphorous slag-based geopolymer cement incorporate with mullite for 3D printing application

Abstract

In successful 3D printing, the primary key is the proper binder and correct formulation, which leads to the printable mortar. In this work an attempt has been made to fabricate a 3D printable phosphorous slag-based geopolymer concrete with the incorporation of mullite and precisely determined liquid-based activator. The results showed that with the increase of Si/Na from 0.2 to 0.6 increases initial setting time and open time. Presence of mullite resulted in more orientation of Al(IV)-O vibration band in the produced geopolymer matrix so that the maximum compressive strength has achieved in the sample incorporated with mullite and with Si/Na of 0.4 in the activator. The designed geopolymer paste is following the Herschel-Buckley model and show thixotropic behavior, which is useful rheological property for 3D printing applications especially for continuous extrusion and having a desirable layer-by-layer printing.