Experimental Study on Water Penetration and Thermal Resistance of Large-Scale 3D-Printed Cementitious Walls (2025-03)¶

3D concrete printing is an innovative technology in construction, offering a faster and cost-effective way to build houses and other structures. However, challenges such as the increased presence of voids in interlayer joints and higher porosity in the printed material may negatively affect the performance of 3D-printed building envelopes. Hence, in the first phase of this study, the performance of large-scale 3D-printed cementitious walls was evaluated under wind-driven rain conditions. Wall specimens with cold joints, which were built and cured during the construction of an actual 3D-printed concrete building, were tested to evaluate the real-world performance of such building envelopes against wind-driven rain. In the second phase, the thermal resistance of printed walls with different printing patterns and insulation configurations was examined. The study found that although 3D-printed concrete walls are highly vulnerable to driving rain, the inclusion of an air cavity between two wythes effectively prevents rainwater from infiltrating into the building. Additionally, uninsulated 3D-printed walls with regular hollow sections and zig-zag patterns demonstrated higher thermal resistance compared to walls made of traditional concrete masonry units (CMU). The study also found that a printed concrete wall with regular hollow section (core) with insulation in the hollow core is able meet the requirement of thermal resistance specified by Canadian building code.