Revealing the dark side of Portlandite Clusters in cement paste by circular polarization microscopy

Plane and crossed polarization are the two standard light modes in polarized light microscopy that are widely used to characterize crystalline and amorphous phases in cement-based materials. However, the use of the crossed polarized light mode has been found to be restrictive for studying birefringent phases quantitatively due to the extinction...

Semi- and full quantitative EDS microanalysis of chlorine in reinforced mortars subjected to chloride ingress and carbonation

Energy dispersive X-ray spectrometry (EDS) is a powerful tool for research studies on building materials. Elemental quantification in cementitious phases contained in the concrete microstructure can be performed at an excellent spatial resolution. However, accurate compositional quantification requires a standard-based analysis, whereas...

The interaction of pH, pore solution composition and solid phase composition of carbonated blast furnace slag cement paste activated with aqueous sodium monofluorophosphate

Blast Furnace Slag (BFS) is a waste product of industrial steel production and a common additive in the cement industry in Northern European countries. However, cementitious materials made from slag-rich cement, particularly CEM III /B, are very susceptible to carbonation. Recent investigations have shown that the surface application of aqueous...

EMABM 2015: Proceedings of the 15th Euroseminar on Microscopy Applied to Building Materials, Delft, The Netherlands, 17-19 June 2015

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...

Looking at glass from a different angle: New insights into fracture patterns through transmitted light microscopy

This paper shows the benefit of using transmitted light microscopy together with a Z-scanning software in fractographical analyses of glass. The strength of glass is largely dependent on processes that happen at the microscale. In this research, 52 plates were fractured in a biaxial tensile test. These were divided into five categories according...

Investigation on lithium migration for treating alkali-silica reaction affected concrete

Alkali-silica reaction (ASR) is one of the major deterioration mechanisms that affect numerous concrete structures worldwide. During the reaction, hydroxyl and alkali (sodium and potassium ) ions react with certain siliceous compounds in the aggregate, forming a hygroscopic gel. The gel absorbs water from the cement paste and swells, possibly...

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...

Mechanical, electrical and microstructural properties of cement-based materials in conditions of stray current flow

This investigation presents a comparative study on mechanical properties, electrical resistivity and microstructure of mortar under DC current, compared to mortar in rest (no current) conditions. Monitoring was performed from 24h after casting until 84 days of cement hydration. A current density level of 10 mA/m2 was chosen as a simulation...

Mechanical, electrical and microstructural properties of cement-based materials in conditions of current flow

Corrosion in reinforced concrete structures is not only induced by the penetration of aggressive substances (e.g. chlorides and/or CO2) but also influenced by stray currents. Further, the degradation mechanisms in reinforced cement-based systems due to the combined effect of stray current and chloride penetration have been a serious problem in...

Characterization of Blast Furnace Slag to be used as Road Base Material

In congested areas around the world, traffic has significantly grown beyond expectation both in terms of volume and weight. Any hinder to the traffic causes severe delays resulting not only in economic loss but also in extra pollution of the environment. Therefore, maintenance works are desired to be reduced as much as possible. Application of...

A tool for concrete performance assessment for ASR affected structures: An outlook

This paper outlines a project (namely PAT-ASR) which entails the development of a multi scale material performance assessment model on simulation of alkali silica reaction deployment and its effects on concrete durability. Performance models require a multi scale approach from micro (namely reaction chemistry) to macro level studies (namely...

Surface crack self healing behaviour of mortars with expansive additives (abstract)

Optimizing self-healing mechanism of slag cement concrete under natural carbonation (poster abstract)

Modeling of expansion and cracking due to ASR with a 3D lattice model

It is generally possible to consider modeling of ASR damage in concrete in two main groups: modeling of gel formation and its expansion; modeling of ASR related damage. In this paper, authors take an attempt to combine both: simulating the correct crack formation and the connected concrete expansion. It is aimed to simulate ASR damage in a...