Quantitative Comparison of Elastic Modulus Measurement Techniques in Early-Age 3D Printable Mortar (2024-09)¶

This research investigates the early-age development of Young’s modulus in 3D printable mortar mixes, emphasizing the critical role of material properties in the success of 3D concrete printing technologies. Through a synthesis of findings, the study utilizes ultrasonic pulse velocity (UPV), compression, and microindentation tests to examine how water-to-cement ratio, aggregate size, paste volume, and the use of accelerators influence stiffness development within the first 24 h after mixing. The analysis highlights significant difference in measured Young’s moduli across the three testing techniques. Particularly at early stages, ultrasonic test shows considerably higher values compared to compression test. These differences underscore the need for careful selection of testing methods and cautious interpretation of data when assessing the mechanical properties of 3D printed concrete. The research also reveals that lower water-to-cement ratios and the addition of accelerators lead to quicker development of yield strength, compressive strength, and Young’s modulus, delivering valuable insights into optimizing 3D printing parameters for enhanced construction processes. This study advocates for further investigation into the observed discrepancies between measurement techniques at early age, aiming to refine our understanding of material behavior and improve the application of digital fabrication in construction.