Analysing the potential use of a low-grade magnesium carbonate by-product as a filler in hot asphalt mixtures

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Pavement Engineering on 2022, available online at: http://www.tandfonline.com10.1080/10298436.2022.2083618.
Climate change and natural resources depletion are leading society towards a more environmentally sustainable approach. In areas such as construction or civil engineering, waste and by-products valorisation could help in the fight against climate change, reducing the consumption of raw materials. Thus, the use of residues or by-products in asphalt mixtures manufacturing as road pavement layers has great potential due to their characteristics and the large number of natural resources required. Thus, this research aims to characterise a flotation sterile (Low-Grade Magnesium Carbonate, LG-MC) generated in the beneficiation process of natural magnesite and analyse its potential use as filler in asphalt mixtures manufacturing. The characterisation of physical, chemical, and microscopic properties of LG-MC was carried out and then its potential use as filler for asphalt mixtures was evaluated using the UCL (Universal de Caracterización de Ligantes) method. The optimum filler/bitumen ratio for the LG-MC was 1.49, higher than that of calcium carbonate, which was 1.33. Results show a protective effect of LG-MC as filler against ageing, both in the short and long-term, reducing losses due to abrasion.
This work was supported under Grant FJC-2018-035747-I funded by MCIN/AEI/10.13039/501100011033; by the Magnesitas Navarras S.A. under Grant FGB 311127; and Government of Catalonia under Grant FI-DGR 2020.
Peer Reviewed
Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura
Postprint (author's final draft)