The creep behavior equation of NASC can be expressed by Eq. (48).
Because the strain in both fiber and interface is much smaller than that in matrix, only the strain in matrix is considered under compressive load. Then the stress-strain relationship of the third part in Fig.6 resulted from the resilience constitutive equation is in the form
The stress-resilience equation of NASC is in the form
The detailed derivation of Eqs. (7)-(51) can be found elsewhere (Zhu, 2008).