Some Critical Reflections on the SEM-EDS Microanalysis of the Hydrotalcite-like Phase in Slag Cement Paste

For a better understanding of the hydrotalcite-like phase with SEM-EDS microanalysis, the present research paid special attention to the data acquisition and interpretation of this technique. A lower Mg/Al ratio was obtained when using a higher accelerating voltage, and a beam energy of 10 kV was more appropriate than 15 kV for investigation...

The effect of blast furnace slag chemistry on carbonation characteristics of cement-slag systems

In order to compensate the limited availability of raw material resources and meet the growing demand for decreasing CO2 emissions during cement and concrete productions, a practical method is to decrease the clinker content in cement. This strategy mainly consists of substituting a part of the clinker with supplementary cementitious materials ...

Micro-Mechanical Properties of Slag Rim Formed in Cement–Slag System Evaluated by Nanoindentation Combined with SEM

Slag rim mainly consists of secondary precipitations such as C–S–H gel phase and hydrotalcite-like phase, which originate from the hydration of slag. In this paper, the micro-mechanical properties of slag rim were characterized by nanoindentation in combination with SEM. It was found that, compared to the C–S–H gel phase, slag rim showed about a...

The role of hydrotalcite-like phase and monosulfate in slag cement paste during atmospheric and accelerated carbonation

This paper identified carbonation products in the slag-rich cementitious systems upon three different exposure conditions, namely, long term exposure in the field, indoor natural exposure, and accelerated carbonation testing. Overall, mineralogy of the carbonation products was found to be fundamentally similar under different exposure...

Effect of MgO content on the quantitative role of hydrotalcite-like phase in a cement-slag system during carbonation

This paper reports the carbonation characteristics of a cement-slag system exposed to accelerated carbonation testing, and its improved carbonation resistance with the increasing MgO content in blast furnace slag, in which hydrotalcite-like phase plays a key role. Our research showed that the hydrotalcite-like phase started to carbonate upon...