# 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

**Notation**

_{c}= allowable compressive stress of concrete

f

_{s}= allowable tesnile stress of steel reinforcement

f'

_{c}= specified compressive strength of concrete

f

_{y}= specified yield strength of steel reinforcement

E

_{c}= modulus of elasticity of concrete

E

_{s}= 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

A

_{s}= area of steel reinforcement