Effects of Meso-scale Modeling on Concrete Fracture Parameters Calculation

Abstract

Mechanical fracture brings about considerable financial and living costs to various communities. Since the early twentieth century, the issue has been scientifically under scrutiny. Hence, it is of necessity to explore the failure of various materials including concrete as one of the most widely used materials in the construction industry. In examining the concrete structures, while it is assumed that concrete is a homogeneous material, it consists of several components such as cement paste, an aggregate of sand, gravel, and air, and the components play an essential role in determining correct concrete behavior. Hence, in the present research, to calculate the concrete fracture parameters under the three-point bending experiment, 100 distributions of aggregates and cement matrix were considered, and fracture factor and integral J were investigated, and contrary to expectations, the second and third fracture modes were also created. Besides, energy release ratio distribution along the beam thickness becomes unsymmetrical, contributing to early failure and crack propagation.

Wave Propagation in Rocks – Investigating the Effect of Rheology

“…"Rocks flow" -they show deviation from prompt elastic behavior, exhibiting creep and relaxation; in general: delayed and damped response. Probably due to the many levels of various mesoscopic length scales in the structure of a rock [1] (see also [2] on principles and [3,4] for related effects), the dampings and delays can be observed at various time scales: seconds, hours, days, years each. Knowing these time scales is important and beneficial: by performing a civil engineering technological step faster than the time scale of a disadvantageous effect, we can prevent the full development of that effect in a simpler and cheaper way.…”