Crack Infrastructure Design Suite 2013

The second analytical model involved implementing an iterative moment-curvature solution by using the constitutive models of each element based on material testing. Refer to McRory [44] for detailed design calculations of the two design approaches. The steel-reinforced model was performed in accordance with the AASHTO LFRD flexural design requirements outlined in Article 5.6.3 [39]. Since the reinforcement ratio was sufficient in the GFRP sections to ensure a concrete crushing failure, the requirements of Article 2.6.3.2.2 of the AASHTO LRFD Design Guide for GFRP were used to obtain the flexural capacity of the GFRP-reinforced section [39]. Finally, the recommendations provided in Sections 4.7 and 4.9 of the ACI 544.4R-18 [42] Guide for Design with FRC were followed, although instead of using a variable stress-crack width relationship for the FRC, the rigid-plastic model for FRC detailed in subclause 5.6.3 of the fib Model Code [51] was applied to the entire tensile region. Equation (1) describes the ultimate residual strength in the section as a function of the residual flexural tensile strength at a crack opening of 2.5 mm: