X-ray diffraction, cements and environment, three worlds in one.

摘要: This keynote lecture will be focused on the strategies for reducing CO 2 emissions in cement production. Concretely, production of ecocements with optimised formulations that yield reductions up to 25%, when compared OPC Phase assemblage has carefully competitive and these new should develop compressive strengths at least 50 MPa 28 days hydration. Optimised compositions several discussed, but all them are ye'elimite or calcium sulphoaluminate containing ones: belite-ye'elimite-ferrite (BYF), belite-alite-ye'elimite (BAY) rich ones (CSA). The clinkering temperature BYF BAY established obtain targeted phase assemblages. Moreover, stabilisation alpha-forms belite is needed high mechanical early ages. benefits use waste materials (such as fly ash slag) additions three-fold: lower due clinker replacement; valorisation “useless” products need a lot landscape consequent efficient consumption raw materials; enhance properties corresponding mortars. design appropriate CSA, mortars, final aim knowing controlling hydration mechanisms, presented. Particularly, role i) type amount set regulator (gypsum, anhydrite, etc.), ii) water/cement ratio (w/c); iii) superplasticiser; iv) pozzolanic discussed. parameters microstructure hydraulic behaviour been investigated through traditional techniques well advanced synchrotron characterisation. formers include laboratory/synchrotron X-ray powder diffraction combined Rietveld methodology (to assemblage), electron microscopy paste determination, rheological studies control effect different additives, w/c setting time retarders) tests (setting times, dimensional stability). latters comprise group available synchrotrons such as: x-ray total scattering data analysed by pair distribution function, PDF.