3.2 Bond mechanism ■ Deformed Bar-Mechanical interlock Radial crack reaching specimen surface 40 Splitting of specimen Crushed 30 concrete Forming new slip surface 20 tc=0.80.85tu Internal diagonal crack occurrence 51=0.350.4mm 10 Local deformation of concrete in the vicinity of ribs 0 0.1 0.2 0.3 0.4 0.5 si/mm 土本工程学院10 3.2 Bond mechanism ◼ Deformed Bar ─ Mechanical interlock Local deformation of concrete in the vicinity of ribs Internal diagonal crack occurrence Crushed concrete Forming new slip surface Radial crack reaching specimen surface Splitting of specimen τ cr = 0.8~0.85 τ u sl = 0.35~0.4 mm