Methods for Measuring Plastic Shrinkage and Related Cracking of 3D Printed Concrete (2023-01)¶

Developments in the application of the 3D concrete printing (3DCP) technology in the construction industry over the past few years are providing a chance to increase productivity and cost efficiency. However, before reaching an industrial stage of the 3DCP technology several hurdles should be overcome. One of the major challenges is to guarantee high durability and long-life cycle of the printed elements. Since 3D-printed elements are subjected to very early and fast evaporation of the pore water, accelerated capillary pressure build-up may lead to severe plastic shrinkage and, consequently, a high cracking propensity of the 3D-printed elements. Durability and robustness would be severely impaired. Experimental quantification of the plastic shrinkage and related cracking is essential to identify appropriate mitigation strategies. The article at hand presents innovative approaches for quantification of the plastic shrinkage and related cracking of the printable cementitious compositions by means of contactless 3D digital image correlation technique. Various experimental setups were presented and their effectiveness for measurement of the plastic shrinkage and plastic shrinkage cracking were analysed.