In a doubly reinforced concrete beam, if ‘d’ is the effective cover to compression reinforcement, xm is depth of neutral axis, the strain at the level of compression reinforcement is given by:-
1
ec = 0.00035 \(\left( {1 - \frac{{{\rm{d'}}}}{{{\rm{xm}}}}} \right)\)
2
ec = 0.0035 \(\left( {1 - \frac{{{\rm{d'}}}}{{{\rm{xm}}}}} \right)\)
3
ec = 0.002 \(\left( {1 - \frac{{{\rm{d'}}}}{{{\rm{xm}}}}} \right)\)
4
ec = 0.0035 \(\left( {2 - \frac{{{\rm{d'}}}}{{{\rm{xm}}}}} \right)\)