$a$	initial crack length
$a_c$	effective elastic crack length
$A_{tig}$	area of the broken ligament
$b$	thickness of specimen
$c$	height of specimen
$c_i$	initial compliance coefficient
$CMOD$	crack mouth opening displacement
${CMOD}_0$	CMOD value when the bearing capacity drops to 20% of the peak load
$\mathrm{CTOD}$	crack tip opening displacement
$D$	dry
$E$	elastic modulus
$\mathrm{ECC}$	engineered cementitious composites
$f_{0i}$	initial value of the transverse fundamental frequency of specimen
$f_{ni}$	transverse fundamental frequency of the specimen after n freeze–thaw cycles
$FT$	freeze–thaw
$G_I$	nominal fracture energy
$G_{I(SW-(20\left)\right)}$	nominal fracture energy of the SW-(20) group
$G_{I(SW-(-20\left)\right)}$	nominal fracture energy of the SW-(−20) group
$h_0$	thickness of the blade used to fix the clip
$h$	height of specimen
$K_{IC}^{ini}$	initial fracture toughness
$K_{IC}^{un}$	nominal unstable fracture toughness
$L$	length of specimen
$\mathrm{LS}$	linearly superimposed
$m_1$	mass of specimen
$m_2$	weight of the loading head not fixed on the testing machine
$M_0$	initial mass of specimen
$M_1$	mass of the specimen after soaked in water
$N$	number of cycles
$P$	applied load
$P_{ini}$	initial cracking load
$P_{max}$	peak load
$P_i$	dynamic elastic modulus of the specimen after freeze–thaw cycles
$S$	net span of the test specimen
SW	saturated water
SSW	semi saturated water
T	temperature
W0	mass of the specimen after n freeze–thaw cycles
Wn	mass loss rate of the specimen after n freeze–thaw cycles
$\delta$	midspan deflection
$\alpha$	relative crack extension length and $\alpha =(a+h_0)/(h+h_0)$
${\alpha }_c$	relative crack extension length and ${\alpha }_c=(a_c+h_0)/(h+h_0)$