Atomic structure and phase assemblages in novel M-(N)-A-S-H materials

This paper investigates the atomic structure and phase assemblages in new sodium-stabilized magnesium aluminosilicate hydrate (M-(N)-A-S-H) cementitious binders. Results indicate that absence of Ca2+, Mg2+ promotes a binder Si-Al tetrahedral sheets octahedral Mg with hydrated Na+ cations likely interlayer sites similar to trioctahedral micas (phyllosilicates). NMR studies verify incorporation Al silicate sheets. XRD demonstrates ability these regions nucleate form zeolites (i.e., sodalite) as well formation Mg-Al layered double hydroxide (LDH) phases meixnerite), which is expected due high concentrations Al. TGA results M-(N)-A-S-H possesses chemically bound water hydroxyl units other These evince critical role unique structures durability-linked low-calcium alkali-activated materials.