Fig. 6 depicts the stress–strain curves of the tested specimens. A
post peak descending branch is observed in the stress–strain
curves of all the confined specimens and the compressive strength
is reached before the rupture of ferrocement jacket. If the stress–
strain curve ends at a concrete stress higher the compressive
strength of unconfined concrete, the ferrocement confinement is
still sufficient to enhance the strength [24]. However, if the curve
terminates at a concrete stress lower than the compressive
strength of unconfined concrete, the specimen is said to be insufficiently
confined [24].
For specimens confined with single layer mesh ferrocement, the
stress–strain curves of larger specimens terminate at a lower concrete
stress than the compressive strength of unconfined concrete.
Thus, all the LS–SL specimens are insufficiently confined. Similar
behavior is also observed in one SS–SL and two MS–SL specimens.
However, all the specimens confined with double layer mesh ferrocement
jacket have higher rupture strength than the unconfined
compressive strength of concrete irrespective of the specimen size.
Therefore, it can be said that the specimens confined with double
layer mesh ferrocement are sufficiently confined