In a doubly reinforced concrete beam, if 'd' is the effective cover to compression reinforcement, xm is the depth of neutral axis, the strain at the level of compression reinforcement is given by:
1
\(e_c=0.00035[{1-{d'\over x_m}}]\)
2
\(e_c=0.0035[{1-{d'\over x_m}}]\)
3
\(e_c=0.0002[{1-{d'\over x_m}}]\)
4
\(e_c=0.00035[{2-{d'\over x_m}}]\)