Fig. 5(a) and (b) illustrates the different stages typically
observed on axial stress–strain curves of the specimens of the present
study with and without post-peak strain softening regions,
respectively. The notation and definitions introduced in this figure
are used consistently throughout the discussion presented in this
paper. The summary of the key experimental results are shown
in Tables 6 and 7. Table 6 presents the recorded axial stresses,
which include: the compressive strength (f0
cc), initial peak stress
(f0
c1) that marks the point of transition from the initial ascending
branch to the softening region of the second branch (Fig. 5(a)),
stress at plateau formation (f0
c2) that marks the point of transition
from softening to hardening region on the second branch of the
stress–strain curve (Fig. 5(a)), and strength enhancement ratio (f0