Advanced Strategies for Comfort and Mechanical Performance of 3D-Printed Concrete Wall Structures: A State-of-the-Art Review

Abstract

3D-printed structures are an important direction in green construction, but layer-wise deposition forms interlayer interfaces that strongly influence the axial compressive performance of printed walls. This paper reviews interlayer bonding, anisotropy, strengthening strategies, and component-level load-bearing behavior of 3D-printed concrete walls within a “material–process–interface–component” framework and distils three main insights. First, anisotropy ranking is not universal. Although previous studies often report higher strength in the X-direction, anomalous cases and differences in direction definition indicate that this ranking is jointly affected by material systems and process parameters; therefore, simple deterministic statements should be avoided. Second, this review synthesizes the concept of an “optimal intervention zone” to explain why strengthening effectiveness does not increase monotonically with intervention intensity, but is influenced by interlayer bond strength, stress distribution, and reinforcement orientation. Beyond a reasonable range, new weak links may be introduced. Third, 3D-printed concrete walls and masonry structures both exhibit load-bearing behavior governed by horizontal weak planes. Masonry systems may therefore provide a useful design reference, although further development is required to reflect printed-interface characteristics. Overall, the key bottleneck is the lack of a cross-scale transfer chain from material interfaces to component performance. Cross-scale predictive models, interlayer bond testing and grading, and interface-performance-centered standardized design are important pathways toward engineering application.