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December 9, 2025<\/p>\n
2 min read<\/p>\n
Add Us On Google<\/span>Add SciAm<\/span><\/span><\/p>\n Pompeii Time Capsule Reveals Secrets to Durable Ancient Roman Cement<\/p>\n Lime granules trapped in ancient walls show Romans relied on a reactive hot-mix method to making concrete that could now inspire modern engineers<\/p>\n By Humberto Basilio edited by Andrea Thompson<\/span><\/p>\n The so-called aqueduct de les Ferreres, also known as Puente del Diablo, is a Roman arcade that is part of the aqueduct that supplied water from the Francol\u00ed river to the city of Tarraco (Tarragona), from a distance of 25 kilometers.<\/p>\n Sergi Reboredo\/VW Pics\/Universal Images Group via Getty Images<\/p>\n Ancient Romans built arched bridges, waterproof port infrastructure and aqueducts that enabled the rise of their empire and that are still standing\u2014and often still used. They did so with a type of cement that is far sturdier than what is used today, but exactly how Roman cement was made was something of a mystery. Now researchers have found proof of an explanation they had proposed in 2023 that could offer insights into how to build longer-lasting concrete today.<\/p>\n In his first-century B.C.E. work De Architectura, Vitruvius, one of the most famous architects of the Roman Empire, described Roman cement as being made with what we today call slaked lime, or hydrated, heated limestone. But based on the discovery of the makeup of chunks called \u201clime clasts\u201d found at a previous excavation in Pompeii, Massachusetts Institute of Technology environmental engineer Admir Masic and his colleagues proposed in a 2023 paper that ancient builders instead used a process called \u201chot mixing.\u201d In this method, highly reactive quicklime (dry heated limestone) is mixed with volcanic ash and water, setting off a chemical reaction that produces heat and gives the material self-healing capabilities.<\/p>\n To reaffirm his discovery, Masic and his team returned to Pompeii in 2024 and visited a house that was under renovation when Mount Vesuvius erupted, freezing the place in time. \u201cI literally felt like I was a worker in 79 C.E.,\u201d Masic says.<\/p>\n Inside one of the rooms, among stones, roof tiles and tools, the researchers found large piles of dry, premixed mortar ingredients\u2014a blend of volcanic ash and granules of quicklime\u2014waiting to be hydrated and applied to walls, Masic says.<\/p>\n Rows of ceramic roof tiles and a stack of yellow tuff blocks in Atrium 2 of the newly excavated Regio IX (Archaeological Park of Pompeii), showing materials prepared for the ongoing reconstruction works.<\/p>\n Archaeological Park of Pompeii<\/p>\n The team also showed that the lime clasts\u2014previous thought to be impurities from incomplete mixing\u2014had the distinctive physical and chemical characteristics that could only be produced by a technique in which water was added to the quicklime and ash mixture, not by the method Vitruvius wrote about. The researchers published their results on Tuesday in Nature Communications.<\/p>\n The hot mixing method creates the fragmented, highly porous lime clasts within the mortar that allow calcium to easily travel through the material and recrystallize to fill cracks. Understanding and mastering this \u201cself-healing\u201d technology will allow engineers to use the technique in modern construction. Modern cement is made by heating limestone and clay in giant kilns to form a material called clinker, which is ground into a powder and mixed with water on-site to make concrete. It is strong but short-lived, often cracking and degrading within decades.<\/p>\n The findings will also enable restorers to repair the remains of the Roman Empire with a more compatible approach. \u201cWe will definitely have new recipes for restoration that will come out of this,\u201d Masic says.<\/p>\n \u201cFew topics in Roman archaeology are more worth our attention than the development of concrete,\u201d says archaeologist Tom Brughmans of Aarhus University in Denmark, who was not involved in the study. The new research is \u201csimply a beautiful observation, an archaeologist\u2019s dream.\u201d<\/p>\n If you enjoyed this article, I\u2019d like to ask for your support. Scientific American<\/span> has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.<\/p>\n I\u2019ve been a Scientific American<\/span> subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm <\/span>always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.<\/p>\n If you subscribe to Scientific American<\/span>, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.<\/p>\n In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.<\/p>\n There has never been a more important time for us to stand up and show why science matters. I hope you\u2019ll support us in that mission.<\/p>\n","protected":false},"excerpt":{"rendered":" December 9, 2025 2 min read Add Us On GoogleAdd SciAm Pompeii Time Capsule Reveals Secrets to Durable Ancient Roman Cement Lime granules trapped in ancient walls show Romans relied on a reactive hot-mix method to making concrete that could now inspire modern engineers By Humberto Basilio edited by Andrea Thompson The so-called aqueduct de<\/p>\n","protected":false},"author":1,"featured_media":36673,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[20431,4906,671,20430,8068,572,2827,5686],"class_list":{"0":"post-36672","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-cement","9":"tag-frozen","10":"tag-house","11":"tag-midrenovation","12":"tag-pompeii","13":"tag-reveals","14":"tag-roman","15":"tag-secrets"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/36672","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=36672"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/36672\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/36673"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=36672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=36672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=36672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}It\u2019s Time to Stand Up for Science<\/h2>\n