The powders of the AP ng compositions containing alumina nanoparticles and glass precursors (SiO2, CaO), were prepared to adsorb these nanoparticles on the platelet surface. Alumina nanoparticles Al2O3 (TMDAR, TaiMei), calcium carbonate CaCO3 (Sigma Aldrich) and the colloidal silica SiO2 (Nexsil20K30, Nyacol) were first dispersed in deionized water in the presence of a dispersant (Darvan 7NS, Vanderbilt Minerals LLC) and stirred for 15 minutes. The slurry was then mixed with alumina milling media for 20 hours. Platelets were added for the last three hours only to avoid any excessive breaking. After removing the alumina milling media, the suspension was soaked in liquid nitrogen until completely frozen and then freeze-dried for about 48 hours to remove all water. After this step, a solid cake is obtained, which is de-agglomerated manually with mortar and filtered with a coarse sieve. The powder obtained is finally heat treated for 1 hour at 900°C to remove all traces of organic compounds and to start the decomposition of calcium carbonate CaCO3 to calcium oxide CaO.