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The fracture with the formation of crack patterns instead of a single main crack may occur in the structures for several reasons. The main factor is always the presence of high gradients through the depth of a structure at almost constant stresses near the surface. In this case a growing crack can get into the zone of low stresses and stop, and the fracture will continue by formation of new cracks. Such fracture type is typical for heat-stressed structures, but can also occur under mechanical loading. This paper discusses the possible mechanisms of the crack pattern formation. It is shown that in addition to the form of stress field, the fracture type depends on material properties - in particular, its creep. The considered fracture by crack pattern formation could be characteristic of not only the metallic structural elements, but also for the natural formations, for instance rock or ice massives. [ABSTRACT FROM AUTHOR]

Previous studies concluded that inclusions highly influence the initial cracking and propagation of the surrounding mortar. This initial cracking and propagation further affects the specimen's compression strength. It was also shown that the ratio of the inclusion area with respect to the mortar and the inclusion configuration determine the stress levels where cracking starts. The stress concentrations were especially pronounced for the inclusions with sharp angles in the line of loading. This paper evaluates the influence of the inclusion-to-mortar area ratio and the inclusion angle to the micro-crack behaviour and compression strength of a single-inclusion mortar specimen. Visual observations to the specimen's behaviours under increasing load were accessed, and the STRAND7 software was utilized to study the stress distributions and concentrations of the mortar area adjacent to the interface between the aggregate and mortar. [ABSTRACT FROM AUTHOR]

Abstract: The paper is concerned with numerical modeling of corrosion of steel reinforcement in the reinforced concrete. The cracking response of the reinforced concrete beams due to the corrosion effect of the steel reinforcement and due to the load effects was analyzed. The effect of corrosion was simulated by the nonlinear numerical analysis with the FEM program using the 3D model. [Copyright &y& Elsevier]

Abstract: Analytical study on cracking behavior of concrete due to rebar corrosion in the cases of multi-rebar specimens with various rebar spacings, of specimens with locally corroded rebar and specimens with pitting corrosion rebar was carried out. Three-dimensional Rigid-Body-Spring-Method (RBSM) with three phase material corrosion expansion model was applied to simulate crack initiation, internal cracking patterns and crack width propagation. It was confirmed that rebar spacing, ratio of local corrosion length and rebar length and pitting corrosion pattern played important roles in the cracking behavior. [Copyright &y& Elsevier]