Graphene oxide-reinforced thin shells for high-performance, lightweight cement composites

Lightweight cement composites have been proposed in the literature, fabricated by controlling the cement coating onto 3D-printed polymer scaffolds to form submillimeter thin-shell structures. In this study, we adopted graphene oxide (GO) to reinforce the thin-shell structures and modify the weak interface between polymer scaffold and cement paste to produce high-performance, lightweight cement composites. The results indicated the thickness of thin shells was maintained constant for different GO dosages by controlling the workability of cement paste. GO significantly reduced high-porosity regions between the cement matrix and polymer scaffold, along with the microstructure refinement of the cement matrix and promoted the formation of low-density calcium-silicate-hydrates (from 50% to up to 66%). The GO shows a much higher reinforcing efficiency than traditional bulk cement, where the composites' compressive strength and specific energy absorption were increased significantly by up to 91% and 78%, respectively, with 0.01 wt% dosage. Compared with traditional lightweight concrete, the compressive strength of the GO-reinforced composites was increased by up to 20-fold. This study promoted understanding of the reinforcing mechanism of GO in thin-shell structures and demonstrated the effectiveness of GO for enhancing the performance of novel lightweight cementitious composites with a wide range of applications for load-bearing, energy absorption, decoration, and thermal insulation.