I love these base-level, practical advances where even a slight improvement in a formula (provided it is not closely guarded) can, say, improve the strength of a material by 5-10%, meaning that much less of it must be used, which at a scale like concrete's can make for huge changes in usage, markets, processes etc.
Concrete is a HUGE greenhouse gas source, so this is also a great boon for the environment. It's estimated that concrete is responsible for 5% of all anthropogenic CO2.
Utilizing scanning electron microscopy, they discovered mineral compounds and air bubbles in samples of the limestone pyramid blocks that do not occur in natural limestone.
This may be a stupid question, but given the apparent interest and knowledge of concrete in the comments here, it seems like an appropriate time and place to ask:
Why can't they make coloured concrete?
Painting it doesn't seem to last/work. It is grey, always grey. Is there no way to apply colour to the mixture and retain its strength?
Bonus 3) Nanomaterials add a lot of new potential for strength, possibly color, as well as completely new applications. For instance, carbon nanotubes make concrete slightly electrically conductive, which makes it possible to do easy integrity testing, visible from low voltage current fluctuations near stresses, strains, cracks, etc. I wish I had more info on a prospective range of applications here.
Aside A) Clays (of possibly many colors) can also provide an even cheaper, more readily available, and similarly strong building material. Sindhi researchers pre-stressed and baked some test beams, and they were just about as strong as comparable concrete. See Emergence of New Era for Reinforced Baked Clay Construction (Memon, Bhatti, & Ansari): http://www.quest.edu.pk/rjournals/julydec2013/julydec2013_1.... I sincerely wonder how this ongoing wealth of research on concrete plus many generations old, likely undocumented, skill we have with clay construction could come together.
Thanks for the link, but it is in the article. On news.mit.edu articles, when they do include links to papers, the links are presented in the "RELATED" list on the right side. They don't always remember to give links to papers, but they are better about it than the press/news sites of most universities.
> In recent years it has been shown that the structures of a wide variety of colloidal aggregates can be described in terms of the concepts of fractal geometry. The purpose of this review is to discuss some of the evidence for fractal geometry in experimental systems and indicate how fractal geometry can be used to develop a better understanding of their aggregation kinetics and physical properties.
