Numerical Analysis of Flexural Behaviour in 3D-Printed Snap-Fit Interlocking Concrete Specimens Incorporating Frictional Interactions (2026-04)¶

3D Printable Concrete (3DPC) is an emerging trend in the construction industry where three-dimensional computer aided models are printed using additive manufacturing principle. The advancement of 3D printing concrete is hindered by challenges in precise control over the printing of structures on a larger scale or longer spans. To overcome this challenges of the 3DPC structures, the 3DPC beam, in the study, is segmented into smaller sections and snap fit interlocking mechanism is utilized to offer more design flexibility and customization. Two primary interlock systems include (i) Flat interlock and (ii) Fillet interlock were used to investigate the flexural performance of 3DPC beams connected with these interlocks under 3-point bending, 4-point bending and cantilever action. The segmented structures were modelled as 3D solid elements using finite element modelling (FEM) software Abaqus and interlock mechanism was developed by using the coefficient of friction of 0.8 between the concrete surfaces to develop a mortar free connection system. Flat interlocked beams exhibited a 64% higher load-bearing capacity than fillet interlocks under three-point bending tests. Double interlocked beams demonstrated a 37% strength enhancement over single interlocked variants under four-point bending. The interlocked segmented 3DPC beams exhibit bending behaviour influenced by transverse displacement, stress distribution, and load-bearing characteristics, aligning with reinforced concrete systems under flexural loading. The study showcases the feasibility of adopting these interlocked beams by analysing the failure patterns of different interlocking systems by comparing single interlock surfaces with double interlock surfaces of the designed interlock systems.