Behavior of Strengthened Composite Prestressed Concrete Girders under Static and Repeated Loading

Table 3

Cracking moment M_cr values for girders G1 and P1.

Girder	Mcr, kN·m experimental	Mcr, kN·m according to AASHTO LRFD and ACI	(Mcr,cal./Mcr,exp.), %
G1	1085	998	91.98
P1	1275	1194	93.65

M_cr is calculated using modulus of rupture (f_r) at date of test and including dead load effect according to M_cr = S_c (f_r + f_cpe), where S_c is the composite section modulus and f_cpe is the compressive stress in the concrete due to effective prestressing force.