Sustainable mix design for 3D printable concrete

Abstract 3D concrete printing is a new building process that has great potential for the construction industry in terms of optimizing construction time, cost, design flexibility, error reduction, and environmental factors. The most influential factor that determines successful printing is the concrete mix. This study focuses on designing a sustainable 3D printable mix and further examining its fresh and hardened mechanical properties. This study concentrated on the performance requirements for 3D printable concrete, which include printability, extrudability, and buildability. The trail mixes are conducted using cement, fine aggregate, and water. Crucial components like GGBS, fly ash, and crystalline silica are replaced with cement to improve the performance of the concrete mix. The mechanical and fresh properties of the 3D printable mix are examined using compressive and unconfined uniaxial compression tests. The early-age strength of the trail mixes was assessed using the unconfined uniaxial compression test. The findings showed that the best mix could withstand deposited layers for 60 minutes after adding water to the binder. The mix containing cement, fly ash, GGBS, silica, sand, and water is the optimal mix. The compressive test of the printed specimen revealed that it attained 44.5% and 23% more strength compared to other mixes. The inclusion of crystalline silica is the reason behind increased compressive strength and an inter-layer bond between the layers.