FORMULARIO CONCRETO ARMADO 1

PRIMER PARCIAL

Resistencias de cementos:

3000 Psi 210 kg/cm2

21 MPa

4000 Psi 280 kg/cm2

28 MPa

5000 Psi 350 kg/cm2

35 MPa

6000 Psi 420 kg/cm2

40 MPa

Grados de acero:

G-40 40000 Psi 2800 o 2810 kg/cm2

G-60 60000 Psi 4200 kg/cm2

G-50 50000 Psi

Nomenclatura del acero de refuerzo:

Barra # Barra # ϕ As cm2

# barras qq Φ cm

--- No. 2 2/8 “ ¼ “ 0.32 30 ---

10 No. 3 3/8 “ 3/8 “ 0.71 13.33 0.95

13 No. 4 4/8 “ ½ “ 1.27 7.50 1.27

16 No. 5 5/8 “ 5/8 “ 2.00 4.80 1.59

19 No. 6 6/8 “ ¾ “ 2.85 3.33 1.90

22 No. 7 7/8 “ 7/8 “ 3.88 2.45 2.22

25 No. 8 8/8 “ 1 “ 5.07 1.87 2.54

29 No. 9 9/8 “ 9/8 “ 6.42 1.48 2.86

32 No. 10 10/8 “ 5/4 “ 7.94 (8.19) 1.20 3.18 (3.23)

36 No. 11 11/8 “ 11/8” 9.57 (10.06) 0.99 3.49 (3.58)

39 No. 12 12/8 “ 6/4 “ o 3/2 “ 11.40 0.83 5.81

Método #2

Predimensionamiento de vigas

Mu 0.90As fyd Asfy

1.7f cb

Simple apoyo L

16

1 extremo continuo L

18.5

Ambos extremos continuos L

21

Voladizo L

8

Método #1: Iteraciones

Fórmulas para tabla

Método #3: Directo

Acero de la viga (Asviga):

Rango de aceptación para porcentaje de acero:

1 a Asfy

0.85f cb As 0.85af cb

fy

2 Mu As fy d a

2 As Mu

fyd a

2

As b d 2 d b2 Mub

0.003825f c 0.90 f c

fy

As Asvigacm2

Donde : Mu kg m

As cm2

b,d cm

f c, fy kg

cm2

min viga max

min 14.1

fy%SI

min 200

fy%Ingles viga

Asviga

bd%

b 0.85 1 f c

fy 6120

fy6120%SI

b 0.85 1 f c

fy 87000

fy87000%Ingles

max 0.5 b%

Área de acero:

Armadura de acero con requisitos sísmicos en cada superficie:

Asmin Asviga Asmax

Asmin min b d

Asviga viga b d

Asmax max b d

Asminsup

Asmin

2 barras No. 3

33% As

El mayor de los 3

Asmininf

Asmin

2 barras No. 3

50% As

50% As

El mayor de los 4