From sequentially linear analysis to incremental sequentially linear analysis: Robust algorithms for solving the non-linear equations of structures of quasi-brittle materials

It is difficult to accurately predict the strength of masonry and concrete structures. The most widely used method for simulating their behaviour is finite element analysis with the Newton-Raphson method and arch length control. However, the Newton-Raphson method can diverge and not produce a result, for example in bifurcations or during snap...

A new computational approach towards the simulation of concrete structures under impulsive loading

Extraordinary actions such as blast loadings and high velocity impact are rare, but usually have devastating effects. Thus, making critical infrastructures, such as military and governmental facilities, power-plants, dams, bridges, hospitals, etc., more resilient against these hazards is one of the best ways to protect ourselves and our...

Concrete in dynamic tension: The fracture process

The fracture properties of concrete are rate dependent. In this thesis the results on tensile tests at static, moderate and high loading rate are presented. The results show the influence of the loading rate not only the tensile strength, but also on the fracture energy, stress-defromation relation and fracture parameters, like fracture lengths...

Electrochemical lithium migration to mitigate alkali-silica reaction in existing concrete structures

Alkali-silica reaction (ASR) is a deterioration process that affects the durability of concrete structures worldwide. During the reaction, hydroxyl and alkali ions present in the pore solution react with reactive silica from the aggregate, forming a hygroscopic ASR gel. Alternatively, the silica structure is attacked by hydroxyl ions and the...

The Deteriorating Impact of Alkali-Silica Reaction on Concrete: Expansion and Mechanical Properties

The assessment of concrete structures affected by alkali-silica reaction (ASR) is a complex problem due to the multiscale nature of this long-term phenomenon. The reaction starts within the concrete constituents with the formation of an expansive alkali-silica gel at reaction products level. Being the expansive gel confined within the concrete...

Multiscale Modeling of Fracture Processes in Cementitious Materials

Concrete is a composite construction material, which is composed primarily of coarse aggregates, sands and cement paste. The fracture processes in concrete are complicated, because of the multiscale and multiphase nature of the material. In the past decades, comprehensive effort has been put to study the cracks evolution in concrete, both...

Drying shrinkage microcracking in cement-based materials