Fast deteriorating and expensive asphalt roads have become one of the greatest challenges facing African countries in recent years. While the cost of asphalt roads slows down urban and transport infrastructure development, non-durable asphalt roads develop cracks and potholes which cause motor accidents and loss of lives every week.

AIMS Cameroon 2015 alumna Aja-Fowé Angèle has just provided a global solution for durable and sustainable asphalt roads. During the defense of her thesis titled “Molecular Modeling of Nanostructured Additives to Asphaltic Materials”, last August 26th, for a degree of Doctor of Science in Computational Materials Science at the Department of Materials and Mechanics of the Institute of Physics, University of São Paulo in Brazil, Aja-Fowé presented her research findings.

“Motivated by the innovation on both production and performance of asphalt pavement, my thesis intended to use multi-scale atomistic simulations to model asphalt and conduct studies of silica nanoparticles modification on the physical properties of the asphalt, to predict the macro-level properties of asphalt. The results obtained in my work were promising to optimize asphalt concrete and predict the physical properties at the engineering level. 

Computational simulation is a powerful tool to investigate the effects of asphalt intrinsic properties.  Multiscale molecular simulations based on Density Functional Theory (DFT), Molecular Docking, and Molecular Dynamics were used to obtain the properties of asphalt that can be used at the macroscale level to predict the performance of asphalt pavement.

It was found that after the silica nanoparticles were added, the mechanical properties of the asphalt significantly improved. The resistance of the asphalt to compressive or flexural strength increased. This mechanical behavior of the modified asphalt models to have higher stress-strain compared to the neat asphalt indicates that the modified models are the strongest and can sustain the highest tensile load in the road pavement.  Also, the resistance of the asphalt to gradual deformations caused by shear or tensile stress increased. Thus, preventing further crack propagation and failure that significantly impact the durability of the road pavement. Indicating a tendency toward suitable and durable asphalt pavement,” she explained to the Examining Committee which was composed of Prof. Dr. Caetano Rodrigues Miranda (supervisor), Prof. Dr. Lucy Vitoria Credidio Assali, Prof. Dr. Adalberto Leandro Faxina, Prof. Dr. Maurice de Koning, and Prof. Dr. Sérgio Brochsztain. The jury appreciated and approved the work.

Aja-Fowé’s research findings are relevant to problems faced by Africans in particular and the world in general.

“While the world is facing problems with the demands for more and better roads, the innovations in both production and performance of asphalt are overriding. In particular, African countries lack paved roads. This is due to the low economies of many of our countries. Road construction and protection require billions of dollars per year. Providing better asphalt for the road pavement will help overcome the demand for asphalt and improve its durability, thereby raising the economies of the African countries. The results of my thesis contribute to Science, Technology, and Industry in Africa. They may allow proposing a molecular model for asphalt with typical compositions found in African crude oil sources, and the design and computational screening of silica nanoparticles as additives to asphalt to improve its mechanical properties and thus, contributes to the sustainability of asphalt pavement in the next generation,” explains Aja-Fowé.

Cameroonian-born Aja-Fowé Angèle is a success story of women in STEM education. After obtaining her BSc in Physics at the University of Dschang in 2012, she started a Master’s degree in Condensed Matter Physics at the University of Dschang but interrupted in 2014 when she was admitted for a Master’s degree course in Mathematical Sciences at African Institute for Mathematical Sciences – AIMS Cameroon. She graduated in 2015 and travelled to Trieste, Italy where she earned a Diploma in Condensed Matter and Statistical Physics at International Centre for Theoretical Physics – ICTP in 2016.

With a Doctor of Science in Computational Materials Science at the Department of Materials and Mechanics of Institute of Physics, University of São Paulo obtained on August 26th, 2021, Aja-Fowé counts prominently among the 342 brilliant Africans groomed by AIMS Cameroon to accelerate Africa’s transformation. Durable and cheaper roads are the best boosters of economic growth in African countries.