Cracking analysis of RC ties based on the effect of primary and internal cracks

A mathematical modelling, named as general model, is here proposed for the calculation of the maximum crack width under static loading accounting for both primary and internal cracks. This model is based on the slip-theory. The main results obtained with the general model allow to improve the calculations for the average bond stress and the mean deformation beyond the provisions included in fib Model Code 2020 and Eurocode 2. A simplified calculation method is also developed showing results very similar to those obtained by the general method. Moreover, the effect of the concrete cover is incorporated into the modelling, upgrading both general and simplified models in a combined theory that considers both slip- (relative displacement between steel and concrete) and no-slip- (perfect bond) conditions. Finally, the theoretical results of crack spacing and crack width obtained with the combined theory for the general model are compared with the experimental data obtained on RC ties.