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Center for Nonlinear Studies |
The term geopolymer has become synonymous with alkali-activated slag/fly ash, a cement-like binder material possessing similar mechanical properties to traditional cement at a much lower environmental cost (80-90% less CO2 released). The success of this material in the industrial setting is in large part due to the increasing pressure to use environmentally friendly materials, and with Portland cement accounting for 5-8% of global man-made CO2 emissions, geopolymer concrete is a viable alternative. However, to bring a product to market in this competitive industry requires a strong basis of scientific understanding. Nanoscale studies probing the formation of geopolymer binders and associated structural changes have become a crucial component in determination of geopolymer durability. However, this form of research is hindered by the amorphous and heterogeneous nature of the precursors and final reacted binder, together with the numerous individual reactions occurring in parallel during dissolution of the precursor and formation of the binder. In order to attain a practical alkali-activated geopolymer concrete there has been extensive research into both the real-world material and a variety of associated model systems. Here, we outline how molecular research on these model systems has contributed to understanding the industrially applicable product. Techniques utilized include density functional modeling, local structure analysis from total scattering, coarse-grained Monte Carlo simulations and micro-/nano-tomography. Hence, by understanding the mechanisms responsible for the behavior of model systems, and therefore various aspects of the chemistry of the industrially applicable product especially at the nanoscale, there exists substantial evidence regarding the performance and durability of this new material.
Host: Peter Loxley, loxley@lanl.gov