This paper analysis failure mechanisms and apparent size effects the biaxial tensile-compressive behaviour of concrete. To this end, a probabilistic discret crack model is used, to determine numerically failure surfaces in the tensile-tensile and tensile-compressive loading range, on account of…
This paper analysis failure mechanisms and apparent size effects the biaxial tensile-compressive behaviour of concrete. To this end, a probabilistic discret crack model is used, to determine numerically failure surfaces in the tensile-tensile and tensile-compressive loading range, on account of size effects considered as volume effects. The results (failure- mechanisms, crack-patterns, volume effects, etc.) are discussed in some details with respect to the loading state applied. Size effects on the failure surface are quantified in terms of stress-invariant ratios at peak load for 8 loading paths. It is found that size effects decrease with the hydrostatic pressure increasing, i.e. when passing from the tensile loading range into the tensile-compressive range. This can be explained by the activation of friction at the crack lips in a stable crack propagation, which regularize mechanical volume effects, and thus apparent size effects. 543 1 of concrete are well studied (see, a 1 ). Less is known about these effects when passing tension domain into the biaxial most of the loading states of concrete domain, whence the importance to ascertain the quantifying size effects in this loading range. ~.._," .......... ,,",_ is of great importance for continuous models of (plasticity, damage etc.), which require material surface in this domain. failure mechanisms and apparent size 7 ..... ...,, ...... o.n-ror•m·n ... c•"'".',. "' behaviour of concrete. To this end, a model is used, to determine numerically and tensile-compressive loading ,..,...,...,.,...,...,_,., considered as volume effects. The results ..,. ....... .,...., ......... ..,. volume effects, etc.) are discussed some loading state applied. Some assumptions mechanisms which can explain this ""'.._. ........... Ulj;;., range are then proposed. These assumptions numerical results obtained.