Understanding the impact of degradation of concrete structures

Dynamically loaded beam failure under corroded conditions

De-icing salts, used on roads in heavy winters, may enter reinforced concrete (RC) structures via its capillary pore system or via cracks, initiating reinforcement corrosion and reducing its remaining service-life. Vehicles passing real bridges exert a dynamic impact action that might activate a fatigue failure mechanism. In order to generate...

Assessment of the crack healing capacity in bacteria-based self-healing concrete (abstract)

Structural monitoring and modal properties of a real time bridge and lab tests

For understanding the actual state of durability of concrete structures, it is important to know its response due to external loading. This response mainly depends on the actual structural and material properties of the structure, while loaded. Mechanical and chemical degradation are the main mechanisms that may affect these properties with time...

Potential of bacteria-based repair solution as healing agent for porous network concrete

Bacterially induced calcium carbonate precipitation has received considerable attention for its potential application in enforcing or repairing construction material. The mechanism of bacterially mediated calcite precipitation in those studies is primarily based on the enzymatic hydrolysis of urea. Besides calcite precipitation, this reaction...

Bacteria-based self-healing concrete for application in the marine environment

Marine concrete structures are exposed to one of the most hostile of natural environments. Many physical and chemical phenomena are usually interdependent and mutually reinforcing in the deterioration of marine exposed concrete: expansion and microcracking due to physical effects increases concrete permeability paving the way for harmful...

Analysis of intergranular crack propagation in brittle polycrystals with a generalized finite element method and network algorithm

Two different approaches to intergranular crack propagation in brittle polycrystals are contrasted. Crack paths resulting from a method that allows a detailed description of the stress field within a polycrystal are compared to cracks dictated by topological considerations. In the first approach, a fracture path is determined with a Generalized...

How to measure path length?

Path length measuring is a relevant engineering problem. Leonardo Da Vinci designed for the military appropriate equipment, the podometer, to do so. Modern equipment such as step meters and map meters are quite similar to Da Vinci?s design, despite geometrical statistical - stereological - methods based on theorems of Cauchy and Buffon that were...

The Influence of Cracks on the Durability and Service Life of Reinforced Concrete Structures in relation to Chloride-Induced Corrosion: A Look from a Different Perspective

The service life of concrete structures can be significantly shortened when corrosion of steel reinforcement occurs, especially in a marine environment and in structures exposed to de-icing salts. The influence of load- or deformation-induced cracks on corrosion progress is an important issue which was studied in this research in relation to the...

Role of microstructural geometry in the deformation and failure of polycrystalline materials

A deeper understanding of the deformation and failure mechanisms in polycrystals is of utmost importance for their reliable use as engineering materials. These mechanisms are strongly influenced by the geometry of the granular arrangement. In this work, two-dimensional intergranular quasi-static crack propagation in brittle polycrystals and...

Un nouveau béton auto-cicatrisant grâce à l’incorporation de bactéries

La formation d’un réseau continu de fissures contribue à l’augmentation de la perméabilité du béton, réduisant ainsi de manière importante sa résistance à l’attaque d’agents agressifs dissous dans l’eau. Afin d’augmenter la capacité de cicatrisation autogène du béton, certains agents cicatrisants spécifiques peuvent être incorporés dans la...