Characterization of 3D printing mortars made with OPC/CSA

Abstract

Printable mortars used in 3D printing of cementitious materials must have rheological behaviour and setting rigorously controlled. In this research, mixes made of two types of cement, ordinary Portland cement (OPC) and Calcium Sulfoaluminate cement (CSA) are adopted to control the printability of a mortar. Extrudability, buildability and comparable compressive strength to that of a traditional mortar are the specifications required by the printable mortar. Different mixes of OPC/CSA cement pastes (ranging between 0 and 10% of CSA) and 2 mixes of OPC/CSA mortars (0 and 7% of CSA) are studied. The cement pastes are studied by isothermal calorimetry and rheometer. Heat of hydration and cement pastes' yield stress increase with the dosage of CSA in the mix. A mortar made out of 7% CSA in previous article [1] is then tested in laboratory and their behaviour is compared to the results of the cement pastes.