The values of warping stress coefficient Cx and Cy are 0.8 and 0.5 respectively. The modulus of elasticity of concrete is 3 × 10⁵ kg/cm². Assume thermal coefficient of concrete = 10 × 10⁻⁶ per °C. The maximum temperature difference between the top and bottom of the slab during summer day and night is found to be 18°C. Estimate the maximum warping stress at the edge region.
- A21.0 kg/cm²
- B21.2 kg/cm²
- C21.4 kg/cm²
- D21.6 kg/cm²Correct
Solution
Concept
Edge warping stress
Formula
σ = Cx E α Δt / 2
Step-by-step solution
1. σ = 0.8 × 3×10⁵ × 10×10⁻⁶ × 18/2 = 21.6 kg/cm².
Explanation
Bradbury's formula.
Why the other options are wrong
Others do not follow.
Shortcut
C E α Δt/2.
Correct answer: D) 21.6 kg/cm²