Assessment of the properties of interface-modified bamboo aggregates for sustainable concrete construction

Abstract

To alleviate the serious loss of gravel resources, reduce carbon emissions and improve the sustainability of concrete materials, this study presents an innovative approach to develop a novel eco-friendly bamboo aggregate concrete. The proposed method involves utilizing the abundant and renewable Phyllostachys edulis (Moso) bamboo to create a new type of bamboo aggregate, as a substitute for conventional gravel aggregates. This study modified the bamboo surface using a composite effect of epoxy mortar and polyurethane adhesive to realize the direct application of bamboo aggregates. Compared to unmodified and polyurethane-modified bamboo, epoxy mortar-modified bamboo showed significantly improved physical and mechanical properties. Anti-corrosion properties tests revealed that the modified bamboo, especially epoxy mortar-modified bamboo, was less affected by acidic and alkaline corrosion than the unmodified bamboo and the mass loss rate was almost zero. In the early stages of alkaline corrosion, the strength of the bamboo increased, and then began to decrease after 28 d. The removal of the outer green bamboo significantly improved the adhesion of the adhesive to the bamboo surface, as confirmed by pull-out tests. A sufficient bonding area between the epoxy mortar-modified bamboo and the cement matrix remained after compression damage, whereas obvious debonding behavior between the cement matrix and unmodified and polyurethane-modified bamboo was observed. In summary, epoxy mortar modification significantly improved the comprehensive performance of bamboo aggregates. This study is expected to help improve the utilization rate of bamboo, promote bamboo concrete, and develop sustainable materials.