Role of multiaxial state of stress on cracking of RC ties

• FE analysis of cracked RC ties through 1D, 2D, 3D discrete models.
• Comparison between experimental and numerical response of RC ties.
• Investigation of multiaxial stress diffusion in the concrete blocks between cracks.
• Improvement of numerical results through inclusion of damage in the bond–slip law.
• Improvement of numerical results through inclusion of secondary cracks.

This paper aims to investigate the role and effect of stress diffusion and bond deterioration in the analysis of reinforced concrete ties. Although tension ties seem to be basically in a uniaxial state of stress, after the onset of cracking the problem presents a multiaxial diffusion of stresses. In this paper, a uniaxial 1D numerical model has been compared with more sophisticated 2D and 3D Finite Element (FE) models, in order to investigate the different level of accuracy and information that can be attained considering or not the multiaxial state of stress. The obtained results show that the contribution of stress diffusion in concrete blocks between cracks has a certain importance for the evaluation of the global and local behavior of investigated tension ties, but it does not alter completely the response. Furthermore, the inclusion of damage in the bond–slip law due to the presence of “cone” cracks improves the description of the element behavior especially in the stabilized cracking stage. The same applies if thin secondary cracks are taken into account.