Influence of surface based cohesive parameters on static performance of concrete composite T-shaped beams

Abstract

The study presented constitutes the next step of authors’ investigations on the concrete composite T-shaped beams. The comparison of the failure modes and crack patterns of numerical models and beams tested was performed previously. In this paper, analyses concentrate on determination the proper values of cohesive surface parameters ensuring the high conformity of deformation and strains of the numerical model to the experimental results. In the particular series of beams the interfaces between concrete parts are varied as follows: reinforced joint with normal and tangential interactions only (BZ/S2/A), non-reinforced joint with adhesion (BZ/P), and reinforced joint with adhesion (BZ/P+S). Material properties used in numerical model are based on obtained in the laboratory ones. Furthermore, the ‘traction–separation’ law in the ABAQUS software defining the cohesion surface is used and analysis of the cohesive parameters response to interface roughness is carried out. The results show a strong dependence between the cohesion surface parameters and the response of the composite beam. A very good convergence of the numerical model with the experimental results in terms of ‘force-displacement’ relationship is achieved. Finally the parameters defined in the ABAQUS are determined, which have a key impact on the beams response.

Composite beams with indented construction joint – comparison of results of laboratory tests and numerical analysis

“…This model allows to reflect the behavior of concrete in both the compressed and tensioned zones, as well as in zones of complex stress-strain state. The basic parameters describing the concrete behavior in the CDP model were presented in Table 2 based on literature sources [3], [12] and manual recommendations [11]. In order to correctly emulate the non-linear beam behaviour, it was necessary to assume the relation σ-ε (stress-strain) for concrete and steel.…”

“…For reinforcing steel, an elastic-plastic model with hardening was adopted, which reflected the behaviour of the material in the tensile test of the steel sample. A detailed description of this procedure has been described in publications [3], [13]- [16] and in the manual [11]. The composite beam model discreted in the Abaqus software consisted of steel reinforcement, precast element and new concrete.…”

“…The transfer of stress between concrete layers is a pluricasual phenomenon. Its complexity is increased by the fact that the influence of each individual joint mechanism on the stress transfer is different and depends on the load level [1]- [3]. Based on the above statement, a hypothesis was formulated that it is possible to create a virtual model of composite beam with an indented interface, calibrate it on the basis on test results obtained with the use of the DIC method, and then to read out the stress that causes the interface cracking and to portray the crack pattern.…”

Analysis of the Shear Resistance in the Indented Interface Between Two Concrete Parts of Concrete Composite Beam

“… adhesion, depending on the average tensile strength of the weaker jointed concrete,  friction, depending on the surface roughness and normal stress resulting from the external load,  load capacity of stirrups counteracting the stress, resulting from shear friction. The papers [3,5,11] indicate that the simple summation of these three components is incorrect. The studies presented in the paper [3] show that stress exceeding the 15-20% of the yield strength appears in stirrups only when the new concrete is separated from the precast element.…”

Influence of the interface reinforcement on static performance of concrete composite T-shaped beams

“…The authors of this paper have already conducted research on T-shaped composite beams, in which they analysed the influence of the interface location [8], [9] and the influence of variously arranged interface parameters on the static performance of such beams [10]- [13].…”