Exploring olivine-based cements for sustainable construction
|The production of traditional Portland cement is responsible for a significant share of global carbon emissions. An alternative could be found in acid-base cements, specifically phosphate-based binders, such as magnesium phosphate cements (MPCs), which show impressive mechanical properties and durability. However, the high energy needed to produce raw materials, such as magnesium oxide, limits their use. A potential solution to this problem lies in the use of a naturally abundant mineral: olivine.
The reaction between olivine and phosphoric acid is central to the development of these alternative cements. To evaluate the materials structure at the micro and molecular level, and to better understand the underlying reaction mechanisms, Dr Davide Bernasconi (University of Torino), Dr. Alexey Maximenko (National Synchrotron Radiation Centre SOLARIS) and colleagues used several complementary techniques, such as Phosphous X-ray Absorption Spectroscopy Scientists demonstrated that the cement formation process is influenced by factors such as the acid concentration, the liquid-to-solid mass ratio, and the water content in the raw mix. Moreover, up to 57 % of olivine reactivity, whose dissolution was promoted by the curing temperature of 60 °C and low pH, has been achieved. This allowed the development of a dense matrix that reached 75 Mpa of compressive strength.
The development of olivine-based MPCs represents a significant step toward greener construction materials, and ongoing research will help refine these methods to ensure they can be implemented on a larger scale.
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