σc	Compressive stress
εc	Compressive strain
σc,un	Unloading stress
εc,un	Unloading strain
εc,pl	Plastic strain
εcu	Ultimate compressive strain
σc,re	Reloading stress
σc1	Stress at unloading level 1 in Crisafulli [26]
σc2	Stress at unloading level 2 in Crisafulli [26]
βa	Constant in Crisafulli [26]
εc,re	Reloading strain
εcp	Peak strain
α, β	Constants in Subramaniam and Sinha [25]
σcp	Peak stress
A1, A2	Parameters in Crisafulli [26]
σc1	Stress at level 1
σc2	Stress at level 2
B1, B2, B3	Parameters in Crisafulli [26]
E0	Initial elastic modulus
Es	Secant modulus
A, D, k	Constants in Mendola and Papia [35]
Es,un	Unloading secant modulus
D1, D2	Constants in Sima et al. [27]
Es,re	Reloading secant modulus
δc−	Compression damage parameter in Sima et al. [27]
δcu−	Unloading damage parameter in Sima et al. [27]
n	Ratio of initial to secant modulus