PRELIMINARY NUMERICAL ASSESSMENT OF MICROCRACKING CAUSED BY AUTOGENOUS SHRINKAGE IN A HETEROGENEOUS SYSTEM

Abstract

The majority of research that has been performed on the restrained shrinkage cracking behavior of concrete has assumed that concrete acts as a homogeneous material. While this assumption enables the potential for through cracking to be assessed, it does not provide realistic information on the damage that may develop as a result of the heterogenous nature of the composite (i.e., microcracking). This research uses an object oriented finite element analysis (OOF) to. simulate the behavior of the concrete on a meso-scale by considering it as a two-phase system of 'inert aggregates' and 'shrinking paste'. The meso-scale composite images used in the simulations were directly obtained from mortar samples. The procedure of acquiring the images, analyzing the images to enable phase separation, meshing the finite element model, performing the simulation, and analyzing the results is discussed. This paper illustrates how concrete composites could be analyzed on the meso-scale as well as how this information can be used to improve the design of concrete.