Carbonation of C-S-H gel and its Effects on the Carbonation Rate in Blended Cement Paste - An Experimental and Modelling Study

Supplementary cementitious materials (SCMs), like fly ash (FA) and blast furnace slag (BFS), are widely used in concrete to partially replace the cement clinker in the production of blended cement or directly replace part of Ordinary Portland cement (OPC) in the concrete. No matter how the SCMs are introduced, they can reduce the cost of...

Accelerated carbonation of ordinary Portland cement paste and its effects on microstructure and transport properties

Coupling of carbonation and chlorides ingress mechanisms is very common in concrete under certain exposure conditions such as coastal environments. The aggravation/ mitigation of corrosion by the existence of carbonation lies on the fact that microstructural changes due to carbonation result in changes on the transport properties of the material...

Carbonation mechanism of alkali-activated fly ash and slag materials: In view of long-term performance predictions

As the building sector is expanding, a growing interest in technologies that can reduce the CO2 emission from concrete production has led to partial replacement of cement with by-products from various industrial processes. Besides the partial replacement of cement, development of alkali activation technology ensures full replacement of cement in...

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...

Interactive mathematical model of self-healing in carbonated cementitious materials

A mathematical model for the post-damage recovery of carbonated cement is described. The model is based on a two-dimensional initial-boundary value problem for a system of partial differential equations. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate, which is incorporated into...

Application of encapsulated lightweight aggregate impregnated with sodium monofluorophosphate as a self-healing agent in blast furnace slag mortar

This paper studies the potential of using expanded clay lightweight aggregate impregnated with sodium monofluorophosphate (Na2FPO3) solution which is eventually encapsulated by a cement paste layer to produce a self-healing system in blast furnace slag cement mortars. It was found that the technique significantly improved the quality of the...

The characterisation, improvement and modelling aspects of Frost Salt Scaling of Cement-Based Materials with a High Slag Content

Blast furnace slag cement concrete is used extensively in a number of countries. In comparison with OPC, it is particularly well known for its excellent performance in marine environments. One dis-advantage of slag cement is its vulnerability to scaling under the combined load of freezing-thawing and de-icing salts. The current investigation was...