![]() The research team was led by Paulo Monteiro, a UC Berkeley professor of civil and environmental engineering and a faculty scientist at Berkeley Lab, and Jackson, a UC Berkeley research engineer in civil and environmental engineering. Marie Jackson holds a 2,000-year-old sample of maritime concrete from the first century B.C. Shipping was the lifeline of political, economic and military stability for the Roman Empire, so constructing harbors that would last was critical.” “It is one of the most durable construction materials on the planet, and that was no accident. “Roman concrete has remained coherent and well-consolidated for 2,000 years in aggressive maritime environments,” said Marie Jackson, lead author of both papers. The researchers’ findings are described in two papers, one that was posted online May 28 in the Journal of the American Ceramic Society, and the other scheduled to appear in the October issue of the journal American Mineralogist. The production of lime for Roman concrete, however, is much cleaner, requiring temperatures that are two-thirds of that required for making Portland cement. Seven percent of global carbon dioxide emissions every year comes from this activity. The process for creating Portland cement, a key ingredient in modern concrete, requires fossil fuels to burn calcium carbonate (limestone) and clays at about 1,450 degrees Celsius (2,642 degrees Fahrenheit). The manufacturing of Roman concrete also leaves a smaller carbon footprint than does its modern counterpart. ![]() The discovery could help improve the durability of modern concrete, which within 50 years often shows signs of degradation, particularly in ocean environments. It described for the first time how the extraordinarily stable compound – calcium-aluminum-silicate-hydrate (C-A-S-H) – binds the material used to build some of the most enduring structures in Western civilization. Using the Advanced Light Source at Lawrence Berkeley National Laboratory (Berkeley Lab), a research team from the University of California, Berkeley, examined the fine-scale structure of Roman concrete. Its diameter is 9 centimeters, and it is composed of mortar formulated from lime, volcanic ash and chunks of volcanic tuff. Sample of ancient Roman maritime concrete from Pozzuoli Bay near Naples, Italy.
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