Effect of corrosion on the fatigue service-life on steel and reinforced concrete beams

Chloride-induced corrosion is a point of big concern in reinforced concrete (RC) structures. To monitor the actual health and to predict the remaining service-life of structures, it is important to understand the structural behaviour and the failure mechanism of structures exposed to chlorides under fatigue loading conditions. A beam test,...

Potentiometric response of chloride sensors in cementitious materials of varying chemical composition and water-to-cement ratio

Free chloride ions are the main cause of steel corrosion in reinforced concrete structures. Ag/AgCl electrodes, as chloride sensors, are predominantly sensitive to chloride ions and respond electrochemically to the chloride ion activity in the environment. This is reflected by changes of the open circuit potential (OCP) of the sensors. To...

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...

Evaluation of Ag/AgCI sensors for in-situ monitoring of freee chloride concentration in reinforced concrete structures

The level of free chloride concentration in reinforced concrete structures essentially determines the onset of steel corrosion initiation and further propagation. One of the well-known methods for monitoring free chloride concentration is using silver/silver chloride electrodes (Ag/AgCl). These electrodes are sensitive mainly to chloride ions...

Nondestructive determination of chloride concentration using Ag|AgCl electrodes produced by electrochemical anodization

The stability of chloride ion selective electrodes in highly alkaline solutions is an important aspect when reliability and feasibility within reinforced concrete applications are concerned. The sensitivity of these electrodes largely depends on the properties of the AgCl layer, including uniformity, porosity, orientation, thickness, etc. These...

Non-destructive evaluation of chloride-induced corrosion in reinforced concrete: Electrochemical impedance spectroscopy sheds new light on generally applied sensors performance

Service life of reinforced concrete structures exposed to chloride enriched environment is well known to be mainly determined by steel passivity breakdown in the event of chloride-induced corrosion initiation and propagation. Since Cl- induced (localized) corrosion is caused by the free (water-soluble) chloride, present in the pore network of a...

Bio-inspired control of material properties in civil engineering: Current concept for corrsoion protection via the application of bacteria and bio-polymers

The improvement of material properties of cement-based materials e.g. reduced permeability, porosity, uniform distribution of hydration products, etc. is of a significant importance and related to durability and sustainability of concrete and reinforced concrete structures. With this respect, a recent and novel approach is to "create" self...

Characterization of Portland cement paste using MIP, nanoindentation and esem techniques

The influence of pluronic P123 micelles on corrosion behaviour of steel in cement extract and bulk matrix properties of cement paste

The influence of Pluronic P123 (PEO20-PPO20-PEO70) micelles (of 10 nm size) on the corrosion behaviour of low carbon steel in cement extract (CE) was studied using electrochemical impedance spectroscopy (EIS) and potentio-dynamic polarisation (PDP). Additionally, mercury intrusion porosimetry (MIP) was emplo ed to derive the impact of admixed...

Tailor-made nano materials for corrosion control and improved matrix characteristics in cement-based systems

The effect of electrical current flow on cement-based microstructure: Bulk matrix alterations within cathodic protection in reinforced concrete