The influence of biochar shape on cement-based materials

Biochar-containing cement composites have attracted increasing interest in recent years due to the possibility of reducing the environmental impact linked to cement. They can also improve the mechanical properties and the electrical conductivity of cement-based materials. One parameter that can affect the mechanical performance of biochar-containing cement composites is the morphology of the biochar. While it is reasonable to expect a different behaviour for different shapes (sheet-, sphere- or rod-shaped), a full understanding is yet to be achieved of the competing effects of aspect ratio, morphology and composition linked to the specific biochar source. This study shows that biochar can improve the mechanical properties of cement-based composites: 1 wt% of biochar improves compressive strength and flexural strength by 7% and 15%, respectively. The results presented in this study confirm that biochar has a positive effect on both the mechanical and environmental behaviour of cement-based materials.