Development of rapid set mortar for additive manufacturing

The study presents the development results of blended cement mortars for additive manufacturing. The goal was to achieve a balanced rheological behaviour of the fresh mixture through optimal granulometry, suitable grain shape and the choice of micro-admixtures. The article closely describes the granulometric and rheological characterization of the proposed ternary and quaternary blended mortar mixtures with various SCM's. The print quality and shape stability of the promising mortars and the researched 3DP mixes were evaluated during incremental layering for comparison. The performed experiments confirmed that the mixtures containing blast furnace slag, quartz powder and metakaolin are more plastic and allow faster layering in height. The slaked lime-enriched mixture has excellent plasticity and is able to resist deformation during overlaying, the printed layers are without surface defects. The small addition of polypropylene fibre (0.08 wt.%) improves the plasticity and shape retention ability.