Effects of bamboo treatment on physical‐mechanical properties and concrete bond strength

Abstract Bamboo is increasingly used in construction due to its low density, rapid growth, and high tensile strength, but its water absorption and expansion when in contact with fresh concrete remain key challenges. This study examined the effects of different treatments (boiling water, sodium hydroxide, boric acid) and hydrophobic agents (Aquapuls, Nanosil, Diotrol, PL04X, Polimer Sement, Mega Stone, Sikador‐32) on bamboo's physical/mechanical properties, including tensile strength, strain, modulus of elasticity, and concrete bond strength (via pull‐out tests). Results showed that boric acid treatment reduced mass (3.6%), increased volume (6.8%), lowered density (0.08 g/cm 3 ), improved tensile strength (~36%), and, following 28 days of water immersion, decreased expansion (~2%). In contrast, sodium hydroxide/boiling water had opposite effects. Among hydrophobic agents, Mega Stone and Sikador‐32 reduced water absorption by 75.8% and 75.4%, respectively, and increased bond strength by 713% and 568%, demonstrating that combining boric acid with selected hydrophobic treatments can effectively enable bamboo's use as concrete reinforcement.