Cement-based composites reinforced with localized and magnetically oriented Al2O3 microplatelets

The aim of this study is to investigate the use of stiff, inorganic microplatelets as potential reinforcing elements in cementitious systems. The microplatelets are made magnetically responsive to control their orientation and spatial distribution in the cement matrix via a magnetic field and to thus take full advantage of the expected reinforcing effect. Flexural and fracture toughness tests showed that composites exhibiting localized and aligned reinforcement architectures can be up to 50–60% stronger, stiffer and tougher than compositions with randomly distributed microplatelets. By targeting reinforcement at the largely unexploited microscale, the strength and toughness of current cement-based materials showing comparable porosities can be increased by two- to three-fold. This simple and effective approach allows for the reduction of the cement fraction in cementitious systems without impairing its final mechanical performance. Such a strategy may lead to more sustainable cementitious systems, potentially reducing the carbon footprint and energy demand associated with cement manufacture.