Modelling the influence of cracking and healing on modal properties of concrete beams

Concrete structures are commonly cracked when in service. To overcome issues arising from cracking, self-healing concrete is being developed. Together with the development of the material, techniques to verify and quantify self-healing are being developed. A number of destructive techniques have been used in the past. It would be beneficial to...

Using nano-indentation and microscopy to obtain mechanical properties

Simulation of mechanical behaviour of heterogeneous materials is only possible if the local properties of the components are known. In recent years nano-indentation is being applied on different levels to obtain local mechanical properties. The aim of this paper is to explore various ways to obtain these properties by combining nano-indentation...

Multi-scale characterization and modelling of damage evolution in nuclear Gilsocarbon graphite

In the present work, the microstructure and mechanical properties of Gilsocarbon graphite have been characterized over a range of length-scales. Optical imaging, combined with 3D X-ray computed tomography and 3D high-resolution tomography based on focus ion beam milling has been adopted for microstructural characterization. A range of small...

Damage induced by continued corrosion in concrete repair systems

Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. After the repair, corrosion of the steel might continue and even accelerate. While the development of the corrosion cell depends on many parameters and is difficult to control, the occurrence of visible damage in some cases can be delayed and...

A modelling study of drying shrinkage damage in concrete repair systems

Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems (Martinola, Sadouki et al. 2001, Beushausen and Alexander 2007). Magnitude of induced stresses depends on many factors, for example the amount of restraint, moisture gradients caused by different curing...

Chloride ingress in cracked concrete studied using laser induced breakdown spectroscopy

Cracks are always present in reinforced concrete structures. It is a goal of the current research to study the influence of mechanical cracks on chloride ingress. A compact reinforced concrete specimen was designed, mimicking the cracking behaviour of beam elements. Cracks of different widths were induced by means of mechanical loading. These...

Lattice based simulation of chloride ingress in uncracked and cracked concrete: Model validation

Impact of surface roughness on the debonding mechanism in concrete repairs

Surface roughness of the existing concrete substrate was considered to have the greatest impact on the bond strength in repair systems. However, the influence of this parameter has been subject for debates in recent years. The effect of concrete surface roughness is not quite clear, nor there exist a clear relation between the surface roughness...

Relationship between cracking and electrical resistance in reinforced and unreinforced concrete

Modelling chloride diffusion in cracked concrete: A lattice approach

In this paper, a 3D lattice model is proposed as a tool to simulate chloride diffusion in (cracked) cement based materials. The procedure consists of two (computationally independent) steps: simulating fracture with the fracture lattice model, previously developed, and simulating chloride diffusion process using the newly developed transport...

Lattice model as a tool for modelling transport phenomena in cement based composites

Meso-scale simulation of chloride ingress in cracked concrete