Three series of tensile and creep tests on partially concrete specimens are analyzed by means of the Fictitious Crack Model. Each specimen was loaded to a given softening branch and then unloaded. After that specimen was to a certain percentage…
Three series of tensile and creep tests on partially concrete specimens are analyzed by means of the Fictitious Crack Model. Each specimen was loaded to a given softening branch and then unloaded. After that specimen was to a certain percentage of the unloading start load (six levels 95%) and then the sustained loading started. The material constitutive laws the model were derived tests. The model was applied to the simulation of two series tests, which produced load-deflection curves, creep deflection-time curves and sustained load level-failure time curves. A very satisfactory 1 1 <)lrrt'"'""""r""1'li- between the experimental results and the theoretical simulations is achieved. 1315 1 Cracking is as one of the important factors in creep of concrete structures. Therefore various crack models are adopted in creep analysis of concrete, e.g. Bazant (1985), de Borst (1986). However, time-independent crack models are usually utilized and only time-dependent deformations outside the fracture process zones are taken into account. In most cases it is justified to do so as sustained load levels are low and cracks grow to a limited extent. At high load levels, however, crack propagation may have a dominating on creep processes and eventually lead to failure [Mindess 984), Wittmann (1984)]. In order to simulate creep crack growth and Time-Dependent Fictitious Crack Model has been developed to analyze creep fracture of concrete in bending and compact tests by (1992). During last decades more attention has been paid to post- peak of concrete structures under static loading. Recently, three tensile and flexural creep tests on concrete specimens already loaded to some point after peak-point were performed at ENEL-CRIS, Time-Dependent Fictitious Crack Model was applied to simulation of the tests. The main results are presented below and further details can be found in the internal report by Carpinteri et al.