DISEÑO DE VIGA DE CONCRETO REFORZADO ACI 318-11 Datos: L= f'c = fy = 3.5 m 28 Mpa 400 Mpa CM = CV = r= ∅estribo = #2 ∅= 2 0 Varillas Varillas #5 #0 4.0 kN/m 𝑀𝑢 = 𝑀𝑚𝑎𝑥 Se asume Se toma As= 3.83 cm2 > As_req = 2.8 cm2 𝑊𝑢 𝑙 2 = = 6.1 kN/m 8 𝜌 = 0.4𝜌𝑏 β 1 = 0.8500 𝜌𝑏 = 0.85 (f'c=28 Mpa) 𝑓′𝑐 600 𝛽1 = 0.030345 𝑓𝑦 600 + 𝑓𝑦 𝑓𝑦 = 16.807 0.85𝑓′𝑐 𝜌𝑚 𝑅𝑛 = 𝜌𝑓𝑦 1 − = 4.36 MPa 2 3 𝑀𝑢 𝑀𝑢 𝑏𝑑 2 = = 4𝑏 3 ∴ 𝑏 = = ∅𝑅𝑛 4∅𝑅𝑛 200 mm 𝑅𝑛 = 𝐴𝑠 = 𝜌𝑏𝑑 = 72.98 mm a= 32.23 mm 𝑎 𝛽1 𝑆 ∅𝑣𝑎𝑟𝑖𝑙𝑙𝑎 𝑑𝑡 = 𝑑 + + = 420.44 mm 2 2 𝑑𝑡 − 𝑐 𝜀𝑠 = 0.003 𝑐 εs = 0.03026 > 0.005 Comprobación de ubicación de refuerzo: 0.21 MPa 𝑆𝑏 = = OK 𝑏 − 2𝑟 − 2∅𝑒𝑠𝑡𝑟𝑖𝑏𝑜 − 𝑁𝑜. ∅𝑣𝑎𝑟𝑖𝑙𝑙𝑎 𝑁𝑜. −1 S b = 96.25 mm 0.00053 > ∅varilla = 15.6 mm, 25 mm Cumple 2 42.40 mm 𝐴𝑠,𝑚𝑖𝑛 = 0.25 𝐴𝑠 𝑓𝑦 0.85𝑓′𝑐 𝑏 c = 37.92 mm y d = 400 mm 𝑀𝑢 = ∅𝑏𝑑2 1 2𝑚𝑅𝑛 𝜌= 1− 𝑚 𝑓𝑦 𝑎= 𝑐= 𝑚= Tomar b = OK Comprobación de tensión: ρ = 0.012138 A s,min = A s,min = 0.90 Para sección controlada por flexión y tensión Usar con 𝑊𝑢 = 1.2𝐶𝑀 + 1.6𝐶𝑉 Wu = 02 kN/m 01 kN/m 30.0 mm ℎ = 𝑑𝑡 + 𝑓′𝑐 1.4 𝑏𝑤 𝑑 ≥ 𝑏 𝑑 𝑓𝑦 𝑓𝑦 𝑤 264.58 mm2 280.00 mm2 h= ∅𝑣𝑎𝑟𝑖𝑙𝑙𝑎 + ∅𝑒𝑠𝑡𝑟𝑖𝑏𝑜 + 𝑟𝑒𝑐𝑢𝑏𝑟𝑖𝑚𝑖𝑒𝑛𝑡𝑜 2 464.50 mm Tomar b = 200 mm y Controla h = 450 mm