Impact of maltene and asphaltene fraction on mechanical behavior and microstructure of bitumen

As a widely accepted concept, bitumen consists of four fractions that can be distinguished by their polarity. Highly polar asphaltene micelles are dispersed in a viscous phase of saturates, aromatics and resins (maltene phase). Different concentrations of asphaltenes in the bitumen result in a range of mechanical response properties. In an...

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...

The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinforced mortar and concrete) are multi-phase...

The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinforced mortar and concrete) are multi-phase...

Microstructure Analysis of Heated Portland Cement Paste

When a concrete structure is exposed to high temperature, the mechanical damage and chemical transformation take place simultaneously, which will change the microstructure of material. On the other hand, the mechanical properties and transport properties depend on the development of microstructure of cement paste. In order to study the...

Effect of Admixed Micelles on the Microstructure Alterations of Reinforced Mortar Subjected to Chloride Induced Corrosion

This paper reports the main results from the influence of the initially admixed nano-aggregates (0.5 g/l PEO113-b-PS70 micelles previously dissolved in demi-water) on microstructural alterations of the reinforced mortar subjected to chloride induced corrosion. The morphology of hydration/corrosion products at the steel/cement paste interface and...

Experimental study on ultrasonic pulse velocity evaluation of the microstructure of cementitious material at early age

This paper describes an ultrasonic experimental set-up to monitor the development of the microstructure of fresh concrete at different temperatures (isothermal curing at 10, 20, 30 and 50 °C) and water/cement ratios (0.40, 0.45 and 0.55). The Ultrasonic Pulse Velocity (UPV) is used as an indication for microstructure development of concrete at...

Application of TEM to characterize fly ash- and slag cements

A Portland fly ash cement containing 20% of a fine fly ash and a blast furnace slag cement of approximately 290 days old were examined with analytical transmission electron microscopy, in order to examine the (local) microstructure in these cements in detail. In the Portland fly ash cement the fly ash reacted with CH resulting from the cement...

Microstructure and properties of styrene acrylate polymer cement concrete

The paper systematically describes the evolution of the microstructure of a styrene acrylate polymer cement concrete in relation to its mechanical properties and durability. The results presented and discussed at the present paper involve the interaction of the polymer dispersion with portland cement; the effect of the polymer modification on...