Self Healing Concrete Engineering Development By Romans

Environmental & Science Education, STEM, History of Science, Archaeology

"Concrete, heal thyself" (What a wonderfully playful short lede!) fronting the full title of an essay by Ars Technica science writer Jennifer Ouellette. It is titled "Ancient Roman concrete could self-heal thanks to 'hot mixing' with quicklime."

The essay explains the function of "lime clasts, dismissed as defects," have "a useful purpose."

 

Ouellette discusses the durability of the Pantheon Dome, the largest unreinforced concrete dome in the world, recipes for Portland cement and Roman concrete, recommendations for construction in the  engineering treatise De architecture, written in 30 CE an the studies of the MIT environmental engineer Adam Masic, which led him to new research.

Ouelette concludes that "Masic et al. found evidence of calcite-filled cracks in other samples of Roman concrete, supporting their hypothesis (that the Roman concrete was heated to high temperatures in its manufacture). They also created concrete samples in the lab with a hot mixing process, using ancient and modern recipes, then deliberately cracked the samples and ran water through them. They found that the cracks in the samples made with hot-mixed quicklime healed completely within two weeks, while the cracks never healed in the samples without quicklime."

The link is here and the article contains links to important terms, including some used above. I add two links 1) to Adam Masic's MIT group. (Admir is his first name but he must also be called Adam routinely.) and 2) to this Ars Tecnica profile of Jennifer Ouellette.