Civil and Environmental Engineering
 
 
Multiscale Durability of Nano/Microfiber Reinforced Cement-Based Composites

Complex, time-dependent, and multi-scale interactions exist between the surrounding environment and the aging processes of cement-based composites. Over its lifetime, the material is subjected to combinations of coupled, physical, chemical, and mechanical degradation processes that lead to a breakdown of the matrix microstructure and the eventual weakening of the material integrity. A variety of environmental weathering forces (water, carbon dioxide, salts, and temperature changes) result in internal chemical changes that cause a build up of localized internal stresses due to expansion, shrinkage, and loss of cohesion of the paste. These stresses lead to material damage via initiation of micro-cracks, the propagation of macro-cracks, and the ultimate failure of the material.

 

Our group looks at the problem from an integrated approach that differs from conventional approaches by breaking the problem into its elementary components at different scales with an emphasis on the mechanisms and failure modes at the reinforcement-cement interface.

We utilizes state-of-the-art experimental characterizations (mechanical, chemical, and physical) of weathering mechanisms across multiple length scales (nano to macro) in combination with computational analysis, including molecular dynamics simulation and coupled geochemical speciation and mass transfer modeling, to further elucidate the failure modes of fiber–cement interfaces.

 

Selected References

"Multi-scale performance and durability of carbon nanofibers/cement composites," F. Sanchez, L. Zhang, and C. Ince, In: Nanotechnology in Construction 3: Proceedings of the NICOM3, Springer Proceedings in Physics, Zdenek Bittnar (Editor), Peter J M Bartos (Editor), J. Zeman (Editor), Jiri Nemecek (Editor), V. Smilauer (Editor), 438p., 2009. View Abstract.

"Effect of decalcification on the performance of carbon microfiber reinforced cement-based materials," F. Sanchez, A. Borwankar, and C. Ince. RILEM Proceedings Book related to the NUCPERF 2009 Workshop (Long Term Performance of Cementitious Barriers and Reinforced Concrete in Nuclear Power Plants and Waste Management (EFC Event n°317)). 30 March – 2 April 2009, Cadarache, France. e-ISBN 978-2-35158-087-5, 119-124, 2009. View Abstract.