In the future, the research focus will likely move from the microstructure created by the bridges and dams to the nanostructure of the bridges and dams themselves. For example, silica fume has a significant influence on the nanostructure of the dams, as illustrated by its large (up to 25X) influence on transport through the C-S-H gel [29]. As shown above, alkalis also definitely influence the nanostructure and crystallinity of the C-S-H gel. The nanostructure of the C-S-H gel is already being extensively studied, and atomic and nanostructure-level models are being advanced [28, 30, 31]. The ultimate engineering of the microstructure of cement-based materials will reach fruition only when the nanostructures of the bridges and dams comprising its building blocks are understood and predictable.