Evaluation of Fresh, Hardened, and Durability Properties of Three-Dimensional Concrete Printed Pipes (2025-11)¶

Additive construction augments the laborious construction of structural concrete; however, its implementation remains mostly limited to building envelopes. Culvert construction benefits from alternative methods due to the high demand for transportation infrastructure. In this study, extrusion-based three-dimensional concrete printing (3DCP) is developed for the first time for culvert construction. Large-scale unreinforced concrete pipes were printed, and the early-stage (for example, buildability), mechanical, and durability properties of two commercially available 3DCP materials were determined. Additionally, the specimens were tested structurally and exceeded the expected structural performance (by approximately an average of 32%) under the three-edge bearing test. However, the desired durability was not met due to the porosity of the specimens. The mixture design with microfibers exhibited marginally higher compressive and tensile strength but did not meet durability criteria similar to non-fiber material. Results indicated the 3DCP feasibility for pipe culvert construction and mapped further direction for widespread implementation and addressing concrete pipe durability issues.