Análise da sinergia entre cimento, metacaulim e calcário na capacidade de impressão de argamassa LC3

Abstract

3D concrete printing (3DCP) is a technology that is gaining more and more attention in the industry; however, due to the rheological complexities of mortar and with high cement consumption, over 330 kg/m³, maintaining sustainability and economy becomes challenging. In this way, the recent LC³ cement has been showing promise for application in 3DCP, due to the reduction in clinker content up to 45% and because it has the characteristics in the fresh state necessary for printing mortar. However, the effects of different ratios of ternary cement components – Portland cement (CP), metakaolin (MK) and limestone (FC) – on the rheological and mechanical properties of 3DCP mortars are still not fully understood, especially when regional differences in raw materials are taken into account. Therefore, this study aims to evaluate the impact of different Portland cement, metakaolin and limestone contents on printability - analysis of the fresh and hardened states. Ten mixtures with different contents were generated by a mixture design of experiments and a reference mortar with 100% Portland cement was added. Fluidity tests were carried out over time, squeeze-flow, specific mass in the fresh state, compressive strength of 14x19x19 cm blocks, compressive strength and flexural tensile strength of extruded and conventionally molded mortar prisms. In the end, it was found that the MK content can be maximized and the FC content minimized, while still obtaining a performance similar to the standard LC³. In addition, LC³ mixtures with cement contents as low as 25% can be used in 3DCP techniques to meet mechanical requirements.