The present study investigates the role of MgO in local structural changes occurring during the accelerated carbonation of alkali-activated slag(AAS)using synchrotron X-ray diffraction,mercury intrusion porosimetry,th...The present study investigates the role of MgO in local structural changes occurring during the accelerated carbonation of alkali-activated slag(AAS)using synchrotron X-ray diffraction,mercury intrusion porosimetry,thermogravimetry,and nuclear magnetic resonance spectroscopy.The obtained results provide new insight showing that MgO incorporation into AAS reduced Al substitution in C-S-H and led to the formation of secondary phases,which significantly altered the route of carbonation.In particular,the carbonation of secondary phases(i.e.,layered double hydroxide)occurred and reduced the extent of carbonation in C-A-S-H.Consequently,a buffer-like system is provided,showing similar behavior but different principles involved in comparison with those in Portland cement.This effect was found to dramatically reduce the degrees of decalcification,dehydration and polymerization of C-A-S-H under accelerated carbonation conditions.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean gov-ernment(Ministry of Science,ICT&Future Planning)(2015R1A2A1A10055694).
文摘The present study investigates the role of MgO in local structural changes occurring during the accelerated carbonation of alkali-activated slag(AAS)using synchrotron X-ray diffraction,mercury intrusion porosimetry,thermogravimetry,and nuclear magnetic resonance spectroscopy.The obtained results provide new insight showing that MgO incorporation into AAS reduced Al substitution in C-S-H and led to the formation of secondary phases,which significantly altered the route of carbonation.In particular,the carbonation of secondary phases(i.e.,layered double hydroxide)occurred and reduced the extent of carbonation in C-A-S-H.Consequently,a buffer-like system is provided,showing similar behavior but different principles involved in comparison with those in Portland cement.This effect was found to dramatically reduce the degrees of decalcification,dehydration and polymerization of C-A-S-H under accelerated carbonation conditions.
