3D printed polymeric formwork for lattice cementitious composites. (November 2021) - Song, Jian
Abstract: How to design energy-efficient building materials, theoretically requiring a balance of mechanical properties and thermal conductivity, remains a crucial challenge in construction & building fields. Recently there is an increased interest in using 3D concrete printing technology to automatically manufacture complicated and customized constructions. Nevertheless, majority of printed constructions are still solid and have a low quality in the interface performance. Inspired by the lightweight lattice architecture, 3D core-framework lattice cementitious composites (CS-LCCs) is proposed in this work, which consists of printed polymeric framework and cement mortar. Results show that although the average compressive strength of CS-LCCs is lower than that of the cubic sample fabricated using the cement mortar (40 × 40 × 40 mm 3 ), the specific strength of CS-LCCs approaches that of cubic one. The ductility of CS-LCCs is obviously improved due to the effect of polymeric framework. According to the test and finite element analysis, a hinging and stretching couple deformation mechanism is used to elaborate the deformation mechanism of CS-LCCs. Additionally, the CS-LCCs also exhibit low thermal conductivities at various temperatures owing to the ordered porous characteristic of lattice. Graphical abstract: Image 1 Highlights: ● A core/shell lattice-inspired cementitious composites is proposed. ● High specific strength and ductility are obtained owing to the effect of polymeric shell. ● Multi-crack propagation mode and deformation mechanism are elaborately discussed. ● Low thermal conductivity is achieved compared to that of the counterpart solid materials.