ACI 318

Reinforced Concrete Design by WSD Method

Working Stress Design is called Alternate Design Method by NSCP (National Structural Code of the Philippines) and ACI (American Concrete Institute, ACI).

Code Reference
NSCP 2010 - Section 424: Alternate Design Method
ACI 318 - Appendix A: Alternate Design Method


fc = allowable compressive stress of concrete
fs = allowable tesnile stress of steel reinforcement
f'c = specified compressive strength of concrete
fy = specified yield strength of steel reinforcement
Ec = modulus of elasticity of concrete
Es = modulus of elasticity of steel
n = modular ratio
M = design moment
d = distance from extreme concrete fiber to centroid of steel reinforcement
kd = distance from the neutral axis to the extreme fiber of concrete
jd = distance between compressive force C and tensile force T
ρ = ratio of the area of steel to the effective area of concrete
As = area of steel reinforcement


Subscribe to RSS - ACI 318