RESIDUAL CONCRETE STRENGTH AFTER SUSTAINED LOAD: EXPERIMENTAL RESULTS AND MODELLING APPROACH

Author(s): Zainab Kammouna, Matthieu Briffaut , Yann Malecot
Paper category: Proceedings
Book title: proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Service Life of Cement-Based Materials and Structures
Editor(s): Miguel Azenha, Ivan Gabrijel, Dirk Schlicke, Terje Kanstad and Ole Mejlhede Jensen
ISBN:978-2-35158-170-4
e-ISBN: 978-2-35158-173-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 142-151
Total Pages: 10
Language : English

Abstract: Rheological models for estimating the creep of concrete generally assume that concrete is an
homogeneous material. Therefore, strains incompatibilities between the cement paste and
aggregates when the concrete is subjected to a creep loading cannot be taken into account
whereas they can generate microcracking. These microcracks may cause a decrease of the
elasticity modulus and of the strength of concrete, and an increase in the amount of creep
strains under the same loading level. This increase in creep strains can be considered as the
source of nonlinearity with the stress level. To study the influence of these microcracks on the
mechanical behaviour, compressive creep tests at different loading level (50% and 80% of the
strength) and for different age of loading (1 and 3 month) have been performed followed by
quasi static test to measure the residual concrete strength. Experimental results highlight
different trends with respect to the age of loading. Besides, a viscoelastic-damageable model
has been adopted for calculating creep using a mesoscopic meshing approach. The results
show that a significant proportion of non-linearity can be explained by the microcracks and
that the mesoscopic approach allows to reproduce a strength decrease for hardened concrete.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00