In situ study of the reactivity of Calcium Carbonate polymorphs and aluminosilicates during hydration of low-clinker LC3 cement pastes

To pursue the 2050 global Net Neutrality goal, cement industry (producing the most used material worldwide but also emitting about 6% of the global CO2) has to find groundbreaking strategies to reduce the cement and concrete impact. Addingreactive non-cementitious materials to cement formulations is a very promising way to improve the sustainability of construction and building materials. Composite formulations of Cement, Limestone and Calcined Clay (LC3 cements) or pozzolans-based cements, where non-cementitious phases may reach 45% wt.,show synergistic effects between CaCO3 and aluminosilicates. However, aspects as polymorphisms, particle shape and size, aspect ratio and surface activity are expected to play a relevant role are still unstudied. Using in situ s3DXRD e Phase Contrast Tomography (PCT) during LC3 cement hydration can provide a deep insight on the effects of the above mentioned aspects evident to us, up to now, by X-ray diffraction, 27Al/29Si SS NMR and TG/DSC studies.