2024/06/07 by Michal Hlobil, Luca Michel, Hlobil, Michal +5
Engineering · #Additive Manufacturing and 3D Printing Technologies #BIM and Construction Integration #FOS: Physical sciences #Innovations in Concrete and Construction Materials #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2406.05238
openalex publication_date 2024/06/07 · openalex created_date 2024/06/12 · openalex updated_date 2026/07/28
Cold joints in extruded concrete structures form once the exposed surface of a deposited filament dries prematurely and gets sequentially covered by a layer of fresh concrete. This creates a material heterogeneity which lowers the structural durability and shortens the designed service life. Many factors concurrently affect cold joint formation, yet a suitable tool for their categorization is missing. Here, we present a computational model that simulates the drying kinetics at the exposed structural surface, accounting for cement hydration and the resulting microstructural development. The model provides a time estimate for cold joint formation as a result. It allows us to assess the drying severity for a given structure's geometry, its interaction with the environment, and ambient conditions. We evaluate the assessed factors and provide generalized recommendations for cold joint mitigation.