Topology optimization of 3D printed concrete beams: a study of strength to weight ratios

Abstract

The construction industry is a major contributor to global energy consumption and CO₂ emissions, necessitating material-efficient design solutions aligned with green building standards such as IGBC and GRIHA. This thesis explores the integration of topology optimization with 3D concrete printing (3DCP) to design and fabricate optimized concrete beams that achieve superior strength-to-weight ratios while minimizing material usage. A concrete beam of dimensions 500 mm × 100 mm × 20 mm was optimized using ANSYS Workbench for minimum compliance, and the resulting design was traced and adapted for 3D printing. A suitable 3D printable concrete mix was developed through trial-and-error, ensuring essential properties like buildability and extrudability. The study further compares the structural performance of topology-optimized beams against beams with alternative infill patterns (S-shaped and N-shaped) and conventional mould-cast beams. Experimental validation involved four-point flexural tests to assess failure loads, deflection behaviour, and material efficiency. Results indicate that the topology-optimized 3DCP beam achieved an 8.04% improvement in strength-to-weight ratio compared to conventional beams, demonstrating the viability of combining computational design tools with advanced manufacturing techniques. This research highlights the potential of topology optimization in enhancing the sustainability of concrete structures by reducing material use without compromising structural integrity. The findings underscore the role of commercial FEA tools, such as ANSYS, in facilitating optimized designs compatible with 3DCP technology, paving the way for greener, more efficient construction practices.