On the Calibration of a Numerical Model for Concrete-to-Concrete Interface

Abstract

The study was devoted to the numerical modelling of concrete-to-concrete interfaces. Such an interface can be found in many modern composite structures, so proper characterisation of its behaviour is of great importance. A strategy for calibration of a model based on cohesive finite elements and the elastic-damage traction–separation constitutive law available by default in the Abaqus code was proposed. Moreover, the default interface material model was enhanced with the user-field-variables subroutine to include a real strength envelope for such interfaces. Afterwards, the modelling approach was validated with numerical simulation of the most popular tests for determining the strength characteristics of concrete-to-concrete interfaces: three-point bending beam with a notch, splitting bi-material cubic specimens, and slant-shear tests. The results of own pilot studies were used as well as those reported by other researchers. The performed simulations proved the accuracy of the proposed modelling strategy (the mean ratio of ultimate forces obtained with numerical models and from experiments was equal to 1.01). Furthermore, the presented examples allowed us to better understand the basic test methods for concrete interfaces and the observed mechanisms of failure during them.

A Detailed Numerical Model for a New Composite Slim-Floor Slab System

“…Special attention is paid to the modelling the interfaces between different parts of the structural system. The main assumptions for this issue have been described earlier in the paper [28]. It is based on cohesive elements, which can more accurately reproduce the behaviour of concrete-to-concrete interfaces.…”

“…In this paper, cohesive elements were used instead of more common contact elements. They are able to correctly reproduce the concrete-to-concrete interfaces [28] as well as being much more numerically efficient due to the lack of contact pairs detecting algorithms. The Abaqus code enables users to apply viscous regularisation for cohesive elements which makes the incremental-iterative process very stable even for the range of significant delamination.…”

“…The calibration strategy has already been presented in the paper [28] and is summarised in Table 1. f ctm Uniaxial tensile strength…”

“…For prestressing tendons, a linear elastic model is adopted. In the case of interface elements, the traction-separation law available by default in the Abaqus code is used with modifications proposed in paper [28]. It is formulated in the framework of damaged elasticity.…”

“…The damage initiation criterion controls the onset of the damage state [42]. The quadratic nominal stress criterion with the modification described in-detail in [28] is selected in this study. It can be expressed as follows:…”