CURRENT RESEARCH PROJECTS

Strong and Multifunctional Geopolymer Composites: A Multi-Scale Study

Geo polymers are amorphous inorganic polymers that result from the reaction between an aluminosilicate source and an alkali metal hydroxide or silicate solution. They present various appealing attributes such as rapid hardening, early strength, low shrinkage, freeze-thaw resistance and excellent acid resistance.  The research objective is to build novel multi-scale computational approaches that can connect the effective response to the micro- and nano- constituents.  The project will promote the use of geopolymer composites as low-carbon Portland cement alternative, low-level nuclear waste containment, heavy metal waste encapsulation, and biomaterials for bone regeneration.

Funding source: National Science Foundation.

Publications:

  • Akono, A.T., Koric, S. and Kriven, W.M., 2019. Influence of pore structure on the strength behavior of particle-and fiber-reinforced metakaolin-based geopolymer composites. Cement and Concrete Composites, 104, p.103361.
  • Akono, A.T., Fracture Behavior of Metakaolin-based Geopolymer Reinforced with Carbon Nanofibers, International Journal of Ceramic Engineering and Science, In press, (2020).

Fracture Characterization of Hard Biomineralized Tissues

Bone fracture is prevalent in developed countries with an estimate of two fracture events per individual over the course of their lifetime. The same is for osteoporosis–metabolic bone leading to increase leading to increased brittleness—which affect one in every two women and one in every five men over the age of fifty. The underlying scientific challenge is an in-depth understanding of the determinants of fracture resistance in cortical bone. Our research objective is to investigate fracture mechanisms in hard biomineralized tissues at the nanoscale.

Publications

  • Amrita Kataruka, Kavya Mendu, Orieka Okeoghene, Jasmine Puthuvelil, Ange-Therese Akono, Microscopic assessment of bone toughness using scratch tests, Bone Reports, Vol. 6, pp. 17-25, (2017)
  • Ange Therese Akono, Fracture Resistance of Biological Tissues: A Theoretical and Experimental Study, 2nd Health Care Engineering Systems Symposiums, Champaign, Illinois. September 14th 2015.
  • Ange-Therese Akono, From Butter to Bone Tissues: Assessing the Fracture Resistance via Scratch Testing, p. 96 . In: Proceedings of the 13th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials [Blucher Material Science Proceedings, v.1, n.1]. São Paulo: Blucher, 2014. ISSN 2358-9337.

Fundamental Studies of Recycled Aggregate Concrete

Recycling demolition and natural disaster concrete waste for new concrete production offers a sustainable approach to supply the rising demand of sand, but remains poorly utilized. The basic idea consists in reusing crushed old concrete from demolition projects, estimated at 200M tons per year in the United States alone, to cast new concrete. The research goal is to improve the performance of recycled aggregates to transform them into a suitable alternative to sand.

Publications

  • Ange-Therese Akono, Mimi Zhan, Jiaxin Chen, Surendra P Shah, Nanoporosity of Calcium-Silicate-Hydrates in Fine Recycled Concrete Aggregate Mortars, Cement and Concrete Composites, In Press.
  • Ange-Therese Akono, Jiaxin Chen, Mimi Zhan, Surendra P. Shah, Basic Creep and Fracture Response of Fine Recycled Aggregate Concrete, Journal of Construction and Building Materials, In Press.

Geochemical Reactions Within the Context of CO2 Geological Sequestration

Geologic carbon sequestration in deep saline aquifers is an emerging approach for mitigating climate change by trapping CO2 in suitable geological formations. The research objective is to explore the influence of rock-fluid interactions on  the microstructure, composition, and mechanical characteristics. Furthermore, a full knowledge of geochemical reactions in reservoir conditions and their implications on mechanical integrity will inform exploratory field studies of CO2 geological capture and storage.

Funding Source: U. S. Department of Energy, Center for Geological Storage of CO2.

Publications:

  • Ange-Therese Akono, Jennifer L. Druhan, Gabriela Dávila, Theodore Tsotsis, Kristian Jessen, Samantha Fuchs, Dustin Crandall, Zhuofan Shi, Laura Dalton, Mary K. Tkach, Angela L. Goodman, Scott Frailey, Charles J. Werth, A Review of Geo-Chemical-Mechanical Impacts in Geological Carbon Storage Reservoirs, Greenhouse Gases: Science and Technology, DOI: 1002/ghg.1870, (2019).
  • Fuchs, S.J., Espinoza, D.N., Lopano, C., Akono, A.-T., and Werth, C.J, Geochemical and geomechanical alteration of Mount Simon reservoir rock by CO2-saturated brine following carbon sequestration, International Journal of Greenhouse Gas Control, In Press, (2019).
  • Ange-Therese Akono, Pooyan Kabir, Zhuofan Shi, Samantha Fuchs, Theodore Tsotsis, Kristian Jessen, Charles J Werth, Modeling CO2-Induced Alterations in Mt. Simon Sandstone via Nanomechanics, Rock Mechanics and Rock Engineering, DOI: https://doi.org/10.1007/s00603-018-1655-2, (2018).
  • Ange-Therese Akono, Theodore T. Tsotsis, Charles J. Werth, Alteration of the Fracture Behavior in Host Rock During CO2 Geological Sequestration, 10th International Conference on Fracture Mechanics of Concrete and Concrete Structures, FraMCos-X, Bayonne, France, June 2019. DOI: 10.21012/FC10.235480.
  • Kabir Pooyan, Ange-Therese Akono, Fluid-Rock Reactions in Mt. Simon Sandstone at Microscopic Length-Scale, ARMA 18–219, American Rock Mechanics Association, 52nd meeting, Seattle, June 2018

Nanomechanics of Gas Shale

Gas shale is relevant in many energy-related applications such as hydraulic fracturing in unconventional reservoirs, nuclear waste storage, or carbon dioxide geological capture and sequestration. The challenge consists in relating the mechanical performance of organic-rich shale to the structure and composition at different length-scales.  A hierarchical material, gas shale is extremely heterogeneous and strong controls are needed to offset the influence of extrinsic parameters on the resulting behavior.  Our approach is focused on depth-sensing methods, advanced multi-scale modelling and advanced imaging.

Publications