Effect of Recycled Aggregate Use on the Fresh State Properties of Limestone Calcined Clay Cement (LC3) Mortars (2025-04)¶

Recently, issues such as the global climate crisis, environmental sustainability, and resource efficiency have become important issues in the construction industry. This situation requires reviewing the environmental impacts of the production and use of construction materials and developing more sustainable alternatives. Accordingly, using recycled concrete aggregate from construction and demolition waste is an environmentally friendly and energy-saving solution. The literature contains studies on using recycled aggregate in standard cement systems. However, its use in alternative cement systems is a new topic. Limestone calcined clay cement (LC3) is a promising cement type for reducing harmful greenhouse gas emissions from cement production. It is an environmentally friendly solution, especially in mixtures that consume intensive cement, such as 3D printable concrete. In this context, the aim of the study was to use recycled aggregate by replacing it with fine aggregate in 3D printable mortar mixtures prepared using LC3 and to investigate the effect of recycled concrete aggregate on fresh state properties. For this purpose, the recycled aggregate was replaced with fine aggregate at rates ranging from 12.5% to 37.5%, and its effect on the slump and slump flow diameter values of fresh mortars and, accordingly, its suitability for the consistency parameters required for 3D printing were evaluated.