Question

For a masonry section of width 600 mm with zero tensile strength and a linear stress–strain response, the minimum eccentricity (in mm) at which cracking begins is \(\underline{\hspace{2cm}}\).

Hint:

For zero tensile strength materials (like masonry), cracking starts when the compressive stress block just touches one edge—this gives the classic $e=b/6$ limit.

Answer 1

Correct Answer: 103 - 97

For a rectangular section of width \(b = 600\) mm, zero tensile stress implies that cracking begins the moment the stress at one edge becomes zero. Stress distribution under compression with eccentricity \(e\) becomes zero at the extreme fiber when \[ e = \frac{b}{6}. \] Thus, \[ e = \frac{600}{6} = 100\ \text{mm}. \] Final Answer: \[ 100\ \text{mm} \]