Whereas current concrete structures begin to deteriorate after 50 years, Roman concrete has been holding up for thousands of years. Portland cement has been the most-used ingredient in today’s concrete, but it’s nothing as good as what the Romans had. Instead, the Romans used two different ingredients in their recipe — wait for it — lime and volcanic rock. Shocking, indeed.
Scientists in the United States and Europe have been studying this for quite a while, and after being published in a press release of this month’s Journal of the American Ceramic Society and American Mineralogist, we now know what exactly is so great about Roman concrete:
“The Romans made concrete by mixing lime and volcanic rock. For underwater structures, lime and volcanic ash were mixed to form mortar, and this mortar and volcanic tuff were packed into wooden forms. The seawater instantly triggered a hot chemical reaction. The lime was hydrated – incorporating water molecules into its structure – and reacted with the ash to cement the whole mixture together.”
The best part? Current cement-creation methods have an environmental impact, whereas the Roman’s use of lime and volcanic rock is extremely eco-friendly. Of course, there are a few cons: it takes longer to dry than current concrete. But, now all that needs to be done is to adapt the recipe to today’s standards, and get building.
Via: Berkeley Lab