Tiêu đề 38 RCD - Development Length.pdf ✅

Confining Reinforcement ψr For 90-degree hooks of 36 mm∅ and smaller bars: 1. Enclosed along ldh within ties or stirrups perpendicular to ldh at s ≤ 3db 2. Enclosed along the bar extension beyond hook including the bend within ties or stirrups perpendicular to lext at s ≤ 3db 0.8 Other 1.0 425.4.3.3. For bars being developed by a standard hook at discontinuous ends of members with both side cover and top (or bottom) cover over hook less than 65 mm (a) through (c) shall be satisfied: (a) The hook shall be enclosed along ldh within ties or stirrups perpendicular to ldh at s ≤ 3db, (b) The first tie or stirrup shall enclose the bent portion of the hook within 2db of the outside of the bend, (c) ψr shall be taken as 1.0 in calculating ldh in accordance with Section 425.4.3.1.(a) where db is the nominal diameter of the hooked bar. For hooks and bends: Table 425.3.1. Standard Hook Geometry for Development of Deformed Bars in Tension Type of Standard Hook Bar Size Minimum Inside Bend Diameter Straight Extension, lext (mm) Type of Standard Hook 90-degree hook 10 mm Φ through 25 mm Φ 6db 12db 28 mm Φ through 36 mm Φ 8db 40 mm Φ and 58 mm Φ 10db 180-degree hook 10 mm Φ through 25 mm Φ 6db Greater of 4db and 65 mm 28 mm Φ through 36 mm Φ 8db 40 mm Φ and 58 mm Φ 10db